CN112368143B - Laminate body - Google Patents

Abstract

The present invention provides a stretchable laminate which does not change optical properties and which does not cause appearance defects when stretched. The stretchable laminate is composed of a base layer and a polarizing layer, wherein the moisture content of the base layer is 5.0% or less, and the formula (1) below is satisfied. |E_A－E_T|/|E_A+E_T|≤0.25(1) [In the equation, E_A and E_T represent the tensile elastic modulus in the absorption axis direction and transmission axis direction, respectively].

Description

Laminated body

Technical Field

The present invention relates to a laminate composed of a substrate layer and a polarizing layer.

Background Art

Patent Document 1 proposes a stretchable display device. Patent Document 2 proposes a polarizing plate that can be thermally bent.

Prior art literature

Patent Literature

Patent Document 1: Korean Patent Publication No. 10-2016-0090977

Patent Document 2: Japanese Patent No. 5633228

Summary of the invention

An object of the present invention is to provide a stretchable laminated body in which optical properties such as visibility-corrected single body transmittance and visibility-corrected polarization degree do not significantly change even when stretched, and in which appearance defects such as haze and cracks do not occur.

The present invention provides a laminated body shown below.

A laminate is a stretchable laminate composed of a substrate layer and a polarizing layer, wherein the substrate layer has a moisture content of 5.0% or less and satisfies the following formula (1).

|E _A -E _T |/|E _A +E _T |≦0.25(1)

[Wherein, _EA and _ET represent the tensile elastic modulus in the absorption axis direction and the transmission axis direction, respectively]

The laminate according to [1], wherein the total haze value is 3% or less.

In the laminate according to [1] or [2], the polarizing layer has a thickness of 0.5 μm to 10 μm.

The laminate according to any one of [1] to [3], wherein the polarizing layer is composed of a cured product of a polarizing layer-forming composition containing a polymerizable liquid crystal compound and a dichroic dye.

The laminate according to any one of [1] to [4], wherein the content of the dichroic dye in the polarizing layer is 0.1 to 30 parts by mass based on 100 parts by mass of the polymerizable liquid crystal compound.

The laminate according to any one of [1] to [5], further comprising a pressure-sensitive adhesive layer on the polarizing layer side.

The laminated body according to [6], further comprising a phase difference layer laminated via the adhesive layer.

A display device comprising: an image display element and the laminate according to any one of [1] to [7] bonded together.

Effects of the Invention

According to one embodiment of the present invention, a stretchable laminate can be provided in which optical properties such as visibility correction single body transmittance and visibility correction polarization degree do not significantly change even in a stretched state and in which appearance defects such as haze and cracks do not occur.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view showing a laminated body according to one embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, a laminated body according to one embodiment of the present invention (hereinafter simply referred to as a “laminated body”) will be described with reference to the drawings.

＜Laminated body＞

FIG1 shows a schematic cross-sectional view of a laminate involved in one embodiment of the present invention. The laminate 10 is a stretchable laminate composed of a substrate layer 11 and a polarizing layer 12. Stretchable means that the laminate 10 can be stretched without breaking when it is stretched in at least one of the absorption axis direction and the transmission axis direction. The absorption axis direction refers to the orientation direction of the dichroic pigment and the polymerizable liquid crystal compound when the dichroic pigment and the polymerizable liquid crystal compound described later constituting the polarizing layer 12 are horizontally oriented relative to the substrate layer, and the dichroic pigment showing liquid crystal properties are horizontally oriented relative to the substrate layer. The transmission axis direction refers to the direction horizontal to the substrate layer, and the direction perpendicular to the orientation direction when the dichroic pigment and the polymerizable liquid crystal compound described later constituting the polarizing layer 12 are horizontally oriented relative to the substrate layer, and the dichroic pigment showing liquid crystal properties are horizontally oriented relative to the substrate layer. The orientation state of the polarizing layer can be confirmed by polarizing microscope observation. The laminate sample was inserted between crossed Nicols of a polarizing microscope at about 45° and observed in a light-leaking state. In the case of vertical orientation, a dark field state was observed without light leakage, and in the case of horizontal orientation, a bright field state was observed with light leakage.

The elongation at break in the absorption axis direction and the transmission axis direction of the laminate 10 can be, for example, both 5% or more. When the elongation at break in the absorption axis direction and the transmission axis direction are both 5% or more, there is a tendency to easily obtain sufficient stretchability. The elongation at break in the absorption axis direction and the transmission axis direction of the laminate 10 is preferably 5% to 20%, and more preferably 5% to 15%. When the elongation at break in the absorption axis direction and the transmission axis direction are both 5% to 20%, it is not easy to obtain sufficient stretchability, and there is a tendency that changes in optical properties, poor appearance such as haze and cracks are not easy to occur. The elongation at break in the absorption axis direction and the transmission axis direction is the elongation when the laminate breaks when stretched in the absorption axis direction or the transmission axis direction in a tensile test, and can be measured according to JIS K7161, for example, using UTM (Universal Testing Machine, Autography AG-X, Shimadzu Corporation). The elongation at break can be a value at room temperature (temperature 23°C).

The laminate 10 satisfies the following formula (1) when the tensile elastic moduli in the absorption axis direction and the transmission axis direction are _EA and _ET , respectively.

|E _A -E _T |/|E _A +E _T |≦0.25(1)

When the laminate 10 does not satisfy formula (1) or when the laminate 10 is stretched, the optical properties may change, or it may break easily, or there may be a tendency for poor appearance such as haze and cracks to occur. As a reason for this, it is inferred that by making the laminate have a tensile elastic modulus of a certain degree of isotropy, the optical properties of the laminate can be maintained even when the laminate is stretched. However, the present invention is not limited by this inference. The tensile elastic modulus can be measured based on the measurement method described in the embodiment column described later. The lower limit value of | _EA - _ET |/| _EA + _ET | can be, for example, 0.01. The tensile elastic modulus can adopt a value at room temperature (temperature 23°C).

The laminate 10 can be manufactured by combining the following methods to satisfy the formula (1): for example, adjusting the thickness of the substrate layer 11, the polarizing layer 12, and the orientation layer, selecting the material for the substrate layer, selecting the dichroic pigment for forming the polarizing layer, selecting the polymerizable liquid crystal compound, adjusting their composition ratio, selecting the raw materials used in the composition for forming the orientation layer and adjusting the composition ratio, and adjusting the conditions for forming the polarizing layer and the orientation layer, such as coating conditions, drying conditions, and polymerization conditions. In particular, the tensile modulus of the laminate is related to the tensile modulus of the substrate layer, and therefore, as the substrate layer, it is preferred to use a layer with an elongation of 5% or more.

The laminated body 10 preferably satisfies the following formula (2).

|E _A -E _T |/|E _A +E _T |≤0.20 (2)

The tensile elastic modulus _EA and _ET are, for example, both 1 MPa to 30,000 MPa, preferably 10 MPa to 20,000 MPa, more preferably 50 MPa to 15,000 MPa, and may be 1,000 MPa to 7,000 MPa, or 1,000 MPa to 5,000 MPa. When the tensile elastic modulus _EA and _ET are both 50 MPa to 15,000 MPa, there is a tendency that the laminate 10 is not easily broken even when stretched.

The total haze value of the laminate 10 can be, for example, 3% or less. When the total haze value is 3% or less, it can be suitably used in a display device. The total haze value of the laminate 10 is preferably 2.8% or less, and more preferably 2.5% or less. When the total haze value is 3% or less and the laminate 10 is used in a display device, there is a tendency that visibility is easily improved. The total haze value can be measured based on the method described in the first embodiment column described later. On the other hand, the total haze value is generally 0.1% or more. The total haze value can be measured based on the measurement method described in the first embodiment column described later.

The difference (ΔH) between the total haze value before and after stretching of the laminate 10 may be, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less. In a preferred embodiment, the difference (ΔH) between the total haze value before stretching of the laminate 10 and after stretching by 5% may be, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less. In a more preferred embodiment, the difference (ΔH) between the total haze value before stretching of the laminate 10 and after stretching by 10% may be, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less.

The polarization performance of the laminate 10 can be measured using a spectrophotometer. For example, it can be obtained by using a device in which a bracket with a polarizer is installed on the spectrophotometer, and the transmittance (T1) in the transmission axis direction (the direction perpendicular to the orientation direction of the dichroic pigment) and the transmittance (T2) in the absorption axis direction (the same direction as the orientation direction of the dichroic pigment) in the visible light range of 380nm to 780nm are measured by a double beam method. The polarization performance in the visible light range can be calculated using the following formulas (3) and (4) to calculate the monomer transmittance and polarization degree of each wavelength, and further use the 2-degree field of view (C light source) of JIS Z8701 to perform visibility correction, thereby calculating the visibility-corrected monomer transmittance (Ty) and the visibility-corrected polarization degree (Py).

Single body transmittance (%) = (T1 + T2) / 2 Formula (3)

Polarization degree (%) = (T1-T2)/(T1+T2)×100 Formula (4)

The visibility-corrected single transmittance of the laminate 10 may be, for example, 30% or more, preferably 35% or more, and more preferably 38% or more. On the other hand, the visibility-corrected single transmittance of the laminate 10 is usually 70% or less, preferably 48% or less, and more preferably 46% or less. The visibility-corrected single transmittance can be measured based on the method described in the Examples section below.

The difference (ΔT) between the visibility-corrected monomer transmittance of the laminate 10 before and after being stretched in the absorption axis direction and the transmission axis direction is, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less. In a preferred embodiment, the difference (ΔT) between the visibility-corrected monomer transmittance of the laminate 10 before stretching and after being stretched 5% in the absorption axis direction and the transmission axis direction is, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less. In a more preferred embodiment, the difference (ΔT) between the visibility-corrected monomer transmittance value of the laminate 10 before stretching and after being stretched 10% in the absorption axis direction and the transmission axis direction is, for example, 1.5% or less, preferably 1.2% or less, and more preferably 1% or less.

The visibility-corrected polarization degree of the laminate 10 may be, for example, 80% or more, preferably 85% or more, and more preferably 90% or more. On the other hand, the visibility-corrected polarization degree of the laminate 10 is usually 100% or less, and may be 99.99% or less, or 99.0% or less. The visibility-corrected polarization degree can be measured based on the method described in the Example column described later.

The difference (ΔP) in the visibility correction polarization degree of the stack 10 before and after stretching in the absorption axis direction and the transmission axis direction is, for example, less than 3%, preferably less than 2.5%, and more preferably less than 2%. In a preferred embodiment, the difference (ΔP) in the visibility correction polarization degree of the stack 10 before stretching and after stretching 5% in the absorption axis direction and the transmission axis direction is, for example, less than 3%, preferably less than 2.5%, and more preferably less than 2%. In a more preferred embodiment, the difference (ΔP) in the visibility correction polarization degree of the stack 10 before stretching and after stretching 10% in the absorption axis direction and the transmission axis direction is, for example, less than 3%, preferably less than 2.5%, and more preferably less than 2%.

The thickness of the laminate 10 may be, for example, 25 μm to 1000 μm, preferably 30 μm to 500 μm, and more preferably 35 μm to 100 μm. When the thickness of the laminate 10 is 25 μm to 1000 μm, it tends to be easy to reduce the thickness of the display device.

Hereinafter, each layer constituting the laminated body 10 will be described.

[Base material layer]

The substrate layer 11 may be made of, for example, a resin film, preferably a transparent resin film. The resin film may be a long roll-shaped resin film or a single sheet-shaped resin film. From the viewpoint of continuous production, a long roll-shaped resin film is preferred.

Examples of the resin constituting the resin film include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide; and plastics such as polyphenylene ether. Among them, cyclic olefin resins, cellulose esters, and polyimides are preferred.

As examples of representative commercial products of cyclic olefin resins, "Topas" (registered trademark) (manufactured by Ticona Corporation (individual)), "Arton" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by Zeon Corporation of Japan) and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.) can be cited. Such cyclic olefin resins can be formed into resin films by using known means such as solvent casting and melt extrusion. Commercially available cyclic olefin resin films can also be used. As examples of representative commercial products of cyclic olefin resin films, "ESCENA" (registered trademark), "SCA40" (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), "Zeonor Film" (registered trademark) (manufactured by Optes Corporation) and "Arton Film" (registered trademark) (manufactured by JSR Corporation) can be cited.

Typical commercially available examples of resin films made of cellulose ester include "Fuji-TAC Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (all manufactured by Konica Minolta, Inc.).

The moisture content of the substrate layer 11 is 5.0% or less, preferably 3.0% or less. The moisture content of the substrate layer 11 may be 0.0% or more. When the moisture content of the substrate layer 11 is 5.0% or less, when the polarizing layer 12 is formed, there is a tendency to improve the uniformity of the orientation direction of the polymerizable liquid crystal compound and the dichroic pigment. In particular, when the laminate 10 is stretched, it is easy to see the unevenness of the optical properties, and as a result, even after stretching, it is easy to maintain the good optical properties of the polarizing layer. The moisture content of the substrate layer is measured by the method described in the embodiments described later.

The resin film is preferably thin from the viewpoint of thinning the laminate 10. If it is too thin, it tends to be difficult to ensure impact resistance. The thickness of the resin film may be, for example, 10 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm.

The substrate layer 11 may have a hard coating layer, an anti-reflection layer, or an antistatic layer on at least one surface. The substrate layer 11 may have a hard coating layer, an anti-reflection layer, or an antistatic layer formed only on the surface of the side where the polarizing layer 12 is not formed. The substrate layer 11 may have a hard coating layer, an anti-reflection layer, or an antistatic layer formed only on the surface of the side where the polarizing layer 12 is formed. As the substrate layer 11, a window film described later may also be used.

[Polarizing layer]

The polarizing layer 12 is preferably a layer consisting of a cured product of a composition comprising one or more polymerizable liquid crystal compounds [hereinafter also referred to as polymerizable liquid crystal (a)] and a dichroic pigment, or a layer consisting of a cured product of a composition comprising one or more dichroic pigments exhibiting liquid crystal properties. When the polarizing layer 12 has a polarizing property in the plane direction of the laminate 10, the dichroic pigment and the polymerizable liquid crystal (a) are cured in a state of being horizontally oriented relative to the plane of the laminate 10, or the dichroic pigment exhibiting liquid crystal properties relative to the plane of the laminate 10 is horizontally oriented. When the polarizing layer 12 has a polarizing property in the thickness direction of the laminate 10, the dichroic pigment and the polymerizable liquid crystal (a) are cured in a normal state of being vertically oriented relative to the plane of the laminate 10, or the dichroic pigment exhibiting liquid crystal properties relative to the plane of the laminate 10 is vertically oriented. The polarizing layer 12 is preferably a coating layer, and may be, for example, a cured product of a polarizing layer-forming composition (hereinafter also referred to as composition (A)) containing one or more polymerizable liquid crystals (a) and a dichroic dye.

The thickness of the polarizing layer 12 may be, for example, 0.5 to 10 μm, preferably 1 to 8 μm, and more preferably 1.5 to 5 μm.

The polarizing layer 12 can be formed, for example, by applying the composition (A) on the base material layer 11 or an alignment layer described later, and polymerizing the polymerizable liquid crystal (a) in the obtained coating film.

(Polymerized Liquid Crystal)

The polymerizable liquid crystal (a) is a compound having a polymerizable group and having liquid crystal properties. The polymerizable group refers to a group that participates in the polymerization reaction, preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction using active free radicals, acids, etc. generated from the photopolymerization initiator described later. As polymerizable groups, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxolane, oxetane, etc. can be cited. Among them, acryloyloxy, methacryloyloxy, vinyloxy, oxolane and oxetane are preferred, and acryloyloxy is more preferred. The liquid crystal can be either a thermotropic liquid crystal or a lyotropic liquid crystal. In the case of mixing with a dichroic dye described later, a thermotropic liquid crystal is preferred.

When the polymerizable liquid crystal (a) is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound showing a nematic liquid crystal phase, or it may be a thermotropic liquid crystal compound showing a smectic liquid crystal phase. When the polymerization reaction is utilized as a solidified film to perform a polarizing function, the liquid crystal state displayed by the polymerizable liquid crystal (a) is preferably a smectic phase, and from the perspective of high performance, a higher-order smectic phase is more preferred. Among them, a high-order smectic liquid crystal compound that forms a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase is more preferred, and a high-order smectic liquid crystal compound that forms a smectic B phase, a smectic F phase, or a smectic I phase is further preferred. When the liquid crystal phase formed by the polymerizable liquid crystal (a) is one of these higher-order smectic phases, a polarizing layer with higher polarization performance can be manufactured. In addition, such a polarizing layer with high polarization performance obtains a Bragg peak from a higher-order structure such as a hexagonal phase or a crystalline phase in an X-ray diffraction measurement. The Bragg peak is a peak from a periodic structure derived from molecular orientation, and its periodic interval can be obtained to be From the viewpoint of obtaining higher polarization characteristics, the polarizing layer of the present invention preferably comprises a polymer of the polymerizable liquid crystal (a) polymerized in a smectic phase.

Specific examples of such compounds include compounds represented by the following formula (I) [hereinafter also referred to as compound (I)], etc. The polymerizable liquid crystal (a) may be used alone or in combination of two or more.

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (I)

[In formula (A), X ¹ , X ² and X ³ each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group. The carbon atoms constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom or a nitrogen atom. At least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent.

Y ¹ , Y ² , W ¹ and W ² are independently a single bond or a divalent linking group.

^V1 and ^V2 independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent. _-CH2- constituting the alkanediyl group may be substituted with -O-, -S- or -NH-.

^U1 and ^U2 independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.]

In compound (I), at least one of X ¹ , X ² and X ³ is 1,4-phenylene which may have a substituent, or cyclohexane-1,4-diyl which may have a substituent. In particular, X ¹ and X ³ are preferably cyclohexane-1,4-diyl which may have a substituent, and the cyclohexane-1,4-diyl is more preferably trans-cyclohexane-1,4-diyl. When compound (I) contains cis-cyclohexane-1,4-diyl, it tends to be easy to show smectic liquid crystal properties. In addition, as a substituent optionally possessed by 1,4-phenylene which may have a substituent or cyclohexane-1,4-diyl which may have a substituent, alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl and butyl, cyano groups, and halogen atoms such as chlorine atoms and fluorine atoms can be mentioned. 1,4-phenylene or cyclohexane-1,4-diyl is preferably unsubstituted.

^Y1 and ^Y2 are each independently preferably a single bond, _-CH2CH2- , _-CH2O- , _-COO- , -OCO-, -N=N-, -CRa= ^CRb- , -C≡C- or ^-CRa =N-, and ^Ra and ^Rb are each independently a _{hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y1 and Y2 are more preferably -CH2CH2-} ^{, -COO-, -OCO- or a single bond, and it is more preferred that X1, X2 and X3 all do not include a cyclohexane-1,4-diyl group, and Y1 and Y2 have different bonding forms. When Y1 and} _Y2 ^{have different bonding forms , smectic liquid crystal} properties tend to be easily exhibited.

W ¹ and W ² are preferably independently a single bond, -O-, -S-, -COO- or OCO-, and more preferably independently a single bond or -O-.

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by ^V1 and ^V2 include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10-diyl, tetradecyl-1,14-diyl, and eicosyl-1,20-diyl. ^V1 and ^V2 are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably linear alkanediyl groups having 6 to 12 carbon atoms. By using a linear alkanediyl group having 6 to 12 carbon atoms, crystallinity is improved, and there is a tendency to easily exhibit smectic liquid crystal properties.

Examples of the substituent that the optionally substituted alkanediyl group having 1 to 20 carbon atoms may have include a cyano group and a halogen atom such as a chlorine atom or a fluorine atom. The alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted linear alkanediyl group.

^U1 and ^U2 are both preferably polymerizable groups, and are both more preferably photopolymerizable groups. A polymerizable liquid crystal compound having a photopolymerizable group can be polymerized at low temperatures compared to a polymerizable liquid crystal compound having a thermal polymerizable group, and is therefore advantageous in that liquid crystals can form polymers in a more ordered state.

The polymerizable groups represented by ^U1 and ^U2 may be different from each other, but are preferably the same. Examples of the polymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxolanyl, and oxetane. Among them, acryloyloxy, methacryloyloxy, vinyloxy, oxolanyl, and oxetane are preferred, and methacryloyloxy or acryloyloxy are more preferred.

Examples of such polymerizable liquid crystal compounds include the following.

Among the exemplified compounds, at least one selected from the group consisting of compounds represented by formula (1-2), formula (1-3), formula (1-4), formula (1-6), formula (1-7), formula (1-8), formula (1-13), formula (1-14) and formula (1-15) is preferred.

(Dichroic Pigments)

A dichroic pigment is a pigment having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. As a dichroic pigment, it is preferred to have a characteristic of absorbing visible light, and more preferably, it has an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic pigments include acridine pigments, The dichroic pigments include oxazine pigments, cyanine pigments, naphthalene pigments, azo pigments and anthraquinone pigments. Wherein, as the dichroic pigment, it is preferably an azo pigment. As the azo pigment, monoazo pigments, disazo pigments, triazo pigments, tetraazo pigments and stilbene azo pigments etc. can be mentioned, preferably disazo pigments and triazo pigments. The dichroic pigment can be used alone or in combination. In order to be absorbed in the entire region of visible light, it is preferred to use a combination of more than 3 dichroic pigments, and more preferably to use a combination of more than 3 azo pigments.

Examples of the azo dye include compounds represented by formula (II) (hereinafter, sometimes referred to as “compound (II)”).

T ¹ -A ¹ (-N＝N-A ² ) _p -N＝N-A ³ -T ² (II)

[In formula (II),

^A1 , ^A2 and ^A3 independently represent 1,4-phenylene, naphthalene-1,4-diyl or a divalent heterocyclic group which may have a substituent. ^T1 and ^T2 are electron withdrawing groups or electron donating groups, and exist at positions substantially 180° relative to the azo bond plane. p represents an integer of 0 to 4. When p is 2 or more, each ^A2 may be the same or different. The -N=N- bond may be substituted by a -C=C-, -COO-, -NHCO- or -N=CH- bond within the range showing absorption in the visible region. ]

The substituents optionally possessed by 1,4-phenylene, naphthalene-1,4-diyl and divalent heterocyclic groups in A ¹ , A ² and A ³ include alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl and butyl groups; alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy and butoxy groups; fluorinated alkyl groups having 1 to 4 carbon atoms such as trifluoromethyl groups; cyano groups; nitro groups; halogen atoms such as chlorine and fluorine atoms; substituted or unsubstituted amino groups such as amino, diethylamino and pyrrolidinyl groups (the substituted amino group refers to an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms. The unsubstituted amino group is -NH ₂ .) Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl and hexyl groups. Examples of the alkanediyl group having 2 to 8 carbon atoms include vinyl, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, etc. In order to be included in a high-order liquid crystal structure such as a smectic liquid crystal, A ¹ , A ² and A ³ are preferably 1,4-phenylene groups which are unsubstituted or in which hydrogen is substituted with a methyl group or a methoxy group, or divalent heterocyclic groups, and p is preferably 0 or 1. Among them, from the viewpoint of both the ease of molecular synthesis and high performance, it is more preferable that p is 1 and at least two of the three structures of A ¹ , A ² and A ³ are 1,4-phenylene groups.

Examples of the divalent heterocyclic group include quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, Azoles and benzo ^A2 is a divalent heterocyclic group, preferably a structure in which the molecular bond angle is substantially 180°, and more preferably two 5-membered rings are fused to form benzothiazole, benzimidazole, benzo Azole structure.

^T1 and ^T2 are electron withdrawing groups or electron donating groups, and are preferably different structures from each other. It is further preferred that ^T1 is a combination of an electron withdrawing group and ^T2 is an electron donating group, or that ^T1 is an electron donating group and ^T2 is a combination of an electron withdrawing group. Specifically, ^T1 and T2 are preferably independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group in which ^two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, or a trifluoromethyl group. In order to be included in a high-order liquid crystal structure such as a smectic liquid crystal, a structure with a smaller excluded volume of the molecule is required, and therefore, ^T1 and ^T2 are preferably independently an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms.

Examples of such azo dyes include the following compounds.

In formulae (2-1) to (2-6), B ¹ to B ²⁰ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the substituted amino group and the unsubstituted amino group are as defined above), a chlorine atom or a trifluoromethyl group. From the viewpoint of obtaining high polarization performance, B ² , B ⁶ , B ⁹ , B ¹⁴ , B ¹⁸ and B ¹⁹ are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

n1 to n4 each independently represent an integer of 0 to 3.

When n1 is greater than 2, multiple ^B2 's may be the same or different. When n2 is greater than 2, multiple ^B6's may be the same or different. When n3 is greater than 2, multiple ^B9 's may be the same or different. When n4 is greater than 2, multiple ^B14's may be the same or different.

The anthraquinone dye is preferably a compound represented by formula (2-7).

[In formula (2-7), R ¹ to R ⁸ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

As stated The oxazine dye is preferably a compound represented by formula (2-8).

[In the formula (2-8), R ⁹ to R ¹⁵ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

The acridine dye is preferably a compound represented by formula (2-9).

[In formula (2-9), R ¹⁶ to R ²³ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

^Rx represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ^x in formula (2-7), formula (2-8) and formula (2-9) include methyl, ethyl, propyl, butyl, pentyl and hexyl groups, and examples of the aryl group having 6 to 12 carbon atoms include phenyl, tolyl, silyl and naphthyl groups.

As the cyanine dye, a compound represented by the formula (2-10) or a compound represented by the formula (2-11) is preferred.

[In the formula (2-10), ^D1 and ^D2 independently represent a group represented by any one of the formulas (2-10a) to (2-10d).

n5 represents an integer from 1 to 3.]

[In formula (2-11), D ³ and D ⁴ are mutually independent groups represented by any one of formula (2-11a) to formula (2-11h).

n6 represents an integer from 1 to 3.]

From the viewpoint of obtaining good light absorption characteristics, the content of the dichroic pigment (including its total amount in the case of multiple) is generally 0.1 to 30 parts by mass relative to 100 parts by mass of polymerizable liquid crystal (a), preferably 1 to 20 parts by mass, and more preferably 2 to 15 parts by mass. When the content of the dichroic pigment is less than this range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained. If it is more than this range, there is a situation where the orientation of the liquid crystal molecules is hindered.

(Orientation Layer)

The laminate 10 may include an alignment layer between the base layer 11 and the polarizing layer 12. The alignment layer has an alignment regulating force for aligning the polymerizable liquid crystal constituting the polarizing layer 12 formed on the base layer 11 in a desired direction.

The orientation layer facilitates the liquid crystal orientation of the polymerizable liquid crystal. The state of liquid crystal orientation such as horizontal orientation, vertical orientation, mixed orientation, and inclined orientation varies with the properties of the orientation layer and the polymerizable liquid crystal, and the combination thereof is selected arbitrarily. For example, if the orientation layer is a material that presents a horizontal orientation as an orientation limiting force, the polymerizable liquid crystal can form a horizontal orientation or a mixed orientation. If it is a material that presents a vertical orientation, the polymerizable liquid crystal can form a vertical orientation or an inclined orientation. Expressions such as horizontal and vertical indicate the direction of the long axis of the polymerizable liquid crystal being oriented with the plane of the polarizing layer 12 as a reference. For example, vertical orientation refers to a long axis of a polymerizable liquid crystal oriented in a direction perpendicular to the plane of the polarizing layer 12. The vertical here refers to 90°±20° relative to the plane of the polarizing layer 12.

The orientation restraining force can be arbitrarily adjusted according to the surface state and friction conditions when the orientation layer is formed of an orientation polymer, and can be arbitrarily adjusted according to polarized light irradiation conditions, etc. when the orientation layer is formed of a photo-orientation polymer. In addition, the liquid crystal orientation can be controlled by selecting the physical properties of the polymerizable liquid crystal compound, such as surface tension and liquid crystallinity.

As an orientation layer formed between the substrate layer 11 and the polarizing layer 12, it is insoluble in the solvent used when forming the polarizing layer 12 on the orientation layer, and preferably has heat resistance in the heating treatment for removing the solvent and orienting the liquid crystal. The orientation layer can be an orientation layer composed of an oriented polymer, a photo-orientation layer, and a groove (groove) orientation layer. Among them, in the case of a long roll-shaped resin film, from the viewpoint of being able to easily control the orientation direction, a photo-orientation layer is preferred.

The thickness of the alignment layer may be, for example, in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 to 300 nm.

Examples of the oriented polymer used for the oriented layer composed of the oriented polymer include polyamides having an amide bond in the molecule, gelatins, polyimides having an imide bond in the molecule and their hydrolyzates, i.e., polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyol ... The oriented polymers include oxadiazole, polyethyleneimine, polystyrene, polyvinyl pyrrolidone, polyacrylic acid and polyacrylates, etc. Among them, polyvinyl alcohol is preferred as the oriented polymer. These oriented polymers can be used alone or in combination of two or more.

In the case of forming an oriented layer composed of an oriented polymer on a substrate layer composed of a resin film, the oriented layer composed of the oriented polymer is usually obtained by applying a composition in which the oriented polymer is dissolved in a solvent (hereinafter also referred to as an "oriented polymer composition") to the resin film and removing the solvent, or by applying the oriented polymer composition to the resin film, removing the solvent, and rubbing (rubbing method).

Examples of the solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, butyronitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene; etc. These solvents may be used alone or in combination of two or more.

The concentration of the oriented polymer in the oriented polymer composition may be within a range in which the oriented polymer can be completely dissolved in the solvent, and is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the solid content of the solution.

As the oriented polymer composition, a commercially available material for forming an oriented layer may be used as it is. Examples of commercially available materials for forming an oriented layer include SUNEVER (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.) and Optomer (registered trademark) (manufactured by JSR Corporation).

As a method for coating the oriented polymer composition on the resin film, there can be mentioned known methods such as coating methods such as spin coating, extrusion, gravure coating, die coating, rod coating, and applicator, and printing methods such as flexographic printing. When the laminate of the present invention is manufactured by a continuous manufacturing method in a roll-to-roll format, the coating method generally adopts a printing method such as a gravure coating method, a die coating method, or a flexographic printing method.

The solvent contained in the oriented polymer composition is removed to form a dry film having the oriented polymer. Examples of the method for removing the solvent include natural drying, ventilation drying, heating drying, and reduced pressure drying.

As a rubbing method, there is a method of bringing the oriented polymer film into contact with a rubbing roll. The rubbing roll is a rotatable roll around which a rubbing cloth is wound.

The photo-alignment layer is generally obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as a "photo-alignment layer-forming composition") to a resin film and irradiating it with polarized light (preferably polarized UV light). The photo-alignment layer can arbitrarily control the direction of the alignment restraining force by selecting the polarization direction of the irradiated polarized light, and is therefore more preferred.

A photoreactive group refers to a group that generates liquid crystal orientation capability by irradiation with light. Specifically, a photoreaction that is the origin of the liquid crystal orientation capability, such as orientation induction of molecules caused by irradiation with light, isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, occurs. In the photoreactive group, dimerization reaction or photocrosslinking reaction is preferably performed from the perspective of excellent orientation. As a photoreactive group capable of the above-mentioned reaction, it is preferred to have an unsaturated bond, especially a double bond, and more preferably to have at least one selected from a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

As photoreactive groups having C=C bonds, for example, vinyl, polyene, stilbene, stilbazolyl, styrylpyridinyl, chalcone and cinnamoyl can be cited. From the perspective of easy control of reactivity and orientation restriction during photo-orientation, chalcone and cinnamoyl are preferred. As photoreactive groups having C=N bonds, groups having structures such as aromatic Schiff bases and aromatic hydrazones can be cited. As photoreactive groups having N=N bonds, groups with azobenzene as the basic structure such as azobenzene, azonaphthyl, aromatic heterocyclic azo, disazo and formazan can be cited. As photoreactive groups having C=O bonds, benzophenone, coumarin, anthraquinone and maleimide can be cited. These groups can have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid and halogenated alkyl. Among them, photoreactive groups capable of undergoing photodimerization reaction are preferred, and cinnamoyl and chalcone groups are preferred because they can easily obtain a photo-alignment layer with a relatively small amount of polarized light irradiation required for photo-alignment and excellent thermal stability and temporal stability. As a polymer having a photoreactive group, a cinnamoyl substance having a cinnamic acid structure at the terminal of the polymer side chain is particularly preferred.

From the perspective of the ease of operation of the photo-alignment layer-forming composition and the ability to achieve a highly durable oriented alignment layer, a polymer having a particularly preferred photoreactive group is, for example, a polymer having a group represented by formula (A') in the side chain (hereinafter, also referred to as "polymer (A')" depending on the circumstances).

[In formula (A'), n represents 0 or 1.

^X1 represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH

-or -CH ₂ -.

^Y1 represents a single bond or -O-.

^R1 and ^R2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

* indicates the bonding site corresponding to the polymer backbone. ]

In the formula (A'), when ^X1 is any one of a single bond, -O-, -COO-, -OCO-, -N=N-, -C=C- and _-CH2- , the production of the polymer (A') itself becomes easy, which is particularly preferred.

In formula (A'), ^R1 and ^R2 are independently a hydrogen atom, a halogen atom, a haloalkyl group, a haloalkoxy group, a cyano group, a nitro group, an alkyl group, an alkoxy group, an aryl group, an allyloxy group, an alkoxycarbonyl group, a carboxyl group, a sulfonic acid group, an amino group or a hydroxyl group, and the carboxyl group and the sulfonic acid group can form a salt with an alkali metal ion. Among these, it is further preferred that ^R1 and ^R2 are independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group and a butyl group, and examples of the alkoxy group include a methoxy group, an ethoxy group and a butoxy group.

The main chain of the polymer (A') is not particularly limited, but it is preferred that the polymer (A) has a main chain consisting of any one of a (meth)acrylate unit represented by formula (M-1) or (M-2); a (meth)acrylamide unit represented by formula (M-3) or (M-4); a vinyl ether unit represented by formula (M-5) or (M-6); a (meth)styrene unit represented by formula (M-7) or (M-8), and a vinyl ester unit represented by formula (M-9) or (M-10), and it is further preferred that the polymer (A') has a main chain consisting of units selected from (meth)acrylate units and (meth)acrylamide units. It should be noted that the "main chain of the polymer (A')" referred to here refers to the longest molecular chain among the molecular chains possessed by the polymer (A').

The unit represented by any one of formulas (M-1) to (M-10) and the group described in formula (A') may be directly bonded or bonded via an appropriate linking group. Examples of the linking group include a carbonyloxy group (ester bond), an oxygen atom (ether bond), an imido group, a carbonyl imino group (amide bond), an iminocarbonyl imino group (carbamate bond), a divalent aliphatic hydrocarbon group that may have a substituent, a divalent aromatic hydrocarbon group that may have a substituent, and a divalent group formed by combining these. Specific examples of the divalent aromatic hydrocarbon group that may have a substituent include phenylene, 2-methoxy-1,4-phenylene, 3-methoxy-1,4-phenylene, 2-ethoxy-1,4-phenylene, 3-ethoxy-1,4-phenylene, 2,3,5-trimethoxy-1,4-phenylene, and the like. Among these, the linking group is preferably an aliphatic hydrocarbon group, and more preferably an alkanediyl group having 1 to 11 carbon atoms that may have a substituent. It should be noted that examples of the alkanediyl group include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, and undecamethylene, and these may be straight-chain or branched. In addition, the alkanediyl group may have a substituent. The substituent is, for example, an alkoxy group having 1 to 4 carbon atoms.

In other words, the structural unit having a group represented by formula (A') is preferably represented by formula (A) (hereinafter, also referred to as "structural unit (A)" depending on the situation, and a polymer containing the structural unit (A) is also referred to as "polymer (A)").

[In formula (A), X ¹ , Y ¹ , R ¹ , R ² and n have the same meanings as in formula (A'),

^S1 is an alkanediyl group having 1 to 11 carbon atoms,

The structure represented is a structure represented by any one of formula (M-1) to formula (M-10).]

The molecular weight of the polymer (A') or polymer (A) is preferably in the range of 1×10 ³ to 1×10 ⁷ , expressed as a weight average molecular weight in terms of polystyrene determined by a gel permeation method (GPC method). However, when the molecular weight becomes too high, the solubility in a solvent decreases, the preparation of the alignment layer forming composition becomes difficult, and there is a tendency for the sensitivity to light irradiation to decrease. Therefore, it is preferably in the range of 1×10 ⁴ to 1×10 ⁶ .

The polymer (A) may have a structural unit represented by the formula (B) (hereinafter, also referred to as “structural unit (B)” depending on the case) in addition to the structural unit (A).

[In formula (B), m represents 0 or 1.

^S2 represents an alkanediyl group having 1 to 11 carbon atoms.

The structure represented is a structure represented by any one of formula (M-1) to formula (M-10).

^X2 represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH

-or -CH ₂ -.

^Y2 represents a single bond or -O-.

^R3 and ^R4 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.]

In formula (B), specific examples of ^S2 are the same as the specific examples of ^S1 in formula (A), and specific examples of the alkyl group and alkoxy group of ^R3 and ^R4 are the same as the specific examples of ^R1 and ^R2 in formula (A), respectively.

When the molar fractions of the structural unit (A) and the structural unit (B) relative to all the structural units of the polymer (A) are p and q respectively (p+q is 1), it is preferred to satisfy the relationship of 0.25＜p≤1 and 0≤q＜0.75 [Here, the polymer (A) has the structural unit (A), and the case where p is 1 means that the polymer (A) is a polymer composed of the structural unit (A). In the polymer composed of the structural unit (A), the structural unit (A) may be one type or two or more types]. Among them, the polymer (A) may have structural units other than the structural units (A) and the structural units (B) (hereinafter, also referred to as "other structural units" depending on the circumstances) as long as the orientation ability generated by light irradiation is not significantly impaired.

The polymer (A) can be produced by polymerizing or copolymerizing the monomers of the derived structural unit (A) and the monomers of the derived structural unit (B) or other structural units as required. In the polymerization or copolymerization, an addition polymerization method is usually adopted. As the above-mentioned addition polymerization, free radical polymerization, anionic polymerization and cationic polymerization and other chain polymerization, as well as coordination polymerization can be cited. The polymerization conditions are set according to the type and amount of the monomers used in a manner to meet the above-mentioned preferred molecular weight of the polymer (A).

As a preferred example of the polymer having a photoreactive group, the polymer (A) is described in detail above, but the composition for forming an alignment layer is prepared by dissolving the polymer having the photoreactive group (preferably the polymer (A)) in a suitable solvent. The solvent can dissolve the polymer having the photoreactive group and can be appropriately selected within the range of obtaining a composition for forming an alignment layer with a suitable viscosity. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as N-methylpyrrolidone, N,N-dimethylformamide, γ-butyrolactone, and dimethylacetamide, etc. These solvents may be used alone or in combination.

The content of the polymer or monomer having a photoreactive group relative to the composition for forming the photo-alignment layer is appropriately adjusted according to the type of the polymer or monomer having the photoreactive group and the thickness of the photo-alignment layer to be manufactured, and is preferably set to 0.2% by mass or more, and particularly preferably in the range of 0.3 to 10% by mass. In addition, polymer materials such as polyvinyl alcohol and polyimide and photosensitizers may be included within a range in which the properties of the photo-alignment layer are not significantly impaired.

As a method for applying the composition for forming a photo-alignment layer to a resin film, the same method as the method for applying the above-mentioned oriented polymer composition to a resin film can be cited. As a method for removing the solvent from the applied composition for forming a photo-alignment layer, for example, the same method as the method for removing the solvent from the oriented polymer composition can be cited.

In order to irradiate polarized light, it can be in the form of removing the solvent from the composition for forming a photo-alignment layer coated on a resin film, etc. and directly irradiating polarized light, or it can be in the form of irradiating polarized light from the resin film side, so that the polarized light is transmitted and irradiated. In addition, the polarized light is substantially preferably parallel light. The wavelength of the irradiated polarized light is preferably a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the range of 250 to 400nm is particularly preferred. As a light source for the polarized light irradiation, xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF can be cited, and high-pressure mercury lamps, ultra-high-pressure mercury lamps and metal halide lamps are more preferred. The luminous intensity of ultraviolet rays with a wavelength of 313nm of these lamps is large, so it is preferred. The light of the above-mentioned light source is irradiated by an appropriate polarizer, so that polarized light can be irradiated. As the polarizer, polarizing prisms such as polarizing filters, Glan-Thompson prisms, and Glan Taylor prisms, and wire grid polarizers can be used.

In addition, if shielding is performed during rubbing or polarized light irradiation, a plurality of regions (patterns) in which the directions of liquid crystal alignment are different can be formed.

The groove alignment layer is a film having a concavo-convex pattern or a plurality of grooves on the film surface. When liquid crystal molecules are provided in a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in a direction along the grooves.

As methods for obtaining the groove orientation layer, there are exemplified a method of exposing through an exposure mask having pattern-shaped slits on the surface of a photosensitive polyimide film, followed by development and rinsing to form a concave-convex pattern, a method of forming a layer of a UV curable resin before curing on a plate-shaped original disk having grooves on the surface, and curing the resin layer after moving it to a resin film, and a method of pressing a roll-shaped original disk having a plurality of grooves on a film of a UV curable resin before curing formed on a resin film to form concave-convex patterns, and then curing the same, etc. Specifically, there are methods described in Japanese Patent Application Laid-Open Nos. 6-34976 and 2011-242743.

In order to obtain an orientation with little orientation disorder, the width of the convex portion of the groove orientation layer is preferably 0.05 μm to 5 μm, the width of the concave portion is preferably 0.1 μm to 5 μm, and the depth of the step difference of the concave and convex is preferably 2 μm or less, preferably 0.01 μm to 1 μm or less.

(Other layers)

The laminate 10 may further have an adhesive layer on the side of the polarizing layer 12. The adhesive layer is used to attach the laminate 10 to an image display element, a window film or a touch sensor of a display device, or to laminate a phase difference layer and a laminate. As the adhesive, a (meth) acrylic adhesive, a styrene adhesive, a silicone adhesive, a rubber adhesive, a urethane adhesive, a polyester adhesive, an epoxy copolymer adhesive, etc. can be used.

The laminate 10 may have a phase difference layer. As the phase difference layer, there may be mentioned a λ/4 plate, a λ/2 plate, a positive C plate, a λ/4 plate with reverse wavelength dispersion, a λ/2 plate with reverse wavelength dispersion, and a combination thereof. As a combination of phase difference layers, there may be mentioned a combination of a λ/4 plate with reverse wavelength dispersion and a positive C plate, and a combination of a λ/2 plate and a λ/4 plate. The phase difference layer may be made of a transparent resin film forming the above-mentioned substrate layer and a composition containing a polymerizable liquid crystal compound. The phase difference layer may be made by coating a composition containing a polymerizable liquid crystal compound on an orientation film and curing the polymerizable liquid crystal compound. The phase difference layer may be a layer containing a cured product of a polymerizable liquid crystal compound, or a layer further containing an orientation film and a substrate. In order to make a phase difference layer, for example, the polymerizable liquid crystal compound exemplified in the description of the above-mentioned polarizing layer 12, the polymerizable liquid crystal compound described in Japanese Patent Publication No. 2010-31223 and Japanese Patent Publication No. 2009-173893, etc. may be used. The oriented film included in the phase difference layer may be, for example, the oriented film exemplified in the description of the polarizing layer 12. The substrate included in the phase difference layer may be, for example, the resin film exemplified in the description of the substrate layer 11. The phase difference layer may be laminated via the above-mentioned adhesive layer.

The laminate 10 may have a surface treatment layer (coating layer) such as a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, or an antifouling layer.

The laminate 10 may have a window film and a shading pattern (outer frame) arranged on its visible side with the polarizing layer 12 as a reference. The window film includes a hard coating layer on at least one side of the transparent substrate layer. The window film is not as hard as the existing glass, but has a flexible property. The shading pattern can be used to hide the wiring of the display device so that the user cannot see it. The laminate 10 can be stacked on a touch sensor.

<Method for producing laminate>

The polarizing layer 12 is formed by coating the composition (A) on the alignment layer in the presence of the substrate layer 11. The composition (A) may further contain a polymerization initiator, a leveling agent, a solvent, a photosensitizer, a polymerization inhibitor, a leveling agent, etc. in addition to the above-mentioned dichroic dye and polymerizable liquid crystal compound.

(Polymerization initiator)

The polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal, etc. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred from the viewpoint of being independent of the phase state of the thermotropic liquid crystal.

Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodine compounds, Salt and sulfonium salt, etc.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether.

Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholinyl-1-(4-methylthiophenyl)propane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propane-1-one, 1-hydroxycyclohexyl phenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1-one.

Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

Examples of the triazine compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(2-(5-methylfuran-2-yl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)acetonitrile]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)acetonitrile]-1,3,5-triazine, etc.

As the polymerization initiator, a commercially available initiator can be used. Examples of commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, and OXE03 (manufactured by Ciba Specialty Chemicals Co., Ltd.); SEIKUOL (registered trademark) BZ, Z, and BEE (manufactured by Seiko Chemical Co., Ltd.); Kayacure (registered trademark) BP100 and UVI-6992 (manufactured by Dow Chemical Co., Ltd.); Adeka Optomer SP-152, N-1717, N-1919, SP-170, Adeka Arkls NCI-831, and Adeka Arkls NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A and TAZ-PP (manufactured by Japan Sibel Chemical Co., Ltd.); Hegner Co., Ltd.); and TAZ-104 (Sanwa Chemical Co., Ltd.); etc. The composition (A) may contain one polymerization initiator, or may contain two or more polymerization initiators depending on the light source.

The content of the polymerization initiator in the composition (A) can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal. The content of the polymerization initiator is generally 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass relative to 100 parts by mass of the content of the polymerizable liquid crystal. When the content of the polymerization initiator is within the above range, polymerization can be performed without interfering with the orientation of the polymerizable liquid crystal.

(Sensitizer)

The composition (A) may contain a sensitizer. As the sensitizer, a photosensitizer is preferred. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and anthracene containing an alkoxy group (e.g., dibutoxyanthracene, etc.); phenothiazine and rubrene, etc.

When the composition (A) contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal contained in the composition (A) can be further promoted. The amount of the sensitizer used is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal.

(Inhibitor)

From the viewpoint of stably carrying out the polymerization reaction, the composition (A) may contain a polymerization inhibitor. The polymerization inhibitor can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal.

Examples of the polymerization inhibitor include hydroquinone, alkoxy-containing hydroquinone, alkoxy-containing catechol (eg, butyl catechol), pyrogallol, and radical scavengers such as 2,2,6,6-tetramethyl-1-piperidinyloxy radicals; thiophenols; β-naphthylamines; and β-naphthols.

When the composition (A) contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and further preferably 0.5 to 3 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal. When the content of the polymerization inhibitor is within the above range, polymerization can be performed without interfering with the orientation of the polymerizable liquid crystal.

(Leveling agent)

The composition (A) may contain a leveling agent. A leveling agent is an additive that has the function of adjusting the fluidity of the composition and making the film obtained by coating the composition flatter. Examples of the leveling agent include organic modified silicone oil-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Specific examples include DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, and FZ2123 (all manufactured by Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, and KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, and TSF4460 (all manufactured by Momentive Performance Materials Japan Co., Ltd.), fluorinert (registered trademark) FC-72, fluorinert FC-40, fluorinert FC-43, fluorinert FC-3283 (all manufactured by Sumitomo 3M Co., Ltd.), MEGAFAC (registered trademark) R-08, MEGAFAC R-30, MEGAFAC R-90, MEGAFAC F-410, MEGAFAC F-411, MEGAFAC F-443, MEGAFAC F-445, MEGAFAC F-470, MEGAFAC F-477, MEGAFAC F-479, MEGAFAC F-482, MEGAFAC F-483 (all manufactured by DIC Corporation), F-Top (trade name) EF301, Ftop EF303, Ftop EF351, Ftop EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40, SA-100 (all of the above are manufactured by AGC Seimi Chemical Co., Ltd.), trade name E1830, trade name E5844 (manufactured by Daikin Fine Chemical Research Institute Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all trade names: manufactured by BM Chemie Co., Ltd.), etc. Among them, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferred.

When the composition (A) includes a leveling agent, the content of the leveling agent is preferably 0.01 to 5 parts by mass relative to 100 parts by mass of the content of the polymerizable liquid crystal, more preferably 0.1 to 5 parts by mass, and further preferably 0.1 to 3 parts by mass. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal, and there is a tendency for the obtained polarizing layer to become smoother. When the content of the leveling agent relative to the polymerizable liquid crystal exceeds the above range, there is a tendency for the obtained polarizing layer to be prone to unevenness. It should be noted that the composition (A) may contain two or more leveling agents.

(Solvent)

The composition (A) may contain a solvent. Generally, the viscosity of the polymerizable liquid crystal compound is high, so coating becomes easy by forming a composition (A) dissolved in a solvent, and as a result, the formation of the polarizing layer becomes easy in many cases. As the solvent, a solvent that can completely dissolve the polymerizable liquid crystal compound is preferred, and a solvent that is inert to the polymerization reaction of the polymerizable liquid crystal compound is preferred.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorinated solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone, etc. These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the composition (A). In other words, the content of the solid component of the composition (A) is preferably 2 to 50% by mass. When the content of the solid component is less than 50% by mass, the viscosity of the composition (A) is low, so the thickness of the polarizing layer tends to become roughly uniform. As a result, there is a tendency that the polarizing layer is not easy to produce unevenness. In addition, the content of the above-mentioned solid component can be determined by considering the thickness of the polarizing layer to be manufactured.

(Reactive Additives)

The composition (A) may contain a reactive additive. As a reactive additive, it is preferred that the molecule has a carbon-carbon unsaturated bond and an active hydrogen reactive group. It should be noted that the "active hydrogen reactive group" here refers to a group reactive to a group having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH ₂ ), a glycidyl group, Representative examples include oxazoline, carbodiimide, aziridine, imide, isocyanate, thioisocyanate, and maleic anhydride. The number of carbon-carbon unsaturated bonds and active hydrogen reactive groups possessed by the reactive additive is usually 1 to 20, preferably 1 to 10.

It is preferred that at least two active hydrogen reactive groups exist in the reactive additive. In this case, the plurality of active hydrogen reactive groups may be the same or different.

The carbon-carbon unsaturated bond possessed by the reactive additive may be a carbon-carbon double bond or a carbon-carbon triple bond, or a combination thereof, preferably a carbon-carbon double bond. Among them, as a reactive additive, as a vinyl group and/or a (meth) acrylic group, it is preferred to contain a carbon-carbon unsaturated bond. In addition, the active hydrogen reactive group is preferably selected from at least one of an epoxy group, a glycidyl group and an isocyanate group, i.e., a reactive additive, more preferably a reactive additive having an acrylic group and an isocyanate group.

Specific examples of reactive additives include compounds having a (meth) acrylic acid group and an epoxy group, such as methacryloyloxy glycidyl ether and acryloxy glycidyl ether; compounds having a (meth) acrylic acid group and an oxetane group, such as acrylate and methacrylate; compounds having a (meth) acrylic acid group and a lactone group, such as acrylate lactone ester and methacrylate lactone ester; vinyl Oxazoline, isopropenyl Azoline and other Compounds having an oxazoline group; oligomers of compounds having a (meth)acrylic acid group and an isocyanate group, such as isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate. In addition, compounds having a vinyl group, a vinylidene group, and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride, can be cited. Among them, methacryloyloxy glycidyl ether, acryloxy glycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyl maleic anhydride, and the like are preferred. Oxazoline, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate and oligomers thereof are preferred, and isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate and oligomers thereof are particularly preferred.

Specifically, a compound represented by the following formula (Y) is preferred.

[In formula (Y), n represents an integer of 1 to 10, and R ^1' represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 5 to 20 carbon atoms. One of the two R ^2's in each repeating unit is -NH-, and the other is a group represented by >N-C(=O)-R ^3' . R ^3' represents a group having a hydroxyl group or a carbon-carbon unsaturated bond.

At least one of R ^{3' in} formula (Y) is a group having a carbon-carbon unsaturated bond.]

Among the reactive additives represented by the formula (Y), particularly preferred are compounds represented by the following formula (YY) (hereinafter, sometimes referred to as compound (YY)) (wherein n has the same meaning as described above).

Among the compounds (YY), commercially available products may be used as they are or may be purified as necessary. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF Corporation).

When the composition (A) contains a reactive additive, the content of the reactive additive is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal.

Before the composition (A) is applied to the substrate layer, the substrate layer preferably adjusts the moisture content. The moisture content of the substrate layer can be 5.0% or less, preferably 3.0% or less. The moisture content of the substrate layer 11 can be 0.0% or more. When the composition (A) is applied to a substrate layer with such a moisture content, the uniformity of the orientation direction of the polymerizable liquid crystal and the dichroic pigment is improved. In particular, when the laminate 10 is stretched, it is easy to see the unevenness of the optical properties, and as a result, even after stretching, it is easy to maintain the good optical properties of the polarizing layer. The moisture content of the substrate layer is measured by the method described in the embodiments described later.

The moisture content of the substrate layer is adjusted by heating or humidifying the substrate layer. Heating the substrate layer is effective in adjusting the elastic modulus of the laminate. When the substrate layer is heated, the heating temperature may be 50° C. to 150° C., and the heating time may be 1 minute to 10 minutes.

(Coating method)

As a method for applying the composition (A) on the substrate layer 11 or the orientation layer, there can be cited the use of extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, slit coating, micro-gravure printing, die coating, inkjet, etc. In addition, there can be cited the method of coating with a coating machine such as a dip coater, a rod coater, a spin coater, etc. Among them, in the case of continuous coating in a roll-to-roll (Roll to Roll) form, it is preferably a coating method using a micro-gravure printing method, an inkjet method, a slit coating method, and a die coating method, and in the case of coating on a monolithic object such as glass, a spin coating method with high uniformity is preferably used. In the case of coating in the form of Roll to Roll, it is also possible to form an orientation layer by coating an oriented polymer composition or a composition for forming a light orientation layer on the substrate layer 11, and further continuously coating the composition (A) on the obtained orientation layer.

(Drying method)

As a drying method for removing the solvent contained in the composition (A), for example, natural drying, ventilation drying, heating drying, reduced pressure drying and a method combining them can be cited. Among them, natural drying or heating drying is preferred. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, and further preferably in the range of 50 to 130°C. The drying time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. The composition for forming a photo-aligned layer and the oriented polymer composition can also be dried in the same manner.

(Polymerization method)

As a method for polymerizing a polymerizable liquid crystal compound, photopolymerization is preferred. Photopolymerization is performed by irradiating a composition (A) containing a polymerizable liquid crystal compound coated on the substrate layer 11 or the orientation layer with active energy rays. As the active energy rays to be irradiated, they can be appropriately selected according to the type of polymerizable liquid crystal compound contained in the dry film (especially the type of photopolymerizable functional group possessed by the polymerizable liquid crystal compound) and the type and amount of the photopolymerization initiator when a photopolymerization initiator is included. Specifically, as active energy rays, one or more lights selected from visible light, ultraviolet light, infrared light, X-rays, α rays, β rays and γ rays can be cited. Among them, from the viewpoint of easy control of the progress of the polymerization reaction and the viewpoint of being able to use a device widely used in the art as a photopolymerization device, ultraviolet rays are preferred, and the type of polymerizable liquid crystal compound is preferably selected in a manner that photopolymerization can be performed using ultraviolet rays.

As the light source of the active energy line, for example, there can be mentioned a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting a wavelength range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, and the like.

The ultraviolet irradiation intensity is usually 10mW/ ^cm2 to 3000mW/ ^cm2 . The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for the activation of a cationic polymerization initiator or a free radical polymerization initiator. The irradiation time is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and further preferably 0.1 seconds to 1 minute. When irradiated once or multiple times with such an ultraviolet irradiation intensity, the cumulative light amount is, for example, 10mJ/ ^cm2 to 3000mJ/ ^cm2 , preferably 50mJ/ ^cm2 to 2000mJ/ ^cm2 , and more preferably 100mJ/ ^cm2 to 1000mJ/ ^cm2 . When the cumulative light amount is less than the lower limit, the curing of the polymerizable liquid crystal compound becomes insufficient, and sometimes good transferability cannot be obtained. On the contrary, when the cumulative light amount exceeds the upper limit, there is a case where the optical film containing the optical heterogeneous layer is colored.

＜Display device＞

The display device is not particularly limited, and examples thereof include organic electroluminescent (organic EL) display devices, inorganic electroluminescent (inorganic EL) display devices, liquid crystal display devices, touch panel display devices, electric field emission display devices, etc. The display device of this embodiment has a stretchable laminate 10, and thus can be preferably used in a stretchable display device, and in particular can be preferably used in an organic EL display device.

The present invention will be described in further detail below using Examples. "%" and "parts" in the examples refer to mass % and mass parts unless otherwise specified.

Example

[Tensile elastic modulus]

The tensile modulus was measured in accordance with JIS K7161 using UTM (Universal Testing Machine, Autography AG-X, Shimadzu Corporation) under tension in the absorption axis direction and the transmission axis direction. The tensioning conditions were at room temperature (temperature 23°C), speed 1.5 mm/min, width 40 mm, and point distance 50 mm.

[Total haze value]

The total haze value of the laminate before and after stretching in each stretching direction and stretching ratio was measured using a haze meter (HM-150, Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K7136. The absolute value of the difference between the total haze value of the laminate before and after stretching at each stretching ratio was defined as ΔH.

It should be noted that the total haze value can be calculated according to the following formula.

Total haze value (%) = scattered transmittance (%) / total light transmittance (%) × 100

[Visibility Correction Single Transmittance and Visibility Correction Polarization Degree]

For the laminate before and after stretching in each stretching direction and stretching ratio, the visibility-corrected single transmittance and the visibility-corrected polarization degree were measured using an ultraviolet-visible spectrophotometer (V7100, JASCO Corporation) in accordance with JIS Z 8701. The absolute values of the differences between the visibility-corrected single transmittance and the visibility-corrected polarization degree of the laminate before and after stretching at each stretching ratio were denoted as ΔT and ΔP, respectively.

[Water content of substrate layer]

The moisture content of the base material layer was calculated based on the following formula using MS-70, a heat-drying moisture meter manufactured by A&D Co., Ltd. The size of the base material layer when measuring the moisture content was 100 mm×100 mm.

Water content of substrate layer (%) = 100 × ( _WA - _WB - _WP ) / ( _WB - _W2 )

W _P = W ₁ － _{W 2}

_WA is the weight of the sample dish on which the base material layer is placed.

W _B is the weight when the sample dish on which the base material layer is placed is heated at 120°C and the time change of the water content becomes 0.02%/min or less.

_W1 is the weight of the sample dish.

_W2 is the weight when the sample dish is heated at 120°C and the time change of the water content becomes 0.02%/min or less.

_WP reflects the surface moisture content of the sample dish.

[Appearance evaluation]

The laminate stretched in each stretching direction and stretching ratio was visually observed to evaluate unevenness, cracks, haze, and the presence or absence of breakage.

○: No unevenness, cracks, haze, or breakage

×: No unevenness, cracks, haze, or breakage

××: Cracks, breaks, or unevenness

[Polymerizable liquid crystal compound]

The polymerizable liquid crystal compound used was 75 parts of a polymerizable liquid crystal compound represented by formula (1-6) [hereinafter also referred to as compound (1-6)] and 25 parts of a polymerizable liquid crystal compound represented by formula (1-7) [hereinafter also referred to as compound (1-7)].

Compound (1-6) and Compound (1-7) were synthesized by the method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

As the dichroic dye, an azo dye described in Examples of JP-A-2013-101328 represented by the following formulas (2-1a), (2-1b), and (2-3a) was used.

[Polarizing layer forming composition]

The polarizing layer forming composition is prepared as follows: 75 parts by weight of the compound (1-6), 25 parts by weight of the compound (1-7), 2.5 parts by weight of the azo dyes represented by the above formulas (2-1a), (2-1b), and (2-3a) as dichroic dyes, 6 parts by weight of 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane-1-one (Irgacure 369, manufactured by BASF Japan) as a polymerization initiator, and 1.2 parts by weight of a polyacrylate compound (BYK-361N, manufactured by BYK-Chemie) as a leveling agent are mixed in 400 parts of toluene as a solvent, and the resulting mixture is stirred at 80° C. for 1 hour.

[Polymer 1]

The polymer 1 is a polymer having a photoreactive group composed of the following structural units.

The molecular weight of the polymer 1 measured by GPC showed a number average molecular weight of 28,200, Mw/Mn of 1.82, and a monomer content of 0.5%.

[Alignment layer forming composition]

As the composition for forming an alignment layer, a solution prepared by dissolving the polymer 1 in cyclopentanone at a concentration of 5% by weight was used.

[Example 1]

A substrate layer made of triacetyl cellulose (TAC) with a thickness of 25 μm was prepared. The dried substrate layer was heated at 120° C. for 5 minutes to a moisture content of 2%. The composition for forming an alignment layer was applied on the substrate layer by a bar coating method, and the coating was dried at 80° C. for 1 minute. The thickness was 100 nm.

Next, a UV irradiation device (SPOT CURE SP-7, manufactured by Ushio Electric Co., Ltd.) was used to irradiate polarized light having a cumulative light amount of 100 mJ/ ^cm2 measured at a wavelength of 365 nm through a wire grid (UIS-27132##, manufactured by Ushio Electric Co., Ltd.) to impart alignment ability, thereby obtaining an alignment layer.

The polarizing layer-forming composition was coated on the obtained orientation layer by a rod coating method. After heating and drying the coating film at 100°C for 2 minutes, it was cooled to room temperature to obtain a dry film. Using a UV irradiation device (SPOT CURE SP-7), the obtained film was irradiated with ultraviolet rays in a manner of cumulative light intensity of 1200mJ/ ^cm2 (365nm is the reference) to obtain a polarizing layer with a thickness of 3μm. The tensile elastic modulus ( _EA and _ET ) in the absorption axis direction and the transmission axis direction of the obtained laminate was measured. The _EA of the laminate was 3180MPa and the _ET was 3900MPa. In addition, before stretching, after stretching in the absorption axis direction at a stretching rate of 5%, and after stretching in the transmission axis direction at a stretching rate of 5%, the total haze value, visibility-corrected monomer transmittance, visibility-corrected polarization degree and appearance were evaluated respectively. The results are shown in Table 1. Stretching was performed using UTM. The stretching conditions were a speed of 1.5mm/min, a width of 40mm, and a point distance of 50mm at room temperature.

[Example 2]

A laminate was prepared in the same manner as in Example 1 except that the stretching ratio in the absorption axis direction and the stretching ratio in the transmission axis direction were each 10%.

[Example 3]

A laminate was prepared in the same manner as in Example 1 except that the substrate layer composed of triacetylcellulose (TAC) was changed to a substrate layer composed of polyethylene terephthalate (PET). The thickness of the substrate layer composed of PET was 50 μm. The _EA of the laminate was 4500 MPa and the _ET was 3300 MPa.

[Example 4]

In Example 3, a laminate was produced in the same manner as in Example 3 except that the stretching ratio in the absorption axis direction and the stretching ratio in the transmission axis direction were each set to 10%.

[Comparative Example 1]

A polyvinyl alcohol film (trade name "KURARAY VINYLON VF-PE#3000" manufactured by Kuraray Co., Ltd.) having an average degree of polymerization of about 2400, a saponification degree of 99.9 mol % and a thickness of 30 μm was immersed in pure water at 37° C. and then immersed in an aqueous solution containing iodine and potassium iodide at 30° C. (iodine/potassium iodide/water (weight ratio) = 0.05/1.7/100).

Immerse in a 58°C aqueous solution containing potassium iodide and boric acid (potassium iodide/boric acid/water (weight ratio) = 12/3.2/100). After washing the film with pure water at 15°C, dry it at 80°C to obtain a polarizing layer with a thickness of about 12μm in which iodine is adsorbed and oriented in polyvinyl alcohol. Stretching is mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.5 times. A substrate layer composed of a TAC film with a thickness of 25μm is bonded to one side of the obtained polarizing layer via an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin [trade name "KC2UA" manufactured by Konica Minolta, Ltd.] to form a polarizer. In this laminate, _EA is 8500MPa and _ET is 4950MPa.

The obtained laminate was stretched at a stretching ratio of 5% in the absorption axis direction and at a stretching ratio of 5% in the transmission axis direction, and then the tensile elastic moduli ( _EA and _ET ) were measured respectively.

In addition, the total haze value, visibility-corrected single transmittance, visibility-corrected polarization degree and appearance were evaluated before stretching, after stretching at a stretching rate of 5% in the absorption axis direction and after stretching at a stretching rate of 5% in the transmission axis direction.

[Comparative Example 2]

In Comparative Example 1, a laminate was prepared in the same manner as in Comparative Example 1 except that the stretching ratio in the absorption axis direction and the stretching ratio in the transmission axis direction were each 10%.

[Comparative Example 3]

In Comparative Example 1, a laminate was prepared in the same manner as in Comparative Example 1 except that a polyethylene terephthalate (PET) film (Toray Industries, Inc.) was used instead of the 25 μm thick TAC film. The thickness of the PET film was 38 μm. The _EA of the laminate was 9900 MPa and the _ET was 5100 MPa.

[Comparative Example 4]

A laminate was produced in the same manner as in Example 1 except that the base material layer was not dried by heating.

As shown in Table 1, the differences in total haze, visibility-corrected monomer transmittance, and visibility-corrected polarization degree before and after stretching of the laminated bodies of Examples 1 to 4 are small, and the laminated bodies also show a good appearance after stretching. On the other hand, in Comparative Example 1, the difference in visibility-corrected polarization degree before and after stretching is large, and a sufficient result cannot be obtained in the appearance evaluation after stretching. In Comparative Example 2, breakage occurred during stretching. In Comparative Example 3, the differences in total haze value, visibility-corrected monomer transmittance, and visibility-corrected polarization degree are all large, and a sufficient result cannot be obtained in the appearance evaluation. In Comparative Example 4, unevenness occurs in the polarization layer, and the appearance deteriorates.

[Tensile test]

After the reflectivity of the laminates prepared in Examples 5, 6 and Comparative Example 5 was measured, the laminates were stretched at a speed of 2.5 mm/min and a stretching rate of 5% at a temperature of 60°C using UTM, and then maintained in the stretched state to measure the reflectivity and evaluate the appearance. The sample for measuring each laminate had an initial stretching direction length of 50 mm and a width of 40 mm. The stretching test was performed for the cases of stretching in the absorption axis direction (MD direction) and the transmission axis direction (TD direction).

The reflectivity was measured by sequentially placing a sample for measurement and a reflective plate (aluminum plate, reflectivity 97%) in a spectrophotometer (CM-2600d, manufactured by Konica Minolta, Inc., SCI model). The absolute value Δ reflectivity [%] of the difference between the reflectivity [%] measured before stretching and the reflectivity [%] measured in the stretched state was calculated. Δ reflectivity [%] can be calculated using the following formula.

Δ reflectivity [%] = |Y (before stretching) - Y (stretching state) |

Y (before stretching) = reflectance measured before stretching [%]

Y (stretched state) = reflectivity measured in the stretched state [%]

Evaluation of Appearance Unevenness, cracks/haze, and the presence or absence of breakage were evaluated by visual observation.

○: No unevenness, cracks, haze, or breakage

×: No unevenness, cracks, haze, or breakage

××: Cracks, breaks, or unevenness

[Preparation of a coating-type phase difference layer with adhesive layers on both sides]

(Alignment film forming composition)

5 parts by mass of a photo-alignment material having a structure represented by the following formula (weight average molecular weight: 30,000) and 95 parts by mass of cyclopentanone (solvent) were mixed, and the obtained mixture was stirred at 80° C. for 1 hour to obtain an alignment film-forming composition.

(Composition for forming phase difference layer)

To 100 parts by mass of a mixture in which a polymerizable liquid crystal compound A represented by the following formula and a polymerizable liquid crystal compound B were mixed at a mass ratio of 90:10, 1.0 parts by mass of a leveling agent (F-556; manufactured by DIC Corporation) and 6 parts by mass of a polymerization initiator, namely 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butane-1-one (IRGACURE 369, manufactured by BASF JAPAN Corporation) were added. N-methyl-2-pyrrolidone (NMP) was further added so that the solid content concentration became 13%, and the mixture was stirred at 80°C for 1 hour to obtain a composition for forming a phase difference layer.

(Polymerizable Liquid Crystal Compound A)

(Polymerizable Liquid Crystal Compound B)

The polymerizable liquid crystal compound A was produced by the method described in Japanese Unexamined Patent Application Publication No. 2010-31223. The polymerizable liquid crystal compound B was produced based on the method described in Japanese Unexamined Patent Application Publication No. 2009-173893.

(Preparation of a laminate composed of a substrate, an alignment film, and a layer formed by curing a polymerizable liquid crystal compound)

As a substrate, a 50 μm thick cycloolefin resin film [ZF-14-50, manufactured by Zeon Co., Ltd. of Japan] was prepared and subjected to corona treatment. The composition for forming an oriented film was applied to the surface subjected to corona treatment using a rod coater. The coated film was dried at 80°C for 1 minute. A polarized UV irradiation device [trade name "SPOT CURE SP-9" of Ushio Electric Co., Ltd.] was used to irradiate the dried coated film with polarized UV at an axial angle of 45° to obtain an oriented film. The irradiation of polarized UV was performed in a manner such that the accumulated light amount at a wavelength of 313 nm was 100 mJ/ ^cm2 .

Next, the retardation layer-forming composition was applied onto the alignment film using a bar coater, and the applied film was dried at 120° C. for 1 minute. The dried applied film was irradiated with ultraviolet light using a high-pressure mercury lamp (trade name: “IRGACUREVB-15201BY-A” from Ushio Electric Co., Ltd.).

The ultraviolet irradiation step was performed under a nitrogen atmosphere so that the cumulative light amount at a wavelength of 365 nm was 400 mJ/cm ^2. After the irradiation, the cured film was placed in an oven set at 5° C. for 20 seconds as a cooling step. After being taken out of the oven, the ultraviolet irradiation step and the cooling step were immediately performed again (i.e., the total cumulative light amount of the two ultraviolet irradiations was 800 mJ/cm ² ). A laminate consisting of a substrate, an alignment film, and a layer formed by curing a polymerizable liquid crystal compound was obtained.

The adhesive layer described later is laminated on the cured layer of the polymerizable liquid crystal compound of the laminated body. Next, the substrate is peeled off from the laminated body, and the adhesive layer is similarly laminated on the exposed surface.

In this way, a coating type phase difference layer with double-sided adhesive layers composed of an adhesive layer, a layer of a polymerizable liquid crystal compound cured, an alignment film, and an adhesive layer was prepared. The layer of the polymerizable liquid crystal compound cured had a phase difference value of λ/4.

[Preparation of film-type phase difference layer with adhesive layers on both sides]

A uniaxially stretched cyclic olefin resin film, namely Zeonor Film (Zeon Corporation, Japan, in-plane phase difference value with respect to light of wavelength λ=550 nm: 138 nm) was prepared, and adhesive layers described later were laminated on both surfaces of the film.

(Adhesive layer)

An acrylic resin was obtained by reacting 70 parts by mass of butyl acrylate, 20 parts by mass of ethyl acrylate, 2.0 parts by mass of acrylic acid, and 0.2 parts by mass of a radical polymerization initiator (2,2'-azobisisobutyronitrile) at 55°C with stirring in a nitrogen atmosphere.

100 parts by mass of acrylic resin, 0.7 parts by mass of crosslinking agent ("CORONATE L" manufactured by Tosoh Corporation), and 0.5 parts by mass of silane coupling agent ("X-12-981" manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed, and ethyl acetate was added to give a total solid content concentration of 10% to obtain an adhesive composition.

The adhesive composition was applied to the release-treated surface of the polyethylene terephthalate film (thickness 38 μm) with an applicator so that the thickness after drying was 25 μm. The coating was dried at 100° C. for 1 minute to obtain a film having an adhesive layer. Thereafter, another polyethylene terephthalate film (thickness 38 μm) that had been subjected to a release treatment was attached to the adhesive layer. Thereafter, the film was aged for 7 days at a temperature of 23° C. and a relative humidity of 50% RH.

<Example 5>

The above-mentioned coating type phase difference layer with two-sided adhesive layer is attached to the polarizing layer of the laminate composed of substrate layer/polarizing layer prepared in Example 1 via an adhesive layer on one side. The slow axis of the layer formed by curing the polymerizable liquid crystal compound is 45 degrees relative to the absorption axis of the polarizing layer. In this way, a circular polarizer composed of substrate layer/polarizing layer/adhesive layer/coating type phase difference plate/adhesive layer is prepared. The obtained circular polarizer is subjected to a tensile test. The results are shown in Table 2.

<Example 6>

The polarizing layer of the laminate composed of the substrate layer/polarizing layer prepared in Example 1 and the above-mentioned film-type phase difference layer are bonded via an adhesive layer. The slow axis of the film-type phase difference layer is 45 degrees relative to the absorption axis of the polarizing layer. In this way, a circular polarizer composed of a substrate layer/polarizing layer/adhesive layer/film-type phase difference layer/adhesive layer is prepared. The obtained circular polarizer is subjected to a tensile test. The results are shown in Table 2.

<Comparative Example 5>

A circular polarizing plate consisting of substrate/polarizing layer/adhesive layer/coating type phase difference layer/adhesive layer was prepared in the same manner as in Example 5 except that the laminate consisting of substrate layer/polarizing layer prepared in Comparative Example 4 was used. The obtained circular polarizing plate was subjected to a tensile test. The results are shown in Table 2.

[Table 2]

Explanation of symbols

10 laminate, 11 substrate layer, 12 polarizing layer

Claims (8)

1. A laminate comprising a base layer and a polarizing layer, which is stretchable,

the substrate layer has a water content of 5.0% or less,

the elongation at break of the laminate in both the absorption axis direction and the transmission axis direction is 5% to 20%,

the laminate satisfies the following formula (1),

|E _A －E _T |/|E _A +E _T |≤0.25(1)

wherein E is _A And E is _T Tensile elastic modulus, E, respectively representing absorption axis direction and transmission axis direction _A 50MPa to 15000MPa, E _T 50MPa to 15000MPa.

2. The laminate according to claim 1, wherein the total haze value is 3% or less.

3. The laminate according to claim 1 or 2, wherein the polarizing layer has a thickness of 0.5 μm to 10 μm.

4. The laminate according to any one of claims 1 to 3, wherein the polarizing layer is composed of a cured product of a composition for forming a polarizing layer comprising a polymerizable liquid crystal compound and a dichroic dye.

5. The laminate according to claim 4, wherein the content of the dichroic dye in the polarizing layer is 0.1 to 30 parts by mass based on 100 parts by mass of the polymerizable liquid crystal compound.

6. A laminate with an adhesive layer, further comprising an adhesive layer on the polarizing layer side of the laminate according to any one of claims 1 to 5.

7. The laminated body with a retardation layer according to claim 6, wherein the laminated body with an adhesive layer has a retardation layer laminated via the adhesive layer.

8. A display device in which the laminate according to any one of claims 1 to 5, the laminate with an adhesive layer according to claim 6, or the laminate with a retardation layer according to claim 7 is bonded to an image display element.