Light control sheet, method for manufacturing light control sheet, and liquid crystal composition for high-molecular dispersion

Abstract

The light control sheet of the present application is a light control sheet provided with an organic polymer layer (31P) that divides a plurality of gaps (31D) and a liquid crystal composition (31LC) that contains a non-polymerizable liquid crystal compound (LCM) and fills the gaps (31D), and changes the transmittance of visible light by driving the non-polymerizable liquid crystal compound (LCM), wherein the liquid crystal composition (31LC) contains an adipate ester as a non-polymerizable viscosity reducing agent (DP), and the weight of the non-polymerizable viscosity reducing agent (DP) is 1% or more relative to the weight of the non-polymerizable liquid crystal compound (LCM), whereby the responsiveness of the transmittance to a change in potential difference can be improved.

Description

Technical Field

[0001] This disclosure relates to dimming sheets comprising nonpolymeric liquid crystal compounds, methods for manufacturing dimming sheets, and polymer-dispersed liquid crystal compositions. Background Technology

[0002] The dimming sheet comprises a first transparent electrode layer, a second transparent electrode layer, and a dimming layer sandwiched between the first and second transparent electrode layers. The orientation state of the non-polymerizable liquid crystal compound contained in the dimming layer changes the transmittance of the dimming sheet according to the change in the potential difference between the two transparent electrode layers. For example, when the orientation order of the non-polymerizable liquid crystal compound is constructed, the dimming sheet exhibits high transmittance. When the long axis direction of the non-polymerizable liquid crystal compound is disordered, the dimming sheet exhibits low transmittance (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-45135 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] On the other hand, the responsiveness of transmittance to changes in the potential difference between the two transparent electrode layers varies depending on the ambient temperature at which the dimming sheet is installed. The wider the range of ambient temperatures at which transmittance changes within a specified time before the potential difference switches, the broader the application range of the dimming sheet. In particular, in applications requiring cold environments, it is necessary to change transmittance within a specified time at low ambient temperatures. For example, when a dimming sheet is attached to a vehicle window, the ambient temperature at which the sheet is installed is significantly lower than that of items inside the vehicle. If the time required for transmittance change can be shortened in low-temperature environments, the suitability of dimming sheets for vehicle applications can be improved.

[0008] Means for solving technical problems

[0009] The dimming sheet used to solve the above-mentioned technical problems is a dimming sheet comprising an organic polymer layer with multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, wherein the transmittance of visible light is changed by driving the non-polymerizable liquid crystal compound, wherein the liquid crystal composition contains a non-polymerizable viscosity reducer as shown in formula (1). In formula (1), X is a straight-chain or branched alkyl or aryl group having 1 or more and 6 or fewer carbon atoms, and R... 1 R 2 R 3Each is independently a hydrogen atom or a functional group as shown in formula (2), r 4 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. r in formula (2) 5 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms.

[0010] [Chemical structural formula 1]

[0011]

[0012] [Chemical structural formula 2]

[0013]

[0014] The dimming sheet used to solve the above-mentioned technical problems is a dimming sheet comprising an organic polymer layer with multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, wherein the transmittance of visible light is changed by driving the non-polymerizable liquid crystal compound, wherein the liquid crystal composition contains a non-polymerizable viscosity reducer as shown in formula (3). r in formula (3) 6 r 7 r 8 Each is independently a straight-chain alkyl group having 3 or more but less than 8 carbon atoms.

[0015] [Chemical structural formula 3]

[0016]

[0017] A method for manufacturing a dimming sheet to solve the above-mentioned technical problems is to manufacture a dimming sheet having an organic polymer layer with multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, and to change the transmittance of visible light by driving the non-polymerizable liquid crystal compound. The method includes polymerizing the ultraviolet-curable compound in a layer containing the liquid crystal composition and the ultraviolet-curable compound, thereby separating the liquid crystal particles formed by the liquid crystal composition from the organic polymer layer. The liquid crystal composition contains a non-polymerizable viscosity reducer as shown in formula (1). The weight ratio of the organic polymer layer to the total weight of the organic polymer layer and the liquid crystal composition is 30% by mass or more and 60% by mass or less, and the weight ratio of the non-polymerizable viscosity reducer to the weight of the non-polymerizable liquid crystal compound is 1% by mass or more and 8% or less.

[0018] A method for manufacturing a dimming sheet to solve the above-mentioned technical problems is to manufacture a dimming sheet having an organic polymer layer with multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, and to change the transmittance of visible light by driving the non-polymerizable liquid crystal compound. The method includes polymerizing the ultraviolet-curable compound in a layer containing the liquid crystal composition and the ultraviolet-curable compound, thereby separating the liquid crystal particles formed by the liquid crystal composition from the organic polymer layer. The liquid crystal composition contains a non-polymerizable viscosity reducer as shown in formula (3). The weight of the organic polymer layer relative to the total weight of the organic polymer layer and the liquid crystal composition is 30% by mass or more and 60% by mass or less, and the weight of the non-polymerizable viscosity reducer relative to the weight of the non-polymerizable liquid crystal compound is 1% by mass or more and 8% or less.

[0019] The polymer-dispersed liquid crystal composition for solving the above-mentioned technical problems is a polymer-dispersed liquid crystal composition in which the ultraviolet-curable compound is polymerized in a layer containing a liquid crystal composition and an ultraviolet-curable compound, thereby causing phase separation from the organic polymer layer as a polymer. The liquid crystal composition contains a non-polymerizable liquid crystal compound and a non-polymerizable viscosity reducer as shown in the above formula (1). The weight ratio of the ultraviolet-curable compound to the total weight of the ultraviolet-curable compound and the liquid crystal composition is 30% by mass or more and 60% by mass or less, and the weight ratio of the non-polymerizable viscosity reducer to the weight of the non-polymerizable liquid crystal compound is 1% by mass or more and 8% or less.

[0020] The polymer-dispersed liquid crystal composition for solving the above-mentioned technical problems is a polymer-dispersed liquid crystal composition in which the ultraviolet-curable compound is polymerized in a layer containing a liquid crystal composition and an ultraviolet-curable compound, thereby causing phase separation from the organic polymer layer as a polymer. The liquid crystal composition contains a non-polymerizable liquid crystal compound and a non-polymerizable viscosity reducer as shown in the above formula (3). The weight ratio of the ultraviolet-curable compound to the total weight of the ultraviolet-curable compound and the liquid crystal composition is 30% by mass or more and 60% by mass or less, and the weight ratio of the non-polymerizable viscosity reducer to the weight of the non-polymerizable liquid crystal compound is 1% by mass or more and 8% or less.

[0021] Based on the above-described components, through the interaction of electron localization in the non-polymerizable liquid crystal compound and electron localization in the non-polymerizable viscosity reducer, the terminal alkyl groups of the non-polymerizable viscosity reducer readily exist between adjacent non-polymerizable liquid crystal compounds. The presence of alkyl groups, as non-polar groups, between the non-polymerizable liquid crystal compounds weakens the intermolecular interactions within them. This, in turn, improves the responsiveness of transmittance at low ambient temperatures, such as -20°C.

[0022] Furthermore, the liquid crystal compound filling the voids in the organic polymer layer is formed by using a photopolymerizable compound for forming the organic polymer layer and a liquid crystal composition. The liquid crystal compound undergoes phase separation from the organic polymer layer through polymerization of the photopolymerizable compound. At this time, a non-polymerizable viscosity reducer is suitable for phase separation from the organic polymer layer. Furthermore, the low molecular weight structures shown in formulas (1) to (3) above are also suitable for diffusion from the polymer of the photopolymerizable compound, i.e., phase separation from the organic polymer layer.

[0023] In the aforementioned dimming sheet, the weight ratio of the organic polymer layer to the total weight of the organic polymer layer and the liquid crystal composition can be 30% by mass or more and 60% by mass or less.

[0024] In the aforementioned dimming sheet, the weight ratio of the non-polymerizable viscosity reducer to the weight of the non-polymerizable liquid crystal compound can be 1% or more and 8% or less. This configuration also suppresses the reduction in the orientation order of the non-polymerizable liquid crystal compound at low ambient temperatures, such as -20°C. Furthermore, according to this configuration, the effectiveness of achieving the aforementioned effects is improved, and the control of transferring the non-polymerizable liquid crystal compound to a disordered phase at high ambient temperatures, such as 100°C, becomes easier.

[0025] In the above-mentioned dimming sheet, X in formula (1) is a straight-chain alkyl group with 1 or more and 6 or less carbon atoms, and R in formula (1) is a linear alkyl group. 1 It is the functional group shown in equation (2) above, in equation (1) above, R 2 R 3 Each is an independent hydrogen atom.

[0026] In the aforementioned dimming sheet, the Ni point of the non-polymeric liquid crystal compound can be above 100°C and below 145°C.

[0027] In the aforementioned dimming sheet, the non-polymerizable viscosity reducer can be any one of diisodecyl adipate, dibutyl adipate, dioctyl adipate, bis(2-butoxyethyl) adipate, and diisononyl adipate. Based on this configuration, the reduction in the orientation order of the non-polymerizable liquid crystal compound can also be suppressed at low ambient temperatures, such as -20°C.

[0028] In the aforementioned dimming sheet, the weight of all the aforementioned non-polymerizable viscosity reducers contained in the aforementioned liquid crystal composition relative to the total weight of the aforementioned non-polymerizable liquid crystal compound and the aforementioned non-polymerizable viscosity reducers can be 2% by mass or more and 6% by mass or less.

[0029] The aforementioned dimming sheet can also be configured as follows: further comprising a first transparent electrode layer and a second transparent electrode layer, wherein the aforementioned organic polymer layer is located between the transparent electrode layers, and the aforementioned liquid crystal composition consists of liquid crystal particles phase-separated from the aforementioned organic polymer layer, which change from a transparent state to an opaque state by releasing the voltage applied between the aforementioned transparent electrode layers. According to this configuration, in a forward-type dimming sheet, the responsiveness of light transmittance at low ambient temperatures, such as -20°C, can be improved.

[0030] The aforementioned dimming sheet can also be configured as follows: further comprising a first transparent electrode layer and a second transparent electrode layer, wherein the aforementioned organic polymer layer is located between the transparent electrode layers, and the aforementioned liquid crystal composition consists of liquid crystal particles separated from the aforementioned organic polymer layer phase, which are transformed from a transparent state to an opaque state by applying a voltage between the aforementioned transparent electrode layers. According to this configuration, the responsiveness of light transmittance at low ambient temperatures, such as -20°C, can be improved in the reverse-type dimming sheet.

[0031] Invention Effects

[0032] According to this disclosure, a dimming sheet capable of shortening the time required for a change in transmittance to occur in response to a change in potential difference, a method for manufacturing the dimming sheet, and a polymer-dispersed liquid crystal composition can be provided. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the configuration of a dimming device according to one embodiment.

[0034] Figure 2 This is a structural diagram showing the cross-sectional configuration of a dimming sheet according to one embodiment.

[0035] Figure 3 This table shows the composition and evaluation results of the polymer-dispersed liquid crystal compositions of each embodiment.

[0036] Figure 4 This table shows the composition and evaluation results of the polymer-dispersed liquid crystal compositions of each embodiment.

[0037] Figure 5 This table shows the composition and evaluation results of the polymer-dispersed liquid crystal compositions of each embodiment.

[0038] Figure 6This table shows the composition and evaluation results of the polymer-dispersed liquid crystal compositions of each embodiment.

[0039] Figure 7 This table shows the composition and evaluation results of the polymer-dispersed liquid crystal compositions for each comparative example. Detailed Implementation

[0040] An embodiment of a dimming sheet, a polymer-dispersed liquid crystal composition, and a method for manufacturing the dimming sheet will be described. First, referring to... Figure 1 The composition of the dimming device will be explained. Next, refer to... Figure 2 The composition of the dimming sheet and the polymer-dispersed liquid crystal composition is explained. Finally, the manufacturing method of the dimming sheet and various embodiments of the dimming sheet are described.

[0041] The dimming sheet is adhered to a transparent substrate. The transparent substrate can be glass or resin. Examples of transparent substrates include window glass on moving objects such as vehicles or airplanes, window glass installed in buildings, and partitions installed inside vehicles or interiors. The surface on which the dimming sheet is adhered can be flat or curved. The dimming sheet can also be sandwiched between two transparent substrates.

[0042] The dimming sheet can be driven in either a forward or reverse manner. In a forward-type dimming sheet, the sheet changes from opaque to transparent due to the application of voltage, and returns to opaque when the voltage is removed. In a reverse-type dimming sheet, the sheet changes from transparent to opaque due to the application of voltage, and returns to transparent when the voltage is removed.

[0043] Furthermore, both the forward and reverse types share the common feature of having two transparent electrode layers and a dimming layer. The following primarily explains the structure and function of the reverse type; for the forward type, details of the differences from the reverse type are provided; and for the forward type, details repeating the reverse type are omitted.

[0044] [Dimming Device]

[0045] like Figure 1 As shown, the dimming device 10 includes a dimming sheet 11 and a driving unit 12. The dimming sheet 11 includes a dimming layer 31, a first alignment layer 32, a second alignment layer 33, a first transparent electrode layer 34, a second transparent electrode layer 35, a first transparent support layer 36, and a second transparent support layer 37.

[0046] The dimming layer 31 is located between the first alignment layer 32 and the second alignment layer 33. The first surface 31F of the dimming layer 31 contacts the first alignment layer 32, and the second surface 31S of the dimming layer 31 contacts the second alignment layer 33. The first alignment layer 32 is located between the dimming layer 31 and the first transparent electrode layer 34 and contacts both the dimming layer 31 and the first transparent electrode layer 34. The second alignment layer 33 is located between the dimming layer 31 and the second transparent electrode layer 35 and contacts both the dimming layer 31 and the second transparent electrode layer 35.

[0047] The first transparent electrode layer 34 is connected to the drive unit 12 via the first connection terminal 22A and the first wiring 23A. The first transparent electrode layer 34 is located between the first alignment layer 32 and the first transparent support layer 36, and contacts the first alignment layer 32 and the first transparent support layer 36. The second transparent electrode layer 35 is connected to the drive unit 12 via the second connection terminal 22B and the second wiring 23B. The second transparent electrode layer 35 is located between the second alignment layer 33 and the second transparent support layer 37, and contacts the second alignment layer 33 and the second transparent support layer 37.

[0048] The dimming layer 31 has an organic polymer layer 31P (refer to...) Figure 2 ) and liquid crystal composition 31LC (refer to) Figure 2 The organic polymer layer 31P defines voids 31D that are filled by the liquid crystal composition 31LC. The retention pattern of the organic polymer layer 31P for the liquid crystal composition 31LC is selected from any one of polymer dispersion, polymer network, and capsule types.

[0049] A polymer-dispersed dimming layer 31 comprises an organic polymer layer 31P that divides into a plurality of isolated voids 31D, and holds the liquid crystal composition 31LC within the voids 31D dispersed in the organic polymer layer 31P. A polymer network dimming layer 31 comprises an organic polymer layer 31P that divides into three-dimensional mesh-like voids 31D, and holds the liquid crystal composition 31LC within the interconnected mesh-like voids 31D. A capsule-type dimming layer 31 holds the liquid crystal composition 31LC within the capsule-shaped voids 31D dispersed in the organic polymer layer 31P.

[0050] The first alignment layer 32 and the second alignment layer 33 respectively control the alignment direction of the nonpolymerizable liquid crystal compound (LCM). The first alignment layer 32 and the second alignment layer 33 appear to be colorless and transparent, or colored and transparent, respectively. The first alignment layer 32 and the second alignment layer 33 are vertical alignment films. The vertical alignment films align the long axis of the nonpolymerizable liquid crystal compound (LCM) with the thickness direction of the dimming layer 31, allowing visible light to pass through the dimming layer 31.

[0051] The materials constituting the first orientation layer 32 and the second orientation layer 33 are organic polymer compounds or inorganic oxides. The organic polymer compound is selected from any one of polyimide, polyimide, polyvinyl alcohol, and cyanide compounds. The inorganic oxide is selected from any one of silicon oxide, zirconium oxide, and organosilicon.

[0052] The first transparent electrode layer 34 and the second transparent electrode layer 35 appear to be colorless and transparent, or colored and transparent, respectively. The materials constituting the first transparent electrode layer 34 and the second transparent electrode layer 35 are conductive inorganic oxides, metals, or conductive organic polymers, respectively. An example of a conductive inorganic oxide is any one selected from indium tin oxide, fluorine-doped tin oxide, tin oxide, and zinc oxide. The metal is gold or silver nanowires. An example of a conductive organic polymer is any one selected from carbon nanotubes and poly(3,4-ethylenedioxythiophene).

[0053] The first transparent support layer 36 and the second transparent support layer 37 appear to be colorless and transparent, or colored and transparent, respectively. The materials constituting the first transparent support layer 36 and the second transparent support layer 37 are organic polymer compounds or inorganic polymer compounds, respectively. An example of an organic polymer compound is selected from polyester, polyacrylate, polycarbonate, and polyolefin. An example of an inorganic polymer compound is selected from silicon oxide, silicon oxynitride, and silicon nitride.

[0054] The driving unit 12 is connected to the first transparent electrode layer 34 and the second transparent electrode layer 35, respectively. The driving unit 12 applies a driving voltage between the first transparent electrode layer 34 and the second transparent electrode layer 35. The driving voltage is a voltage used to change the orientation state of the non-polymerizable liquid crystal compound (LCM). The driving unit 12 changes the orientation state of the LCM, switching the dimming sheet 11 from a transparent state to an opaque state. The opaque state has a lower parallel line transmittance and a higher haze than the transparent state.

[0055] When the driving voltage is released, the non-polymerizable liquid crystal compound (LCM) receives an alignment control force from the first alignment layer 32 and the second alignment layer 33, and the long axis of the non-polymerizable LCM is along the thickness direction of the dimming layer 31. As a result, the dimming sheet 11 suppresses scattering in the dimming layer 31 across the entire visible light region and becomes transparent.

[0056] When the driving voltage is initially applied, the non-polymerizable liquid crystal compound (LCM) is subjected to an orientation control force generated by the electric field, and its long axis begins to move in a direction orthogonal to the electric field direction. At this time, the long axis of the LCM is constrained by the intermolecular interactions and the size of the gaps 31D in the liquid crystal composition 31LC, and cannot move completely, becoming disordered. As a result, the dimming sheet 11 generates scattering in the dimming layer 31 throughout the visible light region, becoming opaque.

[0057] When the driving voltage is released again, the alignment control force generated by the electric field is released from the non-polymerizable liquid crystal compound (LCM). Following the alignment control forces generated by the first alignment layer 32 and the second alignment layer 33, the long axis of the non-polymerizable liquid crystal compound (LCM) is aligned with the thickness direction of the dimming layer 31. As a result, the dimming sheet 11 suppresses scattering in the dimming layer 31 throughout the visible light region and becomes transparent again.

[0058] Furthermore, if the configuration of the transparent and opaque states of the dimming sheet 11 is switched according to the change in the orientation state of the non-polymerizable liquid crystal compound (LCM) caused by the application of voltage, the first alignment layer 32 and the second alignment layer 33 can also be omitted from the dimming sheet 11. In this case, the first surface 31F of the dimming layer 31 contacts the first transparent electrode layer 34, and the second surface 31S of the dimming layer 31 contacts the second transparent electrode layer 35. That is, the driving mode of the dimming sheet 11 can also be changed from a reverse type to a forward type.

[0059] When the first alignment layer 32 and the second alignment layer 33 are omitted, the non-polymerizable liquid crystal compound (LCM) will not be subject to alignment control force when the driving voltage is released, and the long axis direction of the non-polymerizable liquid crystal compound (LCM) becomes disordered. As a result, the dimming sheet 11 generates scattering from the dimming layer 31 throughout the visible light region, becoming opaque.

[0060] When a driving voltage is applied, the non-polymerizable liquid crystal compound (LCM) is subjected to an orientation control force generated by the electric field, and the long axis of the non-polymerizable LCM becomes aligned with the direction of the electric field. As a result, the dimming sheet 11 suppresses scattering in the dimming layer 31 across the entire visible light region and becomes transparent.

[0061] When the driving voltage is released again, the orientation control force generated by the electric field is released from the non-polymerizable liquid crystal compound (LCM), and the long axis direction of the non-polymerizable LCM becomes disordered. As a result, the dimming sheet 11 generates scattering in the dimming layer 31 throughout the visible light region, and becomes opaque again.

[0062] [Dimming Sheets]

[0063] like Figure 2 As shown, the dimming layer 31 comprises an organic polymer layer 31P, a liquid crystal composition 31LC, and spacers SP. The organic polymer layer 31P defines voids 31D that are filled by the liquid crystal composition 31LC. The organic polymer layer 31P defines a plurality of voids 31D. Voids 31D can be isolated from or connected to other adjacent voids 31D. The voids 31D have two or more sizes, including relatively large voids 31H1 and relatively small voids 31H2. The shape of the voids 31D can be spherical, ellipsoidal, or irregular.

[0064] [Photopolymerizable compounds]

[0065] The organic polymer layer 31P is a cured product of a photopolymerizable compound. The photopolymerizable compound can be an ultraviolet-curable compound or an electron beam-curable compound. The photopolymerizable compound is compatible with the liquid crystal composition 31LC. When improving the dimensional control of the voids 31D, the photopolymerizable compound is preferably an ultraviolet-curable compound. An example of an ultraviolet-curable compound is that it contains polymerizable unsaturated bonds at the ends of its molecular structure. Alternatively, the ultraviolet-curable compound may contain polymerizable unsaturated bonds outside the ends of its molecular structure. The photopolymerizable compound is one polymerizable compound or a combination of two or more polymerizable compounds.

[0066] The UV-curable compound is selected from at least one of acrylate compounds, methacrylate compounds, styrene compounds, thiols, and oligomers of these compounds.

[0067] Acrylic ester compounds include monoacrylate compounds, diacrylate compounds, triacrylate compounds, and tetraacrylate compounds. Examples of acrylate compounds include butyl ethyl acrylate, ethylhexyl acrylate, and cyclohexyl acrylate. Examples of methacrylate compounds include dimethacrylate compounds, trimethacrylate compounds, and tetramethacrylate compounds. Examples of methacrylate compounds include N,N-dimethylaminoethyl methacrylate, phenoxyethyl methacrylate, methoxyethyl methacrylate, and tetrahydrofurfuryl methacrylate. Examples of thiols are 1,3-propanedithiol and 1,6-hexanedithiol. Examples of styrene compounds are styrene and methylstyrene.

[0068] The lower limit of the content of organic polymer layer 31P relative to the total amount of organic polymer layer 31P and liquid crystal composition 31LC is 20% by mass, and more preferably, the lower limit of the content is 30% by mass. The upper limit of the content of organic polymer layer 31P relative to the total amount of organic polymer layer 31P and liquid crystal composition 31LC is 70% by mass, and more preferably, the upper limit of the content is 60% by mass.

[0069] The lower and upper limits of the organic polymer layer 31P content are the ranges within which liquid crystal particles formed by the liquid crystal composition 31LC undergo phase separation from the cured product of the photopolymerizable compound during the curing process. When it is necessary to increase the mechanical strength of the organic polymer layer 31P, a higher lower limit of the organic polymer layer 31P content is preferred. When it is necessary to reduce the driving voltage of the non-polymerizable liquid crystal compound LCM, a lower upper limit of the organic polymer layer 31P content is preferred.

[0070] [Liquid Crystal Composition]

[0071] Liquid crystal composition 31LC is a polymer-dispersed liquid crystal composition. Liquid crystal composition 31LC contains a non-polymerizable liquid crystal compound LCM and a non-polymerizable viscosity reducer DP, which fill the voids 31D. Liquid crystal composition 31LC may also contain dichroic pigments, defoamers, antioxidants, weathering agents, and solvents. An example of a weathering agent is an ultraviolet absorber or a light stabilizer.

[0072] [Non-polymerizable liquid crystal compounds]

[0073] The dielectric constant along the long axis of a non-polymerizable liquid crystal compound (LCM) is greater than that along the short axis, exhibiting positive dielectric anisotropy. Alternatively, the dielectric constant along the long axis of the LCM is lower than that along the short axis, exhibiting negative dielectric anisotropy. The dielectric anisotropy of the LCM is appropriately selected based on the presence or absence of each alignment layer and the driving pattern in the dimming sheet 11.

[0074] Nonpolymerizable liquid crystal compounds (LCMs) are selected from at least one of the following: Schiff base compounds, azo compounds, azo oxide compounds, biphenyl compounds, terphenyl compounds, benzoate compounds, diphenylacetylene compounds, pyrimidine compounds, pyridazine compounds, cyclohexane carbonate compounds, phenylcyclohexane compounds, biphenylcyclohexane compounds, dicyanophenyl compounds, naphthalene compounds, and dioxane compounds. A nonpolymerizable liquid crystal compound (LCM) is one liquid crystal compound or a combination of two or more liquid crystal compounds.

[0075] An example of a nonpolymerizable liquid crystal compound (LCM) is represented by the following formula (10).

[0076] R 11 -A 11 -Z 11 -A 12 -Z 12 -A 13 -Z 13 -A 14 -R 12 (10)

[0077] R 11It is an alkyl group with 1 or more hydrogen atoms and less than 20 carbon atoms. R 11 One or more non-adjacent methylene bonds in an alkyl group can be substituted with any one of oxygen atoms, olefin bonds, ester bonds, or diether bonds.

[0078] R 12 It is a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, a difluoromethoxy group, or an alkyl group having 1 or more but less than 15 carbon atoms. R 12 One or more non-adjacent methylene bonds in an alkyl group can be substituted with any one of oxygen atoms, olefin bonds, ester bonds, or diether bonds.

[0079] A 11 A 12 A 13 A 14 Each of these groups independently represents 1,4-phenylene and 2,6-naphthylene. One or more hydrogen atoms in the 1,4-phenylene and 2,6-naphthylene groups can be substituted with fluorine, chlorine, trifluoromethyl, or trifluoromethoxy atoms. A 11 A 12 A 13 A 14 They can also be 1,4-cyclohexene, 3,6-cyclohexenyl, 1,3-dioxane-2,5-diyl, and pyridine-2,5-diyl, each independently. A 13 A 14 They can also be single keys independently.

[0080] Z 11 Z 12 Z 13 Each can be independently represented by any one of the following: single bond, ester bond, diether bond, alkene bond, fluoroalkene bond, or carbonyl bond.

[0081] The orientation state of a nonpolymeric liquid crystal compound (LCM) changes nonlinearly with respect to changes in potential difference, becoming slower at lower temperatures. Changing the orientation of the long axis of the LCM within the voids 31D defined by the organic polymer layer 31P is particularly difficult compared to structures like liquid crystal panels used in display devices, where the liquid crystal composition 31LC fills a wide, layered space. The responsiveness of the LCM is highly dependent on the intermolecular interactions within it.

[0082] The Ni point (NI) of a nonpolymerizable liquid crystal compound (LCM) is the temperature at which it transitions from a nematic phase (N phase) to an isotropic liquid phase (I phase). The Ni point indicates the degree to which the anisotropy of the LCM disappears at ambient temperature. Furthermore, the Ni point largely reflects the degree of intermolecular interactions within the LCM.

[0083] When a nonpolymerizable liquid crystal compound (LCM) is a combination of two or more liquid crystal compounds, the Ni (Noise) point of the LCM is the weighted average of the Ni points of each liquid crystal compound after weighting the proportions of each compound. The Ni point of the LCM can increase or decrease depending on the composition of the two or more liquid crystal compounds with different Ni points.

[0084] When it is required to improve the orientation order of nonpolymerizable liquid crystal compounds (LCMs) at high ambient temperatures such as 100°C, a high Ni point is preferred, more preferably 100°C or higher. When it is required to improve the homogenization of nonpolymerizable liquid crystal compounds (LCMs) and photopolymerizable compounds, a low Ni point is preferred, more preferably 145°C or lower.

[0085] The CN point of a nonpolymerizable liquid crystal compound (LCM) is the temperature at which it undergoes a phase transition from the crystalline phase (C phase) to the nematic phase (N phase). The CN point indicates the degree to which the LCM loses its fluidity at ambient temperature. Furthermore, the CN point largely reflects the degree of intermolecular interactions within the LCM.

[0086] When a nonpolymerizable liquid crystal compound (LCM) is a combination of two or more liquid crystal compounds, the CN point of the LCM is the weighted average of the CN points of each liquid crystal compound after weighting the proportions of each compound. The CN point of the LCM can increase or decrease depending on the composition of the two or more liquid crystal compounds whose CN points differ from each other.

[0087] When it is required to improve the flowability of non-polymerizable liquid crystal compounds (LCMs) at low ambient temperatures such as -20°C, the CN point is preferably low, more preferably below 25°C, and even more preferably below 0°C.

[0088] The refractive index difference Δn (Δn = anomalous refractive index ne - normal refractive index no) between the long and short axes of a nonpolymerizable liquid crystal compound (LCM) indicates the degree of intermolecular interaction within the LCM. Additionally, the refractive index difference Δn of an LCM is the difference in refractive index at a wavelength of 650 nm, representing the degree of visible light scattering when and without a driving voltage applied. When the LCM is a combination of two or more liquid crystal compounds, the upper limit of the refractive index difference Δn is obtained from the refractive index difference Δn of all the liquid crystal compounds. The lower limit of the refractive index difference Δn is also obtained from the refractive index difference Δn of all the liquid crystal compounds.

[0089] When it is required to improve the orientation controllability of non-polymerizable liquid crystal compound (LCM) at high ambient temperatures, a high lower limit value of the refractive index difference Δn is preferred. Furthermore, when it is required to improve the haze difference between the transparent and opaque states, a high lower limit value of the refractive index difference Δn is preferred. When it is required to improve the orientation controllability of non-polymerizable liquid crystal compound (LCM) at high ambient temperatures such as 100°C, a lower limit value of the refractive index difference Δn of the non-polymerizable liquid crystal compound (LCM) is preferably 0.005, more preferably 0.01. Alternatively, when it is required to improve the haze difference, a lower limit value of the refractive index difference Δn of the non-polymerizable liquid crystal compound (LCM) is preferably 0.005, more preferably 0.01.

[0090] When improved transmittance responsiveness at low ambient temperatures is required, a low upper limit for the refractive index difference Δn is preferred. When further improved transmittance responsiveness is required at low ambient temperatures such as -20°C, the upper limit for the refractive index difference Δn of the nonpolymerizable liquid crystal compound LCM is 0.028, more preferably 0.02.

[0091] [Non-polymerizable viscosity reducer]

[0092] Nonpolymerizable viscosity reducer DP contains nonpolar groups such as alkyl groups that weaken the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds (LCMs). Nonpolymerizable viscosity reducer DP also contains polar groups such as ester bonds that interact with the polarity of the nonpolymerizable liquid crystal compound (LCM).

[0093] A nonpolymerizable viscosity reducer DP is represented by either formula (1) or formula (3) below. An example of a nonpolymerizable viscosity reducer DP represented by formula (1) is at least one selected from dibutyl adipate, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis(2-butoxyethyl) adipate, diethyl malonate, di-n-butyl phthalate, bis(2-ethylhexyl) phthalate, tri(2-ethylhexyl) trimellitate, tributyl o-acetyl citrate, and methyl benzoate. An example of a viscosity reducer DP represented by formula (3) is at least one selected from tripropyl phosphate, tributyl phosphate, and tripentyl phosphate. A nonpolymerizable viscosity reducer DP is one viscosity reducer or a combination of two or more viscosity reducers.

[0094] [Chemical structural formula 4]

[0095]

[0096] In formula (1), X is a straight-chain or branched alkyl or aryl group with 1 or more but less than 6 carbon atoms. R in formula (1) 1 R 2 R 3 Each is independently a hydrogen atom or a functional group as shown in formula (2). r in formula (1) 4 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms.

[0097] [Chemical structural formula 5]

[0098]

[0099] r in equation (2) 5 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms.

[0100] [Chemical structural formula 6]

[0101]

[0102] r in equation (3) 6 r 7 r 8 Each is independently a straight-chain alkyl group or an ether group with 3 or more but less than 6 carbon atoms.

[0103] The lower limit of the content of the nonpolymerizable viscosity reducer DP relative to the total amount of the nonpolymerizable liquid crystal compound LCM and the nonpolymerizable viscosity reducer DP is 0.6% by mass, more preferably 1% by mass, and even more preferably 2% by mass. The upper limit of the content of the nonpolymerizable viscosity reducer DP relative to the total amount of the nonpolymerizable liquid crystal compound LCM and the nonpolymerizable viscosity reducer DP is 10% by mass, more preferably 8% by mass, and even more preferably 6% by mass.

[0104] When improved orientation control of nonpolymerizable liquid crystal compounds (LCMs) at high ambient temperatures is required, a low upper limit for the content of the nonpolymerizable viscosity reducer DP is preferred. When improved transmittance responsiveness at low ambient temperatures is required, a high upper limit for the content of the nonpolymerizable liquid crystal compound (LCM) is preferred.

[0105] Dichroic pigments exhibit color based on a host-guest pattern driven by a non-polymerizable liquid crystal compound (LCM). Dichroic pigments are selected from at least one of polyiodide, azo compounds, anthraquinone compounds, naphthoquinone compounds, azomethyl compounds, tetrazine compounds, quinoline compounds, anthocyanin compounds, dinaphthalene-benzene compounds, and dioxazine compounds. A dichroic pigment is one compound or a combination of two or more compounds.

[0106] When improved lightfastness and dichroism ratio are required, the dichroic pigment is selected from at least one of azo compounds and anthraquinone compounds, more preferably an azo compound.

[0107] The spacer SP is dispersed throughout the organic polymer layer 31P. The spacer SP defines the thickness of the dimming layer 31 around its periphery, while simultaneously ensuring uniform thickness of the dimming layer 31. The spacer SP can be a bead-shaped spacer or a photolithographic spacer formed by exposure and development of a photoresist. The spacer SP can be colorless and transparent or colored and transparent. When the liquid crystal composition 31LC contains a dichroic pigment, the color exhibited by the spacer SP is preferably the same as the color exhibited by the dichroic pigment.

[0108] Furthermore, as long as the switching between the transparent and opaque states of the dimming sheet 11 is based on the change in the orientation state of the non-polymerizable liquid crystal compound (LCM) caused by the application of voltage, the dimming sheet 11 can also possess other functional layers. These other functional layers can be gas barrier layers that suppress the transmission of oxygen or moisture into the dimming layer 31, or ultraviolet barrier layers that suppress the transmission of ultraviolet light other than a specific wavelength into the dimming layer 31. Other functional layers can also be hard coatings that mechanically protect the layers of the dimming sheet 11, or adhesive layers that improve the interlayer adhesion of the dimming sheet 11.

[0109] [Manufacturing method of dimming sheet]

[0110] A method for manufacturing the dimming sheet 11 includes forming a coating film comprising the aforementioned photopolymerizable compound and liquid crystal composition 31LC between a first transparent support layer 36 and a second transparent support layer 37. The first transparent support layer 36 includes a first alignment layer 32 and a first transparent electrode layer 34. The second transparent support layer 37 includes a second alignment layer 33 and a second transparent electrode layer 35. Alternatively, in a method for manufacturing the dimming sheet 11 that omits the first alignment layer 32 and the second alignment layer 33, a coating film comprising the aforementioned photopolymerizable compound and liquid crystal composition 31LC is formed between the first transparent support layer 36 and the second transparent support layer 37. The first transparent support layer 36 omits the first alignment layer 32 and instead includes the first transparent electrode layer 34. The second transparent support layer 37 omits the second alignment layer 33 and instead includes the second transparent electrode layer 35.

[0111] The coating contains a polymerization initiator for initiating the polymerization of a photopolymerizable compound. The polymerization initiator is selected from at least one of diketone compounds, acetophenone compounds, benzoin compounds, benzophenone compounds, and thioxanthone compounds. The polymerization initiator can be a single compound or a combination of two or more compounds. An example of a polymerization initiator is any one selected from benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and cyclohexylphenyl ketone.

[0112] The method for manufacturing the dimming sheet 11 includes separating liquid crystal particles formed from the liquid crystal composition 31LC from the polymer by polymerizing a photopolymerizable compound in a coating film. The light that polymerizes the photopolymerizable compound can be ultraviolet light or an electron beam. The light irradiating the coating film can be directed toward the first transparent support layer 36, the second transparent support layer 37, or a combination thereof.

[0113] Phase separation of the liquid crystal particles formed from the liquid crystal composition 31LC is achieved through polymerization of the photopolymerizable compound and diffusion of the liquid crystal composition 31LC. The polymerization rate of the photopolymerizable compound varies with the intensity of light irradiating the photopolymerizable compound. The diffusion rate of the liquid crystal composition 31LC varies with the processing temperature during the polymerization of the photopolymerizable compound. In the phase separation of the liquid crystal composition 31LC, the intensity of light irradiating the photopolymerizable compound is set in a manner that allows the size of the liquid crystal particles to be the desired size, that is, in a manner that allows the size of the gaps 31D to be the desired size. In addition, heating may be performed in the phase separation of the liquid crystal composition 31LC to promote the diffusion of the liquid crystal composition 31LC.

[0114] When it is desirable to reduce the size of the gap 31D, it is preferable to increase the intensity of the light irradiating the photopolymerizable compound and to perform polymerization at a low temperature used to suppress the diffusion of the liquid crystal composition 31LC. When it is desirable to increase the size of the gap 31D, it is preferable to decrease the intensity of the light irradiating the photopolymerizable compound and to perform polymerization at a high temperature used to promote the diffusion of the liquid crystal composition 31LC.

[0115] [Example]

[0116] The following shows specific embodiments and comparative examples of the dimming sheet 11. Furthermore, each embodiment and comparative example is a forward-oriented dimming sheet 11 omitting the first alignment layer 32 and the second alignment layer 33. Furthermore, the dimming sheet 11 is obtained by forming a coating containing a photopolymerizable compound and a liquid crystal composition 31LC between a first transparent support layer 36 having a first transparent electrode layer 34 and a second transparent support layer 37 having a second transparent electrode layer 35, and by polymerizing the photopolymerizable compound in the coating.

[0117] Furthermore, the constituent materials used in the examples and comparative examples are shown below. The Ni point of the non-polymerizable liquid crystal compound (LCM) is 110°C. Additionally, the proportions of the constituent materials in Examples 1-41 and Comparative Examples 1-7 are shown below. Figures 3-7 middle. Figures 3-7 The mixing ratios shown indicate the proportions of each constituent material relative to the total amount of coating liquid used to form the coating film.

[0118] • First transparent electrode layer 34: Indium tin oxide

[0119] Second transparent electrode layer 35: Indium tin oxide

[0120] • First transparent support layer 36: Polyethylene terephthalate film

[0121] Second transparent support layer 37: Polyethylene terephthalate film

[0122] • Polymerization initiator PI1: 1-Hydroxycyclohexylphenyl ketone

[0123] Non-polymerizable liquid crystal compounds (LCMs): cyanobiphenyl compounds

[0124] • Spacer SP: Perfectly spherical with a diameter of 15 μm (made of PMMA)

[0125] • Ultraviolet-activated polymerizable compounds (polymerizable unsaturated compounds)

[0126] Ingredient M1: Isoborneol acrylate

[0127] Ingredient M2: Pentaerythritol triacrylate

[0128] Ingredient M3: Carbamate acrylate - non-polymerizable viscosity reducer DP (non-polymerizable additive)

[0129] Ingredient NPA1: Dibutyl adipic acid

[0130] Ingredient NPA2: Dioctyl adipic acid

[0131] Ingredient NPA3: Diisononyl adipic acid

[0132] Ingredient NPA4: Diisodecyl adipic acid ester

[0133] Ingredient NPA5: Bis(2-butoxyethyl) adipic acid ester

[0134] Ingredient NPA6: Diethyl malonate

[0135] Ingredient NPA7: Di-n-butyl phthalate

[0136] Ingredient NPA8: Bis(2-ethylhexyl) phthalate

[0137] Ingredient NPA9: Tris(2-ethylhexyl) trimellitate

[0138] Ingredient NPA10: Tributyl o-acetyl citrate

[0139] Ingredient NPA11: Methyl benzoate

[0140] Ingredient NPA12: Tributyl phosphate

[0141] Polymerizing additives

[0142] Ingredient MA1: Butyl acrylate

[0143] Ingredient MA2: Triethylene glycol diacrylate

[0144] Ingredient MA3: Pentaerythritol triacrylate

[0145] (Examples 1 to 6)

[0146] like Figure 3 As shown, the coating solutions of Examples 1 to 6 each used 0.5% by mass of components NPA1 to NPA6 as non-polymerizable viscosity reducers DP. Using the coating solutions of Examples 1 to 6, a coating film with a thickness of 20 μm was formed on the first transparent electrode layer 34, and spacers SP were dispersed in the coating film. Then, the coating film with dispersed spacers SP was laminated through the first transparent electrode layer 34 and the second transparent electrode layer 35, and ultraviolet light of 365 nm was irradiated toward the first transparent support layer 36 to obtain the dimming sheet 11 of Examples 1 to 6. At this time, the intensity of the ultraviolet light was set to 10 mW / cm. 2Set the ultraviolet irradiation time to 100 seconds.

[0147] (Examples 7 to 12)

[0148] like Figure 3 and Figure 4 As shown, the coating liquids of Examples 7 to 12 each used 1.0% by mass of components NPA1 to NPA6 as non-polymerizable viscosity reducers DP. Except for the proportions of the non-polymerizable viscosity reducer DP and the proportions of the UV-polymerizable compound, the same procedures as in Example 1 were followed to obtain the dimming sheets 11 of Examples 7 to 12.

[0149] (Examples 13 to 18)

[0150] like Figure 4 As shown, the coating liquids of Examples 13 to 18 each used 2.0% by mass of components NPA1 to NPA6 as non-polymerizable viscosity reducers DP. Except for the proportions of the non-polymerizable viscosity reducer DP and the proportions of the UV-polymerizable compound, the same procedures as in Example 1 were followed to obtain the dimming sheets 11 of Examples 13 to 18.

[0151] (Examples 19-30)

[0152] like Figure 4 and Figure 5 As shown, the coating liquids of Examples 19 to 30 each used 3.0% by mass of components NPA1 to NPA12 as non-polymerizable viscosity reducers DP. Except for the proportions of the non-polymerizable viscosity reducer DP and the proportions of the UV-polymerizable compound, the same procedures as in Example 1 were followed to obtain the dimming sheets 11 of Examples 19 to 30.

[0153] (Examples 31 to 36)

[0154] like Figure 6 As shown, the coating liquids of Examples 31 to 36 each used 4.0% by mass of components NPA1 to NPA6 as non-polymerizable viscosity reducers DP. Except for the proportions of the non-polymerizable viscosity reducer DP and the proportions of the UV-polymerizable compound, the same procedures as in Example 1 were followed to obtain the dimming sheets 11 of Examples 31 to 36.

[0155] (Examples 37 to 39)

[0156] like Figure 6As shown, the coating liquids of Examples 37 to 39 used 5.0% by mass of components NPA3, NPA5, and NPA6 as non-polymerizable viscosity reducers DP, respectively. Except for the proportions of the non-polymerizable viscosity reducer DP and the proportions of the UV-polymerizable compound, the same procedures as in Example 1 were followed to obtain the dimming sheets 11 of Examples 37 to 39.

[0157] (Examples 40-41)

[0158] like Figure 6 As shown, the coating liquids of Examples 40 and 41 used 0.3% by mass of component NPA4 and component NPA6 as non-polymerizable viscosity reducers DP, respectively. Except for the proportion of the non-polymerizable viscosity reducer DP and the proportion of the UV-polymerizable compound, the same procedure as in Example 1 was followed to obtain the dimming sheets 11 of Examples 40 and 41.

[0159] (Comparative Example 1)

[0160] In addition to Figure 7 The method shown is the same as in Example 1, except that the coating liquid omitting the non-polymerizable viscosity reducer DP and the proportion of the ultraviolet polymerizable compound are omitted. The dimming sheet 11 of Comparative Example 1 is obtained by operating in the same manner as in Example 1.

[0161] (Comparative Examples 2 to 3)

[0162] In addition to Figure 7 The finishing liquid shown was used with the non-polymerizable viscosity reducer DP omitted, and 0.5% by mass of component MA1 added as a polymerizable additive was added. Except for the proportions of the non-polymerizable viscosity reducer DP omitted, the polymerizable additive added, and the ultraviolet polymerizable compound, the same operation as in Example 1 was performed to obtain the dimming sheet 11 of Comparative Example 2.

[0163] In addition, except for the use of a coating liquid that omits the non-polymerizable viscosity reducer DP, adds 4.0% by mass of component MA1 as a polymerizable additive, and the proportions of the polymerizable additive and the ultraviolet polymerizable compound, the same procedure as in Example 1 was followed to obtain the dimming sheet 11 of Comparative Example 3.

[0164] (Comparative Examples 4-5)

[0165] In addition to Figure 7The finishing liquid shown was used with the non-polymerizable viscosity reducer DP omitted, and 0.5% by mass of component MA2 added as a polymerizable additive added. Except for the proportions of the non-polymerizable viscosity reducer DP omitted, the polymerizable additive added, and the ultraviolet polymerizable compound, the same operation as in Example 1 was performed to obtain the dimming sheet 11 of Comparative Example 4.

[0166] In addition, except for the use of a coating liquid that omits the non-polymerizable viscosity reducer DP, adds 4.0% by mass of component MA2 as a polymerizable additive, and the proportions of the polymerizable additive and the ultraviolet polymerizable compound, the same procedure as in Example 1 was followed to obtain the dimming sheet 11 of Comparative Example 5.

[0167] (Comparative Examples 6-7)

[0168] In addition to Figure 7 The finishing liquid shown was used with the non-polymerizable viscosity reducer DP omitted, and 0.5% by mass of component MA3 added as a polymerizable additive was added. Except for the proportions of the non-polymerizable viscosity reducer DP omitted, the polymerizable additive added, and the ultraviolet polymerizable compound, the same operation as in Example 1 was performed to obtain the dimming sheet 11 of Comparative Example 6.

[0169] In addition, except for the use of a coating liquid that omits the non-polymerizable viscosity reducer DP, adds 4.0% by mass of component MA3 as a polymerizable additive, and the proportions of the polymerizable additive and the ultraviolet polymerizable compound, the same procedure as in Example 1 was followed to obtain the dimming sheet 11 of Comparative Example 7.

[0170] [evaluate]

[0171] Using the dimming sheets 11 of Examples 1 to 41 and Comparative Examples 1 to 7, the haze of the dimming sheets 11 in the opaque state (when not powered on) and the haze of the dimming sheets 11 in the transparent state (when powered on) were measured at various temperatures of -20°C, -10°C, 0°C, 23°C, 90°C, and 100°C.

[0172] The dimming sheets 11 of Examples 1-41 and Comparative Examples 1-7 were used for ON operation, and the time required for the dimming sheets 11 to switch from an opaque state to a transparent state was measured at temperatures of -20°C, -10°C, and 23°C. The time required to switch from an opaque state to a transparent state is the time from the start of applying the driving voltage until the haze of the dimming sheets 11 stabilizes.

[0173] The dimming sheets 11 of Examples 1-41 and Comparative Examples 1-7 were used for OFF operation, and the time required for the dimming sheets 11 to switch from a transparent state to an opaque state was measured at various temperatures of -20°C, -10°C, and 23°C. The time required to switch from a transparent state to an opaque state is the time from when the application of the driving voltage is stopped until the haze of the dimming sheets 11 stabilizes.

[0174] It can be seen that the ON action at -20°C in Examples 1 to 41 is less than 5 seconds, while the ON action at -20°C in Comparative Examples 1 to 7 is more than 7 seconds. Therefore, it is evident that by adding components NPA1 to NPA12 as non-polymerizable viscosity reducers (DP), the responsiveness of the ON action at -20°C can be improved compared to the case without adding non-polymerizable viscosity reducers (DP) or with adding polymerizable additives.

[0175] Furthermore, it can be seen that the deviation between the ON action at -20°C and the ON action at 23°C was less than 4 seconds in Examples 1 to 41, while it was more than 6 seconds in Comparative Examples 1 to 7. Therefore, it is evident that by adding components NPA1 to NPA12 as non-polymerizable viscosity reducers (DP), compared to not adding non-polymerizable viscosity reducers (DP) or adding polymerizable additives, the degree of decrease in ON action responsiveness due to temperature reduction can be suppressed.

[0176] Furthermore, it can be seen that the haze in the transparent state of Examples 1 to 39 is all below 6%, while the haze in the transparent state of Examples 40 to 41 is above 7%. Therefore, it is evident that if the weight ratio of the nonpolymerizable viscosity reducer DP to the nonpolymerizable liquid crystal compound LCM is 1% or more, the haze in the transparent state can be suppressed.

[0177] A comparison of the haze in the transparent state of Examples 7 to 39 with the haze in the transparent state of Examples 1 to 6 shows that if the proportion of the nonpolymerizable viscosity reducer DP to the nonpolymerizable liquid crystal compound LCM by weight is 2% or more, the haze in the transparent state can be further suppressed.

[0178] It can be seen that the haze in the opaque state of Examples 33, 35, and 36 is above 85% at 100°C, while the haze in the opaque state of Examples 37, 38, and 39 is below 83% at 100°C. Therefore, it is evident that if the weight ratio of the nonpolymerizable viscosity reducer DP to the nonpolymerizable liquid crystal compound LCM is 8% or less, the reduction in haze in the opaque state can be suppressed.

[0179] Furthermore, it can be seen that the deviation between the haze of the opaque state at -20°C and the haze of the opaque state at 23°C is less than 10% in Examples 33, 35, and 36, while it is more than 12% in Examples 37, 38, and 39. Therefore, it is evident that if the weight ratio of the nonpolymerizable viscosity reducer DP to the nonpolymerizable liquid crystal compound LCM is 8% or less, the degree of haze reduction in the opaque state due to temperature decrease can be suppressed.

[0180] It is evident that the haze of the transparent state at -20°C in Examples 19 to 23 is lower than that in the transparent state at -20°C in Examples 24, 27 to 30. Furthermore, it is evident that the haze of the opaque state at 100°C in Examples 19 to 23 is higher than that in the opaque state at 100°C in Examples 25 to 27. Therefore, when it is required to improve the orientation order of the non-polymerizable liquid crystal compound (LCM) at low ambient temperatures, it is preferable to use components NPA1 to NPA6 in the non-polymerizable LCM. Additionally, when it is required to improve the flowability of the non-polymerizable LCM at high ambient temperatures, it is also preferable to use components NPA1 to NPA6 in the non-polymerizable LCM.

[0181] According to the above implementation method, the following effects can be obtained.

[0182] (1) If the liquid crystal composition 31LC contains the nonpolymerizable viscosity reducer DP shown in formulas (1) to (3) above, then the alkyl groups exist as nonpolar groups between the nonpolymerizable liquid crystal compounds LCM, weakening the intermolecular interactions of the nonpolymerizable liquid crystal compounds LCM. As a result, the responsiveness of the transmittance at low ambient temperatures such as -20°C can be improved.

[0183] (2) If it is a low molecular structure represented by the above formulas (1) to (3), it is suitable for diffusion from the polymer of the ultraviolet polymerizable compound, that is, as liquid crystal particles, phase separation occurs from the organic polymer layer 31P.

[0184] (3) As with components NPA1 to NPA6, when the nonpolymerizable viscosity reducer DP is adipate, it can also suppress the reduction of orientation order of nonpolymerizable liquid crystal compound LCM at low ambient temperatures such as -20°C.

[0185] (4) When the weight ratio of the nonpolymerizable viscosity reducer DP to the weight of the nonpolymerizable liquid crystal compound LCM is more than 1%, it can also suppress the reduction of the orientation order of the nonpolymerizable liquid crystal compound LCM at low ambient temperatures such as -20°C.

[0186] (5) When the weight ratio of the nonpolymerizable viscosity reducer DP to the weight of the nonpolymerizable liquid crystal compound LCM is more than 2% and less than 8%, it becomes easier to control the transfer of the nonpolymerizable liquid crystal compound LCM to the disordered phase at high ambient temperatures such as 100°C.

[0187] Furthermore, based on the above implementation methods and embodiments, the following technical concepts can be derived.

[0188] • In the dimming sheet, its manufacturing method, and the polymer-dispersed liquid crystal composition, the liquid crystal composition may contain diisodecyl adipate as a non-polymerizable viscosity reducer, wherein the weight ratio of the non-polymerizable viscosity reducer to the non-polymerizable liquid crystal compound is 1% or more and 8% or less. Alternatively, in the dimming sheet, its manufacturing method, and the polymer-dispersed liquid crystal composition, the liquid crystal composition may contain any one of dibutyl adipate, dioctyl adipate, and diisononyl adipate as a non-polymerizable viscosity reducer, wherein the weight ratio of the non-polymerizable viscosity reducer to the non-polymerizable liquid crystal compound is 1% or more and 8% or less. In the dimming sheet, its manufacturing method, and the polymer-dispersed liquid crystal composition, the liquid crystal composition may contain any one of diisodecyl adipate, dibutyl adipate, dioctyl adipate, and diisononyl adipate as a non-polymerizable viscosity reducer, wherein the weight ratio of the non-polymerizable viscosity reducer to the non-polymerizable liquid crystal compound is 1% or more and 8% or less.

[0189] Furthermore, in the dimming sheet, its manufacturing method, and the polymer-dispersed liquid crystal composition, the weight ratio of the organic polymer layer to the total weight of the organic polymer layer and the liquid crystal composition can be 30% by mass or more and 60% by mass or less. Moreover, in the dimming sheet, its manufacturing method, and the polymer-dispersed liquid crystal composition, the weight ratio of the non-polymerizable viscosity reducer to the total weight of the non-polymerizable liquid crystal compound and the non-polymerizable viscosity reducer can be 2% by mass or more and 6% by mass or less.

[0190] Figures 3-7As shown in the OFF operation of component NPA4 at -10°C, when the weight of the non-polymerizable viscosity reducer relative to the weight of the liquid crystal composition is 0.3%, or in other words, when the weight of the non-polymerizable viscosity reducer relative to the weight of the non-polymerizable liquid crystal compound is 0.6%, the OFF operation requires time. However, when the weight of the non-polymerizable viscosity reducer relative to the weight of the liquid crystal composition is 0.5% or more, or in other words, when the weight of the non-polymerizable viscosity reducer relative to the weight of the non-polymerizable liquid crystal compound is 1% or more, the time required for the OFF operation can be drastically shortened. Furthermore, as in the above-described configurations, if the non-polymerizable viscosity reducer includes any one of diisodecyl adipate, dibutyl adipate, dioctyl adipate, and diisononyl adipate, and the weight of the non-polymerizable viscosity reducer relative to the weight of the non-polymerizable liquid crystal compound is 1% or more and 8% or less, the time required for the OFF operation can be drastically shortened. In addition, when the weight of the non-polymerizable viscosity reducer is 2% by mass or more and 6% by mass or less relative to the total weight of the non-polymerizable liquid crystal compound and the non-polymerizable viscosity reducer, the time required for the OFF action can be drastically shortened.

[0191] • It can be: X in formula (1) is a straight-chain alkyl group with 1 or more and 6 or less carbon atoms, and R in formula (1) 1 R 2 R 3 It can be bonded to one carbon atom at the end of a straight-chain alkyl group, or it can be bonded to one carbon atom at the end of a straight-chain alkyl group and another carbon atom at the end of the straight-chain alkyl group. It can be: X in formula (1) is a straight-chain alkyl group with 1 or more carbon atoms and 6 or fewer carbon atoms, and R in formula (1) 1 R 2 R 3 It is bonded to different carbons other than the end of the straight-chain alkyl group. It can be: X in formula (1) is one aryl group, and R in formula (1) is... 1 R 2 R 3 One of the bonds in R is attached to one carbon in the aryl group. 1 R 2 R 3 The remaining two bonds are attached to another carbon in the aryl group. This could be: X in formula (1) is one aryl group, and R in formula (1) 1 R 2 R 3 They are bonded to different carbons in the aryl group.

[0192] Symbol Explanation

[0193] DP nonpolymerizable viscosity reducer

[0194] LCM (Liquid Crystal Compound)

[0195] SP spacers

[0196] 11. Dimming Sheets

[0197] 12 Drive Unit

[0198] 31 Dimming Layer

[0199] 32 First Orientation Layer

[0200] 33 Second Orientation Layer

[0201] 34 First transparent electrode layer

[0202] 35 Second transparent electrode layer

[0203] 36 First transparent support layer

[0204] 37 Second transparent support layer

[0205] 31P Organic Polymer Layer

[0206] 31D gap

[0207] 31LC liquid crystal composition

Claims

1. A dimming sheet comprising an organic polymer layer divided into multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, wherein the transmittance of visible light is changed by driving the non-polymerizable liquid crystal compound. in, The liquid crystal composition comprises a nonpolymerizable viscosity reducer as shown in formula (1), wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compounds. In the formula, X is a straight-chain alkyl or aryl group with 1 or more but less than 6 carbon atoms. When X in formula (1) is a straight-chain alkyl group with 1 or more but less than 6 carbon atoms, R in formula (1) 1 R 2 R 3 It can be bonded to one carbon atom at the end of a straight-chain alkyl group, or to one carbon atom at the end of a straight-chain alkyl group and another carbon atom at the end of the straight-chain alkyl group, or to different carbon atoms other than the end of the straight-chain alkyl group. When X in equation (1) is one aryl group, R in equation (1) 1 R 2 R 3 One of the bonds is attached to a carbon in the aryl group, R 1 R 2 R 3 The remaining two bonds are attached to another carbon in the aryl group, or R in equation (1) 1 R 2 R 3 They are bonded to different carbons in the aryl group. R 1 R 2 R 3 Each is an independent hydrogen atom or a functional group as shown in formula (2); r 4 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. In the formula, r 5 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

2. A dimming sheet comprising an organic polymer layer with multiple pores and a liquid crystal composition containing a non-polymerizable liquid crystal compound and filling the pores, wherein the transmittance of visible light is changed by driving the non-polymerizable liquid crystal compound. in, The liquid crystal composition comprises a nonpolymerizable viscosity reducer as shown in formula (3), wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compounds. In the formula, r 6 r 7 r 8 Each is independently a straight-chain alkyl group with 3 or more but less than 8 carbon atoms. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

3. The dimming sheet according to claim 1 or 2, wherein, The weight of the organic polymer layer relative to the total weight of the organic polymer layer and the liquid crystal composition is 30% by mass or more and 60% by mass or less.

4. The dimming sheet according to claim 1, wherein, In formula (1), X is a straight-chain alkyl group with 1 or more carbon atoms and 6 or fewer. R in equation (1) 1 It is the functional group shown in equation (2). R in equation (1) 2 R 3 Each is an independent hydrogen atom.

5. The dimming sheet according to claim 1, wherein, The NI point of the non-polymerizable liquid crystal compound is above 100°C and below 145°C.

6. The dimming sheet according to any one of claims 1 or 4 to 5, wherein, The nonpolymerizable viscosity reducer is selected from any one of diisodecyl adipate, dibutyl adipate, dioctyl adipate, bis(2-butoxyethyl) adipate, and diisononyl adipate.

7. The dimming sheet according to claim 6, wherein, The weight of all the nonpolymerizable viscosity reducer contained in the liquid crystal composition is 2% by mass and less than 6% by mass relative to the total weight of the nonpolymerizable liquid crystal compound and the nonpolymerizable viscosity reducer.

8. The dimming sheet according to any one of claims 1, 2, 4 to 5, further comprising a first transparent electrode layer and a second transparent electrode layer. The organic polymer layer is located between the transparent electrode layers. The liquid crystal composition is composed of liquid crystal particles that have undergone phase separation from the organic polymer layer. The dimming sheet changes from a transparent state to an opaque state by releasing the voltage applied between the transparent electrode layers.

9. The dimming sheet according to any one of claims 1, 2, 4 to 5, further comprising a first transparent electrode layer and a second transparent electrode layer. The organic polymer layer is located between the transparent electrode layers. The liquid crystal composition is composed of liquid crystal particles separated from the organic polymer layer phase. The dimming sheet changes from a transparent state to an opaque state by applying voltage between the transparent electrode layers.

10. A method for manufacturing a dimming sheet, comprising manufacturing an organic polymer layer having a plurality of pores and a liquid crystal composition having a non-polymerizable liquid crystal compound filling the pores, and a method for changing the transmittance of visible light by driving the non-polymerizable liquid crystal compound, the method comprising: By polymerizing the ultraviolet-curable compound in a layer containing the liquid crystal composition and the ultraviolet-curable compound, liquid crystal particles formed from the liquid crystal composition are phase-separated from the organic polymer layer. in, The liquid crystal composition comprises a nonpolymerizable viscosity reducer as shown in formula (1), wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compounds. In the formula, X is a straight-chain alkyl or aryl group with 1 or more but less than 6 carbon atoms. When X in formula (1) is a straight-chain alkyl group with 1 or more but less than 6 carbon atoms, R in formula (1) 1 R 2 R 3 It can be bonded to one carbon atom at the end of a straight-chain alkyl group, or to one carbon atom at the end of a straight-chain alkyl group and another carbon atom at the end of the straight-chain alkyl group, or to different carbon atoms other than the end of the straight-chain alkyl group. When X in equation (1) is one aryl group, R in equation (1) 1 R 2 R 3 One of the bonds is attached to a carbon in the aryl group, R 1 R 2 R 3 The remaining two bonds are attached to another carbon in the aryl group, or R in equation (1) 1 R 2 R 3 They are bonded to different carbons in the aryl group. R 1 R 2 R 3 Each is an independent hydrogen atom or a functional group as shown in formula (2); r 4 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. In the formula, r 5 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. The weight ratio of the organic polymer layer to the total weight of the organic polymer layer and the liquid crystal composition is 30% by mass or more and 60% by mass or less. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

11. A method for manufacturing a dimming sheet, comprising manufacturing an organic polymer layer having a plurality of pores and a liquid crystal composition having a non-polymerizable liquid crystal compound filling the pores, and a method for changing the transmittance of visible light by driving the non-polymerizable liquid crystal compound, the method comprising: By polymerizing the ultraviolet-curable compound in a layer containing the liquid crystal composition and the ultraviolet-curable compound, liquid crystal particles formed from the liquid crystal composition are phase-separated from the organic polymer layer. in, The liquid crystal composition comprises a nonpolymerizable viscosity reducer as shown in formula (3), wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compounds. In the formula, r 6 r 7 r 8 Each is independently a straight-chain alkyl group with 3 or more but less than 8 carbon atoms. The weight ratio of the organic polymer layer to the total weight of the organic polymer layer and the liquid crystal composition is 30% by mass or more and 60% by mass or less. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

12. A polymer-dispersed liquid crystal composition, wherein the ultraviolet-curable compound is polymerized in a layer comprising a liquid crystal composition and an ultraviolet-curable compound, thereby causing phase separation from the organic polymer layer, which is a polymer. in, The liquid crystal composition comprises a nonpolymerizable liquid crystal compound and a nonpolymerizable viscosity reducer as shown in formula (1), wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compound. In the formula, X is a straight-chain alkyl or aryl group with 1 or more but less than 6 carbon atoms. When X in formula (1) is a straight-chain alkyl group with 1 or more but less than 6 carbon atoms, R in formula (1) 1 R 2 R 3 It can be bonded to one carbon atom at the end of a straight-chain alkyl group, or to one carbon atom at the end of a straight-chain alkyl group and another carbon atom at the end of the straight-chain alkyl group, or to different carbon atoms other than the end of the straight-chain alkyl group. When X in equation (1) is one aryl group, R in equation (1) 1 R 2 R 3 One of the bonds is attached to a carbon in the aryl group, R 1 R 2 R 3 The remaining two bonds are attached to another carbon in the aryl group, or R in equation (1) 1 R 2 R 3 They are bonded to different carbons in the aryl group. R 1 R 2 R 3 Each hydrogen atom or the functional group shown in formula (2) is independent; r 4 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. In the formula, r 5 It is a straight-chain or branched alkyl or ether group with 1 or more but less than 10 carbon atoms. The weight ratio of the UV-curable compound to the total weight of the UV-curable compound and the liquid crystal composition is 30% by mass or more and 60% by mass or less. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

13. A polymer-dispersed liquid crystal composition, wherein the ultraviolet-curable compound is polymerized in a layer comprising a liquid crystal composition and an ultraviolet-curable compound, thereby causing phase separation from the organic polymer layer as a polymer. in, The liquid crystal composition comprises a nonpolymerizable liquid crystal compound and a nonpolymerizable viscosity reducer as shown in formula (3) below, wherein the nonpolymerizable viscosity reducer comprises a nonpolar group for weakening the intermolecular interactions of adjacent nonpolymerizable liquid crystal compounds and a polar group having polarity that interacts with the polarity of the nonpolymerizable liquid crystal compound. In the formula, r 6 r 7 r 8 Each is independently a straight-chain alkyl group with 3 or more but less than 8 carbon atoms. The weight ratio of the UV-curable compound to the total weight of the UV-curable compound and the liquid crystal composition is 30% by mass or more and 60% by mass or less. The weight of the nonpolymerizable viscosity reducer relative to the weight of the nonpolymerizable liquid crystal compound is more than 1% and less than 8%.

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