Method for producing cholesteric liquid crystal layer, cholesteric liquid crystal layer, reflective film, laminated glass, head-up display system, and composition

Abstract

The first problem of the present invention is to provide a method for producing a cholesteric liquid crystal layer, with which it is possible to easily produce a cholesteric liquid crystal layer in which the reflection spectrum is not susceptible to change when heat treatment is performed in a state in which adjacent layers are arranged on the surface of the cholesteric liquid crystal layer. A second subject of the present invention is to provide a cholesteric liquid crystal layer, a reflective film, laminated glass, a head-up display system, and a composition. A method for producing a cholesteric liquid crystal layer according to the present invention comprises: a step 1 for forming a composition layer containing a liquid crystal compound having a polymerizable group, and a first polymerizable chiral reagent and a second polymerizable chiral reagent, the helical twisting force of which changes as a result of light irradiation; a step 2 for aligning the liquid crystal compound; a step 3 for irradiating, under predetermined conditions, light having a wavelength capable of changing the helical twisting force of the first polymerizable chiral reagent; and a step (4) for forming a cholesteric liquid crystal layer by subjecting the composition layer to a curing treatment, in which the composition layer is subjected to a heat treatment between the step (3) and the step (4) or in the step (3).

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of a cholesteric liquid crystal layer, a cholesteric liquid crystal layer, a reflective film, a laminated glass, a head-up display system, and a composition. BACKGROUND

[0002] In recent years, as one of vehicle-mounted displays, a so-called head-up display system that projects various information as an image onto a windshield or the like by a projector and transmits it to a driver has been developed.

[0003] As a head-up display system, for example, a head-up display system in which a reflective film including a cholesteric liquid crystal layer that exhibits circularly polarized light selective reflection is assembled to a windshield is known. Also, the cholesteric liquid crystal layer is provided with a reflection spectrum having a wide reflection band throughout the visible region, and thus is typically configured by laminating a plurality of cholesteric liquid crystal layers having different central reflection wavelengths (in other words, different in the size of the helical pitch of the liquid crystal compound) in multiple layers. In addition, in the manufacturing process of assembling the reflective film to the windshield, a process of laminating the reflective film and the glass constituting the windshield via an adhesive layer (OCA (Optical Clear Adhesive) layer) or a heat-seal layer, and applying a heat treatment to the laminate is typically performed.

[0004] However, for example, in Patent Literature 1, a simple manufacturing method of an optically anisotropic layer in which the orientation state of a liquid crystal compound is fixed and which has a plurality of regions different in the orientation state of the liquid crystal compound in the thickness direction is disclosed. More specifically, a method of simultaneously molding a laminate having two optically anisotropic layers composed of a rod-shaped liquid crystal composition in one coating process is disclosed.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: International Publication No. 2022 / 030266 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] The present inventors and others have studied a manufacturing method of a cholesteric liquid crystal layer in which a plurality of regions different in the helical pitch are formed in the thickness direction, with reference to the manufacturing method of the optically anisotropic layer described in Patent Literature 1, and as a result, it has been clarified that when a heat treatment is performed in a state in which an adjacent layer such as an adhesive layer or a heat-seal layer is disposed on the surface of the obtained cholesteric liquid crystal layer, the reflection spectrum of the cholesteric liquid crystal layer changes before and after heating, and sometimes the reflected light of the desired color tone cannot be obtained.

[0010] Thus, an object of the present application is to provide a method for producing a cholesteric liquid crystal layer which can easily produce a cholesteric liquid crystal layer which is less likely to change the reflection spectrum when a heating treatment is performed in a state where an adjacent layer is disposed on the surface thereof.

[0011] Further, an object of the present application is to provide a cholesteric liquid crystal layer, a reflective film, a laminated glass, a head-up display system, and a composition.

[0012] Means for solving the technical problem

[0013] The present inventors have found that the above objects can be solved by the following structure.

[0014] (1) A method for producing a cholesteric liquid crystal layer, comprising:

[0015] Step 1, forming a composition layer containing a liquid crystal compound having a polymerizable group, a first polymerizable chiral agent which changes a helical twisting power by light irradiation, and a second polymerizable chiral agent having a chirality opposite to that of the first polymerizable chiral agent;

[0016] Step 2, aligning the liquid crystal compound in the composition layer;

[0017] Step 3, irradiating light of a wavelength capable of changing the helical twisting power of the first polymerizable chiral agent under a condition where the oxygen concentration is 1% by volume or more; and

[0018] Step 4, performing a curing treatment on the composition layer to fix the alignment state of the liquid crystal compound, thereby forming a cholesteric liquid crystal layer having a plurality of regions with different helical pitches in the thickness direction,

[0019] Between Step 3 and Step 4, there is Step 5 of performing a heating treatment on the composition layer, or in Step 3, a heating treatment is further performed on the composition layer at the time of light irradiation.

[0020] (2) The method for producing a cholesteric liquid crystal layer according to (1), wherein

[0021] The first polymerizable chiral agent and the second polymerizable chiral agent each have two or more polymerizable groups.

[0022] (3) The method for producing a cholesteric liquid crystal layer according to (1) or (2), wherein

[0023] The first polymerizable chiral agent and the second polymerizable chiral agent contain a partial structure selected from the group consisting of an isosorbide partial structure, an isomannite partial structure, and a binaphthalene partial structure.

[0024] (4) The method for producing a cholesteric liquid crystal layer according to any one of (1) to (3), wherein

[0025] The first polymerizable chiral reagent has a double bond capable of photoisomerization in the molecule.

[0026] (5) The method for producing a cholesteric liquid crystal layer according to any one of (1) to (4), wherein

[0027] The first polymerizable chiral reagent contains a photoisomerization site selected from the group consisting of a cinnamoyl site, a chalcone site, and a stilbene site.

[0028] (6) The method for producing a cholesteric liquid crystal layer according to any one of (1) to (5), wherein

[0029] The cholesteric liquid crystal layer has a thickness of 10 μm or less.

[0030] (7) A cholesteric liquid crystal layer which is fixed in a cholesteric liquid crystal phase, wherein

[0031] has a plurality of regions with different helical pitch in the thickness direction,

[0032] The cholesteric liquid crystal layer is a layer formed using a composition containing a liquid crystal compound having a polymerizable group, a first polymerizable chiral reagent whose helical twisting power changes by light irradiation, and a second polymerizable chiral reagent having a handedness opposite to that of the first polymerizable chiral reagent.

[0033] (8) A reflective film having the cholesteric liquid crystal layer according to (7).

[0034] (9) A reflective film sequentially having a first phase difference layer, the cholesteric liquid crystal layer according to (7), and a second phase difference layer.

[0035] (10) The reflective film according to (9), wherein

[0036] The average of the reflectance at an incident angle of 5° and a wavelength of 400 to 800 nm is 15% or less.

[0037] (11) The reflective film according to (9) or (10), wherein

[0038] The average transmittance at a wavelength of 380 to 420 nm is 50% or more.

[0039] (12) A laminated glass sequentially having a first glass sheet, the reflective film according to any one of (8) to (11), and a second glass sheet.

[0040] (13) The laminated glass according to (12), wherein

[0041] A heat-sealing layer or an adhesive layer is provided between the first glass plate and the reflective film or between the second glass plate and the reflective film.

[0042] (14) A laminated glass having, in order, a first glass plate, an interlayer film, a second glass plate, and the reflective film according to any one of (8) to (11).

[0043] (15) The laminated glass according to (14), wherein

[0044] A heat-sealing layer or an adhesive layer is provided between the first glass plate and the reflective film or between the second glass plate and the reflective film.

[0045] (16) A head-up display system having: a windshield composed of the laminated glass according to any one of (12) to (15); and a projector that irradiates the windshield with projection light.

[0046] (17) The head-up display system according to (16), wherein

[0047] The projector irradiates the projection light of P-polarized light.

[0048] (18) A composition comprising: a liquid crystal compound having a polymerizable group; a first polymerizable chiral reagent that changes in helical twisting power by light irradiation; and a second polymerizable chiral reagent having a chirality in the opposite direction to the first polymerizable chiral reagent.

[0049] Effects of the Invention

[0050] According to the present application, it is possible to provide a manufacturing method of a cholesteric liquid crystal layer that can easily manufacture a cholesteric liquid crystal layer that does not easily change in reflection spectrum when performing a heat treatment in a state where an adjacent layer is disposed on the surface thereof.

[0051] Further, according to the present application, it is possible to provide a cholesteric liquid crystal layer, a reflective film, a laminated glass, a head-up display system, and a composition. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 is a cross-sectional view of a composition layer for illustrating an example of Step 2 of the manufacturing method of the cholesteric liquid crystal layer of the present application.

[0053] Figure 2 is a schematic view of a graph showing a relationship between helical twisting power (pm -1 ) x concentration (mass%) and light irradiation amount (mJ / cm 2 ) plotted for the first polymerizable chiral reagent and the second polymerizable chiral reagent, respectively.

[0054] Figure 3A schematic view of a graph plotting the weighted average helical twisting power (μm -1 ) of the first and second polymeric chiral agents against the light irradiation amount (mJ / cm 2 ).

[0055] Figure 4 is a cross-sectional view of a composition layer for illustrating an example in which the composition layer 12 after the light irradiation of Step 3 is subjected to Step 5.

[0056] Figure 5 A schematic view of a graph plotting the weighted average helical twisting power (μm -1 ) of the first and second polymeric chiral agents against the light irradiation amount (mJ / cm 2 ).

[0057] Figure 6 is a cross-sectional schematic view showing an example of the structure of a reflective film.

[0058] Figure 7 is a cross-sectional schematic view showing another example of the structure of a laminated glass.

[0059] Figure 8 is a cross-sectional schematic view showing another example of the structure of a laminated glass.

[0060] Figure 9 is a schematic view showing an example of the structure of a head-up display. DETAILED DESCRIPTION

[0061] Hereinafter, the present application will be described in detail. In the present specification, a numerical range represented by "to" indicates a range including values recited before and after "to" as lower limit values and upper limit values. First, terms used in the present specification will be described.

[0062] Unless otherwise specifically stated, "light" in the description of the manufacturing method in the present specification refers to an active light ray or a radiation ray, such as, for example, a bright line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, extreme ultraviolet (EUV light), X-rays, ultraviolet rays, and electron beams (EB), and the like. Among these, ultraviolet rays are preferred.

[0063] Unless otherwise specifically stated, "light" in the description of parts other than the manufacturing method in the present specification refers to light of visible light and natural light (unpolarized light).

[0064] In the present specification, "visible light" refers to light in the wavelength region of 380 to 780 nm. Also, in the present specification, unless otherwise specifically noted, the measurement wavelength is 550 nm.

[0065] In addition, in visible light, light in a wavelength region of 420 to 490 nm is blue (B) light, light in a wavelength region of 495 to 570 nm is green (G) light, and light in a wavelength region of 620 to 750 nm is red (R) light.

[0066] In the present specification, "non-visible light" refers to light in a wavelength region of less than 380 nm or a wavelength region of more than 780 nm.

[0067] In the present specification, a cholesteric liquid crystal phase is a phase having a periodic structure in which liquid crystal compounds are oriented in a helical shape, and a twist angle is 360° or more. Also, in a case where liquid crystal compounds are twisted and oriented in other optically anisotropic layers other than the cholesteric liquid crystal phase, the twist angle thereof is preferably more than 0° and less than 360°.

[0068] In the present specification, regarding terms relating to angles such as "an angle represented by a specific numerical value", "parallel", "horizontal", "vertical", and "orthogonal", unless otherwise specifically stated, an error range generally allowed in the corresponding technical field is included. Specifically, it is represented in a range of ±10° or less from a strict angle. An error from the strict angle is preferably ±7° or less, and more preferably ±5° or less.

[0069] In the present specification, regarding terms such as "the same" and "an entire surface", unless otherwise specifically stated, an error range generally allowed in the corresponding technical field is included.

[0070] In the present specification, "visible light ray transmittance" is set to A light source visible light ray transmittance prescribed in JIS (Japanese Industrial Standards) R3212:2015 (Test methods for safety glazing for buildings). That is, a transmittance is obtained by measuring a transmittance at each wavelength in a range of wavelengths of 380 to 780 nm using an A light source by a spectrophotometer, multiplying a weight value coefficient obtained from a wavelength distribution and a wavelength interval of a photopic standard match of CIE (Commission Internationale de l'Eclairage) by the transmittance at each wavelength, and performing a weighted average.

[0071] When abbreviated as "reflected light" or "transmitted light", it is used in a meaning including scattered light and diffracted light.

[0072] In the present specification, "P-polarized light" represents polarized light vibrating in a direction parallel to an incident plane of light, and "S-polarized light" represents polarized light vibrating in a direction orthogonal to the incident plane of light. Also, the "incident plane" refers to a plane perpendicular to a reflection plane (a windshield surface or the like) and containing an incident light ray and a reflected light ray. In addition, with respect to P-polarized light, a vibration plane of an electric field vector is parallel to the incident plane, and with respect to S-polarized light, the vibration plane of the electric field vector is orthogonal to the incident plane.

[0073] In the present specification, the in-plane retardation (in-plane phase difference) is a value measured using an AxoScan manufactured by Axometrics, Inc. When not particularly specified, the measurement wavelength is set to 550 nm. In addition, with respect to the in-plane retardation, a value measured by causing light of a wavelength in the visible light wavelength region to be incident in the direction of the normal line of the film is used.

[0074] In the present specification, a "projection image" indicates an image based on the projection of light from a projector used, rather than an image based on the scenery of the surroundings such as the front. The projection image is visually recognized by an observer as a virtual image that appears to be seen from the front end of the windshield when observed from the observer.

[0075] In the present specification, a "screen image" indicates an image displayed on a drawing device of a projector or an image drawn on an intermediate image screen or the like by the drawing device. The screen image is a real image in contrast to the projection image which is a virtual image. In addition, the screen image and the projection image can each be a monochromatic image, can be a multicolor image of two or more colors, or can be a full-color image.

[0076] In the present specification, "1st and 2nd" in the 1st glass plate and the 2nd glass plate do not have a technical meaning, and are provided for the purpose of distinguishing between the two glass plates. In the following description, in the case where the laminated glass is used as a windshield for a vehicle, the 1st glass plate is described as the vehicle exterior side, and the 2nd glass plate is described as the vehicle interior side.

[0077] Also, in the present specification, the "solid content" of a composition refers to components that form a cholesteric liquid crystal layer formed using the composition, and in the case where the composition contains a solvent (an organic solvent, water, or the like), refers to all components except the solvent. Also, as long as the component forms a cholesteric liquid crystal layer, a component in a liquid state is also regarded as a solid content.

[0078] [Method for manufacturing cholesteric liquid crystal layer]

[0079] The method for manufacturing a cholesteric liquid crystal layer of the present application (hereinafter, referred to as "the manufacturing method of the present application") includes:

[0080] Step 1, forming a composition layer containing a liquid crystal compound having a polymerizable group (hereinafter, also referred to as "a polymerizable liquid crystal compound"), a 1st polymerizable chiral agent (hereinafter, abbreviated as "1st polymerizable chiral agent") that changes in helical twisting power by light irradiation, and a 2nd polymerizable chiral agent (hereinafter, abbreviated as "2nd polymerizable chiral agent") having a chirality in the opposite direction to the above 1st polymerizable chiral agent;

[0081] Step 2, aligning the above liquid crystal compound in the above composition layer;

[0082] Step 3, irradiating light of a wavelength capable of changing the helical twisting power of the above-mentioned first polymerizable chiral reagent under conditions where the oxygen concentration is 1% by volume or more; and

[0083] Step 4, performing a curing treatment on the above-mentioned composition layer to fix the orientation state of the above-mentioned liquid crystal compound, thereby forming a cholesteric liquid crystal layer having a plurality of regions with different helical pitches in the thickness direction,

[0084] Between the above-mentioned Step 3 and the above-mentioned Step 4, there is Step 5 in which a heating treatment is performed on the above-mentioned composition layer, or in the above-mentioned Step 3, a heating treatment is further performed on the above-mentioned composition layer at the time of light irradiation.

[0085] The cholesteric liquid crystal layer obtained by the production method of the present application is less likely to undergo a change in the reflection spectrum when a heating treatment is performed in a state where the cholesteric liquid crystal layer is disposed on the surface of an adjacent layer. Hereinafter, the characteristic points of the production method of the present application and the presumed mechanism of action will be described.

[0086] First, as one of the characteristic points of the production method of the present application, it can be cited that a prescribed procedure is performed.

[0087] As described in detail later, in the present application, first, the polymerizable liquid crystal compound in the composition layer is oriented (Step 2). Also, in Step 2, typically, a cholesteric liquid crystal layer can be formed.

[0088] In Step 3, the oxygen concentration is low in a part of the region on the substrate (support member of the composition layer) side of the composition layer, and the oxygen concentration is high in the other region on the surface side of the side opposite to the substrate side. Therefore, in such a composition layer, if light of a wavelength capable of changing the helical twisting power of the first polymerizable chiral reagent is irradiated, in the region where the oxygen concentration is high, although the change in the helical twisting power of the first polymerizable chiral reagent (for example, photoisomerization or photodimerization, etc.) proceeds, the polymerization of the polymerizable liquid crystal compound, the first polymerizable chiral reagent, and the second polymerizable chiral reagent is difficult to proceed due to oxygen inhibition, in contrast to which, in the region where the oxygen concentration is low, the polymerization reaction of the polymerizable components such as the polymerizable liquid crystal compound, the first polymerizable chiral reagent, and the second polymerizable chiral reagent is more likely to proceed. Also, in the region where the oxygen concentration is low, although the change in the helical twisting power of the first polymerizable chiral reagent (for example, photoisomerization or photodimerization, etc.) proceeds, the speed of the above-mentioned polymerization reaction is faster, as a result of which the orientation state of the liquid crystal compound is fixed before the change in the orientation state of the liquid crystal compound caused by the change in the helical twisting power of the first polymerizable chiral reagent occurs.

[0089] Then, by the curing treatment of Step 4, the immobilization of the liquid crystal compound in the region where the oxygen concentration is high and the polymerization reaction is difficult to proceed in Step 3 is performed. As a result, the cholesteric liquid crystal layer having a plurality of regions different in helical pitch in the thickness direction is manufactured.

[0090] Further, as another feature of the production method of the present application, it can be mentioned that the chiral agent has a polymerizable group.

[0091] The present inventors and others have conjectured through this research that when a neighboring layer is disposed on the surface of the cholesteric liquid crystal layer formed using a chiral agent that does not have a polymerizable group and a heating treatment is performed, the chiral agent that is not immobilized in the cholesteric liquid crystal layer moves to the neighboring layer where the chiral agent concentration is lower, and as a result, the helical pitch decreases due to the decrease in the volume of the cholesteric liquid crystal layer, and thus a change in the reflection spectrum can occur.

[0092] In the production method of the cholesteric liquid crystal layer of the present application, a polymerizable chiral agent such as the first polymerizable chiral agent and the second polymerizable chiral agent is used to be immobilized in the cholesteric liquid crystal layer, and thus even in the case where a neighboring layer is disposed on the surface of the cholesteric liquid crystal layer and a heating treatment is performed, a change in the reflection spectrum is less likely to occur.

[0093] Hereinafter, the case where a change in the reflection spectrum is less likely to occur when a heating treatment is performed in the state where a neighboring layer is disposed on the surface of the cholesteric liquid crystal layer is sometimes referred to as the effect of the present application being more excellent.

[0094] Hereinafter, each step of the production method of the present application will be described.

[0095] [Step 1]

[0096] Step 1 is a step of forming a composition layer containing a polymerizable liquid crystal compound, a first polymerizable chiral agent, and a second polymerizable chiral agent. By performing this step, a composition layer that is subjected to the light irradiation treatment described later is formed.

[0097] Hereinafter, first, the materials used in this step will be described in detail, and then the steps of the step will be described in detail.

[0098] <Chiral agent>

[0099] (First polymerizable chiral agent)

[0100] The composition layer of Step 1 contains the first polymerizable chiral agent. The first polymerizable chiral agent is a chiral agent that has a polymerizable group and in which the helical twisting power changes by light irradiation.

[0101] Hereinafter, the first polymerizable chiral agent will be described in detail.

[0102] In addition, the helical twisting power (HTP) of the chiral agent is a coefficient indicating the helical orientation ability, and is represented by the following formula (A).

[0103] Formula (A) HTP = 1 / (length of helical pitch (unit: pm) x concentration of chiral agent with respect to liquid crystal compound (mass%)) [pm -1 ]

[0104] The length of the helical pitch refers to the length of the pitch P (= period of helix) of the helical structure of the cholesteric liquid crystal phase, and can be measured using the method described in page 196 of "Liquid Crystal Handbook" (published by MARUZEN GROUP).

[0105] There is no particular limitation on the type of the polymerizable group possessed by the first polymerizable chiral agent, but it is preferably a functional group capable of undergoing an addition polymerization reaction, more preferably a polymerizable ethylenically unsaturated group or a cyclic polymerizable group, and further preferably a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group.

[0106] There is no particular limitation on the number of the polymerizable group possessed by the first polymerizable chiral agent, but it is preferably, for example, 1 to 6, more preferably 2 to 4, and further preferably 2.

[0107] The first polymerizable chiral agent can be liquid crystalline or non-liquid crystalline. The first polymerizable chiral agent is often composed of an asymmetric carbon atom. In addition, the first polymerizable chiral agent can be an axial chiral compound or a planar chiral compound that does not contain an asymmetric carbon atom.

[0108] The first polymerizable chiral agent can be a chiral agent whose helical twisting power increases by light irradiation, or a chiral agent whose helical twisting power decreases. Among them, a chiral agent whose helical twisting power decreases by light irradiation is preferred.

[0109] In addition, in the present specification, "increase and decrease in helical twisting power" indicates the increase and decrease when the helical direction of the first polymerizable chiral agent at the initial stage (before light irradiation) is set to "positive". Therefore, in the case where the helical twisting power continuously decreases by light irradiation and exceeds 0, and the helical direction becomes "negative" (i.e., in the case where a helix whose helical direction is opposite to that at the initial stage (before light irradiation) is induced), it also corresponds to a "chiral agent whose helical twisting power decreases".

[0110] As the first polymerizable chiral agent, a so-called photo-reactive chiral agent can be mentioned. The photo-reactive chiral agent refers to a compound having a chiral site and a photo-reactive site whose structure changes by light irradiation, and, for example, greatly changes the twisting power of the liquid crystal compound depending on the amount of irradiation.

[0111] As an example of a photo-reactive site which undergoes a structural change by light irradiation, a photochromic compound (Uchida, S., Irie, M., Kagaku Kogyo, vol. 64, 640p, 1999, Uchida, S., Irie, M., Shikizai, vol. 28(9), 15p, 1999) and the like can be given. Also, the above-mentioned structural change refers to decomposition, addition reaction, isomerization, racemization, [2+2] photocyclization, dimerization reaction and the like which are caused by irradiation of light to the photo-reactive site, and the above-mentioned structural change can be irreversible. Also, as a chiral site, for example, an asymmetric carbon described in Noma, H., Kagaku Zokan, No. 22, Chemistry of Liquid Crystals, 73p: 1994 and the like can be given.

[0112] As the first polymeric chiral reagent, a compound having at least a photo-isomerization site is preferable, and the photo-isomerization site more preferably has a double bond which can be photo-isomerized. As the above-mentioned photo-isomerization site having a double bond which can be photo-isomerized, from the viewpoint of easy occurrence of photo-isomerization and large difference in helical twisting power before and after light irradiation and the like, a cinnamoyl site, a chalcone site, an azobenzene site or a stilbene site is preferable, and from the viewpoint of small absorption of visible light and the like, a cinnamoyl site, a chalcone site or a stilbene site is more preferable. In addition, the photo-isomerization site corresponds to the above-mentioned photo-reactive site which undergoes a structural change by light irradiation.

[0113] Also, from the viewpoint of high helical twisting power at the initial (before light irradiation) and more excellent change amount of helical twisting power based on light irradiation, the first polymeric chiral reagent preferably has a trans double bond which can be photo-isomerized.

[0114] Also, from the viewpoint of low helical twisting power at the initial (before light irradiation) and more excellent change amount of helical twisting power based on light irradiation, the first polymeric chiral reagent preferably has a cis double bond which can be photo-isomerized.

[0115] The first polymeric chiral reagent preferably has any one of a binaphthalene partial structure, an isosorbide partial structure (a partial structure derived from isosorbide) and an isomannide partial structure (a partial structure derived from isomannide). In addition, the binaphthalene partial structure, the isosorbide partial structure and the isomannide partial structure respectively refer to the following structures.

[0116] The part in which the solid line and the dotted line are parallel in the binaphthalene partial structure indicates a single bond or a double bond. In addition, in the structures shown below, * indicates a bonding position.

[0117] [Chemical Formula 1]

[0118]

[0119] As the first polymeric chiral reagent, a compound represented by formula (CA) is preferable.

[0120] Formula (CA) P 1 -sp 1 - (A 1 -Z 1 ) m -L 1 - (Z 2 -A 2 ) n -sp 2 -P 2

[0121] L 1 represents a divalent linking group formed by removing two hydrogen atoms from the structure represented by Formula (D) (a divalent linking group formed by removing two hydrogen atoms from the above-mentioned binaphthyl moiety structure), a divalent linking group represented by Formula (E) (a divalent linking group composed of the above-mentioned isosorbide moiety structure), or a divalent linking group represented by Formula (F) (a divalent linking group composed of the above-mentioned isomannide moiety structure).

[0122] Z 1 and Z 2 represent a single bond or a divalent linking group.

[0123] As the divalent linking group represented by Z 1 and Z 2 , preferably represents -0-, -S-, -CHRCHR-, -OCHR-, -CO-, -SO-, -S02-, -COO-, -CO-S-, -0-CO-O-, -CO-NR-, -SCHR-, -SO-CHR-, -S02-CHR-, -CF20-, -CF2S-, -OCHRCHRO-, -SCHRCHRS-, -SO-CHRCHR-SO-, -S02-CHRCHR-S02-, -CR=CR-CO-, -CR=CR-COO-, -CR=CR-OCO-, -CR=CR-CONR-, -CR=CR-COS-, -COO-CHRCHR-, -OCO-CHRCHR-, -COO-CHR-, -OCO-CHR-, -CR=CR-, -CR=N-, -N=CR-, -N=N-, -CR=N-N=CR-, -CF=CF-, or -C=C-. R represents a hydrogen atom, a cyano group, or an alkyl group having 1 to 10 carbon atoms. In addition, in the formula, in the case where a plurality of R is present, the plurality of R can be the same as or different from each other.

[0124] In the formula, Z 1 is present in a plurality of cases, the plurality of Z 1 may be the same as or different from each other. Also, in the formula, Z 2In the case of multiple Z, multiple Z 2 They can be the same as each other, or they can be different.

[0125] Furthermore, there are multiple Z. 1 and the existence of multiple Z 2 At least one preferred group is selected from the group consisting of divalent linking groups composed of -CR=CR-CO-, -CR=CR-COO-, -CR=CR-OCO-, -CR=CR-CONR-, -CR=CR-COS-, -CR=CR-, -N=N-, and -CF=CF-, and multiple Z- groups exist. 1 At least one and multiple Z in 2 At least one more preferably represents a divalent linker selected from the group consisting of -CR=CR-CO-, -CR=CR-COO-, -CR=CR-OCO-, -CR=CR-CONR-, -CR=CR-COS-, -CR=CR-, -N=N- and -CF=CF-.

[0126] A 1 and A 2 Each can be independently represented as a divalent aromatic cyclic group that may have substituents or a divalent alicyclic group that may have substituents.

[0127] As a result of A 1 and A 2 Examples of divalent aromatic cyclic groups include divalent aromatic hydrocarbon cyclic groups and divalent aromatic heterocyclic groups.

[0128] The aromatic hydrocarbon ring constituting the divalent aromatic hydrocarbon ring group can be either a monocyclic or polycyclic aromatic ring. Furthermore, the number of carbon atoms in the aromatic hydrocarbon ring is preferably 6 to 20, more preferably 6 to 10. Specific examples of the aromatic hydrocarbon ring are preferably benzene rings or naphthalene rings, more preferably benzene rings.

[0129] The number of ring elements in the aromatic heterocycle constituting the divalent aromatic heterocyclic group is preferably 5 to 10, more preferably 5 or 6. Examples of heteroatoms contained in the aromatic heterocycle include nitrogen, oxygen, and sulfur atoms. Furthermore, the number of carbon atoms in the aromatic heterocycle is preferably 3 to 20, more preferably 3 to 10. Specific examples of aromatic heterocycles include pyridine rings, pyridazine rings, pyrimidine rings, pyrazine rings, triazine rings, thiophene rings, thiazole rings, and imidazole rings.

[0130] As a result of A 1 and A 2 The divalent aromatic cyclic group is preferably a divalent aromatic hydrocarbon cyclic group, more preferably a divalent benzene cyclic group or a divalent naphthyl cyclic group.

[0131] As a result of A 1 and A2 Examples of divalent alicyclic groups include divalent aliphatic hydrocarbon cyclic groups and divalent aliphatic heterocyclic groups.

[0132] The aliphatic hydrocarbon ring that constitutes the divalent aliphatic hydrocarbon cyclic group can be either a monocyclic or polycyclic ring.

[0133] The number of ring elements in the aliphatic hydrocarbon ring is preferably 3 to 20, more preferably 3 to 10, and even more preferably 5 or 6. Specific examples of aliphatic hydrocarbon rings include cyclopentane rings, cyclohexane rings, cycloheptane rings, cyclooctane rings, norbornene rings, and adamantane rings. Among these, cyclopentane rings or cyclohexane rings are preferred.

[0134] The aliphatic heterocycle constituting the divalent aliphatic heterocyclic group can be either a monocyclic or polycyclic aliphatic ring.

[0135] Examples of heteroatoms contained in aliphatic heterocycles include nitrogen, oxygen, and sulfur atoms. The number of ring elements in an aliphatic heterocycle is not particularly limited, but is preferably 5 to 10. Specific examples of aliphatic heterocycles include oxocyclic pentane rings, oxane rings, piperidine rings, and piperazine rings. Furthermore, aliphatic heterocycles can be rings in which the -CH2- group is substituted with -CO-, for example, phthalimide rings.

[0136] As A 1 and A 2 There are no particular restrictions on the substituents that can be present; for example, alkyl groups can be mentioned.

[0137] sp 1 and sp 2 Each can independently represent at least one -CH2- that can be converted by -O-, -CO-, or -NR. X - or -S-substituted alkylene groups having 1 to 12 carbon atoms. R X It represents a hydrogen atom or an alkyl group (preferably an alkyl group with 1 to 6 carbon atoms).

[0138] As sp 1 and sp 2 Preferably, at least one -CH2- can be -O-, -CO-, or -NR. X Alkylenes having 1 to 8 carbon atoms substituted with - or -S-, more preferably indicating that at least one -CH2- can be replaced by -O-, -CO-, or -NR. X - or -S-substituted alkylene groups with 1 to 6 carbon atoms.

[0139] m and n each independently represent an integer from 1 to 10, more preferably from 1 to 8, even more preferably from 1 to 6, and especially preferably from 2 to 6.

[0140] In formula (CA), P 1 and P2 Examples include hydrogen atoms or monovalent substituents. Among them, P... 1 and P 2 At least one of them represents a polymerizable group, preferably both of them. Furthermore, the polymerizable groups mentioned above can be cited as examples of polymerizable groups.

[0141] Among them, in the formula (CA) - (A 1 -Z 1 )m- represents the structural part and is composed of -(Z 2 -A 2 At least one of the structural regions represented by n- contains a cinnamic yl region selected from (specifically, a region selected from -A). 1 -CR = CR-CO- or -A 2 -CR=CR-CO- indicates the site), chalcone site (specifically, by -A 1 -CR=CR-CO-A 1 -or-A 2 -CR=CR-CO-A 2 - indicates the region), the azobenzene region (specifically, represented by -A 1 -N=NA 1 -or-A 2 -N=NA 2 - indicates the location) and the crisscross location (specifically, represented by -A). 1 -CR=CR-A 1 -or-A 2 -CR=CR-A 2 At least one site from the group consisting of the -indicated site. As a structural site containing a cinnamicyl site, it can be a -cinnamicyl site -O- (specifically, composed of -A). 1 -CR=CR-CO-O- or -A 2 -CR=CR-CO-O- indicates the location.

[0142] Furthermore, in equation (CA), when m is an integer greater than 2, there exist multiple Z. 1 Each other and multiple A 1 They can be the same or different. Furthermore, when n is an integer greater than 2, there exist multiple Z. 2 Each other and multiple A 2 They can be the same or different.

[0143] In equations (E) and (F), * indicates the bonding position.

[0144] [Chemical Formula 2]

[0145]

[0146] as the 1st polymerizable chiral reagent,For example, there can be mentioned the photo-reactive chiral reagent described in paragraphs 0044 to 0047 of Japanese Patent Application Publication No. 2001-159709, the optically active compound described in paragraphs 0019 to 0043 of Japanese Patent Application Publication No. 2002-179669, the optically active compound described in paragraphs 0020 to 0044 of Japanese Patent Application Publication No. 2002-179633, the optically active compound described in paragraphs 0016 to 0040 of Japanese Patent Application Publication No. 2002-179670, the optically active compound described in paragraphs 0017 to 0050 of Japanese Patent Application Publication No. 2002-179668, the optically active compound described in paragraphs 0018 to 0044 of Japanese Patent Application Publication No. 2002-180051, the optically active isosorbide derivative described in paragraphs 0016 to 0055 of Japanese Patent Application Publication No. 2002-338575, the photo-reactive optically active compound described in paragraphs 0023 to 0032 of Japanese Patent Application Publication No. 2002-080478, the photo-reactive chiral reagent described in paragraphs 0019 to 0029 of Japanese Patent Application Publication No. 2002-080851, the optically active compound described in paragraphs 0022 to 0049 of Japanese Patent Application Publication No. 2002-179681, the optically active compound described in paragraphs 0015 to 0044 of Japanese Patent Application Publication No. 2002-302487, the optically active polyester described in paragraphs 0015 to 0050 of Japanese Patent Application Publication No. 2002-338668, the binaphthyl derivative described in paragraphs 0019 to 0041 of Japanese Patent Application Publication No. 2003-055315, the optically active Fulgide compound described in paragraphs 0008 to 0043 of Japanese Patent Application Publication No. 2003-073381, the optically active isosorbide derivative described in paragraphs 0015 to 0057 of Japanese Patent Application Publication No. 2003-306490, the optically active isosorbide derivative described in paragraphs 0015 to 0041 of Japanese Patent Application Publication No. 2003-306491, the optically active isosorbide derivative described in paragraphs 0015 to 0049 of Japanese Patent Application Publication No. 2003-313187, the optically active isomannide derivative described in paragraphs 0015 to 0057 of Japanese Patent Application Publication No. 2003-313188, the optically active isosorbide derivative described in paragraphs 0015 to 0049 of Japanese Patent Application Publication No. 2003-313189, the optically active polyester / amide described in paragraphs 0015 to 0052 of Japanese Patent Application Publication No. 2003-313292, the optically active compound described in paragraphs 0012 to 0053 of WO 2018 / 194157, and the optically active compound having a polymerizable group described in paragraphs 0020 to 0049 of Japanese Patent Application Publication No. 2002-179682.

[0147] (2nd polymerizable chiral agent)

[0148] The composition layer of Step 1 contains a 2nd polymerizable chiral agent.

[0149] The 2nd polymerizable chiral agent is a chiral agent that induces a helix in the opposite direction to the helix induced by the above-mentioned 1st polymerizable chiral agent (i.e., the 2nd polymerizable chiral agent is a chiral agent having a hand in the opposite direction to the hand of the above-mentioned 1st polymerizable chiral agent). For example, in the case where the helix induced by the 1st polymerizable chiral agent is in the right direction, the helix induced by the 2nd polymerizable chiral agent is in the left direction.

[0150] The 2nd polymerizable chiral agent is not particularly limited as long as it is a chiral agent having a polymerizable group and having a hand in the opposite direction to the hand of the 1st polymerizable chiral agent, and is preferably a chiral agent whose helical twisting power does not change by light irradiation.

[0151] As the kind of the polymerizable group possessed by the 2nd polymerizable chiral agent, the same group as the polymerizable group possessed by the 2nd polymerizable chiral agent can be mentioned.

[0152] The number of the polymerizable group possessed by the 2nd polymerizable chiral agent is not particularly limited, but for example, it is preferably 1 to 6, more preferably 2 to 4, and further preferably 2.

[0153] The 2nd polymerizable chiral agent can be liquid crystalline or non-liquid crystalline. The 2nd polymerizable chiral agent is often more frequently composed of an asymmetric carbon atom. In addition, the 2nd polymerizable chiral agent can be an axial chiral compound or a planar chiral compound not containing an asymmetric carbon atom.

[0154] As the 2nd polymerizable chiral agent, a publicly known chiral agent can be used.

[0155] As the 2nd polymerizable chiral agent, a compound represented by formula (CB) is preferable.

[0156] Formula (CB) P 3 -sp 3 -(A 3 -Z 3 ) p -L 2 -(Z 4 -A 4 ) q -sp 4 -P 4

[0157] In formula (CB), L 2 is the same as L 1have the same meanings and preferred modes are the same.

[0158] In formula (CB), A 3 and A 4 have the same meanings and preferred modes are the same. 1

[0159] In formula (CB), sp 3 and sp 4 have the same meanings and preferred modes are the same. 1

[0160] In formula (CB), P 3 and P 4 have the same meanings and preferred modes are the same. At least one of P 1 and P 4 represents a polymerizable group, and preferably both represent a polymerizable group. In addition, as the polymerizable group, the above-described polymerizable groups can be mentioned. 3

[0161] In formula (CB), p and q have the same meanings and preferred modes as m in formula (CA).

[0162] In formula (CB), Z 3 and Z 4 have the same meanings as Z 1 in formula (CA).

[0163] As the divalent linking group represented by Z 3 and Z 4 , -O-, -S-, -CHRCHR-, -OCHR-, -CO-, -SO-, -SO2-, -COO-, -CO-S-, -O-CO-O-, -CO-NR-, -SCHR-, -SO-CHR-, -SO2-CHR-, -CF2O-, -CF2S-, -OCHRCHRO-, -SCHRCHRS-, -SO-CHRCHR-SO-, -SO2-CHRCHR-SO2-, -COO-CHRCHR-, -OCO-CHRCHR-, -COO-CHR-, or -OCO-CHR-, are preferred.

[0164] R represents a hydrogen atom, a cyano group, or an alkyl group having 1 to 10 carbon atoms. In the formula, in the case where a plurality of R's are present, the plurality of R's can be the same as or different from each other.

[0165] In the formula, in the case where a plurality of Z 3 are present, the plurality of Z 3 ​​​The same or different from each other. Also, in the formula, Z 4 In the case where a plurality of Z 4 The same or different from each other.

[0166] The molar absorption coefficient of the first and second polymeric chiral reagents is not particularly limited, but the molar absorption coefficient at the wavelength (e.g., 365 nm) of the light to be irradiated in the later-described process 3 is preferably 100 to 100,000 L / (mol·cm), more preferably 500 to 50,000 L / (mol·cm).

[0167] The pitch of the helix of the liquid crystal compound in the cholesteric liquid crystal layer greatly depends on the kind of the first and second polymeric chiral reagents and the added concentration thereof, and thus the orientation state of the liquid crystal compound can be controlled by adjusting these.

[0168] In process 1, the total content of the first and second polymeric chiral reagents in the composition layer is not particularly limited, but from the viewpoint of easily controlling the orientation state of the liquid crystal compound, it is preferably more than 5.0% by mass, more preferably 5.5% by mass or more, and further preferably 6.0% by mass or more, relative to the total mass of the liquid crystal compound. The upper limit is not particularly limited, but it is preferably 25% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less.

[0169] The content of the first polymeric chiral reagent is not particularly limited, but from the viewpoint of easily controlling the orientation state of the liquid crystal compound, it is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, and further preferably 15 to 50% by mass, relative to the total content of the first and second polymeric chiral reagents.

[0170] The content of the first polymeric chiral reagent in the composition layer is not particularly limited, but it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.0% by mass or more, relative to the total mass of the composition layer. The upper limit is not particularly limited, but it is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3.5% by mass or less.

[0171] The content of the second polymeric chiral reagent in the composition layer is not particularly limited, but it is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and further preferably 4.0% by mass or more, relative to the total mass of the composition layer. The upper limit is not particularly limited, but it is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 6.0% by mass or less.

[0172] < Liquid Crystal Compound >

[0173] The composition layer of Step 1 contains a liquid crystal compound having a polymerizable group (a polymerizable liquid crystal compound).

[0174] The polymerizable liquid crystal compound can be a rod-like liquid crystal compound or a discotic liquid crystal compound, but is preferably a rod-like liquid crystal compound.

[0175] As the rod-like liquid crystal compound, a rod-like nematic liquid crystal compound can be mentioned. As the rod-like nematic liquid crystal compound, an azomethine compound, an azoxyl compound, a cyanobiphenyl compound, a cyanophenyl ester compound, a benzoate compound, a cyclohexanecarboxylic acid phenyl ester compound, a cyanophenylcyclohexane compound, a cyano-substituted phenylpyrimidine compound, an alkoxy-substituted phenylpyrimidine compound, a phenyldioxane compound, a tolane compound or an alkenylcyclohexylbenzonitrile compound is preferred.

[0176] Not only a low-molecular liquid crystal compound but also a high-molecular liquid crystal compound can be used.

[0177] The polymerizable liquid crystal compound is obtained by introducing a polymerizable group into a liquid crystal compound.

[0178] The kind of the polymerizable group possessed by the polymerizable liquid crystal compound is not particularly limited, and a functional group capable of undergoing an addition polymerization reaction is preferred, and a polymerizable ethylenic unsaturated group or a ring polymerizable group is more preferred, and an unsaturated polymerizable group (for example, a (meth)acryloyl group, a vinyl group, a styryl group and an allyl group, etc.), an epoxy group and an aziridine group can be mentioned, and an unsaturated polymerizable group is preferred, and an ethylenic unsaturated polymerizable group is more preferred. The polymerizable group can be introduced into the molecule of the liquid crystal compound by various methods.

[0179] The number of the polymerizable group possessed by the polymerizable liquid crystal compound is preferably 1 to 6, and more preferably 1 to 3, in one molecule.

[0180] As the polymerizable liquid crystal compound, the compounds described in Makromol. Chem., Vol. 190, p. 2255 (1989), Advanced Materials, Vol. 5, p. 107 (1993), U.S. Patent No. 4683327, U.S. Patent No. 5622648, U.S. Patent No. 5770107, International Publication No. 95 / 022586, International Publication No. 95 / 024455, International Publication No. 97 / 00600, International Publication No. 98 / 23580, International Publication No. 98 / 52905, Japanese Patent Laid-Open No. 1-272551, Japanese Patent Laid-Open No. 6-016616, Japanese Patent Laid-Open No. 7-110469, Japanese Patent Laid-Open No. 11-080081, Japanese Patent Laid-Open No. 2001-328973 and the like can be mentioned.

[0181] In the composition, two or more polymerizable liquid crystal compounds can be used in combination.

[0182] The content of the polymerizable liquid crystal compound in the composition layer is not particularly limited, but from the viewpoint of easily controlling the alignment state of the liquid crystal compound, it is preferably 60% by mass or more, more preferably 70% by mass or more, relative to the total mass of the composition layer. The upper limit is not particularly limited, but it is preferably 99% by mass or less, more preferably 97% by mass or less, further preferably 95% by mass or less, and particularly preferably 90% by mass or less.

[0183] <Other components>

[0184] The composition layer can contain other components in addition to the first polymerizable chiral agent, the second polymerizable chiral agent, and the polymerizable liquid crystal compound.

[0185] For example, the composition layer can contain a polymerization initiator. In the case where the composition layer contains a polymerization initiator, the polymerization of the liquid crystal compound having a polymerizable group is more effectively performed.

[0186] As the polymerization initiator, known polymerization initiators can be used, and photopolymerization initiators and thermal polymerization initiators can be used, and photopolymerization initiators are preferred.

[0187] The content of the polymerization initiator in the composition layer is not particularly limited, but it is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, relative to the total mass of the composition layer.

[0188] The composition layer can contain a surfactant. As the surfactant, known compounds can be used, and hydrocarbon-based surfactants, fluorine-based surfactants, and silicone-based surfactants can be used. From the viewpoint of improving environmental adaptability, it is preferred that the surfactant does not contain a fluorine atom. As the surfactant, a hydrocarbon-based surfactant or a silicone-based surfactant is preferred. As the fluorine-based surfactant, for example, the compounds described in paragraphs 0028 to 0056 of Japanese Patent Application Publication No. 2001-330725 and the compounds described in paragraphs 0069 to 0126 of Japanese Patent Application Publication No. 2003-295212 can be used.

[0189] The surfactant can be used alone or in combination with two or more kinds.

[0190] In the case where the composition layer contains a surfactant, the content of the surfactant is preferably 0.01 to 5.0% by mass, more preferably 0.01 to 3.0% by mass, and further preferably 0.05 to 1.0% by mass, relative to the total mass of the composition layer.

[0191] In order to make the liquid crystalline compound into a horizontal alignment state or a vertical alignment state, the composition layer can contain an additive that promotes horizontal alignment or vertical alignment (an alignment control agent).

[0192] As examples of the alignment control agent, there are fluorine (methyl) acrylate-based polymers described in

[0018] to

[0043] of Japanese Patent Application Publication No. 2007-272185, compounds represented by formulae (I) to (IV) described in

[0031] to

[0034] of Japanese Patent Application Publication No. 2012-203237, and compounds described in Japanese Patent Application Publication No. 2013-113913.

[0193] In addition, as the alignment control agent, one kind alone can be used, or two or more kinds can be used in combination.

[0194] There is no particular limitation on the content of the alignment control agent in the composition layer, but it is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.02 to 1% by mass, relative to the total mass of the liquid crystalline compound.

[0195] The composition layer can contain other components other than those described above. As the other components, there are polymerizable monomers, adhesion improvers, crosslinking agents, polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, pigments, and metal oxide fine particles.

[0196] <Substrate>

[0197] When the composition layer is formed, it is preferable to form the composition layer on a substrate.

[0198] The substrate is a plate that supports the composition layer.

[0199] As the substrate, a transparent substrate is preferable. In addition, the transparent substrate refers to a substrate having a transmittance of visible light of 60% or more, and the transmittance is preferably 80% or more, and more preferably 90% or more.

[0200] There is no particular limitation on the retardation value in the thickness direction of the substrate at a wavelength of 550 nm (Rth(550)), but it is preferably -110 to 110 nm, and more preferably -80 to 80 nm.

[0201] There is no particular limitation on the retardation value in the plane of the substrate at a wavelength of 550 nm (Re(550)), but it is preferably 0 to 50 nm, more preferably 0 to 30 nm, and further preferably 0 to 10 nm.

[0202] As the material that forms the substrate, a polymer having excellent optical properties, transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy is preferable.

[0203] As the polymer film that can be used as the substrate, for example, cellulose acylate film (e.g., triacetyl cellulose film (refractive index 1.48), diacetyl cellulose film, cellulose acetate butyrate film, cellulose acetate propionate film), polyolefin film such as polyethylene and polypropylene, polyester film such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone film, polymethyl methacrylate film, polyurethane film, polycarbonate film, polysulfone film, polyether film, polymethyl pentene film, polyether ketone film, (meth)acrylonitrile film, and film of a polymer having alicyclic structure (norbornene-based resin (ARTON: product name, manufactured by JSR Corporation., amorphous polyolefin (ZEONEX: product name, manufactured by Zeon Corporation)) can be exemplified.

[0204] Among them, as the material of the polymer film, triacetyl cellulose, polyethylene terephthalate, or a polymer having alicyclic structure is preferable, and triacetyl cellulose is more preferable.

[0205] Various additives (e.g., optical anisotropy adjusting agent, wavelength dispersion adjusting agent, fine particles, plasticizer, ultraviolet inhibitor, deterioration inhibitor, and peeling agent) can be contained in the substrate.

[0206] The thickness of the substrate is not particularly limited, but is preferably 10 to 200 μm, more preferably 10 to 100 μm, and further preferably 20 to 90 μm. Further, the substrate can be laminated from a plurality of sheets. In order to improve the adhesion of the substrate to the layer provided thereon, surface treatment (e.g., glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment) can be performed on the surface of the substrate.

[0207] Further, an adhesive layer (primer layer) can be provided on the substrate.

[0208] Further, in order to impart slidability in the conveying process to the substrate, or to prevent the attachment of the back surface to the surface after winding, a polymer layer in which inorganic particles having an average particle diameter of about 10 to 100 nm are mixed at a solid content mass ratio of 5 to 40 mass% can be provided on one side of the substrate.

[0209] The substrate can also be a so-called pre-support. That is, after the manufacturing method of the present application is performed, the substrate can be peeled from the cholesteric liquid crystal layer.

[0210] Further, the surface of the substrate can be directly subjected to rubbing treatment. That is, a substrate that has been subjected to rubbing treatment can be used. The direction of the rubbing treatment is not particularly limited, and the optimal direction is appropriately selected depending on the direction in which the liquid crystal compound is to be oriented.

[0211] The rubbing treatment is a widely used treatment method that can be applied as a liquid crystal alignment treatment process for LCDs (liquid crystal displays). That is, a method of rubbing the surface of a substrate in a certain direction using paper, gauze, felt, rubber, nylon fibers, polyester fibers, or the like to obtain alignment can be used.

[0212] An alignment film can be provided on the substrate.

[0213] The alignment film can be formed using rubbing treatment of an organic compound (preferably a polymer), oblique evaporation of an inorganic compound, formation of a layer having microgrooves, or a method of accumulation of an organic compound (e.g., omega-tricosanoic acid, dioctadecylmethylammonium chloride, and methyl stearate) based on the Langmuir-Blodgett method (LB film).

[0214] Furthermore, an alignment film that generates an alignment function by imparting an electric field, imparting a magnetic field, or light irradiation (preferably polarized light) is also known.

[0215] The alignment film is preferably formed by rubbing treatment of a polymer.

[0216] As the polymer included in the alignment film, for example, a methacrylate copolymer, a styrene copolymer, a polyolefin, a polyvinyl alcohol and a modified polyvinyl alcohol, a poly(N-methylol acrylamide), a polyester, a polyimide, a vinyl acetate copolymer, carboxymethyl cellulose, and a polycarbonate described in paragraph 0022 of Japanese Patent Application Publication No. 8-338913 can be mentioned. Furthermore, a silane coupling agent can be used as the polymer.

[0217] Among these, a water-soluble polymer (e.g., a poly(N-methylol acrylamide), carboxymethyl cellulose, gelatin, a polyvinyl alcohol and a modified polyvinyl alcohol, or the like) is preferable, gelatin, or a polyvinyl alcohol or a modified polyvinyl alcohol is more preferable, and a polyvinyl alcohol or a modified polyvinyl alcohol is further preferable.

[0218] As described above, the alignment film can be formed by coating a solution including the above-described polymer as an alignment film formation material and an arbitrary additive (e.g., a crosslinking agent) on a substrate, followed by heat drying (crosslinking) and rubbing treatment.

[0219] <Step of Process 1>

[0220] In the process 1, a composition layer containing the above-described components is formed, but the step thereof is not particularly limited. For example, a method in which a composition containing the above-described first polymeric chiral agent, second polymeric chiral agent, and polymeric liquid crystal compound is coated on a substrate, and a drying treatment is performed as necessary (hereinafter, also referred to simply as "coating method") and a method in which a composition layer is formed separately and transferred onto a substrate can be given. Among them, from the viewpoint of productivity, the coating method is preferred.

[0221] Hereinafter, the coating method will be described in detail.

[0222] In the composition used in the coating method, the above-described first polymeric chiral agent, second polymeric chiral agent, polymeric liquid crystal compound, and other components (for example, a polymerization initiator, etc.) used as necessary are contained.

[0223] The content of each component in the composition is preferably adjusted to be the content of each component in the above-described composition layer.

[0224] In the case of being the coating method, the composition can contain a solvent.

[0225] The solvent preferably can dissolve each component of the composition, and for example, methyl ethyl ketone, cyclohexanone (Anon), and a mixed solvent of these, etc. can be given.

[0226] In the case where the composition contains a solvent, the content of the solvent in the composition is preferably an amount in which the solid content concentration of the composition is set to 5 to 50% by mass, and more preferably an amount in which it is set to 10 to 40% by mass.

[0227] The composition can use one kind of solvent alone, or two or more kinds of solvents can be used. In the case of using two or more kinds, the total content thereof is preferably within the above-described range.

[0228] The coating method is not particularly limited, and for example, a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method can be given.

[0229] In addition, as necessary, after the composition is coated, a treatment in which a coating film coated on a substrate is dried can be performed. By performing the drying treatment, the solvent can be removed from the coating film.

[0230] The film thickness of the coating film is not particularly limited, but is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, and further preferably 0.5 to 10 μm.

[0231] 〔Process 2〕

[0232] The process 2 is a process in which the liquid crystal compound in the composition layer is oriented. By performing this process, the liquid crystal compound in the composition layer becomes an oriented state of a cholesteric liquid crystal phase. That is, as shown in FIG. 2, the liquid crystal compound in the composition layer is oriented in the direction of the arrow of the cholesteric liquid crystal phase.Figure 1 As shown, by the process 2, the composition layer 12 in which the liquid crystal compound LC is oriented in a cholesteric liquid crystal is formed on the substrate 10. Further, Figure 1 is a schematic view of a cross section of the substrate 10 and the composition layer 12.

[0233] In the process 2, it is preferable to perform a heating treatment on the composition layer to orient the liquid crystal compound in the composition layer.

[0234] As the conditions of the heating treatment, the optimum conditions are selected depending on the liquid crystal compound used.

[0235] Among them, the case where the heating temperature is 25 to 250°C is more common, the case where it is 40 to 150°C is more common, and the case where it is 50 to 130°C is further more common.

[0236] As the heating time, the case where it is 0.1 to 60 minutes is more common, and the case where it is 0.2 to 5 minutes is more common.

[0237] The orientation state of the liquid crystal compound obtained by the process 2 varies depending on the helical twisting power and the concentration of the first polymeric chiral agent and the second polymeric chiral agent.

[0238] The absolute value of the weighted average helical twisting power of the chiral agent in the composition layer formed by the process 1 is preferably 10.0 μm -1 or more, and more preferably 15.0 μm -1 or more, and further more preferably 20.0 μm -1 or more. There is no particular limitation on the upper limit, but 250 μm -1 or more is more common, and 200 μm -1 or more is more common, and 100 μm -1 or more is further more common.

[0239] Further, in the case where the absolute value of the weighted average helical twisting power of the chiral agent in the composition layer is within the above range, by the process 2, the liquid crystal compound in the composition can be oriented in a cholesteric liquid crystal.

[0240] Here, the weighted average helical twisting power of the chiral agent represents, in the case where two or more kinds of chiral agents are contained in the composition, the sum of the values obtained by dividing the product of the helical twisting power of each chiral agent contained in the composition layer and the concentration (mass%) of each chiral agent in the composition layer by the total concentration (mass%) of the chiral agents in the composition layer. For example, in the case where two kinds of chiral agents (chiral agent X and chiral agent Y) are used in combination, it is represented by the following formula (B).

[0241] Formula (B) Weighted average helical twisting power (μm -1 ) = (Helical twisting power of chiral agent X (μm -1) x concentration (mass%) of chiral agent X in the composition layer + helical twisting power (μm -1 ) of chiral agent Y in the composition layer) / (concentration (mass%) of chiral agent X in the composition layer + concentration (mass%) of chiral agent Y in the composition layer)

[0242] In the above formula (B), in the case where the helical direction of the chiral agent is right-handed, the helical twisting power is set to a positive value. Also, in the case where the helical direction of the chiral agent is left-handed, the helical twisting power is set to a negative value. That is, for example, in the case of a chiral agent having a helical twisting power of 10 μm -1 , in the case where the helical direction of the helix induced by the above chiral agent is right-handed, the helical twisting power is expressed as 10 μm -1 . On the other hand, in the case where the helical direction of the helix induced by the above chiral agent is left-handed, the helical twisting power is expressed as -10 μm -1 .

[0243] [Step 3]

[0244] Step 3 is a step of irradiating the composition layer with light of a wavelength capable of changing the helical twisting power of the first polymerizable chiral agent under conditions of an oxygen concentration of 1 vol% or more after Step 2.

[0245] Hereinafter, the mechanism of this step will be described using the drawings.

[0246] As shown in FIG. 3, Figure 1 in Step 3, light irradiation is performed from the side of the substrate 10 opposite to the side of the composition layer 12 (the direction of the hollow arrow in FIG. 3) under conditions of an oxygen concentration of 1 vol% or more. Also, in FIG. 3, light irradiation is performed from the side of the substrate 10, but it can also be performed from the side of the composition layer 12. Figure 1 Figure 1

[0247] ​​At this time, if the lower side region 12A on the substrate 10 side of the composition layer 12 and the upper side region 12B on the side opposite to the substrate 10 side are compared, the surface of the upper side region 12B is on the air side, and thus the oxygen concentration in the upper side region 12B is high, and the oxygen concentration in the lower side region 12A is low. Therefore, if light is irradiated to the composition layer 12, polymerization of the liquid crystal compound is easily performed in the lower side region 12A, and the orientation state of the liquid crystal compound is fixed. In addition, the first polymerizable chiral agent is also present in the lower side region 12A, and the helical twisting power of the first polymerizable chiral agent changes due to the light. However, in the lower side region 12A, since the orientation state of the liquid crystal compound is fixed, even if the heat treatment by the light irradiation of the following process 3 or the process 5 in which the heat treatment is performed on the composition layer to which the light irradiation of the process 3 is performed is performed, the change in the orientation state of the liquid crystal compound does not occur.

[0248] In addition, since the oxygen concentration in the upper side region 12B is high, even if the light irradiation is performed, the polymerization of the liquid crystal compound is inhibited by the oxygen and is difficult to be performed. Then, since the first polymerizable chiral agent is also present in the upper side region 12B, the helical twisting power of the first polymerizable chiral agent changes due to the light. Therefore, if the heat treatment by the light irradiation of the following process 3 or the process 5 in which the heat treatment is performed on the composition layer to which the light irradiation of the process 3 is performed is performed, the orientation state of the liquid crystal compound changes along the changed helical twisting power.

[0249] That is, by performing the light irradiation of the process 3, the fixation of the orientation state of the liquid crystal compound is easily performed in the region on the substrate side (lower side region) of the composition layer. In addition, in the region on the side opposite to the substrate side (upper side region) of the composition layer, the fixation of the orientation state of the liquid crystal compound is difficult to be performed, and becomes a state in which the helical twisting power changes depending on the first polymerizable chiral agent which is photosensitive.

[0250] The light irradiation of the process 3 is performed under the condition that the oxygen concentration is 1% by volume or more. Among them, from the viewpoint of easily forming regions in which the orientation state of the liquid crystal compound is different in the cholesteric liquid crystal layer, the oxygen concentration is preferably 2% by volume or more, and more preferably 5% by volume or more. There is no particular limitation on the upper limit, but 100% by volume can be given.

[0251] The time of the light irradiation in the process 3 is preferably 50 seconds or less, more preferably 30 seconds or less, and further preferably 10 seconds or less. There is no particular limitation on the lower limit, but from the viewpoint of the curing of the liquid crystal compound, it is preferably 0.1 second or more, and more preferably 0.2 second or more.

[0252] The light irradiation amount in the process 3 is preferably 300 mJ / cm 2 More preferably, it is 250 mJ / cm 2Further preferably, 200 mJ / cm2 2 The lower limit is not particularly limited, but from the viewpoint of curing of the liquid crystal compound, 1 mJ / cm2 2 More preferably, 5 mJ / cm2 2 The above.

[0253] In addition, in the case where the process 5 is performed after the light irradiation of the process 3, the light irradiation in the process 3 is preferably performed at 15 to 70°C (preferably, 25 to 50°C).

[0254] On the other hand, in the case where the heating treatment is performed at the time of the light irradiation of the process 3, the temperature at which the un-fixed liquid crystal compound in the composition layer is oriented is more often 40 to 250°C, more often 50 to 150°C, further more often more than 50°C and 150°C or less, and particularly often 60 to 130°C. Also, in the case where the heating treatment is performed at the time of the light irradiation of the process 3, the heating time is more often 0.01 to 60 minutes, and more often 0.03 to 5 minutes.

[0255] The light for the light irradiation is not particularly limited as long as it is light that is photosensitive to the first polymerizable chiral agent. That is, the light for the light irradiation is not particularly limited as long as it is active light or radiation that changes the helical twisting power of the first polymerizable chiral agent, and examples thereof include the bright line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, extreme ultraviolet rays, X-rays, ultraviolet rays, and electron beams. Among these, ultraviolet rays are preferred.

[0256] Also, the heating treatment can be performed at the time of the light irradiation of the process 3. The heating treatment accompanying the light irradiation of the process 3 will be described together with the process 5 in the latter stage.

[0257] 〔Process 5〕

[0258] The process 5 is a process of performing a heating treatment on the composition layer between the process 3 and the process 4. In the case where the heating treatment is performed at the time of the light irradiation of the process 3, the process 5 can not be performed.

[0259] The manufacturing method of the present application preferably has the process 5 from the viewpoint of easy formation of a prescribed cholesteric liquid crystal layer.

[0260] The process 5 is preferably a process of performing a heating treatment at a higher temperature than at the time of the light irradiation of the process 3 from the viewpoint of easy formation of a prescribed cholesteric liquid crystal layer.

[0261] By implementing step 5, the orientation state of the liquid crystal compound changes in the region where the helical torsion force of the first polymerizable chiral reagent in the composition layer after light irradiation in step 3 changes. More specifically, step 5 is a step of performing a heat treatment (preferably a heat treatment at a higher temperature than that during light irradiation in step 3) on the composition layer after light irradiation in step 3 to orient the liquid crystal compound in the composition layer that was not fixed during light irradiation in step 3.

[0262] The mechanism of this process will be described below using the accompanying drawings.

[0263] As mentioned above, if for Figure 1 When the composition layer 12 shown is irradiated with light in step 3, the orientation state of the liquid crystal compound is fixed in the lower region 12A. In contrast, polymerization of the liquid crystal compound is difficult to occur in the upper region 12B, and the orientation state of the liquid crystal compound is not fixed. Furthermore, in the upper region 12B, the weighted average helical torsional force of the first polymerizable chiral reagent changes due to the change in the helical torsion force of the first polymerizable chiral reagent and the second polymerizable chiral reagent. If such a change in the helical torsion force of the first polymerizable chiral reagent occurs, compared with the state before light irradiation in step 3, the force that twists the liquid crystal compound in the upper region 12B changes.

[0264] The following is a detailed description of the change in weighted average helical torsion force before light irradiation in step 3. Furthermore, in the following explanation, the following case will be used as an example: the composition layer 12 contains a first polymerizable chiral reagent with an induced left-handed helical direction and a helical torsion force that decreases upon light irradiation, and a second polymerizable chiral reagent with an induced right-handed helical direction and a helical torsion force that does not change upon light irradiation. The helical torsion force (μm) of the first polymerizable chiral reagent... -1 The absolute value of "concentration (mass%) of the first polymerizable chiral reagent" is less than the helical torsional force (μm) of the second polymerizable chiral reagent. -1 The absolute value of "() × concentration (mass%) of the second polymeric chiral reagent".

[0265] Figure 2 The diagram shows the helical torsional forces (μm) plotted for the first and second polymerizable chiral reagents. -1 ) × concentration (mass%) and light irradiation (mJ / cm²) 2 A diagram illustrating the relationship between ( ). Furthermore, Figure 3 The figure shows the weighted average helical torsional force (μm) of the first and second polymerizable chiral reagents. -1 ) and light irradiance (mJ / cm 2 A diagram illustrating the relationship between .

[0266] In Figure 2 and Figure 3 , the vertical axis represents "helical twisting power (μm -1 ) of the chiral agent x concentration (mass %) of the chiral agent", and the farther the value is from zero, the greater the helical twisting power. First, the relationship between the first polymerizable chiral agent and the second polymerizable chiral agent in the composition layer of Step 2 (i.e., the composition layer before light irradiation in Step 3) corresponds to the time when the amount of light irradiation is 0.

[0267] As shown in Figure 2 and Figure 3 , the weighted average helical twisting power at the time when the amount of light irradiation is 0 is greater than 0, and thus, in the composition layer 12 in which the liquid crystal compound LC formed in Step 2 is oriented in a cholesteric liquid crystal, the helical structure of the cholesteric liquid crystal phase becomes a right-handed helical structure originating from the second polymerizable chiral agent.

[0268] In the upper region 12B in this state, light irradiation is performed, and as shown in Figure 2 and Figure 3 , in the case where the helical twisting power of the first polymerizable chiral agent decreases by the amount of light irradiation, Figure 1 the weighted average helical twisting power of the chiral agent in the upper region 12B becomes greater, and the helical twisting power of the right-handed helix becomes stronger. That is, regarding the helical twisting power of the helix of the induced liquid crystal compound, the greater the amount of irradiation, the greater the helical twisting power in the direction (+) of the helix induced by the second polymerizable chiral agent.

[0269] Therefore, if the composition layer 12 after the light irradiation of Step 3 in which the weighted average helical twisting power changes is subjected to the heating treatment of Step 5 to promote the reorientation of the liquid crystal compound, as shown in Figure 4 , in the upper region 12B, the liquid crystal compound LC is more strongly twisted and oriented along the helical axis extending in the thickness direction of the composition layer 12. On the other hand, as described above, in the lower region 12A of the composition layer 12, the polymerization of the liquid crystal compound is performed at the time of light irradiation in Step 3, and the orientation state of the liquid crystal compound is fixed, and thus, the reorientation of the liquid crystal compound does not occur.

[0270] As described above, by performing Step 5, a plurality of regions having different helical pitches are formed in the thickness direction of the composition layer.

[0271] In addition, in the above Figures 2 to 4 , a method in which a chiral agent whose helical twisting power decreases by light irradiation is used as the first polymerizable chiral agent is described, but is not limited to this method. For example, a chiral agent whose helical twisting power increases by light irradiation can be used as the first polymerizable chiral agent. At this time, for example, as shown in Figure 5As shown, the weighted average helical twisting power of the cholesteric liquid crystal layer is reduced by the light irradiation of Step 3.

[0272] The heating treatment of Step 5 is preferably performed at a higher temperature than the light irradiation of Step 3.

[0273] The difference between the temperature of the heating treatment of Step 5 and the temperature at the time of the light irradiation of Step 3 is preferably 5°C or more, more preferably 10 to 110°C, and even more preferably 20 to 110°C.

[0274] The temperature of the heating treatment of Step 5 is preferably higher than the temperature at the time of the light irradiation of Step 3 and is a temperature at which the liquid crystal compound not fixed in the composition layer is oriented, and more specifically, the temperature is often 40 to 250°C, more often 50 to 150°C, even more often more than 50°C and 150°C or less, and particularly often 60 to 130°C.

[0275] The heating time of Step 5 is often 0.01 to 60 minutes, and more often 0.03 to 5 minutes.

[0276] The absolute value of the difference between the weighted average helical twisting power of the chiral agent in the composition layer after the light irradiation of Step 3 and the weighted average helical twisting power before the light irradiation of Step 3 is preferably 0.05 μm -1 More preferably, the absolute value is 0.05 to 20.0 μm -1 Further preferably, the absolute value is 0.1 to 15.0 μm -1 Especially preferably, the absolute value is 1.0 to 15.0 μm -1 Most preferably, the absolute value is 5.0 to 15.0 μm -1 .

[0277] Also, instead of Step 5, a heating treatment can be performed at the time of the light irradiation of Step 3. By performing a heating treatment at the time of the light irradiation of Step 3, the same effects as those of Step 5 can be obtained.

[0278] In the case where a heating treatment is performed at the time of the light irradiation of Step 3, the heating treatment can be performed from before the light irradiation or can be performed during the light irradiation.

[0279] In the case where a heating treatment is performed at the time of the light irradiation of Step 3, the heating temperature and the heating time are as described above.

[0280] 〔Step 4〕

[0281] Step 4 is a step of performing a curing treatment on the composition layer after the heating treatment accompanying the light irradiation of Step 3 or the heating treatment of Step 5 (i.e., after the liquid crystal compound is re-oriented), fixing the orientation state of the liquid crystal compound, and forming a cholesteric liquid crystal layer having a plurality of regions different in helical pitch in the thickness direction.

[0282] In addition, the length of the helical pitch in each of the regions formed is often constant. That is, by carrying out the present procedure, a cholesteric liquid crystal layer having a plurality of regions in which the helical pitch of the cholesteric liquid crystal phase is fixed and different along the thickness direction and the helical pitch in each of the regions is constant can be formed.

[0283] The method of the curing treatment is not particularly limited, but a light curing treatment and a thermal curing treatment can be given. Among them, a light irradiation treatment is preferred, and an ultraviolet irradiation treatment is more preferred.

[0284] A light source such as an ultraviolet lamp is used in the ultraviolet irradiation. In addition, a wavelength cutoff filter can be used at the time of ultraviolet irradiation.

[0285] The amount of light (e.g., ultraviolet) irradiation is not particularly limited, but is generally preferably 100 to 800 mJ / cm 2 or the like.

[0286] The atmosphere at the time of light irradiation is not particularly limited, and the light irradiation can be carried out under air, or the light irradiation can be carried out under an inactive atmosphere. In particular, the light irradiation is preferably carried out at an oxygen concentration of less than 1% by volume.

[0287] In the case where a light curing treatment is carried out as the curing treatment of Step 4, the temperature condition at the time of light curing is not particularly limited, as long as it is a temperature at which the orientation state of the liquid crystal compound after the heating treatment accompanying the light irradiation of Step 3 or after the heating treatment of Step 5 is maintained.

[0288] The difference between the temperature of the heating treatment accompanying the light irradiation of Step 3 or the heating treatment of Step 5 and the temperature at the time of the light curing treatment of Step 4 is preferably within 100°C, and more preferably within 80°C.

[0289] In addition, it is preferred that the temperature of the heating treatment accompanying the light irradiation of Step 3 or the heating treatment of Step 5 be the same as the temperature at the time of the light curing treatment of Step 4, or that the temperature at the time of the light curing treatment of Step 4 be a lower temperature.

[0290] In the cholesteric liquid crystal layer obtained by carrying out the curing treatment, the orientation state of the liquid crystal compound is fixed.

[0291] In addition, in the present specification, as to the "fixed" state, a state in which the orientation of the liquid crystal compound is maintained is the most typical and preferred mode. This is not limited thereto, and specifically, a state in which there is no flowability in the layer in a temperature range of generally 0 to 50°C, and more stringently, -30 to 70°C, and the orientation form does not change due to an external field or an external force, and the fixed orientation form can be stably maintained, is more preferred.

[0292] In addition, in cholesterol-type liquid crystal layers, the composition in the final layer no longer needs to exhibit liquid crystal properties.

[0293] The thickness of the cholesterol-type liquid crystal layer is not particularly limited, but it is preferably 0.05 to 10 μm, more preferably 0.1 to 8.0 μm, and even more preferably 0.2 to 6.0 μm. In addition, the thickness of the cholesterol-type liquid crystal is particularly preferably 1.8 μm or less, and most preferably 1.2 μm or less.

[0294] In a cholesteric liquid crystal layer formed by the above method, which has multiple regions with different helical pitches of the cholesteric liquid crystal phase along the thickness direction, the selective reflection center wavelengths originating from the cholesteric liquid crystal phase in each region are different. For example, the cholesteric liquid crystal layer can be a cholesteric liquid crystal layer with regions fixed along the thickness direction that are fixed to reflect blue light and cholesteric liquid crystal phases that are fixed to reflect green light, or a cholesteric liquid crystal layer with regions fixed along the thickness direction that are fixed to reflect green light and cholesteric liquid crystal phases that are fixed to reflect red light.

[0295] Furthermore, in this specification, the selection of the reflection center wavelength refers to the minimum value of the transmittance in the object (part) to be targeted, denoted as T. min (%) represents the half-value transmittance expressed by the following formula: T 1 / 2 The average value of the two wavelengths (%).

[0296] The formula for calculating half-value transmittance is: T 1 / 2 =100-(100-T min )÷2

[0297] Furthermore, in visible light, light with wavelengths above 420nm and below 500nm is blue light (B light), light with wavelengths above 500nm and below 600nm is green light (G light), and light with wavelengths above 600nm and below 700nm is red light (R light).

[0298] Furthermore, in Figure 4 The present invention describes a cholesterol-type liquid crystal layer having two regions with different helical pitches, but it is not limited to the above-described manner. A cholesterol-type liquid crystal layer may also have three or more regions with different helical pitches. Examples of cholesterol-type liquid crystal layers as described above include those having regions along the thickness direction formed by fixing a cholesterol-type liquid crystal phase that reflects blue light, a region formed by fixing a cholesterol-type liquid crystal phase that reflects green light, and a region formed by fixing a cholesterol-type liquid crystal phase that reflects red light.

[0299] [Cholesterol-type liquid crystal layer]

[0300] The cholesteric liquid crystal layer of the present application is a cholesteric liquid crystal layer in which a cholesteric liquid crystal phase is fixed, and in a cholesteric liquid crystal layer having a plurality of regions in which the pitch of the cholesteric liquid crystal phase differs in the thickness direction, the selective reflection center wavelength from the cholesteric liquid crystal phase differs in each region. For example, the cholesteric liquid crystal layer can be a cholesteric liquid crystal layer having a region in which a cholesteric liquid crystal phase that reflects blue light is fixed in the thickness direction and a region in which a cholesteric liquid crystal phase that reflects green light is fixed, or a cholesteric liquid crystal layer having a region in which a cholesteric liquid crystal phase that reflects green light is fixed in the thickness direction and a region in which a cholesteric liquid crystal phase that reflects red light is fixed.

[0301] The cholesteric liquid crystal layer has a plurality of regions in which the pitch of the cholesteric liquid crystal phase differs in the thickness direction,

[0302] The cholesteric liquid crystal layer is formed using a composition containing a liquid crystal compound having a polymerizable group (polymerizable liquid crystal compound), a first polymerizable chiral agent (first polymerizable chiral agent) in which the helical twisting power changes by light irradiation, and a second polymerizable chiral agent (second polymerizable chiral agent) having a handedness opposite to that of the first polymerizable chiral agent.

[0303] The cholesteric liquid crystal layer of the present application is a cholesteric liquid crystal layer in which a cholesteric liquid crystal phase is fixed, and in a cholesteric liquid crystal layer having a plurality of regions in which the pitch of the cholesteric liquid crystal phase differs in the thickness direction, the selective reflection center wavelength from the cholesteric liquid crystal phase differs in each region. For example, the cholesteric liquid crystal layer can be a cholesteric liquid crystal layer having a region in which a cholesteric liquid crystal phase that reflects blue light is fixed in the thickness direction and a region in which a cholesteric liquid crystal phase that reflects green light is fixed, or a cholesteric liquid crystal layer having a region in which a cholesteric liquid crystal phase that reflects green light is fixed in the thickness direction and a region in which a cholesteric liquid crystal phase that reflects red light is fixed.

[0304] The thickness of the cholesteric liquid crystal layer is not particularly limited, but is preferably 0.05 to 10 μm, more preferably 0.1 to 8.0 μm, and further preferably 0.2 to 6.0 μm. In addition, the thickness of the cholesteric liquid crystal is particularly preferably 1.8 μm or less, and most preferably 1.2 μm or less.

[0305] As the composition, various components that form the composition layer of Step 1 of the production method of the present application described in the above section can be used.

[0306] The content of the first polymerizable chiral agent in the composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.0% by mass or more, relative to the total solid content of the composition. The upper limit is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3.5% by mass or less.

[0307] The content of the second polymerizable chiral agent in the composition is not particularly limited, but is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and further preferably 4.0% by mass or more, relative to the total solid content of the composition. The upper limit is not particularly limited, but is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 6.0% by mass or less.

[0308] The content of the polymerizable liquid crystal compound in the composition is not particularly limited, but is preferably 60% by mass or more, more preferably 70% by mass or more, relative to the total solid content of the composition. The upper limit is not particularly limited, but is preferably 99% by mass or less, more preferably 97% by mass or less, further preferably 95% by mass or less, and particularly preferably 90% by mass or less.

[0309] The total content of the first polymerizable chiral agent and the second polymerizable chiral agent in the composition can be appropriately set to an amount that imparts a desired selective reflection central wavelength. As a specific example of the total content of the first polymerizable chiral agent and the second polymerizable chiral agent in the composition, it is preferably more than 5.0% by mass, more preferably 5.5% by mass or more, and further preferably 6.0% by mass or more, relative to the total mass of the liquid crystal compound. The upper limit is not particularly limited, but is preferably 25% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less.

[0310] Further, the content of the first polymerizable chiral agent can be appropriately set to an amount that imparts a desired selective reflection central wavelength, for example, it is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, and further preferably 15 to 50% by mass, relative to the total content of the first polymerizable chiral agent and the second polymerizable chiral agent.

[0311] The composition can contain other components in addition to the polymerizable liquid crystal compound, the first polymerizable chiral agent, and the second polymerizable chiral agent.

[0312] As the other components, examples include a polymerization initiator, a surfactant, and an alignment control agent.

[0313] As specific examples of the polymerization initiator, the surfactant, and the alignment control agent, the same examples as those that can be contained in the composition layer of Step 1 of the production method of the present application described in the preceding paragraph can be given.

[0314] The content of the polymerization initiator in the composition is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, relative to the total solid content of the composition.

[0315] The content of the alignment control agent in the composition is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.02 to 1% by mass, relative to the total mass of the liquid crystal compound.

[0316] The composition can contain other components in addition to those described above. As the other components, examples include a polymerizable monomer, a crosslinking agent, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, and metal oxide fine particles.

[0317] The cholesteric liquid crystal layer described above can be formed by the production method of the present application described in the above section.

[0318] [Reflective film]

[0319] The reflective film of the present application has a cholesteric liquid crystal layer. As for the cholesteric liquid crystal layer, as described above.

[0320] Hereinafter, an example of an embodiment of the reflective film of the present application will be described with reference to the drawings.

[0321] However, in the case where the reflective film is assembled into a windshield to be used as a combiner of a head-up display, in order to suppress reflection on the surface of the windshield, the projected image light is preferably p-polarized light, i.e., linearly polarized light. Therefore, it is desirable that the reflective film reflect linearly polarized light. Therefore, hereinafter, an embodiment of the reflective film that reflects linearly polarized light will be described in detail.

[0322] Further, the reflective film can have a transparent support that supports the cholesteric liquid crystal layer.

[0323] [First embodiment of reflective film]

[0324] Figure 6 is a schematic view showing an example of the reflective film of the present application. Figure 6 The reflective film 20 shown in the figure has, in order, a transparent support 22, a first phase difference layer 24, a cholesteric liquid crystal layer 26, and a second phase difference layer 28. Note that the transparent support 22 is an arbitrary member in the reflective film 20, and can not be present.

[0325] [Transparent support 22]

[0326] The total light transmittance of the transparent support 22 is preferably 80% or more, and more preferably 90% or more. There is no particular limitation on the upper limit, but less than 100% can be given as an example.

[0327] The in-plane phase difference of the transparent support 22 is preferably 10 nm or less, and more preferably 5 nm or less. Further, the absolute value of the phase difference Rth in the thickness direction of the transparent support is preferably 40 nm or less, and more preferably 30 nm or less.

[0328] By having the above-described in-plane phase difference and the phase difference in the thickness direction small, the disturbance of polarized light caused by the transparent support becomes small.

[0329] The material constituting the transparent support 22 is not particularly limited, and is preferably a resin, and more preferably a cellulose acylate resin or an acrylic resin, and further preferably a cellulose acylate resin, and particularly preferably a triacetylcellulose resin or a diacetylcellulose resin.

[0330] The thickness of the transparent support 22 is not particularly limited, but is preferably 5.0 to 1000 μm, more preferably 10 to 250 μm, and further preferably 15 to 90 μm.

[0331] <First phase difference layer 24>

[0332] The first phase difference layer 24 imparts a phase difference (optical path difference) to two orthogonal polarized light components and changes the state of incident polarized light. In addition, as a preferred example of the first phase difference layer 24, a layer in which a liquid crystal compound is uniaxially oriented and fixed (an A-plate) and the like can be given.

[0333] As the first phase difference layer 24, for example, a stretched polycarbonate film, a stretched norbornene-based polymer film, a transparent film in which inorganic particles having birefringence such as strontium carbonate are oriented, a thin film obtained by obliquely evaporating an inorganic dielectric on a support, and a film in which a liquid crystal compound is uniaxially oriented (nematic orientation) and oriented and fixed can be given.

[0334] As the first phase difference layer 24, a film in which a liquid crystal compound is uniaxially oriented and oriented and fixed is preferable.

[0335] The thickness of the first phase difference layer 24 is not particularly limited, but is preferably 0.2 to 300 μm, more preferably 0.5 to 150 μm, and further preferably 1.0 to 80 μm.

[0336] In the case where the first phase difference layer 24 is a layer in which the orientation of a liquid crystal compound is fixed, the thickness of the first phase difference layer 24 is not particularly limited, but is preferably 0.2 to 10 μm, more preferably 0.5 to 5.0 μm, and further preferably 0.7 to 2.0 μm.

[0337] <Cholesteric liquid crystal layer 26>

[0338] The cholesteric liquid crystal layer 26 has a plurality of regions in which the helical pitch of the cholesteric liquid crystal phase differs in the thickness direction, and the selective reflection center wavelength derived from the cholesteric liquid crystal phase differs in each region. As the cholesteric liquid crystal layer 26, a cholesteric liquid crystal layer obtained by the production method of the present application described above can be used. As an example of each region, from the transparent support 22 side, a region having a selective reflection center wavelength in the red (R) wavelength region, a region having a selective reflection center wavelength in the green (G) wavelength region, and a region having a selective reflection center wavelength in the blue (B) wavelength region are given in order.

[0339] The cholesteric liquid crystal layer 26 reflects light of a selective reflection center wavelength corresponding to the helical pitch, and transmits light of other wavelength regions. Also, the cholesteric liquid crystal layer 26 exhibits selective reflection properties for either one of right and left circularly polarized light at a specific wavelength.

[0340] The cholesteric liquid crystal layer 26 can be a cholesteric liquid crystal layer formed by the manufacturing method of the present application described in the above section, or can be a layer in which a cholesteric liquid crystal layer formed by the manufacturing method of the present application described in the above section and another cholesteric liquid crystal layer are laminated. Specifically, on the surface of a cholesteric liquid crystal layer having a selective reflection center wavelength in the red (IR) wavelength region, a cholesteric liquid crystal layer having a region with a selective reflection center wavelength in the red (R) wavelength region, a region with a selective reflection center wavelength in the green (G) wavelength region, and a region with a selective reflection center wavelength in the blue (B) wavelength region in the thickness direction can be laminated by the manufacturing method of the present application described in the above section.

[0341] <2nd phase difference layer 28>

[0342] The 2nd phase difference layer 28 is a so-called polarization light conversion layer. The polarization light conversion layer is a layer that shows optical activity and birefringence with respect to visible light and converts the polarization state of incident light.

[0343] As the 2nd phase difference layer 28, a layer in which the helical orientation structure of a liquid crystal compound is fixed is preferable.

[0344] In particular, the 2nd phase difference layer 28 is preferably a layer in which the helical orientation structure of a liquid crystal compound is fixed, and the number of pitches x of the helical orientation structure and the film thickness y (unit: μm) of the polarization light conversion layer satisfy all of the following relationships (a) to (c).

[0345] 0.1 ≤ x ≤ 1.0... Equation (a)

[0346] 0.5 ≤ y ≤ 3.0... Equation (b)

[0347] 3000 ≤ (1560 x y) / x ≤ 50000... Equation (c)

[0348] In addition, one pitch of the helical structure of the liquid crystal compound is the amount of one helical turn of the liquid crystal compound. That is, a state in which the director (the long axis direction if it is a rod-shaped liquid crystal) of the liquid crystal compound with the helical orientation is rotated by 360° is set to one pitch.

[0349] If the 2nd phase difference layer 28 has a helical structure of a liquid crystal compound, it shows optical activity and birefringence with respect to visible light having a shorter wavelength than the reflection peak wavelength in the infrared region. Therefore, it is possible to control the polarization light in the visible region. By setting the number of pitches x of the helical orientation structure of the 2nd phase difference layer 28 and the film thickness y of the 2nd phase difference layer 28 within the above ranges, it is possible to impart a function of optically compensating the 2nd phase difference layer 28 to visible light or a function of converting linearly polarized light (P-polarized light) incident to the reflective film 20 to circularly polarized light to the visible light.

[0350] By the liquid crystal compound having a helical structure satisfying the relational expressions (a) to (c), the second phase difference layer 28 exhibits optical rotatory and birefringence properties with respect to visible light. In particular, by setting the pitch P of the helical structure of the second phase difference layer 28 to a length corresponding to the pitch P of the cholesteric liquid crystal layer having a selected reflection center wavelength in the infrared region of long wavelengths, high optical rotatory and birefringence properties are exhibited with respect to visible light of short wavelengths.

[0351] The number x of pitches of the helical structure of the second phase difference layer 28 is more preferably 0.1 to 0.8, and the film thickness y is more preferably 0.6 to 2.6 μm. Furthermore, "(1560 x y) / x" is more preferably 5000 to 13000.

[0352] Such a second phase difference layer 28 can be formed substantially similarly to a known cholesteric liquid crystal layer.

[0353] <Function of the reflective film 20>

[0354] If light is incident on the reflective film 20 from the side of the first phase difference layer 24 or the second phase difference layer 28, it is reflected by the cholesteric liquid crystal layer 26.

[0355] In addition, as a manner of assembling the reflective film 20 of Figure 6 to a windshield, the second phase difference layer 28 is sometimes disposed on the side of a second glass plate (not shown) that becomes the inside of a vehicle, and the first phase difference layer 24 is disposed on the side of a first glass plate (not shown) that becomes the outside of the vehicle.

[0356] At this time, the second phase difference layer 28 has a function of converting projected P-polarized light (linearly polarized light) into circularly polarized light that is reflected by the cholesteric liquid crystal layer of the cholesteric liquid crystal layer 26. In contrast, the first phase difference layer 24 has an optical compensation function with respect to light incident from the outside of the windshield. For example, S-polarized light incident from the outside of the windshield changes in polarization state when passing through the second phase difference layer 28, resulting in a component of P-polarized light being mixed in. Since polarized sunglasses cut S-polarized light, the component of P-polarized light is transmitted through the polarized sunglasses. Therefore, the function of polarized sunglasses that cut glare of reflected light having S-polarized light as a main component is impaired, and there is a problem of impeding driving. In contrast, by being provided in a structure having the first phase difference layer 24 and being optically compensated by the first phase difference layer 24, the adaptability of the polarized sunglasses can be improved.

[0357] In addition, as another manner of assembling the reflective film 20 of Figure 6 to a windshield, the second phase difference layer 28 is sometimes disposed on the side of a first glass plate (not shown) that becomes the outside of a vehicle, and the first phase difference layer 24 is disposed on the side of a second glass plate (not shown) that becomes the inside of the vehicle.

[0358] At this time, the first phase difference layer 24 has a function of converting the projected P-polarized light (linearly polarized light) into circularly polarized light reflected by the cholesteric liquid crystal layer of the cholesteric liquid crystal layer 26. In this regard, the second phase difference layer 28 has an optical compensation function for light incident from the outside of the windshield, and by the optical compensation by the second phase difference layer 28, the adaptability of the polarized sunglasses can be improved.

[0359] Also, in the case where the reflective film 20 of Figure 6 is assembled to the windshield, when the first phase difference layer 24 is disposed on the side of the first glass plate (not shown) which becomes the outside of the vehicle and used as an optical compensation layer, the front surface retardation of the first phase difference layer 24 at a wavelength of 550 nm is preferably 50 to 160 nm.

[0360] Also, when the direction corresponding to the direction above the surface of the second glass plate in the vertical direction when the windshield having the reflective film 20 is installed to the vehicle is set to 0°, the angle of the slow axis of the first phase difference layer 24 is preferably 10° to 50° or -50° to -10°.

[0361] Also, in the case where the first phase difference layer 24 is used for the purpose of converting linearly polarized light into circularly polarized light, the first phase difference layer 24 is preferably composed of a layer imparting λ / 4 as the front surface phase difference, and can also be composed of a layer imparting 3λ / 4 as the front surface phase difference. Also, the angle of the slow axis is only required to be disposed in a direction in which the incident linearly polarized light is changed into circularly polarized light.

[0362] In the above-described mode, the front surface phase difference of the first phase difference layer 24 at a wavelength of 550 nm is preferably 100 to 450 nm, and more preferably 120 to 200 nm or 300 to 400 nm. Also, the direction of the slow axis of the first phase difference layer 24 is preferably determined in accordance with the incident direction of the projection light for displaying the projected image when the reflective film 20 is used for the head-up display system and the handedness of the spiral of the cholesteric liquid crystal layer.

[0363] [Other Embodiments of the Reflective Film]

[0364] The reflective film can be a mode in which the A plate described as the first phase difference layer 24 is provided on both sides of the cholesteric liquid crystal layer 26, and can also be a mode in which the polarized light conversion layer described as the second phase difference layer 28 is provided on both sides of the cholesteric liquid crystal layer 26. That is, the reflective film can be a mode in which the A plate is provided on both sides of the cholesteric liquid crystal layer, and can also be a mode in which the polarized light conversion layer is provided on both sides of the cholesteric liquid crystal layer.

[0365] In the case of assembling such a reflection film to a windshield, the first phase difference layer 24 or the second phase difference layer 28 (polarized light conversion layer) disposed on the side of the second glass plate (not shown) on the inside of the vehicle is only required to be configured to have a function of converting the projected P-polarized light (linearly polarized light) into circularly polarized light that can be reflected by the cholesteric liquid crystal layer 26. On the other hand, the first phase difference layer 24 or the second phase difference layer 28 (polarized light conversion layer) disposed on the side of the first glass plate (not shown) on the outside of the vehicle is only required to be configured to have an optical compensation function for light incident from the outside of the windshield.

[0366] Also, in the reflection film 20, the cholesteric liquid crystal layer 26 having a plurality of regions with different helical pitches of the cholesteric liquid crystal phase in the thickness direction is sequentially from the transparent support 22 side a region having a selective reflection center wavelength in the wavelength region of red (R), a region having a selective reflection center wavelength in the wavelength region of green (G), and a region having a selective reflection center wavelength in the wavelength region of blue (B), but can be sequentially from the transparent support 22 side a region having a selective reflection center wavelength in the wavelength region of blue (B), a region having a selective reflection center wavelength in the wavelength region of green (G), and a region having a selective reflection center wavelength in the wavelength region of red (R).

[0367] The average value of the reflectance at an incident angle of 5° and a wavelength of 400 to 800 nm of the reflection film is preferably 25% or less, more preferably 20% or less, and further preferably 15% or less. In addition, there is no particular limitation on the lower limit value, but for example, it is 10% or more.

[0368] The average transmittance at a wavelength of 380 to 420 nm of the reflection film is preferably 40% or more, more preferably 45% or more, and further preferably 50% or more. In addition, there is no particular limitation on the upper limit value, but for example, it is 90% or less.

[0369] [Example of the laminated glass]

[0370] The laminated glass of the present application sequentially has a first glass plate, the above-described reflection film, and a second glass plate. As for the reflection film, as described above.

[0371] Hereinafter, with reference to the drawings, one example of an embodiment of the laminated glass of the present application will be described.

[0372] [First embodiment of the laminated glass]

[0373] Figure 7 is a schematic view showing one example of the laminated glass of the present application. Figure 7 The laminated glass 30 shown sequentially has a first glass plate 32, an intermediate film 34, a reflection film 20, a heat-seal layer 36, and a second glass plate 38.

[0374] In addition, in the laminated glass 30, the interlayer film 34 and the heat-sealing layer 36 are optional components, and can not be included in the laminated glass 30. Also, the laminated glass 30 can have an adhesive layer (OCA layer) instead of the heat-sealing layer 36.

[0375] In Figure 7 In this case, the first glass plate 32 is disposed with the concave side facing the second glass plate 38, and the second glass plate 38 is disposed with the convex side facing the first glass plate 32.

[0376] In the case where the laminated glass 30 is used as a windshield for a vehicle, a curved glass is generally used as the first glass plate 32 and the second glass plate 38. In this case, if the first glass plate 32 is set to the outside of the vehicle and the second glass plate 38 is set to the inside of the vehicle, the first glass plate 32 is disposed with the concave side facing the second glass plate 38, and the second glass plate 38 is disposed with the convex side facing the first glass plate 32.

[0377] <First glass plate and second glass plate>

[0378] In the glass plates such as the first glass plate 32 and the second glass plate 38, a glass plate generally used for a windshield can be used. For example, a glass plate having a visible light transmittance of 80% or less such as green glass having a high heat insulation property and having a visible light transmittance of 73% and 76% can be used.

[0379] The thickness of the first glass plate 32 and the second glass plate 38 is not particularly limited, but is preferably about 0.5 to 5.0 mm, more preferably 1.0 to 3.0 mm, and even more preferably 2.0 to 2.3 mm. The material or thickness of the first glass plate 32 and the second glass plate 38 can be the same or different.

[0380] <Interlayer film>

[0381] The interlayer film 34 is a film for preventing the glass from penetrating and scattering in the vehicle at the time of an accident, and in the example shown in FIG. 1, is a film for bonding the reflection film 20 and the first glass plate 32. Figure 7

[0382] As the interlayer film 34 (interlayer film sheet), any known interlayer film can be used. For example, a resin film containing a resin selected from the group consisting of polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer, and chlorine-containing resin can be used. The above-mentioned resin is preferably a main component of the interlayer film. The main component means a component accounting for 50% by mass or more of the interlayer film.

[0383] Of the above-mentioned resins, polyvinyl butyral or ethylene-vinyl acetate copolymer is preferred, and polyvinyl butyral is more preferred. The resin is preferably a synthetic resin.

[0384] ​The polyvinyl butyral can be obtained by acetalization of polyvinyl alcohol with butyraldehyde. The degree of acetalization of the polyvinyl butyral is preferably 40 to 85%, more preferably 60 to 75%.

[0385] The thickness of the interlayer film 34 is not particularly limited, and can be set to a thickness corresponding to the material of formation and the like, similarly to the interlayer film of a known windshield.

[0386] <Heat-sealing layer>

[0387] The heat-sealing layer 36 is not particularly limited, and is, for example, a layer composed of a coating-type adhesive. In the case of using the heat-sealing layer 36, the heat-sealing layer 36 can be formed by coating the adhesive on the interlayer film 34. Figure 7 In the example shown, the reflective film 20 is attached to the second glass plate 38 via the heat-sealing layer 36.

[0388] The type of the heat-sealing layer 36 is not particularly limited, and can be a layer composed of various coating-type adhesives known in the art, as long as the transparency required for a windshield can be ensured, and the reflective film 20 and the second glass plate 38 can be attached with the necessary attachment force. The heat-sealing layer 36 can be formed of the same material as the interlayer film 34, such as PVB.

[0389] The heat-sealing layer 36 can be formed of an adhesive.

[0390] From the viewpoint of the curing method, the adhesive can be of a hot-melt type, a thermal curing type, a light curing type, a reaction curing type, or a pressure-sensitive adhesive type that does not require curing.

[0391] In addition, in the case of the second embodiment of the laminated glass, the heat-sealing layer 36 is described, but the reflective film can be directly attached to the second glass plate 38. Figure 7

[0392] <Adhesive layer>

[0393] In the case where the laminated glass has an adhesive layer (OCA layer) instead of the heat-sealing layer 36, the adhesive layer can be formed using a high-transparency adhesive transfer tape (OCA tape). As the high-transparency adhesive transfer tape, a commercially available product for an image display device can be used, and in particular, a commercially available product for the surface of the image display portion of an image display device can be used. As examples of the commercially available product, there are adhesive sheets (PD-S1 and the like) manufactured by PANAC Co., Ltd., and adhesive sheets of the MHM series manufactured by NICHIEI KAKOH CO., LTD.

[0394] [Second embodiment of the laminated glass]

[0395] In the case of the second embodiment of the laminated glass, the heat-sealing layer 36 is described, but the reflective film can be directly attached to the second glass plate 38. Figure 7 ​The description focuses on a laminated glass comprising a first glass plate 32, an interlayer film 34, a reflective film 20, a heat-sealing layer 36, and a second glass plate 38 in sequence. However, the structure of the laminated glass is not limited to this. For example, it could also be a laminated glass comprising a first glass plate 32, a heat-sealing layer 36, a reflective film 20, an interlayer film 34, and a second glass plate 38 in sequence. In the above embodiment, the reflective film 20 is arranged, for example, from the first glass plate 32 side in the order of transparent support 22, first retardation layer 24, cholesterol-type liquid crystal layer 26, and second retardation layer 28.

[0396] [Third Embodiment of Laminated Glass]

[0397] Figure 8 This is a schematic diagram illustrating an example of the laminated glass of the present invention. Figure 8 The laminated glass 40 shown comprises, in sequence, a first glass plate 32, an interlayer 34, a second glass plate 38, a heat-sealing layer 36, and a reflective film 20.

[0398] Furthermore, in the laminated glass 40, the heat-sealing layer 36 is an arbitrary component and may not be included in the laminated glass 40. Also, the laminated glass 40 may have an adhesive layer (OCA layer) instead of the heat-sealing layer 36.

[0399] exist Figure 8 In the middle, the reflective film 20 has a second phase reversal layer 28, a cholesterol-type liquid crystal layer 26, a first phase reversal layer 24 and a transparent support 22 sequentially from the side of the first glass plate 32.

[0400] Furthermore, the components of the laminated glass 40 are the same as those of the laminated glass 30.

[0401] <Manufacturing Methods of Laminated Glass>

[0402] The method for manufacturing the laminated glass of the present invention is not particularly limited and can be manufactured according to known methods for manufacturing laminated glass.

[0403] For example, it can be manufactured by stacking the components, repeatedly subjecting them to heat treatment and pressure treatment (such as treatment using rubber rollers), and finally using an autoclave or similar pressure treatment.

[0404] Heads-up display system

[0405] The head-up display system of the present invention includes: a windshield made of the aforementioned laminated glass; and a projector that projects light onto the windshield.

[0406] Figure 9 An example of the head-up display system of the present invention is shown in the figure.

[0407] Figure 9The head-up display system 110 of the present application shown is a vehicle-mounted head-up display system, and has a head-up display system projector 112 and a windshield 114.

[0408] Figure 9 The head-up display system projector 112 exemplified has an image forming section 120, an intermediate image screen 122, a reflecting member 124, and a concave mirror 126. In the following description, the head-up display system projector 112 will also be simply referred to as "projector".

[0409] In the head-up display system 110 exemplified, the projection light projected by the projector 112 is transmitted through a transmission window 132 provided to an instrument panel 130 and projected to the windshield 114, and observed by an observer OB. Figure 9

[0410] In the head-up display system 110 exemplified, the projection light projected by the projector 112 is transmitted through a transmission window 132 provided to an instrument panel 130 and projected to the windshield 114, and observed by an observer OB. Figure 9

[0411] In the head-up display system 110 exemplified, the projection light projected by the projector 112 is transmitted through a transmission window 132 provided to an instrument panel 130 and projected to the windshield 114, and observed by an observer OB. Figure 9 In this case, the projector 112 irradiates the projection light of P-polarized light, and the windshield 114 reflects the P-polarized light.

[0412] The present application is not limited to the case where the projector irradiates the projection light of P-polarized light and the windshield reflects the P-polarized light. Figure 9 The present application is not limited to the case where the projector irradiates the projection light of P-polarized light and the windshield reflects the P-polarized light.

[0413] Hereinafter, the respective components of the head-up display system 110 will be described in detail.

[0414] [Projector]

[0415] In the projector 112, the image forming section 120 has a light source 134, a polarizing plate 136, and a light deflector 138.

[0416] The image forming section 120 is a so-called beam scanner that forms an image by scanning of a light beam.

[0417] The image forming section 120 emits a light beam modulated in accordance with a projection image from the light source 134, sets it to P-polarized light by the polarizing plate 136, and performs secondary scanning by the light deflector 138.

[0418] ​​The projector 112 performs secondary scanning of the light beam modulated according to the projection image by the light deflector 138, forms an image thereof by the intermediate image screen 122, reflects the image by the reflection member 124 and the concave mirror 126 to a prescribed optical path. As described above, the reflected light is transmitted through the transmission window 132 provided to the instrument panel 130, is projected to the windshield 114, and is observed as a virtual image by the observer OB through the windshield 114.

[0419] The kind of the light source 134 is not particularly limited, and various light sources for image formation can be used.

[0420] As an example of the light source 134, a light emitting diode (LED), a discharge tube, a laser light source, and the like are exemplified. In addition, the LED includes a light emitting diode, an organic light emitting diode (OLED), and the like.

[0421] The polarizing plate 136 sets the incident light beam to P-polarized light (P-linearly polarized light).

[0422] The kind of the polarizing plate 136 is not particularly limited, and various general linear polarizing plates (linear polarizers) can be used.

[0423] As an example of the polarizing plate 136, a polarizing plate in which thin films having different refractive index anisotropies are stacked can be given. As the polarizing plate in which thin films having different refractive index anisotropies are stacked, for example, the polarizing plate described in Japanese Laid-Open Patent Publication No. 09-506837 and the like can be used. Specifically, if processing is performed under conditions selected in order to obtain a refractive index relationship, various materials can be widely used to form the polarizing plate.

[0424] The polarizing plate in which thin films having different refractive index anisotropies are stacked can use a commercially available product. As the commercially available product, for example, DBEF (3M Company), APF (Advanced Polarizing Film), and the like can be given.

[0425] Further, as the polarizing plate 136, a general linear polarizing plate such as an absorption-type polarizing plate including an iodine compound and a reflection-type polarizing plate such as a wire grid can be used.

[0426] In addition, in the above Figure 9In this method, the polarizer 136 sets the incident light beam to P-polarized light (P-linearly polarized light), but it is not limited to this method of the present invention. The polarizer can also set the incident light beam to S-polarized light (S-linearly polarized light). In this case, the phase difference layer can convert the S-polarized light into P-polarized light. In addition, when the light becomes S-polarized light after passing through the polarizer, it is sometimes possible to reduce the amount of light lost in subsequent reflecting components.

[0427] As optical deflector 138, it is possible to utilize various conventional optical deflectors capable of scanning the beam twice.

[0428] Examples of optical deflectors 138 include Galvano mirrors (galvanometer mirrors), combinations of Galvano mirrors and multifaceted mirrors, and microelectromechanical systems (MEMS). Among these, MEMS is preferred.

[0429] In the projector 112, the image forming unit 120 forms a projected image and an image by scanning a beam of light, but the present invention is not limited thereto.

[0430] That is, in the projector of the present invention, the image forming mechanism can utilize various conventional image forming mechanisms used in projectors (imagers) of head-up display systems.

[0431] As an example of an image forming mechanism, LCD (Liquid Crystal Display) and LCOS (Liquid Crystal On Silicon) are used, which utilize fluorescent tubes or liquid crystals.

[0432] Alternatively, as another example of an image forming mechanism, an organic electroluminescent (organic EL) display may be used.

[0433] Alternatively, as another example of an image forming mechanism, DLP (Digital Light Processing) using a DMD (Digital Micro mirror Device) can be employed.

[0434] The projection light emitted from the image forming unit 120 is then visualized (realized) by the intermediate image screen 122.

[0435] There are no particular restrictions on the type of intermediate image screen 122, and known intermediate image screens can be used appropriately.

[0436] As described above, the projected light, which is realized by the intermediate image screen 122, is reflected onto a predetermined light path by the reflective component 124 and the concave mirror 126.

[0437] There are no particular restrictions on the types of reflective components 124 and concave mirrors 126; known components can be used appropriately.

[0438] in addition, Figure 9 The projector 112 illustrated uses a reflective component 124 and a concave mirror 126 as components to change the optical path of the projected light, but the present invention is not limited thereto.

[0439] That is, the projector of the present invention may not have a concave mirror, but only a reflective component as a component to change the optical path of the projected light, or it may have one or more other light reflective elements in addition to the reflective component and the concave mirror.

[0440] In addition to concave mirrors and ordinary mirrors, freeform mirrors and the like can also be used as light reflecting elements. That is, as long as the projector of the present invention has the reflecting component of the present invention, it can utilize a structure that uses various light reflecting elements.

[0441] In addition to the concave mirror mentioned above, diffraction and reflection elements can also be used as components to change the optical path of the projected light. Examples of diffraction and reflection elements include holographic diffraction gratings and surface relief diffraction gratings.

[0442] 〔windshield〕

[0443] Windshield 114 refers to ordinary window glass and windproof glass for vehicles such as automobiles and trams, airplanes, ships, two-wheeled vehicles, and amusement equipment. Windshields are preferably used as front windows and windproof glass located in front of the vehicle in the direction of travel.

[0444] The laminated glass of the present invention is used as the windshield 114.

[0445] When a windshield made of the laminated glass of the present invention is used in a vehicle, the first glass panel 32 is disposed on the outer side of the vehicle and the second glass panel 38 is disposed on the inner side of the vehicle.

[0446] There is no limitation on the visible light transmittance of the windshield 114, but a higher transmittance is preferred. The visible light transmittance of the windshield 114 is preferably 70% or more, more preferably over 70%, further preferably over 75%, and especially preferably over 80%.

[0447] Preferably, the above-mentioned visible light transmittance is satisfied at any position of the windshield 114, and it is particularly preferred that the above-mentioned visible light transmittance is satisfied at the position where the reflective film is present.

[0448] 〔use〕

[0449] The head-up display system of the present invention can be applied to a variety of purposes.

[0450] For example, in-vehicle head-up display systems can be cited.

[0451] [Composition]

[0452] The composition of the present invention comprises a liquid crystal compound having polymerizable groups, a first polymerizable chiral reagent whose helical torsional force changes upon light irradiation, and a second polymerizable chiral reagent having a helical orientation opposite to that of the first polymerizable chiral reagent.

[0453] As the above composition, various components of the composition layer formed in step 1 of the manufacturing method of the present invention described in the previous section can be used.

[0454] The content of the first polymerizable chiral reagent in the composition is not particularly limited, but it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, relative to the total solid content of the composition. There is no particular upper limit, but it is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3.5% by mass or less.

[0455] The content of the second polymerizable chiral reagent in the composition is not particularly limited, but it is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, and even more preferably 4.0% by mass or more, relative to the total solid content of the composition. There is no particular upper limit, but it is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6.0% by mass or less.

[0456] There is no particular limitation on the content of the polymerizable liquid crystal compound in the composition, but it is preferably 60% by mass or more, more preferably 70% by mass or more, relative to the total solid content of the composition. There is no particular upper limit, but it is preferably 99% by mass or less, more preferably 97% by mass or less, further preferably 95% by mass or less, and especially preferably 90% by mass or less.

[0457] The total content of the first and second polymerizable chiral reagents in the composition can be appropriately set to impart a desired selective reflection center wavelength. As a specific example of the total content of the first and second polymerizable chiral reagents in the composition, it is preferably more than 5.0% by mass, more preferably 5.5% by mass or more, and even more preferably 6.0% by mass or more, relative to the total mass of the liquid crystal compound. There is no particular upper limit, but it is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0458] Furthermore, the content of the first polymerizable chiral reagent can be appropriately set to an amount that imparts the desired selective reflection center wavelength. For example, relative to the total content of the first polymerizable chiral reagent and the second polymerizable chiral reagent, it is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, and even more preferably 15 to 50% by mass.

[0459] The composition may contain other components besides the polymerizable liquid crystal compound, the first polymerizable chiral reagent, and the second polymerizable chiral reagent.

[0460] Other components include polymerization initiators, surfactants, and orientation control agents.

[0461] Specific examples of polymerization initiators, surfactants, and orientation control agents include those that are the same as those contained in the composition layer of step 1 of the manufacturing method of the present invention described above.

[0462] The content of the polymerization initiator in the composition is not particularly limited, but it is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, relative to the total solid content of the composition.

[0463] The content of the orientation control agent in the composition is not particularly limited, but it is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and especially preferably 0.02 to 1% by mass relative to the total mass of the liquid crystal compound.

[0464] The composition may contain other components besides those mentioned above. Examples of other components include polymerizable monomers, crosslinking agents, polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles.

[0465] Example

[0466] The present invention will now be described in further detail with reference to embodiments. The materials, amounts, proportions, processing contents, and processing steps shown in the following embodiments can be appropriately modified without departing from the spirit of the invention. Therefore, the scope of the present invention should not be limited by the embodiments shown below.

[0467] [Sample Preparation]

[0468] The following shows the various coating liquids used in the fabrication of reflective films.

[0469] [Composition a for forming liquid crystal layer]

[0470] Composition a for forming liquid crystal layers was prepared by mixing the following components.

[0471] ----------------------------------

[0472] Composition of composition a for forming liquid crystal layer

[0473] ----------------------------------

[0474] • 100.0 parts by weight of the following liquid crystal compound LC1

[0475] • Photopolymerization initiator (OXE01, manufactured by BASF) 3.0 parts by weight

[0476] • 1.2 parts by weight of compound A (sealing modifier)

[0477] • 0.1 parts by weight of compound B (orientation control agent)

[0478] • The chiral reagent C1 shown in Table 1

[0479] Adjust the orientation of the target and select the amount of reflected wavelength (the following is the amount of adjustment A).

[0480] • The chiral reagent C2 shown in Table 1

[0481] Adjust the orientation of the target and select the amount of reflected wavelength (the following is the amount of adjustment A).

[0482] • Mixed solvent (methyl ethyl ketone (MEK) / cyclohexanone (mass ratio 70 / 30))

[0483] The concentration of the solid component is 20% by mass.

[0484] ----------------------------------

[0485] <Combination amount of chiral reagent C1 and chiral reagent C2 (combination amount A)>

[0486] In the liquid crystal layer forming composition a, the mixing ratio and total amount of chiral reagent C1 and chiral reagent C2 are set as the mixing ratio and total amount that make the liquid crystal layer forming composition a satisfy the following conditions.

[0487] (Furthermore, regarding the liquid crystal layer forming composition a, according to each embodiment, the types of chiral reagent C1 and chiral reagent C2 included in the composition are different, and the helical torsional force exhibited by each chiral reagent also varies depending on its type. Therefore, when using the liquid crystal layer forming composition a to form an orientation state in which the lower layer is horizontally oriented and the upper layer has a selective reflection wavelength of 901 nm through the prescribed steps shown below, according to each embodiment, the mixing ratio and total amount of chiral reagent C1 and chiral reagent C2 required to form the desired orientation state are different.)

[0488] (condition)

[0489] After forming a liquid crystal layer with a thickness of 1.3 μm using composition a, when forming a phase retardation layer (lower layer) and selective reflection layer 1 (upper layer) according to the same steps as described later (fabrication of liquid crystal layer A), the lower layer is horizontally oriented and the selective reflection wavelength of the upper layer is 901 nm.

[0490] The following shows the ingredients used.

[0491] -Liquid crystal compound LC1-

[0492] [Chemical Formula 3]

[0493]

[0494] -Compound A-

[0495] [Chemical Formula 4]

[0496]

[0497] -Compound B-

[0498] [Chemical Formula 5]

[0499]

[0500] [Composition b for forming liquid crystal layer]

[0501] Composition b for forming liquid crystal layers was prepared by mixing the following components.

[0502] ----------------------------------

[0503] Composition of composition b for forming liquid crystal layer

[0504] ----------------------------------

[0505] · 100.0 parts by weight of the above liquid crystal compound LC1

[0506] • Photopolymerization initiator (OXE01, manufactured by BASF) 4.0 parts by weight

[0507] • 0.03 parts by weight of compound B (orientation control agent) mentioned above.

[0508] • The chiral reagent C1 shown in Table 1

[0509] Adjust the orientation of the target and select the amount of reflected wavelength (the following is the matching amount B).

[0510] • The chiral reagent C2 shown in Table 1

[0511] Adjust the orientation of the target and select the amount of reflected wavelength (the following is the matching amount B).

[0512] • Mixed solvent (MEK / cyclohexanone (mass ratio 70 / 30))

[0513] The concentration of the solid component is 25% by mass.

[0514] ----------------------------------

[0515] <Combination amount of chiral reagent C1 and chiral reagent C2 (combination amount B)>

[0516] In the liquid crystal layer forming composition b, the mixing ratio and total mixing amount of chiral reagent C1 and chiral reagent C2 are set as the mixing ratio and total mixing amount that make the liquid crystal layer forming composition b satisfy the following conditions.

[0517] (Furthermore, regarding the liquid crystal layer forming composition b, according to each embodiment, the types of chiral reagents C1 and C2 included in the composition are different, and the helical torsional force exhibited by each chiral reagent also varies depending on its type. Therefore, when using the liquid crystal layer forming composition b to form an orientation state with a selective reflection wavelength of 715 nm for the lower layer and a selective reflection wavelength of 560 nm for the upper layer through the prescribed steps shown below, according to each embodiment, the mixing ratio and total amount of chiral reagents C1 and C2 required to form the desired orientation state are different.)

[0518] (condition)

[0519] After forming a liquid crystal layer with a thickness of 1.0 μm using composition b, when forming the selective reflection layer 2 (lower layer) and selective reflection layer 3 (upper layer) according to the same steps as described later (formation of liquid crystal layer B), the selective reflection wavelength of the lower layer is 715 nm and the selective reflection wavelength of the upper layer is 560 nm.

[0520] [Composition t1 for forming the second phase difference layer (A)]

[0521] The following components were mixed to prepare composition t1 for forming the second phase difference layer (A).

[0522] ----------------------------------

[0523] Composition of composition t1 for forming the second phase difference layer (A)

[0524] ----------------------------------

[0525] · 100.0 parts by weight of the above liquid crystal compound LC1

[0526] • Photopolymerization initiator (OXE01, manufactured by BASF) 1.0 part by weight

[0527] • 0.25 parts by weight of compound C (orientation control agent)

[0528] • Mixed solvent (MEK / cyclohexanone (mass ratio 85 / 15))

[0529] The concentration of the solid component is 30% by mass.

[0530] ----------------------------------

[0531] -Compound C-

[0532] The values ​​of each repeating unit in compound C are based on mole percent.

[0533] [Chemical Formula 6]

[0534]

[0535] [Composition t2 for forming the second phase difference layer (B) (polarization conversion layer)]

[0536] The following components were mixed to prepare composition t2 for forming a second phase difference layer (B).

[0537] ----------------------------------

[0538] Composition of composition t2 for forming the second phase difference layer (B)

[0539] ----------------------------------

[0540] · 100.0 parts by weight of the above liquid crystal compound LC1

[0541] • Photopolymerization initiator (OXE01, manufactured by BASF) 1.0 part by weight

[0542] • 0.25 parts by weight of compound C (orientation control agent) mentioned above.

[0543] • Chiral reagent C2 as listed in Table 1

[0544] Adjust the orientation of the target and select the amount of reflected wavelength (the following is the matching amount T).

[0545] • Mixed solvent (MEK / cyclohexanone (mass ratio 85 / 15))

[0546] The concentration of the solid component is 30% by mass.

[0547] ----------------------------------

[0548] <Combination amount of chiral reagent C2 (combination amount T)>

[0549] In the composition t2 for forming the second phase difference layer (B), the amount of chiral reagent C2 is set to the amount that satisfies the following conditions in the composition t2 for forming the second phase difference layer (B).

[0550] (condition)

[0551] After forming a second phase retardation layer (B) with a thickness of 1.6 μm using the composition t2, and then applying it to the environment at 50°C with an oxygen concentration of less than 100 ppm by volume, a metal halide lamp with a cutoff wavelength of less than 330 nm is used to achieve a flux of 300 mJ / cm². 2 If the liquid crystal phase is fixed by accumulating light, then the reflection wavelength is chosen to be 8500nm.

[0552] [Composition h for heat-sealing layer formation]

[0553] Composition h for heat-sealing layer formation was prepared by mixing the following components.

[0554] ----------------------------------

[0555] Composition of heat-sealing layer forming composition h

[0556] ----------------------------------

[0557] • Photopolymerization initiator (Omnirad 127, manufactured by IGM Resins BV) 2.0 parts by weight

[0558] • Particle dispersion (AC-1011F3) (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) 50.0 parts by weight

[0559] • Adhesive (Kurarity LA4285, manufactured by KURARAY CO., LTD.) 95.5 parts by weight

[0560] • Mixed solvent (MEK / butyl acetate (the mass ratio of butyl acetate used in the preparation of the dispersion is 50 / 50))

[0561] The concentration of the solid component is expressed as 10% by mass.

[0562] ----------------------------------

[0563] The following shows the chiral reagents C1 and C2 as shown in Table 1. Additionally, compounds 1B to 4B and compound R2 are chiral reagents whose helical torsional force changes upon irradiation with light (ultraviolet light (365 nm) described later).

[0564] -Compound 1A-

[0565] [Chemical Formula 7]

[0566]

[0567] -Compound 1B-

[0568] [Chemical Formula 8]

[0569]

[0570] -Compound 2B-

[0571] [Chemical Formula 9]

[0572]

[0573] -Compound 3B-

[0574] [Chemical Formula 10]

[0575]

[0576] -Compound 4B-

[0577] [Chemical Formula 11]

[0578]

[0579] -Compound R1-

[0580] [Chemical Formula 12]

[0581]

[0582] -Compound R2-

[0583] [Chemical Formula 13]

[0584]

[0585] [Fabrication and Evaluation of Reflective Films]

[0586] The following section explains the manufacturing method and evaluation of the reflective film.

[0587] Furthermore, in the manufacturing steps of the reflective film in each embodiment, the step of using liquid crystal layer forming composition b to manufacture liquid crystal layer B is equivalent to the manufacturing method of the present invention described in the previous section.

[0588] [Examples 1-3, Comparative Example 1]

[0589] (Fabrication of liquid crystal layer A)

[0590] Liquid crystal forming composition a was coated onto a TAC (triacetyl cellulose) film with an oriented film, to a dried film thickness of 1.3 μm. After coating, the film was left to stand at room temperature for 15 seconds, then heated at 60°C for 30 seconds. Subsequently, it was irradiated with 60 mJ / cm² at 40°C under atmospheric conditions. 2 The sample was then heated again for 30 seconds under ultraviolet light (wavelength 365 nm) at 60 °C. Afterwards, it was heated to 300 mJ / cm² under an oxygen concentration of less than 100 ppm at 50 °C using a metal halide lamp with a wavelength cutoff below 330 nm. 2 The cholesterol-type liquid crystal phase is fixed by exposure using a cumulative light intensity method, thereby forming a liquid crystal layer A on the TAC film having a phase retardation layer (first phase retardation layer) and a selective reflection layer 1. That is, using liquid crystal layer forming composition a, the phase retardation layer (first phase retardation layer) and the selective reflection layer 1 are formed together on the TAC film.

[0591] (Fabrication of liquid crystal layer B)

[0592] Next, liquid crystal layer forming composition b was coated onto the aforementioned liquid crystal layer A to achieve a dried film thickness of 1.0 μm. After coating, the mixture was left to stand at room temperature for 15 seconds, then heated at 60°C for 30 seconds. Afterward, it was irradiated with 60 mJ / cm² at 40°C under atmospheric conditions. 2The sample was then heated again for 30 seconds under ultraviolet light (wavelength 365 nm) at 60 °C. Afterwards, it was heated to 300 mJ / cm² under an oxygen concentration of less than 100 ppm at 50 °C using a metal halide lamp with a wavelength cutoff below 330 nm. 2 The cholesterol-type liquid crystal phase is fixed by exposure using a cumulative light intensity method, thereby forming a liquid crystal layer B having a selective reflection layer 2 and a selective reflection layer 3 on the liquid crystal layer A. That is, using liquid crystal layer forming composition b, the selective reflection layer 2 and the selective reflection layer 3 are formed together on the liquid crystal layer A. In other words, a cholesterol-type liquid crystal layer with multiple regions having different helical pitches along the thickness direction is formed.

[0593] (Fabrication of the second phase difference layer (A))

[0594] Next, a second phase reversal layer (A) forming composition t1 was coated onto the aforementioned liquid crystal layer B to achieve a dried film thickness of 1.6 μm. After coating, the mixture was subjected to a metal halide lamp with a cutoff wavelength of 330 nm at 50°C and an oxygen concentration of 100 ppm or less, at a speed of 300 mJ / cm². 2 The liquid crystal phase is fixed by accumulating light, thereby forming a second phase difference layer (A) on the liquid crystal layer B.

[0595] Using the reflective film (hereinafter also referred to as "reflective film T") made through the above steps, the various evaluations described in the following section were carried out.

[0596] [Examples 4-6 and Comparative Examples 2 and 3]

[0597] (Example 4)

[0598] Except for changing the types of chiral compound C1 and chiral reagent C2, liquid crystal layer B was fabricated using the same method as in Example 1. Next, a second phase retardation layer (A) forming composition t1 was coated onto the obtained liquid crystal layer B to a dried film thickness of 1.6 μm. After coating, the mixture was heated at 50°C with an oxygen concentration of 100 ppm or less, and then heated with a metal halide lamp with a cutoff wavelength of 330 nm at a concentration of 300 mJ / cm². 2 The liquid crystal phase is immobilized by exposure using a cumulative light intensity method, thereby forming a second retardation layer (A) (reflective film T) on the liquid crystal layer B. Next, a heat-sealing layer forming composition h is further coated onto the surface of the second retardation layer (A) with a dried film thickness of 0.7 μm. After coating, the mixture is sealed at room temperature in a solvent atmosphere and left to stand for 15 seconds. Then, it is heated at 120°C for 60 seconds, and then heated with a mercury lamp (without a wavelength cutoff filter) at a concentration of 300 mJ / cm² in a room temperature environment with an oxygen concentration below 100 ppm.2 The liquid crystal phase is fixed by exposure through the accumulation of light, thereby obtaining a reflective film with a heat-sealing layer (hereinafter also referred to as "reflective film H with a heat-sealing layer").

[0599] (Examples 5 and 6, and Comparative Examples 2 and 3)

[0600] On the liquid crystal layer B obtained by the respective fabrication methods of Example 3 or Comparative Example 1, a second phase retardation layer (A) forming composition t1 or a second phase retardation layer (B) forming composition t2 was coated to a dried film thickness of 1.6 μm. After coating, the mixture was subjected to a metal halide lamp with a cutoff wavelength of 330 nm at 50°C and an oxygen concentration of 100 ppm or less, at a speed of 300 mJ / cm². 2 The liquid crystal phase is immobilized by exposure using a cumulative light intensity method, thereby forming a second retardation layer (A) or a second retardation layer (B) (polarization conversion layer) (reflective film T) on the liquid crystal layer B. Next, a heat-sealing layer forming composition h is further coated onto the surface of the second retardation layer (A) or the second retardation layer (B) to a dried film thickness of 0.7 μm. After coating, the mixture is sealed at room temperature in a solvent atmosphere and left to stand for 15 seconds. Then, it is heated at 120°C for 60 seconds in a room temperature environment with an oxygen concentration of less than 100 ppm by volume, and heated with a mercury lamp (without using a wavelength cutoff filter) at a concentration of 300 mJ / cm². 2 The liquid crystal phase is fixed by accumulating light, thereby obtaining a reflective film H with a heat-sealing layer.

[0601] Using the heat-sealed reflective film H prepared through the above steps, the various evaluations described in the following section were carried out.

[0602] [Various evaluations]

[0603] <Spectroscopic determination of membranes alone>

[0604] (Reflectance spectroscopy measurement)

[0605] Using a spectrophotometer (JASCO Corporation, V-670), the reflectivity of the reflective film T obtained by the fabrication methods of Examples 1 to 6 was measured from 350 to 900 nm by incident P-polarized light and S-polarized light at a direction of 5° relative to the normal direction of the film from the second retardation layer side (the second retardation layer (A) or the second retardation layer (B) side). Furthermore, the reflectivity spectrum was obtained by averaging the obtained spectra of the P-polarized and S-polarized light.

[0606] The reflective films T obtained by the fabrication methods of Examples 1 to 6 all have an average reflectivity of less than 15% at wavelengths of 400 to 800 nm.

[0607] (Transmission spectroscopy measurement)

[0608] Furthermore, using the same spectrophotometer, P-polarized light and S-polarized light were incident from the normal direction (front 0°) of the reflective film T obtained by the fabrication methods of Examples 1 to 6, from the side of the second retardation layer (the side of the second retardation layer (A) or the side of the second retardation layer (B)), and the transmittance from 350 to 900 nm was measured. The transmittance spectrum was obtained by averaging the obtained spectra of the P-polarized light and S-polarized light.

[0609] The reflective films T obtained by the fabrication methods of Examples 1 to 6 all have an average transmittance of over 50% at wavelengths of 380 to 420 nm.

[0610] <Durability Evaluation 1 (Heat treatment at 140°C for 85 minutes)>

[0611] (Examples 1-3 and Comparative Example 1)

[0612] The second phase retardation layer (A) side of the reflective film T of Examples 1-3 and Comparative Examples was bonded to a 2 mm thick glass using an adhesive with a thickness of 10 μm. Furthermore, the support side (TAC film side) was clamped and fixed with the same 2 mm thick glass and subjected to a heat treatment (heat treatment) at 140°C for 85 minutes.

[0613] For the reflective film T attached to the glass before heating and the reflective film T attached to the glass after heating (samples in the state of having the 2 mm thick glass used for fixation removed after heating), reflectance spectra were measured according to the following steps.

[0614] (Reflectance spectroscopy measurement)

[0615] Using a spectrophotometer (JASCO Corporation, V-670), P-polarized and S-polarized light were incident from the glass side at a 5° angle relative to the glass normal, and the reflectance from 350 to 900 nm was measured. Furthermore, the reflectance spectra of the obtained P-polarized and S-polarized light were averaged to obtain the reflectance spectra.

[0616] (Determination of wavelength shift Δ in reflectance spectra before and after heating)

[0617] The positions at wavelengths of 700 nm, 550 nm, and 450 nm in the reflection spectrum of the reflective film T before heating (in addition, in the reflection spectrum of the reflective film T, the positions at wavelengths of 700 nm, 550 nm, and 450 nm typically correspond to peaks, troughs, and tails) are set as observation points (A). 700 A 550 A450 ).

[0618] Compare the reflection spectrum of the reflective film T before heating with the reflection spectrum of the reflective film T after heating, and calculate the values ​​of the reflection spectrum of the heated reflective film T that correspond to the observation points (A, B, C). 700 A 550 A 450 The corresponding wavelength (observation point A) 700 Wavelength after heating: X (nm), observation point A 550 Wavelength after heating: Y (nm), observation point A 450 The wavelength after heating: Z (nm)).

[0619] The wavelength corresponding to the above observation points refers to, for example, the wavelength at observation point A. 700 For example, if the peak position in the reflection spectrum of the reflective film T before heating is at a wavelength of 700 nm, and the peak position in the reflection spectrum of the heated reflective film T after heating is observed at a wavelength of 690 nm, then the observation point A after heating... 700 The corresponding wavelength becomes 690nm. Furthermore, while the peak position has been explained above, for example, if the wavelength of 700nm in the reflection spectrum of the reflective film T before heating corresponds to the midpoint between the peak and trough of the reflection spectrum, then the wavelength at that midpoint in the reflection spectrum of the heated reflective film T corresponds to the corresponding wavelength.

[0620] Next, the wavelength displacement S at each observation point before and after heating is calculated using the following equations (1) to (3). 700 S 550 and S 450 Next, calculate S. 700 S 550 and S 450 The arithmetic mean of the reflected spectrum (refer to formula (4)) is set as the wavelength shift Δ (nm) before and after heating.

[0621] Formula (S1)

[0622] S 700 =|(wavelength Xnm (after heating)) -(wavelength 700nm (before heating))|

[0623] Equation (S2)

[0624] S 550 =|(wavelength Ynm (after heating)) -(wavelength 550nm (before heating))|

[0625] Formula (S3)

[0626] S 450=|(wavelength Znm (after heating)) -(wavelength 450nm (before heating))|

[0627] Equation (S4) Δ=(S 700 +S 550 +S 450 ) / 3

[0628] The evaluation was conducted based on the wavelength shift Δ (nm) of the reflection spectrum before and after heating, according to the following evaluation criteria. The results are shown in Table 1.

[0629] (Evaluation Criteria)

[0630] “A”: Δ≤10nm

[0631] “B”: 10nm < Δ ≤ 15nm

[0632] “C”: 15nm < Δ

[0633] <Durability Evaluation 2 (Heat treatment for 24 hours at 90°C / 80%RH)>

[0634] (Examples 1-3 and Comparative Example 1)

[0635] The second phase difference layer (A) side of the reflective film T of Examples 1-3 and Comparative Examples was bonded to a 2 mm thick glass with an adhesive with a thickness of 10 μm, and subjected to heat treatment for 24 hours at 90°C / 80%RH.

[0636] The reflectance spectra of the reflective film T before and after heating were measured using the same method as in durability evaluation 1. Furthermore, based on the reflective film T before and after heating, the wavelength shift Δ (nm) of the reflectance spectrum before and after heating was calculated using the same method as in durability evaluation 1, and an evaluation was performed. The results are shown in Table 1.

[0637] <Durability Evaluation 3 (Heating and Vacuum Evacuation (140℃, 2 hours) → Heating and Pressurizing (140℃, 1.2MPa, 45 minutes))>

[0638] (Examples 4-6 and Comparative Examples 2 and 3)

[0639] The heat-sealing reflective film H prepared in Examples 4-6 and Comparative Examples 2 and 3 was laminated with other components in the following configuration. Furthermore, the heat-sealing reflective film H was laminated with the heat-sealing side facing the first glass side.

[0640] First glass / Reflective film H with heat-sealing layer / Intermediate film / PET film for release / Second glass

[0641] Next, the laminate was subjected to heat treatment 1 (vacuum evacuation at 140°C for 2 hours) to establish a temporary press-fit state. After that, the temporarily press-fit laminate was subjected to heat treatment 2 (at 140°C and 1.2 MPa for 45 minutes).

[0642] The reflectance spectra of the reflective film H with the heat-sealed layer were measured using the same method as in durability evaluation 1, before temporary pressing (heat treatment 1) and after heated pressing (heat treatment 2). Furthermore, when measuring the reflectance spectrum of the reflective film H with the heat-sealed layer after heated pressing, the intermediate film / peeling PET film / second glass was removed from the sample after heated pressing, and the above measurements were performed.

[0643] Furthermore, based on the reflective film H with heat-sealing layer before temporary pressing (heat treatment 1) and after heated pressing (heat treatment 2), the wavelength shift Δ (nm) of the reflectance spectrum before temporary pressing (heat treatment 1) and after heated pressing (heat treatment 2) is determined by the same method as in durability evaluation 1.

[0644] Next, based on the wavelength shift Δ (nm) of the reflection spectrum before and after heating, an evaluation was conducted according to the following evaluation criteria. The results are shown in Table 1.

[0645] (Evaluation Criteria)

[0646] “A”: Δ≤5nm

[0647] “B”: 5nm < Δ ≤ 10nm

[0648] “C”: 10nm < Δ

[0649] <Durability Evaluation 4 (Heat treatment for 24 hours at 90°C / 80%RH)>

[0650] (Examples 4-6 and Comparative Examples 2 and 3)

[0651] The reflective film H with heat-sealing layer, after the above-mentioned durability evaluation 3 was performed, was subjected to a 24-hour heat treatment (heat treatment) at an environment of 90℃ / 80%RH.

[0652] The reflectance spectra of the heat-sealed reflective film H before and after heating were measured using the same method as in durability evaluation 1. Furthermore, based on the heat-sealed reflective film H before and after heating, the wavelength shift Δ (nm) of the reflectance spectrum before and after heating was calculated using the same method as in durability evaluation 3, and an evaluation was performed. The results are shown in Table 1.

[0653] Table 1 is shown below.

[0654] In addition, the thickness of the reflective layer 1 is calculated based on the fitting analysis of the reflection spectrum of the liquid crystal layer A, and the thicknesses of the reflective layers 2 and 3 are calculated based on the fitting analysis of the transmission spectrum of the liquid crystal layer B.

[0655] Furthermore, in the liquid crystal layer forming composition b of Example 1, the content of chiral compound C1 relative to the total solid content of the composition is 3.1% by mass, the content of chiral compound C2 relative to the total solid content of the composition is 4.8% by mass, and the weighted average helical torsion force before light irradiation in step 3 is 28.6 μm. -1 The weighted average helical torsional force after light irradiation in process 3 is 36.6 μm. -1 .

[0656] Furthermore, in the liquid crystal layer forming composition b of Example 2, the content of chiral compound C1 relative to the total solid content of the composition is 2.1% by mass, the content of chiral compound C2 relative to the total solid content of the composition is 4.7% by mass, and the weighted average helical torsion force before light irradiation in step 3 is 33.5 μm. -1 The weighted average spiral torsional force after light irradiation in process 3 is 42.8 μm. -1 .

[0657] Furthermore, in the liquid crystal layer forming composition b of Example 3, the content of chiral compound C1 relative to the total solid content of the composition is 1.9% by mass, the content of chiral compound C2 relative to the total solid content of the composition is 4.8% by mass, and the weighted average helical torsion force before light irradiation in step 3 is 34.2 μm. -1 The weighted average helical torsional force after light irradiation in process 3 is 43.6 μm. -1 .

[0658] Furthermore, in the liquid crystal layer forming composition b of Example 4, the content of chiral compound C1 is 1.6% by mass relative to the total solid content of the composition, the content of chiral compound C2 is 5.5% by mass relative to the total solid content of the composition, and the weighted average helical torsion force before light irradiation in step 3 is 31.9 μm. -1 The weighted average helical torsional force after light irradiation in process 3 is 40.7 μm. -1 .

[0659] Furthermore, in the liquid crystal layer forming composition b of Examples 5 and 6, the content of chiral compound C1 relative to the total solid content of the composition is 1.9% by mass, the content of chiral compound C2 relative to the total solid content of the composition is 4.8% by mass, and the weighted average helical torsion force before light irradiation in step 3 is 34.2 μm. -1 The weighted average helical torsional force after light irradiation in process 3 is 43.6 μm. -1 .

[0660] Furthermore, the "Cure rate of selected reflective layer" column in Table 1 indicates the cure rate of liquid crystal layer B.

[0661] The curing rate was determined using the ATR (Attenuated Total Reflection) method. Specifically, the determination was performed through the following steps: When fabricating the aforementioned reflective film T and the reflective film H with a heat-sealing layer, a film extending up to the liquid crystal layer B was designated as a sample film. The sample film was placed in the ATR measuring device with the liquid crystal layer B side abutting against a prism of the measuring unit, and light was incident upon it (the depth of light penetration into the sample film: approximately 1 μm). The reflected light reflected by the sample film was measured.

[0662] [Table 1]

[0663]

[0664] The results in Table 1 clearly show that the variation in the reflectance spectrum of the reflective film in the embodiment having the cholesterol-type liquid crystal layer obtained by the manufacturing method of the present invention is decreasing.

[0665] Furthermore, based on comparisons of various embodiments, it was confirmed that when the first and second polymerizable chiral reagents each have two or more polymerizable groups, the change in the reflectance spectrum is further reduced.

[0666] [Windshield manufacturing]

[0667] Using the reflective film H with heat-sealing layer prepared in Examples 4 to 6, windshields were manufactured through the following steps, and it was confirmed that they all functioned as head-up displays.

[0668] [Windshield fabrication 1]

[0669] As the first and second glass plates, glass plates with a length of 260mm × width of 330mm and a thickness of 2mm were prepared. As the intermediate film, a PVB film with a thickness of 0.76mm (manufactured by SEKISUI CHEMICAL CO., LTD.) was prepared.

[0670] Next, the heat-sealing reflective film H, the first glass plate, the second glass plate, and the intermediate film were laminated using two configuration methods, namely (1) and (2), as shown below. In configuration method (1), the heat-sealing layer side of the heat-sealing reflective film H was arranged opposite the first glass plate, and in configuration method (2), the heat-sealing layer side of the heat-sealing reflective film H was arranged opposite the second glass plate.

[0671] Configuration method (1):

[0672] First glass panel (outer side of the vehicle) / Reflective film H with heat-sealing layer / Intermediate film / Second glass panel (inner side of the vehicle)

[0673] Configuration method (2):

[0674] First glass panel (outer side of the vehicle) / Interlayer film / Reflective film H with heat-sealing layer / Second glass panel (inner side of the vehicle)

[0675] Next, the two types of laminates were kept at 140°C and 10 kPa for 2 hours, and then heated at 135°C and 1.3 MPa for 45 minutes using an autoclave (manufactured by Kurihara Seisakusho Co., Ltd.) to remove air bubbles, thereby obtaining two types of windshields.

[0676] [Windshield Manufacturing 2]

[0677] Glass plates measuring 260mm in length and 330mm in width, with a thickness of 2mm, were prepared as the first, second, and third glass plates. Furthermore, a 0.76mm thick PVB film (manufactured by SEKISUI CHEMICAL CO., LTD.) was prepared as the mold for the support (TAC film) of the heat-sealing layer and the heat-sealing reflective film H with the intermediate film and heat-sealing layer.

[0678] Next, the heat-sealed reflective film H, the first glass plate, the second glass plate, the third glass plate, the interlayer film, the fixing PVB, and the third glass plate were laminated according to the configuration method (3) shown below. In configuration method (3), the heat-sealed reflective film H was arranged with the heat-sealed side facing the second glass plate.

[0679] Configuration method (3):

[0680] First glass panel (outer side) / Interlayer film / Second glass panel (inner side) / Reflective film H with heat-sealing layer / PVB for fixing / Third glass panel

[0681] Next, the obtained laminate was held at 140°C and 10 kPa for 2 hours, and then heated at 135°C and 1.3 MPa for 45 minutes using an autoclave (manufactured by Kurihara Seisakusho Co., Ltd.) to remove air bubbles. Then, the PVB and the third glass plate were peeled off from the support (TAC film) of the heat-sealed reflective film H, thereby obtaining a windshield in which the heat-sealed reflective film H is bonded to the outside of a laminated glass composed of the first and second glass plates.

[0682] Symbol Explanation

[0683] 10-Substrate, LC-Liquid Crystal Compound, 12-Composition Layer, 12B-Upper Region, 12A-Lower Region, 22-Transparent Support, 24-First Phase Retardation Layer, 26-Cholesterol-type Liquid Crystal Layer, 28-Second Phase Retardation Layer, 20-Reflective Film, 30, 40-Laminated Glass, 32-First Glass Plate, 34-Intermediate Film, 36-Heat-Sealing Layer, 38-Second Glass Plate, 110-Head-Up Display System, 112-Projector, 114-Windshield, 120-Image Forming Unit, 122-Intermediate Image Screen, 124-Reflective Component, 126-Concave Mirror, 130-Instrument Panel, 132-Transmission Window, 134-Light Source, 136-Polarizer, 138-Light Deflector, OB-Observer.

Claims

1. A method for manufacturing a cholesterol-type liquid crystal layer, comprising: Step 1: Forming a composition layer comprising a liquid crystal compound having polymerizable groups, a first polymerizable chiral reagent whose helical torsional force changes upon light irradiation, and a second polymerizable chiral reagent having a helical orientation opposite to that of the first polymerizable chiral reagent. Step 2, aligning the liquid crystal compound in the composition layer; Step 3: Under conditions where the oxygen concentration is 1% by volume or higher, irradiate with light of a wavelength that can change the helical torsional force of the first polymerizable chiral reagent. and Step 4 involves curing the composition layer to fix the orientation state of the liquid crystal compound, forming a cholesterol-type liquid crystal layer with multiple regions having different helical pitches along the thickness direction. Between step 3 and step 4, there is a step 5 in which the composition layer is subjected to heat treatment, or in step 3, the composition layer is further subjected to heat treatment under light irradiation.

2. The method for manufacturing a cholesterol-type liquid crystal layer according to claim 1, wherein, The first and second polymerizable chiral reagents each have two or more polymerizable groups.

3. The method for manufacturing a cholesterol-type liquid crystal layer according to claim 1 or 2, wherein, The first and second polymerizable chiral reagents comprise partial structures selected from the group consisting of isosorbide, isomannitol, and binaphthyl.

4. The method for manufacturing a cholesterol-type liquid crystal layer according to claim 1 or 2, wherein, The first polymerizable chiral reagent has photoisomerizable double bonds within the molecule.

5. The method for manufacturing a cholesterol-type liquid crystal layer according to claim 4, wherein, The first polymerizable chiral reagent comprises a photoisomerization site selected from the group consisting of cinnamyl, chalcone, and piperyl sites.

6. The method for manufacturing a cholesterol-type liquid crystal layer according to claim 1 or 2, wherein, The thickness of the cholesterol-type liquid crystal layer is less than 10 μm.

7. A cholesterol-type liquid crystal layer, wherein a cholesterol-type liquid crystal phase is fixed thereon, It has multiple regions with different helical pitches in the thickness direction. The cholesterol-type liquid crystal layer is a layer formed using a composition comprising a liquid crystal compound having polymerizable groups, a first polymerizable chiral reagent whose helical torsional force changes upon light irradiation, and a second polymerizable chiral reagent having a helical orientation opposite to that of the first polymerizable chiral reagent.

8. A reflective film having the cholesterol-type liquid crystal layer of claim 7.

9. A reflective film having, in sequence, a first retardation layer, a cholesterol-type liquid crystal layer as described in claim 7, and a second retardation layer.

10. The reflective film according to claim 9, wherein, The average reflectivity at an incident angle of 5° and a wavelength of 400–800 nm is less than 15%.

11. The reflective film according to claim 9, wherein, The average transmittance at wavelengths of 380–420 nm is over 50%.

12. A laminated glass comprising, in sequence, a first glass plate, a reflective film as claimed in claim 8, and a second glass plate.

13. The laminated glass according to claim 12, wherein, A heat-sealing layer or adhesive layer is provided between the first glass plate and the reflective film or between the second glass plate and the reflective film.

14. A laminated glass comprising, in sequence, a first glass plate, an interlayer film, a second glass plate and the reflective film of claim 8.

15. The laminated glass according to claim 14, wherein, A heat-sealing layer or adhesive layer is provided between the second glass plate and the reflective film.

16. A head-up display system comprising: a windshield made of laminated glass according to any one of claims 12 to 15; and a projector that projects projection light onto the windshield.

17. The head-up display system according to claim 16, wherein, The projector projects P-polarized light.

18. A composition comprising: a liquid crystal compound having polymerizable groups; a first polymerizable chiral agent whose helical torsional force changes upon light irradiation; and a second polymerizable chiral agent having an orientation opposite to that of the first polymerizable chiral agent.

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