CN112368143A - Laminated body - Google Patents

Abstract

The invention provides a stretchable laminate which does not change optical characteristics and does not cause appearance defects even when stretched. The stretchable laminate is composed of a base material layer and a polarizing layer, and the base material layer has a moisture content of 5.0% or less and satisfies the following formula (1). I E_A－E_T|/|E_A+E_T| < 0.25(1) [ wherein E is_AAnd E_TAre respectively provided withTensile modulus of elasticity in the directions of the absorption axis and the transmission axis]。

Description

Laminated body

Technical Field

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

Background

Patent document 1 proposes a stretchable display device. Patent document 2 proposes a polarizing plate that can be subjected to thermal bending.

Documents of the prior art

Patent document

Patent document 1: korean laid-open patent No. 10-2016-

Patent document 2: japanese patent No. 5633228

Disclosure of Invention

The purpose of the present invention is to provide a stretchable laminate which does not significantly change optical characteristics such as the visibility correcting monomer transmittance and the visibility correcting polarization degree even when stretched, and which does not cause appearance defects such as haze and cracks.

The present invention provides a laminate as described below.

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

|E_A－E_T|/|E_A+E_T|≦0.25(1)

[ in the formula, E_AAnd E_TThe tensile moduli of elasticity in the directions of the absorption axis and the transmission axis, respectively]

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

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

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

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

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

The laminate according to [6], which comprises a retardation layer laminated via the adhesive layer.

A display device, wherein the laminate according to any one of [1] to [7] is bonded to an image display element.

ADVANTAGEOUS EFFECTS OF INVENTION

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

Drawings

Fig. 1 is a schematic cross-sectional view showing a laminate according to an embodiment of the present invention.

Detailed Description

A laminate according to an embodiment of the present invention (hereinafter simply referred to as "laminate") will be described below with reference to the drawings.

< laminate >

Fig. 1 shows a schematic cross-sectional view of a laminate according to an embodiment of the present invention. The laminate 10 is a stretchable laminate composed of a base layer 11 and a polarizing layer 12. Stretchable means capable of stretching without breaking when the laminate 10 is stretched in at least one of the absorption axis direction and the transmission axis direction. The absorption axis direction is an alignment direction of a dichroic dye and a polymerizable liquid crystal compound, which will be described later, when the polymerizable liquid crystal compound is cured in a state where the dichroic dye and the polymerizable liquid crystal compound constituting the polarizing layer 12 are horizontally aligned with respect to the base material layer surface, or when the dichroic dye exhibiting liquid crystallinity is horizontally aligned with respect to the base material layer surface. The transmission axis direction is a direction which is horizontal to the surface of the base material layer and vertical to the alignment direction when the polymerizable liquid crystal compound is cured in a state where a dichroic dye and a polymerizable liquid crystal compound, which will be described later, constituting the polarizing layer 12 are aligned horizontally with respect to the base material layer surface, or when the dichroic dye exhibiting liquid crystallinity is aligned horizontally with respect to the base material layer surface. The alignment state of the polarizing layer can be confirmed by observation with a polarizing microscope. The laminate sample was inserted between crossed nicols (cross nicols) of a polarization microscope in a direction of about 45 °, and observed in a state where light was leaked. In the case of the vertical orientation, no light leakage occurs in the dark field, and in the case of the horizontal orientation, light leakage occurs in the bright field.

The elongation at break in both the absorption axis direction and the transmission axis direction of the laminate 10 may be 5% or more, for example. When the breaking elongation in both the absorption axis direction and the transmission axis direction is 5% or more, sufficient stretchability tends to be easily obtained. The elongation at break in both the absorption axis direction and the transmission axis direction in the laminate 10 is preferably 5% to 20%, and more preferably 5% to 15%. When the breaking elongation in both the absorption axis direction and the transmission axis direction is 5% to 20%, sufficient stretchability is not easily obtained, and appearance defects such as changes in optical characteristics and 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 break of the laminate when the laminate is stretched in the absorption axis direction or the transmission axis direction in a tensile test, and can be measured according to JIS K7161, for example, using UTM (Universal Testing Machine, autograph AG-X, shimadzu corporation). The elongation at break can be a value at ordinary temperature (temperature 23 ℃ C.).

The tensile elastic modulus of the laminate 10 in the absorption axis direction and the transmission axis direction is E_AAnd E_TIn the case of (2), the following formula (1) is satisfied.

|E_A－E_T|/|E_A+E_T|≦0.25(1)

When the laminate 10 does not satisfy the formula (1), or when the laminate 10 is stretched, the optical characteristics tend to change, the laminate is likely to be broken, or appearance defects such as haze and cracks tend to occur. For this reason, it is estimated that the optical properties of the laminate can be maintained even when the laminate is stretched by providing the laminate with a tensile elastic modulus having a certain degree of isotropy. However, the invention is not limited in any way by this inference. The tensile modulus can be measured by the measurement method described in the section of examples described later. I E_A－E_T|/|E_A+E_TThe lower limit of | may be, for example, 0.01. The tensile modulus may be a value at ordinary temperature (temperature 23 ℃ C.).

The laminate 10 can be produced by combining, for example, the adjustment of the thicknesses of the base layer 11, the polarizing layer 12, and the alignment layer, the selection of a material for the base layer, the selection of a dichroic dye and a polymerizable liquid crystal compound for forming the polarizing layer, the adjustment of the composition ratio thereof, the selection of raw materials used in the composition for forming the alignment layer, the adjustment of the composition ratio, the conditions for forming the polarizing layer and the alignment layer, the adjustment of, for example, coating conditions, drying conditions, polymerization conditions, and the like so as to satisfy formula (1). In particular, since the tensile elastic modulus of the laminate and the tensile elastic modulus of the base material layer have a relationship, it is preferable to use a base material layer having an elongation of 5% or more.

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

|E_A－E_T|/|E_A+E_T|≤0.20 (2)

Modulus of elasticity in tension E_AAnd E_TFor example, the pressure is 1MPa to 30000MPa, preferably 10MPa to 20000MPa, more preferably 50MPa to 15000MPa, and may be 1000MPa to 7000MPa, or may be 1000MPa to 5000 MPa. Modulus of elasticity in tension E_AAnd E_TIn all cases of 50MPa to 15000MPa, the laminate 10 tends not to be easily broken even when stretched.

The total haze value of the laminate 10 may be 3% or less, for example. When the total haze value is 3% or less, it can be suitably used for a display device. The total haze value of the laminate 10 is preferably 2.8% or less, and more preferably 2.5% or less. When the total haze value is 3% or less, or when the laminate 10 is used in a display device, the visibility tends to be improved easily. The total haze value can be measured according to the method described in the section of examples described later. On the other hand, the total haze value is usually 0.1% or more. The total haze value can be measured based on the measurement method described in the section of example described later.

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

The polarization performance of the laminate 10 can be measured using a spectrophotometer. For example, the transmittance (T1) in the transmission axis direction (direction perpendicular to the orientation direction of the dichroic dye) and the transmittance (T2) in the absorption axis direction (same direction as the orientation direction of the dichroic dye) in the range of a visible light wavelength of 380nm to 780nm were measured by a two-beam method using a device in which a support with a polarizing plate was attached to a spectrophotometer. The polarization performance in the visible light range can be calculated by calculating the single transmittance and the degree of polarization for each wavelength using the following formulas (3) and (4), and further performing visibility correction using a 2-degree field of view (C light source) according to JIS Z8701, thereby calculating the visibility correction single transmittance (Ty) and the visibility correction degree of polarization (Py).

Monomer transmittance (%) - (T1+ T2)/2 formula (3)

Degree of polarization (%) - (T1-T2)/(T1 + T2) × 100 formula (4)

The visibility-correcting monomer transmittance of the laminate 10 may be, for example, 30% or more, preferably 35% or more, and more preferably 38% or more. On the other hand, the visibility-correcting monomer transmittance of the laminate 10 is generally 70% or less, preferably 48% or less, and more preferably 46% or less. The visibility correcting monomer transmittance can be measured based on the method described in the column of the example described later.

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

The visibility correction polarization degree of the laminate 10 may be, for example, 80% or more, preferably 85% or more, and more preferably 90% or more. On the other hand, the visibility correction polarization degree of the laminate 10 is usually 100% or less, and may be 99.99% or less, or may be 99.0% or less. The visibility correction polarization degree can be measured by the method described in the section of the example below.

The difference (Δ P) between the visibility correction polarization degrees before and after stretching in the absorption axis direction and the transmission axis direction of the laminate 10 is, for example, 3% or less, preferably 2.5% or less, and more preferably 2% or less. In a preferred embodiment, the difference (Δ P) between the visibility correction polarization degrees before stretching and after stretching by 5% in the absorption axis direction and the transmission axis direction of the laminate 10 is, for example, 3% or less, preferably 2.5% or less, and more preferably 2% or less. In a more preferred embodiment, the difference (Δ P) between the visibility correction polarization degrees before stretching and after stretching by 10% in the absorption axis direction and the transmission axis direction of the laminate 10 is, for example, 3% or less, preferably 2.5% or less, and more preferably 2% or less.

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

The layers constituting the laminate 10 will be described below.

[ base Material layer ]

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

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

Examples of typical commercially available products of cycloolefin resins include "Topas" (registered trademark) (manufactured by Ticona), "Arton" (registered trademark) (manufactured by JSR corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by Zeon corporation), and "APEL" (registered trademark) (manufactured by mitsui chemical co., ltd). The cycloolefin resin can be formed into a resin film by a known method such as a solvent casting method or a melt extrusion method. A commercially available cycloolefin resin film may be used. Typical examples of commercially available products of the cycloolefin resin film include "escina" (registered trademark), "SCA 40" (registered trademark) (available from waterlogging chemical co., ltd.), "ZeonorFilm" (registered trademark) (available from Optes corporation), and "Arton film" (registered trademark) (available from JSR corporation).

Examples of commercially available products represented by a resin film made of cellulose ester include "Fuji-tacfim" (manufactured by Fuji photo film corporation); "KC 8UX 2M", "KC 8 UY" and "KC 4 UY" (manufactured by Konika Mingta Co., Ltd.).

The moisture percentage of the base material layer 11 is 5.0% or less, preferably 3.0% or less. The moisture percentage of the base material layer 11 may be 0.0% or more. When the moisture content of the base layer 11 is 5.0% or less, uniformity of the alignment directions of the polymerizable liquid crystal compound and the dichroic dye tends to be improved when the polarizing layer 12 is formed. In particular, when the laminate 10 is stretched, unevenness in optical characteristics is likely to be observed, and as a result, even after stretching, good optical characteristics of the polarizing layer are likely to be maintained. The moisture content of the base material layer was measured by the method described in the examples described below.

From the viewpoint of making the laminate 10 thinner, the resin film is preferably thin, and when too thin, it tends to be difficult to ensure impact resistance. The thickness of the resin film may be, for example, 10 to 200. mu.m, preferably 15 to 150. mu.m, and more preferably 20 to 100. mu.m.

The base material layer 11 may have a hard coat layer, an antireflection layer, or an antistatic layer on at least one surface. The base layer 11 may be formed with a hard coat layer, an antireflection layer, an antistatic layer, or the like only on the surface on the side where the polarizing layer 12 is not formed. The base layer 11 may have a hard coat layer, an antireflection layer, an antistatic layer, or the like formed only on the surface on the side where the polarizing layer 12 is formed. As the base layer 11, a window film described later may be used.

[ polarizing layer ]

The polarizing layer 12 is preferably a layer composed of a cured product of a composition containing 1 or more kinds of polymerizable liquid crystal compounds [ hereinafter also referred to as polymerizable liquid crystal (a) ] and dichroic pigments or a layer composed of a cured product of a composition containing 1 or more kinds of dichroic pigments exhibiting liquid crystallinity. When the polarizing layer 12 has polarization characteristics in the plane direction of the laminate 10, the dichroic dye and the polymerizable liquid crystal (a) may be cured in the state of being horizontally aligned with respect to the plane of the laminate 10, or the polymerizable liquid crystal (a) may be horizontally aligned with respect to the dichroic dye exhibiting liquid crystallinity in the plane of the laminate 10, and when the polarizing layer 12 has polarization characteristics in the thickness direction of the laminate 10, the dichroic dye and the polymerizable liquid crystal (a) may be cured in the normal state of being vertically aligned with respect to the plane of the laminate 10, or the polymerizable liquid crystal (a) may be vertically aligned with respect to the dichroic dye exhibiting liquid crystallinity in the plane of the laminate 10. The polarizing layer 12 is preferably a coating layer, and may be a cured product of a composition for forming a polarizing layer [ hereinafter, also referred to as composition (a) ] containing 1 or more kinds of polymerizable liquid crystal (a) and a dichroic dye.

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

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

(polymerizable liquid Crystal)

The polymerizable liquid crystal (a) is a compound having a polymerizable group and liquid crystallinity. The polymerizable group is a group participating in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group capable of participating in a polymerization reaction by an active radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chloroethenyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxetanyl group, and an oxetanyl group. Among them, preferred are acryloyloxy, methacryloyloxy, vinyloxy, oxetanyl and oxetanyl, and more preferred is acryloyloxy. The liquid crystallinity may be a thermotropic liquid crystal or a lyotropic liquid crystal, and when mixed with a dichroic dye as described later, a thermotropic liquid crystal is preferable.

When the polymerizable liquid crystal (a) is a thermotropic liquid crystal, the polymerizable liquid crystal (a) may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a smectic liquid crystal compound. When the polymerizable reaction is used to function as a polarizing film, 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 them, more preferred are smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase and smectic I phaseThe higher order smectic liquid crystal compound of phase, smectic J phase, smectic K phase or smectic L phase is more preferably a higher order smectic liquid crystal compound forming smectic B phase, smectic F phase or smectic I phase. When the liquid crystal phase formed by the polymerizable liquid crystal (a) is such a high order smectic phase, a polarizing layer having higher polarizing performance can be produced. In addition, the polarizing layer having such a high polarizing performance obtains bragg peaks from a high-order structure such as a hexagonal phase or a crystal phase in the X-ray diffraction measurement. The Bragg peak is a peak derived from a molecular-oriented periodic structure, and can be obtained at a periodic interval of

The film of (1). From the viewpoint of obtaining higher polarization characteristics, the polarizing layer of the present invention preferably contains a polymer of the polymerizable liquid crystal (a) polymerized in a smectic phase of the polymerizable liquid crystal (a).

Specific examples of such a compound include a compound [ hereinafter also referred to as compound (I) ] represented by the following formula (I). The polymerizable liquid crystal (a) may be used alone or in combination of 2 or more.

U¹－V¹－W¹－X¹－Y¹－X²－Y²－X³－W²－V²－U²(I)

[ in the formula (A), X¹、X²And X³Each independently represents a 2-valent aromatic group or a 2-valent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the aromatic group having a valence of 2 or the alicyclic hydrocarbon group having a valence of 2 may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group. The carbon atom constituting the aromatic group having a valence of 2 or the alicyclic hydrocarbon group having a valence of 2 may be substituted with an oxygen atom, a sulfur atom or a nitrogen atom. Wherein, X¹、X²And X³At least one of them is a 1, 4-phenylene group which may have a substituent or a cyclohexane-1, 4-diyl group which may have a substituent.

Y¹、Y²、W¹And W²Independently of one another, are a single bond or a divalent linking group.

V¹And V²Independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent. -CH constituting the alkanediyl group₂-may be substituted by-O-, -S-or-NH-.

U¹And U²Independently of each other, a polymerizable group or a hydrogen atom, at least one of which is a polymerizable group.]

In the compound (I), X¹、X²And X³At least one of them is a 1, 4-phenylene group which may have a substituent, or a cyclohexane-1, 4-diyl group which may have a substituent. In particular X¹And X³Preferred is cyclohexane-1, 4-diyl which may have a substituent, and the cyclohexane-1, 4-diyl is further preferably trans-cyclohexane-1, 4-diyl. When the compound (I) contains cis-cyclohexane-1, 4-diyl, smectic liquid crystallinity tends to be easily exhibited. Examples of the substituent optionally having a 1, 4-phenylene group which may have a substituent or a cyclohexane-1, 4-diyl group which may have a substituent include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, and a butyl group, and a halogen atom such as a cyano group, a chlorine atom, and a fluorine atom. The 1, 4-phenylene or cyclohexane-1, 4-diyl radical is preferably unsubstituted.

Y¹And Y²Are each, independently of one another, preferably a single bond, -CH₂CH₂－、－CH₂O－、－ COO－、－OCO－、－N＝N－、－CR^a＝CR^b-, -C.ident.C-or-CR^a＝N －，R^aAnd R^bEach independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y is¹And Y²More preferably-CH₂CH₂-, -COO-, -OCO-or a single bond, more preferably X¹、X²And X³Case where all do not include cyclohexane-1, 4-diyl, Y¹And Y²Are different bonding modes from each other. Y is¹And Y²When the bonding systems are different from each other, smectic liquid crystallinity is likely to be exhibitedThe trend of (c).

W¹And W²Preferably a single bond, -O-, -S-, -COO-or OCO-independently of one another, and more preferably a single bond or-O-independently of one another.

As V¹And V²Examples of the alkanediyl group having 1 to 20 carbon atoms include a methylene group, an ethylene group, a propane-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 tetradecyl-1, 14-diyl group, and an eicosyl-1, 20-diyl group. V¹And V²Preferably a C2-12 alkanediyl group, and more preferably a linear C6-12 alkanediyl group. The crystallinity is improved by the linear alkanediyl group having 6 to 12 carbon atoms, and smectic liquid crystallinity tends to be easily exhibited.

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

U¹And U²All of them are preferably polymerizable groups, and all of them are more preferably photopolymerizable groups. The polymerizable liquid crystal compound having a photopolymerizable group is more polymerizable at a lower temperature than the polymerizable liquid crystal compound having a thermopolymerizing group, and therefore, is advantageous in that a polymer can be formed in a state where the liquid crystal is more highly ordered.

U¹And U²The polymerizable groups represented by the formulae 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-chloroethenyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxetanyl group, and an oxetanyl group. Among them, preferred are acryloyloxy, methacryloyloxy, vinyloxy, oxetanyl and oxetanyl, and more preferred is methacryloyloxy or acryloyloxy.

Examples of such a polymerizable liquid crystal compound include the following.

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

(dichroic dye)

The dichroic dye is a dye having a property that the absorbance of molecules in the major axis direction and the absorbance of molecules in the minor axis direction are different from each other. The dichroic dye preferably has a property of absorbing visible light, and more preferably has an absorption maximum wavelength (λ MAX) in a range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes,

Oxazine pigments, cyanine pigments, naphthalene pigments, azo pigments, anthraquinone pigments, and the like. Among these, the dichroic dye is preferably an azo dye. Examples of the azo dye include monoazo dyes, disazo dyes, trisazo dyes, tetraazo dyes, and stilbene azo dyes, and disazo dyes and trisazo dyes are preferable. The dichroic dyes may be used alone or in combination. In order to obtain absorption in the entire visible light region, it is preferable to use 3 or more kinds of dichroic dyes in combination, and it is more preferable to use 3 or more kinds of azo dyes in combination.

Examples of the azo dye include a compound represented by formula (II) (hereinafter, also referred to as "compound (II)").

T¹－A¹(－N＝N－A²)_p－N＝N－A³－T²(II)

[ in the formula (II),

A¹and A²And A³Independently of each other, represents a 1, 4-phenylene group which may have a substituent, a naphthalene-1, 4-diyl group or a 2-valent heterocyclic group which may have a substituent. T is¹And T²Is an electron withdrawing group or an electron donating group, and is present at a position of substantially 180 DEG in relation to the azo bond plane. p represents an integer of 0 to 4. When p is 2 or more, each A²May be the same or different. In the range where the visible region shows absorption, -N-may be substituted by-C-, -COO-, -NHCO-or-N-CH-bonds.]

As A¹、A²And A³The substituent optionally contained in the 1, 4-phenylene group, the naphthalene-1, 4-diyl group and the 2-valent heterocyclic group in (A) is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group and a butyl group; alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy and butoxy groups; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; halogen atoms such as chlorine atom and fluorine atom; a substituted or unsubstituted amino group such as an amino group, a diethylamino group or a pyrrolidinyl group (the substituted amino group means an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms or an amino group in which 2 substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms; the unsubstituted amino group is-NH₂. ). Examples of the alkyl group 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 a vinyl group, a propane-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, and an octane-1, 8-diyl group. For inclusion in a high order liquid crystal structure such as smectic liquid crystal, A¹、 A²And A³Preference is given to 1, 4-phenylene which is unsubstituted or substituted by methyl or methoxy on hydrogen, or 2-valent heterocyclic radicals, p preferably being 0 or 1. Among them, from the viewpoint of having both the simplicity of molecular synthesis and high performance, p is more preferably 1, and A is more preferably¹、A²And A³At least 2 of the 3 structures of (a) are 1, 4-phenylene.

Examples of the heterocyclic group having a valence of 2 include those derived from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, and,

Azole and benzo

A group obtained by removing 2 hydrogen atoms from an azole. A. the²When the heterocyclic group has a valence of 2, the heterocyclic group preferably has a structure having a molecular bond angle of substantially 180 °, more preferably a structure in which two 5-membered rings are fused, such as benzothiazole, benzimidazole, and benzimidazole

An azole structure.

T¹And T²Is an electron-withdrawing group or an electron-donating group, preferably has a mutually different structure, and more preferably T¹Is an electron withdrawing group, T²Is a combination of electron donating groups, or T¹Is an electron donating group, T²Is a combination of electron withdrawing groups. Specifically, T¹And T²Independently of each other, it is preferably an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group in which 2 substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, or a trifluoromethyl group. In order to be included in a high-order liquid crystal structure such as smectic liquid crystal, a structure having a smaller molecular exclusion volume is required, and therefore T is¹And T²Independently of each other, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, an amino group having 1 or 2 alkyl groups having 1 to 6 carbon atoms, or an amino group in which 2 substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms is preferable.

Examples of such azo dyes include the following compounds.

In the formulae (2-1) to (2-6), B¹～B²⁰Independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the substituted amino group and the unsubstituted amino group are as defined above), a chlorine atom or a trifluoromethyl group. From the viewpoint of obtaining high polarization performance, B²、B⁶、B⁹、B¹⁴、B¹⁸、B¹⁹Preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

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

When n1 is 2 or more, a plurality of B²These may be the same or different, and when n2 is 2 or more, a plurality of B' s⁶These may be the same or different, and when n3 is 2 or more, a plurality of B' s⁹These may be the same or different, and when n4 is 2 or more, a plurality of B' s¹⁴May be the same or different.

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

[ formula (2-7) wherein R¹～R⁸Independently of each other, a hydrogen atom, -R^x、－NH₂、－ NHR^x、－NR^x ₂、－SR^xOr a halogen atom.

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

As described above

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

[ formula (2-8) wherein R⁹～R¹⁵Independently of each other, a hydrogen atom, -R^x、－NH₂、－ NHR^x、－NR^x ₂、－SR^xOr a halogen atom.

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

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

[ formula (2-9) wherein R¹⁶～R²³Independently of each other, a hydrogen atom, -R^x、－NH₂、－NHR^x、－NR^x ₂、－SR^xOr a halogen atom.

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

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

The cyanine dye is preferably a compound represented by the formula (2-10) or a compound represented by the formula (2-11).

[ in the formula (2-10), D¹And D²Independently of each other, represents a group represented by any one of the formulae (2-10 a) to (2-10 d).

n5 represents an integer of 1 to 3. ]

[ formula (2-11) wherein D³And D⁴Independently of each other, represents a group represented by any one of the formulae (2-11 a) to (2-11 h).

n6 represents an integer of 1 to 3. ]

From the viewpoint of obtaining good light absorption characteristics, the content of the dichroic dye (the total amount thereof in the case of including a plurality of types) is 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). When the content of the dichroic dye is less than this range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained, and when it exceeds this range, the alignment of the liquid crystal molecules may be inhibited.

(alignment layer)

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

The alignment layer easily aligns the liquid crystal of the polymerizable liquid crystal. The state of liquid crystal alignment such as horizontal alignment, vertical alignment, hybrid alignment, and tilt alignment varies depending on the properties of the alignment layer and the polymerizable liquid crystal, and the combination thereof is arbitrarily selected. For example, if the alignment layer is a material exhibiting horizontal alignment as an alignment regulating force, the polymerizable liquid crystal can be formed into horizontal alignment or hybrid alignment, and if the alignment layer is a material exhibiting vertical alignment, the polymerizable liquid crystal can be formed into vertical alignment or tilt alignment. The expressions horizontal and vertical indicate the direction of the long axis of the aligned polymerizable liquid crystal with the plane of the polarizing layer 12 as a reference. For example, vertical alignment refers to having the long axis of the polymerizable liquid crystal aligned in a direction perpendicular to the plane of the polarizing layer 12. Perpendicular here means 90 ° ± 20 ° with respect to the plane of the polarizing layer 12.

The alignment regulating force can be arbitrarily adjusted depending on the surface state and the rubbing condition when the alignment layer is formed of an alignment polymer, and can be arbitrarily adjusted depending on the polarization irradiation condition when the alignment layer is formed of a photo-alignment polymer. Further, the liquid crystal alignment can be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

The alignment layer formed between the base layer 11 and the polarizing layer 12 is preferably insoluble in a solvent used when the polarizing layer 12 is formed on the alignment layer, and has heat resistance for removal of the solvent and heat treatment for alignment of the liquid crystal. The alignment layer may be an alignment layer made of an alignment polymer, a photo-alignment layer, a groove (grove) alignment layer, or the like. Among these, when used for a long roll resin film, the photo-alignment layer is preferable from the viewpoint of easily controlling the alignment direction.

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

Examples of the orientation polymer used for the orientation layer made of the orientation polymer include polyamides having amide bonds in the molecule, gelatins, polyimides having imide bonds in the molecule, and polyamic acids, polyvinyl alcohols, alkyl-modified polyvinyl alcohols, polyacrylamides, and polyacylamides, which are hydrolysates thereof

Oxazoles, polyethyleneimines, polystyrenes, polyvinylpyrrolidones, polyacrylic acids, polyacrylates, and the like. Among these, polyvinyl alcohol is preferable as the orientation polymer. These alignment polymers may be used alone, or 2 or more kinds may be used in combination.

When an alignment layer composed of an alignment polymer is formed on a base layer composed of a resin film, the alignment layer composed of an alignment polymer is generally obtained by applying a composition in which an alignment polymer is dissolved in a solvent (hereinafter, also referred to as "alignment polymer composition") to a resin film and removing the solvent, or applying an alignment polymer composition to a resin film and removing the solvent and rubbing (rubbing method).

Examples of the solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene; and the like. These solvents may be used alone, or 2 or more of them may be used in combination.

The concentration of the oriented polymer in the oriented polymer composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, in terms of solid content, relative to the solution, as long as the oriented polymer is completely soluble in the solvent.

As the alignment polymer composition, a commercially available alignment layer forming material can be used as it is. Examples of commercially available materials for forming an alignment layer include sunover (registered trademark) (manufactured by nippon chemical industry co., ltd.) and Optomer (registered trademark) (manufactured by JSR corporation).

Examples of the method for applying the oriented polymer composition to the resin film include known methods such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a coating method such as a bar coating method and a coater method, and a printing method such as a flexographic printing method. When the laminate of the present invention is produced by a Roll-to-Roll type continuous production method, a printing method such as a gravure coating method, a die coating method, or a flexographic printing method is generally used as the coating method.

The solvent contained in the oriented polymer composition is removed to form a dried coating film of the oriented polymer. Examples of the method for removing the solvent include a natural drying method, a forced air drying method, a heat drying method, and a reduced pressure drying method.

As a rubbing method, a method of bringing a film of an oriented polymer into contact with a rubbing roll is exemplified. The rubbing roll is a roll wound with a rubbing cloth and capable of rotating.

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

The photoreactive group refers to a group that generates liquid crystal aligning ability by irradiation with light. Specifically, a photoreaction, which is a source of the liquid crystal alignment ability, such as an alignment induction or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction of molecules by irradiation with light, occurs. Among these photoreactive groups, a dimerization reaction or a photocrosslinking reaction is preferably caused in view of excellent orientation. The photoreactive group capable of causing the above reaction preferably has an unsaturated bond, particularly a double bond, and more preferably has at least one selected from a carbon-carbon double bond (C ═ C bond), a carbon-nitrogen double bond (C ═ N bond), a nitrogen-nitrogen double bond (N ═ N bond), and a carbon-oxygen double bond (C ═ O bond).

Examples of the photoreactive group having a C ═ C bond include a vinyl group, a polyene group, a stilbene group, a styrylpyridinyl group, a chalcone group, and a cinnamoyl group. From the viewpoint of easy control of reactivity and the orientation restriction when photo-orientation is exhibited, chalcone group and cinnamoyl group are preferable. Examples of the photoreactive group having a C ═ N bond include groups having structures such as aromatic schiff bases and aromatic hydrazones. Examples of the photoreactive group having an N ═ N bond include groups having a basic structure of azoxybenzene such as an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a bisazo group, and a formazan group. Examples of the photoreactive group having a C ═ O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and haloalkyl groups. Among them, a photoreactive group capable of undergoing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group are preferable because a photo-alignment layer which requires a relatively small amount of polarized light irradiation and is excellent in thermal stability and stability with time can be easily obtained. As the polymer having a photoreactive group, a polymer having cinnamoyl groups, in which the terminal portion of the side chain of the polymer is a cinnamic acid structure, is particularly preferable.

From the viewpoint of ease of handling for obtaining the composition for forming a photo-alignment layer and an alignment layer capable of realizing high-durability alignment, a polymer having a photoreactive group is particularly preferable, and for example, a polymer having a group represented by the formula (a ') in a side chain (hereinafter, also referred to as "polymer (a')", depending on the case) is used.

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

X¹Represents a single bond, -O-, -COO-, -OCO-, -N-, -CH-CH

-or-CH₂－。

Y¹Represents a single bond or-O-.

R¹And R²Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

The bonding sites corresponding to the polymer backbone. ]

In the formula (A'), X¹Is a single bond, -O-, -COO-, -OCO-, -N-, -C-and-CH₂Any of the above-mentioned (a ') is particularly preferable because the production of the polymer (a') itself becomes easy.

In the formula (A'), R¹And R²Each independently represents a hydrogen atom, a halogen atom, a haloalkyl group, a haloalkoxy group, a cyano group, a nitro group, an alkyl group, an alkoxy group, an aryl group, an allyloxy group, an alkoxycarbonyl group, a carboxyl group, a sulfonic group, an amino group or a hydroxyl group, and the carboxyl group and the sulfonic group may form a salt with an alkali metal ion. Of these, R is more preferable¹And R²Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, and a butyl group, and examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group.

The main chain of the polymer (A') is not particularly limited, but it is preferable that the polymer (A) has a (meth) acrylate unit represented by the formula (M-1) or the formula (M-2); a (meth) acrylamide unit represented by the formula (M-3) or the formula (M-4); a vinyl ether unit represented by the formula (M-5) or the formula (M-6); a main chain polymer (A) comprising a (meth) styrene unit represented by the formula (M-7) or (M-8) and a vinyl ester unit represented by the formula (M-9) or (M-10), wherein the polymer (A') preferably has a main chain comprising a unit selected from the group consisting of a (meth) acrylate unit and a (meth) acrylamide unit. The "main chain of the polymer (A ') referred to herein means the longest molecular chain among the molecular chains of the polymer (A').

The unit represented by any one of the formulae (M-1) to (M-10) and the group represented by the formula (A') may be bonded directly or through 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 2-valent aliphatic hydrocarbon group which may have a substituent, a 2-valent aromatic hydrocarbon group which may have a substituent, and a 2-valent group obtained by combining these groups. Specific examples of the optionally substituted 2-valent aromatic hydrocarbon group include phenylene, 2-methoxy-1, 4-phenylene, 3-methoxy-1, 4-phenylene, 2-ethoxy-1, 4-phenylene, 3-ethoxy-1, 4-phenylene, 2,3, 5-trimethoxy-1, 4-phenylene, and the like. Among these, the linking group is preferably an aliphatic hydrocarbon group, and more preferably an alkanediyl group having 1 to 11 carbon atoms which may have a substituent. The alkanediyl group may be 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, an undecamethylene group, or the like, and these may be linear or branched. The alkanediyl group may have a substituent. The substituent is, for example, an alkoxy group having 1 to 4 carbon atoms.

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

[ in the formula (A), X¹、Y¹、R¹、R²And n has the same meaning as formula (A'),

S¹is an alkanediyl group having 1 to 11 carbon atoms,

the structure represented by any one of the formulae (M-1) to (M-10). ]

The molecular weight of the polymer (A') or the polymer (A) is preferably 1X 10 in terms of the weight average molecular weight in terms of polystyrene determined by a gel permeation method (GPC method)³～1×10⁷The range of (1). However, when the molecular weight is high, the solubility in a solvent is lowered, and the preparation of the composition for forming an alignment layer is difficult, and there are cases where light is appliedSince the sensitivity of irradiation tends to be low, it is preferably 1 × 10⁴～ 1×10⁶The range of (1).

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

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

S²Represents an alkanediyl group having 1 to 11 carbon atoms.

The structure represented by any one of the formulae (M-1) to (M-10).

X²Represents a single bond, -O-, -COO-, -OCO-, -N-, -CH-CH

-or-CH₂－。

Y²Represents a single bond or-O-.

R³And R⁴Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.]

In the formula (B), S²Specific examples of (A) and S of formula (A)¹In the same manner as in the specific example, R³And R⁴Specific examples of the alkyl group and the alkoxy group in (A) are respectively the same as R in the formula (A)¹And R²The same applies to specific examples.

When the mole fractions of the structural unit (A) and the structural unit (B) with respect to the total structural units of the polymer (A) are p and q, respectively, (p + q is 1.), the relationship of 0.25 < p.ltoreq.1 and 0. ltoreq.q.ltoreq.0.75 is preferably satisfied [ here, the case where the polymer (A) has the structural unit (A), and p is 1 means that the polymer (A) is a polymer composed of the structural unit (A). In the polymer comprising the structural unit (A), the number of the structural unit (A) may be 1 or 2 or more. The polymer (a) may have a structural unit other than the structural unit (a) and the structural unit (B) (hereinafter, may be referred to as "other structural unit" in some cases) as long as the orientation ability by light irradiation is not significantly impaired.

The polymer (a) can be produced by polymerizing or copolymerizing a monomer derived from the structural unit (a) and, if necessary, a monomer derived from the structural unit (B) and another structural unit. In the polymerization or copolymerization, an addition polymerization method is generally used. Examples of the addition polymerization include chain polymerization such as radical polymerization, anionic polymerization and cationic polymerization, and coordination polymerization. The polymerization conditions are set so as to satisfy the above-mentioned preferable molecular weight of the polymer (a) depending on the kind of the monomer used and the amount thereof.

As described above, the polymer (a) is described in detail as a preferable example of the polymer having a photoreactive group, but 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. The solvent can dissolve the polymer having the photoreactive group, and can be appropriately selected within a range that a composition for forming an alignment layer having an appropriate viscosity can be obtained. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone or propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform-chlorobenzene; amide solvents such as N-methylpyrrolidone, N-dimethylformamide, γ -butyrolactone and dimethylacetamide. These solvents may be used alone in 1 kind, or may be used in combination of plural kinds.

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

The method of applying the composition for forming a photo-alignment layer to a resin film includes the same method as the method of applying the above-described alignment polymer composition to a resin film. Examples of the method for removing the solvent from the applied composition for forming a photo-alignment layer include the same methods as the method for removing the solvent from the alignment polymer composition.

The polarized light may be irradiated directly by removing the solvent from the composition for forming a photo-alignment layer applied on a resin film or the like, or by irradiating polarized light from the resin film side and transmitting the polarized light. In addition, the polarized light is preferably substantially parallel light. The wavelength of the irradiated polarized light is preferably a wavelength region in which the photoreactive group of the polymer or monomer having the photoreactive group can absorb light energy. Specifically, UV (ultraviolet) light having a wavelength of 250 to 400nm is particularly preferable. Examples of the light source used for the polarized light irradiation include a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, and ultraviolet laser such as KrF and ArF, and more preferably a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp. These lamps are preferable because the emission intensity of ultraviolet rays having a wavelength of 313nm is large. The light from the light source is irradiated through an appropriate polarizing plate, and polarized light can be irradiated. As the polarizing plate, a polarizing filter, a polarizing prism such as a glan-thompson prism or a glan-taylor prism, or a wire grid polarizer can be used.

Note that, if masking is performed during rubbing or polarized light irradiation, a plurality of regions (patterns) in which the liquid crystal is aligned in different directions can be formed.

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

Examples of the method for obtaining the groove alignment layer include a method in which the groove alignment layer is formed by exposing through an exposure mask having a slit with a pattern shape on the surface of a photosensitive polyimide film, and then performing development and rinsing, and a method in which a layer of a UV curable resin before curing is formed on a plate-like master having a groove on the surface, and the resin layer is cured after being transferred to a resin film; and a method in which a roll-shaped master having a plurality of grooves is pressed against a film of a UV curable resin before curing, which is formed on a resin film, to form irregularities, and then curing is performed. Specifically, there are 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 less orientation disorder, the width of the convex portion of the groove orientation layer is preferably 0.05 to 5 μm, the width of the concave portion is preferably 0.1 to 5 μm, and the depth of the step of the unevenness is preferably 2 to 1 μm.

(other layer)

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

The laminate 10 may have a phase difference layer. Examples of the retardation layer include a λ/4 plate, a λ/2 plate, a normal C plate, a λ/4 plate having reverse wavelength dispersibility, a λ/2 plate having reverse wavelength dispersibility, and combinations thereof. Examples of the combination of the retardation layer include a combination of a λ/4 plate and a positive C plate having reverse wavelength dispersibility, and a combination of a λ/2 plate and a λ/4 plate. The retardation layer may be made of a transparent resin film forming the substrate layer or a composition containing a polymerizable liquid crystal compound. The retardation layer can be produced by applying a composition containing a polymerizable liquid crystal compound to an alignment film and curing the polymerizable liquid crystal compound. The retardation 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 substrate. For forming the retardation layer, for example, the polymerizable liquid crystal compounds exemplified in the above description of the polarizing layer 12, the polymerizable liquid crystal compounds described in jp 2010-31223 a and jp 2009-173893 a, and the like can be used. The alignment film included in the retardation layer may be, for example, the alignment film exemplified in the description of the polarizing layer 12 described above. The base material included in the retardation layer may be, for example, a resin film exemplified in the description of the base material layer 11. The retardation layer may be laminated via the above-described adhesive layer.

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

The laminate 10 may have a window film and a light-shielding pattern (outer frame) disposed on the viewing side of the polarizing layer 12. The window film is formed by including a hard coating layer on at least one surface of a transparent base material layer. Window films do not have the characteristics of being as rigid as existing glass, but rather flexible. The light-shielding pattern can be used to hide the wiring of the display device from the user. The laminate 10 may be laminated on the touch sensor.

< method for producing laminate >

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

(polymerization initiator)

The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal or the like. As the polymerization initiator, a photopolymerization initiator which generates active radicals by the action of light is preferable from the viewpoint of not depending on the phase state of the thermotropic liquid crystal.

Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, and,Alkyl phenone compound, acylphosphine oxide compound, triazine compound, iodine

Onium salts and sulfonium salts, and the like.

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

Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4 ' -methyldiphenyl sulfide, 3 ', 4,4 ' -tetrakis (t-butylperoxycarbonyl) benzophenone, and 2,4, 6-trimethylbenzophenone.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1, 2-diphenyl-2, 2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1- [ 4- (2-hydroxyethoxy) phenyl ] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and oligomers of 2-hydroxy-2-methyl-1- [ 4- (1-methylvinyl) phenyl ] propan-1-one.

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

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

As the polymerization initiator, a commercially available initiator can be used. Examples of commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, OXE03 (product of Ciba Specialty Chemicals); SEIKUOL (registered trademark) BZ, Z and BEE (manufactured by seiko chemical corporation); kayacure (registered trademark) BP100 and UVI-6992 (manufactured by Dow Chemical Co., Ltd.); adeka Optomer SP-152, N-1717, N-1919, SP-170, Adeka Arkls NCI-831, Adeka Arkls NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A and TAZ-PP (manufactured by Japan Sibel Hegner Co., Ltd.); and TAZ-104 (manufactured by Kabushiki Kaisha and Chemicals); and the like. The composition (a) may contain 1 polymerization initiator, or may contain two or more polymerization initiators depending on the light source.

The content of the polymerization initiator in the composition (a) may be appropriately adjusted depending on the kind of the polymerizable liquid crystal and the amount thereof. 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, based on 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.

(sensitizer)

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

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

(polymerization inhibitor)

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

Examples of the polymerization inhibitor include radical scavengers such as hydroquinone, alkoxy-containing catechol (e.g., butylcatechol), pyrogallol, and 2,2,6, 6-tetramethyl-1-piperidinyloxy radical; thiophenols; beta-naphthylamines and beta-naphthols, and the like.

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 still more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal. When the content of the polymerization inhibitor is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal.

(leveling agent)

The composition (A) may contain a leveling agent. The leveling agent is an additive having a function of adjusting the fluidity of the composition and flattening a film obtained by coating the composition. Examples of the leveling agent include organically modified silicone oil-based leveling agents, polyacrylate-based leveling agents, and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all of those produced by Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all of those produced by shin-Etsu chemical industries Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of those produced by Momentive practical Materials Japan Co., Ltd.), fluorinert (registered trademark) FC-72, fluorinert-40, fluorinert-43, fluorinert-3272, fluorinert-40, GAFC 43, fluorinert-3243, fluorinert-32, GAFC (all of those produced by Momentive industries, GAFC 3, FAC-4790, FAC-C-3, FACC 443, GAF-102, GAFC, FAC-443, FAC-3-70, FAC-Mitsu K, TSF-F-4445, TSF-4446, TSF 482, TSF-mason the name of the trade name of the trade mark of the chemical industries of the trade company of the company, GAFC, MEF-mason the company of the trade name of the company of the trade mark, F-Top (trade name) EF301, Ftop EF303, Ftop EF351, Ftop EF352 (all manufactured by Mitsubishi materials Kabushiki Kaisha), Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40, SA-100 (all manufactured by SEAGC chemical Co., Ltd.), trade name E1830, trade name E5844 (chemical research DAIKIN FINE Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all manufactured by BM Chemie Co., Ltd.), and the like. Among them, 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 still more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal. When the content of the leveling agent is within the above range, the polymerizable liquid crystal is easily horizontally aligned, and the obtained polarizing layer tends to be smoother. When the content of the leveling agent relative to the polymerizable liquid crystal exceeds the above range, the obtained polarizing layer tends to be uneven. The composition (a) may contain 2 or more leveling agents.

(solvent)

The composition (a) may contain a solvent. In general, since the polymerizable liquid crystal compound has a high viscosity, it is easy to apply the composition by forming the composition (a) dissolved in a solvent, and as a result, the formation of the polarizing layer is often facilitated. The solvent is preferably a solvent that can completely dissolve the polymerizable liquid crystal compound, and is preferably a solvent that is inert 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, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1, 3-dimethyl-2-imidazolidinone. These solvents may be used alone, or 2 or more of them may be used in combination.

The content of the solvent is preferably 50 to 98% by mass based on the total amount of the composition (A). In other words, the solid content of the composition (a) is preferably 2 to 50 mass%. When the content of the solid component is 50% by mass or less, the viscosity of the composition (a) is low, and therefore the thickness of the polarizing layer is easily made substantially uniform. As a result, the polarizing layer tends not to be uneven. The content of the solid component may be determined in consideration of the thickness of the polarizing layer to be produced.

(reactive additive)

The composition (a) may comprise reactive additives. The reactive additive preferably has a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule. The "active hydrogen reactive group" herein means a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH-) -₂) A group reactive with a group having an active hydrogen, 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 are typical examples thereof. The number of carbon-carbon unsaturated bonds and active hydrogen reactive groups in the reactive additive is usually 1 to 20, preferably 1 to 10.

In the reactive additive, at least 2 active hydrogen reactive groups are preferably present, and in this case, the active hydrogen reactive groups present in plural may be the same or different.

The carbon-carbon unsaturated bond of the reactive additive may be a carbon-carbon double bond or a carbon-carbon triple bond, or a combination thereof, and is preferably a carbon-carbon double bond. Among them, as the reactive additive, a carbon-carbon unsaturated bond is preferably contained as the vinyl group and/or the (meth) acrylic group. The active hydrogen-reactive group is preferably a reactive additive that is at least 1 selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group, and more preferably a reactive additive having an acrylic group and an isocyanate group.

Specific examples of the reactive additive include compounds having a (meth) acrylic group and an epoxy group such as methacryloyloxyglycidyl ether and acryloyloxyglycidyl ether; compounds having a (meth) acrylic group and an oxetanyl group such as oxetanyl acrylate and oxetanyl methacrylate; compounds having a (meth) acrylic group and a lactone group such as a lactone acrylate and a lactone methacrylate; vinyl radical

Oxazoline, isopropenyl

Azolin and the like have a vinyl group and

an oxazoline-based compound; oligomers of a compound having a (meth) acrylic group and an isocyanate group, such as isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate, and the like. Further, compounds having a vinyl group, a vinylidene group, and an acid anhydride such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinylmaleic anhydride may be mentioned. Among them, preferred are methacryloyloxyglycidyl ether, acryloyloxyglycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, and vinyl

Oxazoline, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate and oligomers of the aforementioned substances, particularly preferably isocyanatomethyl acrylate, acrylic acid2-isocyanatoethyl ester and oligomers thereof.

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

[ in the formula (Y), n represents an integer of 1 to 10, R^1’Represents a 2-valent aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms or a 2-valent aromatic hydrocarbon group having 5 to 20 carbon atoms. 2R in each repeat unit^2’One of which is-NH-and the other is > N-C (═ O) -R^3’The group shown. R^3’Represents a group having a hydroxyl group or a carbon-carbon unsaturated bond.

R in the formula (Y)^3’At least one R of^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, may be referred to as compound (YY)) is particularly preferable (note that n represents the same meaning as described above).

The compound (YY) may be used as it is or may be purified as needed. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF corporation).

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

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

The moisture percentage of the base material layer is adjusted by heating or humidifying the base material layer. Heating the substrate layer is effective to adjust the modulus of elasticity of the laminate. When the substrate layer is heated, the heating temperature may be 50 to 150 ℃ and the heating time may be 1 to 10 minutes.

(coating method)

Examples of the method for applying the composition (a) to the substrate layer 11 or the alignment layer include the use of 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 printing method, a die coating method, an ink jet method, and the like. Further, there may be mentioned a method of coating with a coater such as a dip coater, a bar coater or a spin coater. Among them, when the coating is continuously performed in a Roll-to-Roll (Roll) manner, a coating method using a micro-gravure method, an ink-jet method, a slit coating method, or a die coating method is preferable, and when the coating is performed on a monolithic body such as glass, a spin coating method having high uniformity is preferable. In the case of coating in Roll to Roll form, the substrate layer 11 may be coated with an alignment polymer composition, a composition for forming a photo-alignment layer, or the like to form an alignment layer, and the composition (a) may be further continuously coated on the obtained alignment layer.

(drying method)

Examples of the drying method for removing the solvent contained in the composition (a) include natural drying, air drying, heat drying, drying under reduced pressure, and a combination thereof. Among them, natural drying or heat drying is preferable. The drying temperature is preferably in the range of 0 to 200 ℃, more preferably in the range of 20 to 150 ℃, and still more preferably in the range of 50 to 130 ℃. The drying time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. The composition for forming a photo-alignment layer and the alignment polymer composition may be dried in the same manner.

(polymerization method)

As a method of polymerizing the polymerizable liquid crystal compound, photopolymerization is preferable. The photopolymerization is performed by irradiating the composition (a) containing a polymerizable liquid crystal compound applied on the base material layer 11 or the alignment layer with an active energy ray. The active energy ray to be irradiated may be appropriately selected depending on the type of the polymerizable liquid crystal compound contained in the dry film (particularly, the type of the photopolymerizable functional group contained in the polymerizable liquid crystal compound), or, when the photopolymerization initiator is contained, depending on the type of the photopolymerization initiator and the amount thereof. Specifically, the active energy ray includes at least one light selected from the group consisting of visible light, ultraviolet light, infrared light, X-ray, α -ray, β -ray, and γ -ray. Among them, from the viewpoint of easy control of the progress of the polymerization reaction and the viewpoint of being able to use a device widely used in the art as a photopolymerization device, ultraviolet rays are preferable, and the type of polymerizable liquid crystal compound is preferably selected so that photopolymerization can be performed by ultraviolet rays.

Examples of the light source of the active energy ray include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light having a wavelength range of 380 to 440nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The ultraviolet irradiation intensity is usually 10mW/cm²～3000mW/cm². The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activation of the cationic polymerization initiator or the 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 still more preferably 0.1 second to 1 minute. When the ultraviolet ray is irradiated 1 or more times at such an ultraviolet irradiation intensity, the cumulative light amount is, for example, 10mJ/cm²～ 3000mJ/cm²Preferably 50mJ/cm²～2000mJ/cm²More preferably 100mJ/cm²～ 1000mJ/cm². When the cumulative light amount is less than the lower limit, the curing of the polymerizable liquid crystal compound may be insufficient, and good transferability may not be obtained.Conversely, when the cumulative light amount exceeds the upper limit value, the optical film including the optical hetero layer may be 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, and an electric field emission display device. The display device of the present embodiment has the stretchable laminated body 10, and thus can be preferably used for a stretchable display device, and particularly can be preferably used for an organic EL display device.

The present invention will be described in further detail below with reference to examples. In the examples, "%" and "part" are% by mass and "part by mass" unless otherwise specified.

Examples

[ tensile elastic modulus ]

Tensile modulus was measured in accordance with JIS K7161 by stretching the film in the absorption axis direction and the transmission axis direction using UTM (Universal Testing Machine, Autographics AG-X, Shimadzu corporation). The stretching conditions were a speed of 1.5 mm/min at normal temperature (temperature 23 ℃), a width of 40mm, and a punctuation distance of 50 mm.

[ Total haze value ]

The total haze value of the laminate before and after stretching in each stretching direction and stretching ratio was measured by a haze meter (HM-150, color technology research institute in mura, ltd.) according to JIS K7136. The absolute value of the difference between the total haze values of the laminate before and after stretching at each stretching ratio was represented by Δ H.

The total haze value can be calculated by the following formula.

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

[ visibility correcting monomer transmittance and visibility correcting polarization degree ]

For the laminates before and after stretching in the respective stretching directions and stretching ratios, the visibility-correcting monomer transmittance and the visibility-correcting polarization degree were measured using an ultraviolet-visible spectrophotometer (V7100, japan spectrographic co., ltd.) in accordance with jis z 8701, respectively. The absolute values of the differences between the visibility correction monomer transmittances and the visibility correction polarization degrees of the laminates before and after stretching at the respective stretching ratios were set to Δ T and Δ P, respectively.

[ Water content of base Material layer ]

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

Moisture percentage (%) of the base material layer was 100 × (W)_A－W_B－W_P)/(W_B－W₂)

W_P＝W₁－W₂

W_AThe weight of the sample vessel on which the substrate layer was placed.

W_BThe weight is the weight when the change with time of the water content becomes 0.02%/min or less by heating the sample dish on which the base material layer is placed at 120 ℃.

W₁Is the weight of the sample dish.

W₂The weight was measured when the sample vessel was heated at 120 ℃ and the change in water content with time was 0.02%/min or less.

W_PThe amount of surface moisture of the sample dish is reflected.

[ appearance evaluation ]

The laminate after stretching in each stretching direction and stretching ratio was evaluated for unevenness, cracks, haze and occurrence of cracks by visual observation.

O: no unevenness, no crack, no haze, and no occurrence of fracture

X: no unevenness, no crack, no haze, and no occurrence of fracture

X: generation of cracks, fractures, or unevenness

[ polymerizable liquid Crystal Compound ]

As the polymerizable liquid crystal compound, 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) ] were used.

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

As the dichroic dye, azo dyes described in examples of Japanese patent application laid-open No. 2013-101328 represented by the following formulae (2-1 a), (2-1 b) and (2-3 a) are used.

[ composition for Forming polarizing layer ]

The composition for forming a polarizing layer was prepared as follows: 75 parts by weight of the compound (1-6), 25 parts by weight of the compound (1-7), 2.5 parts by weight of each of the azo dyes represented by the above formulae (2-1 a), (2-1 b) and (2-3 a) 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-361N, manufactured by BYK-Chemie) as a leveling agent were mixed with 400 parts by weight of toluene in a solvent, and the resulting mixture was stirred at 80 ℃ for 1 hour.

[ Polymer 1]

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

The molecular weight of polymer 1 determined by GPC showed a number average molecular weight of 28200, Mw/Mn1.82, and a monomer content of 0.5%.

[ composition for Forming alignment layer ]

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

[ example 1]

A base material layer composed of triacetyl cellulose (TAC) having a thickness of 25 μm was prepared. The substrate layer was dried and heated at 120 ℃ for 5 minutes to reach a moisture content of 2%. The composition for forming an alignment layer was applied to the base material layer by a bar coating method, and the coating film was dried at 80 ℃ for 1 minute. The thickness was 100 nm.

Next, the resultant was irradiated with a UV irradiation device (SPOT CURE SP-7, manufactured by NIGHT MOTOR CO., LTD.) so that the cumulative light amount measured at a wavelength of 365nm was 100mJ/cm²The light of (2) was polarized by a wire grid (UIS-27132 # #, manufactured by NIU DENKO Co., Ltd.) to impart alignment ability, thereby obtaining an alignment layer.

The polarizing layer-forming composition was applied to the obtained alignment layer by a bar coating method. The coating film was dried by heating at 100 ℃ for 2 minutes, and then cooled to room temperature to obtain a dried film. Using a UV irradiation device (SPOT CURE SP-7) with a cumulative light amount of 1200mJ/cm²The obtained film was irradiated with ultraviolet light (365nm basis) to obtain a polarizing layer having a thickness of 3 μm. The obtained laminate was measured for tensile elastic modulus (E) in the absorption axis direction and the transmission axis direction_AAnd E_T). E of the laminate_AIs 3180MPa, E_T3900 MPa. In addition, the total haze value, the visibility-corrected individual transmittance, the visibility-corrected polarization degree, and the appearance were evaluated before stretching, after stretching at a stretch ratio of 5% in the absorption axis direction, and after stretching at a stretch ratio of 5% in the transmission axis direction, respectively. The results are shown in Table 1. Stretching was performed using UTM. The stretching conditions are that the speed is 1.5 mm/min, the width is 40mm and the punctuation distance is 50mm at normal temperature.

[ example 2]

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 10% in example 1.

[ example 3]

In example 1, the composition will be composed ofA laminate was produced in the same manner as in example 1, except that the substrate layer made of acetylcellulose (TAC) was changed to a substrate layer made of polyethylene terephthalate (PET). The thickness of the base layer made of PET was 50 μm. E of the laminate_AIs 4500MPa, E_T3300 MPa.

[ example 4]

A laminate was produced in the same manner as in example 3, except that the stretching ratio in the absorption axis direction and the stretching ratio in the transmission axis direction were each 10% in example 3.

Comparative example 1

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

Immersed in an aqueous solution containing potassium iodide and boric acid at 58 ℃ (potassium iodide/boric acid/water (weight ratio) ═ 12/3.2/100). The film was washed with pure water at 15 ℃ and then dried at 80 ℃ to obtain a polarizing layer having a thickness of about 12 μm in which iodine was adsorbed and oriented to polyvinyl alcohol. The stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching magnification was 5.5 times. A base material layer (trade name "KC 2 UA" manufactured by Konika & Nemada) made of a TAC film having a thickness of 25 μm was bonded to one surface of the obtained polarizing layer via an adhesive agent composed of an aqueous solution of a polyvinyl alcohol resin to prepare a polarizing plate. In the laminate, E_AIs 8500MPa, E_TIs 4950 MPa.

The obtained laminate was stretched at a stretching ratio of 5% in the absorption axis direction and at a stretching ratio of 5% in the transmission axis direction, and the tensile elastic modulus (E) was measured_AAnd E_T)。

In addition, the total haze value, the visibility-corrected monomer transmittance, the visibility-corrected polarization degree, and the 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 10%.

Comparative example 3

In comparative example 1, a laminate was produced in the same manner as in comparative example 1 except that a polyethylene terephthalate (PET) film (tomi corporation) was used instead of the TAC film having a thickness of 25 μm. The thickness of the PET film was 38 μm. E of the laminate_AIs 9900MPa, E_TIs 5100 MPa.

Comparative example 4

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

As shown in table 1, the laminates of examples 1 to 4 exhibited small differences in total haze, visibility-corrected monomer transmittance, and visibility-corrected polarization degree before and after stretching, and also exhibited good appearance after stretching. On the other hand, in comparative example 1, the difference between the visibility correction polarization degrees before and after stretching was large, and a sufficient result was not obtained in the appearance evaluation after stretching. In comparative example 2, breakage occurred during stretching. In comparative example 3, the differences among the total haze value, the visibility correcting monomer transmittance, and the visibility correcting polarization degree were large, and a sufficient result was not obtained in the appearance evaluation. In comparative example 4, unevenness occurred in the polarizing layer, and the appearance was deteriorated.

[ tensile test ]

After the reflectance was measured for the laminates produced in examples 5 and 6 and comparative example 5, the laminates were stretched at a rate of 5% elongation at a speed of 2.5 mm/min at a temperature of 60 ℃ by using UTM, and then the laminates were held in a stretched state, and the reflectance and the appearance were evaluated. In the measurement sample of each laminate, the length in the initial stretching direction was 50mm and the width was 40 mm. Tensile tests were performed for the case of stretching in the absorption axis direction (MD direction) and the transmission axis direction (TD direction), respectively.

The reflectance was measured by placing a sample for measurement and a reflecting plate (aluminum plate, reflectance 97%) in this order on a spectrophotometer (CM-2600 d, manufactured by Konika Minntau K.K., SCI model). The absolute value Δ reflectance [% ] of the difference between the reflectance [% ] measured before stretching and the reflectance [% ] measured while maintaining the stretched state was determined. The Δ reflectance [% ] can be obtained by the following formula.

Δ reflectance [% ] Y (before stretching) -Y (stretching state) & gt

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

Reflectance [% ] measured while keeping the stretched state as Y (stretched state)

Appearance evaluation unevenness, cracks/haze and occurrence or non-occurrence of fracture were evaluated by visual observation.

O: no unevenness, no crack, no haze, and no occurrence of fracture

X: no unevenness, no cracks, haze, and no occurrence of cracks

X: generation of cracks, fractures, or unevenness

[ production of coating type retardation layer with double-sided adhesive layer ]

(composition for Forming alignment film)

5 parts by mass (weight-average molecular weight: 30000) of a photo-alignment material having a structure represented by the following formula and 95 parts by mass of cyclopentanone (solvent) were mixed, and the resulting mixture was stirred at 80 ℃ for 1 hour, thereby obtaining an alignment film-forming composition.

(composition for Forming retardation layer)

A polymerizable liquid crystal compound A and a polymerizable liquid crystal compound B represented by the following formulas are mixed to form a mixture, wherein the mixture is represented by the formula (I) 90: 10 parts by mass of a leveling agent (F-556; available from DIC Co., Ltd.) and 6 parts by mass of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (IRGACURE369, available from BASF JAPAN) as a polymerization initiator were added to 100 parts by mass of the mixture. N-methyl-2-pyrrolidone (NMP) was further added so that the solid content concentration became 13%, and the mixture was stirred at 80 ℃ for 1 hour to obtain a composition for forming a retardation layer.

(polymerizable liquid Crystal Compound A)

(polymerizable liquid Crystal Compound B)

The polymerizable liquid crystal compound a is produced by the method described in jp 2010-31223 a. The polymerizable liquid crystal compound B is produced by the method described in jp 2009-173893 a.

(preparation of a laminate comprising a layer obtained by curing a substrate, an alignment film, and a polymerizable liquid Crystal Compound)

As a substrate, a cycloolefin resin film [ ZF-14-50, manufactured by Zeon corporation, Japan ] having a thickness of 50 μm was prepared and subjected to corona treatment. The corona-treated surface was coated with the composition for forming an oriented film by a bar coater. The coated film was dried at 80 ℃ for 1 minute. The dried coating film was irradiated with polarized UV light at an axial angle of 45 ℃ using a polarized UV irradiation apparatus (trade name "SPOT CURE SP-9" available from NIU DENKO Co., Ltd.) to obtain an alignment film. Irradiation with polarized light UV with a cumulative dose of 100mJ/cm at a wavelength of 313nm²Is carried out in the manner of (1).

Next, the composition for forming a retardation layer was coated on the alignment film using a bar coater. The coated film was dried at 120 ℃ for 1 minute. A high-pressure mercury lamp (trade name of oxtail motor corporation: the dried coating film was irradiated with ultraviolet light (IRGACUREWB-15201 BY-A').

The ultraviolet irradiation step is performed so that the cumulative light amount at a wavelength of 365nm becomes 400mJ/cm²The procedure of (1) is carried out under nitrogen atmosphere. In thatAfter the irradiation, the cured film was put into an oven set at 5 ℃ for 20 seconds as a cooling step. Immediately after the removal from the oven, the ultraviolet irradiation step and the cooling step were performed again (i.e., the total cumulative light amount of 2 times of ultraviolet irradiation was 800 mJ/cm)². ) A laminate comprising a substrate, an alignment film, and a layer obtained by curing a polymerizable liquid crystal compound was obtained.

The pressure-sensitive adhesive layer described later is laminated on the layer of the resultant laminate in which the polymerizable liquid crystal compound is cured. Next, the base material is peeled off from the laminate, and the pressure-sensitive adhesive layer is similarly laminated on the surface exposed by peeling.

In this way, a coating type retardation layer with a double-sided pressure-sensitive adhesive layer, which is composed of a pressure-sensitive adhesive layer, a layer in which a polymerizable liquid crystal compound is cured, an alignment film, and a pressure-sensitive adhesive layer, was prepared. The layer obtained by curing the polymerizable liquid crystal compound has a phase difference of lambda/4.

[ production of film-type retardation layer with double-sided adhesive layer ]

ZeonorFilm (Zeon corporation, in-plane retardation value for light having a wavelength of 550 nm: 138nm) which is a film obtained by uniaxially stretching a cycloolefin resin film was prepared. Adhesive layers described later are laminated on both surfaces of the film.

(adhesive layer)

By mixing butyl acrylate: 70 parts by mass of ethyl acrylate: 20 parts by mass of acrylic acid: 2.0 parts by mass and a radical polymerization initiator (2, 2' -azobisisobutyronitrile): 0.2 part by mass was reacted at 55 ℃ under nitrogen atmosphere with stirring to obtain an acrylic resin.

Mixing acrylic resin: 100 parts by mass of a crosslinking agent ("CORONATE L" manufactured by Tosoh corporation): 0.7 part by mass of a silane coupling agent (X-12-981, manufactured by shin-Etsu chemical Co., Ltd.): 0.5 parts by mass. Ethyl acetate was added so that the total solid content concentration became 10%, to obtain a pressure-sensitive adhesive composition.

The obtained adhesive composition was applied to the release-treated surface of the polyethylene terephthalate film (thickness: 38 μm) subjected to release treatment by an applicator so that the thickness after drying became 25 μm. The coating was dried at 100 ℃ for 1 minute to obtain a film having an adhesive layer. Thereafter, another polyethylene terephthalate film (38 μm in thickness) subjected to a mold release treatment was laminated on the adhesive layer. Thereafter, the mixture was aged at 23 ℃ and 50% RH relative humidity for 7 days.

< example 5 >

The above-described coating type retardation layer with a double-sided adhesive layer was bonded to the polarizing layer of the laminate composed of the base material layer/polarizing layer prepared in example 1 via one adhesive layer. The slow axis of the layer obtained by curing the polymerizable liquid crystal compound is 45 degrees with respect to the absorption axis of the polarizing layer. In this manner, a circularly polarizing plate comprising a base layer, a polarizing layer, a pressure-sensitive adhesive layer, a coating type retardation plate, and a pressure-sensitive adhesive layer was produced. The obtained circularly polarizing plate was subjected to a tensile test. The results are shown in Table 2.

< example 6 >

The polarizing layer of the substrate layer/polarizing layer laminate prepared in example 1 and the film-type retardation layer described above were bonded via an adhesive layer. The slow axis of the film type retardation layer was 45 degrees with respect to the absorption axis of the polarizing layer. In this manner, a circularly polarizing plate comprising a base layer, a polarizing layer, an adhesive layer, a film-type retardation layer, and an adhesive layer was produced. The obtained circularly polarizing plate was subjected to a tensile test. The results are shown in Table 2.

< comparative example 5 >

A circularly polarizing plate comprising a substrate, a polarizing layer, a pressure-sensitive adhesive layer, a coating type retardation layer and a pressure-sensitive adhesive layer was produced in the same manner as in example 5, except that the laminate comprising a substrate layer and a polarizing layer prepared in comparative example 4 was used. The obtained circularly polarizing plate was subjected to a tensile test. The results are shown in Table 2.

[ Table 2]

Description of the symbols

10 laminated body, 11 base material layer and 12 polarizing layer

Claims (8)

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

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

satisfies the following formula (1),

|E_A－E_T|/|E_A+E_T|≤0.25(1)

in the formula, E_AAnd E_TThe tensile moduli of elasticity in the absorption axis direction and in the transmission axis direction are shown, respectively.

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

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

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

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

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

7. The laminate according to claim 6, wherein a retardation layer is laminated via the adhesive layer.

8. A display device comprising an image display element and the laminate according to any one of claims 1 to 7 bonded thereto.

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