KR102724035B1 - Laminate - Google Patents

Abstract

To provide a stretchable laminate in which optical properties do not change and appearance defects do not occur even when stretched. A stretchable laminate comprising a substrate layer and a polarizing layer, wherein the moisture content of the substrate layer is 5.0% or less and satisfies the following equation (1).
｜E _A －E _T ｜／｜E _A ＋E _T ｜≤0.25 (1)
[In the formula, E _A and E _T represent the tensile elastic moduli in the absorption axis direction and the transmission axis direction, respectively.]

Description

Laminate

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

Patent document 1 proposes a display device that can be extended. Patent document 2 proposes a polarizing plate that can be thermally bent.

Patent Document 1: Korean Publication No. 10-2016-0090977 Patent Document 2: Japanese Patent No. 5633228

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

The present invention provides a laminate as shown below.

［1］　A stretchable laminate comprising a substrate layer and a polarizing layer, wherein the moisture content of the substrate layer is 5.0% or less and satisfies the following equation (1).

｜E _A －E _T ｜／｜E _A ＋E _T ｜≤0.25 (1)

[In the formula, E _A and E _T represent the tensile moduli in the absorption axis direction and the transmission axis direction, respectively.]

［2］　A laminate as described in [1], having an overall haze value of 3% or less.

［3］　A laminate as described in [1] or [2], wherein the thickness of the polarizing layer is 0.5 ㎛ to 10 ㎛.

［4］　A 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.

［5］　A 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 per 100 parts by mass of the polymerizable liquid crystal compound.

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

［7］　A laminate as described in ［6] having a phase difference layer laminated through the above-mentioned adhesive layer.

［8］　A display device in which a laminate described in any one of ［1］ to ［7］ is bonded to an image display element.

According to one embodiment of the present invention, it is possible to provide a stretchable laminate in which, even when stretched, the optical characteristics of the visibility-corrected single transmittance or the visibility-corrected polarization degree do not change significantly, and also in which no appearance defects such as haze or cracks occur.

Figure 1 shows a schematic cross-sectional view of a laminate related to one embodiment of the present invention.

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

＜Laminated Body＞

Fig. 1 shows a schematic cross-sectional view of a laminate related to one embodiment of the present invention. The laminate (10) is a stretchable laminate composed of a substrate layer (11) and a polarizing layer (12). Being stretchable means that the laminate (10) can be stretched without breaking when pulled in at least one of the absorption axis direction and the transmission axis direction. The absorption axis direction means the orientation direction of the dichroic dye and the polymerizable liquid crystal compound that constitute the polarizing layer (12) when the polymerizable liquid crystal compound is cured in a state in which the dichroic dye and the polymerizable liquid crystal compound are horizontally aligned with respect to the substrate layer plane, or when the dichroic dye exhibiting liquid crystal properties is horizontally aligned with respect to the substrate layer plane. The direction of the transmission axis refers to a direction that is horizontal to the substrate layer plane and also perpendicular to the orientation direction when the polymerizable liquid crystal compound and the dichroic dye that constitutes the polarizing layer (12) are cured in a state in which they are horizontally aligned with respect to the substrate layer plane, or when the dichroic dye exhibiting liquid crystal properties is horizontally aligned with respect to the substrate layer plane. The orientation state of the polarizing layer can be confirmed by observation under a polarizing microscope. A laminated sample is inserted between the cross Nicols of a polarizing microscope at a direction of about 45°, and observed under a light leakage state. When oriented vertically, no light leakage occurs and observation is made under a dark field state, and when oriented horizontally, light leakage occurs and observation is made under a bright field state.

The laminate (10) may have a fracture elongation in both the absorption axis direction and the transmission axis direction of, for example, 5% or more. When the fracture elongation in both the absorption axis direction and the transmission axis direction is 5% or more, sufficient stretchability tends to be easily obtained. The laminate (10) has a fracture elongation in both the absorption axis direction and the transmission axis direction of preferably 5% to 20%, more preferably 5% to 15%. When the fracture elongation in both the absorption axis direction and the transmission axis direction is 5% to 20%, sufficient stretchability tends to be easily obtained, and at the same time, changes in optical properties and appearance defects such as haze and cracks tend to be less likely to occur. The elongation at break in the absorption axis direction and the transmission axis direction is the elongation at which the laminate breaks when stretched in the absorption axis direction or the transmission axis direction in a tensile test, and is measured in accordance with JIS K7161, for example, using a UTM (Universal Testing Machine, Autograph AG-X, Shimadzu Corporation). The elongation at break can adopt a value at room temperature (temperature 23°C).

The laminate (10) satisfies the following equation (1) when the tensile elastic moduli in the absorption axis direction and the transmission axis direction are E _A and E _T , respectively.

｜E _A －E _T ｜／｜E _A ＋E _T ｜≤0.25 (1)

If the laminate (10) does not satisfy equation (1), when the laminate (10) is stretched, the optical properties tend to change, break, or cause appearance defects such as haze and cracks. The reason for this is that it is presumed that the optical properties of the laminate are maintained even when the laminate is stretched because the laminate has a certain degree of isotropic tensile elastic modulus. However, the present invention is not limited to this presumption in any way. The tensile elastic modulus can be measured according to the measurement method described in the Examples section below. The lower limit of ｜E _A - E _T ｜/｜E _A + E _T ｜ may 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, for example, adjusting the thickness of the substrate layer (11), the polarizing layer (12), and the alignment layer, selecting the material used for the substrate layer, selecting a dichroic dye or a polymerizable liquid crystal compound for forming the polarizing layer or adjusting the composition ratio thereof, selecting the raw material used for the composition for forming the alignment layer and adjusting the composition ratio, and adjusting the conditions for forming the polarizing layer and the alignment layer, for example, applying conditions, drying conditions, and polymerization conditions, so as to satisfy equation (1). In particular, since the tensile elastic modulus of the laminate is related to the tensile elastic modulus of the substrate layer, it is preferable to use a substrate layer having an elongation of 5% or more.

The laminate (10) preferably satisfies the following equation (2).

｜E _A －E _T ｜／｜E _A ＋E _T ｜≤0.20 (2)

The tensile moduli E _A and E _T may both be, for example, 1 MPa to 30,000 MPa, preferably 10 MPa to 20,000 MPa, more preferably 50 MPa to 15,000 MPa, and may also be 1,000 MPa to 7,000 MPa, or even 1,000 MPa to 5,000 MPa. When the tensile moduli E _A and E _T are both 50 MPa to 15,000 MPa, the laminate (10) tends to be difficult to break even when stretched.

The laminate (10) may have an overall haze value of, for example, 3% or less. When the overall haze value is 3% or less, it can be suitably used in a display device. The laminate (10) preferably has an overall haze value of 2.8% or less, more preferably 2.5% or less. When the overall haze value is 3% or less, when the laminate (10) is used in a display device, visibility tends to be easily improved. The overall haze value can be measured according to the method described in the Examples section described below. Meanwhile, the overall haze value is usually 0.1% or more. The overall haze value can be measured according to the measuring method described in the Examples section described below.

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

The polarization performance of the laminate (10) can be measured using a spectrophotometer. For example, in the range of visible light wavelengths of 380 nm to 780 nm, the transmittance (T1) in the transmission axis direction (the direction perpendicular to the orientation direction of the dichroic dye) and the transmittance (T2) in the absorption axis direction (the same direction as the orientation direction of the dichroic dye) can be measured by the double beam method using a device in which a holder having a polarizer is set in a spectrophotometer. The polarization performance in the visible light range can be calculated by calculating the single transmittance and polarization degree at each wavelength using the following equations (3) and (4), and further calculating the visibility-corrected single transmittance (Ty) and the visibility-corrected polarization degree (Py) by performing visibility correction using a 2-degree field of view (C light source) of JIS Z 8701.

Group penetration rate (%) = (T1 + T2) / 2 Equation (3)

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

The laminate (10) may have a visibility correction group transmittance of, for example, 30% or more, preferably 35% or more, and more preferably 38% or more. On the other hand, the laminate (10) has a visibility correction group transmittance of, for example, 70% or less, preferably 48% or less, and more preferably 46% or less. The visibility correction group transmittance can be measured according to the method described in the Examples section described below.

In the laminate (10), the difference (ΔT) in the visibility-corrected unit transmittance before and after stretching in the absorption axis direction and the transmission axis direction may both be, for example, 1.5% or less, preferably 1.2% or less, more preferably 1% or less. In a preferred embodiment, the laminate (10) may both be, for example, 1.5% or less, preferably 1.2% or less, more preferably 1% or less, in the visibility-corrected unit transmittance before stretching and after 5% stretching in the absorption axis direction and the transmission axis direction. In a more preferred embodiment, the laminate (10) may both be, for example, 1.5% or less, preferably 1.2% or less, more preferably 1% or less, in the visibility-corrected unit transmittance value before stretching and after 10% stretching in the absorption axis direction and the transmission axis direction.

The laminate (10) may have a visibility correction polarization degree of, for example, 80% or more, preferably 85% or more, and more preferably 90% or more. Meanwhile, the laminate (10) may have a visibility correction polarization degree of, for example, 100% or less, may be 99.99% or less, and may be 99.0% or less. The visibility correction polarization degree can be measured according to the method described in the Examples section described below.

In the laminate (10), the difference (ΔP) in the polarization degree corrected for visibility before and after stretching in the absorption axis direction and the transmission axis direction may both be, for example, 3% or less, preferably 2.5% or less, more preferably 2% or less. In a preferred embodiment, the difference (ΔP) in the polarization degree corrected for visibility before and after stretching 5% in the absorption axis direction and the transmission axis direction may both be, for example, 3% or less, preferably 2.5% or less, more preferably 2% or less. In a more preferred embodiment, the difference (ΔP) in the polarization degree corrected for visibility before and after stretching 10% in the absorption axis direction and the transmission axis direction may both be, for example, 3% or less, preferably 2.5% or less, more preferably 2% or less.

The laminate (10) may have a thickness of, 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, there is a tendency for the display device to be made thinner.

Below, each layer constituting the laminate (10) is described.

[Description layer]

The substrate layer (11) may be composed of, for example, a resin film, and preferably may be composed of a transparent resin film. The resin film may be a long roll-shaped resin film or a sheet-shaped resin film. A long roll-shaped resin film is preferable because it can be manufactured continuously.

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

Representative examples of commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona, Germany), "ARTON" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (all manufactured by ZEON CORPORATION), and "APEL" (registered trademark) (manufactured by Mitsui Chemicals Inc.). These cyclic olefin resins can be formed into a resin film by a known means such as a solvent casting method or a melt extrusion method. A commercially available cyclic olefin resin film can also be used. Representative examples of commercially available products of cyclic olefin resin films include "Essina" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Company, Limited), "Zeonoa Film" (registered trademark) (manufactured by Optes Inc.), and "Aton Film" (registered trademark) (manufactured by JSR Co., Ltd.).

Representative examples of commercially available resin films composed of cellulose esters include "FUJITAC Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY", and "KC4UY" (all manufactured by Konica Minolta Opto Co., Ltd.).

The moisture content of the substrate layer (11) is 5.0% or less, and 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 forming the polarizing layer (12), the uniformity of the alignment direction of the polymerizable liquid crystal compound and the dichroic dye tends to increase. In particular, when the laminate (10) is stretched, the unevenness of the optical characteristics is easily recognized, and as a result, the polarizing layer is likely to maintain good optical characteristics even after stretching. The moisture content of the substrate layer is measured by the method described in the examples described below.

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

The substrate layer (11) may have a hard coat layer, an antireflection layer, or an antistatic layer on at least one surface. The substrate layer (11) may have a hard coat layer, an antireflection layer, or an antistatic layer formed only on the surface on which the polarizing layer (12) is not formed. The substrate layer (11) may have a hard coat layer, an antireflection layer, or an antistatic layer formed only on the surface on which the polarizing layer (12) is formed. A window film described later may also be used as the substrate layer (11).

[Polarization layer]

The polarizing layer (12) is preferably a layer composed of a cured product of a composition containing one or more types of polymerizable liquid crystal compounds [hereinafter also referred to as polymerizable liquid crystal (a)] and a dichroic dye, or a layer composed of a cured product of a composition containing one or more types of dichroic dyes exhibiting liquid crystal properties. When the polarizing layer (12) has polarization characteristics in the plane direction of the laminate (10), it is preferable that the polymerizable liquid crystal (a) be cured in a state where the dichroic dye and the polymerizable liquid crystal (a) are horizontally aligned with respect to the plane of the laminate (10), or the dichroic dye exhibiting liquid crystal properties with respect to the plane of the laminate (10) is horizontally aligned. When the polarizing layer (12) has polarization characteristics in the thickness direction of the laminate (10), it is preferable that the polymerizable liquid crystal (a) be cured in a state where the dichroic dye and the polymerizable liquid crystal (a) are vertically aligned with respect to the plane of the laminate (10), or the dichroic dye exhibiting liquid crystal properties with respect to the plane of the laminate (10) is vertically aligned. The polarizing layer (12) is preferably a coating layer, and may be, for example, a cured product of a polarizing layer-forming composition containing one or more types of polymerizable liquid crystal (a) and a dichroic dye [hereinafter also referred to as composition (A)].

The polarizing layer (12) may have a thickness of, for example, 0.5 to 10 ㎛, preferably 1 to 8 ㎛, and more preferably 1.5 to 5 ㎛.

The polarizing layer (12) can be formed, for example, by applying the composition (A) onto the substrate layer (11) or the alignment layer described below and polymerizing the polymerizable liquid crystal (a) in the resulting coating film.

(polymerizable liquid crystal)

The polymerizable liquid crystal (a) is a compound having a polymerizable group and also having liquid crystal properties. The polymerizable group means a group involved in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group that can participate in a polymerization reaction by an active radical or an acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, an oxetanyl group, and the like. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystal properties may be either a thermotropic liquid crystal or a lyotropic liquid crystal, but when mixed with a dichroic dye described later, a thermotropic liquid crystal is preferable.

When the polymerizable liquid crystal (a) is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase, or it may be a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. When expressing a polarizing function as a cured film by a polymerization reaction, the liquid crystal state exhibited by the polymerizable liquid crystal (a) is preferably a smectic phase, and a higher-order smectic phase is more preferable from the viewpoint of high performance. Among these, a higher-order smectic liquid crystal compound forming a Smectic B phase, Smectic D phase, Smectic E phase, Smectic F phase, Smectic G phase, Smectic H phase, Smectic I phase, Smectic J phase, Smectic K phase, or Smectic L phase is more preferable, and a higher-order smectic liquid crystal compound forming a Smectic B phase, Smectic F phase, or Smectic I phase is still more preferable. When the liquid crystal phase formed by the polymerizable liquid crystal (a) is these higher-order smectic phases, a polarizing layer having higher polarizing performance can be manufactured. In addition, such a polarizing layer with high polarization performance obtains a Bragg peak derived from a high-order structure of a hexahedral phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from a periodic structure of molecular orientation, and a film having a periodic interval of 3 to 6 Å can be obtained. The polarizing layer of the present invention preferably includes a polymer of a polymerizable liquid crystal (a) in which the polymerizable liquid crystal (a) is polymerized in a smectic phase from the viewpoint of obtaining higher polarization characteristics.

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

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, a 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. A carbon atom 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. However, 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 of each other, single bonds or divalent linking groups.

V ¹ and V ² independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent. -CH ₂ - constituting the alkanediyl group may be substituted with -O-, -S- or -NH-.

U ¹ and U ² 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 a 1,4-phenylene group which may optionally have a substituent, or a cyclohexane-1,4-diyl group which may optionally have a substituent. In particular, X ¹ and X ³ are preferably a cyclohexane-1,4-diyl group which may optionally have a substituent, and the cyclohexane-1,4-diyl group is more preferably a trans-cyclohexane-1,4-diyl group. When compound (I) includes a trans-cyclohexane-1,4-diyl group, smectic liquid crystal properties tend to be easily exhibited. In addition, the 1,4-phenylene group which may optionally have a substituent, or the cyclohexane-1,4-diyl group which may optionally have a substituent, may optionally have a substituent, for example, an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, and a butyl group, a cyano group, and a halogen atom, such as a chlorine atom or a fluorine atom. The 1,4-phenylene group or the cyclohexane-1,4-diyl group is preferably unsubstituted.

Y ¹ and Y ² are preferably, independently of each other, a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a =CR ^b -, -C≡C- or -CR ^a =N-, and R ^a and R ^b independently of each other represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. It is more preferable that Y ¹ and Y ² are -CH ₂ CH ₂ -, -COO-, -OCO- or a single bond, and when X ¹ , X ² and X ³ do not all contain a cyclohexane-1,4-diyl group, it is more preferable that Y ¹ and Y ² have different bonding modes. When Y ¹ and Y ² have different bonding modes, smectic liquid crystallinity tends to easily develop.

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

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, and a dicosane-1,20-diyl group. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably, they are linear alkanediyl groups having 6 to 12 carbon atoms. By using an alkanediyl group with 6 to 12 carbon atoms in a straight chain, crystallinity is improved, and there is a tendency for smectic liquid crystal properties to be easily expressed.

The alkanediyl group having 1 to 20 carbon atoms which may optionally have a substituent may optionally have a cyano group and a halogen atom such as a chlorine atom or a fluorine atom. The alkanediyl group is preferably unsubstituted, and is more preferably unsubstituted and a straight-chain alkanediyl group.

It is preferable that both U ¹ and U ² are polymerizable groups, and it is more preferable that both are photopolymerizable groups. A polymerizable liquid crystal compound having a photopolymerizable group can be polymerized under lower temperature conditions than a polymerizable liquid crystal compound having a thermal polymerizable group, and thus is advantageous in that the liquid crystal can form a polymer in a state of higher order.

The polymerizable groups represented by U ¹ and U ² may be different from each other, but are preferably the same. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and a methacryloyloxy group or an acryloyloxy group is more preferable.

Examples of such polymerizable liquid crystal compounds include the following:

[Fire 1]

[Fire 2]

[Fire 3]

[Fire 4]

Among the compounds exemplified above, 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 preferable.

(Dichromatic pigment)

A dichroic dye is a pigment having different absorbances in the long axis direction and the short axis direction of the molecule. As a dichroic dye, it is preferable to have a characteristic of absorbing visible light, and it is more preferable to have an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes. Among them, an azo dye is preferable as a dichroic dye. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbenazo dyes, and bisazo dyes and trisazo dyes are preferable. A dichroic dye may be used alone or in combination. In order to obtain absorption across the entire visible spectrum, it is preferable to use a combination of three or more types of dichroic dyes, and it is more preferable to use a combination of three or more types of azo dyes.

As an azo dye, for example, a compound represented by formula (II) (hereinafter also referred to as “compound (II)”) can be mentioned.

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

[In formula (II),

A ¹ and A ² and A ³ independently represent a 1,4-phenylene group which may have a substituent, a naphthalene-1,4-diyl group, or a divalent heterocyclic group which may have a substituent. T ¹ and T ² are electron withdrawing groups or electron releasing groups and are located at positions substantially 180° with respect to the azo bond plane. p represents an integer from 0 to 4. When p is 2 or more, each A ² may be the same or different. In a range showing absorption in the visible region, the -N=N- bond may be replaced by a -C=C-, -COO-, -NHCO-, or -N=CH- bond.］

The substituents optionally possessed by the 1,4-phenylene group, the naphthalene-1,4-diyl group and the divalent heterocyclic group in A ¹ , A ² and A ³ include: an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; a halogen atom such as a chlorine atom and a fluorine atom; Examples of substituted or unsubstituted amino groups include amino groups, diethylamino groups, and pyrrolidino groups (a substituted amino group means an amino group having one or two 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. An unsubstituted amino group is -NH ₂ .) In addition, examples of alkyl groups having 1 to 6 carbon atoms include a methyl group, an ethyl group, and a hexyl group. Examples of the alkanediyl group having 2 to 8 carbon atoms include 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, and octane-1,8-diyl. In order to be incorporated into a high-order liquid crystal structure such as a smectic liquid crystal, A ¹ and A ² and A ³ are preferably unsubstituted or a 1,4-phenylene group in which hydrogen is substituted with a methyl group or a methoxy group, or a divalent heterocyclic group, and p is preferably 0 or 1. Among these, a molecule in which p is 1 and at least two of the three structures of A ¹ , A ^2, and A ³ are 1,4-phenylene groups is more preferable in terms of both simplicity of molecular synthesis and high performance.

As a divalent heterocyclic group, groups in which two hydrogen atoms are removed from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzoimidazole, oxazole, and benzoxazole can be mentioned. When A ² is a divalent heterocyclic group, a structure in which the molecular bond angle is substantially 180° is preferable, and specifically, a structure of benzothiazole, benzoimidazole, or benzoxazole in which two five-membered rings are condensed is more preferable.

T ¹ and T ² are electron withdrawing groups or electron releasing groups, and it is preferable that they have different structures, and a combination in which T ¹ is an electron withdrawing group and T ² is an electron releasing group, or a combination in which T ¹ is an electron withdrawing group and T ² is an electron releasing group, is more preferable. Specifically, it is preferable that T ¹ and T ² independently represent 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 to 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 incorporated into a highly ordered liquid crystal structure such as a smectic liquid crystal, a structure with a smaller excluded volume of molecules is required. Therefore, it is preferable that T ¹ and T ² independently represent 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 to 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:

[Fire 5]

[Fire 6]

Among equations (2-1) to (2-6),

B ¹ to B ²⁰ independently represent 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 definitions of a substituted amino group and an unsubstituted amino group are as described 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 a hydrogen atom is more preferable.

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

When n1 is 2 or more, the plurality of B ² may be the same or different, when n2 is 2 or more, the plurality of B ⁶ may be the same or different, when n3 is 2 or more, the plurality of B ⁹ may be the same or different, and when n4 is 2 or more, the plurality of B ¹⁴ may be the same or different.

As the above anthraquinone pigment, a compound represented by formula (2-7) is preferable.

[Tuesday 7]

[In Equation (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.

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

As the above oxazine pigment, a compound represented by formula (2-8) is preferable.

[Tuesday 8]

[In Equation (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.

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

As the above acridine pigment, a compound represented by formula (2-9) is preferable.

[Tuesday 9]

[In Equation (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.

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

In formulas (2-7), (2-8), and (2-9), examples of the alkyl group having 1 to 4 carbon atoms represented by R ^x include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

As the above cyanine pigment, a compound represented by formula (2-10) and a compound represented by formula (2-11) are preferable.

[Tue 10]

[In Equation (2-10),

D ¹ and D ² independently represent a group represented by any one of formulas (2-10a) to (2-10d).

[Tue 11]

n5 represents an integer from 1 to 3.]

[Tue 12]

[In Equation (2-11),

D ³ and D ⁴ independently represent a group represented by any one of formulas (2-11a) to (2-11h).

[Tue 13]

n6 represents an integer from 1 to 3.]

The content of the dichroic dye (the total amount when multiple types are included) is, from the viewpoint of obtaining good light absorption characteristics, usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 2 to 15 parts by mass, per 100 parts by mass of the polymerizable liquid crystal (a). If the content of the dichroic dye is less than this range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained, and if it is more than this range, the alignment of the liquid crystal molecules may be inhibited.

(orientation layer)

The laminate (10) may have an alignment layer between the substrate layer (11) and the polarizing layer (12). The alignment layer has an alignment control power that aligns the polymerizable liquid crystal forming the polarizing layer (12) formed on the substrate layer (11) in a desired direction.

The alignment layer facilitates the alignment of the polymerizable liquid crystal. The alignment state of the liquid crystal, such as horizontal alignment, vertical alignment, hybrid alignment, and inclined alignment, varies depending on the properties of the alignment layer and the polymerizable liquid crystal, and the combination thereof can be arbitrarily selected. For example, if the alignment layer is a material that exhibits horizontal alignment as an alignment control force, the polymerizable liquid crystal can form horizontal alignment or hybrid alignment, and if it is a material that exhibits vertical alignment, the polymerizable liquid crystal can form vertical alignment or inclined alignment. The expressions horizontal, vertical, etc. indicate the direction of the major axis of the aligned polymerizable liquid crystal with respect to the plane of the polarizing layer (12). For example, vertical alignment means that the major axis of the aligned polymerizable liquid crystal is oriented in a direction perpendicular to the plane of the polarizing layer (12). Here, vertical means 90°±20° with respect to the plane of the polarizing layer (12).

The orientation control force can be arbitrarily adjusted according to the surface state or rubbing conditions when the orientation layer is formed of an orientation polymer, and can be arbitrarily adjusted according to polarization irradiation conditions, etc. when it is formed of a photo-orientable polymer. In addition, the liquid crystal orientation can also be controlled by selecting the physical properties of the polymerizable liquid crystal compound, such as surface tension or liquid crystallinity.

The alignment layer formed between the substrate layer (11) and the polarizing layer (12) is preferably insoluble in the solvent used when forming the polarizing layer (12) on the alignment layer, and also has heat resistance in the heat treatment for removal of the solvent or alignment of the liquid crystal. The alignment layer may be an alignment layer, a photoalignment layer, a groove alignment layer, or the like made of an alignment polymer. Among these, a photoalignment layer is preferable in that the alignment direction can be easily controlled when applied to a long roll-shaped resin film.

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.

As the orienting polymer used in the orientation layer composed of the orienting polymer, examples thereof include polyamides and gelatins having amide bonds in the molecule, polyimides having imide bonds in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinyl pyrrolidone, polyacrylic acid, and polyacrylic acid esters. Among these, polyvinyl alcohol is preferable as the orienting polymer. These orienting polymers may be used alone or in combination of two or more.

When forming an orientation layer made of an orienting polymer on a substrate layer made of a resin film, the orientation layer made of the orienting polymer is usually obtained by applying a composition in which the orienting polymer is dissolved in a solvent (hereinafter also referred to as an “orienting polymer composition”) to a resin film and removing the solvent, or applying an orienting polymer composition to a resin film, removing the solvent, and rubbing (rubbing method).

Examples of the solvent include: water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, 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, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxy ethane; chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene; These solvents may be used alone or in combination of two or more.

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

As an orientation polymer composition, a commercially available orientation layer forming material may be used as is. Examples of commercially available orientation layer forming materials include SUNEVER (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.) or Optoma (registered trademark) (manufactured by JSR Corporation).

As a method for applying the oriented polymer composition to a resin film, known methods such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, and an applicator method, and a printing method such as a flexographic method can be exemplified. When the laminate of the present invention is produced by a continuous production method in a roll-to-roll format, a gravure coating method, a die coating method, or a printing method such as a flexographic method is usually employed as the coating method.

By removing the solvent included in the orientation polymer composition, a dry film of the orientation polymer is formed. Examples of methods for removing the solvent include a natural drying method, a ventilation drying method, a heat drying method, and a reduced pressure drying method.

As a method of rubbing, a method of bringing a film of an oriented polymer into contact with a rubbing roll can be exemplified. The rubbing roll is a roll that can rotate while the rubbing cloth is wound around it.

The photoalignment layer is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter also referred to as a “photoalignment layer forming composition”) to a resin film and irradiating it with polarized light (preferably polarized UV). The photoalignment layer is more preferable in that the direction of the alignment control force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group refers to a group that causes liquid crystal alignment ability by irradiating light. Specifically, it is a group that causes a photoreaction that becomes the origin of liquid crystal alignment ability, such as molecular alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction caused by irradiating light. Among the above photoreactive groups, those that cause a dimerization reaction or photocrosslinking reaction are preferable in that they have excellent alignment properties. As a photoreactive group that can cause the above reaction, those having an unsaturated bond, particularly a double bond, are preferable, and a group having at least one selected from the group consisting of 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) is more preferable.

As a photoreactive group having a C=C bond, examples thereof include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. From the viewpoints of easy control of reactivity and expression of orientation regulation power during photoalignment, a chalcone group and a cinnamoyl group are preferable. As a photoreactive group having a C=N bond, examples thereof include groups having structures such as an aromatic Schiff base and an aromatic hydrazone. As a photoreactive group having an N=N bond, examples thereof include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and the like, as well as those having azoxybenzene as a basic structure. As a photoreactive group having a C=O bond, examples thereof include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group. Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group are preferable because a photoalignment layer with a relatively small amount of polarized light irradiation required for photoalignment and excellent heat stability and time stability can be easily obtained. As a polymer having a photoreactive group, one having a cinnamoyl group in which the terminal portion of the polymer side chain forms a cinnamic acid structure is particularly preferable.

In view of the ease of handling of the composition for forming the above-mentioned photoalignment layer and the ease of obtaining an alignment layer realizing high-durability alignment, a polymer having a photoreactive group is particularly preferable, for example, a polymer having a group represented by formula (A') in a side chain (hereinafter, sometimes also referred to as "polymer (A')").

[Tue 14]

[In formula (A'),

n represents 0 or 1.

X ¹ represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, or -CH ₂ -.

Y ¹ represents a single bond or -O-.

R ¹ and R ² 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 a bond to the polymer backbone.

In formula (A'), X ¹ is particularly preferable if it is any one of a single bond, -O-, -COO-, -OCO-, -N=N-, -C=C-, and -CH ₂ -, because this facilitates the production of the polymer (A') itself.

In formula (A'), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, a halogenated alkyl group, a halogenated alkoxy 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 hydroxy group, and the carboxyl group and the sulfonic acid group may form a salt with an alkali metal ion. Among these, it is more preferable if R ¹ and R ² 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. 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 backbone of the polymer (A') is not particularly limited, but it is preferable that the polymer (A) has a backbone composed of a unit selected from the group consisting of a (meth)acrylic acid ester unit represented by formula (M-1) or formula (M-2); a (meth)acrylamide unit represented by formula (M-3) or formula (M-4); a vinyl ether unit represented by formula (M-5) or formula (M-6); a (methyl)styrene unit represented by formula (M-7) or formula (M-8), and a vinyl ester unit represented by formula (M-9) or formula (M-10), and among these, it is more preferable that the polymer (A') has a backbone composed of a unit selected from the group consisting of a (meth)acrylic acid ester unit and a (meth)acrylamide unit. In addition, the "backbone of the polymer (A')" as mentioned here means the longest molecular chain among the molecular chains possessed by the polymer (A').

[Tue 15]

The unit represented by any one of formulas (M-1) to (M-10) and the group represented by formula (A') may be directly bonded or may be bonded via an appropriate linking group. Examples of the linking group include a carbonyloxy group (ester bond), an oxygen atom (ether bond), an imide group, a carbonylimino group (amide bond), an iminocarbonylimino group (urethane bond), a divalent aliphatic hydrocarbon group which may have a substituent, a divalent aromatic hydrocarbon group which may have a substituent, and a divalent group formed by combining these. Specific examples of the divalent aromatic hydrocarbon group which may have a substituent include a phenylene group, a 2-methoxy-1,4-phenylene group, a 3-methoxy-1,4-phenylene group, a 2-ethoxy-1,4-phenylene group, a 3-ethoxy-1,4-phenylene group, a 2,3,5-trimethoxy-1,4-phenylene group, etc. Among these, the connecting group is preferably an aliphatic hydrocarbon group, and an alkanediyl group having 1 to 11 carbon atoms which may have a substituent is more preferable. In addition, such alkanediyl groups include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, and an undecamethylene group, and these may be linear or branched. In addition, such alkanediyl groups may have a substituent. The substituent is, for example, an alkoxy group having 1 to 4 carbon atoms.

In other words, as a structural unit having a group represented by formula (A'), the one represented by formula (A) (hereinafter, in some cases, it is also called "structural unit (A)", and a polymer including the structural unit (A) is also called "polymer (A)") is preferable.

[Tue 16]

[In formula (A),

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

S ¹ is an alkanediyl group having 1 to 11 carbon atoms,

[Tue 17]

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

The molecular weight of the polymer (A') or polymer (A) is expressed as a weight average molecular weight in terms of polystyrene obtained, for example, by a gel permeation chromatography (GPC) method, and is preferably in the range of 1×10 ³ to 1×10 ⁷ . However, if the molecular weight is too high, the solubility in a solvent decreases, making it difficult to prepare a composition for forming an alignment layer, or the sensitivity to light irradiation tends to decrease, so the range of 1×10 ⁴ to 1×10 ⁶ is preferably.

In addition to the structural unit (A), the polymer (A) may have a structural unit represented by the formula (B) (hereinafter, sometimes referred to as “structural unit (B)”).

[Tue 18]

[In formula (B),

m represents 0 or 1.

S ² represents an alkanediyl group having 1 to 11 carbon atoms.

[Tue 19]

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

X ² represents a single bond, -O-, -COO-, -OCO-, -N=N-, -CH=CH-, or -CH ₂ -.

Y ² represents a single bond or -O-.

R ³ and R ⁴ 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 S ² are the same as the specific examples of S ¹ in formula (A), and specific examples of the alkyl group and alkoxy group of R ³ and R ⁴ are the same as the specific examples of R ¹ and R ² in formula (A), respectively.

When the mole fractions of the structural unit (A) and the structural unit (B) with respect to the total structural unit of the polymer (A) are respectively p and q (p＋q is 1), it is preferable to satisfy the relationships 0.25＜p≤1 and 0≤q＜0.75. [Here, when the polymer (A) has the structural unit (A) and p is 1, it 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.]. However, the polymer (A) may have structural units other than the structural unit (A) and the structural unit (B) (hereinafter, also referred to as “other structural units” in some cases) as long as the orientation ability due to light irradiation is not significantly impaired.

Polymer (A) can be produced by polymerizing or copolymerizing a monomer that induces a structural unit (A) and, if necessary, a monomer that induces a structural unit (B) or another structural unit. An addition polymerization method is usually employed for the polymerization or copolymerization. Examples of such addition polymerization include radical polymerization, chain polymerization such as anionic polymerization and cationic polymerization, and coordination polymerization. Polymerization conditions are set so that the above-described preferable molecular weight of the polymer (A) is satisfied, depending on the type and amount of the monomer used.

Above, although the polymer (A) is preferable among the polymers having a photoreactive group, the composition for forming an alignment layer is prepared by dissolving the polymer having the photoreactive group (preferably, the polymer (A)) in an appropriate solvent. This solvent can be appropriately selected within a range in which the polymer having the photoreactive group can be dissolved, so that an alignment layer forming composition having an appropriate viscosity can be obtained. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, 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; Examples thereof include 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; and amide solvents such as N-methyl pyrrolidone, N,N-dimethyl formamide, γ-butyrolactone, and dimethylacetamide. These solvents may be used alone or in combination of two or more.

The content of a polymer or monomer having a photoreactive group in the composition for forming a photoalignment layer can be appropriately adjusted depending on the type of the polymer or monomer having the photoreactive group or the thickness of the photoalignment layer to be produced, but is preferably 0.2 mass% or more, and particularly preferably 0.3 to 10 mass%. In addition, a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer may be included within a range in which the properties of the photoalignment layer are not significantly impaired.

As a method for applying the composition for forming a light-aligning layer to a resin film, a method similar to the method for applying the aforementioned orientation polymer composition to a resin film can be exemplified. As a method for removing a solvent from the applied composition for forming a light-aligning layer, a method similar to the method for removing a solvent from an orientation polymer composition can be exemplified.

In order to investigate polarization, it may be a form in which polarization is directly irradiated to a composition for forming a photo-alignment layer applied on a resin film or the like after removing the solvent, or it may be a form in which polarization is irradiated to the resin film side and the polarization is transmitted therethrough. In addition, it is particularly preferable that the polarization is substantially parallel light. It is preferable that the wavelength of the polarization to be irradiated is a wavelength range in which the photo-reactive group of the polymer or monomer having the photo-reactive group can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250 nm to 400 nm is particularly preferable. As a light source used for the polarization irradiation, a xenon lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an ultraviolet laser such as KrF or ArF, and a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a metal halide lamp are more preferable. Such lamps are preferable because the emission intensity of ultraviolet light having a wavelength of 313 nm is large. Polarization can be investigated by irradiating light from the above light source through an appropriate polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan Taylor, or a wire grid type polarizer can be used.

In addition, when performing a rubbing or polarizing investigation, if masking is performed, multiple areas (patterns) with different liquid crystal alignment directions can be formed.

A grooved alignment layer is a film having a rough pattern or multiple grooves on the film surface. When liquid crystal molecules are placed on a film having multiple straight grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction of the grooves.

Examples of methods for obtaining a grooved alignment layer include a method in which a photosensitive polyimide film surface is exposed to light through an exposure mask having patterned slits, and then development and rinsing are performed to form an uneven pattern; a method in which a layer of a UV-curable resin before curing is formed on a plate-shaped disc having grooves on the surface, the resin layer is transferred to a resin film, and then cured; and a method in which a roll-shaped disc having a plurality of grooves is pressed against a UV-curable resin film formed on a resin film before curing to form unevenness, and then curing. Specific examples thereof include the methods described in Japanese Patent Application Laid-Open No. 6-34976 and Japanese Patent Application Laid-Open No. 2011-242743.

In order to obtain an orientation with small orientation disorder, the width of the convex portion of the groove alignment 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 of the unevenness is preferably 2 µm or less, and preferably 0.01 µm to 1 µm or less.

(Other floors)

The laminate (10) may further have an adhesive layer on the polarizing layer (12) side. The adhesive layer is used to bond the laminate (10) to an image display element, window film, or touch sensor of a display device, or to laminate a phase difference layer and the 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, or the like can be used.

The laminate (10) may have a phase difference layer. As the phase difference layer, 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 combinations thereof can be mentioned. As the combination of phase difference layers, 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 can be mentioned. The phase difference layer can be produced from a transparent resin film forming the above-mentioned base layer, or a composition containing a polymerizable liquid crystal compound. The phase difference layer can be produced by applying a composition containing a polymerizable liquid crystal compound onto an alignment 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 may be a layer further containing an alignment film and a base. For the production of the phase difference layer, for example, the polymerizable liquid crystal compound exemplified in the description of the polarizing layer (12) described above, the polymerizable liquid crystal compound described in Japanese Patent Application Laid-Open No. 2010-31223 or Japanese Patent Application Laid-Open No. 2009-173893, etc. can be used. The alignment film included in the phase difference layer may be, for example, the alignment film exemplified in the description of the polarizing layer (12) described above. The substrate included in the phase difference layer may be, for example, the resin film exemplified in the description of the substrate layer (11) described above. The phase difference layer can be laminated via the adhesive layer described above.

The laminate (10) may have a surface treatment layer (coating layer) such as a hard coat layer, an anti-glare layer, an anti-reflection layer, an anti-static layer, or an anti-fouling layer.

The laminate (10) may have a window film or a light-blocking pattern (bezel) arranged on the viewing side based on the polarizing layer (12). The window film is formed by including a hard coat layer on at least one surface of the transparent substrate layer. The window film is not rigid like conventional glass, but has flexible characteristics. The wiring of the display device can be hidden by the light-blocking pattern so that it is not visible to the user. The laminate (10) may be laminated on a touch sensor.

＜Laminated body manufacturing method＞

The polarizing layer (12) can be formed by applying a composition (A) on the substrate layer (11) and, if present, the alignment layer. In addition to the above-described dichroic dye and polymerizable liquid crystal compound, the composition (A) further includes a polymerization initiator, a leveling agent, and a solvent, and may further include a photosensitizer, a polymerization inhibitor, a leveling agent, and the like.

(Polymerization initiator)

A polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal, etc. From the viewpoint of not depending on the state of a thermotropic liquid crystal phase, a photopolymerization initiator that generates active radicals by the action of light is preferable as a polymerization initiator.

Examples of polymerization initiators include benzoin compounds, benzophenone compounds, alkylphenone compounds, acyl phosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

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

Examples of benzophenone compounds include benzophenone, o-benzoyl methyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl diphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino 1-(4-methylthio phenyl) propan-1-one, 2-benzyl-2-dimethyl amino-1-(4-morpholinophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenyl propan-1-one, 1,2-diphenyl-2,2-dimethoxy ethan-1-one, 2-hydroxy-2-methyl-1-〔4-(2-hydroxy ethoxy) phenyl〕propan-1-one, 1-hydroxy cyclohexylphenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-〔4-(1-methyl vinyl) phenyl〕propan-1-one.

Acyl phosphine oxide compounds include 2,4,6-trimethylbenzoyl diphenyl phosphine oxide and bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide.

Triazine compounds include, for example, 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-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-〔2-(5-methylfuran-2-yl)ethenyl〕-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-〔2-(furan-2-yl)ethenyl〕-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-〔2-(4-diethyl Examples thereof include 2,4-bis(trichloromethyl)-6-〔2-(3,4-dimethoxyphenyl)ethenyl〕-1,3,5-triazine and 2,4-bis(trichloromethyl)-6-〔2-(3,4-dimethoxyphenyl)ethenyl〕-1,3,5-triazine.

A commercially available polymerization initiator can be used. Commercially available polymerization initiators include IRGACURE (registered trademark) 907, 184, 651, 819, 250, and 369, 379, 127, 754, OXE01, OXE02, 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 The Dow Chemical Company); Examples thereof include ADEKA OPTOMER SP-152, N-1717, N-1919, SP-170, Adeka Arkuls NCI-831, Adeka Arkuls NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A, and TAZ-PP (manufactured by DKSH Japan K.K.); and TAZ-104 (manufactured by Sanwa Chemicals Co., Ltd.); The composition (A) may contain one type of polymerization initiator, or may contain two or more types of plural polymerization initiators according to the light source.

The content of the polymerization initiator in the composition (A) can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal. The content of the polymerization initiator is usually 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, per 100 parts by mass of the polymerizable liquid crystal. When the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal.

(increaser)

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

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 such sensitizer to be 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, per 100 parts by mass of the polymerizable liquid crystal content.

(Polymerization inhibitor)

From the viewpoint of stably proceeding with the polymerization reaction, the composition (A) may contain a polymerization inhibitor. The progress of the polymerization reaction of the polymerizable liquid crystal can be controlled by the polymerization inhibitor.

Examples of the polymerization inhibitor include radical scavengers such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butyl catechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, etc.; 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 even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the polymerizable liquid crystal content. When the content of the polymerization inhibitor is within the above range, polymerization can be performed without disturbing 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 applying the composition more flat. Examples of the leveling agent include organic modified silicone oil-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all from Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161 A, KF6001 (all from Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all from Momentive Performance Materials Japan Inc.), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Limited), MEGAFACE (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479, F-482, F-483 (all manufactured by DIC Co., Ltd.), EFTOP (trade name) EF301, EF303, EF351, EF352 (all manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Sulfone (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 (all manufactured by AGC SEIMI) Examples thereof include leveling agents such as E1830, E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353, and BYK-361 N (all trade names: BM Chemie). Among these, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferable.

When the composition (A) contains a leveling agent, the content of the leveling agent is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the content of the polymerizable liquid crystal. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal, and furthermore, the obtained polarizing layer tends to be smoother. When the content of the leveling agent with respect to the polymerizable liquid crystal exceeds the above range, the obtained polarizing layer tends to be uneven. Furthermore, the composition (A) may contain two or more types of leveling agents.

(solvent)

The composition (A) may contain a solvent. Generally, since polymerizable liquid crystal compounds have high viscosity, by dissolving the composition (A) in a solvent, application becomes easy, and as a result, formation of a polarizing layer often becomes easy. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, 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, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; Examples thereof include amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably 50 to 98 mass% with respect to the total amount of the composition (A). In other words, the content of the solid content in the composition (A) is preferably 2 to 50 mass%. When the content of the solid content is 50 mass% or less, the viscosity of the composition (A) is lowered, so that the thickness of the polarizing layer tends to be approximately uniform. As a result, there is a tendency for unevenness to occur in the polarizing layer. In addition, the content of the solid content can be determined in consideration of the thickness of the polarizing layer to be manufactured.

(reactive additive)

The composition (A) may contain a reactive additive. The reactive additive is preferably one having a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule. In addition, the "active hydrogen reactive group" mentioned here means a group which is reactive toward a group having an active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH ₂ ), and representative examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, a maleic anhydride group, and the like. The number of carbon-carbon unsaturated bonds and active hydrogen reactive groups possessed by the reactive additive is usually 1 to 20 each, and preferably 1 to 10 each.

In the reactive additive, it is preferable that at least two active hydrogen reactive groups are present, and in this case, the multiple active hydrogen reactive groups present may be the same or different.

The carbon-carbon unsaturated bond of the reactive additive may be a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, but is preferably a carbon-carbon double bond. Among these, the reactive additive is preferably a vinyl group and/or a (meth)acrylic group containing a carbon-carbon unsaturated bond. Furthermore, a reactive additive having at least one active hydrogen reactive group selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group is preferable, and a reactive additive having an acrylic group and an isocyanate group is more preferable.

Specific examples of the reactive additive include compounds having a (meth)acrylic group and an epoxy group, such as methacryloxyglycidyl ether or acryloxyglycidyl ether; compounds having a (meth)acrylic group and an oxetane group, such as oxetane acrylate or oxetane methacrylate; compounds having a (meth)acrylic group and a lactone group, such as lactone acrylate or lactone methacrylate; compounds having a vinyl group and an oxazoline group, such as vinyloxazoline or isopropenyloxazoline; oligomers of compounds having a (meth)acrylic group and an isocyanate group, such as isocyanate methyl acrylate, isocyanate methyl methacrylate, 2-isocyanate ethyl acrylate, and 2-isocyanate ethyl methacrylate. In addition, compounds having a vinyl group or a vinylene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride, etc., can be mentioned. Among them, methacryloxyglycidyl ether, acryloxyglycidyl ether, isocyanate methyl acrylate, isocyanate methyl methacrylate, vinyloxazoline, 2-isocyanate ethyl acrylate, 2-isocyanate ethyl methacrylate, and the above oligomers are preferable, and isocyanate methyl acrylate, 2-isocyanate ethyl acrylate, and the above oligomers are particularly preferable.

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

[Tue 20]

[In formula (Y),

n represents an integer from 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. The two R ² ′ in each repeating unit are groups in which one side is -NH- and the other side is represented by ＞NC(=O)-R ³ ′. R ³ ′ represents a hydroxyl group or a group having a carbon-carbon unsaturated bond.

Among R ³ ’ in formula (Y), at least one R ³ ’ is a group having a carbon-carbon unsaturated bond.]

Among the reactive additives represented by the above formula (Y), a compound represented by the following formula (YY) (hereinafter, sometimes referred to as compound (YY)) is particularly preferable (in addition, n has the same meaning as above).

[Tue 21]

For the compound (YY), a commercial product can be used as is or after being purified as needed. As a commercial product, an example is Laromer (registered trademark) LR-9000 (manufactured by BASF).

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

Before the composition (A) is applied to the substrate layer, it is preferable that the moisture content of the substrate layer be adjusted. The moisture content of the substrate layer may be 5.0% or less, and preferably 3.0% or less. The moisture content of the substrate layer (11) may be 0.0% or more. When the composition (A) is applied to the substrate layer having such a moisture content, the uniformity of the alignment direction of the polymerizable liquid crystal and the dichroic dye is improved. In particular, when the laminate (10) is stretched, the unevenness of the optical characteristics is easily recognized, and as a result, the polarizing layer is likely to maintain good optical characteristics even after stretching. The moisture content of the substrate layer is measured by the method described in the examples described below.

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

(How to apply)

Examples of methods for applying the composition (A) onto the substrate layer (11) or the alignment layer include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, a micro gravure method, a die coating method, and an inkjet method. In addition, examples include a method of applying using a coater such as a dip coater, a bar coater, and a spin coater. Among these, in the case of continuous application in a roll-to-roll format, a coating method according to a micro gravure method, an inkjet method, a slit coating method, and a die coating method is preferable, and in the case of application to a sheet such as glass, a highly uniform spin coating method is preferable. In the case of application in a roll-to-roll format, an alignment-type polymer composition or a composition for forming a photoalignment layer is applied to the substrate layer (11) to form an alignment layer, and further, the composition (A) can be continuously applied onto the obtained alignment layer.

(Drying method)

As a drying method for removing the solvent included in the composition (A), natural drying, ventilation drying, heat drying, reduced pressure drying, and a method combining these may be mentioned, for example. Of these, natural drying or heat drying is preferable. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, and even more preferably in the range of 50 to 130°C. The drying time is preferably in the range of 10 seconds to 10 minutes, and more preferably in the range of 30 seconds to 5 minutes. The composition for forming a photoalignment layer and the orientation polymer composition can also be dried in the same manner.

(Polymerization method)

As a method for polymerizing a polymerizable liquid crystal compound, photopolymerization is preferable. Photopolymerization is performed by irradiating an active energy ray to a composition (A) containing a polymerizable liquid crystal compound applied on a substrate layer (11) or an alignment layer. The active energy ray to be irradiated is appropriately selected depending on the type of the polymerizable liquid crystal compound contained in the dry film (particularly, the type of photopolymerizable functional group possessed by the polymerizable liquid crystal compound), the type of the photopolymerization initiator when a photopolymerization initiator is included, and the amount thereof. Specifically, the active energy ray may be one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and because a photopolymerization device widely used in the relevant field can be used, and it is preferable to select the type of the polymerizable liquid crystal compound so that it can be photopolymerized by ultraviolet light.

As light sources of the above active energy rays, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, LED light sources emitting in the wavelength range of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc. can be mentioned.

The intensity of ultraviolet irradiation is usually 10 mW/cm2 to 3,000 mW/cm2. The intensity of ultraviolet irradiation is preferably an intensity in a wavelength range effective for activating a cationic polymerization initiator or a radical polymerization initiator. The time for irradiating light is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and even more preferably 0.1 second to 1 minute. When irradiation is performed once or multiple times at such an intensity of ultraviolet irradiation, the accumulated light amount is, for example, 10 mJ/cm2 to 3,000 mJ/cm2, preferably 50 mJ/cm2 to 2,000 mJ/cm2, and more preferably 100 mJ/cm2 to 1,000 mJ/cm2. If the accumulated light quantity is less than this lower limit, the curing of the polymerizable liquid crystal compound may be insufficient, and good transfer properties may not be obtained. Conversely, if the accumulated light quantity exceeds this upper limit, the optical film including the optical anisotropic layer may become colored.

＜Display Device＞

The display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, a touch panel display device, an electroluminescence display device, and the like. Since the display device of the present embodiment has a stretchable laminate (10), it can be suitably used for a stretchable display device, and can be suitably used for an organic EL display device in particular.

Hereinafter, the present invention will be described in more detail by examples. “%” and “part” in the examples mean mass% and mass part, respectively, unless otherwise specified.

Example

[Tensile modulus]

The tensile modulus was measured in accordance with JIS K7161 using a UTM (Universal Testing Machine, Autograph AG-X, Shimadzu Corporation) when stretching in the absorption axis direction and the transmission axis direction respectively. The stretching conditions were room temperature (temperature 23°C), a speed of 1.5 mm/min, a width of 40 mm, and a target point distance of 50 mm.

[Total haze value]

The overall haze value of the laminate before and after stretching in each stretching direction and at each stretching ratio was measured using a haze meter (HM-150, Murakamishikisaigijutsu Research Institute) in accordance with JIS K7136. The absolute value of the difference in the overall haze value of the laminate before and after stretching at each stretching ratio was taken as ΔH.

Additionally, the overall haze value can be calculated using the following formula.

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

[Visibility Correction Group Transmittance and Visibility Correction Polarization]

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

[Moisture content of substrate layer]

The moisture content of the substrate layer was calculated using a heating and drying type moisture meter, MS-70, manufactured by A&D Company, Limited, based on the following equation. The size of the substrate layer when measuring the moisture content was 100 mm × 100 mm.

Moisture content of the substrate layer (%) = 100 × (W _A - W _B - W _P ) / (W _B - W ₂ )

W _P = W ₁ - _{W 2}

W _A is the weight of the sample dish with the substrate layer on it.

W _B is the weight when the sample dish with the substrate layer is heated at 120℃ and the change in moisture content over time becomes 0.02%/minute or less.

W ₁ is the weight of the sample dish.

W ₂ is the weight when the sample dish is heated at 120℃ and the change in moisture content over time becomes 0.02%/min or less.

W _P reflects the surface moisture content of the sample plate.

[Appearance Evaluation]

The presence or absence of unevenness, cracks, haze, and fracture in the laminate after stretching in each stretching direction and stretching ratio was visually evaluated.

○: No unevenness, no cracks, no haze, and no breakage

×: No unevenness, no cracks, no haze, and no breakage

××: Occurrence of cracks, fractures, 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)].

[Tue 22]

[Tue 23]

Compounds (1-6) and (1-7) were synthesized according to the method described in Lub et al. Rec. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

For the dichroic dye, an azo dye described in the examples of Japanese Patent Application Laid-Open No. 2013-101328, represented by the following formulae (2-1a), (2-1b), and (2-3a), was used.

[Tue 24]

[Tue 25]

[Tue 26]

[Composition for forming polarizing layer]

A composition for forming a polarizing layer was prepared by mixing 75 parts by weight of compound (1-6), 25 parts by weight of compound (1-7), 2.5 parts by weight of each of the azo dyes represented by the above formulae (2-1a), (2-1b), and (2-3a) as dichroic dyes, 6 parts by weight of 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl) butan-1-one (Irgacure369, manufactured by BASF Japan) as a polymerization initiator, and 1.2 parts by weight of a polyacrylate compound (BYK-361 N, manufactured by BYK-Chemie) as a leveling agent with 400 parts of toluene as a solvent, and stirring the obtained mixture at 80°C for 1 hour.

[Polymer 1]

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

[Tue 27]

As measured by GPC, the molecular weight of the obtained polymer 1 was a number average molecular weight of 28200, Mw/Mn of 1.82, and the monomer content was 0.5%.

[Composition for forming an orientation layer]

A solution of polymer 1 dissolved in cyclopentanone at a concentration of 5 wt% was used as a composition for forming an alignment layer.

[Example 1]

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

Next, using a UV irradiation device (SPOT CURE SP-7, manufactured by USHIO INC.), light having an accumulated light amount of 100 mJ/cm2 measured at a wavelength of 365 nm was irradiated with polarized light passing through a wire grid (UIS-27132##, manufactured by USHIO INC.) to impart alignment performance, thereby obtaining an alignment layer.

A polarizing layer-forming composition was applied onto the obtained alignment layer according to the bar coat method. The coating film was dried by heating at 100°C for 2 minutes, and then cooled to room temperature to obtain a dried film. The obtained film was irradiated with ultraviolet rays using a UV irradiation device (SPOT CURE SP-7) so that the accumulated light quantity became 1200 mJ/cm2 (based on 365 nm) to obtain a polarizing layer having a thickness of 3 μm. The tensile moduli ( _EA and _ET ) of the obtained laminate in the absorption axis direction and the transmission axis direction were measured. The laminate had an _EA of 3180 MPa and an _ET of 3900 MPa. In addition, the overall haze value, visibility-corrected single transmittance, visibility-corrected polarization degree, and appearance were evaluated before stretching, after stretching at a stretching ratio of 5% in the absorption axis direction, and after stretching at a stretching ratio of 5% in the transmission axis direction, respectively. The results are shown in Table 1. The stretching was performed using UTM. The stretching conditions were room temperature, speed 1.5 mm/min, width 40 mm, and target point distance 50 mm.

[Example 2]

In Example 1, a laminate was produced in the same manner as in Example 1, except that the elongation in the absorption axis direction and the elongation in the transmission axis direction were each set to 10%.

[Example 3]

A laminate was produced in the same manner as in Example 1, except that the substrate layer made of triacetyl cellulose (TAC) was changed to a substrate layer made of polyethylene terephthalate (PET). The thickness of the substrate layer made of PET was 50 μm. This laminate had an E _A of 4500 MPa and an E _T of 3300 MPa.

[Example 4]

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

[Comparative Example 1]

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

It was immersed 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, it was dried at 80°C to obtain a polarizing layer having a thickness of about 12 μm in which iodine was adsorbed and oriented in polyvinyl alcohol. Stretching was mainly performed through the processes of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.5 times. On one side of the obtained polarizing layer, a base layer made of a TAC film having a thickness of 25 μm (trade name "KC2UA" manufactured by Konica Minolta, Inc.) was bonded using an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin, to produce a polarizing plate. This laminate had an E _A of 8500 MPa and an E _T of 4950 MPa.

For the obtained laminate, the tensile modulus (E _A and E _T ) was measured after stretching at an elongation of 5% in the absorption axis direction and after stretching at an elongation of 5% in the transmission axis direction, respectively.

In addition, the overall haze value, visibility-corrected single transmittance, visibility-corrected polarization, and appearance were evaluated before stretching, after stretching at a stretching ratio of 5% in the absorption axis direction, and after stretching at a stretching ratio of 5% in the transmission axis direction, respectively. The results are shown in Table 1.

[Comparative Example 2]

In Comparative Example 1, a laminate was produced in the same manner as in Comparative Example 1, except that the elongation in the absorption axis direction and the elongation in the transmission axis direction were each set to 10%.

[Comparative Example 3]

A laminate was produced 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 ㎛ thick TAC film in Comparative Example 1. The PET film had a thickness of 38 ㎛. This laminate had an E _A of 9900 MPa and an E _T of 5100 MPa.

[Comparative Example 4]

A laminate was produced in the same manner as in Example 1, except that the substrate layer was not heat-dried.

As shown in Table 1, the laminates of Examples 1 to 4 had small differences in the overall haze value, visibility-corrected unit transmittance, and visibility-corrected polarization degree before and after stretching, and exhibited good appearance even after stretching. On the other hand, in Comparative Example 1, the difference in the visibility-corrected polarization degree before and after stretching was large, and sufficient results could not be obtained in the appearance evaluation after stretching. In Comparative Example 2, breakage occurred during stretching. In Comparative Example 3, the differences in the overall haze value, visibility-corrected unit transmittance, and visibility-corrected polarization degree were all large, and sufficient results could not be obtained in the appearance evaluation. In Comparative Example 4, unevenness occurred in the polarizing layer, resulting in poor appearance.

[Extension Test]

For the laminates manufactured in Examples 5 and 6 and Comparative Example 5, after reflectivity measurement was performed, the laminates were stretched at a rate of 2.5 mm/min in an environment of a temperature of 60°C and an elongation of 5% using a UTM, and then the stretched state was maintained to perform reflectivity measurement and appearance evaluation. The measurement sample of each laminate had an initial elongation direction length of 50 mm and a width of 40 mm. Elongation tests were performed for each case of stretching in the absorption axis direction (MD direction) and the transmission axis direction (TD direction).

The reflectance was measured by installing the measurement sample and the reflector (aluminum plate, reflectance 97%) in that order on a spectrophotometer (CM-2600 d, manufactured by Konica Minolta, Inc., SCI mode). The absolute value Δreflectance [%] of the difference between the reflectance [%] measured before stretching and the reflectance [%] measured while maintaining the stretching state was obtained. Δreflectance [%] can be obtained by the following equation.

ΔReflectivity［%］=｜Y(before stretching)-Y(in stretching state)｜

Y(Before stretching) = Reflectance measured before stretching［%］

Y(extension state) = Reflectance measured while maintaining the extension state [%]

Appearance evaluation was performed visually to check for the presence or absence of unevenness, cracks, haze, and breakage.

○: No unevenness, no cracks, no haze, and no breakage

×: No unevenness, no cracks, no haze, and no breakage

××: Cracks, fractures, or unevenness

[Production of a coated phase-shift layer having a double-sided adhesive layer]

(Composition for forming an alignment film)

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

[Tue 28]

(Composition for forming a phase difference layer)

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

(Polymerizable liquid crystal compound A)

[Tue 29]

(Polymerizable liquid crystal compound B)

[Tue 30]

Polymerizable liquid crystal compound A was produced by the method described in Japanese Patent Application Laid-Open No. 2010-31223. In addition, polymerizable liquid crystal compound B was produced by the method described in Japanese Patent Application Laid-Open No. 2009-173893.

(Production of a laminate composed of a substrate, an alignment film, and a layer of a polymerizable liquid crystal compound)

A 50 ㎛ thick cycloolefin resin film [ZF-14-50, manufactured by Zeon Corporation, Japan] was prepared as a substrate, and corona treatment was performed. A composition for forming an alignment film was applied to the surface on which corona treatment was performed using a bar coater. The coating film was dried at 80° C. for 1 minute. The dried coating film was irradiated with polarized UV at an axial angle of 45° using a polarized UV irradiation device [USHIO INC. trade name "SPOT CURE SP-9"], to obtain an alignment film. The polarized UV irradiation was performed so that the accumulated light quantity at a wavelength of 313 nm became 100 mJ/cm2.

Subsequently, a composition for forming a phase difference layer was applied onto the alignment film using a bar coater. The coating film was dried at 120°C for 1 minute. The dried coating film was irradiated with ultraviolet rays using a high-pressure mercury lamp [USHIO INC. product name: “Unicure VB-15201BY-A”].

The ultraviolet irradiation process was carried out under a nitrogen atmosphere so that the accumulated light quantity at a wavelength of 365 nm was 400 mJ/cm2. Immediately after the irradiation, the cured film was placed in an oven set to 5°C for 20 seconds as a cooling process. After taking it out of the oven, the ultraviolet irradiation process and cooling process were immediately carried out again (i.e., the accumulated light quantity of the total of two ultraviolet irradiations was 800 mJ/cm2), thereby obtaining a laminate composed of a substrate, an alignment film, and a layer in which a polymerizable liquid crystal compound was cured.

An adhesive layer, as described later, was laminated on the layer in which the polymerizable liquid crystal compound was cured in the manufactured laminate. Then, the substrate was peeled off from the laminate, and an adhesive layer was similarly laminated on the exposed surface after peeling.

In this way, a coating-type phase-difference layer having a double-sided pressure-sensitive adhesive layer comprising an adhesive layer, a layer in which a polymerizable liquid crystal compound is cured, an alignment film, and an adhesive layer was manufactured. The layer in which the polymerizable liquid crystal compound is cured had a phase-difference value of λ/4.

[Production of a film-type phase-shift layer with a double-sided adhesive layer]

A film called Zeonoa Film (Zeon Corporation, Japan; in-plane retardation value for light with a wavelength of λ = 550 nm: 138 nm), which is a uniaxially stretched film of a cyclic olefin resin, was prepared. The adhesive layers described below were laminated on both sides of this film.

(Adhesive layer)

Acrylic acid butyl: 70 parts by mass, ethyl acrylate: 20 parts by mass, acrylic acid: 2.0 parts by mass, and radical polymerization initiator (2, 2'-azobisisobutyronitrile): 0.2 parts by mass were reacted at 55°C with stirring under a nitrogen atmosphere to obtain an acrylic resin.

Acrylic resin: 100 parts by mass, crosslinking agent ("Coronate L" manufactured by TOSOH CORPORATION): 0.7 parts by mass, silane coupling agent ("X-12-981" manufactured by Shin-Etsu Chemical Co., Ltd.): 0.5 parts by mass were mixed. Ethyl acetate was added so that the total solid concentration became 10%, thereby obtaining an adhesive composition.

The obtained adhesive composition was applied to the release-treated surface of a release-treated polyethylene terephthalate film (thickness: 38 μm) using an applicator so that the thickness after drying became 25 μm. The applied layer was dried at 100°C for 1 minute to obtain a film having an adhesive layer. Thereafter, another release-treated polyethylene terephthalate film (thickness: 38 μm) was bonded onto the adhesive layer. Thereafter, it was cured for 7 days under conditions of a temperature of 23°C and a relative humidity of 50%RH.

＜Example 5＞

In Example 1, a coating-type phase difference layer having the double-sided adhesive layer described above was bonded to the polarizing layer of the laminate composed of the substrate layer/polarizing layer via one of the adhesive layers. The ground axis of the layer in which the polymerizable liquid crystal compound was cured was 45 degrees to the absorption axis of the polarizing layer. In this way, a circular polarizing plate composed of the substrate layer/polarizing layer/adhesive layer/coating-type phase difference plate/adhesive layer was manufactured. A stretching test was performed on the obtained circular polarization. The results are shown in Table 2.

＜Example 6＞

The polarizing layer of the laminate composed of the substrate layer/polarizing layer produced in Example 1 and the film-type retardation layer described above were bonded via an adhesive layer. The ground axis of the film-type retardation layer was 45 degrees to the absorption axis of the polarizing layer. In this way, a circular polarizing plate composed of the substrate layer/polarizing layer/adhesive layer/film-type retardation layer/adhesive layer was produced. A stretching test was performed on the obtained circular polarization. The results are shown in Table 2.

＜Comparative Example 5＞

A circular polarizing plate composed of substrate/polarizing layer/adhesive layer/coating type phase difference layer/adhesive layer was produced in the same manner as in Example 5, except that the laminate composed of substrate layer/polarizing layer produced in Comparative Example 4 was used. A stretching test was performed on the obtained circular polarization. The results are shown in Table 2.

10 layers,
11. Base layer,
12 polarizing layers,

Claims (8)

A stretchable laminate comprising a substrate layer and a polarizing layer,
The moisture content of the above-mentioned layer is 5.0% or less,
The fracture elongation of the above laminate in the absorption axis direction and the transmission axis direction are both 5% to 20%,
A laminate satisfying the following equation (1).
｜E _A －E _T ｜／｜E _A ＋E _T ｜≤0.25 (1)
[In the formula, E _A and E _T represent the tensile elastic moduli in the absorption axis direction and the transmission axis direction, respectively.] In the first paragraph,
A laminate having an overall haze value of 3% or less. In paragraph 1 or 2,
A laminate having a thickness of the polarizing layer of 0.5 ㎛ to 10 ㎛. In paragraph 1 or 2,
The polarizing layer is a laminate composed of a cured product of a polarizing layer forming composition containing a polymerizable liquid crystal compound and a dichroic dye. In paragraph 1 or 2,
A laminate, wherein the content of the dichroic dye in the above polarizing layer is 0.1 to 30 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound. In paragraph 1 or 2,
A laminate further having an adhesive layer on the polarizing layer side. In Article 6,
A laminate having a phase difference layer laminated through the above adhesive layer. A display device, wherein the laminate described in claim 1 or claim 2 is bonded to an image display element.