Liquid crystal element, liquid crystal aligning agent for forming weak anchoring film, and method for producing liquid crystal element

Abstract

To provide a liquid crystal element that allows low-voltage driving while retaining superior liquid crystal alignment, exhibits reduced afterimage, and ensures enhanced adhesion between a liquid crystal alignment film and a sealing material.SOLUTION: A liquid crystal element 10 includes a pair of substrates consisting of a first substrate 11 and a second substrate 12, and a liquid crystal layer 13 incorporating liquid crystal molecules 25. One of the first substrate 11 and the second substrate 12 is provided with a weak anchoring liquid crystal alignment film 23, while the other is provided with a strong anchoring liquid crystal alignment film 22 that has anchoring energy stronger than that of the weak anchoring liquid crystal alignment film 23. The weak anchoring liquid crystal alignment film 23 is produced with a liquid crystal alignment agent containing polyorganosiloxane.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal element, a liquid crystal aligning agent for forming a weak anchoring film, and a method for producing a liquid crystal element. [Background technology]

[0002] In liquid crystal devices, the initial alignment of liquid crystal molecules is generally determined by the anchoring of the liquid crystal molecules by a liquid crystal alignment film. Recently, various liquid crystal devices have been proposed for horizontal alignment modes, such as IPS and FFS modes, in which a liquid crystal alignment film with strong anchoring energy (hereinafter also referred to as a "strong anchoring liquid crystal alignment film") is formed on one of a pair of substrates, and a liquid crystal alignment film with no or very low anchoring energy (hereinafter also referred to as a "weak anchoring liquid crystal alignment film") is formed on the other substrate. Liquid crystal devices utilizing the weak anchoring state are expected to achieve further improvements, such as improved brightness and contrast ratio, low-voltage operation, and fast response (fast rise time), compared to conventional liquid crystal devices in which strong anchoring liquid crystal alignment films are formed on both substrates. "Weak anchoring" is also known as "zero-plane anchoring."

[0003] For example, Patent Document 1 discloses a method for manufacturing a liquid crystal cell by forming a zero-plane anchoring film on a first substrate using a method including a step of contacting a liquid crystal composition containing liquid crystal and a radically polymerizable compound with a radical-generating film and applying sufficient energy to polymerize the radically polymerizable compound, and then forming a liquid crystal alignment film on a second substrate using a known liquid crystal alignment agent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 004433 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, the preparation of a weak anchoring liquid crystal alignment film requires a step of contacting a liquid crystal composition containing liquid crystal and a radical polymerizable compound with a radical generating film formed on a first substrate, and applying sufficient energy to cause a polymerization reaction of the radical polymerizable compound in this state. From the viewpoint of productivity, it is desirable to have a liquid crystal element that can prepare a weak anchoring liquid crystal alignment film by a simple procedure, yet can achieve low-voltage driving due to the weak anchoring state, and also exhibit good liquid crystal alignment properties.

[0006] For example, narrower bezels are being developed for mobile applications such as smartphones and tablet PCs, as well as for large-screen TVs and PC monitors, from the perspective of design and miniaturization of display devices. One known method for achieving narrower bezels is to form a liquid crystal alignment film over the entire surface of the substrate, then apply a sealant to the liquid crystal alignment film and bond the substrates together. However, placing a sealant on the liquid crystal alignment film can easily reduce the adhesion between the substrates, raising concerns that the substrates may be more susceptible to peeling due to external forces, etc.

[0007] Furthermore, as the applications of liquid crystal elements become more diverse, there is a demand for further improving the quality of liquid crystal elements by minimizing the occurrence of image retention in the liquid crystal elements. However, it is difficult to simultaneously satisfy these multiple characteristics, and there is room for further improvement in liquid crystal aligning agents and liquid crystal elements.

[0008] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a liquid crystal element that can be driven at a low voltage while maintaining excellent liquid crystal alignment, has little image retention, and has excellent adhesion between the liquid crystal alignment film and the sealing material. Another object is to provide a liquid crystal aligning agent for forming a weak anchoring film, which can be used to obtain a liquid crystal element that can be driven at a low voltage while maintaining excellent liquid crystal alignment, has little image retention, and has excellent adhesion between the liquid crystal alignment film and the sealing material. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a liquid crystal element comprising a pair of substrates consisting of a first substrate and a second substrate, and a liquid crystal layer containing liquid crystal molecules, wherein a weak anchoring liquid crystal alignment film is formed on one of the first substrate and the second substrate, and a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film is formed on the other substrate, and the weak anchoring liquid crystal alignment film is formed from a liquid crystal alignment agent containing polyorganosiloxane.

[0010] According to another aspect of the present invention, there is provided a liquid crystal aligning agent for forming a weak anchoring film, which is used to form a weak anchoring liquid crystal alignment film, and contains polyorganosiloxane.

[0011] In addition, according to another aspect of the present invention, there is provided a method for manufacturing a liquid crystal element, which includes the steps of forming a weak anchoring liquid crystal alignment film on one of a pair of substrates using the above-mentioned liquid crystal alignment agent for forming a weak anchoring film, and forming a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film on the other substrate. [Effects of the Invention]

[0012] According to the present invention, a liquid crystal element can be obtained that can be driven at a low voltage while maintaining excellent liquid crystal alignment properties, has little image retention, and has excellent adhesion between the liquid crystal alignment film and the sealing material. Also, a liquid crystal aligning agent for forming a weak anchoring film can be obtained that can be driven at a low voltage while maintaining excellent liquid crystal alignment properties, has little image retention, and has excellent adhesion between the liquid crystal alignment film and the sealing material. [Brief explanation of the drawings]

[0013] [Figure 1] Schematic diagram of an FFS type liquid crystal element. [Figure 2]Schematic plan views of the top electrode used in the manufacture of a liquid crystal display element, where (a) is a top view of the top electrode and (b) is an enlarged partial view of the top electrode. [Figure 3] FIG. 1 shows four drive electrodes. DETAILED DESCRIPTION OF THE INVENTION

[0014] Matters related to the embodiments will be explained in detail below. In this specification, a numerical range described using "to" means that the numerical values ​​before and after "to" are included as the lower and upper limits. A "structural unit" refers to a unit that mainly constitutes the main chain structure, and at least two or more units are contained in the main chain structure. A structural unit is typically a repeating unit constructed based on one monomer. In addition, a structural unit may be obtained by reacting a repeating unit having a reactive group with a compound having a functional group that can react with the reactive group.

[0015] As used herein, the term "hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The term "chain hydrocarbon group" refers to a linear hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure and is composed solely of a chain structure. However, the chain hydrocarbon group may be saturated or unsaturated. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. However, the alicyclic hydrocarbon group does not necessarily have to be composed solely of an alicyclic hydrocarbon structure, and may also contain a chain structure as part of it. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. However, the aromatic hydrocarbon group does not necessarily have to be composed solely of an aromatic ring structure, and may contain a chain structure or an alicyclic hydrocarbon structure as part of it. The term "organic group" refers to an atomic group obtained by removing any hydrogen atom from a carbon-containing compound (i.e., an organic compound).

[0016] The "main chain" of a polymer refers to the "backbone" portion of the polymer, which is the longest chain of atoms. It is acceptable for this "backbone" portion to contain a ring structure. For example, "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. A "side chain" refers to a portion branched from the "backbone" portion of the polymer. "(Meth)acrylic" is a term that encompasses acrylic and methacrylic, and "(meth)acrylo" is a term that encompasses acrylo and methacrylo. "(Meth)acrylate" is a term that encompasses acrylate and methacrylate. "Epoxy group" is a term that encompasses oxiranyl and oxetanyl groups.

[0017] Liquid crystal element An embodiment in which the liquid crystal element of the present disclosure is embodied as an FFS (Fringe Field Switching) type liquid crystal element will be described below with reference to the drawings as appropriate.

[0018] An FFS type liquid crystal element, which is one type of in-plane switching liquid crystal element, controls light transmission by applying a fringe electric field to homogeneously aligned liquid crystal molecules. As shown in Fig. 1, a liquid crystal element 10 includes a pair of substrates consisting of a first substrate 11 and a second substrate 12, and a liquid crystal layer 13 disposed between the pair of substrates and containing liquid crystal molecules 25.

[0019] The first substrate 11 and the second substrate 12 are transparent substrates made of glass or resin films. Examples of resins that can be used to make the substrates include various materials such as silicon, polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polypropylene, polyvinyl chloride, aromatic polyamide, polyamideimide, polyimide, triacetyl cellulose (TAC), and polymethyl methacrylate.

[0020] Scanning lines, common lines, and signal lines (not shown) are provided on the surface of the first base material 11, and a common electrode 14, which is a surface electrode connected to the common line, is provided in an area partitioned by the scanning lines and common lines. Furthermore, comb-shaped pixel electrodes 16 are disposed on the common electrode 14 of the first substrate 11 with an insulating film 15 interposed therebetween. The common electrode 14 and pixel electrode 16 form an electrode pair. The common electrode 14 and pixel electrode 16 are, for example, a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO), an ITO film made of indium oxide-tin oxide (InO-SnO), or a transparent conductive film made of a carbon material. TFTs (not shown) serving as switching elements are disposed near the intersections of the scanning lines and signal lines, and application and release of voltage to the common electrode 14 and pixel electrode 16 is controlled by driving the TFTs.

[0021] A liquid crystal alignment film 21 is formed on the surfaces of the pixel electrodes 16 on the first substrate 11 and the slits 19 between the pixel electrodes 16. The liquid crystal alignment film 21 is a strong anchoring liquid crystal alignment film. Here, a "strong anchoring liquid crystal alignment film" refers to a film that can uniaxially align liquid crystal molecules near the liquid crystal alignment film when an electric field is applied. In this embodiment, the liquid crystal alignment film 21 is formed using a liquid crystal alignment agent for horizontal alignment, which can form a state in which the slow axes of the liquid crystal molecules 25 are aligned approximately parallel to the substrate surface when no voltage is applied between the electrodes. Here, "horizontal alignment" refers to a state in which the slow axes of the liquid crystal molecules 25 are aligned approximately parallel to the substrate surface. Therefore, the concept of horizontal alignment also includes a case in which the slow axes of the liquid crystal molecules 25 are slightly tilted (preferably less than 10°) with respect to the substrate surface. Note that a state in which the slow axes of the liquid crystal molecules 25 are aligned approximately perpendicular to the substrate surface is called "vertical alignment."

[0022] The liquid crystal alignment film 21 may be a film formed from a liquid crystal alignment agent that has not been subjected to alignment treatment such as rubbing or photo-alignment treatment, but it is preferable that it is a rubbed alignment film formed from a liquid crystal alignment agent that has been subjected to rubbing treatment, or a photo-alignment film formed from a liquid crystal alignment agent that has been subjected to photo-alignment treatment.

[0023] A color filter 17 and an overcoat film 18 are provided on the surface of the second substrate 12. A liquid crystal alignment film 22 is formed on the surface of the overcoat film 18 of the second substrate 12. The liquid crystal alignment film 22 is a weak anchoring liquid crystal alignment film. Here, a "weak anchoring liquid crystal alignment film" is a film that has no in-plane alignment constraint for the liquid crystal molecules 25, or even if it does, the in-plane alignment constraint is weaker than the intermolecular force between the liquid crystal molecules. Therefore, in the weak anchoring state, the in-plane alignment direction can be freely rotated 360° by controlling an external field such as an electric field or a magnetic field. It is preferable that the liquid crystal alignment film 22 is a film that has not been subjected to an alignment treatment.

[0024] The first substrate 11 and the second substrate 12 are arranged with a predetermined gap (cell gap) between them via a spacer (not shown). Examples of the spacer include columnar spacers and bead spacers. The first substrate 11 and the second substrate 12 are bonded together at their peripheries via a sealant. A liquid crystal composition is filled into the space surrounded by the first substrate 11, the second substrate 12, and the sealant, thereby forming a liquid crystal layer 13.

[0025] The "weak anchoring liquid crystal alignment film" and the "strong anchoring liquid crystal alignment film" will be explained in more detail. The difference between the "weak anchoring liquid crystal alignment film" and the "strong anchoring liquid crystal alignment film" is the difference in the alignment constraint force that constrains the alignment direction of the liquid crystal molecules. That is, the alignment constraint force of the weak anchoring liquid crystal alignment film is substantially zero in the in-plane direction, whereas the strong anchoring liquid crystal alignment film has stronger anchoring energy than the weak anchoring liquid crystal alignment film.

[0026] More specifically, in a liquid crystal cell, when the orientation of liquid crystal molecules near the alignment film is controlled by a strong anchoring liquid crystal alignment film, when an electric field is applied, the liquid crystal molecules at the interface between the liquid crystal layer and the liquid crystal alignment film maintain their alignment direction before the application of the electric field, while still subject to the alignment constraint force of the liquid crystal alignment film. In contrast, a weak anchoring liquid crystal alignment film has no or very weak alignment constraint force on the liquid crystal molecules at the interface between the liquid crystal layer and the liquid crystal alignment film, making the alignment direction of the liquid crystal molecules prone to change when an electric field is applied. Weak anchoring of the liquid crystal alignment film reduces the alignment constraint force on the liquid crystal molecules not only in the horizontal direction but also in the vertical direction. Therefore, a liquid crystal cell equipped with a weak anchoring liquid crystal alignment film is thought to be able to drive liquid crystal molecules at a lower voltage.

[0027] In a normal liquid crystal element, the alignment of liquid crystal molecules is controlled by a pair of liquid crystal alignment films (strong anchoring liquid crystal alignment films), but the alignment of liquid crystal molecules can also be controlled by combining a weak anchoring liquid crystal alignment film and a strong anchoring liquid crystal alignment film, as in the liquid crystal element 10. For example, as shown in Figure 1, if a strong anchoring liquid crystal alignment film is formed on the first substrate 11 (electrode substrate) side on which a pair of electrodes is provided, using a liquid crystal alignment agent for horizontal alignment, and a weak anchoring liquid crystal alignment film is formed on the second substrate 12 (counter substrate) side, then when the liquid crystal element is not driven, a state in which liquid crystal molecules 25 are horizontally aligned is formed throughout the entire liquid crystal layer.

[0028] Polarizing plates 23 and 24 are disposed on the outer sides of the first substrate 11 and the second substrate 12, respectively. A terminal area is provided on the outer edge of the first substrate 11, and a driver IC or the like for driving the liquid crystal is connected to the terminal area to drive the liquid crystal element 10. In detail, when a voltage is applied to the electrode pair to form an electric field (fringe field) between the common electrode 14 and the pixel electrode 16, the electric field is directed toward the common electrode 14 on both sides of the pixel electrode 16, causing not only the liquid crystal molecules present between the pixel electrodes but also the liquid crystal molecules on the pixel electrodes to rotate. Therefore, the FFS-type liquid crystal element has the advantage of being able to achieve a wider viewing angle and higher contrast.

[0029] Although the liquid crystal element of the present disclosure has been described as an FFS-type liquid crystal element, the driving method of the liquid crystal element of the present disclosure is not limited to the FFS-type. For example, the liquid crystal element can be applied to various modes such as TN (Twisted Nematic) type, STN (Super-Twisted Nematic) type, VA (Vertical Alignment) type (including VA-MVA type, VA-PVA type, etc.), IPS (In-Plane Switching) type, OCB (Optically Compensated Bend) type, PSA (Polymer Sustained Alignment) type, and ECB (Electrically Controlled Birefringence) type. Among these, horizontal alignment type liquid crystal elements such as IPS type and FFS type are preferred.

[0030] <Liquid crystal alignment agent for forming weak anchoring film> Next, we will explain the liquid crystal aligning agent for forming a weak anchoring film of the present disclosure (hereinafter simply referred to as "liquid crystal aligning agent") used to form a weak anchoring liquid crystal alignment film. The liquid crystal aligning agent of the present disclosure contains polyorganosiloxane as a polymer component. Unless otherwise specified, each component may be used alone or in combination of two or more.

[0031] <Polyorganosiloxane> The polyorganosiloxane (hereinafter also referred to as "polyorganosiloxane (PS)") contained in the liquid crystal aligning agent of the present disclosure is a polymer having a siloxane bond in its main skeleton. Examples of polyorganosiloxane (PS) include hydrolysis condensates obtained by hydrolyzing a hydrolyzable silane compound (for example, an alkoxysilane compound). As long as the polyorganosiloxane (PS) contains two or more structural units having a siloxane bond in its main chain, it may be an oligomer having, for example, about 3 to 20 repeating units, or it may be a polymer having a higher molecular weight than an oligomer.

[0032] The structure of polyorganosiloxane (PS) is not particularly limited, and examples thereof include polyorganosiloxanes having a random structure, ladder structure, cage structure, incomplete cage structure, cyclic structure, etc. Among these, it is preferable that the polyorganosiloxane (PS) has at least one of a cage structure, an incomplete cage structure, and a cyclic structure, in order to obtain a film that can sufficiently achieve low-voltage driving of a liquid crystal element while maintaining good liquid crystal alignment. Note that the structure of polyorganosiloxane is 29 It can be identified by Si-NMR measurement and molecular weight measurement.

[0033] The polyorganosiloxane (PS) may have a side chain. Examples of the side chain that the polyorganosiloxane (PS) has include monovalent organic groups having 1 to 30 carbon atoms. Specifically, the side chain includes monovalent hydrocarbon groups having 1 to 30 carbon atoms, monovalent hydrocarbon groups having 1 to 30 carbon atoms and having a substituent, and monovalent hydrocarbon groups having 2 to 30 carbon atoms in which any methylene group is -O-, -S-, -CO-, -COO-, -OCO-, -NR 10 -, -NR 10 -CO-, -CO-NR 10 -, -O-CO-NR 10 -, -NR 10 -CO-O- or -NR 10 -CO-NR 11 -, and groups in which any hydrogen atom in the group has been replaced by a substituent. 10 and R 11 are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0034] Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms include a linear or branched monovalent saturated hydrocarbon group having 1 to 30 carbon atoms, a linear or branched monovalent unsaturated hydrocarbon group having 2 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0035] Specific examples of the linear or branched monovalent saturated hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Specific examples of the linear or branched unsaturated hydrocarbon group having 2 to 30 carbon atoms include alkenyl groups such as ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, and 2-butenyl; and alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, and 2-butynyl.

[0036] Examples of the monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms include aliphatic hydrocarbon groups having a 3 to 30 carbon atom alicyclic monocyclic hydrocarbon structure or a 6 to 30 carbon atom alicyclic polycyclic hydrocarbon structure as a ring structure. The 3 to 30 carbon atom alicyclic monocyclic hydrocarbon structure and the 6 to 30 carbon atom alicyclic polycyclic hydrocarbon structure may be saturated or unsaturated. Specific examples of the ring contained in the alicyclic hydrocarbon group include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclodecene ring, a norbornane ring, a bicyclo[2.2.2]octane ring, and an adamantane ring. The monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms in the side chain of the polyorganosiloxane (PS) may have only one aliphatic hydrocarbon ring or two or more aliphatic hydrocarbon rings.

[0037] Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include hydrocarbon groups having an aromatic monocyclic hydrocarbon structure having 6 to 30 carbon atoms or an aromatic polycyclic hydrocarbon structure having 6 to 30 carbon atoms as a ring structure. Specific examples of the ring contained in the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, an indene ring, and a fluorene ring. The monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms contained in the side chain of the polyorganosiloxane (PS) may have only one ring (aromatic hydrocarbon ring and aliphatic hydrocarbon ring in total) or two or more rings.

[0038] When the side chain of the polyorganosiloxane (PS) has a substituent, examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a hydroxyl group, a cyano group, a nitro group, a carboxy group, and an amino group.

[0039] The side chain of polyorganosiloxane (PS) may be a liquid crystal aligning group or a photoaligning group. Here, in this specification, the term "liquid crystal aligning group" refers to a group that can impart liquid crystal aligning ability to a film without light irradiation. Specific examples of the liquid crystal aligning group include an alkyl group having 4 to 30 carbon atoms, an alkoxy group having 4 to 30 carbon atoms, a fluoroalkyl group having 4 to 30 carbon atoms, a fluoroalkoxy group having 4 to 30 carbon atoms, a polyalkyleneoxy group having 4 to 30 carbon atoms, a group having a mesogen structure in which two or more rings (preferably at least one ring selected from the group consisting of a cyclohexane ring, a benzene ring, and a naphthalene ring) are bonded directly or via a divalent linking group (for example, the heteroatom-containing group described above), and a group having a steroid skeleton.

[0040] The photo-alignable group refers to a group that can impart anisotropy to a film by photoreactions such as photoisomerization, photodimerization, photo-Fries rearrangement, or photodecomposition caused by light irradiation. Specific examples of the photo-alignable group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, a stilbene-containing group containing stilbene or a derivative thereof as a basic skeleton, and a phenylbenzoate-containing group containing phenylbenzoate or a derivative thereof as a basic skeleton.

[0041] When polyorganosiloxane (PS) has a monovalent organic group having 1 to 30 carbon atoms in the side chain, it is preferable that a liquid crystal alignment film exhibiting excellent liquid crystal alignment properties can be formed while sufficiently achieving low-voltage driving of the liquid crystal device. In terms of further enhancing the effect of expressing the weak anchoring property of the film, polyorganosiloxane (PS) has an alkyl group having 1 to 30 carbon atoms, "*-R 2 -(OR 3 ) r -OR 4 " (wherein R 2 and R 3 are each independently an alkanediyl group, r is an integer of 0 or more, and R 4 is an alkyl group when r is 0, and is a hydrogen atom or an alkyl group when r is 1 or more. The same applies hereinafter.) or a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring (hereinafter, these are also referred to as "specific groups" inclusively) on the side chain.

[0042] Here, the term "having a specific group in the side chain" means an alkyl group having 1 to 30 carbon atoms, such as "*-R 2 -(OR 3 ) r -OR 4" or a monovalent alicyclic hydrocarbon group having 2 to 30 carbon atoms and having one aliphatic hydrocarbon ring, is bonded to an atom (preferably a silicon atom) constituting the main chain of the polyorganosiloxane, either directly or via a divalent linking group. Examples of the divalent linking group include the above-mentioned heteroatom-containing groups, groups in which a methylene group in a divalent aliphatic hydrocarbon group having 2 to 10 carbon atoms is replaced with the above-mentioned heteroatom-containing group, and groups in which any hydrogen atom of the above group is substituted. Examples of the substituent include a halogen atom and a hydroxyl group.

[0043] The alkyl group having 1 to 30 carbon atoms may be linear or branched. Specific examples of the alkyl group having 1 to 30 carbon atoms include the groups exemplified as the linear or branched saturated hydrocarbon group having 1 to 30 carbon atoms. The alkyl group that the polyorganosiloxane (PS) has on its side chain preferably has 3 or more carbon atoms, more preferably has 4 or more carbon atoms, and even more preferably has 5 or more carbon atoms. Furthermore, from the viewpoint of preventing the pretilt angle of liquid crystal molecules in the vicinity of the weak anchoring liquid crystal alignment film from becoming too high, the alkyl group that the polyorganosiloxane (PS) has on its side chain preferably has 25 or less carbon atoms, more preferably has 20 or less carbon atoms, and even more preferably has 17 or less carbon atoms.

[0044] With regard to the alkyl group that the polyorganosiloxane (PS) has on its side chain, more specifically, when the alkyl group is linear, the number of carbon atoms in the linear alkyl group is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. The number of carbon atoms in the linear alkyl group is preferably 20 or less, more preferably 17 or less, even more preferably 15 or less, and even more preferably 11 or less.

[0045] When the alkyl group in the side chain of the polyorganosiloxane (PS) is branched, the carbon number of the longest portion of the branched alkyl group is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. The carbon number of the longest portion of the branched alkyl group is preferably 20 or less, more preferably 17 or less, even more preferably 15 or less, and even more preferably 11 or less. For example, when a 1-hexylnonyl group is introduced into the side chain of the polyorganosiloxane, the carbon number of the longest portion of the 1-hexylnonyl group is 9.

[0046] "*-R 2 -(OR 3 ) r -OR 4 Examples of the group having 2 to 30 carbon atoms represented by " include an alkoxyalkyl group having 2 to 30 carbon atoms and a polyalkyleneoxy group having 3 to 30 carbon atoms. Of these, a specific example of an alkoxyalkyl group having 2 to 30 carbon atoms is a group in which one methylene group in an alkyl group having 3 to 30 carbon atoms is replaced with -O-. In addition, in the case of a polyalkyleneoxy group having 3 to 30 carbon atoms (i.e., when r is 1 or more), R 2 or R 3 R may be linear or branched. 4 The polyalkyleneoxy group may be linear or branched, but is preferably linear. Specific examples of the polyalkyleneoxy group include a group having a polyethylene oxide structure, a group having a polypropylene oxide structure, and a group having a polyethylene oxide structure and a polypropylene oxide structure.

[0047] The monovalent alicyclic hydrocarbon group having one aliphatic hydrocarbon ring and 3 to 30 carbon atoms may be a group having a saturated chain hydrocarbon ring having 3 to 12 carbon atoms as the aliphatic hydrocarbon ring. Examples of the aliphatic hydrocarbon ring include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, and a cyclodecane ring. To reduce the anchoring force of liquid crystals, an aliphatic hydrocarbon ring other than a cyclohexane ring is preferred, an aliphatic hydrocarbon ring having 7 or more ring members is more preferred, and an aliphatic hydrocarbon ring having 7 to 12 ring members is even more preferred. The monovalent alicyclic hydrocarbon group may have a substituent on the ring moiety. Examples of the substituent include a methyl group, an ethyl group, a propyl group, and a halogen atom.

[0048] In order to further enhance the effect of low-voltage driving, the side chains of the polyorganosiloxane (PS) preferably contain at least one of an alkyl group having 1 to 30 carbon atoms and a group having a saturated chain hydrocarbon ring having 7 to 12 carbon atoms, more preferably an alkyl group having 3 or more carbon atoms, and even more preferably an alkyl group having 5 or more carbon atoms.

[0049] On the other hand, from the viewpoint of suppressing an increase in the pretilt angle of liquid crystal molecules present in the vicinity of a film formed using polyorganosiloxane (PS) and enhancing the effect of expressing weak anchoring properties, it is preferable that the polyorganosiloxane (PS) does not have one or more of the partial structures of a photoalignment group, a benzene ring, and two or more cyclohexane rings bonded by a single bond, -COO-, or -NR- (wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), more preferably does not have two or more of them, and even more preferably does not have all three of them.

[0050] Specifically, a preferred embodiment of the polyorganosiloxane (PS) is a polymer containing a structural unit represented by the following formula (S-1). [ka] (In formula (S-1), R 1 is an alkyl group having 1 to 30 carbon atoms, "*-R 2 -(OR 3 ) r -OR 4 " and a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring, which is bonded to a silicon atom via a single bond or a divalent linking group. R 2 and R 3 are each independently an alkanediyl group. r is an integer of 0 or greater. 4 is an alkyl group when r is 0, and is a hydrogen atom or an alkyl group when r is 1 or more.

[0051] In the above formula (S-1), R 1 Specific and preferred examples of include the same groups as those explained as specific preferred examples of the groups that polyorganosiloxane (PS) has on its side chain.

[0052] Regarding polyorganosiloxane (PS), the structural unit represented by the above formula (S-1) 29 The integral ratio of the peak in the Si-NMR spectrum is preferably 70 to 99%, more preferably 80 to 99%, and even more preferably 90 to 99%. 29 The integral ratio of the peaks in the Si-NMR spectrum is a value that indicates the content of the structural unit represented by the above formula (S-1) in the polyorganosiloxane. The larger this value, the higher the content of the structural unit represented by the above formula (S-1).

[0053] Another preferred embodiment of the polyorganosiloxane (PS) is a cyclic polysiloxane having a molecular weight of not more than 1,500. The cyclic polysiloxane as the polyorganosiloxane (PS) is represented, for example, by the following formula (S-3). [ka] (In formula (S-3), R 11 ~R16 are each independently a hydrogen atom or a monovalent organic group, provided that R 11 ~R 16 At least one of the groups is an alkyl group having 1 to 30 carbon atoms, 2 -(OR 3 ) r -OR 4 " and a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring, which is bonded to a silicon atom via a single bond or a divalent linking group. R 2 , R 3 , R 4 and r have the same meaning as in the formula (S-1). n is an integer of 1 to 18. When n is 2 or more, multiple R 11 are the same or different, and multiple R 2 are the same or different.)

[0054] As the polyorganosiloxane (PS), a reaction product of a polyorganosiloxane having an epoxy group (hereinafter also referred to as "reactive polyorganosiloxane") and a carboxylic acid having a specific group (hereinafter also referred to as "specific aliphatic carboxylic acid") can be preferably used. The reactive polyorganosiloxane preferably has at least one of a cage structure, an incomplete cage structure, and a cyclic structure. Specifically, the reactive polyorganosiloxane is preferably a polyorganosiloxane containing a structural unit represented by the following formula (S-2), or a cyclic polysiloxane having an epoxy group. [ka] (In formula (S-2), Y 1 is a monovalent group having an epoxy group.

[0055] In the above formula (S-2), Y 1Examples of the monovalent group represented by the formula (1) include groups having a glycidyl group or a 3,4-epoxycyclohexyl group. Specific examples include a glycidyloxymethyl group, a 2-glycidyloxyethyl group, a 3-glycidyloxypropyl group, a 4-glycidyloxybutyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(3,4-epoxycyclohexyl)propyl group, and a 4-(3,4-epoxycyclohexyl)butyl group.

[0056] An example of a cyclic polysiloxane having an epoxy group is a compound represented by the following formula (S-4). [ka] (In formula (S-4), Y 11 ~Y 16 are each independently a hydrogen atom or a monovalent organic group. 11 ~Y 16 At least one of the Y is a monovalent group having an epoxy group. n is an integer of 1 to 18. When n is 2 or more, multiple Y 11 are the same or different, and multiple Y 2 are the same or different.)

[0057] In the above formula (S-4), Y 11 ~Y 16 When Y is a monovalent group having an epoxy group, specific examples thereof include groups having a glycidyl group or a 3,4-epoxycyclohexyl group. 1 Examples of the monovalent group represented by the following formula include the same groups as those exemplified above.

[0058] Specific examples of cyclic polysiloxanes having epoxy groups include compounds represented by the following formulas (A-1) to (A-5). Commercially available cyclic polysiloxanes having epoxy groups can also be used. Examples of commercially available products include CS-697 and CS-783 (manufactured by Sigma-Aldrich), KR-470, X-40-2670, and X-40-2678 (manufactured by Shin-Etsu Silicones). [ka] (In formulas (A-1) to (A-5), m is an integer of 0 to 17.)

[0059] The specific aliphatic carboxylic acid is an alkyl group having 1 to 30 carbon atoms, such as "*-R 2 -(OR 3 ) r -OR 4 " or a compound in which each of the groups exemplified as a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring is bonded to a carboxy group. The specific aliphatic carboxylic acid preferably has an alkyl group having 1 to 30 carbon atoms, an alkoxyalkyl group having 2 to 30 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring, in order to achieve a higher level of both liquid crystal alignment properties and low-voltage drive, and more preferably an aliphatic carboxylic acid having an alkyl group having 1 to 30 carbon atoms. Specific examples and preferred examples of the alkyl group having 1 to 30 carbon atoms that the aliphatic carboxylic acid has are the same as those explained above.

[0060] <Synthesis of Polyorganosiloxane> There are no particular limitations on the method for synthesizing polyorganosiloxane (PS). For example, polyorganosiloxane (PS) can be obtained by using a compound having an alkoxysilyl group (hereinafter also referred to as an "alkoxysilane compound") as a raw material and carrying out a hydrolysis-condensation reaction of the alkoxysilane compound. Specific examples include the following methods [1s] and [2s].

[0061] [1s] A method in which a hydrolyzable silane compound (ms-1) having an epoxy group, or a mixture of the silane compound (ms-1) and another silane compound, is subjected to hydrolysis and condensation to synthesize a reactive polyorganosiloxane, and then the resulting reactive polyorganosiloxane is reacted with a carboxylic acid having a monovalent organic group having 1 to 30 carbon atoms (hereinafter also referred to as a "side chain-introduced carboxylic acid"). [2s] A method of hydrolyzing and condensing a hydrolyzable silane compound (ms-2) having a monovalent organic group having 1 to 30 carbon atoms, or a mixture of the silane compound (ms-2) and another silane compound. Among these, method [1s] is preferable because it is simple and easy and can increase the introduction rate of side chains into polyorganosiloxane (PS).

[0062] Specific examples of the silane compound (ms-1) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethylmethyldimethoxysilane, 2-glycidoxyethyldimethylmethoxysilane, 2-glycidoxyethyldimethylethoxysilane, 4-glycidoxybutyltrimethoxysilane, 4-glycidoxybutylmethyldimethoxysilane, 4-glycidoxybutylmethyldiethoxysilane, 4-glycidoxybutyldimethylmethoxysilane, 4-glycidoxybutyldimethylethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 3-(3,4-epoxycyclohexyl)propyltrimethoxysilane.

[0063] The other silane compounds used in the synthesis of reactive polyorganosiloxanes are not particularly limited as long as they are hydrolyzable silane compounds. Specific examples thereof include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane; Nitrogen- and sulfur-containing alkoxysilanes, such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(3-cyclohexylamino)propyltrimethoxysilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane; Examples of the alkoxysilane include unsaturated hydrocarbon-containing alkoxysilanes such as 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and p-styryltrimethoxysilane; and trimethoxysilylpropylsuccinic anhydride.

[0064] The hydrolysis and condensation reaction of silane compounds can be carried out by reacting one or more of the above silane compounds with water, preferably in the presence of a suitable catalyst and organic solvent. The proportion of water used in the reaction is preferably 1 to 30 moles per mole of the total amount of silane compounds. Examples of catalysts include acids, alkali metal compounds, organic bases, titanium compounds, and zirconium compounds. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, and can be appropriately determined. The amount of catalyst used is preferably 0.01 to 3 moles per total amount of silane compounds. Examples of organic solvents used include hydrocarbons, ketones, esters, ethers, and alcohols. Among these, it is preferable to use a water-insoluble or slightly water-soluble organic solvent. The proportion of organic solvent used is preferably 10 to 10,000 parts by mass per 100 parts by mass of the total amount of silane compounds used in the reaction.

[0065] The hydrolysis-condensation reaction is preferably carried out by heating, for example, in an oil bath. The heating temperature is preferably 130°C or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction is complete, the organic solvent layer separated from the reaction solution is dried with a desiccant, if necessary, and the solvent is then removed to obtain the desired polyorganosiloxane. The synthesis of polyorganosiloxane is not limited to the hydrolysis-condensation reaction described above; for example, it may be carried out by reacting a hydrolyzable silane compound in the presence of oxalic acid and an alcohol.

[0066] In the method [1s], the reactive polyorganosiloxane obtained by the above reaction is then reacted with a side chain-introduced carboxylic acid. This allows the epoxy group of the reactive polyorganosiloxane to react with the carboxy group of the side chain-introduced carboxylic acid, thereby obtaining a polyorganosiloxane (PS) having a desired structure in the side chain. Specific examples of the side chain-introduced carboxylic acid include carboxylic acids having the specific and preferred examples shown as the monovalent organic group having 1 to 30 carbon atoms that the polyorganosiloxane (PS) may have in the side chain.

[0067] The content of monovalent organic groups having 1 to 30 carbon atoms in one polyorganosiloxane (PS) molecule is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, and even more preferably 15 mol% or more, relative to the silicon atoms in the polyorganosiloxane (PS). Furthermore, the content of monovalent organic groups having 1 to 30 carbon atoms in one polyorganosiloxane (PS) molecule is preferably 90 mol% or less, more preferably 80 mol% or less, relative to the silicon atoms in the polyorganosiloxane (PS). Having the content of monovalent organic groups having 1 to 30 carbon atoms in the polyorganosiloxane (PS) within the above range is advantageous in that it allows for the liquid crystal device to be driven at a sufficiently low voltage while providing a liquid crystal device with excellent liquid crystal alignment.

[0068] The reaction between the reactive polyorganosiloxane and the side chain-introduced carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. The catalyst used can be, for example, an organic base or a compound known as a so-called curing accelerator that accelerates the reaction of an epoxy compound (e.g., a tertiary organic amine, a quaternary organic amine, a quaternary ammonium salt, etc.). The amount of catalyst used is preferably 100 parts by mass or less, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the reactive polyorganosiloxane.

[0069] Examples of organic solvents used in the above reaction include hydrocarbons, ethers, esters, ketones, amides, and alcohols. The organic solvent is preferably used in a proportion such that the solids concentration (the proportion of the total mass of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by mass or more, more preferably 5 to 50% by mass. The reaction solvent may contain a small amount of water along with the organic solvent. In the above reaction, the reaction temperature is preferably 0 to 200°C, more preferably 50 to 150°C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. After completion of the reaction, it is preferable to wash the organic solvent layer separated from the reaction solution with water. After washing with water, the organic solvent layer is dried with an appropriate desiccant, if necessary, and then the solvent is removed to obtain polyorganosiloxane (PS) having the desired side chains introduced therein.

[0070] The polyorganosiloxane (PS) preferably has a solution viscosity of 1 to 500 mPa·s when made into a solution with a concentration of 10 mass %, and more preferably has a solution viscosity of 3 to 200 mPa·s.

[0071] The molecular weight of the polyorganosiloxane (PS) can be appropriately set depending on the structure of the polyorganosiloxane (PS). For example, when the polyorganosiloxane (PS) has either a cage structure or an incomplete cage structure, the weight average molecular weight (Mw) of the polyorganosiloxane (PS) is preferably 1,000 or more, more preferably 1,500 or more, and even more preferably 2,000 or more, from the viewpoint of film-forming properties. Furthermore, from the viewpoint of obtaining a liquid crystal element that achieves both high liquid crystal alignment properties and low-voltage driving, the Mw of the polyorganosiloxane (PS) is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 10,000 or less.

[0072] Furthermore, when the polyorganosiloxane (PS) has either a cage structure or an incomplete cage structure, the molecular weight distribution (Mw / Mn) of the polyorganosiloxane (PS), expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably 3.0 or less, more preferably 2.8 or less, and even more preferably 2.5 or less. In this specification, the Mw and Mn of the polyorganosiloxane are polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC).

[0073] When the polyorganosiloxane (PS) is a cyclic polysiloxane, the molecular weight of the polyorganosiloxane (PS) is preferably 300 or more, more preferably 400 or more, and even more preferably 500 or more. When the polyorganosiloxane (PS) is a cyclic polysiloxane, the molecular weight is preferably 1400 or less, and more preferably 1350 or less.

[0074] In the liquid crystal aligning agent of the present disclosure, the content of polyorganosiloxane (PS) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the solid content (components other than the solvent of the liquid crystal aligning agent) contained in the liquid crystal aligning agent. By setting the content of polyorganosiloxane (PS) within the above range, it is possible to obtain a liquid crystal element that can be driven at a low voltage to a high degree while maintaining good liquid crystal alignment.

[0075] <Other ingredients> The liquid crystal aligning agent of the present disclosure may further contain a component different from polyorganosiloxane (PS) (hereinafter also referred to as "other component"). Examples of the other component include a polymer having a main skeleton different from that of polyorganosiloxane (PS) (hereinafter also referred to as "other polymer"), a crosslinking agent, an adhesion aid, a solvent, etc.

[0076] Other polymers The main skeleton of the other polymer is not particularly limited. Examples of the other polymer include polyamic acid, polyamic acid ester, polyimide, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, and addition polymer. Examples of the addition polymer include (meth)acrylic polymer, styrene polymer, maleimide polymer, (meth)acrylic-styrene copolymer, (meth)acrylic-maleimide copolymer, (meth)acrylic-styrene-maleimide copolymer, and styrene-maleimide copolymer.

[0077] From the viewpoint of obtaining a highly reliable liquid crystal element with little afterimage while achieving low-voltage driving, the other polymer is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and addition polymer, among the above. Among these, the other polymer is particularly preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, in that it is easy to make the polyorganosiloxane (PS) unevenly distributed in the upper layer, can sufficiently enhance the effect of improving liquid crystal alignment and low-voltage driving, and can easily adjust the electrical properties.

[0078] When the liquid crystal aligning agent contains other polymers, the content of the other polymers is preferably 1 part by mass or more, more preferably 2 parts by mass or more, per 100 parts by mass of the total amount of the polyorganosiloxane (PS) and the other polymers. The content of the other polymers is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, per 100 parts by mass of the total amount of the polyorganosiloxane (PS) and the other polymers.

[0079] Crosslinking agent The liquid crystal aligning agent of the present disclosure preferably contains a crosslinking agent. By further containing a crosslinking agent, a liquid crystal device with little image retention can be obtained while achieving low-voltage operation. Examples of crosslinking agents include compounds (excluding polyorganosiloxanes (PS)) having two or more of at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a cyclic carbonate group, a hydroxy group, a protected hydroxy group, a carboxy group, a protected carboxy group, a mercapto group, a protected mercapto group, an amino group, a protected amino group, a protected isocyanate group, and a polymerizable carbon-carbon unsaturated bond group in one molecule.

[0080] From the viewpoint of obtaining a liquid crystal alignment film that exhibits good weak anchoring properties and can sufficiently suppress afterimages, the number of crosslinkable groups that the crosslinking agent has in one molecule is preferably 2 to 10, more preferably 2 to 6. The molecular weight of the crosslinking agent is preferably 100 to 1,000, more preferably 100 to 800, and even more preferably 100 to 700.

[0081] Specific examples of the crosslinking agent include compounds having an oxiranyl group or an oxetanyl group, such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, triglycidyl isocyanurate, glycerol polyglycidyl ether, pentaerythritol tetraglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, N,N',N',N'-tetraglycidyl glycoluril, 1,6-hexanediol diglycidyl ether, trimethylol Examples of such glycerols include methyl glycerol propane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, and epoxidation reaction products of 2,2'-diallylbisphenol A diallyl ether with hydrogen peroxide.

[0082] Examples of the compound having a cyclic carbonate group include compounds represented by the following formulas (d1-1) and (d1-2).

[0083] Compounds having a hydroxy group or a protected hydroxy group can preferably be compounds having a methylol group, a protected methylol group, a hydroxyalkylamide group, or a protected hydroxyalkylamide group. Specific examples of these include compounds represented by the following formulas (d2-1) to (d2-5) and (d3-1) to (d3-5).

[0084] Examples of compounds having a carboxy group or a protected carboxy group include maleic acid, itaconic acid, trimellitic acid, tetracarboxylic acid, cis-1,2,3,4-tetrahydrophthalic acid, ethylene glycol bistrimate, propylene glycol bistrimate, 4,4'-oxydiphthalic acid, and protected forms thereof.

[0085] Examples of compounds having a mercapto group or a protected mercapto group include 1,2-ethanedithiol, 1,3-propanedithiol, 1,3,4-thiadiazole-2,5-dithiol, 1,10-decanedithiol, pentaerythritol tetrakis(3-mercaptobutyrate), and 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione.

[0086] Examples of compounds having an amino group or a protected amino group include compounds represented by the following formulae (d4-1) to (d4-5).

[0087] Examples of compounds having a protected isocyanate group include compounds in which the isocyanate group in tolylene diisocyanate, xylylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, or diphenylmethane diisocyanate is protected with 3,6-dimethylpyrazole, methyl ethyl ketoxime, diethyl malonate, or ε-caprolactam, and compounds represented by the following formula (d5-1).

[0088] Examples of compounds having a polymerizable carbon-carbon unsaturated bond group include compounds having a (meth)acryloyl group, a maleimide group, an alkenyl group, a vinylphenyl group, a vinyl ether group, or a 3-methylenetetrahydrofuran-2(3H)-one-5-yl group. Specific examples of these include ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and compounds represented by the following formulas (d6-1) to (d6-7).

[0089] [ka] [ka] (In formula (d2-4), Ac is an acetyl group.) [ka] [ka] [ka] [ka]

[0090] Among the above crosslinking agents, compounds having two or more crosslinkable groups in one molecule, each of which is at least one type selected from the group consisting of an oxiranyl group, an oxetanyl group, a cyclic carbonate group, a hydroxyalkylamide group, a protected hydroxyalkylamide group, an amino group, a protected amino group, and a protected isocyanate group, are preferred, and compounds having two or more crosslinkable groups in one molecule, each of which is at least one type selected from the group consisting of an oxiranyl group, an oxetanyl group, a cyclic carbonate group, a hydroxyalkylamide group, and a protected hydroxyalkylamide group, are more preferred, in terms of being able to achieve low-voltage driving while maintaining good liquid crystal alignment properties and obtain liquid crystal elements with sufficiently reduced afterimages.

[0091] As the crosslinking agent, a compound having no aromatic ring (hereinafter also referred to as "aliphatic crosslinking agent") can be preferably used, since it can provide a liquid crystal element having excellent liquid crystal alignment properties while sufficiently achieving low-voltage driving of the liquid crystal element. The aliphatic crosslinking agent may be a compound having a chain structure or may have a cyclic structure. Specific examples of the aliphatic crosslinking agent include the compounds exemplified above that have no aromatic ring.

[0092] The content of the crosslinking agent is preferably 0.5 parts by mass or more relative to 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent (i.e., the total amount of polymer (P) and other polymers) from the viewpoint of obtaining a liquid crystal alignment film that exhibits weak anchoring properties while improving the mechanical properties and adhesion of the liquid crystal alignment film, and from the viewpoint of obtaining a liquid crystal device with sufficiently reduced afterimages. The content of the crosslinking agent is more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the total amount of polymer components. Furthermore, from the viewpoint of obtaining a liquid crystal device that exhibits good liquid crystal alignment properties, the content of the crosslinking agent is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the total amount of polymer components.

[0093] Adhesion aid The adhesion aid is a component that improves the adhesion between a liquid crystal alignment film formed using a liquid crystal aligning agent and a substrate or a sealing material. A functional silane coupling agent having a reactive functional group can be preferably used as the adhesion aid. Examples of the reactive functional group possessed by the functional silane coupling agent include a carboxy group, a (meth)acryloyl group, an oxiranyl group, an oxetanyl group, a vinyl group, and an isocyanate group.

[0094] Specific examples of functional coupling agents include trimethoxysilylbenzoic acid, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane.

[0095] When the liquid crystal aligning agent of the present disclosure contains an adhesion aid, the content of the adhesion aid is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0096] ·solvent The liquid crystal aligning agent of the present disclosure is prepared as a liquid composition obtained by dispersing or dissolving polyorganosiloxane (PS) and other components used as needed, preferably in a suitable solvent.

[0097] The solvent is preferably an organic solvent, specific examples of which include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, lactams such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and γ-butyrolactam, ureas such as 1,2-dimethyl-2-imidazolidinone and 1,3-dimethyl-2-imidazolidinone, lactones such as γ-butyrolactone, carbonates such as ethylene carbonate and propylene carbonate, etc. (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether (butyl cellosolve), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether; Alkyl lactate esters such as methyl lactate, ethyl lactate, and butyl lactate; alkyl alcohols which may have a straight-chain, branched, or cyclic structure such as methanol, ethanol, propanol, butanol, isopropanol, isobutanol, t-butanol, octanol, 2-ethylhexanol, and cyclohexanol; alkoxy alcohols such as 3-methoxy-1-butanol; keto alcohols such as diacetone alcohol; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. (Poly)alkylene glycol monoalkyl ether acetates such as acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, etc.; ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran, etc.; ketones such as methyl ethyl ketone, diisobutyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, etc.; diacetates such as propylene glycol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanediol diacetate; alkoxycarboxylic acid esters such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, and 3-methyl-3-methoxybutylpropionate; other esters such as ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl formate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutanoate; aromatic hydrocarbons such as toluene and xylene; and phenols such as phenol and methylphenol.

[0098] In addition to the above, other components contained in the liquid crystal aligning agent of the present disclosure include, for example, surfactants, antioxidants, metal chelate compounds, curing accelerators, fillers, dispersants, photosensitizers, etc. The blending ratio of other components can be appropriately selected depending on each compound within a range that does not impair the effects of the present disclosure.

[0099] The solid content concentration of the liquid crystal aligning agent of the present disclosure (the proportion of the total mass of the components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected taking into consideration viscosity, volatility, etc. The solid content concentration of the liquid crystal aligning agent of the present disclosure is preferably in the range of 1 to 10 mass %. When the solid content concentration is 1 mass % or more, a sufficient thickness of the coating film can be ensured, and a liquid crystal alignment film exhibiting better liquid crystal alignment properties can be obtained. Furthermore, when the solid content concentration is 10 mass % or less, a coating film with an appropriate thickness can be obtained, and a liquid crystal alignment film exhibiting good liquid crystal alignment properties can be easily obtained. Furthermore, the viscosity of the liquid crystal aligning agent becomes appropriate, and good coatability can be ensured.

[0100] <Weak anchoring liquid crystal alignment film and its manufacturing method> The liquid crystal alignment film of the present disclosure is a weak anchoring liquid crystal alignment film manufactured using the liquid crystal aligning agent prepared as described above. The method for producing a weak anchoring liquid crystal alignment film using the liquid crystal aligning agent of the present disclosure is not particularly limited, and can be performed by the same method as when producing a liquid crystal alignment film using a conventionally known liquid crystal aligning agent. In terms of easy film formation, a method of forming the film by applying the liquid crystal aligning agent of the present disclosure onto a substrate and preferably heating the coated surface is preferred.

[0101] The substrate on which the weak anchoring liquid crystal alignment film is formed is not particularly limited. Examples of the substrate include transparent substrates made of glass such as float glass and soda glass, and plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin).

[0102] The method for applying the liquid crystal aligning agent to the substrate is not particularly limited. The liquid crystal aligning agent can be applied by, for example, a spin coating method, a printing method (for example, an offset printing method, a flexographic printing method, etc.), an inkjet method, a slit coating method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, etc.

[0103] After the liquid crystal alignment agent is applied, preheating (pre-baking) is preferably carried out to prevent dripping of the liquid crystal alignment agent. The pre-baking temperature is preferably 30 to 200°C, and the pre-baking time is preferably 0.25 to 10 minutes. Thereafter, a baking (post-baking) step is carried out to further remove the solvent. The baking temperature (post-baking temperature) is preferably 80 to 280°C, more preferably 80 to 250°C. The post-baking time is preferably 5 to 200 minutes. The thickness of the formed film is preferably 0.001 to 2.5 μm. By the above-mentioned procedure, a weak anchoring liquid crystal alignment film can be easily produced. Note that the coating film after post-baking may be subjected to an alignment treatment (for example, a rubbing alignment treatment or a photo-alignment treatment) as needed to obtain a weak anchoring liquid crystal alignment film.

[0104] <Liquid crystal element manufacturing method> The liquid crystal element of the present disclosure can be manufactured, for example, by a method including the following steps A and B. The order of steps A and B is not particularly limited, and step A may be performed after step B, or step B may be performed after step A. Furthermore, steps A and B may be performed simultaneously. Step A: A step of forming a weak anchoring liquid crystal alignment film on one of the pair of substrates using a liquid crystal alignment agent for forming a weak anchoring film. Step B: A step of forming a strong anchoring liquid crystal alignment film on the other substrate of the pair of substrates (i.e., the substrate on which the weak anchoring liquid crystal alignment film is not formed).

[0105] Step A is preferably performed by Step 1 described below, and Step B is preferably performed by Steps 1 and 2 described below. Furthermore, a liquid crystal element can be obtained by constructing a liquid crystal cell in Step 3 using the substrate on which the liquid crystal alignment film obtained in Steps A and B is formed. Note that in Step 1, the substrate used varies depending on the desired operation mode. Steps 2 and 3 are common to all operation modes.

[0106] <Step 1: Formation of coating film> In step 1, a liquid crystal aligning agent is applied to the surface of each substrate, and the applied surface is preferably heated to form a coating film on the substrate. As the liquid crystal aligning agent for forming a strong anchoring liquid crystal alignment film, a conventionally known liquid crystal aligning agent can be appropriately used.

[0107] When manufacturing an IPS or FFS liquid crystal device, for example, a pair of substrates is used: an electrode substrate with comb-shaped patterned electrodes and a counter substrate without electrodes. Examples of the electrodes include a transparent conductive film. Examples of the transparent conductive film include a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO2) and an ITO film made of indium oxide-tin oxide (In2O3-SnO2). Examples of the liquid crystal alignment film formed on the electrode substrate and the counter substrate include a first embodiment in which a strong anchoring liquid crystal alignment film is formed on the electrode substrate and a weak anchoring liquid crystal alignment film is formed on the counter substrate; and a second embodiment in which a weak anchoring liquid crystal alignment film is formed on the electrode substrate and a strong anchoring liquid crystal alignment film is formed on the counter substrate. Of these, the first embodiment is preferred from the viewpoint of low-voltage operation of the liquid crystal device.

[0108] <Step 2: Alignment Treatment> When manufacturing an IPS or FFS liquid crystal device, it is preferable to subject the coating film formed on the substrate in step 1 to a treatment (alignment treatment) to impart liquid crystal alignment ability. Preferred alignment treatments include rubbing the surface of the coating film formed on the substrate with cotton, nylon, or the like, or photoalignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. Furthermore, from the perspective of obtaining a liquid crystal device exhibiting good liquid crystal alignment properties, it is preferable to apply a liquid crystal alignment agent for forming a strong anchoring liquid crystal alignment film to one of the electrode substrate and the counter substrate, and then perform alignment treatment only on the coating film thus formed. The liquid crystal alignment agent used to form the strong anchoring liquid crystal alignment film preferably contains a crosslinking agent, as this can improve mechanical strength and seal adhesion.

[0109] Furthermore, according to the weak anchoring liquid crystal alignment film formed by the liquid crystal aligning agent of the present disclosure, a liquid crystal element exhibiting good liquid crystal alignment properties can be obtained without performing alignment treatments such as rubbing alignment treatment or photo-alignment treatment on the coating film for obtaining the weak anchoring liquid crystal alignment film. Utilizing these properties, the weak anchoring liquid crystal alignment film formed by the liquid crystal aligning agent of the present disclosure may be disposed as a protective film provided on a color filter in a liquid crystal element, so that the weak anchoring liquid crystal alignment film has the function of a protective film (specifically, planarization and protection from impurities, humidity, etc.).

[0110] <Step 3: Construction of liquid crystal cell> Next, a liquid crystal cell is produced using two substrates arranged opposite each other, one with a strong anchoring liquid crystal alignment film and the other with a weak anchoring liquid crystal alignment film, with a liquid crystal layer disposed between them. Examples of methods for producing a liquid crystal cell include: arranging two substrates opposite each other with a gap between them so that the liquid crystal alignment films face each other; bonding the peripheries of the two substrates together with a sealant; injecting liquid crystal into the cell gap surrounded by the substrate surfaces and the sealant; and sealing the injection hole; or an ODF method. Examples of sealants that can be used include epoxy resins containing a curing agent and aluminum oxide spheres as spacers. Examples of liquid crystals that constitute the liquid crystal layer include nematic liquid crystals and smectic liquid crystals, with nematic liquid crystals being preferred.

[0111] When manufacturing a liquid crystal display element, a polarizing plate is subsequently attached to the outer surface of the liquid crystal cell. Examples of polarizing plates include a polarizing film called an "H film" made by stretching and aligning polyvinyl alcohol and absorbing iodine, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

[0112] The liquid crystal element of the present disclosure can be effectively applied to various applications, specifically, for example, various display devices such as watches, portable game machines, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, head-mounted displays, and smart glasses, as well as light control devices and retardation films.

[0113] According to the present disclosure described above in detail, the following aspects are provided. [Aspect 1] A pair of substrates consisting of a first substrate and a second substrate, a liquid crystal layer containing liquid crystal molecules, A liquid crystal element comprising: a weak anchoring liquid crystal alignment film formed on one of the first substrate and the second substrate; and a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film formed on the other substrate; and the weak anchoring liquid crystal alignment film is formed from a liquid crystal alignment agent containing polyorganosiloxane. [Aspect 2] The liquid crystal element according to [Aspect 1], wherein the slow axes of the liquid crystal molecules are aligned substantially parallel to the substrate surfaces when the liquid crystal element is not driven. [Aspect 3] The liquid crystal device according to [Aspect 1] or [Aspect 2], wherein the strong anchoring liquid crystal alignment film is a rubbed alignment film or a photo-alignment film. [Embodiment 4] The liquid crystal device according to any one of [Embodiment 1] to [Embodiment 3], wherein the polyorganosiloxane has at least one of a cage structure, an incomplete cage structure, and a cyclic structure. [Aspect 5] The liquid crystal device according to any one of [Aspect 1] to [Aspect 4], wherein the polyorganosiloxane does not have a photoalignable group. [Embodiment 6] The liquid crystal device according to any one of [Embodiment 1] to [Embodiment 5], wherein the polyorganosiloxane contains a structural unit represented by the above formula (S-1). [Aspect 7] The liquid crystal device according to any one of [Aspect 1] to [Aspect 5], wherein the polyorganosiloxane is a cyclic polysiloxane having a molecular weight of 1,500 or less. [Embodiment 8] The liquid crystal device according to any one of [Embodiment 1] to [Embodiment 7], wherein the polyorganosiloxane does not have a benzene ring. [Aspect 9] A liquid crystal element according to any one of [Aspect 1] to [Aspect 8], wherein the polyorganosiloxane does not have a partial structure in which two or more cyclohexane rings are bonded by a single bond, -COO-, or -NR- (wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). [Aspect 10] The liquid crystal device according to any one of [Aspect 1] to [Aspect 9], wherein the liquid crystal aligning agent further contains a polymer having a main skeleton different from that of the polyorganosiloxane. [Embodiment 11] The liquid crystal device according to any one of [Embodiment 1] to [Embodiment 10], wherein the weak anchoring liquid crystal alignment film is a film that has not been subjected to an alignment treatment. [Embodiment 12] A liquid crystal aligning agent for forming a weak anchoring film, which is used to form a weak anchoring liquid crystal alignment film, and contains polyorganosiloxane. [Aspect 13] The liquid crystal aligning agent for forming a weak anchoring film according to [Aspect 11], wherein the polyorganosiloxane has at least one of a cage structure, an incomplete cage structure, and a cyclic structure. [Aspect 14] The liquid crystal aligning agent for forming a weak anchoring film according to [Aspect 12] or [Aspect 13], wherein the polyorganosiloxane does not have a photoalignable group. [Embodiment 15] The liquid crystal aligning agent for forming a weak anchoring film according to any one of [Embodiment 12] to [Embodiment 14], wherein the polyorganosiloxane contains a structural unit represented by the above formula (S-1). [Embodiment 16] The polyorganosiloxane is a polymer having a structural unit represented by the above formula (S-2), an alkyl group having 1 to 30 carbon atoms, "*-R 2 -(OR 3 ) r -OR 4 and a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring. [Aspect 17] The liquid crystal aligning agent for forming a weak anchoring film according to any one of [Aspect 12] to [Aspect 14], wherein the polyorganosiloxane is a cyclic polysiloxane having a molecular weight of 1,500 or less. [Embodiment 18] The liquid crystal aligning agent for forming a weak anchoring film according to any one of [Embodiment 12] to [Embodiment 17], wherein the polyorganosiloxane does not have a benzene ring. [Aspect 19] A liquid crystal aligning agent for forming a weak anchoring film according to any one of [Aspect 12] to [Aspect 18], wherein the polyorganosiloxane does not have a partial structure in which two or more cyclohexane rings are bonded by a single bond, -COO-, or -NR- (wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). [Embodiment 20] The liquid crystal aligning agent for forming a weak anchoring film according to any one of [Embodiment 12] to [Embodiment 19], further comprising a crosslinking agent. [Aspect 21] The liquid crystal aligning agent for forming a weak anchoring film according to [Aspect 20], wherein the crosslinking agent does not have an aromatic ring. [Aspect 22] The liquid crystal aligning agent for forming a weak anchoring film according to [Aspect 20] or [Aspect 21], wherein the crosslinking agent has two or more of at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a cyclic carbonate group, a hydroxy group, a protected hydroxy group, a carboxy group, a protected carboxy group, a mercapto group, a protected mercapto group, an amino group, a protected amino group, a protected isocyanate group, and a polymerizable carbon-carbon unsaturated bond group in one molecule. [Embodiment 23] The liquid crystal aligning agent for forming a weak anchoring film according to any one of [Embodiment 12] to [Embodiment 22], further comprising a polymer having a main skeleton different from that of the polyorganosiloxane. [Embodiment 24] A method for manufacturing a liquid crystal element, comprising the steps of: forming a weak anchoring liquid crystal alignment film on one of a pair of substrates using a liquid crystal alignment agent for forming a weak anchoring film described in any one of [Embodiment 12] to [Embodiment 23]; and forming a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film on the other substrate. [Aspect 25] The method for producing a liquid crystal device according to [Aspect 24], wherein the strong anchoring liquid crystal alignment film is a rubbed alignment film or a photo-alignment film. [Example]

[0114] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0115] In the following examples, the imidization rate of polyimide and the molecular weight (Mw, Mn) of the polymer (polyorganosiloxane) were measured by the following methods. <Imidization rate of polyimide> The polyimide solution was poured into pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature. After that, it was dissolved in deuterated dimethyl sulfoxide and measured at room temperature using tetramethylsilane as a standard substance. 1 H-NMR measurement was carried out. 1 The imidization rate [%] was calculated from the H-NMR spectrum using the following formula (1). Imidization rate [%] = (1-(β 1 / (β 2 ×α)))×100 …(1) (In formula (1), β 1 is the peak area due to the proton of the NH group that appears at a chemical shift of around 10 ppm, and β 2 is the peak area due to other protons, and α is the ratio of the number of other protons to one proton of the NH group in the polymer precursor (polyamic acid). <Molecular weight (Mw, Mn) of polymer (polyorganosiloxane)> The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) under the following conditions. Equipment: Showa Denko "GPC-101" GPC column: Shimadzu GLC's "GPC-KF-801", "GPC-KF-802", "GPC-KF-803" and "GPC-KF-804" Mobile phase: tetrahydrofuran (THF) Column temperature: 40℃ Flow rate: 1.0mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Detector: differential refractometer Standard material: monodisperse polystyrene

[0116] The abbreviations of the compounds used in the following examples are shown below. For convenience, hereinafter, "a compound represented by formula (X)" may be simply referred to as "compound (X)." In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified.

[0117] (Siloxane Monomer) S-1 to S-4 [ka]

[0118] (Cyclic polysiloxane) CS-1, CS-2 [ka]

[0119] (Reactive Compounds (Carboxylic Acids)) C-1 to C-12 [ka]

[0120] (Tetracarboxylic dianhydrides) TA-1 to TA-7 [ka]

[0121] (Diamine) DA-1 to DA-21 [ka] [ka]

[0122] (Additives) AD-1 to AD-8 [ka] [ka]

[0123] <Polymer synthesis> 1. Synthesis of polyorganosiloxanes (polymers (PS-1) to (PS-18), (PCS-1) to (PCS-3)) [Synthesis Example 1-1] A 1000 mL three-neck flask was charged with 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (compound (S-1)) as a siloxane monomer, 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine, and mixed at room temperature. Next, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the mixture was stirred under reflux while reacting at 80°C for 6 hours. After the reaction was completed, the organic layer was removed and washed with a 0.2% by weight aqueous solution of ammonium nitrate until the water became neutral. The solvent and water were then distilled off under reduced pressure. An appropriate amount of methyl isobutyl ketone was added to obtain a 50% by weight solution of polymer (ESSQ-1), a polyorganosiloxane having epoxy groups. In a 500 mL three-neck flask, 15 mol% of compound (C-1) relative to the amount of epoxy groups in the polymer (ESSQ-1), 1.00 g of tetrabutylammonium bromide, 20.0 g of a solution containing the polymer (ESSQ-1), and 290.0 g of methyl isobutyl ketone were added and stirred at 90 ° C for 18 hours. After cooling to room temperature, the separation and washing operation with distilled water was repeated 10 times. The organic layer was then recovered, concentrated using a rotary evaporator, and diluted with NMP twice. The solids concentration was then adjusted to 10% by mass using NMP to obtain an NMP solution of polyorganosiloxane (referred to as polymer (PS-1)). 1 H-NMR measurement, 29 The structure of the polymer (PS-1) was confirmed by Si-NMR measurement, gel permeation chromatography (GPC), and quadrupole time-of-flight mass spectrometry (QTOF-MS), and it was confirmed to be a polyorganosiloxane mainly composed of a cage structure that was a mixture of a cage structure and an incomplete cage structure. The weight-average molecular weight of the polymer (PS-1) was 2,100.

[0124] [Synthesis Examples 1-2 to 1-18] The same procedure as in Synthesis Example 1-1 was carried out except that the types and amounts of siloxane monomers and carboxylic acids were changed as shown in Table 1, to obtain polyorganosiloxanes (referred to as polymers (PS-2) to (PS-18)). 1 H-NMR measurement,29 The structures were confirmed by Si-NMR measurement, GPC, and QTOF-MS, and all polymers were confirmed to be polyorganosiloxanes mainly composed of a cage structure that was a mixture of a cage structure and an incomplete cage structure. The weight-average molecular weights of each polymer are shown in Table 1.

[0125] [Table 1]

[0126] [Synthesis Example 1-19] A 500 mL three-neck flask was charged with 40.0 g of cyclic polysiloxane (CS-1), 25 mol% of compound (C-1) relative to the amount of epoxy groups in the cyclic polysiloxane (CS-1), 4.00 g of tetrabutylammonium bromide, and 290.0 g of propylene glycol methyl ether acetate, and the mixture was stirred at 100 °C for 8 hours. After cooling to room temperature, the mixture was subjected to 10 cycles of separation and washing with distilled water. The organic layer was then recovered, concentrated twice using a rotary evaporator, and diluted with NMP. The solids concentration was then adjusted to 10% by mass using NMP, yielding an NMP solution of polyorganosiloxane (referred to as polymer (PCS-1)). The weight-average molecular weight of polymer (PCS-1) was 900.

[0127] [Synthesis Examples 1-20 and 1-21] Polyorganosiloxanes (referred to as polymers (PCS-2) and (PCS-3)) were obtained in the same manner as in Synthesis Example 1-19, except that the types and amounts of cyclic polysiloxane and carboxylic acid were changed as shown in Table 2. The weight-average molecular weights of the respective polymers are shown in Table 2.

[0128] [Table 2]

[0129] 2. Synthesis of polyamic acid [Synthesis Example 2-1] 100 parts by mole of compound (TA-1) as a tetracarboxylic dianhydride and 100 parts by mole of compound (DA-1) as a diamine compound were dissolved in N-methyl-2-pyrrolidone (NMP), and the mixture was allowed to react at 60°C for 6 hours to obtain a solution containing 20% ​​by mass of polyamic acid (referred to as polymer (PI-1)).

[0130] [Synthesis Examples 2-2 to 2-9, 2-11 to 2-15] Polyamic acids (polymers (PI-2) to (PI-9), (PI-11) to (PI-15)) were obtained by the same procedure as in Synthesis Example 2-1, except that the types and amounts of the tetracarboxylic dianhydrides and diamine compounds used were changed as shown in Table 3. In Table 3, the values ​​for the tetracarboxylic dianhydrides (acid dianhydrides 1 and 2) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of tetracarboxylic dianhydrides used in the synthesis of the polymer. The values ​​for the diamine compounds (diamines 1 to 4) represent the ratio (molar ratio) of each compound to 100 parts by mole of the total amount of diamine compounds used in the synthesis of the polymer.

[0131] 3. Polyimide Synthesis [Synthesis Example 2-10] 100 moles of compound (TA-4) as a tetracarboxylic dianhydride, and 30 moles of compound (DA-5), 40 moles of compound (DA-8), and 30 moles of compound (DA-9) as diamine compounds were dissolved in NMP and reacted at 60°C for 6 hours to obtain a solution containing 20% ​​by weight of polyamic acid. Next, NMP was added to the resulting polyamic acid solution to obtain a solution with a polyamic acid concentration of 10% by weight, and pyridine and acetic anhydride were added, followed by a dehydration ring-closing reaction at 80°C for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with fresh NMP to obtain a solution containing 15% by weight of polyimide with an imidization rate of approximately 60% (referred to as polymer (PI-10)).

[0132] [Table 3]

[0133] <Preparation of Liquid Crystal Alignment Agent> (1) Preparation of liquid crystal alignment agent for forming weak anchoring film [Preparation Example 1] A solution containing 50 parts by weight of the polymer (PS-1) obtained in Synthesis Example 1-1 and a solution containing 50 parts by weight of the polymer (PI-1) obtained in Synthesis Example 2-1 were mixed, and 5 parts by weight of compound (AD-8) was added to this mixture, and the mixture was diluted with N-methyl-2-pyrrolidone (NMP), gamma butyrolactone (GBL), butyl cellosolve (BC), diacetone alcohol (DAA), and diethylene glycol diethyl ether (DEDG) to obtain a solution with a solvent composition of NMP:GBL:BC:DAA:DEDG = 30:30:15:15:10 (mass ratio) and a solids concentration of 3.5% by weight. This solution was filtered through a 0.2 μm pore size filter to prepare a liquid crystal alignment agent (AL-1) for forming a weak anchoring film.

[0134] [Preparation Examples 2-21, 28-30] Liquid crystal alignment agents for forming weak anchoring films (AL-2) to (AL-21), (AL-28) to (AL-30) were prepared in the same manner as in Preparation Example 1, except that the types and amounts of polymers and additives were changed as shown in Table 4.

[0135] (2) Preparation of liquid crystal alignment agent for forming strong anchoring film [Preparation Examples 22-27] Liquid crystal aligning agents (AL-22) to (AL-27) for forming strong anchoring films were prepared in the same manner as in Preparation Example 1, except that the types and amounts of polymers and additives were changed as shown in Table 4.

[0136] [Table 4]

[0137] <Production and evaluation of liquid crystal elements (FFS type liquid crystal display elements)> An FFS-mode liquid crystal cell was fabricated and its various characteristics were evaluated. First, a substrate (electrode substrate) with an electrode pair consisting of a bottom electrode without a pattern, an insulating layer made of silicon nitride film, and a top electrode patterned in a comb-like shape, formed in this order on one side of a glass substrate, and an opposing glass substrate (opposite substrate) with no electrode formed thereon were prepared. A schematic plan view of the top electrode used is shown in Figure 2. Note that Figure 2(a) is a top view of the top electrode, and Figure 2(b) is an enlarged view of the area C1 enclosed by the dashed line in Figure 2(a). In this example, the line width d1 of the electrode was 4 μm, and the distance d2 between the electrodes was 6 μm. Four systems of drive electrodes, electrode A, electrode B, electrode C, and electrode D, were used as the top electrodes (Figure 3). Note that the bottom electrode acts as a common electrode that acts on all four systems of drive electrodes, and each of the areas of the four systems of drive electrodes becomes a pixel area.

[0138] [Example 1: Rubbed Alignment FFS-Type Liquid Crystal Display Element] 1. Liquid crystal display element manufacturing (1) Formation of weakly anchoring liquid crystal alignment film A liquid crystal alignment agent (AL-1) for forming a weak anchoring film was applied to one of the opposing substrates using a spin coater, heated on a hot plate at 80°C for 1 minute, and then heated in an oven at 230°C with the interior replaced with nitrogen for 30 minutes to form a weak anchoring liquid crystal alignment film with an average thickness of 100 nm.

[0139] (2) Formation of strong anchoring liquid crystal alignment film by rubbing alignment method A liquid crystal alignment agent (AL-26) for forming a strong anchoring film was applied to the electrode surface of the electrode substrate using a spin coater. The substrate was then heated on a hot plate at 80°C for 1 minute, followed by heating in a nitrogen-purged oven at 230°C for 30 minutes to form a coating with an average thickness of 100 nm. The coating surface was then rubbed twice using a rubbing machine equipped with a roll wrapped in rayon cloth at a roll rotation speed of 1,000 rpm, a stage movement speed of 30 mm / s, and a pile depth of 0.3 mm. The rubbing direction was set perpendicular to the direction of the double-headed arrow in Figure 2(b). The rubbed coating was then ultrasonically cleaned in ultrapure water for 1 minute and then dried in an oven at 100°C for 10 minutes to form a strong anchoring liquid crystal alignment film.

[0140] (3) Fabrication of rubbed alignment FFS type liquid crystal cell An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was dispensed onto the outer periphery of the surface bearing the liquid crystal alignment film of one of the substrates prepared in steps (1) and (2), leaving a liquid crystal injection port. The surfaces bearing the liquid crystal alignment films of the pair of substrates were then pressed together, facing each other, and the adhesive was thermally cured at 150°C for 1 hour. Next, a positive liquid crystal (MLC-7028-100, manufactured by Merck) was filled into the gap between the substrates through the liquid crystal injection port, and the liquid crystal injection port was then sealed with an epoxy adhesive. To eliminate flow alignment during liquid crystal injection, the substrates were heated to 120°C and then slowly cooled to room temperature.

[0141] 2. Evaluation (1) Evaluation of liquid crystal alignment The FFS-type liquid crystal cells manufactured in 1.(3) above were observed under a microscope (magnification: 50x) to evaluate the presence or absence of abnormal domains based on the change in brightness when a voltage was turned on and off (applied and removed). When no abnormal domains were observed, the cell was rated as "good (○)," and when abnormal domains were observed, the cell was rated as "bad (×)." As a result, the liquid crystal alignment in this example was judged to be "good (○)."

[0142] (2) Evaluation of low-voltage driving The FFS-mode liquid crystal cell fabricated in 1.(3) above was sandwiched between two polarizing plates to minimize brightness, and the liquid crystal cell (liquid crystal display element) with the polarizing plates was placed between a backlight and a luminance meter, with the optical axis aligned. Voltages up to 10 V were then applied to the liquid crystal display element in 0.1 V increments. The VT curve was obtained by measuring the brightness versus applied voltage, and the voltage at which brightness was maximized was estimated. For evaluation, a liquid crystal display element was prepared as a reference cell, with a liquid crystal alignment film formed on the opposing substrate by the rubbing alignment method using the same liquid crystal alignment agent (AL-26) for forming a strong anchoring film as the electrode substrate. The maximum brightness voltage of the liquid crystal display element fabricated in each example was evaluated based on the degree to which the voltage was reduced relative to the maximum brightness voltage of the reference cell. A liquid crystal display element whose maximum brightness voltage was reduced by 0.8 V or more compared to the maximum brightness voltage of the reference cell was rated as "good (○)", a liquid crystal display element whose maximum brightness voltage was reduced by 0.4 V or more but less than 0.8 V compared to the maximum brightness voltage of the reference cell was rated as "passable (△)", and a liquid crystal display element whose maximum brightness voltage was reduced by less than 0.4 V compared to the maximum brightness voltage of the reference cell was rated as "poor (×)". As a result, this example was rated as "passable (△)".

[0143] (3) Evaluation of AC image retention characteristics The FFS-type liquid crystal cell manufactured in 1.(3) above was measured for the change in liquid crystal azimuth angle before and after driving for two days by applying an AC voltage that resulted in maximum brightness using a birefringence meter (AXOSTEP high-precision Mueller matrix imaging polarimeter, manufactured by AXOMETRICS). The evaluation was based on the following criteria: a change in liquid crystal azimuth angle of less than 0.5 degrees was rated "good (○)", a change of 0.5 degrees to less than 1 degree was rated "fair (△)", and a change of 1 degree or more was rated "poor (×)". The smaller the change in liquid crystal azimuth angle, the less likely AC afterimages are to occur even when the liquid crystal display element is driven for a long period of time, and the better the liquid crystal alignment. As a result, this example was rated "fair (△)".

[0144] (4) Evaluation of sealant adhesion A weakly anchoring liquid crystal alignment agent (AL-1) and a strongly anchoring liquid crystal alignment agent (AL-26) were each applied to glass substrates using a spin coater, heated on a hot plate at 80°C for 1 minute, and then heated in a nitrogen-purged oven at 230°C for 30 minutes to produce two glass substrates with coatings of an average thickness of 100 nm. Next, an ODF sealant (Sekisui Chemical Co., Ltd., S-WB42) was applied to the center of the coated surface of one glass substrate, and the other glass substrate was bonded so that the coating and ODF sealant were in contact. The amount of ODF sealant applied was set so that the diameter of the ODF sealant after the substrates were bonded was 3 mm. A metal halide lamp was then used to apply 30,000 J / m 2 After irradiating the cells with light (equivalent to 365 nm), they were heated in an oven at 120°C for 1 hour to obtain evaluation cells. Then, the evaluation cells were pressed using a small tabletop tester (model number: EZ-LX) manufactured by Shimadzu Corporation, and the pressure (N) at which the membrane peeled off (mainly due to interface failure between the ODF sealant and the membrane or cohesive failure within the ODF sealant) was measured. The pressure (N) at the time of peeling was calculated based on the area (mm ) of the ODF sealant. 2 ) to determine the adhesion (N / mm 2 ) was calculated. The evaluation was based on a pressure measurement of 1.5N / mm 2 If it was above 1.0N / mm, it was considered "Good (○)" 2 More than 1.5N / mm 2 If it is less than 1.0N / mm, it is "Fair (△)". 2 If the value was less than 100%, it was rated as "poor (×)". As a result, this example was rated as "good (◯)".

[0145] (5) Evaluation of liquid crystal response speed The liquid crystal cell prepared in 1.(3) above was sandwiched between two polarizing plates arranged in a crossed Nicol configuration and then connected to a function generator. The liquid crystal cell connected to the function generator was placed on a backlight. First, the luminance of light transmitted through the liquid crystal cell without applying voltage was measured using a photomultimeter. This value was designated as 0% relative transmittance. Next, a square wave with a positive / negative amplitude corresponding to the maximum luminance voltage obtained in 2.(2) Low-Voltage Driving Evaluation was applied between the electrodes of the liquid crystal cell using the function generator for 1 second. The transmittance was measured in the same manner as above, and this value was designated as 100% relative transmittance. Furthermore, a square wave with a positive / negative amplitude corresponding to the maximum luminance voltage obtained in 2.(2) Low-Voltage Driving Evaluation was applied to each liquid crystal cell using the function generator. The time required for the relative transmittance to change from 10% to 90% was measured, and this time was defined as the response speed of the liquid crystal in the ON state (when voltage is applied). In addition, when the application of the square wave was stopped and switched to a 0V state, the time until the relative transmittance changed from 90% to 10% was measured, and this time was defined as the response speed in the OFF state (when the voltage application was removed). For the response speed in the ON state and the response speed in the OFF state, a response speed of less than 50 ms was rated as "good (○)", a response speed of 50 ms or more but less than 70 ms was rated as "passable (△)", and a response speed of 70 ms or more was rated as "poor (×)". As a result, in this example, the response speed in the ON state and the response speed in the OFF state were both rated as "good (○)".

[0146] [Examples 2 to 18, 32] Rubbed alignment FFS-type liquid crystal display elements were manufactured in the same manner as in Example 1, except that the types of liquid crystal alignment agents used (alignment agent for forming a weak anchoring film and liquid crystal alignment agent for forming a strong anchoring film) were changed as shown in Table 5, and various evaluations were performed. The evaluation results are shown in Table 5.

[0147] [Comparative Example 1] FFS-type liquid crystal display elements were manufactured and evaluated in the same manner as in Example 1, except that the type of liquid crystal alignment agent used was changed as shown in Table 5 and the coating film formed on the opposing substrate was also subjected to rubbing treatment. When the pair of substrates were stacked, the rubbing directions of the respective substrates were set to be antiparallel. The evaluation results are shown in Table 5.

[0148] Comparative Example 2 FFS-type liquid crystal display elements were produced and evaluated in the same manner as in Example 1, except that the type of liquid crystal alignment agent used was changed as shown in Table 5. Note that the coating film formed on the opposing substrate was not subjected to a rubbing treatment, as in Example 1. The evaluation results are shown in Table 5.

[0149] [Example 19: Photo-aligned FFS-type liquid crystal display element] 1. Liquid crystal display element manufacturing (1) Formation of weakly anchoring liquid crystal alignment film A liquid crystal alignment agent (AL-1) for forming a weak anchoring film was applied to one side of the opposing substrate using a spin coater, heated on a hot plate at 80°C for 1 minute, and then heated in an oven at 230°C with the interior replaced with nitrogen for 30 minutes to form a weak anchoring liquid crystal alignment film with an average thickness of 100 nm.

[0150] (2) Formation of strong anchoring liquid crystal alignment film by photoalignment method A liquid crystal alignment agent (AL-22) for forming a strong anchoring film was applied to the electrode-forming surface of the electrode substrate using a spin coater. It was then heated on a hot plate at 80°C for 1 minute, and then heated in a nitrogen-purged oven at 230°C for 30 minutes to form a coating film with an average thickness of 100 nm. A Hg-Xe lamp was used to irradiate the surface of this coating film with 200 mJ / cm of linearly polarized ultraviolet light containing a 254 nm emission line. 2The photo-alignment treatment was performed by irradiating the polarized UV light from the normal direction of the substrate. The direction of the polarization plane was set so that the direction of the line segment projected onto the substrate was parallel to the direction of the double-headed arrow in Figure 2(b). The photo-alignment-treated coating film was then heat-treated in a nitrogen-purged oven at 230°C for 30 minutes to form a strong anchoring liquid crystal alignment film.

[0151] (3) Fabrication of photo-aligned FFS-type liquid crystal cells An FFS-mode liquid crystal display element was produced in the same manner as in Example 1 using the pair of substrates prepared in (1) and (2) above.

[0152] 2. Evaluation Except for using the photo-aligned FFS-type liquid crystal cell manufactured in 1.(3) above, various evaluations of liquid crystal alignment, low-voltage driving, AC image retention characteristics, and liquid crystal response speed were carried out in the same manner as in Example 1. In addition, the adhesion of the sealant was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[0153] [Examples 20 to 31] Photo-aligned FFS-type liquid crystal display elements were manufactured and various evaluations were carried out in the same manner as in Example 19, except that the types of liquid crystal alignment agents used (alignment agent for forming a weak anchoring film and liquid crystal alignment agent for forming a strong anchoring film) were changed as shown in Table 5. The evaluation results are shown in Table 5.

[0154] Comparative Example 3 Photo-aligned FFS-mode liquid crystal display elements were manufactured and evaluated in the same manner as in Example 19, except that the type of liquid crystal alignment agent used was changed as shown in Table 5 and the coating film formed on the opposing substrate was also subjected to photo-alignment treatment. When the pair of substrates was superimposed, the projection directions of the polarization axes of the respective substrates onto the substrate surface during light irradiation were set antiparallel. The evaluation results are shown in Table 5.

[0155] Comparative Example 4 Photo-aligned FFS-type liquid crystal display elements were produced and evaluated in the same manner as in Example 19, except that the type of liquid crystal alignment agent used was changed as shown in Table 5. Note that, as in Example 19, the coating film formed on the opposing substrate was not subjected to photo-alignment treatment. The evaluation results are shown in Table 5.

[0156] [Table 5]

[0157] <Production and evaluation of liquid crystal elements (TN-type liquid crystal display elements)> [Example 33] 1. Liquid crystal display element manufacturing A liquid crystal alignment agent (AL-9) for forming a weak anchoring film was applied to the electrode surface of one of a pair of glass substrates (two substrates) with transparent electrodes made of ITO film using a spin coater, and the substrate was heated on a hot plate at 80°C for 1 minute.Then, the substrate was heated in an oven at 230°C with the interior replaced with nitrogen for 30 minutes, forming a weak anchoring liquid crystal alignment film with an average thickness of 100 nm. A liquid crystal alignment agent (AL-27) for forming a strong anchoring film was applied to the electrode-formed surface of the other of the pair of glass substrates using a spin coater and heated on a hot plate at 80°C for 1 minute. This was then heated in a nitrogen-purged oven at 230°C for 30 minutes to form a coating film with an average thickness of 100 nm. This coating film was then rubbed using a rubbing machine equipped with a roll wrapped around a rayon cloth at a roll rotation speed of 400 rpm, a stage movement speed of 3 cm / sec, and a pile depth of 0.4 mm. The substrate was then ultrasonically cleaned in ultrapure water for 1 minute and then dried in a clean oven at 100°C for 10 minutes to obtain a substrate with a strong anchoring liquid crystal alignment film. An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was applied by screen printing to the outer periphery of the surface of one of the substrates bearing the liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates were placed facing each other, overlapped, and pressed together, and the adhesive was thermally cured by heating at 150°C for 1 hour. Next, a positive liquid crystal (MLC-2055, manufactured by Merck) was filled into the gap between the substrates through the liquid crystal injection port, which was then sealed with an epoxy adhesive. To prevent flow alignment during liquid crystal injection, the substrate was heated at 150°C for 10 minutes and then slowly cooled to room temperature.

[0158] 2. Evaluation Except for using the rubbed alignment TN-type liquid crystal cell manufactured in 1 above, various evaluations of liquid crystal alignment, low-voltage driving, AC image retention characteristics, sealant adhesion, and liquid crystal response speed were carried out in the same manner as in Example 1. The evaluation results are shown in Table 6.

[0159] [Example 34] Rubbed alignment TN-type liquid crystal display elements were manufactured in the same manner as in Example 33, except that the types of liquid crystal alignment agents used (alignment agent for forming a weak anchoring film and liquid crystal alignment agent for forming a strong anchoring film) were changed as shown in Table 6, and various evaluations were performed. The evaluation results are shown in Table 6.

[0160] Comparative Example 5 TN-type liquid crystal display elements were produced and evaluated in the same manner as in Example 33, except that the type of liquid crystal alignment agent used was changed as shown in Table 6 and the coating film formed on the opposing substrate was also subjected to rubbing treatment. When the pair of substrates was superimposed, the rubbing directions of the respective substrates were set perpendicular to each other. The evaluation results are shown in Table 6.

[0161] [Table 6]

[0162] As shown in Tables 5 and 6, in Examples 1 to 34, the liquid crystal alignment, low-voltage driving, AC afterimage characteristics, sealant adhesion, and liquid crystal response speed were all rated as good or fair, and the various characteristics were well-balanced.

[0163] Among these, comparing Example 2, which further blended another polymer, with Example 16, which did not blend another polymer, it was found that blending another polymer improved low-voltage driving and AC image retention characteristics. Furthermore, the examples using an aliphatic crosslinking agent tended to be able to more effectively achieve low-voltage driving of liquid crystal devices and reduce AC image retention than the examples using a crosslinking agent with an aromatic ring (Example 1). Furthermore, the examples using compounds (C-1) to (C-8) or (C-10) as the carboxylic acid introduced into the side chain of the polyorganosiloxane showed a better balance of various properties.

[0164] In contrast, in Comparative Examples 1, 3, and 5, the evaluation of low-voltage driving was "poor." In Comparative Example 2, even after the manufactured liquid crystal cell was heated at 120°C and slowly cooled to room temperature, bright spots due to flow alignment and alignment defects were partially observed, and the evaluation of liquid crystal alignment was "poor." In Comparative Example 2, since the evaluation of liquid crystal alignment was poor, other evaluations were not performed. In Comparative Example 4, the evaluation of AC image retention characteristics was "poor." [Explanation of symbols]

[0165] 10... liquid crystal element, 11... first substrate, 12... second substrate, 13... liquid crystal layer, 14... common electrode, 16... pixel electrode, 21, 22... liquid crystal alignment film

Claims

1. a pair of substrates consisting of a first substrate and a second substrate; a liquid crystal layer containing liquid crystal molecules; Equipped with a weak anchoring liquid crystal alignment film is formed on one of the first substrate and the second substrate, and a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film is formed on the other substrate; The liquid crystal element, wherein the weak anchoring liquid crystal alignment film is formed from a liquid crystal alignment agent containing polyorganosiloxane.

2. 2. The liquid crystal element according to claim 1, wherein the slow axes of the liquid crystal molecules are aligned substantially parallel to the substrate surfaces when the liquid crystal element is not driven.

3. 2. The liquid crystal device according to claim 1, wherein the strong anchoring liquid crystal alignment film is a rubbed alignment film or a photo-alignment film.

4. 2. The liquid crystal device according to claim 1, wherein the polyorganosiloxane has at least one of a cage structure, an incomplete cage structure, and a cyclic structure.

5. The liquid crystal device according to claim 1 , wherein the polyorganosiloxane does not have a photoalignable group.

6. The liquid crystal element according to claim 1, wherein the polyorganosiloxane contains a structural unit represented by the following formula (S-1): 【Chemical 1】 (In formula (S-1), R １ is an alkyl group having 1 to 30 carbon atoms, "*-R ２ -(O-R ３ ) ｒ -OR ４ ", or a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring, which is bonded to a silicon atom via a single bond or a divalent linking group. R ２ and R ３ are each independently an alkanediyl group. r is an integer of 0 or more. ４ is an alkyl group when r is 0, and is a hydrogen atom or an alkyl group when r is 1 or more.

7. 2. The liquid crystal device according to claim 1, wherein the polyorganosiloxane is a cyclic polysiloxane having a molecular weight of 1,500 or less.

8. 2. The liquid crystal device according to claim 1, wherein the polyorganosiloxane does not have a benzene ring.

9. The polyorganosiloxane does not have a partial structure in which two or more cyclohexane rings are bonded by a single bond, -COO-, or -NR- (wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). The liquid crystal element according to claim 1.

10. The liquid crystal device according to claim 1 , wherein the liquid crystal aligning agent further contains a polymer having a main skeleton different from that of the polyorganosiloxane.

11. 2. The liquid crystal device according to claim 1, wherein the weak anchoring liquid crystal alignment film is a film that has not been subjected to alignment treatment.

12. A liquid crystal aligning agent for forming a weak anchoring film, which is used to form a weak anchoring liquid crystal alignment film, and which contains polyorganosiloxane.

13. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, wherein the polyorganosiloxane has at least one of a cage structure, an incomplete cage structure, and a cyclic structure.

14. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, wherein the polyorganosiloxane does not have a photoalignable group.

15. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, wherein the polyorganosiloxane contains a structural unit represented by the following formula (S-1): 【Chemistry 2】 (In formula (S-1), R １ is an alkyl group having 1 to 30 carbon atoms, "*-R ２ -(O-R ３ ) ｒ -OR ４ ", or a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring, which is bonded to a silicon atom via a single bond or a divalent linking group. R ２ and R ３ are each independently an alkanediyl group. r is an integer of 0 or more. ４ is an alkyl group when r is 0, and is a hydrogen atom or an alkyl group when r is 1 or more.

16. The polyorganosiloxane is a polymer having a structural unit represented by the following formula (S-2), and an alkyl group having 1 to 30 carbon atoms, "*-R ２ -(O-R ３ ) ｒ -OR ４ " (wherein R ２ and R ３ are each independently an alkanediyl group, r is an integer of 0 or more, and R ４ is an alkyl group when r is 0, and is a hydrogen atom or an alkyl group when r is 1 or more.) and a carboxylic acid having any one of a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms and one aliphatic hydrocarbon ring. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, 【Chemistry 3】 (In formula (S-2), Y １ is a monovalent group having an epoxy group.

17. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, wherein the polyorganosiloxane is a cyclic polysiloxane having a molecular weight of 1,500 or less.

18. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, wherein the polyorganosiloxane does not have a benzene ring.

19. The polyorganosiloxane does not have a partial structure in which two or more cyclohexane rings are bonded by a single bond, -COO-, or -NR- (wherein R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). A liquid crystal aligning agent for forming a weak anchoring film according to claim 12.

20. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, further comprising a crosslinking agent.

21. The liquid crystal aligning agent for forming a weak anchoring film according to claim 20, wherein the crosslinking agent does not have an aromatic ring.

22. The liquid crystal aligning agent for forming a weak anchoring film according to claim 20, wherein the crosslinking agent has two or more of at least one selected from the group consisting of an oxiranyl group, an oxetanyl group, a cyclic carbonate group, a hydroxy group, a protected hydroxy group, a carboxy group, a protected carboxy group, a mercapto group, a protected mercapto group, an amino group, a protected amino group, a protected isocyanate group, and a polymerizable carbon-carbon unsaturated bond group in one molecule.

23. The liquid crystal aligning agent for forming a weak anchoring film according to claim 12, further comprising a polymer having a main skeleton different from that of the polyorganosiloxane.

24. A step of forming a weak anchoring liquid crystal alignment film on one of the pair of substrates using the liquid crystal aligning agent for forming a weak anchoring film according to any one of claims 12 to 23; forming a strong anchoring liquid crystal alignment film having stronger anchoring energy than the weak anchoring liquid crystal alignment film on the other substrate; A method for manufacturing a liquid crystal element, comprising:

25. The method for manufacturing a liquid crystal device according to claim 24, wherein the strong anchoring liquid crystal alignment film is a rubbed alignment film or a photo-alignment film.

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