WO2010110049A1 - Photocurable composition for liquid crystal display panel seal, and liquid crystal display panel - Google Patents

Abstract

Disclosed is a photocurable composition for a liquid crystal display panel seal, which is characterized by containing a nonionic surfactant having an HLB value of 10 or more in an amount of 0.1 to 4% by mass relative to the total solid content of the photocurable composition. The nonionic surfactant is preferably an alkylene oxide-modified polydimethyl siloxane. The photocurable composition has excellent electrical properties and excellent adhesiveness, particularly excellent adhesiveness to a liquid crystal cell substrate that comprises a material composed of a plastic and having an SiOx, SiNx or ITO electrode on the surface thereof.

Description

Photocurable composition for liquid crystal display panel seal and liquid crystal display panel

The present invention relates to a photocurable composition for liquid crystal display panel seals, and more particularly to a photocationic curable photocurable composition for liquid crystal display panel seals.

In general, a liquid crystal display panel is configured such that a rear substrate including a thin film transistor, a pixel electrode, an alignment film, and the like is opposed to a front substrate including a color filter, an electrode, an alignment film, and the like, and liquid crystal is sealed between the substrates. . A sealing agent is used for the purpose of bonding the two substrates.

In recent years, in order to reduce the thickness and weight of liquid crystal display panels, or to provide flexibility, it has been studied to replace the material of both the front substrate and the front and rear substrates from conventional glass to plastic. However, most of the conventionally used sealing agents have been developed for glass, and it has been difficult to divert as they are. When a thermosetting sealant composed mainly of an epoxy-based thermosetting resin is used, it is often cured at 150 degrees, but substrates with different temperature differences between the upper and lower substrates or different thermal expansion coefficients are attached to each other. When combined, there is a problem that the liquid crystal display panel bends when the panel is cooled to room temperature. In order to avoid this, a method of adding a curing catalyst such as an inorganic solid acid such as silica or an organic acid such as salicylic acid to an epoxy resin and performing a curing reaction at a low temperature of 40 ° C. or less (for example, patent) However, it takes a long time to cure and is not practical.

On the other hand, a photocurable sealant mainly composed of acrylate or the like (for example, see Patent Document 2) is suitable for plastic substrates because it does not require heat for curing and can be cured in a short time. However, since acrylate has a large cure shrinkage, its adhesiveness is weak and it may be peeled off by a simple impact or the like. Also known is a photo-thermosetting sealant that uses a photo-curing component and a thermo-curing component together, first semi-cured by photo-curing, and then fully cured by heating (usually using heating during annealing). However, (for example, Patent Documents 3 to 6), the adhesiveness to the plastic substrate is still weak and there is a problem in practical use.
On the other hand, a photo-curable sealing agent having a light binary curing system (for example, see Patent Document 7) that uses a photo-cationic curable material mainly composed of epoxy or the like and a photo-radical curable acrylate, etc. It is not necessary and not only can be cured in a short time, but also the adhesion to the organic protective layer and SiOx can be greatly improved by utilizing the photo-ring-opening reaction. However, the adhesiveness to the surface of SiNx or ITO electrode substrate is weak, and there is a problem that usable substrates are limited.

JP 11-153800 A JP 2005-171135 A JP-A-5-295087 JP-A-2005-18022 JP 2006-23582 A Japanese Patent Laid-Open No. 3-188186 JP 2008-96575 A

The problem to be solved by the present invention is superior to a substrate for a liquid crystal cell having excellent electrical properties and adhesiveness, particularly a substrate made of plastic and having a base material having a SiOx, SiNx, ITO electrode as an adhesive surface. Another object of the present invention is to provide a photocurable composition for sealing a liquid crystal display panel having high adhesiveness.

The present inventors solved the above problems by adding a small amount of a nonionic surfactant to the photocurable composition for sealing a liquid crystal display panel.
Since surfactant has the ability to reduce surface tension, it mainly has wettability, permeability, spreadability, foam stability, fluidity, leveling, defoaming, emulsification, dispersibility, and water and oil repellency. It is an additive used for the purpose of imparting or improving. The present inventors have found that a specific surfactant can enhance the adhesion of the liquid crystal sealant and does not decrease the voltage holding ratio.

That is, the present invention provides a photocurable composition for sealing a liquid crystal display panel comprising 0.1 to 4% by mass of a nonionic surfactant having an HLB value of 10 or more based on the total amount of the solid content of the photocurable composition. .

The present invention also provides a liquid crystal display panel using the above-mentioned photocurable composition for sealing a liquid crystal display panel.

According to the present invention, it has excellent electrical properties and adhesiveness, and in particular has excellent adhesiveness to a liquid crystal cell substrate having a base material made of plastic and having an SiOx, SiNx, ITO electrode as an adhesive surface. A photocurable composition for liquid crystal display panel seals is obtained.

(Nonionic surfactant)
As the nonionic surfactant used in the present invention, for example, a higher alcohol, a higher amine, a higher fatty acid, or a silicone main chain having an alkylene oxide added thereto can be used. Specifically, for example, polyoxyethylene alkyl ether, polyoxyethylene / propylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, polyoxyethylene sterol, polyoxyethylene hydrogenation Sterol, polyoxyethylene alkylphenyl formaldehyde condensate, polyethylene glycol fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene alkyl ether acetic acid, etc. More preferably, alkylene such as alkylene oxide modified polydimethylsiloxane Kishido modified silicone surfactants are preferred because it does not lower the better and voltage holding ratio in potentiation of the adhesive.
Specifically, the silicone surfactant represented by the general formula (1) in which an alkylene oxide is added to the silicone main chain is more preferable because a particularly excellent adhesive property can be imparted even when a small amount is added.

（１）

(1)

In the general formula (1), R represents a hydrogen atom, a butyl group, or an acetyl group, x, y, z, a, and b represent integers of repeating units, x is 0 ≦ x ≦ 50, and y is 1 ≦ y ≦ 10, z is 0 ≦ z ≦ 10, a is 1 ≦ a ≦ 200, and b is 0 ≦ b ≦ 100.

Especially, it is more preferable that a which is the number of repeating units of the ethylene oxide chain in the general formula (1) is a ≦ 100. By setting a ≦ 100, a hydrophobic part and a hydrophilic part are appropriately mixed in the nonionic surfactant represented by the general formula (1). .

The nonionic surfactant may have an epoxy group. Having an epoxy group is more preferable because it is incorporated into the structure of the curable composition by photocationic curing and works advantageously on adhesion.

Commercially available products can be used as the nonionic surfactant, such as “BT” series manufactured by Nikko Chemicals, “Nonipol” series manufactured by Sanyo Kasei Co., Ltd., “D-” “P-” manufactured by Takemoto Yushi Co., Ltd. Series, Air Products' "Surfinol" series, Nissin Chemical's "Orphine" series, Nippon Emulsion's "EMALEX DAPE" series, Toray Dow Corning and Shin-Etsu Chemical's polyether modified Silicone or the like can be used.

In the present invention, the nonionic surfactant has an HLB value of 10 or more. Of these, 11 to 14 is most preferable. If the HLB value is less than 10, the adhesion to the SiOx, ITO and SiNx surfaces tends to be lost. On the other hand, if the HLB value exceeds 15, adverse effects on the electrical characteristics are likely to occur.
The HLB value is used as an index representing the hydrophilicity and lipophilicity of the surfactant, and several calculation methods have been proposed. For example, the nonionic surfactant HLB value is represented by the following formula:

Can be defined.

The nonionic surfactant is added in a very small amount to the photocurable composition for sealing a liquid crystal display panel of the present invention (hereinafter sometimes abbreviated as “photocurable composition for sealing”), so that SiOx, SiNx. In addition, since it is exerted on a base material having an ITO electrode as an adhesive surface, a plastic liquid crystal cell substrate provided with these members can be satisfactorily adhered. In order to further increase the adhesive strength, the addition amount is preferably in the range of 0.1 to 4.0% by mass with respect to the total solid content of the photocurable composition for sealing of the present invention, preferably 0.1 to 2%. 0.0 mass% is most preferable. If the amount is too large, elution into the liquid crystal occurs, and the electrical characteristics are affected, such as a decrease in voltage holding ratio, which is not preferable.

(Photocurable composition for liquid crystal display panel seals)
The curing form of the photocurable composition for sealing a liquid crystal display panel of the present invention may be any of radical photocuring system, cationic photocuring system, or a combination of these, cationic photocuring system or radical photocuring system. And a cationic photocuring system are preferred because they are excellent in the balance between light-curing property and adhesion to a substrate having SiOx, SiNx, or ITO on the surface, and the effects of the present invention can be exhibited more.

(Cationic photocuring composition)
A cationic photocurable composition (hereinafter referred to as a cationic photocurable composition) is a composition comprising a cationic polymerizable compound and a cationic photopolymerization initiator. The cationically polymerizable compound is not particularly limited as long as it is a known and commonly used compound having an epoxy group, an oxetanyl group, or a vinyl ether group, which is generally used in the field of UV curing. However, a compound having an oxetanyl group is preferably used only in a small amount because it is disadvantageous in adhesiveness to a plastic substrate that is largely deformed compared to a glass substrate because the amount of hydroxyl groups produced by polymerization is small. .

Examples of the cationically polymerizable compound having one or more epoxy groups in one molecule include bisphenol A type epoxy resins (trade names “Epicron 850CRP”, “Epicron 850S”, “Epicron 1050”, “Epicron” manufactured by DIC Corporation). 1055 "), bisphenol F-type epoxy resin (trade names" Epicron 830CRP "and" Epicron 830 "manufactured by DIC, bisphenol S-type epoxy resin (trade name" Epicron EXA1514 "manufactured by DIC)), hydrogenated bisphenol-type epoxy resin (Trade name “Epicron EXA7015” manufactured by DIC Corporation), propylene oxide-added bisphenol A type epoxy resin (trade name “EP-4000S” manufactured by Asahi Denka Co., Ltd.), resorcinol type epoxy resin (trade name “manufactured by Nagase ChemteX Corporation” EX-201 ), Biphenyl type epoxy resin (trade name “Epicoat YX-4000H” manufactured by Japan Epoxy Resin), dicyclopentadiene type epoxy resin (trade name “EP-4088S” manufactured by Asahi Denka Co., Ltd.), naphthalene type epoxy resin (DIC) Trade name “Epicron HP4032”, “Epicron EXA-4700”) phenol novolac type epoxy resin (trade name “Epicron N-770” made by DIC), orthocresol novolak type epoxy resin (trade name made by DIC) “Epicron N-670-EXP-S”), NC-3000P (Nippon Kayaku Co., Ltd.) and other biphenyl novolac epoxy resins, ESN-165S (Toto Kasei Co., Ltd.) naphthalene phenol novolac epoxy resins, Epicoat 630 (Japan Epoxy Resin) Modified epoxy resin (trade name “PB3600” manufactured by Daicel Chemical Industries, Ltd.), bisphenol A type episulfide resin (trade name “Epicoat YL-7000” manufactured by Japan Epoxy Resin Co., Ltd.), etc. Alicyclic epoxy resin ( Trade name “Celoxide 2021”, “Celoxide 2080”, “Celoxide 3000”, “EHPE”) manufactured by Daicel Chemical Industries, Ltd.).

Examples of commercially available cationically polymerizable compounds having one or more vinyl ether groups include 4-vinyloxybutanol (trade name “Vinyl-4-hydroxybutyether” manufactured by BASF) and triethylene glycol divinyl ether (manufactured by ISP). Trade name “Rapi-Cure DVE-3”), 1,4-cyclohexanedimethanol divinyl ether (trade name “CHDVE” manufactured by Nippon Carbide Industries, Ltd.), and the like.

Examples of the cationically polymerizable compound having one or more oxetanyl groups in one molecule include 3-ethyl-3- (phenoxymethyl) oxetane (trade name “OXT-211” manufactured by Toagosei Co., Ltd.), 3-ethyl -3- (cyclohexyl) methyloxetane (trade name “CHOX” manufactured by Toa Gosei Co., Ltd.) and the like. Examples of the compound having two or more oxetane rings include 1,4-bis [{(3-ethyloxetane-1-yl) methoxy} methyl] benzene (trade name “OXT-121” manufactured by Toagosei Co., Ltd.), 1,3 -Bis [(3-ethyloxetane-3-yl) methoxy] benzene (trade name “OXT-223” manufactured by Toa Gosei Co., Ltd.), bis [1-ethyl (3-oxetanyl)] methyl ether (product of Toa Gosei Co., Ltd.) Name “OXT-221”), phenol novolac oxetane (trade name “PNOX-1009” manufactured by Toa Gosei Co., Ltd.), 4,4′-bis [{(3-ethyloxetane-1-yl) methoxy} methyl] biphenyl (Ube) Product name “OXBP” manufactured by Kosan Co., Ltd.).

Among the cationic polymerizable compounds, a polymerizable compound having an epoxy group having an aromatic ring is particularly preferable because cohesive force is obtained by utilizing the interaction between aromatic rings, which is advantageous for adhesion. Specifically, bisphenol A type epoxy resin (trade names “Epicron 850CRP”, “Epicron 850S”, “Epicron 1050”, “Epicron 1055” manufactured by DIC), bisphenol F type epoxy resin (trade names manufactured by DIC) "Epicron 830CRP", "Epicron 830") and the like.
Since the viscosity is particularly low and the dilution effect with the compound represented by the general formula (1) is high, bisphenol A type epoxy resin (trade name “Epiclon 850CRP” manufactured by DIC) and bisphenol F type epoxy resin (manufactured by DIC) (Trade name "Epiclon 830CRP") is particularly preferred.

Examples of the cationic photopolymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts. When the cationic photopolymerization initiator is used, the preferable lower limit of the wavelength range of the irradiated light is 300 nm, and the preferable upper limit is 420 nm.
Among these onium salts, commercially available products include, for example, Optomer SP-150, Optomer SP-151, Optomer SP-170, Optomer SP-171 (all manufactured by Asahi Denka Kogyo Co., Ltd.), UVE-1014 (General Electronics Co., Ltd.), Irgacure-261 (Ciba Geigy), Sun-Aid SI-60L, Sun-Aid SI-80L, UVI-6990 (Union Carbide), BBI-103, MPI-103, TPS-103, MDS-103, DTS-103, NAT-103, NDS-103 (all manufactured by Midori Chemical Co., Ltd.), Sun-Aid SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CI-2064, CI-2639, CI-2624, CI-2481 (Both made by Nippon Soda Co., Ltd.), RHODORSIL HOTOINITIATOR 2074 (manufactured by Rhone-Poulenc), CD-1012 (manufactured by Sartomer Company, Inc.), and the like. Among these, optomer SP-150 is more preferable because it hardly causes electrode corrosion due to an onium salt and can easily obtain effective curability.

The cationic photopolymerization initiator may be used alone or in combination of two or more. Moreover, you may use together sensitizers, such as anthracene type and a thioxanthone type, as needed. The proportion of the cationic photopolymerization initiator is not particularly limited, but it is usually used within the range of 0.1 to 10% by mass with respect to the total amount of the cationic polymerizable compound. If it is less than 0.1% by mass, the curability of the sealing agent of the present invention may be insufficient, and if it exceeds 10% by mass, a cationic photopolymerization initiator that cannot be reacted can remain and dissolve into the liquid crystal. There is sex. Among these, 0.3 to 3% by mass is preferable.

(Radical photocuring composition)
A radical photocurable composition (hereinafter referred to as a radical photocurable composition) is a composition comprising a radical polymerizable compound and a radical photopolymerization initiator. The radically polymerizable compound is not particularly limited as long as it is a known and commonly used compound having a (meth) acryloyl group as commonly used in the field of UV curing, but when used as a liquid crystal display panel seal Those that are difficult to mix with liquid crystal can be used more preferably. However, in order to avoid excessive curing shrinkage, it is preferable to use only a small amount of (meth) acrylate such as dipentaerythritol penta, hexaacrylate, pentaerythritol tetraacrylate and the like, which are considered to have large curing shrinkage. Moreover, since the radically polymerizable compound which has a carboxylic acid group may react with an epoxy group during storage and may increase the viscosity of the composition rapidly, it is preferable to use only a small amount.

Modified with polyester (meth) acrylate, epichlorohydrin, which is called “photopolymerizable oligomer” in the field of UV curing, has an ester bond in the main chain structure and has at least two (meth) acryloyl groups Epoxy (meth) acrylate, ethyl oxide, propylene oxide, (meth) acrylate modified with cyclic lactone, and the like obtained in this manner can also be preferably used. However, when an acrylate having a urethane group is used in combination with a cationic curing system, curing inhibition by the urethane group occurs, so it is preferable to use only a small amount.

Specific examples of (meth) acrylate used in the present invention include, for example, glycerin monomethacrylate (trade name “Blemmer GLM” manufactured by NOF Corporation), acryloyloxyethyl phthalate (trade name “HOA-MPE” manufactured by Kyoeisha Chemical Co., Ltd.). )), Benzyl (meth) acrylate (trade name “Biscoat # 160” manufactured by Osaka Organic Chemical Co., Ltd.), nonylphenoxy polyethylene glycol acrylate (trade names “Aronix M111”, “Aronix M113”, “Aronix M117” manufactured by Toagosei Co., Ltd.) ], ECH-modified phenoxy acrylate (trade name “Aronix M5700” manufactured by Toa Gosei Co., Ltd.), EO-modified oxalic acid acrylate (trade name “HOA-MS” manufactured by Kyoeisha Chemical Co., Ltd.), EO-modified phosphate methacrylate (Kyoeisha Chemical Co., Ltd.) Product name “P-1M” ), Rosin-modified epoxy acrylate (trade name “Beamset 101” manufactured by Arakawa Chemical Co., Ltd.), etc., (meth) acrylate having one (meth) acryloyl group, bis (acryloylethyl) hydroxyethyl isocyanurate (Toagosei Co., Ltd.) Product name “Aronix M215”), EO-modified bisphenol A diacrylate (trade name “ADPE-150” manufactured by NOF Corporation), PO modified bisphenol A diacrylate (trade name “ADBP-200” manufactured by NOF Corporation) ), ECH-modified bisphenol A acrylate (trade name “DICLITE UE8200” manufactured by DIC Chemical Co., Ltd.), ECH-modified phthalic acid diacrylate (trade name “DA-721” manufactured by Nagase Chemical Co., Ltd.), ECH-modified hexahydrophthalic acid diester Acrylate (trade name, manufactured by Nagase Kasei Co., Ltd. DA-722 "), tricyclodecane dimethanol diacrylate (trade name" IRR214 "manufactured by Daicel UCB), rosin modified ester acrylate (trade name" Beamset 115B "manufactured by Arakawa Chemical Co., Ltd.), EO modified diphosphate diphosphate Methacrylate (trade name “P-2M” manufactured by Kyoeisha Chemical Co., Ltd.), tris (acryloyloxyethyl) isocyanurate (trade name “Aronix M315” manufactured by Toagosei Co., Ltd.), dimethylolpropane tetraacrylate (product manufactured by Toagosei Co., Ltd.) Name “Aronix M408”), dipentaerythritol hexaacrylate (trade name “Kayarad DPHA” manufactured by Nippon Kayaku Co., Ltd.), caprolactone-modified dipentaerythritol hexaacrylate (trade name “Kayarad DPCA-30” manufactured by Nippon Kayaku Co., Ltd.) "," Kayarad DPCA- 120 ") and the like, and (meth) acrylates having two or more (meth) acryloyl groups.

Among the above-mentioned radical polymerizable compounds, (meth) acrylate modified with lactone and (meth) acrylate modified with rosin are particularly preferable because they make the curable composition flexible and improve adhesion. Specifically, lactone-modified hydroxypivalate neopentyl glycol diacrylate (trade name “HX620” manufactured by Nippon Kayaku Co., Ltd.), lactone-modified BPA epoxy phthalate ester diacrylate (trade name “Evecryl 3708” manufactured by Daicel Cytec Co., Ltd.) ), Rosin-modified epoxy acrylate (trade name “Beamset 101” manufactured by Arakawa Chemical Co., Ltd.) and the like.

The amount of the (meth) acrylate used is not particularly limited as long as it does not impair the scope of the present invention. Specifically, it is preferably in the range of 20 to 70% by mass with respect to the total solid content of the photocurable composition for sealing of the present invention.

Examples of radical photopolymerization initiators that can be used include benzophenone, 2,2-diethoxyacetophenone, benzyl, benzoyl isopropyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, and thioxanthone. These radical photopolymerization initiators may be used alone or in combination of two or more.
A maleimide compound having photoinitiating ability can also be used. Specific examples of the maleimide compound having photoinitiating ability include maleimide compounds described in, for example, JP-A Nos. 2000-19868 and 2004-070297.

The radical photopolymerization initiator may be used alone or in combination of two or more. The mixing ratio of the radical photopolymerization initiator is not particularly limited, but it is used within the range of 0.1 to 20% by mass with respect to the total amount of the radical polymerizable compound. If it is less than 0.1% by mass, the curability of the sealing agent of the present invention may be insufficient, and if it exceeds 10% by mass, a cationic photopolymerization initiator that cannot be reacted can remain and dissolve into the liquid crystal. There is sex. Among these, 0.3 to 10% by mass is preferable.

Moreover, when using together radical photocuring type | system | group and a cationic photocuring type | system | group, the compound which has both radical-polymerizable group and the group of cationically polymerizable groups can also be used. Examples of the polymerizable compound having both radical polymerizable group and cationic polymerizable group include commercially available BPF epoxy half acrylate and BPA epoxy half acrylate (trade name “UVa1561” manufactured by Daicel Cytec Co., Ltd.) Examples thereof include compounds in which a part of the epoxy group of a compound having a plurality of epoxy groups is reacted with (meth) acrylic acid to form (meth) acryloyl.
Among these, BPA epoxy half acrylate and BPF epoxy half acrylate are more preferable because of high dilution effect with the compound represented by the general formula (1).

In the present invention, a combination of a radical photocuring system and a cationic photocuring system, specifically, a (meth) acryloyl group as a radical photocuring system and an epoxy group as a cationic photocuring system in the composition. It is still preferred that the composition coexist with the epoxy group by cationic irradiation and the (meth) acryloyl group can be radically polymerized and cured by light irradiation and firmly bonded to the substrate. In this case, in order to advance the polymerization more efficiently, a cationic photopolymerization initiator that cationically polymerizes an epoxy group in the photocurable composition, and a radical photopolymerization initiator that radically polymerizes a (meth) acryloyl group. It is preferable to use together.

(Other components Silane coupling agent)
Moreover, in order to improve adhesiveness, the well-known and usual silane coupling agent can also be mixed with the photocurable composition for liquid crystal display panel seals of this invention. Among such silane coupling agents, a silane coupling agent having a polymerizable group such as a (meth) acryloyl group or an epoxy group is copolymerized with the compound represented by the general formula (1) upon photocuring. In particular, it is particularly preferable because high adhesiveness can be obtained.

Examples of the silane coupling agent having a polymerizable group include 3- (meth) acryloyloxypropyltrimethoxysilane, 3-epoxyoxypropyltrimethoxysilane, and the like. Examples of commercially available silane coupling agents having such a polymerizable group include, for example, trade names “KBM503”, “KBE503”, “KBM502”, “KBE502”, “KBM5102”, and “KBM5103” manufactured by Shin-Etsu Chemical Co., Ltd. , “KBM403” and the like.

When the silane coupling agent is used in combination, the amount used is preferably in the range of 0.1 to 10% by mass, particularly preferably in the range of 1 to 5% by mass with respect to the total curable composition amount. If the ratio of the silane coupling agent is less than 0.1% by mass, a sufficient adhesive effect may not be obtained, and if it exceeds 10% by mass, phase separation may occur. A more preferred lower limit is 0.5 parts by mass, and a more preferred upper limit is 5 parts by mass.

(Other ingredients Other)
In the photocurable composition for sealing of the present invention, known and commonly used additives and fillers can be appropriately added depending on the purpose such as viscosity adjustment and storage stability.

For example, the filler is added for the purpose of improving the adhesiveness of the photocurable composition for sealing of the present invention by the stress dispersion effect and improving the linear expansion coefficient. For example, talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, diatomaceous earth, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, glass beads, barium sulfate, gypsum, calcium silicate Inorganic fillers such as talc, glass beads, sericite activated clay, bentonite, and organic fillers such as polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles.

The blending ratio of the filler is not particularly limited, but is preferably 1 to 100% by mass with respect to the amount of the curable composition. If it is 1% by mass or less, the effect of adding a filler is hardly obtained, and if it exceeds 100% by mass, the handling property such as the drawability of the photocurable composition for sealing of the present invention may be lowered. A more preferred lower limit is 5 parts by mass, and a more preferred upper limit is 50 parts by mass.

(viscosity)
When the viscosity of the photocurable composition for sealing a liquid crystal display panel of the present invention measured at 25 ° C. using an E-type viscometer is 100 Pa · s or more, the liquid crystal for producing a liquid crystal display element by a dropping method described later is used. More preferably, it can be used as a sealant.
If the liquid crystal display panel is less than 100 Pa · s, when the liquid crystal display panel is manufactured by the dropping method, the shape of the seal pattern formed on the transparent substrate cannot be maintained, and the sealant component is eluted in the liquid crystal, resulting in liquid crystal contamination. It may end up. A more preferred lower limit is 100 Pa · s, and a more preferred upper limit is 500 Pa · s. If it exceeds 500 Pa · s, the drawing property of the sealing agent of the present invention is not sufficient, and it may be difficult to produce a liquid crystal display panel by a dropping method. In this case, the E-type viscometer for measuring the viscosity is not particularly limited, and, for example, “DV-III” manufactured by Brookfield can be used.

(Sealant for LCD panels)
The photocurable composition for a liquid crystal display panel seal of the present invention is used as a sealant for preparing a liquid crystal display panel, and as a sealant for sealing an injection port after injecting a liquid crystal material into the liquid crystal display panel. Can be used.

The liquid crystal display panel is, for example, the photocurable composition for sealing a liquid crystal display panel according to the present invention on one of the front and back substrates provided with thin film transistors, pixel electrodes, alignment films, color filters, electrodes, and the like. After the application, the other substrate is bonded, and light is irradiated from the substrate surface side or the side surface of the substrate to cure the photocurable composition for liquid crystal display panel seals of the present invention. Next, after injecting liquid crystal into the obtained liquid crystal cell, the injection port is sealed with a sealant, whereby a liquid crystal display panel can be produced.

The liquid crystal display panel is coated with the photocurable composition for sealing a liquid crystal display panel of the present invention in a frame shape on the outer edge portion of one of the substrate surfaces. Thus, it can also be produced by a method in which the other substrate is bonded and then photocured.

In order to apply the photocurable composition for sealing a liquid crystal display panel of the present invention to the substrate surface, a dispenser may be used or a screen printing method may be used. In that case, the coating is generally applied to a line width of 0.08 to 0.1 mm and a line height of 5 to 50 μm.

The light used for curing the photocurable composition for sealing a liquid crystal display panel of the present invention is preferably ultraviolet light or visible light, and particularly preferably light having a wavelength of 300 nm to 400 nm. As the light source, for example, a high-pressure mercury lamp, a metal halide lamp, or the like can be used. When the illuminance of the light source is 500 W / m ² or more, it is preferable that curing is quick. If the light quantity to be irradiated is 20000 J / m ² or more in terms of the integrated light quantity, it can be cured well. In addition, the photocurable composition for liquid crystal display panel seals of the present invention shows good photocurability even in an air atmosphere, but when photocured in an inert gas atmosphere such as nitrogen, it cures with a small amount of accumulated light. This is more preferable.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. “Parts” in Examples and Comparative Examples indicates “parts by mass” unless otherwise specified. In addition, evaluation about adhesiveness and a voltage holding ratio was performed as follows.

<Substrate used for adhesive test>
(Glass with entire surface (SiN) x)
A non-alkali glass plate having a thickness of about 50 nm is formed by sputtering on the entire surface of a non-alkali glass plate having a thickness of 0.7 mm (product name “cornig 1737” manufactured by Corning). did.

(Plastic film with full surface ITO)
A polyether sulfone film (trade name “FS-5300” manufactured by Sumitomo Bakelite Co., Ltd.) having an ITO film formed over the entire surface was used.

(Full acrylic glass)
A non-alkali glass plate with an acrylic coating on the entire surface of an alkali-free glass plate having a thickness of 0.7 mm (product name “cornig 1737” manufactured by Corning) according to Example 1 described in Japanese Patent No. 3321858. It was.

(Plastic film with full surface (SiN) x)
A (SiN) x layer having a thickness of 50 nm was formed on the entire surface of a polycarbonate film having a thickness of 0.125 mm (trade name “Panlite” manufactured by Teijin Chemicals) according to Example 3 Example C of JP-A-2006-57121, A PC film substrate with (SiN) x was used.
It was.

(Plastic film with full surface (SiO) x)
A (SiO) x-attached PES film substrate (trade name “FST1300” from Sumitomo Bakelite) on which a SiOx layer was formed by sputtering was used.

(Full glass with ITO)
An ITO layer was formed by sputtering on the entire surface of a non-alkali glass plate having a thickness of 0.7 mm (product name “cornig 1737” manufactured by Corning) so as to have a surface resistance of 100Ω, thereby obtaining an alkali-free glass plate with ITO.

<Combination of base materials used for adhesive test>
The combinations of the substrates are as follows.
Combination A: Plastic film with whole surface ITO / Glass combination with whole surface (SiN) x B: Plastic film with whole surface ITO / Acrylic coated glass combination C: Plastic film with whole surface (SiN) x / Glass combination D with whole surface (SiN) x : Full surface (SiN) x plastic film / full surface acrylic coated glass combination E: Full surface (SiO) x plastic film / full surface (SiN) x glass combination F: Full surface (SiO) x plastic film / full surface ITO glass

<Example of combination test A>
1% by mass of spherical spacer “Haya Beads L-11S” having an average particle diameter of about 5.5 μm is added to a photocurable composition for sealing, which will be described later. A sample was obtained by stirring and defoaming with Rentaro AR250 ").
The sample was discharged from the tip of a syringe equipped with a precision nozzle having a diameter of 0.2 mm, and cut in advance to 150 mm × 15 mm using a desktop coating robot (trade name “SHOT MINI” manufactured by Musashi Engineering Co., Ltd.). On the entire surface of the plastic film with ITO, it was applied linearly over a length of 9 cm so as to be parallel to the long axis direction of the substrate. On this, “glass with whole surface (SiN) x” (size: 95 × 15 mm) was superposed so that the surface was parallel to the surface of the plastic film.

Next, after pressurizing for 2 minutes using a pressure curing device with quartz window from EHC, a high-pressure metal halide lamp was applied from the “entire glass (SiN) x-attached glass” side in the pressurized state. It was used and irradiated with UV light of 500 W / m ² for 40 seconds. The irradiation at this time was performed in an air atmosphere through a quartz window of the pressure curing apparatus with a quartz window. As a result, an evaluation sample having an adhesive width of 1 mm and an adhesive layer thickness of 5.5 μm was obtained.
The evaluation sample thus bonded was subjected to a floating roller method peeling test (90 ° peeling at a speed of 100 mm / min) described in JIS K 6854-1, and also obtained by the optimum linear method described in JIS K 6854-1. The adhesive strength (mN / mm) was determined by dividing the peel load (mN) by the adhesive width.

<Creation of liquid crystal display panel for voltage holding ratio test>
1. LCD panel production 1 (injection method)
One glass substrate “RZ-B107N1N” with ITO manufactured by EHC was sprayed with 5% ethanol dispersion of spacer “LH11S” manufactured by Hayakawa Rubber. Next, after applying the photocurable composition for sealing to another glass substrate with ITO using a dispenser, with a width of about 1 mm so that two liquid crystal injection holes are provided on the outer edge of the substrate. Two glass substrates were bonded to face each other, and under a nitrogen atmosphere, a high pressure metal halide lamp was used to irradiate the sealant part with 500 W / m ² of ultraviolet light for 40 seconds to produce a two-hole cell. Under a vacuum, a liquid crystal composition for driving a TFT (thin film transistor) (composition will be described later) is injected into a two-hole cell, and the liquid crystal composition is masked so as not to be directly exposed to ultraviolet rays, and then a photocurable composition for sealing. Two holes were sealed, and a high-pressure metal halide lamp was used to re-irradiate with 500 W / m ² of ultraviolet light for 40 seconds under a nitrogen atmosphere, thereby producing a liquid crystal display panel.

2. LCD panel production 2 (Drip method)
Two glass substrates RS-B107M1N (with a rubbed alignment film and with ITO) made by EHC were prepared, and one of them was sprayed with a 5% ethanol dispersion of a spacer “LH11S” made by Hayakawa Rubber. Next, the sealing material produced in Example 6 was applied to another glass substrate in a rectangular shape with a seal width of about 1 mm on the outer edge of the substrate using a dispenser. Next, an appropriate amount of a TFT (thin film transistor) driving liquid crystal composition (composition will be described later) is dropped inside the rectangular upper sealant on the substrate under a vacuum, and the rubbing directions of the two glass substrates are perpendicularly bonded. A cell was produced. After this cell was returned to atmospheric pressure and the distance between the substrates reached the size of the spacer, the sealant part was irradiated with UV light of 500 W / m ² for 40 seconds using a high-pressure meta-harara lamp. A liquid crystal display panel was produced.
The liquid crystal display panel was sandwiched between two orthogonal polarizing plates with the optical axis aligned, to produce a liquid crystal display element. When no voltage was applied, the display appeared transparent and bright, and when the voltage was applied, the electrode portion of the cell did not transmit light and dark display, indicating a good display state.

3. Liquid crystal composition for driving TFT (thin film transistor) used for preparing liquid crystal display panel The following three kinds of liquid crystal compositions for driving TFT (thin film transistor) used in this example were used.

液晶組成物（１）

Liquid crystal composition (1)

Physical properties of liquid crystal composition (1) Dielectric anisotropy (Δε): 5.30
Specific resistance value: 5.2 × 10 ¹⁴ Ω · m

液晶組成物（２）

Liquid crystal composition (2)

Physical properties of liquid crystal composition (2) Dielectric anisotropy (Δε): −3.1
Birefringence (Δn): 0.07
Specific resistance value: 5.6 × 10 ¹⁴ Ω · m

液晶組成物（３）

Liquid crystal composition (3)

Physical properties of liquid crystal composition (3) Dielectric anisotropy (Δε): 4.7
Birefringence (Δn): 0.29
Specific resistance value: 1.6 × 10 ¹⁴ Ω · m

<Voltage retention test>
The liquid crystal display panel produced by any of the above methods was subjected to a 60 ° C. and 90% RH wet heat exposure test, and the voltage holding ratio after 120 hours was measured. The voltage holding ratio was calculated by applying an initial voltage of 5V AC to the liquid crystal display panel at 24 ° C. for 64 microseconds and multiplying the voltage ratio before and after the frame time of 167 milliseconds by 100.

[Example 1] (HLB = 12)
Diepoxy compound having bisphenol A skeleton (trade name “EPICRON 850CRP” manufactured by DIC Chemical Industries, Ltd.) 25 parts, epoxy compound having bisphenol A skeleton (trade name “EPICRON 1050” manufactured by DIC Chemical Industries, Ltd., 10 parts, bisphenol A Epoxy ester acrylate obtained by sequentially reacting γ-caprolactone and ethyl hydroxyethyl acrylate with a reaction intermediate obtained by reacting an epoxy having a skeleton with phthalic anhydride (trade name “Evecryl 3708 manufactured by Daicel Cytec Co., Ltd.”) ”) 20 parts, 10 parts of bisphenol A type epoxy half acrylate (trade name“ UVa1561 ”manufactured by Daicel Cytec Co., Ltd.) was dissolved at 140 ° C. Then, while stirring at 120 ° C., the caprolactone-modified hydroxypivalate was dissolved. 25 parts of neopentyl glycol diacrylate (trade name “KAYARAD HX620” manufactured by Nippon Kayaku Co., Ltd.) and 10 parts of rosin-modified epoxy acrylate (trade name “Beamset 101” manufactured by Arakawa Chemical Co., Ltd.) The mixture was brought to room temperature, and 1 part of a nonionic surfactant, ethylene oxide and propylene oxide modified polydimethylsiloxane compound (hereinafter referred to as Compound A) (trade name “KF6011” manufactured by Shin-Etsu Chemical Co., Ltd., HLB = 12). In addition, it was well stirred.
Sulfonium salt photocation initiator (trade name “SP150” manufactured by Asahi Denka Co., Ltd.) 2.5 parts, silane coupling agent (trade name “KBM5103”, Shin-Etsu Chemical Co., Ltd.) 5.0 parts, and radical light 2,2-Dimethoxy-2-phenylacetophenone (trade name “IRGACURE 651” of Ciba Specialty Chemicals), which is a polymerization initiator, was added and stirred while being heated and dissolved as necessary. 5 parts of the trade name “RY-200S” was added and kneaded with three rolls to obtain a photocurable composition A for liquid crystal display panel seals.
About the photocurable composition A for liquid crystal display panel seals, while producing a liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 2] (HLB = 14)
Instead of 1 part of the compound (A) in Example 1, 1 part of a polydimethylsiloxane compound (B) modified with polyethylene oxide (trade name “TSF-4440” manufactured by Toray Dow Corning, HLB = 14) A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that it was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 3] (HLB = 10)
Instead of 1 part of compound (A) in Example 1, polydimethylsiloxane compound (C) modified with polyethylene oxide (trade name “KF-353” manufactured by Shin-Etsu Chemical Co., Ltd., HLB = 10, 430 mPas) 1 A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that the parts were used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

Example 4 (HLB = 13)
Instead of 1 part of compound (A) in Example 1, polydimethylsiloxane compound (D) modified with polyethylene oxide, polypropylene oxide, and glycidyl ether group (trade name “X22-4741” manufactured by Shin-Etsu Chemical Co., Ltd.) A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that 0.75 part of HLB = 13) was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 5] (HLB = 13, 0.3 part)
Instead of 1 part of compound (A) in Example 1, polydimethylsiloxane compound (D) modified with polyethylene oxide, polypropylene oxide, and glycidyl ether group (trade name “X22-4741” manufactured by Shin-Etsu Chemical Co., Ltd.) A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that 0.3 part of HLB = 13) was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 6] (HLB = 13, 1.5 parts)
Instead of 1 part of compound (A) in Example 1, polydimethylsiloxane compound (D) modified with polyethylene oxide, polypropylene oxide, glycidyl ether group (trade name “X22-4741” manufactured by Shin-Etsu Chemical Co., Ltd., HLB) = 13) A photocurable composition for a liquid crystal display panel seal was obtained according to the same method as described in Example 1 except that 0.3 part was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 7] (using oxetane)
In Example 4, an epoxy compound having a bisphenol A skeleton (trade name “EPICRON 1050” manufactured by DIC was replaced with 10 parts, and 10 parts of a biphenol type oxetane compound (trade name “OXBP” manufactured by Ube Industries, Ltd.) was used. Except for the above, a photocurable composition for sealing a liquid crystal display panel was obtained according to the same method as described in Example 1. About the composition, a liquid crystal display panel was prepared by the method of liquid crystal display panel preparation 1, Evaluation was performed according to the evaluation method, and the results are shown in Table 1.

[Example 8] (HLB = 13, comparison with cited document 7)
Instead of 1 part of compound (A) in Example 1, polydimethylsiloxane compound (D) modified with polyethylene oxide, polypropylene oxide, and glycidyl ether group (trade name “X22-4741” manufactured by Shin-Etsu Chemical Co., Ltd.) HLB = 13) 1.0 parts, and an epoxy compound having a bisphenol A skeleton (trade name “EPICRON 1050” manufactured by DIC Corporation, 10 parts, a compound represented by the following general formula described in Reference 7 (EP ) Except for using 10 parts, a photocurable composition for a liquid crystal display panel seal was obtained in accordance with the same method as described in Example 1. The composition was prepared by the method of liquid crystal display panel preparation 1 above. A liquid crystal display panel was produced and evaluated according to the evaluation method, and the results are shown in Table 1.

（ＥＰ）

(EP)

Example 9 (HLB = 13.6, 1.0 part)
Example 1 except that 1.0 part of a polyoxyethylene lauryl ether compound (trade name “Emulgen 109P”, HLB = 13, manufactured by Kao Corporation) was used instead of 1 part of compound (A) in Example 1. According to the same method as described in 1, a photocurable composition for a liquid crystal display panel seal was obtained. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 10] (HLB = 15.5, 1.0 part)
Instead of 1 part of compound (A) in Example 1, 1.0 part of decaglyceryl monolaurate compound (trade name “DECAGLYN-1-L”, HLB = 15.5, manufactured by Nikko Chemicals Co., Ltd.) is used. A photocurable composition for a liquid crystal display panel seal was obtained according to the same method as described in Example 1 except that. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 11] (HLB = 15.0, 1.0 part)
Instead of 1 part of the compound (A) in Example 1, 1.0 part of a polyoxyethylene sorbitan monooleate compound (trade name “TO-10V” manufactured by Nikko Chemicals Co., Ltd., HLB = 15.0) A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that it was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Example 12] (HLB = 16.3, 1.0 part)
Instead of 1 part of compound (A) in Example 1, 1- (allyloxy) -2,3-epoxypropane was modified with alcohol having 11 to 14 carbon atoms and ethylene oxide (ER) represented by the following general formula (Same as described in Example 1 except that 1.0 part of ADEKA Co., Ltd., trade name “ER-30”, HLB = 16.3, 65% aqueous solution) dehydrated by freeze drying was used. According to the method, a photocurable composition for a liquid crystal display panel seal was obtained. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

（ＥＲ）

(ER)

In the above general formula, R is an alkyl group having 10 to 14 carbon atoms, n represents an integer of repeating units, and n = 30.

[Comparative Example 1] (without additive)
A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that 1 part of Compound (A) in Example 1 was not added. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 2] (HLB = 5)
Instead of 1 part of compound (A) in Example 1, other than polydimethylsiloxane compound (E) modified with polyethylene oxide or polypropylene oxide (trade name “KF-6015”, HLB = 5, manufactured by Shin-Etsu Chemical Co., Ltd.) Obtained a photocurable composition for sealing a liquid crystal display panel according to the same method as described in Example 1. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 3] (HLB = 7)
Instead of 1 part of compound (A) in Example 1, other than polydimethylsiloxane compound (E) modified with polyethylene oxide or polypropylene oxide (trade name “KF-6012” manufactured by Shin-Etsu Chemical Co., Ltd., HLB = 7) Obtained a photocurable composition for sealing a liquid crystal display panel according to the same method as described in Example 1. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 4] (HLB = 12, 5 parts added)
A photocurable composition for sealing a liquid crystal display panel was obtained in the same manner as described in Example 1 except that 1 part of the compound (A) in Example 1 was changed to 5 parts. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 5] (No additive, comparison with Cited Document 7)
Example 9 except that polydimethylsiloxane compound (D) modified with polyethylene oxide, polypropylene oxide, glycidyl ether group (trade name “X22-4741” manufactured by Shin-Etsu Chemical Co., Ltd., HLB = 13) in Example 9 is not added. A photocurable composition for liquid crystal display panel seals was obtained according to the same method as described in 7. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 6] (HLB = 9.6, 1.0 part)
Instead of 1 part of compound (A) in Example 1, 1.0 part of polyoxyethylene sorbitan monostearic acid ester compound (trade name “TS-106” manufactured by Nikko Chemicals, HLB = 9.6) A photocurable composition for sealing was obtained in the same manner as described in Example 1 except that was used. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

[Comparative Example 7] (Fluorosurfactant 1.0 part)
Example 1 except that 1.0 part of a perfluoroalkylethylene oxide compound (trade name “Megafac F-444” manufactured by DIC Corporation) was used instead of 1 part of compound (A) in Example 1. According to the same method as described in 1, a photocurable composition for sealing was obtained. About this composition, while producing the liquid crystal display panel by the method of the said liquid crystal display panel preparation 1, it evaluated according to the said evaluation method, The result was shown in Table 1.

In Table 1, “X” indicates “easy peeling and measurement is not possible”.

As a result, the liquid crystal display panels using the photocurable compositions for sealing obtained in Examples 1 to 12 exhibited a voltage holding ratio of 90% or more and good adhesive strength.
Comparative Examples 1 and 5 are examples in which a nonionic surfactant is not added. Comparative Examples 2, 3, and 6 are examples in which a nonionic surfactant having an HLB of less than 10 is added, and Comparative Example 7 is an example in which a fluorosurfactant is added. All were inferior in adhesiveness. Further, Comparative Example 4 is an example in which the addition amount exceeds 4% by mass, but the voltage holding ratio has decreased.

Claims (5)

A photocurable composition for sealing a liquid crystal display panel, comprising 0.1 to 4% by mass of a nonionic surfactant having an HLB value of 10 or more based on the total solid content of the photocurable composition. The photocurable composition for a liquid crystal display panel seal according to claim 1, wherein the nonionic surfactant is an alkylene oxide-modified polydimethylsiloxane. The photocurable composition for liquid crystal display panel seals according to claim 1, comprising a cationically polymerizable compound and a photocationic polymerization initiator. The photocurable composition for a liquid crystal display panel seal according to claim 3, comprising a radical polymerizable compound. A liquid crystal display panel comprising the photocurable composition for sealing a liquid crystal display panel according to any one of claims 1 to 4.