WO2020066910A1 - Layered body production method and optical member production method - Google Patents

Abstract

The purpose of the present invention is to provide a layered body production method that is excellent for transferring an optical layer containing a functional layer selected from the group consisting of a cholesteric liquid crystal layer and a phase contrast layer onto another substrate and also to provide an optical member production method. The present invention provides a layered body production method for producing a laminate comprising a temporary support and an optical layer disposed adjacently on the temporary support, said optical layer including a functional layer, wherein the method involves: a step for forming a precursor layer containing a liquid crystal compound having a polymerizable group directly on the temporary support or with another layer interposed therebetween; and a step for aligning the liquid crystal compound in the precursor layer, then curing the precursor layer by exposing the surface of the precursor layer on the opposite side from the temporary support to light in order to obtain the functional layer. The precursor layer contains the partial structure represented by formula (1), the light in the light exposure includes 265 nm-wavelength light, and the dose of the 265 nm-wavelength light is 5 mJ/cm2 or greater.

Description

Manufacturing method of laminated body, manufacturing method of optical member

<< The present invention relates to a method for manufacturing a laminate and a method for manufacturing an optical member.

A layer having a fixed cholesteric liquid crystal phase (hereinafter, also referred to as a “cholesteric liquid crystal layer”) is a layer having a property of selectively reflecting either right-handed circularly polarized light or left-handed circularly polarized light in a specific wavelength range. It is known and has been developed for various uses.
For example, Patent Document 1 discloses an embodiment in which a cholesteric liquid crystal layer is obtained by polymerizing a liquid crystal compound having a polymerizable group on a substrate.

JP 2013-200515 A

In recent years, thinning of products using a cholesteric liquid crystal layer has been used. Therefore, after forming the cholesteric liquid crystal layer on the support, it is desirable that only the cholesteric liquid crystal layer can be transferred onto the substrate.
The present inventors examined the transferability of the cholesteric liquid crystal layer disclosed in Patent Document 1, and found that the transferability of the cholesteric liquid crystal layer was poor due to poor adhesion to other substrates.
In addition to the cholesteric liquid crystal layer, there has been a similar demand for improvement in transferability of a retardation layer having a retardation. The retardation layer is a layer other than the cholesteric liquid crystal layer, and means a layer having a retardation in an in-plane direction or a thickness direction.

The present invention has been made in view of the above circumstances, and provides a method for producing a laminate, which is excellent in transferability of an optical layer including a functional layer selected from the group consisting of a cholesteric liquid crystal layer and a retardation layer to another substrate. That is the task.
Another object of the present invention is to provide a method for manufacturing an optical member.

The present inventors have conducted intensive studies on the above problems and found that the following structure can solve the above problems.

(1) a temporary support,
An optical layer disposed adjacently on the temporary support; and
The optical layer includes a functional layer selected from the group consisting of a cholesteric liquid crystal layer and a retardation layer,
In the optical layer, a functional layer is disposed at a position farthest from the temporary support, a method for manufacturing a laminate,
Forming a precursor layer containing a liquid crystal compound having a polymerizable group directly or through another layer on the temporary support,
After aligning the liquid crystal compound in the precursor layer, a step of irradiating the precursor layer with light from the surface of the precursor layer opposite to the temporary support side and performing a curing treatment to obtain a functional layer Has,
The precursor layer includes a partial structure represented by Formula (1) described below,
The light at the time of light irradiation includes light having a wavelength of 265 nm,
A method for producing a laminate, wherein the irradiation amount of light having a wavelength of 265 nm is 5 mJ / cm ² or more.
(2) the precursor layer further contains a surfactant,
The method for producing a laminate according to (1), wherein at least one of the liquid crystal compound and the surfactant has a partial structure.
(3) The method for producing a laminate according to (1) or (2), wherein the functional layer is a cholesteric liquid crystal layer.
(4) the precursor layer contains a chiral agent whose helical induction force changes by light irradiation,
The method according to (3), wherein the cholesteric liquid crystal layer has a pitch gradient structure in which a helical pitch changes in a thickness direction.
(5) The method for producing a laminate according to (4), wherein the cholesteric liquid crystal layer has a half width of an integral reflection spectrum of 80 nm or more.
(6) In any one of (1) to (5), in a cross section of the cholesteric liquid crystal layer observed by a scanning electron microscope, at least a part of a bright portion and a dark portion derived from the cholesteric liquid crystal phase has a wavy structure. A method for manufacturing a laminate.
(7) the precursor layer is disposed on the temporary support via another layer,
The method for producing a laminate according to any one of (1) to (6), wherein the other layer is a cholesteric liquid crystal layer.
(8) The method for producing a laminate according to (7), wherein the helical twist direction of the cholesteric liquid crystal layer as the functional layer is opposite to the helical twist direction of the other layer of the cholesteric liquid crystal layer.
(9) The method according to (7) or (8), wherein the cholesteric liquid crystal layer as another layer has a pitch gradient structure in which a helical pitch changes in a thickness direction.
(10) The optical layer in the laminate obtained by the production method according to any one of (1) to (9) is brought into contact with a substrate directly or via another layer to peel off the temporary support. And a step of obtaining an optical member including a base material and an optical layer.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the laminated body excellent in the transferability of the optical layer containing the functional layer selected from the group which consists of a cholesteric liquid crystal layer and a phase difference layer to another base material can be provided.
Further, according to the present invention, a method for manufacturing an optical member can be provided.

FIG. 3 is a schematic diagram for explaining a step 1-1. FIG. 9 is a schematic diagram for explaining a light irradiation method in a step 2. FIG. 4 is a schematic diagram for explaining a laminate obtained in a step 2. FIG. 3 is a schematic diagram for explaining a structure of a cholesteric liquid crystal layer. FIG. 3 is a schematic diagram for explaining a process 1-2.

Hereinafter, the present invention will be described in detail. In this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.

可視 In the present invention, visible light is light having a wavelength visible to the human eye among electromagnetic waves, and is light in a wavelength range of 380 to 780 nm. Ultraviolet light is light in a wavelength region of 10 nm or more and less than 380 nm.

特 徴 A feature of the manufacturing method of the present invention is that light including light having a wavelength of 265 nm is irradiated during the curing treatment of a precursor layer including a partial structure represented by the following formula (1). By irradiating the precursor layer with light having a wavelength of 265 nm, photo-fleece dislocation proceeds along with curing of the precursor layer. Examples of the optical Fries dislocation include dislocations represented by the following scheme.

部分 A partial structure having a phenolic hydroxyl group is formed by the occurrence of the optical fleece rearrangement. Therefore, a large number of partial structures having a phenolic hydroxyl group are generated on the surface of the functional layer on the light irradiation side, and as a result, the adhesion to other substrates is improved.

Hereinafter, the manufacturing method of the present invention will be described for each embodiment.
The first embodiment of the production method of the present invention represents an embodiment in which a precursor layer is formed directly on a temporary support, and the second embodiment of the production method of the present invention comprises another layer formed on a temporary support. Through which a precursor layer is formed.
Hereinafter, first, the first embodiment will be described in detail.

<< First Embodiment >>
The first embodiment of the production method of the present invention includes Step 1-1 and Step 2 described below.
Hereinafter, the procedure of each step will be described in detail.

<Step 1-1>
Step 1-1 is a step of forming a precursor layer containing a liquid crystal compound having a polymerizable group directly on the temporary support. By performing this step, a precursor layer that is a layer to be subjected to a curing treatment is formed. More specifically, by performing this step, the precursor layer 12 is formed directly on the temporary support 10 as shown in FIG.
Hereinafter, first, members and materials used in this step will be described in detail.

(Temporary support)
The temporary support is a substrate that supports the precursor layer, and adheres releasably to an optical layer described later. In other words, the temporary support is a peelable support. As described below, when the optical layer is transferred, it is separated into a temporary support and an optical layer.

The material constituting the temporary support is not particularly limited, and examples thereof include a polyester resin, a cellulose resin, a (meth) acrylic resin, a polycarbonate resin, a styrene resin, a polyolefin resin, a vinyl chloride resin, and an amide. Base resin.
In addition, (meth) acrylic resin is a general term for acrylic resin and methacrylic resin.

The temporary support may have a single-layer structure or a multilayer structure.
When the temporary support has a multilayer structure, the temporary support may include a substrate and a base layer including a resin disposed on the substrate. By providing an underlayer (especially, an underlayer that has not been subjected to rubbing treatment), a wavy structure, which will be described later, is easily formed in a cholesteric liquid crystal layer disposed on the surface of the underlayer.
In the above description, the underlayer is described as an example of the layer constituting the temporary support. However, as described later, the underlayer may be a part of the optical layer depending on the components constituting the underlayer.

The material constituting the substrate is not particularly limited, and examples thereof include the material constituting the support described above.
The thickness of the substrate is preferably from 20 to 1000 μm, more preferably from 40 to 500 μm.
The type of the resin contained in the underlayer is not particularly limited, and examples thereof include the materials constituting the temporary support described above. Above all, a (meth) acrylic resin is preferable as the resin contained in the underlayer.
The thickness of the underlayer is preferably 0.01 to 5.0 μm, more preferably 0.05 to 3.0 μm.
When the functional layer is a retardation layer, a temporary support having a rubbed surface may be used as the temporary support. Alternatively, the base layer may be an alignment layer (for example, a resin layer subjected to a rubbing treatment).

(Precursor layer)
The precursor layer is a layer disposed directly on the temporary support. As described later, in the second embodiment, the precursor layer is disposed on the temporary support via another layer.
The precursor layer contains a liquid crystal compound having a polymerizable group (hereinafter, also referred to as “polymerizable liquid crystal compound”).
The type of the polymerizable group is not particularly limited, and examples thereof include a radical polymerizable group and a cationic polymerizable group, and include a (meth) acryloyloxy group, a vinyl group, a maleimide group, an acetyl group, a styryl group, an allyl group, an epoxy group, and Oxetane group.
The (meth) acryloyloxy group is a general term for an acryloyloxy group and a methacryloyloxy group.
The number of polymerizable groups contained in the polymerizable liquid crystal compound is not particularly limited, and is preferably 1 to 6, more preferably 1 to 3.

The polymerizable liquid crystal compound may be a rod-shaped liquid crystal compound or a disc-shaped liquid crystal compound, but is preferably a rod-shaped liquid crystal compound. As the rod-shaped liquid crystal compound, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, Phenyldioxane, tolan or alkenylcyclohexylbenzonitrile are preferred.
As the liquid crystal compound, not only a low-molecular liquid crystal compound but also a high-molecular liquid crystal compound can be used.

The precursor layer includes a partial structure (phenyl ester structure) represented by the formula (1).
The partial structure represented by the formula (1) may be included in the polymerizable liquid crystal compound described above, or may be included in another compound. Other compounds include surfactants described below.

In the formula (1), R represents a substituent. The type of the substituent is not particularly limited, and may be a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, or a hetero group. Ring group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, amino group (including alkylamino group and anilino group), acylamino Group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group , Killed or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphine A finylamino group and a silyl group.
n1 represents an integer of 0 to 4, and n2 represents an integer of 0 to 4.
Among them, n1 is preferably from 0 to 2, and more preferably from 0 to 1. n2 is preferably 0 to 2, and more preferably 1.
n1 + n2 represents 4 or less. That is, the sum of n1 and n2 is 4 or less. Among them, 1-2 is preferable, and 1 is preferable.
* Represents a bonding position.

ＮIn the formula (1), n2 represents the number of bonding hands connected to the benzene ring. For example, when the partial structure represented by the formula (1) is a divalent group, n2 is 1, and the partial structure represented by the formula (2) (the divalent group represented by the formula (2)) ) May be contained in the compound.

In addition, as an example in which the partial structure represented by the above formula (1) (or the partial structure represented by the formula (2)) is included in the compound, for example, in the following compound, a broken line portion is a portion described above. Corresponds to the structure.

As the polymerizable liquid crystal compound having a partial structure represented by the formula (1), a compound represented by the formula (A) is preferable.
Formula (A) P ¹ -L ¹ -ML ² -P ²
In the formula (A), P ¹ and P ² each independently represent a hydrogen atom or a polymerizable group, and at least one of P ¹ and P ² represents a polymerizable group. The definition of the polymerizable group is as described above.

L ¹ and L ² each independently represent a single bond or a divalent linking group. The divalent linking group is not particularly limited. For example, any one selected from the group consisting of —O—, —CO—, —NR ^A —, —N ＝ CH—, and a divalent hydrocarbon group Species or a combination of two or more species (for example, -CO-O-, -O-2valent hydrocarbon group-, -O-2valent hydrocarbon group -O-,-(O-2valent Hydrogen group) _n3- (n3 represents an integer of 2 to 10)). ^RA represents a hydrogen atom or an alkyl group.
Examples of the divalent hydrocarbon group include an alkylene group, an alkenylene group (eg, —CH ＝ CH—), an alkynylene group (eg, —C≡C—), and an arylene group (eg, a phenylene group). No. The alkylene group may be linear, branched, or cyclic. The number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 4.

M represents a divalent mesogen group having a partial structure represented by the formula (2).
The mesogen group is a rigid and orientable functional group. The mesogen group may be a rod-shaped mesogen group or a disk-shaped mesogen group. Note that a rod-shaped mesogen group is intended to mean a mesogen group having a main skeleton portion that is linear, and a disc-shaped mesogen group is intended to mean a mesogen group having a structure in which the main skeleton portion is radially spread.
More specifically, as the structure of the mesogen group, a plurality of groups selected from the group consisting of an aromatic ring group (an aromatic hydrocarbon ring group and an aromatic heterocyclic group) and an alicyclic group, Valent linking group (for example, -CO-, -O-, -NR ^A- (R ^A represents a hydrogen atom or an alkyl group) or a combination thereof (-CO-O-)) Through the structure.
More specifically, the mesogen group includes a group represented by the formula (B).
Formula (B) — (L ³ −L ⁴ ) _m −
L ³ represents a divalent aromatic ring group which may have a substituent or a divalent alicyclic group which may have a substituent.
L ⁴ represents a single bond, —CO—, —O—, —NR ^A —, or a combination thereof (eg, —CO—O—). ^RA represents a hydrogen atom or an alkyl group. m represents an integer of 2 or more.
However, at least one of the m units represented by (L ³ -L ⁴ ) represents a partial structure represented by the formula (2).

The divalent aromatic ring group includes a divalent aromatic hydrocarbon ring group (for example, a phenylene group) and a divalent aromatic heterocyclic group.
Examples of the divalent alicyclic group include a cyclohexylene group.
The divalent aromatic ring group or the divalent alicyclic group may further have a substituent. The definition of the substituent is the same as the definition of the substituent represented by R in the formula (1).
m is preferably an integer of 2 to 5, more preferably an integer of 2 to 3.

The precursor layer may contain a compound other than the polymerizable liquid crystal compound.
The polymerizable liquid crystal compound may contain a surfactant.
As the surfactant, a surfactant containing a fluorine atom (fluorine surfactant) or a surfactant containing a silicon atom (silicon surfactant) is preferable, and a surfactant containing a fluorine atom is more preferable.
The surfactant is preferably a compound having at least two substituents containing a perfluoroalkyl group.
As the substituent containing a perfluoroalkyl group, a group represented by the formula (C) is preferable.
Formula (C) C _p F _{2p + 1} -L ^5- *
And L ⁵ represents a divalent linking group. The definition of the divalent linking group is the same as the definition of the divalent linking group represented by L ¹ and L ² . L ⁵ includes —CH ₂ —, —O—, —CO—, and a combination thereof (eg, —CO—O—, —O-2 divalent hydrocarbon group—, —O-2 divalent hydrocarbon). Hydrogen group —O—, — (O-2 valent hydrocarbon group) _n3 — (n3 represents an integer of 2 to 10), — (O—CO-2 valent hydrocarbon group) _n4 — (n4 Represents an integer of 1 to 10.)) is preferable.
p represents an integer of 1 or more. p is preferably an integer of 1 to 20, more preferably an integer of 1 to 10.
The surfactant preferably contains a benzene ring or a triazine ring.
The molecular weight of the surfactant is preferably 3000 or less, more preferably 2000 or less. The lower limit is not particularly limited, but is preferably 300 or more.

The surfactant preferably has a partial structure represented by the above formula (1).
As the surfactant, a compound represented by the formula (D) is preferable.
Formula ^{_{(D) (C p F 2p}} + 1 -L 5) q1 -Ar 1 - (L 6 -L 7) r -Ar 2 - (L 5 -C p F 2p + 1) q2
Definition in the formula (D), p and ^{L 5} is as described above.
Ar ¹ represents a q1 + 1 valent benzene ring. The benzene ring may have a substituent other than the group represented by (C _p F _{2p + 1} -L ⁵ ).
Ar ² represents a q2 + 1-valent benzene ring. The benzene ring may have a substituent other than the group represented by (C _p F _{2p + 1} -L ⁵ ).
L ⁶ represents a divalent aromatic ring group which may have a substituent or a divalent alicyclic group which may have a substituent. Examples of the divalent aromatic ring group include a divalent aromatic hydrocarbon ring group (for example, a phenylene group) and a divalent aromatic heterocyclic group. The divalent aromatic ring group or the divalent alicyclic group may further have a substituent. The definition of the substituent is the same as the definition of the substituent represented by R in the formula (1).
L ⁷ represents a single bond, —CO—, —O—, —NR ^A —, or a combination thereof (eg, —CO—O—). ^RA represents a hydrogen atom or an alkyl group. n represents an integer of 2 or more.
However, at least one of the r units represented by (L ⁶ -L ⁷ ) represents a partial structure represented by the formula (2).
r represents an integer of 1 to 3. Especially, 1 or 2 is preferable.
q1 and q2 each independently represent an integer of 1 to 5. Of these, an integer of 1 to 3 is preferred.

When the precursor layer contains a surfactant, the content of the surfactant in the precursor layer is not particularly limited, but is preferably 0.01 to 5% by mass relative to the total mass of the polymerizable liquid crystal compound. It is more preferably from 1 to 3% by mass.
One surfactant may be used alone, or two or more surfactants may be used.

The precursor layer may include a polymerization initiator.
As the polymerization initiator, a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation is preferable. Examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, phenazine compounds, oxadiazole compounds, and compounds having an oxime ester structure. Can be
When the precursor layer contains a polymerization initiator, the content of the polymerization initiator in the precursor layer is not particularly limited, but is preferably 0.1 to 20% by mass relative to the total mass of the polymerizable liquid crystal compound. -8% by mass is more preferred.
The polymerization initiator may be used alone or in combination of two or more.

The precursor layer may include a chiral agent. When the precursor layer contains a chiral agent, a cholesteric phase can be formed.
The type of chiral agent is not particularly limited. The chiral agent may be liquid crystalline or non-liquid crystalline. Chiral agents generally contain an asymmetric carbon atom. However, an axially asymmetric compound or a planar asymmetric compound containing no asymmetric carbon atom can also be used as a chiral agent. Examples of the axially asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. The chiral agent may have a polymerizable group.
As the chiral agent, a chiral agent whose helix inducing force changes by light irradiation (hereinafter, also referred to as a “photosensitive chiral agent”) is preferable. For example, a chiral agent whose helix inducing force is reduced by light irradiation, and a chiral agent whose helix inducing force is increased by light irradiation.
The spiral inducing force (HTP) of the chiral agent is a factor indicating the spiral orientation ability represented by the following formula (X).
Formula (X) HTP = 1 / (length of helical pitch (unit: μm) × concentration of chiral agent in precursor layer (% by mass)) [μm ⁻¹ ]
The length of the helical pitch refers to the length of the pitch P (= helical period) of the helical structure of the cholesteric liquid crystal phase, and can be measured by the method described on page 196 of a handbook of liquid crystals (published by Maruzen Co., Ltd.).

Examples of the photosensitive chiral agent include a so-called photoreactive chiral agent. The photoreactive chiral agent is a compound that has a chiral site and a photoreactive site that changes its structure by light irradiation, and that, for example, greatly changes the torsional force of the liquid crystal compound according to the amount of irradiation.
Examples of photoreactive sites whose structure is changed by light irradiation include photochromic compounds (Kingo Uchida, Masahiro Irie, Chemical Industries, vol. 64, 640p, 1999, Kingo Uchida, Masahiro Irie, Fine Chemical, vol. 28 (9), 15p) , 1999). Further, the above-mentioned structural change means a decomposition, an addition reaction, an isomerization, a dimerization reaction or the like caused by light irradiation to a photoreactive site, and the above-mentioned structural change may be irreversible. Examples of the chiral moiety include, for example, Hiroyuki Nohira, Chemical Review, No. The asymmetric carbon described in 22 Chemistry of Liquid Crystals, 73p: 1994, and the like correspond thereto.

As the photosensitive chiral agent, a compound having at least one photoisomerization site is preferable. As the photoisomerization site, the absorption of visible light is small, photoisomerization is likely to occur, and the helical induction force difference before and after light irradiation is large, so that a cinnamoyl site, a chalcone site, an azobenzene site, a stilbene site, Alternatively, a coumarin site is preferred, and a cinnamoyl site or chalcone site is more preferred.
Note that the photoisomerization site corresponds to a photoreaction site that changes its structure by light irradiation.

The precursor layer contains, in addition to the components described above, an antioxidant, an ultraviolet absorber, a sensitizer, a stabilizer, a plasticizer, a chain transfer agent, a polymerization inhibitor, an antifoaming agent, a thickener, a flame retardant, and a dispersant. And other additives such as coloring materials such as dyes and pigments.

(Procedure of Step 1-1)
The method for forming the precursor layer is not particularly limited, but from the viewpoint that the thickness of the precursor layer can be easily controlled, a composition for forming a precursor layer containing a predetermined component is coated on a temporary support, and A method of forming a precursor layer on a support is preferred.
Examples of the components contained in the precursor layer forming composition include the components that can be contained in the above-described precursor layer.
Note that the composition for forming a precursor layer may include a solvent. Solvents include water and organic solvents. Examples of the organic solvent include amides such as N, N-dimethylformamide; sulfoxides such as dimethyl sulfoxide; heterocyclic compounds such as pyridine; hydrocarbons such as benzene and hexane; alkyl halides such as chloroform and dichloromethane; Esters such as butyl acetate and propylene glycol monoethyl ether acetate; ketones such as acetone, methyl ethyl ketone, cyclohexanone and cyclopentanone; and ethers such as tetrahydrofuran and 1,2-dimethoxyethane.

方法 Examples of the method of applying the precursor layer forming composition include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method.

Note that, if necessary, a treatment for drying the precursor layer formed on the temporary support may be performed after the application of the composition for forming a precursor layer. By performing the drying treatment, the solvent can be removed from the precursor layer.

膜厚 The thickness of the precursor layer is not particularly limited, but is preferably 0.1 to 20 µm, more preferably 0.2 to 15 µm.

<Step 2>
In step 2, after aligning the liquid crystal compound in the precursor layer, the precursor layer is cured by irradiating light from the surface of the precursor layer opposite to the temporary support side to perform curing. This is the step of obtaining a layer. More specifically, after aligning the liquid crystal compound in the precursor layer, as shown in FIG. 2, from the surface 12a of the precursor layer 12 on the side opposite to the temporary support 10 side, indicated by white arrows. Thus, the precursor layer 12 is subjected to a curing treatment by irradiating light. As a result, as shown in FIG. 3, the functional layer 14 is formed on the temporary support 10, and the laminate 18A is obtained. As described above, in the vicinity of the surface 14a of the functional layer 14 on the side opposite to the temporary support 10 side, a large amount of phenolic hydroxyl groups are present due to photo-fleece rearrangement, and other groups on the surface 14a side of the functional layer 14 The adhesion to the material is improved.
Hereinafter, the procedure of this step will be described in detail.

The method of aligning the liquid crystal compound in the precursor layer is not particularly limited, and a method of performing a heat treatment on the precursor layer can be used. The conditions for the heat treatment vary depending on the type of the polymerizable liquid crystal compound and the components used, but the heating temperature is preferably from 10 to 250 ° C, more preferably from 50 to 150 ° C. The heating time is preferably 0.5 to 5 minutes, more preferably 0.5 to 2 minutes.
Note that the alignment state of the liquid crystal compound differs depending on the components used. When the precursor layer contains a chiral agent, the liquid crystal compound is cholesterically aligned. When a temporary support including an alignment layer is used as the temporary support and the precursor layer does not contain a chiral agent, the liquid crystal compound is homogeneously aligned.

Next, the precursor layer in which the liquid crystal compound is aligned is irradiated with light from the surface of the precursor layer on the side opposite to the temporary support side to perform a curing treatment.
Light applied to the precursor layer includes light having a wavelength of 265 nm. By irradiating the precursor layer with light having a wavelength of 265 nm, the above-mentioned optical Fries dislocation proceeds.
Irradiation amount of light of wavelength 265nm is at 5 mJ / cm ² or more, the optical Fries rearrangement proceeds better, in terms of further improving the transferability of the optical layer, 10 mJ / cm ² or more is preferable, 20 mJ / cm ^Two or more are more preferable. The upper limit is not particularly limited in terms of productivity, preferably 500 mJ / cm ² or less, 150 mJ / cm ² or less being more preferred.

The light applied to the precursor layer may include light having a wavelength of 265 nm, but ultraviolet light is preferable because curing of the precursor layer proceeds more favorably, and light (ultraviolet light) including light having a wavelength of 365 nm is preferable. More preferred.
The irradiation amount of light having a wavelength of 365 nm is preferably 20 mJ / cm ² or more, and more preferably 50 mJ / cm ² or more, from the viewpoint that curing of the precursor layer proceeds more favorably. The upper limit is not particularly limited, but is preferably 1500 mJ / cm ² or less from the viewpoint of productivity.

The temperature of the precursor layer during light irradiation is not particularly limited, and is preferably a temperature at which the alignment state of the liquid crystal compound is maintained, for example, preferably 10 to 250 ° C, and more preferably 20 to 150 ° C.

Through the steps 1-1 and 2 described above, a temporary support and a functional layer selected from the group consisting of a cholesteric liquid crystal layer and a retardation layer are provided adjacent to the temporary support. A laminate is formed. In this embodiment, the functional layer itself corresponds to the optical layer to be transferred. That is, the functional layer is transferred from the temporary support to another substrate.
As described later, the surface of the functional layer on the side opposite to the temporary support has many phenolic hydroxyl groups derived from photo-fleece rearrangement. Therefore, after the surface of the functional layer on the side opposite to the temporary support is brought into contact with the base material, the functional layer can be transferred onto the base material by peeling off the temporary support.

When the precursor layer contains a photosensitive chiral agent, the cholesteric liquid crystal layer formed through the above steps has a pitch gradient structure (hereinafter, also referred to as a “PG structure”) in which the helical pitch changes in the thickness direction. ) Is preferable.
For example, when a chiral agent having a lower helical inductive force than light irradiation is used as a photosensitive chiral agent, the helical pitch gradually increases in the cholesteric liquid crystal layer formed from the temporary support side toward the opposite side. I have. That is, in the cholesteric liquid crystal layer, the selective reflection wavelength (that is, the wavelength band of light selectively reflected) gradually increases from the temporary support side to the opposite side.
The reason why such a structure is obtained will be described below.
Usually, light applied to the precursor layer is absorbed by the material forming the precursor layer. Therefore, when the precursor layer is irradiated with light, the irradiation amount of light gradually decreases from the precursor layer side to the temporary support side. That is, the decrease in HTP of the chiral agent gradually decreases from the precursor layer side to the temporary support side. Therefore, in the region on the side opposite to the temporary support where the HTP has greatly decreased, the spiral pitch is long because the induction of the spiral is small, and in the region on the temporary support side where the decrease in HTP is small, the HTP originally contained in the chiral agent has , The spiral pitch is shortened.
That is, in this case, the cholesteric liquid crystal layer selectively reflects long-wavelength light on the side opposite to the temporary support, and selectively reflects short-wavelength light on the temporary support side as compared to the upper side. I do. Therefore, by using a cholesteric liquid crystal layer having a PG structure in which the helical pitch changes in the thickness direction, light in a wide wavelength band can be selectively reflected.

When the precursor layer contains a photosensitive chiral agent, the cholesteric liquid crystal layer formed through the above steps has a selective reflection wavelength, and a half-value width in a selective reflection wavelength band is patterned in a plane. You may.
For example, when a chiral agent having a lower helical induction force than light irradiation is used as a photosensitive chiral agent, an exposure mask or the like is used to pattern the amount of light irradiation at a wavelength that reduces the helical induction force of the photosensitive chiral agent. , A spiral pitch can be patterned in the plane. In this case, it is possible to form a cholesteric liquid crystal layer that selectively reflects long-wavelength light in a place where the light irradiation amount is large and selectively reflects short-wavelength light in a place where the light irradiation amount is small. Further, it is preferable to perform a curing treatment by irradiating light having a wavelength for curing the precursor layer.

The selective reflection wavelength of the cholesteric liquid crystal layer formed as the functional layer and the half width in a selective reflection wavelength band may be obtained by the following method.
That is, when the integrated reflectance is measured by a method described later, a peak-shaped (upwardly convex) integrated reflectance spectrum waveform with the wavelength on the horizontal axis is obtained. At this time, the average reflectance (arithmetic average) of the maximum value and the minimum value of the integrated reflectance is obtained, and of the two wavelengths at the two intersections of the waveform and the average reflectance, the value of the wavelength on the short wave side is λα (nm). , And the value of the wavelength on the long wave side is λβ (nm), and is calculated by the following equation.
Selective reflection wavelength = (λα + λβ) / 2
Half width = (λβ-λα)
Here, in the case of a sample having low diffuse reflectivity and strong specular reflectivity (specular reflectivity), the waveform of the integrated reflectance spectrum of the integrated reflectance may be distorted in a sawtooth shape. In such a case, the average reflectance (arithmetic average) of the maximum value and the minimum value of the specular reflectance is obtained from the spectrum waveform of the specular reflectance described above, and two wavelengths at two intersections of the waveform and the average reflectance are obtained. Of these, the selective reflection wavelength may be calculated by the above equation, where the wavelength value on the short wave side is λα (nm) and the wavelength value on the long wave side is λβ (nm).
As another method, a method of measuring a selective reflection wavelength and a half width by measuring a transmission spectrum of a sample with Axoscan of Axometrix or the like is exemplified. When the transmission spectrum is measured, a valley-shaped (convex downward) transmission spectrum waveform having the wavelength on the horizontal axis is obtained. At this time, the average reflectance (arithmetic average) of the maximum value and the minimum value of the transmittance is obtained, and of the two wavelengths at the two intersections of the waveform and the average transmittance, the value of the wavelength on the short wave side is λα (nm), By setting the value of the wavelength on the side to λβ (nm), the selective reflection wavelength and the half-value width are calculated by the above-described equations.
In addition, the integrated reflectance at the wavelength λ is measured by using a large integrating sphere device (manufactured by JASCO Corporation, ILV-471) with a spectrophotometer (manufactured by JASCO Corporation) so that light is incident on the cholesteric liquid crystal layer surface. What is necessary is just to measure with an optical trap using what was attached.

半 The FWHM of the integrated reflection spectrum of the cholesteric liquid crystal layer is not particularly limited, but is preferably 50 nm or more, more preferably 80 nm or more, and even more preferably 100 nm or more. The upper limit is not particularly limited, but is often 500 nm or less.

The cholesteric liquid crystal layer, which is a functional layer, has a cholesteric liquid crystal phase in a cross section observed with a scanning electron microscope (SEM), and has a bright portion B (bright line) and a dark portion D (dark line) in the thickness direction. Are observed alternately.
In the cholesteric liquid crystal layer, it is preferable that at least a part of a bright part and a dark part derived from a cholesteric liquid crystal phase have a wavy structure in a cross section observed by SEM.
That is, the cholesteric liquid crystal layer is preferably a layer having a cholesteric liquid crystal structure and a structure in which an angle between a helical axis and the surface of the cholesteric liquid crystal layer changes periodically. In other words, the cholesteric liquid crystal layer has a cholesteric liquid crystal structure, and the cholesteric liquid crystal structure gives a stripe pattern of a light portion B and a dark portion D in a cross-sectional view of the cholesteric liquid crystal layer observed by SEM, and a line formed by the dark portion. It is preferable that the angle formed between the normal line and the surface of the cholesteric liquid crystal layer changes periodically.
Preferably, the wavy structure includes at least one region M in which the absolute value of the inclination angle with respect to the plane of the cholesteric liquid crystal layer is 5 ° or more in a continuous line of the light portion B or the dark portion D forming a stripe pattern, and , Which has a peak or a valley having an inclination angle of 0 °, which is located closest to the region M in the plane direction.
The peak or the valley having an inclination angle of 0 ° includes a convex shape and a concave shape, but the inclination angle of 0 ° also includes a step-like and a shelf-like point. In the wavy structure, it is preferable that a plurality of regions M having an absolute value of the inclination angle of 5 ° or more and a plurality of peaks or valleys sandwiching the regions M are repeated in a continuous line of the light portion B or the dark portion D having a stripe pattern.

FIG. 4 conceptually shows a cross section of a cholesteric liquid crystal layer having a wavy structure and a PG structure.
As described above, as shown in FIG. 4, when the cross section of the cholesteric liquid crystal layer 14A is observed with an SEM, a stripe pattern of a bright portion B and a dark portion D is observed. That is, in the cross section of the cholesteric liquid crystal layer 14A, a layered structure in which light portions B and dark portions D are alternately stacked in the thickness direction is observed.
In the cholesteric liquid crystal layer 14A, two repetitions of the bright portion B and the dark portion D correspond to a helical pitch. From this, the helical pitch of the cholesteric liquid crystal layer, that is, the reflection layer, can be measured from the SEM sectional view. The two repetitions of the light part B and the dark part D are two light parts and two dark parts.
In the cholesteric liquid crystal layer 14A, since the bright part B and the dark part D have a wavy structure (undulation structure), when light is incident from the normal direction of the cholesteric liquid crystal layer 14A, the helical axis of the liquid crystal compound is inclined. Due to the region, a part of the incident light is reflected in an oblique direction.
That is, in the cholesteric liquid crystal layer 14A, since the bright portion B and the dark portion D have a wavy structure, a reflection layer having high diffuse reflection can be realized.

Note that the cholesteric liquid crystal layer having a wavy structure can be formed by forming a cholesteric liquid crystal layer on a formation surface that is not subjected to an alignment treatment such as rubbing. For example, a cholesteric liquid crystal layer having a wavy structure can be formed by forming a cholesteric liquid crystal layer using a temporary support including a base layer that has not been subjected to rubbing.
When a cholesteric liquid crystal layer is formed on an underlayer that is not subjected to an alignment treatment, the alignment direction of the liquid crystal compound varies in various directions on the surface of the underlayer according to the properties of the underlayer because there is no alignment control force for the liquid crystal compound. become. When the cholesteric liquid crystal layer is formed in such a state, the helical axes of the liquid crystal compound constituting the cholesteric liquid crystal phase are oriented in various directions, and as a result, the stripes of the bright portion B and the dark portion D have a wavy structure.

When the functional layer is a retardation layer, the in-plane retardation of the retardation layer is not particularly limited. However, when the retardation layer functions as a so-called λ / 4 plate, the in-plane retardation at a wavelength of 550 nm is 100 to 160 nm. Is preferred. When the retardation layer functions as a so-called λ / 2 plate, the in-plane retardation at a wavelength of 550 nm is preferably from 200 to 320 nm.

<< 2nd embodiment >>
The second embodiment of the production method of the present invention represents an embodiment in which a precursor layer is formed on a temporary support via another layer, as described above.
The second embodiment of the production method of the present invention includes the following steps 1-2 and 2.
Step 1-2: Forming a precursor layer containing a liquid crystal compound having a polymerizable group on the temporary support via another layer Step 2: After aligning the liquid crystal compound in the precursor layer, Step of irradiating the body layer with light from the surface of the precursor layer opposite to the side of the temporary support to perform a curing treatment to obtain a functional layer. Since it is the same as the first embodiment except that a layer is formed, the description is omitted below, and the difference between the two is mainly described below.

In step 1-2 of the second embodiment, a precursor layer is formed on the temporary support via another layer.
The type of the other layers is not particularly limited, and examples thereof include a cholesteric liquid crystal layer and a retardation layer. In addition to the above-mentioned layers, other layers include the above-described underlayer, adhesive layer, and pressure-sensitive adhesive layer. In addition, as described later, the other layer disposed on the temporary support is peeled off from the temporary support as a part of the optical layer and is transferred to the substrate.
When the other layer is a cholesteric liquid crystal layer, the cholesteric liquid crystal layer may have the PG structure described above. Further, in a cross section of the cholesteric liquid crystal layer observed by a scanning electron microscope, at least a part of a bright portion and a dark portion derived from the cholesteric liquid crystal phase may have a wavy structure.
When the other layer is a cholesteric liquid crystal layer and the functional layer is a cholesteric liquid crystal layer, the helical twist direction of the cholesteric liquid crystal layer, which is another layer, and the helical twist of the cholesteric liquid crystal layer, which is a functional layer, are different. The direction may be the opposite direction or the same direction, but the opposite direction is preferable in terms of excellent reflection characteristics.
Further, when the other layer is a cholesteric liquid crystal layer and the functional layer is a cholesteric liquid crystal layer, the selective reflection wavelength of the cholesteric liquid crystal layer as the other layer and the selective reflection wavelength of the cholesteric liquid crystal layer as the functional layer are different. Is preferably 400 nm or less.

The other layer may be a single layer or a multilayer. In the case of a multilayer, the layers constituting the multilayer may be the same type of layers (for example, cholesteric liquid crystal layers) or different types of layers (for example, a combination of a cholesteric liquid crystal layer and a retardation layer). You may.

方法 The method for forming the other layers is not particularly limited, and a known method is employed.

(5) By the above procedure, as shown in FIG. 5, a laminate 18B having the temporary support 10 and the other layers 16 and the functional layers 14 arranged on the temporary support 10 is obtained. In the laminate 18B, two layers of the other layer 14 and the functional layer 16 correspond to the optical layer 20 as a transfer object. That is, the optical layer is transferred from the temporary support to another substrate.

By the procedure of the first embodiment and the second embodiment described above, a laminate having a temporary support and an optical layer disposed adjacent to the temporary support is obtained.
In both the first embodiment and the second embodiment, in the optical layer, the functional layer is arranged at a position farthest from the temporary support.
Further, as described above, the surface of the functional layer opposite to the temporary support has many phenolic hydroxyl groups derived from photo-fleece rearrangement.
Therefore, by bringing the surface of the optical layer (specifically, the surface of the functional layer opposite to the temporary support side) into contact with the base material directly or through another layer, the temporary support is peeled off. Thus, an optical member including the substrate and the optical layer can be obtained. More specifically, in the laminate 18A shown in FIG. 3, after the surface 14a of the functional layer 14 corresponding to the optical layer is brought into contact with the base material directly or through another layer, the temporary support 10 By peeling off, an optical member including the substrate and the optical layer can be obtained. In the laminate 18B shown in FIG. 5, after the surface 20a of the optical layer 20 including the functional layer 14 and the other layer 16 is brought into contact with the base material directly or through another layer, the optical layer 20 By peeling off the temporary support 10 at the interface between the temporary support 10 and the temporary support 10, an optical member including the base material and the optical layer can be obtained. Note that, in the embodiment of FIG. 5, the embodiment in which the number of the optical layers is two has been described. However, the number of the optical layers may be three or more. Corresponds to multiple layers. As a method of forming three or more optical layers, there is a method of forming a precursor layer on a temporary support via two other layers.
As described above, the other layers include a cholesteric liquid crystal layer, a retardation layer, a base layer, an adhesive layer, and a pressure-sensitive adhesive layer. When another layer is arranged on the temporary support, the other layer is transferred onto the base material as a part of the optical layer.

The functional layer can be applied to various uses. For example, when the functional layer is a cholesteric liquid crystal layer, various uses such as a decorative sheet, a light reflecting member, a light diffusing plate, a half mirror, a transparent screen, an imaging device, a sensor, an optical device, and other optical devices. Available to For example, the functional layer in the laminate manufactured by the manufacturing method of the present invention can be used for an optical device having a functional layer and an element using light transmitted through the functional layer.
There is no particular limitation on an element utilizing light transmitted through the functional layer, and various elements such as an imaging element and a sensor can be used. At this time, for example, the laminated body produced by the production method of the present invention is bonded to an optical filter such as an SC filter (manufactured by FUJIFILM Corporation) and an IR filter (manufactured by FUJIFILM Corporation), and the temporary support is peeled off. Thus, the functional layer may be used as a decorative sheet. This makes it possible to decorate the device such as an image sensor and a sensor according to the light receiving wavelength.

Further, an image display device may be formed by using a functional layer in the laminate manufactured by the manufacturing method of the present invention and an image display element.
Various known image display elements can be used as the image display element. As an example, a liquid crystal display element and an organic electroluminescence display element are exemplified.

機能 Further, the functional layer in the laminate produced by the production method of the present invention can also be used as an optical element. For example, it can be used for a general use as a half mirror and for a use described in paragraph 0017 of JP-A-2017-092021.

本 Hereinafter, the present invention will be described in more detail with reference to Examples. Materials, used amounts, ratios, processing details, and processing procedures shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

<Comparative Example 1>
(Preparation of Underlayer 1)
As a substrate having a thickness of 50 μm, PET (polyethylene terephthalate) (Cosmoshine A4100, manufactured by Toyobo Co., Ltd.) was prepared and used as the transparent support 1. In addition, the transparent support 1 corresponds to a so-called temporary support.
The underlayer coating solution 1 having the following composition was applied to the surface of the transparent support 1 on which the easy-adhesion layer was not provided by a # 3.6 wire bar coater. Thereafter, the transparent support 1 on which the underlayer coating solution 1 has been applied is dried at 45 ° C. for 60 seconds, and the transparent support 1 subjected to the above-mentioned drying treatment is applied at 25 ° C. using an ultraviolet irradiation device at 500 mJ / cm. by irradiating the ^second ultraviolet, to prepare a base layer with the transparent support 1.

(Underlayer coating solution 1)
KAYARAD PET30 (manufactured by Nippon Kayaku Co., Ltd.) 100 parts by mass IRGACURE 907 (manufactured by Ciba Geigy) 3.0 parts by mass Kayakur DETX (manufactured by Nippon Kayaku Co., Ltd.) 1.0 parts by mass Surfactant F10 having the following structure .01 parts by mass 243 parts by mass of methyl isobutyl ketone

Surfactant F1 (hereinafter, structural formula)

(Production of Cholesteric Liquid Crystal Layer Ch1)
The components shown below were stirred in a container kept at 25 ° C. to prepare a cholesteric liquid crystal layer coating liquid Ch1.

(Coating liquid Ch1 for cholesteric liquid crystal layer)
Methyl ethyl ketone 125.0 parts by mass Cyclohexanone 18.7 parts by mass Mixture of the following rod-shaped liquid crystal compounds 100.0 parts by mass IRGACURE 907 (manufactured by Ciba Geigy) 0.0375 parts by mass Kayacure DETX (manufactured by Nippon Kayaku Co., Ltd.) 0.0125 Parts by mass 6.06 parts by mass of chiral agent B having the following structure 0.027 parts by mass of surfactant F1 having the above structure 0.067 parts by mass of surfactant F2 having the following structure

Rod-shaped liquid crystal compound (hereinafter, structural formula)

Values are% by mass. R is a group bonded by an oxygen atom.

Chiral agent B (hereinafter, structural formula)

Chiral agent B is a chiral agent that forms a right-handed spiral. Chiral agent B is a chiral agent having a cinnamate group.

Surfactant F2

The cholesteric liquid crystal layer coating liquid Ch1 prepared above was applied to the upper surface of the underlayer of the transparent support 1 with an underlayer using a # 12 wire bar coater. Thereafter, the transparent support 1 with an underlayer coated with the cholesteric liquid crystal layer coating solution Ch1 is dried at 105 ° C. for 60 seconds, and at a oxygen concentration of 200 ppm or less and a short wavelength cut filter (TEMPAX, manufactured by SCHOTT) at 85 ° C. The cholesteric liquid crystal layer Ch1 was produced by irradiating an ultraviolet ray from a high-pressure mercury lamp having an irradiation amount of 365 nm at a wavelength of 459 mJ / cm ² and an irradiation amount of a wavelength of 265 nm at 2.4 mJ / cm ² .

(Production of Cholesteric Liquid Crystal Layer Ch2)
The components shown below were stirred in a container kept at 25 ° C. to prepare a cholesteric liquid crystal layer coating liquid Ch2.

(Coating liquid Ch2 for cholesteric liquid crystal layer)
Methyl ethyl ketone 132.4 parts by mass Cyclohexanone 19.8 parts by mass Mixture of the above-mentioned rod-shaped liquid crystal compound 100.0 parts by mass Kayacure DETX (manufactured by Nippon Kayaku Co., Ltd.) 0.5 parts by mass Chiral agent C having the following structure 11.87 parts by mass 0.027 parts by mass of surfactant F1 having the above structure 0.067 parts by mass of surfactant F2 having the above structure

Chiral agent C (hereinafter, structural formula)

Chiral agent C is a chiral agent that forms a left-handed spiral. The chiral agent C is a chiral agent having a cinnamate group.

The cholesteric liquid crystal layer coating solution Ch2 prepared above was applied onto the cholesteric liquid crystal layer Ch1 with a # 5 wire bar coater. Thereafter, the transparent support 1 with the underlayer coated with the cholesteric liquid crystal layer coating solution Ch2 is dried at 105 ° C. for 60 seconds, and at a oxygen concentration of 200 ppm or less and at 85 ° C., a short wavelength cut filter (TEMPAX, shot Cholesteric liquid crystal layer Ch2 was produced by irradiating an ultraviolet ray from a high-pressure mercury lamp having an irradiation amount of 365 nm at a wavelength of 459 mJ / cm ² and an irradiation amount of a wavelength of 265 nm at 2.4 mJ / cm ^2. The laminate of Example 1 was produced.

<Comparative Example 2>
Ultraviolet irradiation of the cholesteric liquid crystal layer Ch2, without passing through the filter, except that dose of wavelength 365nm is 50 mJ / cm ^2, irradiation amount of wavelength 265nm is an ultraviolet radiation of a high-pressure mercury lamp is 3.8mJ / cm ² is A cholesteric liquid crystal layer Ch2 was produced in the same manner as in Comparative Example 1, and a laminate of Comparative Example 2 was produced.

<Example 1>
Ultraviolet irradiation of the cholesteric liquid crystal layer Ch2, without passing through the filter, except that dose of wavelength 365nm is an ultraviolet radiation of a high-pressure mercury lamp 100 mJ / cm ^2, irradiation amount of wavelength 265nm is 7.7mJ / cm ² is A cholesteric liquid crystal layer Ch2 was produced in the same manner as in Comparative Example 1, and a laminate of Example 1 was produced.

<Example 2>
Ultraviolet irradiation of the cholesteric liquid crystal layer Ch2, without passing through the filter, except that dose of wavelength 365nm is 500 mJ / cm ^2, irradiation amount of wavelength 265nm is an ultraviolet radiation of a high-pressure mercury lamp is 38.3mJ / cm ² is A cholesteric liquid crystal layer Ch2 was produced in the same manner as in Comparative Example 1, and a laminate of Example 2 was produced.

<Evaluation>
The following table shows the results of evaluation using each of the laminates produced in the examples and comparative examples.
In Examples 1 and 2, the optical layer to be transferred includes an underlayer, a cholesteric liquid crystal layer Ch1, and a cholesteric liquid crystal layer Ch2.

(Releasability)
PET (Cosmoshine A4100, manufactured by Toyobo Co., Ltd.) is prepared as a transfer substrate, and the cholesteric liquid crystal layer Ch2 of the laminate is applied with an adhesive (SK-2057, manufactured by Soken Chemical Co., Ltd.). The number of defects when the transparent support 1 was peeled off at a speed of 5 m per minute in a direction of 180 degrees was evaluated from the following viewpoint. Table 1 shows the results.
A: 0 to 1 defect per square meter due to defective peeling.
B: 2 to 5 defects per square meter due to defective peeling.
C: 6 or more defects per square meter due to defective peeling.
Here, those which are peeled off without remaining at the interface between the transparent support 1 and the underlayer are regarded as having zero defects due to defective peeling per square meter. The defect due to the peeling defect means that the optical layer to be transferred is not separated at the interface between the transparent support 1 and the underlayer but at another interface (for example, the interface between the adhesive and the cholesteric liquid crystal layer Ch2). It refers to the portion left on the transparent support 1 side.

In Table 1, the column “irradiation amount 365 nm (mJ / cm ² )” indicates the irradiation amount of light having a wavelength of 365 nm.
The “irradiation amount 265 nm (mJ / cm ² )” column indicates the irradiation amount of light having a wavelength of 265 nm.
The “PG structure” column indicates the presence or absence of a PG structure in the obtained cholesteric liquid crystal layer, and indicates “A” when the cholesteric liquid crystal layer has a PG structure and “B” when the cholesteric liquid crystal layer does not.
The “wavy structure” column indicates the presence or absence of a wavy structure of the obtained cholesteric liquid crystal layer, where “A” indicates that the cholesteric liquid crystal layer has a wavy structure, and “B” indicates that the cholesteric liquid crystal layer does not.

As shown in the above table, according to the production method of the present invention, a laminate having a desired effect was obtained.
In particular, it was confirmed that the effect was more excellent when the irradiation amount of light having a wavelength of 265 nm was 10 mJ / cm ² or more.

DESCRIPTION OF SYMBOLS 10 Temporary support 12 Precursor layer 14 Functional layer 14A Cholesteric liquid crystal layer 16 Other layers 18A, 18B Laminate 20 Optical layer

Claims (10)

A temporary support,
An optical layer disposed adjacent to the temporary support,
The optical layer includes a functional layer selected from the group consisting of a cholesteric liquid crystal layer and a retardation layer,
In the optical layer, the functional layer is disposed at a position farthest from the temporary support, a method for manufacturing a laminate,
Forming a precursor layer containing a liquid crystal compound having a polymerizable group, directly or through another layer on the temporary support,
After aligning the liquid crystal compound in the precursor layer, the precursor layer is subjected to curing treatment by irradiating light from the surface of the precursor layer opposite to the temporary support side, Having a step of obtaining a functional layer,
The precursor layer includes a partial structure represented by Formula (1),
The light at the time of the light irradiation includes light having a wavelength of 265 nm,
The method for producing a laminate, wherein the irradiation amount of the light having the wavelength of 265 nm is 5 mJ / cm ² or more.

In the formula (1), R represents a substituent. n1 represents an integer of 0 to 4, n2 represents an integer of 0 to 4, and n1 + n2 represents 4 or less. * Represents a bonding position. The precursor layer further contains a surfactant,
The method for producing a laminate according to claim 1, wherein at least one of the liquid crystal compound and the surfactant has the partial structure. The method according to claim 1 or 2, wherein the functional layer is a cholesteric liquid crystal layer. The precursor layer contains a chiral agent whose helical induction force changes by the light irradiation,
The method for manufacturing a laminate according to claim 3, wherein the cholesteric liquid crystal layer has a pitch gradient structure in which a helical pitch changes in a thickness direction. The method for producing a laminate according to claim 4, wherein the cholesteric liquid crystal layer has a half-width of an integral reflection spectrum of 80 nm or more. The laminate according to any one of claims 1 to 5, wherein in a cross section of the cholesteric liquid crystal layer observed by a scanning electron microscope, at least a part of a bright portion and a dark portion derived from a cholesteric liquid crystal phase has a wavy structure. How to make the body. The precursor layer is disposed on the temporary support via the other layer,
The method according to any one of claims 1 to 6, wherein the other layer is a cholesteric liquid crystal layer. 8. The method of manufacturing a laminate according to claim 7, wherein the helical twist direction of the cholesteric liquid crystal layer serving as the functional layer is opposite to the helical twist direction of the cholesteric liquid crystal layer serving as the other layer. The method according to claim 7 or 8, wherein the cholesteric liquid crystal layer as the other layer has a pitch gradient structure in which a helical pitch changes in a thickness direction. The optical layer in the laminate obtained by the production method according to any one of claims 1 to 9 is brought into contact with a substrate directly or via another layer, and the temporary support is peeled off. A method for manufacturing an optical member, comprising a step of obtaining an optical member including the substrate and the optical layer.

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