Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F20/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G75/00—Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule
  • C08G75/02—Polythioethers
  • C08G75/04—Polythioethers from mercapto compounds or metallic derivatives thereof
  • C08G75/045—Polythioethers from mercapto compounds or metallic derivatives thereof from mercapto compounds and unsaturated compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/38—Polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
  • C09K19/54—Additives having no specific mesophase characterised by their chemical composition
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1334—Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals

Definitions

• the present invention relates to a transmission scattering type liquid crystal display element.
• a TN (Twisted Nematic) mode As a liquid crystal display element, a TN (Twisted Nematic) mode has been put into practical use. In this mode, it is necessary to use a polarizing plate in order to switch light by utilizing the optical rotation characteristic of the liquid crystal display. When a polarizing plate is used, the efficiency of light utilization is lowered. As a liquid crystal display element that does not use a polarizing plate, there is an element that switches between a transparent state (also referred to as a transparent state) of a liquid crystal and a scattered state.
• a transparent state also referred to as a transparent state
• a polymer dispersed liquid crystal also referred to as PDLC (Polymer Dispersed Liquid Crystal)
• PDLC Polymer Dispersed Liquid Crystal
• PNLC Polymer Network Liquid Crystal
• liquid crystal display elements a liquid crystal composition containing a polymerizable compound that is polymerized by ultraviolet rays is arranged between a pair of substrates provided with electrodes, and the liquid crystal composition is cured by irradiation with ultraviolet rays to be polymerizable with the liquid crystal. It forms a complex with a cured product of the compound (eg, a polymer network). Then, in this liquid crystal display element, the scattering state and the transmission state of the liquid crystal are controlled by applying a voltage.
• a liquid crystal composition containing a polymerizable compound that is polymerized by ultraviolet rays is arranged between a pair of substrates provided with electrodes, and the liquid crystal composition is cured by irradiation with ultraviolet rays to be polymerizable with the liquid crystal. It forms a complex with a cured product of the compound (eg, a polymer network). Then, in this liquid crystal display element, the scattering state and the transmission state of the liquid crystal are controlled by applying a voltage.
• liquid crystal display element When no voltage is applied to a liquid crystal display element using PDLC or PNLC, the liquid crystal faces in a random direction, resulting in a cloudy (scattering) state. When a voltage is applied, the liquid crystals are arranged in the electric field direction and transmit light. There is a liquid crystal display element that becomes transmissive (also referred to as a normal type element). In this case, since the liquid crystal is random when no voltage is applied, there is no need for a liquid crystal alignment film or alignment treatment for aligning the liquid crystal in one direction. Therefore, in this liquid crystal display element, the electrode and the liquid crystal layer (composite of the above liquid crystal and the cured product of the polymerizable compound) are in direct contact with each other (see Patent Documents 1 and 2).
• the polymerizable compound in the liquid crystal composition has a role of forming a polymer network to obtain desired optical properties and a role of enhancing the adhesion between the liquid crystal layer and the electrode.
• an inorganic electrode such as ITO (Indium Tin Oxide) is used for the liquid crystal display element
• the compatibility with the polymerizable compound of the organic substance, that is, the adhesion tends to be low.
• the adhesion becomes low, the optical characteristics of the element may be peeled off, bubbles may be generated, and the scattered and transparent optical characteristics may occur due to long-term use, especially in a harsh environment such as high temperature and humidity or exposure to light. It is easy to cause a drop.
• the present invention enhances the adhesion between the liquid crystal layer and the electrode, and even in a harsh environment exposed to high temperature and high humidity or light irradiation for a long time, the element peels off, the generation of bubbles, and the optical characteristics. It is an object of the present invention to provide a liquid crystal display element capable of suppressing a decrease in the amount of light.
• the present inventor has completed the present invention having the following gist. That is, it is a liquid crystal display element having a liquid crystal layer obtained by irradiating a liquid crystal composition containing a liquid crystal and a polymerizable composition arranged between a pair of substrates provided with electrodes and curing the liquid crystal, and further, a voltage.
• a transmission-scattering type liquid crystal display element that becomes a scattering state when no application is applied and becomes a transparent state when a voltage is applied, wherein the polymerizable composition has a structure represented by the following formula [1A] (also referred to as a specific structure). It is a liquid crystal display element characterized by containing one or more kinds of compounds having (also referred to as a specific polymerizable compound). (* Indicates a bond.)
• the adhesion between the liquid crystal layer and the electrode is improved, and even in a harsh environment exposed to high temperature and high humidity or light irradiation for a long time, the element is peeled off, bubbles are generated, and the optical characteristics are deteriorated.
• a liquid crystal display element that can be suppressed can be obtained. Therefore, the liquid crystal display element of the present invention can be used for a liquid crystal display for the purpose of display, a dimming window for controlling blocking and transmission of light, an optical shutter element, and the like.
• the liquid crystal composition of the present invention includes a liquid crystal and a polymerizable composition containing a polymerizable compound having a specific structure.
• the liquid crystal composition includes a polymerizable composition containing a liquid crystal and a specific polymerizable compound.
• a liquid crystal a nematic liquid crystal, a smectic liquid crystal or a cholesteric liquid crystal can be used.
• a liquid crystal having a positive dielectric anisotropy is used for the normal type element, and a liquid crystal having a negative dielectric anisotropy is used for the reverse type element.
• a liquid crystal having a positive dielectric anisotropy is preferable.
• liquid crystal two or more kinds of liquid crystals can be mixed and used according to the respective physical property values of the phase transition temperature, the dielectric anisotropy and the refractive index anisotropy.
• the content of the liquid crystal in the liquid crystal composition is preferably 40 to 70% by mass, more preferably 40 to 60% by mass, and 50 to 60% by mass, assuming that the liquid crystal composition is 100% by mass. Is particularly preferred.
• a liquid crystal display element As an active element such as a TFT (Thin Film Transistor), it is required that the electric resistance of the liquid crystal is high and the voltage holding ratio (also referred to as VHR) is high. Therefore, it is preferable to use a fluorine-based or chlorine-based liquid crystal that has high electrical resistance and whose VHR does not decrease due to active energy rays such as ultraviolet rays.
• a dichroic dye in the liquid crystal composition it is also possible to dissolve a dichroic dye in the liquid crystal composition to obtain a guest host type liquid crystal display element.
• a dichroic dye in the liquid crystal composition, an element that absorbs (scatters) when no voltage is applied and becomes transparent when a voltage is applied can be obtained.
• the direction (direction of orientation) of the director of the liquid crystal changes by 90 degrees depending on the presence or absence of voltage application. Therefore, by utilizing the difference in the absorption characteristics of the dichroic dye, this device can obtain a high contrast as compared with the conventional guest-host type device that switches between random orientation and vertical orientation.
• the liquid crystal becomes colored when it is oriented in the horizontal direction and becomes opaque only in the scattered state. Therefore, it is possible to obtain an element that switches from colored opacity when no voltage is applied to a colored transparent state and a colorless transparent state as a voltage is applied.
• the polymerizable composition contains a polymerizable compound.
• the polymerizable compound is for forming a polymer network (also referred to as a curable resin) by a polymerization reaction by irradiation with ultraviolet rays at the time of producing a liquid crystal display element. Therefore, a polymer obtained by polymerizing a polymerizable compound in advance may be introduced into the liquid crystal composition. However, even if it is a polymer, it is necessary to have a site that undergoes a polymerization reaction by irradiation with ultraviolet rays.
• the polymerizable compound it is preferable to use a liquid crystal composition containing the polymerizable compound from the viewpoint of handling the liquid crystal composition, that is, suppressing the increase in viscosity of the liquid crystal composition and the solubility in the liquid crystal.
• the polymerizable compound is not particularly limited as long as it is dissolved in the liquid crystal, but when the polymerizable compound is dissolved in the liquid crystal, it is necessary that a part or the whole of the liquid crystal composition has a temperature at which the liquid crystal phase is exhibited. Even when a part of the liquid crystal composition exhibits a liquid crystal phase, it is sufficient that the liquid crystal display element is visually confirmed and the entire inside of the element is obtained with substantially uniform transparency and scattering characteristics.
• the polymerizable compound may be any compound that is polymerized by ultraviolet rays, and at that time, the polymerization may proceed in any reaction form to form a curable resin.
• Specific reaction types include radical polymerization, cationic polymerization, anionic polymerization or polyaddition reaction.
• the reaction type of the polymerizable compound is preferably radical polymerization from the viewpoint of the optical characteristics of the liquid crystal display element.
• the polymerizable composition contains a specific polymerizable compound.
• the content of the polymerizable composition in the liquid crystal composition is preferably 30 to 60% by mass, more preferably 40 to 60% by mass, and 40 to 50% by mass, assuming that the liquid crystal composition is 100% by mass. % Is particularly preferable.
• the specific polymerizable compound is a compound having a structure represented by the above formula [1A], and a compound represented by the following formula [1a] is preferable.
• X 1 and X 2 each independently represent any structure selected from the following formulas [1-a] to [1-d].
• A represents the above formula [ 1A ].
• L 2 independently represents a single bond or an alkylene group having 1 to 42 carbon atoms, and any -CH 2- of the above alkylene group is -O-, -CO-, -COO-, -OCO-, It may be replaced with -CONH-, -NHCO-, -NH-, a benzene ring or a cyclohexane ring.) (* Indicates a bond.)
• X 1 , X 2 , A, L 1 and L 2 are as defined above, but the following are preferable.
• the above formula [1-a] or the above formula [1-b] is preferable independently.
• L 1 and L 2 are each independently, preferably a single bond or an alkylene group having 1 to 30 carbon atoms, and any -CH 2- of the above alkylene group is -O-, -CO-, -COO-,-. It may be replaced with OCO-, -CONH-, -NHCO-, -NH-, a benzene ring or a cyclohexane ring. )
• the ratio of the specific polymerizable compound used is preferably 30 to 100 parts by mass in 100 parts by mass of the polymerizable composition from the viewpoint of the optical characteristics of the liquid crystal display element. More preferably, it is 40 to 95 parts by mass, and particularly preferably 40 to 80 parts by mass. Further, the specific polymerizable compound may be used alone or in combination of two or more depending on each property.
• the polymerizable composition preferably further contains one or more compounds represented by the following formula [2] (also referred to as a second specific polymerizable compound) from the viewpoint of adhesion between the liquid crystal layer and the electrode.
• Y 1 represents the following formula [2-a] or formula [2-b].
• Y 2 represents an alkylene group having 2 to 24 carbon atoms, and any-any-which is not adjacent to Y 1 or O of the above alkylene group. CH 2- may be substituted with -O-, -CO-, -COO-, -OCO-, -CONH-, -NHCO-, -NH- or -CON (CH 3 )-.
• Ym is It indicates an integer of 1 to 2.
• Yn indicates an integer of 1 to 2. However, Ym + Yn is 3.
• the plurality of Y 1 and Y 2 are independent of each other. Has the above definition.) (* Indicates a bond.)
• Specific examples of the second specific polymerizable compound include the compounds described on pages 6 to 8 of International Publication No. 2019/181882 (published on September 26, 2019).
• examples of the second specific polymerizable compound include compounds selected from the group consisting of the following formulas [2a-1] to [2a-3], and it is preferable to use these.
• Xa represents the above formula [2- a ] or formula [2-b].
• X b represents an alkylene group having 2 to 18 carbon atoms, and any -CH 2- that is not adjacent to X a or O of the above alkylene group is -O-, -CO-, -COO-, -OCO-. , -CONH-, -NHCO-, -NH- or -CON (CH 3 )-may be substituted.
• Xc indicates -COO- or -OCO- .
• X d represents an alkylene group having 2 to 12 carbon atoms.
• p1 represents an integer of 1 or 2.
• p2 represents an integer of 1 or 2. However, p1 + p2 is 3.
• p3 indicates an integer of 2 to 8.
• the plurality of X a , X b , X c , X d and p 3 have the above definitions independently of each other.
• examples of the second specific polymerizable compound include Hosmer M, Hosmer PE, Hosmer PP (all manufactured by Unichemical Co., Ltd.), light acrylate P-1A (N), and light ester P-1M (above, manufactured by Unichemical Co., Ltd.). These include Kyoeisha Chemical Co., Ltd.), KAYAMER PM-2 and KAYAMER PM-21 (manufactured by Nippon Kayaku Co., Ltd.).
• the proportion of the second specific polymerizable compound used is preferably 0.01 to 10 parts by mass in 100 parts by mass of the polymerizable composition from the viewpoint of adhesion between the liquid crystal layer and the electrode. More preferably, it is 0.01 to 5 parts by mass, and particularly preferably 0.01 to 3 parts by mass. Further, the second specific polymerizable compound may be used alone or in combination of two or more depending on each property.
• Y1 and Y2 are as described above in the above-mentioned formula [ 2 ], and Ym is The compound [2-1] which is 1 and Yn is 2, and the compound [2] in which Y1 and Y2 are as described above, Ym is 2 and Yn is 1 in the above formula [2]. -2] and may be included.
• the ratio of the compound [2-1] to the compound [2-2] can be appropriately adjusted by using, for example, the methods described in Japanese Patent Application Laid-Open No. 59-141588 and Japanese Patent Application Laid-Open No. 2007-176806. ..
• the proportion of the compound [2-1] used is 20 to 70 in 100 parts by mass of the second specific polymerizable compound represented by the above formula [2] from the viewpoint of the adhesion between the liquid crystal layer and the electrode. Parts by mass are preferred. More preferably, it is 30 to 60 parts by mass, and particularly preferably 40 to 60 parts by mass.
• the proportion of the compound [2-2] used is 20 to 70 parts by mass in 100 parts by mass of the second specific polymerizable compound represented by the above formula [2] from the viewpoint of adhesion between the liquid crystal layer and the electrode. Is preferable. More preferably, it is 30 to 60 parts by mass, and particularly preferably 40 to 60 parts by mass.
• the polymerizable composition preferably further contains one or more compounds represented by the following formula [3] (also referred to as a third specific polymerizable compound) from the viewpoint of the optical characteristics of the liquid crystal display element.
• Z 1 represents any structure selected from the following formulas [3-a] to [3-e].
• Z 2 is a single bond, -O-, -NH-, -N (CH 3 )-, -CH 2 O-, -CONH-, -NHCO-, -CON (CH 3 )-, -N (CH 3 ) CO-, -COO- or -OCO-;
• Z 3 is a single bond or-(CH) 2 ) a- (a is an integer of 1 to 15).
• Z 4 indicates a single bond, -O-, -OCH 2- , -COO- or -OCO-.
• Z 5 indicates a benzene ring or cyclohexane.
• a divalent cyclic group selected from a ring and a heterocycle, or a divalent organic group having a steroid skeleton and having 17 to 51 carbon atoms, and any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms. , May be substituted with an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms or a nitrogen atom.
• Z 6 is a single bond, —O. -, -CH 2- , -OCH 2- , -CH 2 O-, -COO- or -OCO-.
• Z 7 represents a cyclic group selected from a benzene ring, a cyclohexane ring and a heterocycle, and these cycles are represented. Any hydrogen atom on the group can be an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or fluorine. It may be substituted with an atom.
• Z8 is an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a fluorine-containing alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. It indicates a fluorine-containing alkoxy group having 1 to 18 carbon atoms.
• Zm indicates an integer of 0 to 4. When Zm is 2 or more, Zm Z 7s have the above definitions independently.) (* Indicates a bond.)
• third specific polymerizable compound examples include the compounds described on pages 8 to 21 of International Publication No. 2019/181882 (published on September 26, 2019).
• examples of the third specific polymerizable compound include the following formulas [3a-1] to [3a-2], [3a-5] to [3a-6], and [3a-9] to [ Examples thereof include compounds selected from the group consisting of 3a-10], and it is preferable to use these.
• Y a represents -O- or -COO-.
• Y b represents an alkyl group having 1 to 12 carbon atoms.
• Q1 represents an integer of 1 to 10.
• Q2 represents an integer of 1 or 2. show.
• Y c represents a single bond, -COO- or -OCO-.
• Y d represents an alkyl group or an alkoxy group having 1 to 12 carbon atoms.
• Q3 represents an integer of 1 to 10.
• Q4 represents an integer of 1 to 10. Indicates an integer of 1 or 2.) (Y e represents -O- or -COO-. Y f represents a divalent organic group having a steroid skeleton and having 17 to 51 carbon atoms. Y g represents an alkyl group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms. Indicates an alkenyl group having 2 to 18 carbon atoms. Q5 indicates an integer of 1 to 10).
• the ratio of the third specific polymerizable compound used is preferably 0.1 to 30 parts by mass in 100 parts by mass of the polymerizable composition from the viewpoint of the optical characteristics of the liquid crystal display element. More preferably, it is 0.5 to 20 parts by mass, and particularly preferably 1 to 10 parts by mass. Further, the third specific polymerizable compound may be used alone or in combination of two or more depending on each property.
• the polymerizable composition may further contain other polymerizable compounds other than the specific polymerizable compound, the second specific polymerizable compound and the third specific polymerizable compound.
• polymerizable compounds examples include 2-ethylhexyl acrylate, 1-butylethyl acrylate, 2-butoxyethyl acrylate, 2-cyanoethyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate.
• IBXA manufactured by Osaka Organic Chemical Industry Co., Ltd.
• NK Ester A-LEN-10 AM-90G, AM-130G, AMP-20GY, A-SA, S-1800A, 701A, A-200, A-400, A-600, A-1000, AB1206PE, ABE-300, A-BPE-10, A-BPE-20, A-BPE-30, A-BPE-4, A-BPEF, A- BPP-3, A-DCP, A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, APG-700, A-PTMG-65, A- 9300, A-9300-1CL, A-GLY-9E, A-GLY-20E, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, A-TMPT, AD-TMP, ATM- 35E, A-TMMT, A-9550, A-DPH,
• the polymerizable composition preferably contains a compound containing two or more thiol groups in the molecule from the viewpoint of adhesion between the liquid crystal layer and the electrode. Specifically, trimethylolpropane tris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] -isosianurate, pentaerythritol tetrakis (3-mercaptopropionate), tetraethylene glycol.
• Karenz MTPE1, BD1, NR1 and TPMB can be mentioned.
• the polymerizable composition preferably contains urethane acrylate from the viewpoint of curability of the liquid crystal layer and adhesion between the liquid crystal layer and the electrode.
• urethane acrylates include aromatic urethane acrylates and aliphatic urethane acrylates.
• aromatic urethane acrylate means a urethane acrylate having at least one aromatic group.
• aliphatic urethane acrylate means a urethane acrylate having an aliphatic group and no aromatic group.
• urethane acrylates include EBECRYL210, 220, 230, 270, 4858, 8402, 8804, 8807, 9270, 4513, 4738, 4740, 8311, 9260, 8701, 4265, 4587, 4666, 8210, 1290, 5129. 8301R, 4501, 2221, 1271, 4859, 8409, 8465, 8809, 8810, 8811, 4101, 4201, 8209, 1291, 8602, 225, KRM8911, 8667, 8296, 8200, 8904 and 8452 (above, Daisel Ornex) (Made), etc.
• the aliphatic urethane acrylates EBECRYL230, 4858, 8402, 8804, 8807, 9270, 4859, 8465, 8809 and 8811 (all manufactured by Daicel Ornex). ..
• radical initiator also referred to as a photoradical initiator
• a radical initiator that generates radicals by ultraviolet rays into the liquid crystal composition for the purpose of promoting radical polymerization of the polymerizable compound.
• photoradical initiator examples include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-Hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- ⁇ 4- [4- (2-hydroxy-2-methyl) Propionyl) -benzyl] Phenyl ⁇ -2-methylpropan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2- (dimethylamino) -2-[ (4-Methylphenyl) Methyl] -1- [4- (4-morphonyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyldiphenylphosphinoxide, bis (2,4,6-trimethylbenzoyl) Phenylphosphin
• the ratio of the photoradical initiator used is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the polymerizable composition from the viewpoint of curability of the liquid crystal layer. More preferably, it is 0.05 to 10 parts by mass. Further, the photoradical initiator can be used alone or in combination of two or more depending on the wavelength of the light source used in the curing treatment and the curability of the liquid crystal layer.
• a method for preparing a liquid crystal composition a method of mixing a liquid crystal and a polymerizable composition containing a specific polymerizable compound together, or a method in which a specific polymerizable compound and another polymerizable compound are mixed in advance with a liquid crystal is used.
• the method of mixing is mentioned.
• a method in which a specific polymerizable compound and another polymerizable compound are mixed in advance with a liquid crystal display is preferable.
• the temperature at that time is preferably less than 100 ° C.
• the substrate used for the liquid crystal display element is not particularly limited as long as it is a highly transparent substrate, and in addition to a glass substrate, an acrylic substrate, a polycarbonate substrate, a plastic substrate such as a PET (polyethylene terephthalate) substrate, and a film thereof. Can be used. In particular, when used for a dimming window or the like, a plastic substrate or a film is preferable. From the viewpoint of process simplification, it is preferable to use a substrate on which an ITO electrode for driving a liquid crystal display, an IZO (Indium Zinc Oxide) electrode, an IGZO (Indium Gallium Zinc Oxide) electrode, an organic conductive film, and the like are formed. .. Further, in the case of a reflective liquid crystal display element, if only one substrate is used, a substrate on which a metal such as a silicon wafer or aluminum or a dielectric multilayer film is formed can be used.
• the method for injecting the liquid crystal composition is not particularly limited, and examples thereof include the following methods. That is, when a glass substrate is used as the substrate, a pair of substrates is prepared, four pieces of the substrate on one side are coated with a sealant except for a part, and then the electrode surface is on the inside so that the other side is on the other side. Create an empty cell with the substrates bonded together. Then, a method of injecting the liquid crystal composition under reduced pressure from a place where the sealant is not applied to obtain a liquid crystal composition injection cell can be mentioned.
• liquid crystal display element of the present invention since the adhesion between the liquid crystal layer and the electrode is high, it is not necessary to apply a sealant to the four pieces of the substrate.
• the electrode gap (also called a gap) of the liquid crystal display element can be controlled by a spacer or the like.
• the method include a method of introducing a spacer of a desired size into the liquid crystal composition, a method of using a substrate having a column spacer of the desired size, and the like. Further, when a plastic or film substrate is used as the substrate and the substrates are laminated by laminating, the gap can be controlled without introducing a spacer.
• the size of the gap of the liquid crystal display element is preferably 1 to 100 ⁇ m. More preferably, it is 1 to 50 ⁇ m, and particularly preferably 2 to 30 ⁇ m. If the gap is too small, the contrast of the liquid crystal display element will decrease, and if it is too large, the drive voltage of the element will increase.
• the liquid crystal display element is obtained by curing the liquid crystal composition to form a liquid crystal layer.
• the curing of the liquid crystal composition is preferably carried out by irradiating the liquid crystal composition injection cell with ultraviolet rays.
• the light source of the ultraviolet irradiation device used at that time include a metal halide lamp and a high-pressure mercury lamp.
• the wavelength of ultraviolet rays is preferably 250 to 400 nm. Of these, 310 to 370 nm is preferable.
• the irradiation light intensity of ultraviolet rays can be appropriately determined by experiments or the like, and the end point thereof may be determined by the concentration of the unreacted polymerizable compound in the liquid crystal composition or the like.
• the irradiation light intensity of ultraviolet rays is preferably 0.1 mW / cm 2 or more, and the irradiation light intensity may be higher than 1 mW / cm 2 in order to complete the polymerization of the polymerizable compound. .. Further, while the ultraviolet rays are irradiated, the voltage may be applied between the electrodes or the voltage may not be applied between the electrodes.
• heat treatment may be performed.
• the temperature at that time is preferably 20 to 120 ° C. More preferably, it is 30 to 100 ° C.
• Preparation of liquid crystal composition ⁇ Preparation of liquid crystal composition (1)> S1 (3.0 g), R1 (1.5 g), R2 (0.2 g) and R5 (0.3 g) were mixed and stirred at 25 ° C. for 6 hours to prepare a solution of the polymerizable composition. Then, a solution (5.0 g), P1 (0.25 g) and L1 (7.5 g) of this polymerizable composition were mixed and stirred at 25 ° C. for 8 hours to obtain a liquid crystal composition (1).
• a metal halide lamp having an illuminance of 10 mW / cm 2 was used for the liquid crystal display element before this treatment to cut wavelengths of 350 nm or less, and ultraviolet irradiation was performed with an irradiation time of 60 seconds. As a result, a liquid crystal display element (glass substrate) was obtained.
• the liquid crystal display element before this treatment was irradiated with ultraviolet rays by the same method as in the above-mentioned "Manufacturing of liquid crystal display element (glass substrate)" to obtain a liquid crystal display element (plastic substrate).
• Table 1 summarizes the measurement results of Haze at the initial stage, after storage in a constant temperature and humidity chamber (constant temperature and humidity), and after irradiation with ultraviolet rays (ultraviolet rays).
• the liquid crystal display element (glass substrate and plastic substrate) is stored in a constant temperature and humidity chamber with a temperature of 80 ° C. and a humidity of 90% RH for 24 hours, and the peeling of the liquid crystal display element and the presence or absence of air bubbles are confirmed.
• As a stability test of the liquid crystal display element in a high temperature and high humidity environment Specifically, those in which the element is not peeled off (the liquid crystal layer and the resin film or the resin film and the electrode are peeled off) and those in which bubbles are not generated in the device are excellent in this evaluation. (Good display in the table).
• Table 2 summarizes the results (adhesion) of the adhesion between the liquid crystal layer and the electrode after initial storage in a constant temperature and humidity chamber (constant temperature and humidity) and after irradiation with ultraviolet rays (ultraviolet rays).
• Example 1 ⁇ Examples 1 to 8, Comparative Example 1 and Comparative Example 2> As shown in Tables 1 and 2 below, using the liquid crystal compositions (1) to (8), a liquid crystal display element is manufactured by the above method, evaluation of optical characteristics (scattering characteristics and transparency), and liquid crystal. The adhesion between the layer and the electrode was evaluated. At that time, in Example 1, Example 3, Example 8 and Comparative Example 1, a liquid crystal display element was manufactured and each evaluation was performed using a glass substrate, and Example 2, Example 4, Example 5, and Example 1 were carried out. 6. In Example 7 and Comparative Example 2, a plastic substrate was used.
• the liquid crystal display element of the example has good optical characteristics, that is, the change in Haze after storage in the constant temperature and humidity chamber and after irradiation with ultraviolet rays is smaller than that of the comparative example. Further, the liquid crystal display element has a high adhesion between the liquid crystal layer and the electrode, and even after being exposed to these harsh environments, no peeling or air bubbles were observed in the liquid crystal display element. In particular, even if a plastic substrate is used as the substrate of the liquid crystal display element, these characteristics are good. Specifically, in the comparison under the same conditions, the comparison between Example 1 and Comparative Example 1 and the comparison between Example 2 and Comparative Example 2 are performed.
• the second specific polymerizable compound was used in the polymerizable composition in addition to the specific polymerizable compound, the constant temperature and humidity bath for a long time performed in the emphasis test was performed as compared with the case where the second specific polymerizable compound was not used. Even after being stored in the liquid crystal display element, there were few bubbles generated in the liquid crystal display element. Specifically, it is a comparison between Example 4 and Example 5 in the comparison under the same conditions. Further, when the third specific polymerizable compound is used in the polymerizable composition in addition to the specific polymerizable compound, the Haze in the voltage-applied state is lower than that in the case where the third specific polymerizable compound is not used, and the haze is lower. , The drive voltage is also lower.
• Example 5 and Example 6 were compared, and in Example 6, Haze was lower at an applied voltage lower than that of Example 5.
• urethane acrylate is used in the polymerizable composition in addition to the specific polymerizable compound, it is stored in a constant temperature and humidity chamber for a long time in the emphasis test as compared with the case where it is not used. However, no bubbles were generated in the liquid crystal display element. Specifically, it is a comparison between Example 5 and Example 7 in the comparison under the same conditions.
• liquid crystal display element of the present invention can be suitably used for a normal type element that is in a scattered state when no voltage is applied and is in a transparent state when a voltage is applied.
• This element can be used for a liquid crystal display for display purposes, a dimming window for controlling light blocking and transmission, an optical shutter element, and the like, and the substrate of this normal type element is made of plastic.
• a substrate can be used.

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