Manufacturing method of liquid crystal device

Abstract

To reduce the breakage of transparent substrates when creating a liquid crystal device by arranging a liquid crystal cell between a first and a second transparent substrates.SOLUTION: A manufacturing method for a liquid crystal device 1 is provided in which a liquid crystal cell 10 is arranged between a first transparent substrate 41 and a second transparent substrate 42 smaller in outer shape than the first transparent substrate 41, and the first and second substrates and the liquid crystal cell are integrated into one body. The manufacturing method for the liquid crystal device 1 comprises: an arrangement step of arranging the first transparent substrate 41 in such a manner that the first transparent substrate 41 is located away from and faces the liquid crystal cell 10 laminated on the second transparent substrate 42 on a buffer member 50 which is arranged in the outward of the second transparent substrate 42; and an integration step of contracting the buffer member 50, bringing the first transparent substrate 41 close to the liquid crystal cell 10 and integrating the first transparent substrate 41, the liquid crystal cell 10 and the second transparent substrate 42 into one body.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a liquid crystal device, and can be applied to a process for manufacturing a liquid crystal device by bonding a light control cell (liquid crystal cell) for controlling the amount of transmitted light to a glass plate. [Background technology]

[0002] Conventionally, a configuration has been proposed in which a light-controlling cell (liquid crystal cell) that uses liquid crystal to control the amount of transmitted light is created, and this light-controlling cell (liquid crystal cell) is placed between two transparent substrates and laminated glass to create a liquid crystal device (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 198748 [Patent Document 2] Patent Publication No. 2021-64005 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when creating a liquid crystal device by placing a liquid crystal cell between two transparent substrates made of glass or the like, as the size of the transparent substrate increases, the weight of the transparent substrate also increases, which can cause the transparent substrate to fall and be damaged during the manufacturing process.

[0005] An object of an embodiment of the present disclosure is to provide a manufacturing method for a liquid crystal device that can reduce damage to the transparent substrates when a liquid crystal device is manufactured by disposing a liquid crystal cell between two transparent substrates. [Means for solving the problem]

[0006] The embodiments of the present disclosure solve the above problems by the following solving means. Note that, for ease of understanding, the following description will be given with reference numerals corresponding to the embodiments of the present disclosure, but the present disclosure is not limited thereto.

[0007] (1) A first disclosed embodiment is a method for manufacturing a liquid crystal device (1) including a first transparent substrate (41), a second transparent substrate (42) having an outer shape smaller than that of the first transparent substrate, and a liquid crystal cell arranged between the first transparent substrate and the second transparent substrate, the method comprising the steps of: arranging the first transparent substrate on a buffer member (50) arranged outside the second transparent substrate so as to face and space the liquid crystal cell stacked on the second transparent substrate; and contracting the buffer member to bring the first transparent substrate closer to the liquid crystal cell, thereby integrating the first transparent substrate, the liquid crystal cell, and the second transparent substrate.

[0008] (2) A second disclosed embodiment is a method for manufacturing a liquid crystal device (1) in accordance with (1), in which the integration step is performed by evacuating the atmosphere on the second transparent substrate (42) side of a diaphragm sheet (63) arranged to face the first transparent substrate (41), thereby pressing the diaphragm sheet with atmospheric pressure to contract the buffer member (50).

[0009] (3) A method for manufacturing a liquid crystal device (1) of (1) or (2), comprising a coating step of coating an upper surface of the liquid crystal cell (10) laminated on the second transparent substrate (42) with a bonding material (31A), and in the placement step, a gap is formed between the first transparent substrate (41) placed on the buffer member (50) and the bonding material on the liquid crystal cell. Effect of the Invention

[0010] According to the embodiments of the present disclosure, when a liquid crystal device is fabricated by disposing a liquid crystal cell between glass plates, breakage of the glass plates can be sufficiently reduced. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a liquid crystal device according to an embodiment. [Diagram 2] 1 is a cross-sectional view of a liquid crystal device according to an embodiment. [Diagram 3] 3A to 3C are diagrams illustrating a manufacturing process of the liquid crystal device according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating the continuation of FIG. [Diagram 5] FIG. 5 is a diagram illustrating the continuation of FIG. 4. [Figure 6] 5A to 5C are diagrams illustrating a bonding process of the liquid crystal device according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining the continuation of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing a configuration of a liquid crystal device 1 according to an embodiment of the present disclosure. Note that the figures shown below, including FIG. 1, are schematic views, and the size and shape of each part are appropriately exaggerated to facilitate understanding. In the following description, specific numerical values, shapes, materials, etc. are given, but these can be changed as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel and orthogonal, are intended to include not only their strict meanings but also states that have a similar optical function and have an error that can be regarded as parallel or orthogonal.

[0013] In this specification, the terms plate, sheet, film, etc. are used, and in general usage, they are used in the order of thickness, plate, sheet, film, etc., and this specification follows that order. However, since such distinction in usage has no technical meaning, these terms can be used interchangeably as appropriate. In this specification, the sheet surface refers to the surface of each sheet that is in the planar direction of the sheet when viewed as a whole. The same applies to plate surfaces and film surfaces. In addition, a plan view refers to a state viewed from the normal direction of the sheet surface (plate surface, film surface).

[0014] In the present specification and claims, the term "transparent" refers to a material that transmits at least the light of the wavelength to be used. For example, even if a material does not transmit visible light, if it transmits infrared light, it will be treated as transparent when used for infrared applications. In addition, the specific numerical values ​​specified in the present specification and claims should be treated as including a general margin of error. In other words, a difference of about ±10% means that there is no substantial difference, and values ​​set within a range slightly exceeding the numerical range of the present invention should be interpreted as being substantially within the scope of the present invention.

[0015] The liquid crystal device 1 according to the embodiment of the present disclosure can be applied to various technical fields requiring adjustment of light transmittance, and the scope of application is not particularly limited. The liquid crystal device 1 is disposed in a portion where light control is required, such as window glass of a building, a showcase, an indoor transparent partition, a vehicle window (for example, a front, side, rear, roof window, etc.), a partition board inside a vehicle, etc. This makes it possible to control the amount of light incident on the inside of a building, a vehicle, etc., or to control the amount of light incident on a predetermined area inside a building, a vehicle, etc.

[0016] The liquid crystal device 1 according to the embodiment of the present disclosure may be configured with a three-dimensional shape having a curved surface shape, for example, the liquid crystal device 1 may have a shape that is convex on one side. Note that the liquid crystal device 1 is not limited to this, and may have a planar surface shape (i.e., a flat plate shape), for example. In FIG. 1 and the other figures below, the surface shape is shown as planar for simplicity.

[0017] As shown in FIG. 1, a liquid crystal device 1 according to an embodiment of the present disclosure comprises a first glass plate (first transparent substrate) 41, a first bonding layer 31, a liquid crystal cell 10, a second bonding layer 32, and a second glass plate (second transparent substrate) 42, which are stacked in the thickness direction in the above-mentioned order.

[0018] FIG. 2 is a cross-sectional view showing the layer structure of the liquid crystal device 1 (laminated glass) according to an embodiment of the present disclosure. 2, the liquid crystal device 1 includes a first glass plate 41, a second glass plate 42, and a liquid crystal cell 10 disposed between the first glass plate 41 and the second glass plate 42. The liquid crystal cell 10 includes a first substrate 12, a second substrate 13, and a liquid crystal layer 14 disposed between the first substrate 12 and the second substrate 13.

[0019] The first glass plate (first transparent substrate) 41 and the second glass plate (second transparent substrate) 42 are disposed on the front and back surfaces of the liquid crystal device 1, respectively, and are plate glasses having high light transmittance. In the embodiment of the present disclosure, the first glass plate 41 and the second glass plate 42 have a thickness of 0.5 mm or more and 4 mm or less, and as an example, a plate glass having a thickness of 2 mm is used for both. When inorganic glass is used as the first glass plate 41 and the second glass plate 42, the liquid crystal device 1 can have excellent heat resistance and scratch resistance. The first glass plate 41 and the second glass plate 42 may be subjected to a surface treatment such as a hard coat, if necessary. Instead of inorganic glass, a transparent resin plate, so-called resin glass, may be used for the first glass plate (first transparent substrate) 41 and the second glass plate (second transparent substrate) 42. For example, polycarbonate, acrylic, etc. may be used as the resin glass used for the first transparent substrate and the second transparent substrate. When resin glass is used for the first transparent substrate and the second transparent substrate, the liquid crystal device 1 can be made lighter.

[0020] The first bonding layer 31 is disposed between the first glass plate 41 and the liquid crystal cell 10, and is a member that bonds the first glass plate 41 and the liquid crystal cell 10 to each other. The first bonding layer 31 is larger in size than the liquid crystal cell 10 in a plan view. 2, in cross-sectional view, the first bonding layer 31 is formed not only in the region overlapping the liquid crystal cell 10 but also in a portion corresponding to the periphery of the liquid crystal cell 10, and is connected to the second bonding layer 32 in this portion. Furthermore, in the liquid crystal device 1, a stopper 35 is provided around the first bonding layer 31, and this stopper 35 prevents leakage of the bonding material (OCR material 31A) from the first bonding layer 31 before hardening during the manufacturing process of the liquid crystal device 1. Furthermore, by forming the first bonding layer 31 in this form, it is possible to prevent the side surface or a part thereof of the liquid crystal cell 10 from being exposed to the side surface of the liquid crystal device 1, and also to suppress the intrusion of moisture and the like from the side surface of the liquid crystal device 1, thereby further improving the water-proofing property of the liquid crystal device 1.

[0021] In the embodiment of the present disclosure, the first bonding layer 31 is composed of OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid composition for a curable adhesive layer containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, a silicone resin, or a urethane resin, and an additive, to an object, and then curing the liquid resin using ultraviolet (UV) rays or the like. The first bonding layer 31 has optical transparency, and further preferably has heat resistance up to at least about 120° C., moist heat resistance, and weather resistance. The thickness of the first bonding layer 31 may be appropriately selected depending on the material thereof, etc. Specifically, the thickness of the first bonding layer 31 in the region overlapping with the liquid crystal cell 10 in a plan view may be 30 μm or more and 1000 μm or less. The stopper 35 is made of the same material as the first bonding layer 31, and is formed on the outer edge of the surface of the second bonding layer 32 on the side where the liquid crystal cell 10 is disposed.

[0022] The second bonding layer 32 is disposed between the second glass plate 42 and the liquid crystal cell 10, and is a member that bonds the second glass plate 42 and the liquid crystal cell 10 to each other. The second bonding layer 32 is larger in size than the liquid crystal cell 10 in a plan view. In the embodiment of the present disclosure, the second bonding layer 32 is made of an OCA (Optical Clear Adhesive). The OCA is a layer produced, for example, as follows. First, a liquid composition for a curable adhesive layer containing a polymerizable compound is applied onto a release film such as polyethylene terephthalate (PET), and then cured using, for example, ultraviolet (UV) light to obtain an OCA sheet. The composition for a curable adhesive layer may be an optical pressure-sensitive adhesive such as an acrylic resin, a silicone resin, or a urethane resin. After this OCA sheet is attached to an object, the release film is peeled off and removed to obtain a layer made of the OCA.

[0023] The second bonding layer 32 made of OCA has optical transparency, and further preferably has heat resistance up to at least about 120° C., moist heat resistance, and weather resistance. In the embodiment of the present disclosure, the second bonding layer 32 is described as being made of OCA by way of example, but is not limited thereto, and may be made of OCR like the first bonding layer 31. The thickness of second bonding layer 32 may be appropriately selected depending on the material, etc. Specifically, the thickness of second bonding layer 32 may be 30 μm or more and 500 μm or less, and is preferably 50 μm or more and 200 μm or less.

[0024] In the embodiment of the present disclosure, the first bonding layer 31 directly bonds the first glass plate 41 and the liquid crystal cell 10. Moreover, the second bonding layer 32 directly bonds the second glass plate 42 and the liquid crystal cell 10. Without being limited thereto, for example, a film such as an ultraviolet (UV) cut film may be interposed at least at one location between the first glass plate 41 and the liquid crystal cell 10 and between the second glass plate 42 and the liquid crystal cell 10. As described above, in the embodiment of the present disclosure, the first bonding layer 31 and the second bonding layer 32 are bonded bodies containing a non-compression adhesive component. Here, the term "bonded body containing a non-compression adhesive component" refers to a bonded body that does not require pressure to be properly bonded to an adjacent object and that can be moderately bonded to an adjacent object under normal pressure.

[0025] The liquid crystal cell 10 (light control film, liquid crystal film) is a film that can control the amount of transmitted light by changing the applied voltage. The liquid crystal cell 10 is disposed so as to be sandwiched between a first glass plate 41 and a second glass plate 42. The liquid crystal cell 10 has a guest-host type liquid crystal layer using a dichroic dye, and is a member that changes the amount of transmitted light depending on the electric field applied to the liquid crystal. The liquid crystal cell 10 includes a first substrate 12 in the form of a film, a second substrate 13 in the form of a film, and a liquid crystal layer 14 disposed between the first substrate 12 and the second substrate 13.

[0026] The first substrate 12 and the second substrate 13 each include a first transparent electrode 22A, a second transparent electrode 22B, a first alignment layer 23A, and a second alignment layer 23B. More specifically, the first transparent electrode 22A and the first alignment layer 23A are formed in this order on the surface of the first substrate 12 facing the liquid crystal layer 14, and the second transparent electrode 22B and the second alignment layer 23B are formed in this order on the surface of the second substrate 13 facing the liquid crystal layer 14. Furthermore, a plurality of bead spacers 24 are disposed between the first substrate 12 and the second substrate 13. The liquid crystal layer 14 is filled and disposed between the plurality of bead spacers 24 between the first substrate 12 and the second substrate 13. The plurality of bead spacers 24 may be disposed irregularly or regularly.

[0027] The liquid crystal cell 10 changes the orientation of the liquid crystal material made of a guest-host liquid crystal composition provided in the liquid crystal layer 14 by driving the first transparent electrode 22A and the second transparent electrode 22B provided on the first substrate 12 and the second substrate 13, thereby changing the amount of transmitted light.

[0028] A flexible film made of a transparent resin can be used as the first base material 12 and the second base material 13. As the first base material 12 and the second base material 13, it is desirable to use a transparent resin film having small optical anisotropy and a transmittance of 80% or more in the visible wavelength range (380 nm or more and 800 nm or less). Examples of materials for such transparent resin films include acetylcellulose resins such as triacetylcellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene (PE), polypropylene (PP), polystyrene, polymethylpentene, and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, acrylic resins, polyurethane resins, polysulfone (PSF), polyethersulfone (PES), polycarbonate (PC), polyether (PE), polyether ketone (PEK), (meth)acrylonitrile, cycloolefin polymer (COP), and cycloolefin copolymer resins. Resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are particularly preferred as materials for transparent resin films.

[0029] The thickness of the transparent resin film used as the first base material 12 and the second base material 13 may vary depending on the material, but may be appropriately selected within a range in which the transparent resin film has flexibility. The thickness of the first base material 12 and the second base material 13 may be 50 μm or more and 200 μm or less. In the embodiment of the present disclosure, as an example of the first substrate 12 and the second substrate 13, a polyethylene terephthalate film having a thickness of 125 μm is used.

[0030] The first transparent electrode 22A and the second transparent electrode 22B are each composed of a transparent conductive film laminated on the first substrate 12 and the second substrate 13. As the transparent conductive film, various transparent electrode materials applicable to this type of transparent resin film can be used, and examples thereof include oxide-based transparent metal thin films having a total light transmittance of 50% or more, such as tin oxide-based, indium oxide-based, and zinc oxide-based.

[0031] Tin oxide (SnO2) types include NESA (tin oxide SnO2), ATO (antimony tin oxide), and fluorine-doped tin oxide. Indium oxide (In2O3) types include indium oxide, ITO (indium tin oxide), and IZO (indium zinc oxide). Zinc oxide (ZnO) types include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide. In the embodiment of the present disclosure, the transparent conductive film constituting the transparent electrode is formed of ITO.

[0032] The bead spacers 24 are members that define the thickness (cell gap) of the liquid crystal layer 14 except for the outer periphery. In the embodiment of the present disclosure, spherical bead spacers are used as the bead spacers 24. The diameter of the bead spacers 24 may be 1 μm or more and 20 μm or less, and is preferably 3 μm or more and 15 μm or less. The bead spacer 24 can be made of a wide variety of materials, including inorganic materials such as silica, organic materials, and core-shell structures that combine these materials. In addition to the spherical shape, the bead spacer may be configured in a rod shape such as a cylindrical shape, an elliptical cylindrical shape, a polygonal prism shape, etc. Although the bead spacer 24 is manufactured from a transparent material, a colored material may be applied as necessary to adjust the color.

[0033] In the embodiment of the present disclosure, the bead spacers 24 are provided on the second substrate 13, but the present invention is not limited thereto, and the bead spacers 24 may be provided on both the first substrate 12 and the second substrate 13, or only on the first substrate 12. The bead spacers 24 do not necessarily have to be provided. Instead of the bead spacers 24, or together with the bead spacers 24, columnar spacers may be used.

[0034] The first alignment layer 23A and the second alignment layer 23B are members for aligning liquid crystal molecules contained in the liquid crystal layer 14 in a desired direction. The first alignment layer 23A and the second alignment layer 23B are formed by a photo-alignment layer. As a photo-alignment material applicable to the photo-alignment layer, various materials to which a photo-alignment method can be applied can be widely applied, and examples thereof include a photodecomposition type, a photodimerization type, a photoisomerization type, and the like. In the embodiment of the present disclosure, a photodimerization type material is used. Examples of the photodimerization type material include polymers having cinnamate, coumarin, benzylidenephthalimidine, benzylideneacetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or cinnamylideneacetic acid derivatives. As the photodimerization type material, a polymer having one or both of cinnamate and coumarin is preferably used, in particular because of its good alignment control force.

[0035] In addition, a rubbing alignment layer may be used instead of the photo-alignment layer. The rubbing alignment layer may not be subjected to a rubbing treatment, or may be subjected to a rubbing treatment and then subjected to a shaping treatment to form fine line-shaped irregularities to prepare the alignment layer. In the embodiment of the present disclosure, the liquid crystal cell 10 includes an alignment layer on each of the first substrate 12 and the second substrate 13, but is not limited thereto, and may have a configuration that does not include an alignment layer.

[0036] A wide variety of guest-host liquid crystal compositions and dichroic dye compositions can be used for the liquid crystal layer 14. The guest-host liquid crystal composition may contain a chiral agent so that the liquid crystal material is aligned in a helical shape in the thickness direction of the liquid crystal layer 14 when the liquid crystal material is aligned horizontally. A sealant 25 having a ring or frame shape in plan view is disposed between the first substrate 12 and the second substrate 13 so as to surround the liquid crystal layer 14. The sealant 25 holds the first substrate 12 and the second substrate 13 together and prevents leakage of the liquid crystal material. The sealant 25 may be a thermosetting resin such as an epoxy resin or an acrylic resin, or an ultraviolet-curable resin.

[0037] For the liquid crystal layer 14, a nematic liquid crystal compound, a smectic liquid crystal compound, or a cholesteric liquid crystal compound can be used as a liquid crystal compound having no polymerizable functional group. Examples of nematic liquid crystal compounds include biphenyl-based compounds, terphenyl-based compounds, phenylcyclohexyl-based compounds, biphenylcyclohexyl-based compounds, phenylbicyclohexyl-based compounds, trifluoro-based compounds, phenyl benzoate-based compounds, phenyl cyclohexylbenzoate-based compounds, phenyl benzoate-based compounds, phenyl bicyclohexylcarboxylate-based compounds, azomethine-based compounds, azo-based compounds, azooxy-based compounds, stilbene-based compounds, tolane-based compounds, ester-based compounds, bicyclohexyl-based compounds, phenylpyrimidine-based compounds, biphenylpyrimidine-based compounds, pyrimidine-based compounds, and biphenylethyne-based compounds.

[0038] Examples of the smectic liquid crystal compound include ferroelectric polymer liquid crystal compounds such as polyacrylates, polymethacrylates, polychloroacrylates, polyoxiranes, polysiloxanes, and polyesters. Examples of the cholesteric liquid crystal compound include cholesteryl linoleate, cholesteryl oleate, cellulose, cellulose derivatives, and polypeptides.

[0039] Dichroic dyes used in the guest-host system include dyes that are soluble in liquid crystal and have high dichroic properties, such as azo-based, anthraquinone-based, quinophthalone-based, perylene-based, indigo-based, thioindigo-based, merocyanine-based, styryl-based, azomethine-based, and tetrazine-based dichroic dyes.

[0040] The liquid crystal cell 10 is configured as a normally dark cell by configuring the first alignment layer 23A and the second alignment layer 23B as horizontal alignment layers with an alignment restraining force related to the pretilt in a certain direction so that the alignment of the guest-host liquid crystal composition during light shielding is formed during the absence of an electric field. Note that the liquid crystal cell 10 may be configured as a normally clear cell by configuring the liquid crystal cell 10 during light shielding as a normally clear cell during the application of an electric field. Normally dark is a structure in which the transmittance is at a minimum when no voltage is applied to the liquid crystal, resulting in a black screen, whereas normally clear is a structure in which the transmittance is at a maximum when no voltage is applied to the liquid crystal, resulting in a transparent screen.

[0041] In addition, since it is desirable that the scenery or the like seen through the liquid crystal cell 10 be clearly visible when light is transmitted, it is desirable that the haze value when light is transmitted is low. Specifically, the haze value of the liquid crystal cell 10 when light is transmitted is desirably 30% or less, and more desirably 15% or less. In order to achieve such a low haze value, it is desirable that the liquid crystal mixture does not contain a polymerizable compound.

[0042] The liquid crystal cell 10 according to the embodiment of the present disclosure is shown as an example having a guest-host type liquid crystal layer 14, but is not limited thereto. The liquid crystal cell 10 may be configured to have a liquid crystal layer 14 of a TN (Twisted Nematic) type, a VA (Vertical Alignment) type, an IPS (In-Plane-Switching) type, or the like that does not use a dichroic dye composition. When such a liquid crystal layer 14 is provided, it can function as a light control film by further providing a linear polarization layer on each of the surfaces of the first substrate 12 and the second substrate 13.

[0043] As shown in FIG. 1, a flexible printed wiring board 18 is disposed on the liquid crystal cell 10 in order to electrically connect the transparent electrodes to the outside.

[0044] (manufacturing process) Next, a method for manufacturing the liquid crystal device 1 according to the embodiment of the present disclosure will be described with reference to FIGS. 3 to 5 are diagrams illustrating a method for manufacturing the liquid crystal device 1 according to the embodiment of the present disclosure. In FIG. 3 to FIG. 5, the manufacturing method is explained with reference to cross-sectional views of the liquid crystal device 1.

[0045] First, as shown in FIG. 3(a), a second glass plate 42 is prepared.

[0046] 3(b), a second bonding layer 32 made of OCA is bonded onto a second glass plate 42. In this case, for example, an OCA sheet having the second bonding layer 32 and a release film 36 is bonded to the second glass plate 42, and then the release film 36 is peeled off and removed, thereby bonding the second bonding layer 32 onto the second glass plate 42. The second bonding layer 32 may be bonded to the entire area of ​​one side of the second glass plate 42, or may be bonded to a partial area. In the above description, an example is shown in which an OCA sheet is used as the second bonding layer 32, but the present invention is not limited thereto. For example, the second bonding layer 32 may be formed by applying an OCR material onto the second glass plate 42 and temporarily curing the OCR material. Here, temporarily curing refers to a state in which the OCR material is not completely cured and the adhesiveness of the OCR material is maintained to a certain degree. The amount of ultraviolet (UV) radiation applied at this time is less than the amount of radiation applied when the OCR material 31A (first bonding layer 31) is completely cured, and may be, for example, 50% to 80%.

[0047] 3(c), a liquid crystal cell 10 prepared separately is bonded onto the second bonding layer 32, and the liquid crystal cell 10 is bonded to the second glass plate 42 by the second bonding layer 32. Note that the liquid crystal cell 10 can be manufactured by various known methods. The second bonding layer 32 made of OCA is a bonding body containing a non-pressure-bonding adhesive component as described above. Therefore, the liquid crystal cell 10 and the second glass plate 42 are bonded without pressure (i.e., under environmental pressure (usually atmospheric pressure)). In addition, the second bonding layer 32 is bonded to the liquid crystal cell 10 and the second glass plate 42 at room temperature (for example, 10°C or higher and 30°C or lower).

[0048] 3(d), a stopper 35 is formed on the outer edge of the second bonding layer 32 on the second glass plate 42 so as to surround the outer periphery of the liquid crystal cell 10 at a distance from the liquid crystal cell 10. The stopper 35 is formed by applying a liquid OCR material containing OCR using an application nozzle 51 and then curing the OCR material by irradiation with ultraviolet light.

[0049] 4(a), a liquid OCR material (bonding material) 31A containing OCR relating to the first bonding layer 31 is applied to the upper surface of the liquid crystal cell 10 (application step). A buffer member 50 is also arranged outside the second glass plate 42. More specifically, the buffer member 50 formed in a frame shape is arranged so as to surround the outer periphery of the second glass plate 42. Here, the OCR material (bonding material) 31A is applied to the entire area or a partial area of ​​one side of the liquid crystal cell 10 and the adjusting member 20 by an application nozzle 51 such as a dispenser or a slit coater. Then, as shown in FIG. 4(b), the first glass plate 41 is placed on the buffer member 50 (placement step). Each step shown in FIG. 4 is performed on a bonding apparatus 60 which will be described later.

[0050] The buffer member 50 is provided to dispose the first glass plate 41 in a spaced-apart state from the liquid crystal cell 10 disposed on the second glass plate 42 for an integration process using a bonding apparatus described later. Therefore, in the manufacturing process of the liquid crystal device 1, the outer dimensions (length and width) of the first glass plate 41 are formed to be larger than those of the second glass plate 42. In other words, the outer dimensions (length or width, or length and width) of the second glass plate 42 are formed to be smaller than those of the first glass plate 41. As a result, as shown in FIG. 4(b), the first glass plate 41 can be disposed on the laminate made up of the second glass plate , the second bonding layer 32, and the liquid crystal cell , with the buffer member 50 interposed therebetween.

[0051] Here, the thickness of the buffer member 50 is desirably formed so that the first glass plate 41 does not come into contact with the OCR material 31A applied on the liquid crystal cell 10, and for example, the gap G between the OCR material 31A and the first glass plate 41 is desirably 100 μm or more. By providing a gap between the OCR material 31A and the first glass plate 41 in this manner, it is possible to significantly prevent air (air bubbles) from remaining in the first bonding layer 31 that is formed when a vacuum is drawn by a bonding device in the integration process described below.

[0052] As described above, the cushioning member 50 of the present embodiment is exemplified as being formed in a frame shape surrounding the outer periphery of the second glass plate 42, but is not limited thereto. As long as it is sufficient for practical use, the cushioning member 50 may be formed in a shape including a partially interrupted portion, may be provided only at the corner portion of the first glass plate 41, or may be provided only at the straight portion of the first glass plate 41, and may be formed in various shapes. Furthermore, when the first glass plate 41 is placed on the cushioning material 50 as shown in FIG. 4(b), it is desirable to arrange it so that the width D of the portion that overlaps with the cushioning material 50 is, for example, 50 mm or more, although this depends on the external dimensions of the liquid crystal device 1.

[0053] The cushioning member 50 can be made of polyurethane foam, polyester, or the like, and is formed so that it can shrink sufficiently when pressed by a diaphragm sheet in a bonding device described later, thereby holding the first glass plate 41 close to the liquid crystal cell 10.

[0054] Next, as shown in FIG. 4(c), the cushioning material 50 is contracted by pressing the diaphragm sheet with a bonding device described later, bringing the first glass plate 41 closer to the liquid crystal cell 10, and integrating the first glass plate 41, the liquid crystal cell 10, and the second glass plate 42 (integration process). As described above, the OCR material 31A is a liquid OCR material containing OCR, and is a bonding material containing a non-pressure-bonding adhesive component. Therefore, the first glass plate 41 is bonded to the liquid crystal cell 10 under environmental pressure (usually atmospheric pressure) without being pressurized. In addition, the first glass plate 41 is bonded to the liquid crystal cell 10 and the second bonding layer 32 of the second glass plate 42 at room temperature (for example, 10° C. or higher and 30° C. or lower). Here, by pressing the diaphragm sheet, the OCR material 31A flows over the liquid crystal cell 10 and takes the form of the first bonding layer 31. Furthermore, the flowed OCR material 31A is largely prevented from leaking out to the outer periphery of the second bonding layer 32 by the stopper 35 provided on the outer edge of the second bonding layer 32.

[0055] 5(a), the laminated second glass plate 42, second bonding layer 32, liquid crystal cell 10, layer of OCR material 31A, and first glass plate 41 are taken out of the laminating device and irradiated with ultraviolet (UV) light to harden the layer of OCR material 31A. As the layer of OCR material 31A hardens, the first bonding layer 31 made of OCR is formed.

[0056] Thereafter, as shown in FIG. 5(b), the cushioning material 50 is removed, and the first glass plate 41 is cut to the same size as the second glass plate 42 along the cutting line LL, thereby obtaining the liquid crystal device 1. In the above explanation, the first glass plate 41 is described as being cut to the size of the second glass plate 42, but it is not necessary to cut it to the size of the second glass plate 42 if necessary, and it is also not necessary to cut it to match the size of the second glass plate 42.

[0057] [Laminating device] In the liquid crystal device 1 , a first glass plate 41 is bonded to a laminate of a second glass plate 42 and a liquid crystal cell 10 by a bonding apparatus 60 . 6 and 7 are cross-sectional views showing this lamination apparatus. As shown in FIG. 6(a), the laminating device 60 includes a table 61 on which the lamination objects are placed. Furthermore, the laminating device 60 is formed so that an upper case 62 is held so as to be freely opened and closed with respect to the table 61, and the upper case 62 covers and conceals the table 61 together with the lamination objects from above, and is sealed. The laminating device 60 is formed so that the internal space of the upper case 62 is divided by a diaphragm sheet 63 into a table side space AR1 close to the table 61 and an anti-table side space AR2 farther from the table 61, and the atmosphere in the table side space AR1 and the anti-table side space AR2 can be exhausted. The diaphragm sheet 63 is a sheet material having sufficient flexibility, and is formed of, for example, silicon.

[0058] As shown in Fig. 6(a), in the bonding device 60, a laminate including the second glass plate 42, the second bonding layer 32, the stopper 35, and the liquid crystal cell 10 is placed on a table 61 together with a cushioning member 50. In addition, an OCR material 31A for the first bonding layer 31 is applied to the liquid crystal cell 10 of the laminate (application step: Fig. 4(a)). Thereafter, the first glass plate 41 is disposed on the cushioning member 50 (disposing step, FIG. 4(b)).

[0059] 6(b), the objects to be bonded are covered from above by the upper case 62, sealing them inside the bonding device 60. In this state, the bonding device 60 evacuates the atmosphere from the table side space AR1 and the anti-table side space AR2 and is held in a vacuum state, whereby the diaphragm sheet 63 is held close to the upper surface of the first glass plate 41 and faces this upper surface approximately parallel to it.

[0060] Here, in the past, in the bonding device, the first glass plate was attached to the table side surface of the diaphragm sheet using double-sided tape or the like without using the above-mentioned cushioning member. Then, by closing the upper case, the first glass plate attached to the diaphragm sheet was placed on the liquid crystal cell, and the integration process was carried out. However, as the liquid crystal device became larger, the first glass plate also became larger, and the weight of the first glass plate could cause the first glass plate attached to the diaphragm sheet to fall, resulting in problems such as damage to the first glass plate. Therefore, in the present embodiment, as described above, by providing a cushioning member 50 and placing the first glass plate 41 on top of the cushioning member 50, it is possible to prevent the first glass plate from falling from the diaphragm sheet and becoming damaged, etc., as described above.

[0061] Next, as shown in FIG. 7(a), the table side space AR1 is maintained in a vacuum state, while the vacuum state of the counter table side space AR2 is returned to atmospheric pressure. As the counter table side space AR2 returns from a vacuum state to atmospheric pressure, the diaphragm sheet 63 deforms, and as shown in FIG. 7(b), the diaphragm sheet 63 deforms into a shape following the surface shape of the laminate of the first glass plate 41, the liquid crystal cell 10, and the second glass plate 42 arranged on the table 61, and presses the laminate of the first glass plate 41, the liquid crystal cell 10, and the second glass plate 42 with atmospheric pressure. At this time, the cushioning member 50 contracts due to the pressure of the diaphragm sheet 63, and the first glass plate 41 is bonded to the liquid crystal cell 10 side via the OCR material 31A. At this time, the side surface of the cushioning member 50 also contracts to match the outer shape of the first glass plate 41. After the first glass plate 41 is bonded to the liquid crystal cell 10 without any gaps by the OCR material 31A using the bonding device 60, the laminate of the first glass plate 41, the liquid crystal cell 10, and the second glass plate 42 is removed from the bonding device 60 and irradiated with ultraviolet light as described above with reference to Fig. 5(a) to form the first bonding layer 31. Finally, as described above with reference to Fig. 5(b), the excess portion of the first glass plate 41 is cut off to complete the liquid crystal device 1. The irradiation of ultraviolet light may be performed while the plate is held on the table 61 of the bonding device 60.

[0062] According to the above configuration, by providing a buffer member 50 on the outside of the second glass plate 42 and positioning and bonding the first glass plate 41 on this buffer member 50, it is possible to reduce damage to the glass plates when a liquid crystal device is created by placing a liquid crystal cell between the first and second glass plates.

[0063] Furthermore, in the bonding apparatus 60, the atmosphere on the second glass plate 42 side of the diaphragm sheet 63 is evacuated, and the diaphragm sheet 63 is pressed by atmospheric pressure to contract the buffer member 50, thereby effectively avoiding localized pressure concentration and appropriately contracting the buffer member, thereby reducing damage to the glass plates.

[0064] Furthermore, since a gap is formed between the first glass plate 41 placed on the buffer member 50 in the placement process and the OCR material 31A on the liquid crystal cell 10, when a vacuum is drawn using a bonding device in the integration process, it is possible to significantly prevent air (air bubbles) from remaining in the first bonding layer 31 to be formed.

[0065] Other Embodiments The above describes in detail specific configurations suitable for implementing the present invention. However, the present invention allows the configurations of the above-described embodiments to be modified in various ways and even combined in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0066] 1 Liquid crystal device 10 Liquid crystal cell 14 Liquid crystal layer 24 Bead Spacer 25 Sealing material 31 1st bonding layer 31A OCR material 32 Second bonding layer 35 Stopper 36 Release film 41 First Glass Pane 42 Second Glass Pane 50 Cushioning material 51 Application nozzle 60 Laminating device 61 Table 62 Upper case 63 Diaphragm sheet

Claims

1. A method for manufacturing a liquid crystal device including a first transparent substrate, a second transparent substrate having an outer shape smaller than that of the first transparent substrate, and a liquid crystal cell disposed between the first transparent substrate and the second transparent substrate, comprising: a positioning step of positioning the first transparent substrate on a buffer member disposed outside the second transparent substrate so as to face the liquid crystal cell laminated on the second transparent substrate at a distance; and an integration step of: contracting the buffer member to bring the first transparent substrate closer to the liquid crystal cell, and integrating the first transparent substrate, the liquid crystal cell, and the second transparent substrate. A method for manufacturing a liquid crystal device.

2. The integration step includes: By exhausting the atmosphere on the second transparent substrate side of a diaphragm sheet disposed so as to face the first transparent substrate, the diaphragm sheet is pressed by atmospheric pressure to contract the buffer member. A method for manufacturing the liquid crystal device according to claim 1 .

3. a coating step of coating a bonding material on an upper surface of the liquid crystal cell laminated on the second transparent substrate; A gap is formed between the first transparent substrate placed on the buffer member in the placing step and the bonding material on the liquid crystal cell. A method for manufacturing the liquid crystal device according to claim 1 or 2.

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