JP2018161815A - Laminate for control panel and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having excellent designability and chemical resistance.SOLUTION: There is provided a laminate for control panel containing a transparent member, a reflection layer and an adhesive layer (A) in contact with a first surface of the transparent member and a first surface of the reflection layer, in which the reflection layer consists of a cured article of a cholesteric liquid crystal composition and the reflection layer satisfies following formulae (i) to (vi): Ref(ini)≥300nm (i) Ha(ini)≤1% (ii) (Ref(ini)-Ref(NaOH))/Ref(ini)≤0.05 (iii) (Ref(ini)-Ref(EtOH))/Ref(ini)≤0.05 (iv) (Ha(NaOH)-Ha(ini))/Ha(ini)≤0.05 (v) (Ha(EtOH)-Ha(ini))/Ha(ini)≤0.05 (vi).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an operation panel laminate and a method for manufacturing the same.

Reflecting the diversification of lifestyles, the design of products has increased their value in recent years. For example, with regard to the design on the door surface of home appliances, a device adapted to the lifestyle is made (Cited document 1).
In recent years, touch panels have become mainstream, and an operation panel unit of home appliances employs a method that uses a change in capacitance (Cited document 2). Home appliances have been proposed that display operation icons, etc. only when in use to improve visibility, and turn off the operation panel when not in use to achieve a clean appearance and improved design (quoted) Reference 3).
By the way, conventionally, in order to decorate the housing surface of home appliances, methods such as painting, metal vapor deposition, and plating have been often used. However, since it can cope with product shapes that have become complicated in recent years and can realize various functions, a decorative film such as a colored film, a vapor deposition film, and a printing film is transferred or bonded to the surface of the housing. A technique is used, and in particular, a decorative film that does not contain metal is used because it has less environmental burden and is advantageous in terms of cost.
As a decorative film that does not contain a metal, a film obtained by alternately laminating a large number of resin layers having different refractive indexes with controlled thicknesses (Patent Document 4) was obtained by alternately laminating a large number of layers of two kinds of materials. A decorative film in which two layers of a film having properties as a half mirror (Patent Document 5 and Patent Document 6) and a resin film having cholesteric regularity are generated by controlling the refractive index of the laminate. A film (Patent Document 7) has been proposed.

JP 05-288458 A JP 2006-304077 A JP 2014-040960 A JP 2008-200701 A International Publication No. 1993/015906 International Publication No. 1995/017303 JP 2010-111104 A

As a film used for an operation panel included in home appliances or the like, there is an increasing demand for a film having a half mirror property that is metallic and less colored, that is, has a silver appearance and has light transmittance. However, a film having chemical resistance such as alkali resistance and alcohol resistance that can withstand cleaning with an alkaline detergent and ethanol has not yet been obtained.
An object of this invention is to provide the laminated body provided with the outstanding designability and chemical-resistance which can be used for an operation panel.

As a result of intensive studies, the present inventors have found that the above problem can be solved by a laminate including a reflective layer that satisfies a predetermined requirement.
That is, the present invention is as follows.

[1] A transparent member, a reflective layer, and an adhesive layer (A) in contact with the first surface of the transparent member and the first surface of the reflective layer,
The reflective layer is made of a cured product of a cholesteric liquid crystal composition, and the reflective layer satisfies the following formulas (i) to (vi):
Ref (ini) ≧ 300 nm (i)
Ha (ini) ≦ 1% (ii)
(Ref (ini) −Ref (NaOH)) / Ref (ini) ≦ 0.05 (iii)
(Ref (ini) −Ref (EtOH)) / Ref (ini) ≦ 0.05 (iv)
(Ha (NaOH) -Ha (ini)) / Ha (ini) ≦ 0.05 (v)
(Ha (EtOH) −Ha (ini)) / Ha (ini) ≦ 0.05 (vi)
However,
Ref (ini) is the selective reflection bandwidth of the reflective layer;
Ha (ini) is the haze of the reflective layer;
Ref (NaOH) is the selective reflection bandwidth of the reflective layer after immersing the reflective layer in a 5 wt% aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours,
Ha (NaOH) is the haze of the reflective layer after immersing the reflective layer in a 5 wt% aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours,
Ref (EtOH) is the selective reflection bandwidth of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours,
Ha (EtOH) is the haze of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours.
Laminate for operation panel.
[2] The laminate according to [1], wherein the reflective layer is a single layer and has a thickness of 7 μm or less.
[3] The laminate according to [1] or [2], wherein the transparent member has a light transmittance of 70% or more at a wavelength of 350 nm.
[4] The laminate according to any one of [1] to [3], further including a temporary support provided on the second surface of the reflective layer.
[5] An operation panel including a display unit and the laminate according to any one of [1] to [3], wherein the laminate is provided on the display unit via an adhesive layer (B).
[6] The operation panel according to [5], wherein the second surface of the transparent member faces the display unit.
[7] The operation panel according to [5], wherein the second surface of the reflective layer faces the display unit.
[8] A home appliance including the operation panel according to any one of [5] to [7].
[9] A method for producing a laminate according to any one of [1] to [3],
Forming a reflective layer on the temporary support (I),
Including a step (II) of bonding the transparent member and the reflective layer through an adhesive layer (A), and a step (III) of peeling the temporary support from the reflective layer.
A manufacturing method of a layered product.

  According to the laminate and the method for producing a laminate of the present invention, a laminate having excellent design properties and chemical resistance can be provided.

FIG. 1 is a cross-sectional view schematically showing one embodiment of the laminate of the present invention. FIG. 2 is a cross-sectional view schematically showing another embodiment of the laminate of the present invention. FIG. 3 is a cross-sectional view schematically showing one embodiment of the operation panel of the present invention. FIG. 4 is a cross-sectional view schematically showing another embodiment of the operation panel of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and exemplifications, and can be implemented with any modifications without departing from the scope of the claims of the present invention and the equivalents thereof. In the following description, the same elements may be denoted by the same reference numerals and description thereof may be omitted.
In the following description, the “composition” may be composed of only one kind of substance or may contain two or more kinds of substances.
In the following description, the adhesive is not only a narrowly-defined adhesive (a so-called hot melt type adhesive having a shear storage elastic modulus at 23 ° C. of 1 to 500 MPa and not exhibiting tackiness at room temperature), and 23 ° C. Also included are adhesives having a shear storage modulus of less than 1 MPa.

[1. Overview of laminate for operation panel]
The operation panel laminate of the present invention includes a transparent member, a reflective layer, and an adhesive layer (A). FIG. 1 is a cross-sectional view schematically showing one embodiment of the laminate of the present invention. The laminate 100 includes a transparent member 10, a reflective layer 20, and an adhesive layer 30 as an adhesive layer (A). The adhesive layer 30 is in contact with the surface S11 of the transparent member 10. The surface S <b> 11 is a surface that is not exposed on the surface of the multilayer body 100 among the two main surfaces of the transparent member 10, the surface S <b> 11 and the surface S <b> 12. The adhesive layer 30 is in contact with the surface S <b> 21 of the reflective layer 20. The surface S <b> 21 is a surface that is not exposed on the surface of the multilayer body 100 among the two main surfaces of the reflective layer 20, the surface S <b> 21 and the surface S <b> 22.

[1.1. Reflective layer]
The reflective layer is made of a cured product of the cholesteric liquid crystal composition and satisfies the formulas (i) to (vi).

[1.1.2. Cured product of cholesteric liquid crystal composition]
The cholesteric liquid crystal composition includes a liquid crystal composition, and preferably includes a photopolymerizable liquid crystal compound.
The cholesteric liquid crystal composition refers to a composition that can exhibit a liquid crystal phase having a cholesteric regularity (cholesteric liquid crystal phase) when the liquid crystal compound contained in the cholesteric liquid crystal composition is aligned.
A reflective layer exhibiting cholesteric regularity can be obtained by curing the cholesteric liquid crystal composition while the liquid crystal compound exhibits cholesteric regularity. Cholesteric regularity means that the molecular axes are aligned in a certain direction on one plane, but the direction of the molecular axis deviates slightly at the next plane that overlaps it, and the angle shifts further at the next plane. In this way, the structure is such that the molecular axes in the planes are displaced (twisted) as they sequentially pass through the overlapping planes. Thus, the structure in which the direction of the molecular axis is twisted becomes an optically chiral structure.

A cured product of a cholesteric liquid crystal composition exhibiting cholesteric regularity usually has a circularly polarized light separation function. That is, it has a property of transmitting one circularly polarized light of right circularly polarized light and left circularly polarized light and reflecting a part or all of the other circularly polarized light.
Therefore, by forming the reflective layer with a cured product of the cholesteric liquid crystal composition, it is possible to obtain a laminated body having a metallic appearance with little color, that is, a silver appearance and light transmittance.

As the photopolymerizable liquid crystal compound that can be contained in the cholesteric liquid crystal composition, a photopolymerizable liquid crystal compound that can be polymerized by irradiation with active energy rays can be arbitrarily used. As the active energy ray, any energy ray capable of proceeding the polymerization reaction of the photopolymerizable liquid crystal compound from a wide range of energy rays such as visible light, ultraviolet ray, and infrared ray can be adopted. Ionizing radiation is preferred. Among these, as the photopolymerizable liquid crystal compound suitably used for the cholesteric liquid crystal composition, a rod-like liquid crystal compound having two or more reactive groups in one molecule is preferable, and a compound represented by the formula (1) is particularly preferable. .
R ³ -C ³ -D ³ -C ⁵ -M C ⁶ -D ⁴ -C ⁴ -R ⁴ (1)

In formula (1), R ³ and R ⁴ are reactive groups, each independently (meth) acrylic group, (thio) epoxy group, oxetane group, thietanyl group, aziridinyl group, pyrrole group, vinyl group. , An allyl group, a fumarate group, a cinnamoyl group, an oxazoline group, a mercapto group, an iso (thio) cyanate group, an amino group, a hydroxyl group, a carboxyl group, and an alkoxysilyl group. By having these reactive groups, a reflective layer having high mechanical strength can be obtained when the liquid crystal composition is cured.

In Formula (1), D ³ and D ⁴ are each independently a single bond, a linear or branched alkyl group having 1 to 20 carbon atoms, and 1 to 20 carbon atoms. Represents a group selected from the group consisting of a linear or branched alkylene oxide group.

In Formula (1), C ^{3 to} C ⁶ are each independently a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH _{2. -, - OCH 2 -, -} CH = N-N = CH -, - NHCO -, - O- (C = O) -O -, - CH 2 - (C = O) -O-, and -CH ₂ Represents a group selected from the group consisting of O— (C═O) —.

In the formula (1), M represents a mesogenic group. Specifically, M is an azomethine group, azoxy group, phenyl group, biphenyl group, terphenyl group, naphthalene group, anthracene group, benzoic acid ester group, cyclohexanecarboxyl group, which may be unsubstituted or substituted. 2 to 4 identical or different from each other selected from the group consisting of acid phenyl esters, cyanophenyl cyclohexanes, cyano substituted phenyl pyrimidines, alkoxy substituted phenyl pyrimidines, phenyl dioxanes, tolanes, and alkenyl cyclohexyl benzonitriles pieces of skeleton, -O -, - S -, - S-S -, - CO -, - CS -, - OCO -, - CH 2 -, - OCH 2 -, - CH = N-N = CH- , -NHCO -, - O- (C = O) -O -, - CH 2 - (C = O) -O-, and _{-CH 2 O- (C = O)} - Of representing the combined group by a linking group.

Examples of the substituent that the mesogenic group M may have include, for example, a halogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, a cyano group, a nitro group, —O—R ⁵ , — O—C (═O) —R ⁵ , —C (═O) —O—R ⁵ , —O—C (═O) —O—R ⁵ , —NR ⁵ —C (═O) —R ⁵ , -C (= O) -NR < ⁵ > R < ⁷ > or -O-C (= O) -NR < ⁵ > R < ⁷ > is mentioned. Here, R ⁵ and R ⁷ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. When R ⁵ and R ⁷ are alkyl groups, the alkyl groups include —O—, —S—, —O—C (═O) —, —C (═O) —O—, —O—C. (═O) —O—, —NR ⁶ —C (═O) —, —C (═O) —NR ⁶ —, —NR ⁶ —, or —C (═O) — may be present. (However, the case where two or more of -O- and -S- are adjacent to each other is excluded). Here, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  Examples of the substituent in the “optionally substituted alkyl group having 1 to 10 carbon atoms” include, for example, a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and a carbon atom number of 1 to 6 alkoxy groups, alkoxyalkoxy groups having 2 to 8 carbon atoms, alkoxyalkoxyalkoxy groups having 3 to 15 carbon atoms, alkoxycarbonyl groups having 2 to 7 carbon atoms, and 2 carbon atoms A 7 to 7 alkylcarbonyloxy group, an alkoxycarbonyloxy group having 2 to 7 carbon atoms, and the like.

The rod-like liquid crystal compound preferably has an asymmetric structure. Here, the asymmetric structure is a structure in which R ³ -C ³ -D ³ -C ⁵ -and -C ⁶ -D ⁴ -C ⁴ -R ⁴ are different from each other in the formula (1) with the mesogenic group M as the center. Say. By using a rod-shaped liquid crystal compound having an asymmetric structure, alignment uniformity can be further improved.
The refractive index anisotropy Δn of the rod-like liquid crystal compound is preferably 0.18 or more, more preferably 0.22 or more. When a rod-like liquid crystal compound having a refractive index anisotropy Δn of 0.30 or more is used, the absorption edge on the long wavelength side of the ultraviolet absorption spectrum may extend to the visible range, but the absorption edge of the spectrum extends to the visible range. However, it can be used as long as the desired optical performance is not adversely affected. By using such a rod-like liquid crystal compound having a high refractive index anisotropy Δn, a reflective layer made of a cured product of a cholesteric liquid crystal composition having high optical performance (for example, selective reflection performance of circularly polarized light) is obtained. Can do.
The refractive index anisotropy Δn is preferably high. By using a liquid crystal compound having a high refractive index anisotropy Δn, the refractive index anisotropy Δn of the liquid crystal composition containing the liquid crystal compound can be improved, and the wavelength range in which circularly polarized light can be reflected is wide, and a thinner cholesteric liquid crystal A reflective layer made of a cured product of the composition can be produced. Here, the refractive index anisotropy Δn can be measured by the Senarmon method.

  Preferable specific examples of the rod-like liquid crystal compound include the following compounds (B1) to (B9). Moreover, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

When the liquid crystal composition includes the rod-shaped liquid crystal compound described above, the liquid crystal composition preferably includes a compound represented by the formula (2) in combination with the rod-shaped liquid crystal compound.
R ¹ -A ¹ -BA ² -R ² (2)

In Formula (2), R ¹ and R ² are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, or a straight chain having 1 to 20 carbon atoms. Or a branched alkylene oxide group, a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, an amino group, which may be bonded with an arbitrary bonding group, And a group selected from the group consisting of a cyano group.

  The alkyl group and alkylene oxide group may be unsubstituted or substituted with one or more halogen atoms. Furthermore, the halogen atom, hydroxyl group, carboxyl group, (meth) acryl group, epoxy group, mercapto group, isocyanate group, amino group, and cyano group are alkyl groups having 1 to 2 carbon atoms, and alkylene oxide. It may be bonded to a group.

Preferred examples of R ¹ and R ² include a halogen atom, a hydroxyl group, a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, an amino group, and a cyano group.

In addition, at least one of R ¹ and R ² is preferably a reactive group. By having a reactive group as at least one of R ¹ and R ^2, the compound represented by the formula (2) is fixed in the reflective layer at the time of curing, and a stronger layer can be formed. Here, examples of the reactive group include a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, and an amino group.

In the formula (2), A ¹ and A ² are each independently 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenylene group, 4,4′-biphenylene group, 4 , 4′-bicyclohexylene group and a group selected from the group consisting of 2,6-naphthylene group. The 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenylene group, 4,4′-biphenylene group, 4,4′-bicyclohexylene group, and 2,6-naphthylene group Is unsubstituted or substituted with one or more substituents such as a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkyl group having 1 to 10 carbon atoms, and a halogenated alkyl group. It may be. In each of A ¹ and A ² , when two or more substituents are present, they may be the same or different.

Particularly preferred as A ¹ and A ² are groups selected from the group consisting of 1,4-phenylene group, 4,4′-biphenylene group, and 2,6-naphthylene group. These aromatic ring skeletons are relatively rigid as compared with the alicyclic skeletons, have high affinity with the mesogen of the rod-like liquid crystal compound, and higher alignment uniformity.

In the formula (2), B represents a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH ₂ —, —OCH ₂ —, —CH. = N-N = CH -, - NHCO -, - O- (C = O) -O -, - CH 2 - (C = O) -O-, and _{-CH 2 O- (C = O)} - from the Selected from the group consisting of
Particularly preferable examples of B include a single bond, —O— (C═O) —, and —CH═N—N═CH—.

  Specific examples of particularly preferable compounds represented by the formula (2) include the following compounds (A1) to (A9). One of these may be used alone, or two or more of these may be used in combination at any ratio.

  In the compound (A3), “*” represents a chiral center.

The weight ratio represented by (total weight of compounds represented by formula (2)) / (total weight of rod-like liquid crystal compound) is preferably 0.05 or more, more preferably 0.1 or more, and particularly preferably 0.8. It is 15 or more, preferably 1 or less, more preferably 0.65 or less, and particularly preferably 0.45 or less. By setting the weight ratio to be equal to or higher than the lower limit, alignment uniformity can be enhanced in the liquid crystal composition layer. Further, by setting the upper limit value or less, the alignment uniformity can be increased. In addition, the stability of the liquid crystal phase of the liquid crystal composition can be increased.
Further, since the refractive index anisotropy Δn of the liquid crystal composition can be increased, a reflective layer having desired optical performance (for example, selective reflection performance of circularly polarized light) can be stably obtained.
Here, the total weight indicates the weight when one type is used, and indicates the total weight when two or more types are used.
When the compound represented by formula (2) and the rod-like liquid crystal compound are used in combination, the molecular weight of the compound represented by formula (2) is preferably less than 600, and the molecular weight of the rod-like liquid crystal compound is 600 or more. It is preferable that Thereby, since the compound represented by Formula (2) can enter into the gaps between the rod-like liquid crystal compounds having a molecular weight larger than that, the alignment uniformity can be improved.

The liquid crystal composition may further contain a chiral agent. Usually, the twist direction in the cholesteric liquid crystal phase can be selected depending on the type and structure of the chiral agent used. A conventionally well-known agent can be used suitably as a chiral agent. Specific examples of the chiral agent include JP-A-2005-289881, JP-A-2004-115414, JP-A-2003-66214, JP-A-2003-313187, JP-A-2003-342219, JP-A-2003-342219. Examples thereof include those described in 2000-290315, JP-A-6-072962, U.S. Pat. No. 6,468,444, WO 98/00428, JP-A 2007-176870, and the like. A commercially available product can also be used as the chiral agent, and for example, it can be obtained as LC756 of BASF Corporation Paliocolor. Moreover, a chiral agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
The chiral agent preferably has a helical twisting power (HTP) of 9.0 or more at 25 ° C. More preferably, HTP can be 30.0 or more. On the other hand, the upper limit of HTP is not particularly limited, but can be 200 or less.
Here, HTP is the following formula (3):
HTP = 1 / (P × 0.01C) (3)
Is required. In the formula, C represents a content ratio (% by weight) of a chiral agent in a liquid crystal composition containing a polymerization initiator and a photopolymerizable liquid crystal compound during polymerization, and P represents a helical structure of the liquid crystal compound in the liquid crystal composition. Represents the pitch length (nm). Here, the pitch length P of the liquid crystal compound is expressed by a relational expression of λ = n × P from the selective reflection center wavelength λ and the average refractive index n of the liquid crystal layer obtained by applying the liquid crystal composition on the base film. It can be obtained by actual measurement of an electron micrograph. That is, since the selective reflection bandwidth Δλ is expressed by Δλ = Δn × P, the selective reflection bandwidth can be widened by using a liquid crystal compound having a large refractive index anisotropy Δn. By using a chiral agent having a high HTP, the pitch of the helical structure can be reduced and the twist can be increased without impairing the liquid crystal properties of the liquid crystal compound. A representative example of a compound having a large HTP is disclosed in British Patent No. 2298202.
The amount of the chiral agent can be arbitrarily set within a range not deteriorating the desired optical performance. The specific amount of the chiral agent is usually 1% by weight to 60% by weight in the liquid crystal composition.

The liquid crystal composition may further contain a crosslinking agent. The cross-linking agent increases the cross-linking density of the reflective layer by, for example, reacting when the layer of the liquid crystal composition is cured, promoting the reaction by heat treatment after curing, or allowing the reaction to proceed spontaneously due to moisture. Can do. As a crosslinking agent, what can react with an ultraviolet-ray, a heat | fever, humidity, etc. can be used, for example. For example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2- (2-vinyloxyethoxy) ethyl acrylate, etc. Functional acrylate compounds; epoxy compounds such as glycidyl (meth) acrylate, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether; 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate ], 4-4-bis (ethyleneiminocarbonylamino) diphenylmethane, trimethylolpropane-tri-β-aziridinylpropionate Lysine compounds; Isocyanurate type isocyanates derived from hexamethylene diisocyanate, hexamethylene diisocyanate, isocyanurate type isocyanates, biuret type isocyanates, adduct type isocyanates; polyoxazoline compounds having an oxazoline group in the side chain; vinyltrimethoxysilane, N- ( 2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, N- (1,3- And alkoxysilane compounds such as dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine. Moreover, a crosslinking agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Furthermore, you may use a well-known catalyst according to the reactivity of a crosslinking agent. By using a catalyst, productivity can be improved in addition to improvement in film strength and durability of the reflective layer.
The amount of the crosslinking agent is preferably such that the amount of the crosslinking agent in the reflective layer obtained by curing the film of the liquid crystal composition is 0.1% by weight to 15% by weight. By setting the amount of the crosslinking agent to be not less than the lower limit of the above range, the crosslinking density can be effectively increased. Moreover, the stability of the film | membrane of a liquid-crystal composition can be improved by making it into an upper limit or less.

The liquid crystal composition may further contain a polymerization initiator. As a polymerization initiator, the compound which can generate | occur | produce a radical or an acid by active energy rays, such as an ultraviolet-ray and visible light, can be used, for example. Specific examples of the polymerization initiator include benzoin, benzylmethyl ketal, benzophenone, biacetyl, acetophenone, Michler's ketone, benzyl, benzylisobutyl ether, tetramethylthiuram mono (di) sulfide, 2,2-azobisisobutyronitrile, 2 , 2-azobis-2,4-dimethylvaleronitrile, benzoyl peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, methylbenzoyl formate 2,2-diethoxyacetophenone, β-ionone, β-bromostyrene, diazoaminobenzene, α-amylcinnac aldehyde, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p, p '-Dichlorobenzophenone, p, p'-bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin n-butyl ether, diphenyl sulfide, bis (2,6-methoxybenzoyl) -2,4 4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one , Anthracene benzophenone, α-chloroanthraquinone, diphenyl disulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1-chloromethylnaphthalene, 1,2-octanedione-1- [4- (phenylthio) -2- (o -Benzoyloxime)] and 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) ) [4- (2-Methylpropyl) phenyl] iodonium hexafluoro Osufeto, 3-methyl-2-butynyl tetramethyl hexafluoroantimonate, diphenyl - (p-phenylthiophenyl) sulfonium hexafluoroantimonate, and the like.
Commercially available products can be used as the polymerization initiator. Examples of commercially available products include “Irgacure 379EG”, “Irgacure 184”, “Irgacure 907”, “Irgacure 369”, “Irgacure TPO”, “Igacure TPO”, “ Irgacure OXE01 "and the like.
A polymerization initiator may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Furthermore, you may control sclerosis | hardenability using the tertiary amine compound as a well-known photosensitizer or a polymerization accelerator as needed.
The amount of the polymerization initiator is preferably 0.03% to 7% by weight in the liquid crystal composition. By setting the amount of the polymerization initiator to be not less than the lower limit of the above range, the degree of polymerization can be increased, so that the film strength of the reflective layer can be increased. Moreover, since the alignment of a liquid crystal compound can be made favorable by setting it as an upper limit or less, the liquid crystal phase of a liquid-crystal composition can be stabilized.

The liquid crystal composition may further contain a surfactant. As the surfactant, those which do not easily disturb the orientation are preferable. As such a surfactant, for example, a nonionic surfactant containing a siloxane or a fluorinated alkyl group in the hydrophobic group portion is preferably exemplified. Of these, oligomers having two or more hydrophobic group moieties in one molecule are particularly suitable. Specific examples of these surfactants include PolyFox PF-151N, PF-636, PF-6320, PF-656, PF-6520, PF-3320, PF-651, PF-652 from OMNOVA; Neos FTX-209F, FTX-208G, FTX-204D, and Surflon KH-40, S-420, S-651 from Seimi Chemical Co., etc. can be used. Moreover, surfactant may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.
The amount of the surfactant is preferably such that the amount of the surfactant in the reflective layer obtained by curing the cholesteric liquid crystal composition is 0.05% by weight to 3% by weight. By setting the amount of the surfactant to be equal to or higher than the lower limit of the above range, the alignment regulating force at the air interface can be increased, so that alignment defects can be prevented. Moreover, by making it into the upper limit value or less, it is possible to prevent a decrease in alignment uniformity due to excessive surfactant entering between liquid crystal molecules.

  The liquid crystal composition may further contain an optional component. Examples of optional components include a solvent; a polymerization inhibitor for improving pot life; an antioxidant, an ultraviolet absorber and a light stabilizer for improving durability; and the like. Moreover, these arbitrary components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. The amount of these optional components can be arbitrarily set within a range that does not deteriorate the desired optical performance. The manufacturing method of a liquid crystal composition is not specifically limited, It can manufacture by mixing said each component.

[1.1.3. Formula (i)]
The reflective layer satisfies the following formula (i).
Ref (ini) ≧ 300 nm (i)
Here, Ref (ini) is the selective reflection bandwidth of the reflective layer. The selective reflection bandwidth means a bandwidth having a reflectance of 40% or more in a wavelength range of 350 nm to 850 nm.
When the reflective layer satisfies the formula (i), a laminate having a metallic appearance with little color, that is, a silver appearance can be obtained.
A larger value of Ref (ini) is preferable because a laminate having a silver appearance with less coloring can be obtained.

The selective reflection bandwidth of the reflective layer is preferably 300 nm or more, more preferably 320 nm or more, and usually 450 nm or less.
Further, the maximum wavelength on the long wavelength side at an incident angle of 0 degree at which the reflectance is 40% or more is preferably 700 nm or more, more preferably 730 nm or more.
In addition, the reflective layer may shift in the selective reflection band to the short wavelength side when the incident angle increases, and may appear colored when observed from an oblique direction.

  The selective reflection bandwidth of the reflective layer is determined by measuring the reflection spectrum in the wavelength range of 350 nm to 850 nm using an ultraviolet-visible near-infrared spectrophotometer (eg, “V-570” manufactured by JASCO Corporation). Can do.

[1.1.4. Formula (ii)]
The reflective layer satisfies the following formula (ii).
Ha (ini) ≦ 1% (ii)
Here, Ha (ini) is the haze of the reflective layer. Thereby, when a laminated body is used for an operation panel, it is possible to obtain an operation panel with a clear appearance and a clear display.
The value of Ha (ini) is preferably as small as possible, and is usually 0% or more.

[1.1.5. Formulas (iii) to (vi)]
The reflective layer satisfies the following formulas (iii) to (vi).
(Ref (ini) −Ref (NaOH)) / Ref (ini) ≦ 0.05 (iii)
(Ref (ini) −Ref (EtOH)) / Ref (ini) ≦ 0.05 (iv)
(Ha (NaOH) -Ha (ini)) / Ha (ini) ≦ 0.05 (v)
(Ha (EtOH) −Ha (ini)) / Ha (ini) ≦ 0.05 (vi)

Here, Ref (ini) and Ha (ini) have the same meaning as described above.
Ref (NaOH) is the selective reflection bandwidth of the reflective layer after the reflective layer is immersed in a 5% by weight aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours.
Ha (NaOH) is the haze of the reflective layer after the reflective layer is immersed in a 5% by weight aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours.
Ref (EtOH) is the selective reflection bandwidth of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours.
Ha (EtOH) is the haze of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours.
The details of each immersion condition are based on the conditions described in Japanese Industrial Standard (JIS) K7114.
Since the reflective layer included in the laminate of the present invention satisfies the formulas (iii) to (vi), even when the laminate is used for an operation panel that is often cleaned with an alkaline detergent and ethanol, the appearance of the laminate Is hard to change.

Further, the selective reflection bandwidth of the reflective layer after being immersed in a 5% by weight aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours is preferably 300 nm or more, more preferably 330 nm or more. Usually, it is 450 nm or less.
Furthermore, the selective reflection bandwidth of the reflective layer after immersing the reflective layer in ethanol at 23 ° C. ± 2 ° C. for 24 hours is preferably 300 nm or more, more preferably 330 nm or more, and usually 450 nm or less. .

In the formula (iii), the value of (Ref (ini) −Ref (EtOH)) / Ref (ini) is preferably as small as possible, but is usually 0 or more.
In formula (iv), the value of (Ref (ini) −Ref (EtOH)) / Ref (ini) is preferably as small as possible, but is usually 0 or more.
In the formula (v), the value of (Ha (NaOH) -Ha (ini)) / Ha (ini) is preferably as small as possible, but is usually 0 or more.
In formula (vi), the smaller the value of (Ha (EtOH) −Ha (ini)) / Ha (ini), the better.

[1.1.6. Structure and thickness of reflection layer]
The reflective layer may have a multilayer structure or a single layer structure, but preferably has a single layer structure. Thereby, the manufacturing process of a laminated body can be simplified.
The thickness of the reflective layer is not particularly limited, but is preferably 0.5 μm or more, more preferably 0.7 μm or more, particularly preferably 1 μm or more, preferably 7 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. is there.

[1.2. Transparent member]
The transparent member can be a transparent or translucent member. The transparent member preferably has a transmittance of light having a wavelength of 350 nm of 70% or more. The transmittance of light having a wavelength of 350 nm of the transparent member is preferably as high as possible, but is usually 100% or less.

  The material of the transparent member is not particularly limited, and a known material can be used. The transparent member is usually a resin film. The resin that can be contained in the transparent member contains a polymer and optional components as necessary. Examples of the polymer contained in the resin include chain olefin polymer, cycloolefin polymer, polycarbonate, polyester, polysulfone, polyethersulfone, polystyrene, polyvinyl alcohol, cellulose acetate polymer, polyvinyl chloride, and polymethacrylate. It is done. The resin may contain one kind of polymer or may contain a combination of two or more kinds of polymers.

  Specific examples of the transparent member include a cycloolefin film (eg, Zeon Corporation (registered trademark) “Zeonor Film”, JSR Corporation “ARTON Film”, resin (registered trademark) “Appel” supplied by Mitsui Chemicals, Inc.). Film, resin (registered trademark) “Topas” film supplied by Ticona), polyethylene terephthalate film (eg, “Cosmo Shine (registered trademark) A4100” manufactured by Toyobo), polymethyl methacrylate film (eg, Sumitomo) "Technoloy (registered trademark) S001" manufactured by Kagaku Co., Ltd., "EX001" resin "Acrylite (registered trademark)" supplied by Mitsubishi Rayon Co., Ltd., triacetyl cellulose film (eg, registered trademark of Fuji Film Co., Ltd.) TAC-TD80U) and the like.

  Although the thickness of a transparent member is not specifically limited, Preferably it is 20 micrometers or more, More preferably, it is 40 micrometers or more, Preferably it is 3000 micrometers or less, More preferably, it is 2000 micrometers or less.

[1.3. Adhesive layer (A)]
The adhesive layer (A) can be a layer having a function of bonding the reflective layer and the transparent member. The adhesive layer (A) is usually composed of an adhesive or a cured product of the adhesive.

  Examples of the adhesive include those based on various polymers. Examples of such base polymers include, for example, acrylic, urethane, polyester, polyamide, polyvinyl ether, polyvinyl alcohol, polyvinyl acetal, polyvinyl formal, hydroxyethyl cellulose, hydroxypropyl cellulose, ethylene-vinyl acetate, ethylene-acrylic acid. Examples include ester-based, ethylene-vinyl chloride-based, synthetic rubber-based polymers such as styrene-butadiene-styrene, epoxy-based polymers, and silicone-based polymers. The adhesive may contain any component such as a polymerization initiator, a curing agent, an ultraviolet absorber, a colorant, and an antistatic agent in combination with the base polymer.

Specific examples of the base polymer include urethane acrylate (eg, “UV-7000B” manufactured by Nippon Synthetic Chemical), 2-hydroxy-3-phenoxypropyl acrylate (eg, “DA141” manufactured by Nagase Chemitech), and 4-hydroxybutyl acrylate. Is mentioned.
Specific examples of the polymerization initiator include “IRGACURE (registered trademark) 651” manufactured by Ciba Specialty Chemicals.
One type of adhesive may be used alone, or a combination of two or more types may be used.
A commercially available product (eg, “Aronix (registered trademark) LCR0631” manufactured by Toa Gosei Co., Ltd.) can be used as the adhesive.

  The thickness of the adhesive layer (A) is not particularly limited, but is preferably 0.5 μm or more, more preferably 1.0 μm or more, preferably 30 μm or less, more preferably 20 μm or less.

[1.4. Any layer]
The laminated body of this invention may contain arbitrary layers other than a transparent member, a reflection layer, and the contact bonding layer (A).
As an arbitrary layer, the temporary support body which provides a reflection layer is mentioned, for example.
FIG. 2 is a cross-sectional view schematically showing another embodiment of the laminate of the present invention.
The laminated body 101 includes a transparent member 10, a reflective layer 20, an adhesive layer 30 as an adhesive layer (A), and a temporary support 40. The temporary support 40 is provided on the surface S22 so as to be in contact with the surface S22 of the reflective layer 20.

The material for the temporary support is not particularly limited. The temporary support is preferably transparent or translucent, and more preferably the temporary support has a light transmittance of 70% or more at a wavelength of 350 nm. Thereby, the reflective layer can be formed by curing the liquid crystal composition applied to the temporary support by irradiating light from the temporary support side.
The temporary support is usually a resin film. The temporary support may be made of the same material as the transparent member or may be made of a material different from the transparent member, but is preferably made of the same material as the transparent member.
Examples of the material and specific examples of the temporary support include the same examples and specific examples given as the material of the transparent member.
The temporary support preferably has a low adhesion to the reflective layer, and is preferably a film containing polyester, from the viewpoint of easily peeling the temporary support from the reflective layer.

  The thickness of the temporary support is not particularly limited, but is preferably 30 μm or more, more preferably 60 μm or more, and preferably 300 μm or less, more preferably from the viewpoints of handleability during production, material cost, thickness reduction and weight reduction. Is 200 μm or less.

Of the main surface of the temporary support, the surface in contact with the reflective layer preferably has an orientation regulating force.
The alignment regulating force of a certain surface refers to the property of the surface that can align the liquid crystal compound in the liquid crystal composition applied to the surface. Since the surface of the temporary support has an alignment regulating force, the alignment of the liquid crystal compound in the liquid crystal composition coated on the surface can be promoted, so that a reflective layer having a desired optical function can be easily obtained. Can do.
The orientation regulating force can be generated by any treatment. Examples of the treatment for generating the alignment regulating force on the surface of the temporary support include rubbing treatment, stretching treatment, alignment film formation treatment, photo-alignment treatment, ion beam irradiation treatment, and vapor deposition film formation treatment.
The main surface of the temporary support may be subjected to a treatment such as an easy adhesion treatment.

  Other examples of the optional layer include a hard coat layer, an antireflection layer, a mat layer, an easy adhesion layer, and an antifouling layer for protecting the reflective layer from mechanical damage.

[2. Manufacturing method of laminate]
The manufacturing method of the laminated body of this invention is not specifically limited, It can manufacture using a well-known method.
The laminate of the present invention can be produced, for example, by a production method including the following steps in this order:
A step (I) of forming a reflective layer on the temporary support; and a step (II) of bonding the transparent member and the reflective layer through the adhesive layer (A).
The production process of the laminate of the present invention preferably further includes the following steps after step (II):
Step (III) of peeling the temporary support from the reflective layer.
Hereinafter, each step will be described.

[2.1. Step (I)]
In step (I), a reflective layer is formed on the temporary support. The temporary support used in the step (I) usually has one of two main surfaces having an orientation regulating force, and a reflective layer is formed on the surface having the orientation regulating force.
The method for forming the reflective layer is not particularly limited, but usually, the cholesteric liquid crystal composition is first applied to the surface of the temporary support having an alignment regulating force by a coating method to form an uncured cholesteric liquid crystal composition layer.
Specific examples of the coating method include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, and a bar coating method.

  Thereafter, if necessary, an uncured cholesteric liquid crystal composition layer is subjected to an alignment treatment. The alignment treatment can be performed, for example, by heating the cholesteric liquid crystal composition layer at a temperature of 50 ° C. to 150 ° C. for 0.5 minutes to 10 minutes.

Thereafter, the layer of the cholesteric liquid crystal composition is usually cured to form a reflective layer made of a cured product of the cholesteric liquid crystal composition.
The conditions for curing are not particularly limited, and the conditions for curing the cholesteric liquid crystal composition can be arbitrarily selected. For example, when the cholesteric liquid crystal composition contains a photopolymerizable liquid crystal compound, the layer of the cholesteric liquid crystal composition can be cured by irradiating the layer of the cholesteric liquid crystal composition with ultraviolet rays.
The curing process can be performed, for example, by a combination of one or more light irradiations and a heating process. The heating conditions are, for example, usually 40 ° C. or higher, preferably 50 ° C. or higher, and usually 200 ° C. or lower, preferably 140 ° C. or lower, usually 1 second or longer, preferably 5 seconds or longer, and usually 3 minutes. Hereinafter, the time may be preferably 120 seconds or less. Moreover, the light used for light irradiation includes not only visible light but also ultraviolet rays and other electromagnetic waves. Light irradiation can be performed by, for example, irradiating light having a wavelength of 200 nm to 500 nm for 0.01 second to 3 minutes. At this time, the energy of light irradiated, for ^example, may be a ^{0.01mJ / cm 2 ~50mJ / cm 2} . By repeating 0.01mJ ^/ cm ² ~50mJ / cm 2 of weak ultraviolet irradiation and heating Metropolitan several times alternately, the size of the pitch of the helical structure continuously largely changed, a wide circle of reflection band A reflective layer having a polarization separation function can be obtained. Further, after the extension of the reflection band by weak ultraviolet irradiation, or the like described ^above was irradiated with a relatively strong ultraviolet such ^{50mJ / cm 2 ~10,000mJ / cm 2} , by completely polymerizing a liquid crystal compound, the machine A reflective layer with high target strength can be obtained. The expansion of the reflection band and the irradiation with strong ultraviolet rays may be performed under air. Part or all of the steps may be performed in an atmosphere in which the oxygen concentration is controlled (for example, in a nitrogen atmosphere).
Irradiation of the ultraviolet ray to the layer of the cholesteric liquid crystal composition may be performed indirectly through a temporary support, or may be directly performed on the layer of the cholesteric liquid crystal composition.

[2.2. Step (II)]
In step (II), the transparent member and the reflective layer are bonded via the adhesive layer (A).
The method of pasting is not particularly limited, but usually, by applying an adhesive to the transparent member or the reflective layer, the transparent member and the reflective layer are superimposed, and if necessary, by performing a curing treatment such as ultraviolet irradiation, The transparent member and the reflective layer can be bonded via the adhesive layer (A).
The adhesive is preferably irradiated with ultraviolet rays through a transparent member.

[2.3. Step (III)]
In step (III), the temporary support is peeled from the reflective layer. By peeling the temporary support from the reflective layer, a laminate not including the temporary support can be obtained.

[2.4. Other optional steps]
The manufacturing method of a laminated body may contain arbitrary processes in addition to the said process. As such an optional step, for example, a step of applying an orientation regulating force to the temporary support, such as a step of rubbing the temporary support before forming the reflective layer on the temporary support, Examples include a step of subjecting the temporary support to surface treatment such as corona discharge treatment before forming the reflective layer, and a step of cutting the laminate to obtain a desired size.

[3. control panel]
Since the laminate of the present invention has a metallic appearance with little color and can withstand the cleaning of alkaline detergent and ethanol, home appliances (eg, refrigerators, washing machines, vacuum cleaners, IH cooking heaters, rice cookers, etc.) Suitable for use on the operation panel.
The operation panel of the present invention includes a display unit and the laminate. In the operation panel of the present invention, preferably, the laminate is provided on the display unit via an adhesive layer (B).

FIG. 3 is a cross-sectional view schematically showing one embodiment of the operation panel of the present invention.
The operation panel 201 includes the display unit 60, the adhesive layer 50 as the adhesive layer (B), the transparent member 10, the adhesive layer 30 as the adhesive layer (A), and the reflective layer 20 in this order. The adhesive layer 50 is in contact with the surface S12 of the transparent member 10. The transparent member 10 and the display unit 60 are bonded via the adhesive layer 50 so that the surface S12 of the transparent member 10 faces the display unit 60.

FIG. 4 is a cross-sectional view schematically showing another embodiment of the operation panel of the present invention.
The operation panel 202 includes a display unit 60, an adhesive layer 50 as an adhesive layer (B), a reflective layer 20, an adhesive layer 30 as an adhesive layer (A), and the transparent member 10 in this order. The adhesive layer 50 is in contact with the surface S22 of the reflective layer 20. The reflective layer 20 and the display unit 60 are bonded via the adhesive layer 50 so that the surface S22 of the reflective layer 20 faces the display unit.

  The display unit 60 is a portion on which display (for example, an operation icon) for operation of home appliances is performed. The operation panel of the present invention may include elements such as electrodes, switches, display elements such as liquid crystal display elements, and wirings in addition to the display unit.

The adhesive layer (B) can be a layer having a function of bonding the transparent member and the display unit. The adhesive layer (B) is usually composed of an adhesive or a cured product of the adhesive.
As an example of an adhesive agent, the adhesive agent similar to the adhesive agent illustrated in description of an adhesive layer (A) is mentioned.

  The thickness of the adhesive layer (B) is not particularly limited, but is preferably 0.5 μm or more, more preferably 1.0 μm or more, preferably 30 μm or less, more preferably 20 μm or less.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and the equivalents thereof.
In the following description, “%” and “parts” representing amounts are based on weight unless otherwise specified. Further, the operations described below were performed in a normal temperature and pressure atmosphere unless otherwise specified.

[Evaluation method]

(Chemical resistance test: alkali resistance test and alcohol resistance test)
The film to be tested was subjected to a chemical resistance test in accordance with JIS K7114 "Testing method for determining the effect of immersion in plastic-liquid chemicals". Specifically, the test was performed as follows.
A test piece of A4 size was cut out from the roll film to be tested. This test piece was immersed in a chemical solution maintained at 23 ° C. ± 2 ° C. for 24 hours. Thereafter, the test piece was sufficiently washed with pure water and dried.
About the test piece after drying, the haze and the selective reflection bandwidth were measured by the following method.
In the alkali resistance test, a 5% NaOH aqueous solution was used as a chemical solution.
In the alcohol resistance test, ethyl alcohol was used as a chemical solution.

(Haze)
About the film of evaluation object, haze was measured with the haze meter (Nippon Denshoku Industries Co., Ltd. "NDH5000"). Further, the haze Ha (ini), the haze Ha (NaOH) obtained by measuring the reflective layer before the chemical resistance test, the reflective layer after the alkali resistance test, and the reflective layer after the alcohol resistance test, and From the haze Ha (EtOH), the change rate of the haze was determined by the following formula.
[Change rate of haze in alkali resistance test] =
(Ha (NaOH) -Ha (ini)) / Ha (ini)
[Change rate of haze in alcohol resistance test] =
(Ha (EtOH) -Ha (ini)) / Ha (ini)
In order to measure the haze value of the reflective layer, a laminate including a temporary support and a reflective layer was used.

(Light transmittance)
About the transparent member, the transmittance | permeability of the light which is wavelength 350nm was measured using the ultraviolet visible near-infrared spectrophotometer ("(trade name) V7200" by JASCO Corporation).

(Selective reflection band center wavelength and selective reflection bandwidth)
About the film of evaluation object, the reflection spectrum was measured in the wavelength range of 350 nm-850 nm using the ultraviolet visible near infrared spectrophotometer ("V-570" by JASCO Corporation). From the reflection spectrum, the selective reflection bandwidth having a reflectance of 40% or more and the center wavelength of the selective reflection bandwidth were obtained. The selective reflection bandwidth Ref (ini) and the selective reflection bandwidth obtained by measuring the reflective layer before the chemical resistance test, the reflective layer after the alkali resistance test, and the reflective layer after the alcohol resistance test. From the Ref (NaOH) and the selective reflection bandwidth Ref (EtOH), the change rate of the selective reflection bandwidth was obtained by the following equation.
[Change rate of selective reflection bandwidth in alkali resistance test] =
(Ref (ini) -Ref (NaOH)) / Ref (ini)
[Change rate of selective reflection bandwidth in alcohol resistance test] =
(Ref (ini) -Ref (EtOH)) / Ref (ini)
Since the reflection from the temporary support is negligible, a laminate including the temporary support and the reflective layer is used to measure the selective reflection bandwidth of the reflective layer and the center wavelength of the selective reflection bandwidth. It was.

(Appearance evaluation of laminate)
When the display device having the laminate to be evaluated is not displayed (power is off), the metal glossiness of the surface of the laminate is visually evaluated from the front and obliquely, and the display device is displayed. In the state where the power is on (power-on state), the state of the surface of the laminate (presence of unevenness) was visually evaluated from the front and oblique directions. The evaluation criteria are as follows. The larger the evaluation number, the better the evaluation. The silver metallic tone means a metallic tone with little coloration.

4: Silver metallic tone with no unevenness.
3: Although it is a silver metallic tone, there is unevenness.
2: Although it is not a silver metallic tone, there is no unevenness.
1: Not silvery metallic tone but uneven.

[Example 1]
Cholesteric liquid crystal composition 1 was prepared by mixing the following materials:
Compound 1: 16.1 parts by weight, Compound 2: 4.0 parts by weight, chiral agent (“LC756” manufactured by BASF): 1.25 parts by weight, polymerization initiator (“Irgacure 379EG” manufactured by Ciba Specialty Chemicals): 0.6 parts by weight, surfactant (“FTX-209F” manufactured by Neos): 0.025 parts by weight, cyclopentanone: 78.0 parts by weight.

As a temporary support, a roll of a long polyethylene terephthalate film (“Cosmo Shine (registered trademark) A4100” manufactured by Toyobo Co., Ltd .; thickness 100 μm) was prepared. One side of this temporary support was an easy-adhesion-treated surface that was subjected to an easy-adhesion treatment.
The roll of the temporary support body was attached to the supply part of the film conveying apparatus, and the temporary support body was extended from the roll. And the following operation was performed, conveying a temporary support body in the longitudinal direction.
A rubbing process was performed by rubbing the surface of the transported temporary support opposite to the easy-adhesion-treated surface in the longitudinal direction of the temporary support. Next, the cholesteric liquid crystal composition 1 was filtered on a surface subjected to rubbing treatment with a filter having a pore diameter of 0.45 μm and then applied using a die coater. As a result, an uncured cholesteric liquid crystal composition 1 layer was formed on one side of the temporary support.

  The layer of the obtained cholesteric liquid crystal composition 1 was subjected to alignment treatment at 100 ° C. for 5 minutes. Thereby, in the layer of the cholesteric liquid crystal composition 1, the photopolymerizable liquid crystal compound was aligned and exhibited a cholesteric liquid crystal phase. In addition, the layer of cholesteric liquid crystal composition 1 was dried during the alignment treatment, and the solvent was removed from the layer of cholesteric liquid crystal composition 1.

Thereafter, ultraviolet light (mercury xenon lamp: “EXECURE 3000” manufactured by HOYA) that allows the layer of cholesteric liquid crystal composition 1 to pass through a bandpass filter (350 to 400 nm) from the back side of the temporary support in an air atmosphere at 23 ° C. , 200 W). The irradiation condition is 10 mW / cm ² for 1 second as illuminance with a wavelength of 350 to 400 nm. Then, it hold | maintained at 100 degreeC for 1 minute.
Next, ultraviolet rays (metal halide lamp: “GS” manufactured by YUSASA) were irradiated in a nitrogen atmosphere to the coating film forming surface of the cholesteric liquid crystal composition 1. Irradiation conditions were 5 at 150 mW / cm ² as an illuminance with a wavelength of 350 to 400 nm. Thereby, the layer of the cholesteric liquid crystal composition 1 is cured to become a cured product of the cholesteric liquid crystal composition 1, and the reflective layer (dry thickness 5.1 μm) formed of the temporary support and the cured product of the cholesteric liquid crystal composition 1 is obtained. In order to measure the ultraviolet illuminance, an ultraviolet illuminometer (“UV-M03” manufactured by Oak Seisakusho) was used.

The selective reflection bandwidth of the obtained reflective layer was 320 nm from 455 nm to 775 nm. The haze of the obtained reflective layer was 0.85%.
The obtained laminate 1a was subjected to a chemical resistance test (an alkali resistance test and an alcohol resistance test). The results are shown in Table 1. Here, the laminates subjected to the alkali resistance test and the alcohol resistance test are referred to as a laminate 1b (NaOH) and a laminate 1b (EtOH), respectively.

As a transparent member, a polymethyl methacrylate film (“Technoloy (registered trademark) S001” manufactured by Sumitomo Chemical Co., Ltd., A4 size, thickness 0.125 mm) was prepared. Moreover, the adhesive liquid (adhesive A) which mixed and dissolved the material of the following mixing | blending was prepared.
Formulation of Adhesive A: Urethane acrylate (“UV-7000B” manufactured by Nippon Synthetic Chemical Co., Ltd., 2 to 3 functional groups) 54.5 parts, 36.4 parts of 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Nagase Chemitech “ DA141 ”, viscosity 373 mPa · s), 9.1 parts of 4-hydroxybutyl acrylate, 17.8 parts of methyl ethyl ketone, and 0.9 parts of photopolymerization initiator (“ IRGACURE651 ”manufactured by Ciba Specialty Chemicals)

Adhesive A was applied to a film as a transparent member to a thickness of 5 μm. The application surface of this adhesive A and the reflective layer of the laminate 1a before being subjected to the chemical resistance test are bonded using a laminator, and ultraviolet rays (D bulb, integrated illuminance 1400 mJ / cm ² ) are applied from the transparent member side. The adhesive A was cured by irradiation to produce a laminate 1A1 (before the chemical resistance test). Further, by using the laminate 1b (NaOH) or the laminate 1b (EtOH) after being subjected to the chemical resistance test instead of the laminate 1a, the laminate 1B1 (NaOH) (after the alkali resistance test) or the laminate 1B1 (EtOH) (after alcohol resistance test) was produced. Laminate 1A1, laminate 1B1 (NaOH), and laminate 1B1 (EtOH) have a temporary support, a reflective layer, an adhesive layer (A), and a transparent member in this order.

A display device (22 type, liquid crystal mode, manufactured by SAMSUNG) was prepared assuming an operation panel. An adhesive B (“Aronix LCR0631” manufactured by Toa Gosei Co., Ltd.) was applied to the panel surface (display portion) of this display device. Further, the temporary support was peeled from the laminate 1A to expose the reflective layer. The reflective layer side surface of the laminate 1A from which the temporary support was peeled off was bonded to the panel surface of the display device to which the adhesive B was applied to obtain a display device having the laminate 1A1. The appearance of the laminate 1A1 on the display device was evaluated according to the above evaluation method.
Further, by using the laminated body 1B1 (NaOH) or the laminated body 1B1 (EtOH) instead of the laminated body 1A1, a display device having the laminated body 1B1 (NaOH) or the laminated body 1B1 (EtOH) is obtained, and the display device is used. The outer appearance of the laminate 1B1 (NaOH) or the laminate 1B1 (EtOH) was evaluated according to the evaluation method described above. These results are shown in Table 3. In addition, no coloration was observed even when observed obliquely.

[Example 2]
As the transparent member, “Acrylite (registered trademark) EX001” (thickness: 2 mm) manufactured by Mitsubishi Rayon Co., Ltd. was used, and the ultraviolet ray was irradiated from the temporary support side instead of the ultraviolet ray from the transparent member side. Thus, the laminated body 1A2 was produced from the laminated body 1a, the laminated body 1B2 (NaOH) was produced from the laminated body 1b (NaOH), and the laminated body 1B2 (EtOH) was produced from the laminated body 1b (EtOH). The laminated body 1A2, laminated body 1B2 (NaOH) or laminated body 1B2 (in the same manner as in Example 1 except that the laminated body 1A2, laminated body 1B2 (NaOH), or laminated body 1B2 (EtOH) is used instead of the laminated body 1A. A display device having EtOH) was obtained, and the appearance of the stacked body 1A2, the stacked body 1B2 (NaOH), and the stacked body 1B2 (EtOH) on the display device was evaluated according to the above-described method. These results are shown in Table 1. In addition, no coloration was observed even when observed obliquely.

[Example 3]
A laminated body 1A3 was produced from the laminated body 1a in the same manner as in Example 1 except that “Cosmo Shine (registered trademark) A4100” (thickness 0.1 mm) manufactured by Toyobo Co., Ltd. was used as the transparent member. A laminate 1B3 (NaOH) was produced from (NaOH), and a laminate 1B3 (EtOH) was produced from the laminate 1b (EtOH). A laminated body 1A3, a laminated body 1B3 (NaOH), or a laminated body 1B3 in the same manner as in Example 1 except that the laminated body 1A3, the laminated body 1B3 (NaOH), or the laminated body 1B3 (EtOH) is used instead of the laminated body 1A. A display device having (EtOH) was obtained, and appearances of the stacked body 1A3, the stacked body 1B3 (NaOH), and the stacked body 1B3 (EtOH) on the display device were evaluated according to the above methods. These results are shown in Table 1. In addition, no coloration was observed even when observed obliquely.

[Comparative Example 1]
Cholesteric liquid crystal composition 2 was produced by mixing the following materials:
Compound 3: 15.6 parts by weight, Compound 2: 1.25 parts by weight, chiral agent (“LC756” manufactured by BASF): 1.3 parts by weight, polymerization initiator (“Irgacure 379EG” manufactured by Ciba Specialty Chemicals): 0.5 parts by weight, surfactant (“FTX-209F” manufactured by Neos): 0.03 parts by weight, cyclopentanone: 81.3 parts by weight.

A reflective layer (dry thickness 1.8 μm) made of a temporary support and a cured product of the cholesteric liquid crystal composition 2 in the same manner as in Example 1 except that the cholesteric liquid crystal composition 2 was used instead of the cholesteric liquid crystal composition 1. The laminated body 2a provided with this was obtained. The selective reflection bandwidth of the reflective layer was 180 nm from 480 nm to 660 nm, and the haze was 0.45%.
The obtained laminate 2a was subjected to a chemical resistance test (an alkali resistance test and an alcohol resistance test), and the results are shown in Table 2. Here, the laminates subjected to the alkali resistance test and the alcohol resistance test are referred to as a laminate 2b (NaOH) and a laminate 2b (EtOH), respectively.

  The laminated body 2a is used instead of the laminated body 1a, the laminated body 2b (NaOH) is used instead of the laminated body 1b (NaOH), and the laminated body 2b (EtOH) is used instead of the laminated body 1b (EtOH). In the same manner as in Example 1, a laminated body 2A is produced from the laminated body 2a, a laminated body 2B (NaOH) is produced from the laminated body 2b (NaOH), and a laminated body 2B (EtOH) is produced from the laminated body 2b (EtOH). Manufactured. A laminated body 2A, a laminated body 2B (NaOH) or a laminated body 2B (in the same manner as in Example 1 except that the laminated body 2A, the laminated body 2B (NaOH), or the laminated body 2B (EtOH) is used instead of the laminated body 1A. A display device having EtOH) was obtained, and the appearance of the laminated body 2A, the laminated body 2B (NaOH), and the laminated body 2B (EtOH) on the display device was evaluated according to the above method. These results are shown in Table 3. Moreover, when observed from diagonally, what looked green in front looked blue.

[Comparative Example 2]
As a reflective layer, a commercially available film 3a (“Picasus (registered trademark) GT30” manufactured by Toray Industries, Inc.) was prepared. The commercial film 3a was subjected to a chemical resistance test, and the results are shown in Table 2. The films after being subjected to the alkali resistance test and the alcohol resistance test are referred to as a film 3b (NaOH) and a film 3b (EtOH), respectively. Since the film 3b (NaOH) was significantly damaged, the selective reflection bandwidth and haze could not be measured, and the appearance on the display device could not be evaluated.

  A laminate 3A is produced from the commercially available film 3a in the same manner as in Example 1 except that the commercially available film 3a or the film 3b (EtOH) is used instead of the laminate 1a, and the laminate 3B (EtOH) is produced from the film 3b (EtOH). ) Was manufactured.

A display device similar to that of Example 1 was prepared, and adhesive B was applied to the panel surface of the display device. The surface of the laminate 3A opposite to the transparent member was bonded to the panel surface of the display device to which the adhesive B was applied, to obtain a display device having the laminate 3A. The appearance of the laminate 3A on the display device was evaluated according to the evaluation method described above.
Further, a display device having the laminate 3B (EtOH) is obtained by using the laminate 3B (EtOH) instead of the laminate 3A, and the appearance of the laminate 3B (EtOH) on the display device is evaluated as described above. According to the evaluation. The results are shown in Table 3.

[Comparative Example 3]
As a reflective layer, a commercially available film 4a (3M “Vikuiti-DBEF (registered trademark)” was prepared. The commercially available film 4a was subjected to a chemical resistance test, and the results are shown in Table 2. Alkali resistance test and alcohol resistance test The films after being subjected to the above are referred to as film 4b (NaOH) and film 4b (EtOH), respectively, because the film 4b (NaOH) was significantly damaged, the selective reflection bandwidth and haze could not be measured, Further, the appearance on the display device could not be evaluated.

  A laminate 4A is produced from the commercially available film 4a in the same manner as in Example 1 except that the commercially available film 4a or the film 4b (EtOH) is used instead of the laminate 1a, and the laminate 4B (EtOH) is produced from the film 4b (EtOH). ) Was manufactured.

A display device similar to that of Example 1 was prepared, and adhesive B was applied to the panel surface of the display device. The surface of the laminate 4A opposite to the transparent member was bonded to the panel surface of the display device to which the adhesive B was applied to obtain a display device having the laminate 4A. The appearance of the laminate 4A on the display device was evaluated according to the above evaluation method.
Further, a display device having the laminate 4B (EtOH) is obtained by using the laminate 4B (EtOH) instead of the laminate 4A, and the appearance of the laminate 4B (EtOH) on the display device is evaluated as described above. According to the evaluation. The results are shown in Table 3.

From the above results, the laminates of Examples 1 to 3 including the reflective layer satisfying the formulas (i) to (vi) are excellent in appearance evaluation before and after the alkali resistance test and the alcohol resistance test, and have little color. It has chemical appearance while having a toned appearance. Therefore, it turns out that the laminated body of Examples 1-3 is excellent as an object for operation panels. On the other hand, the laminates of Comparative Examples 1 to 3 that do not include a reflective layer satisfying the formulas (i) to (vi) are inferior in appearance evaluation or chemical resistance as compared with Examples 1 to 3, and are used for an operation panel. You can see that it is inferior.
It can be seen that the laminate of the present invention has excellent design properties (a metallic appearance with little color) and chemical resistance, and is suitable for use in an operation panel of home appliances.

10 transparent member 20 reflective layer 30 adhesive layer (adhesive layer (A))
40 Temporary support 50 Adhesive layer (Adhesive layer (B))
60 Display unit 100, 101 Laminate 201, 202 Operation panel

Claims (9)

A transparent member, a reflective layer, an adhesive layer (A) in contact with the first surface of the transparent member and the first surface of the reflective layer,
The reflective layer is made of a cured product of a cholesteric liquid crystal composition, and the reflective layer satisfies the following formulas (i) to (vi):
Ref (ini) ≧ 300 nm (i)
Ha (ini) ≦ 1% (ii)
(Ref (ini) −Ref (NaOH)) / Ref (ini) ≦ 0.05 (iii)
(Ref (ini) −Ref (EtOH)) / Ref (ini) ≦ 0.05 (iv)
(Ha (NaOH) -Ha (ini)) / Ha (ini) ≦ 0.05 (v)
(Ha (EtOH) −Ha (ini)) / Ha (ini) ≦ 0.05 (vi)
However,
Ref (ini) is the selective reflection bandwidth of the reflective layer;
Ha (ini) is the haze of the reflective layer;
Ref (NaOH) is the selective reflection bandwidth of the reflective layer after immersing the reflective layer in a 5 wt% aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours,
Ha (NaOH) is the haze of the reflective layer after immersing the reflective layer in a 5 wt% aqueous solution of sodium hydroxide at 23 ° C. ± 2 ° C. for 24 hours,
Ref (EtOH) is the selective reflection bandwidth of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours,
Ha (EtOH) is the haze of the reflective layer after the reflective layer is immersed in ethanol at 23 ° C. ± 2 ° C. for 24 hours.
Laminate for operation panel.   The laminate according to claim 1, wherein the reflective layer is a single layer and has a thickness of 7 μm or less.   The laminate according to claim 1 or 2, wherein the transparent member has a light transmittance of 70% or more at a wavelength of 350 nm.   The laminated body of any one of Claims 1-3 which further contains the temporary support body provided in the 2nd surface of the said reflection layer.   An operation panel comprising a display unit and the laminate according to any one of claims 1 to 3, wherein the laminate is provided on the display unit via an adhesive layer (B).   The operation panel according to claim 5, wherein the second surface of the transparent member faces the display unit.   The operation panel according to claim 5, wherein the second surface of the reflective layer faces the display unit.   Household appliances including the operation panel according to any one of claims 5 to 7. It is a manufacturing method of the layered product according to any one of claims 1 to 3,
Forming a reflective layer on the temporary support (I),
Including a step (II) of bonding the transparent member and the reflective layer through an adhesive layer (A), and a step (III) of peeling the temporary support from the reflective layer.
A manufacturing method of a layered product.

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