KR20170012038A - Liquid crystal sealing agent, and liquid crystal display cell using the same - Google Patents

Abstract

The present invention relates to a liquid crystal sealing agent for a liquid crystal dropping process, which is cured by heat. The liquid crystal sealing agent shows significantly low corrosion of wiring after a moisture resistance test and low liquid crystal contamination and has excellent adhesion strength, and thus provides a liquid crystal display with high precision, a high response rate, a low driving voltage and long service life. The liquid crystal sealing agent for a liquid crystal dropping process comprises a curable compound, wherein the cured product obtained merely by carrying out heat curing at 130 deg. C for 1 hour without UV irradiation shows an absorption ratio of 2.0% or less as determined according to JIS-K7209 and has moisture permeability of 130g/m^2*24h or less as determined according to JIS-K7129.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display (LCD)

The present invention relates to a liquid crystal sealant which is cured by heat and which is used in a liquid crystal dropping method. More particularly, the present invention relates to a liquid crystal sealing agent for a liquid crystal dropping method which is extremely low in wiring corrosion resistance after a humidity resistance test, and is also excellent in general characteristics such as low-liquid crystal stain resistance and adhesive strength.

Background Art [0002] As a liquid crystal display cell of recent years has become larger in size, a so-called liquid crystal dropping method has been proposed (see Patent Document 1 and Patent Document 2). Specifically, the liquid crystal is sealed by dropping liquid crystal on the inner side of a weir of a liquid crystal seal formed on one substrate, and then bonding the other substrate to each other.

However, in the liquid crystal dropping method, since the liquid crystal sealant in an uncured state is in contact with the liquid crystal, the liquid crystal sealant component dissolves (dissolves) in the liquid crystal at that time, thereby lowering the resistance value of the liquid crystal and causing display defects in the vicinity of the seal .

In order to solve this problem, a liquid crystal sealing agent for a liquid crystal dropping method is currently used in combination with a photothermal (photo heat) type and is put to practical use (Patent Documents 3 and 4). In the liquid crystal dropping method using the liquid crystal sealing agent, the liquid crystal sealing agent sandwiched between the substrates is first irradiated with light, and then primary cured, followed by heating to secondary cure. According to this method, the uncured liquid crystal sealant can be quickly cured by light, and it is possible to suppress the dissolution (dissolution) of the liquid crystal sealant component into the liquid crystal. Furthermore, although the problem of insufficient adhesive strength due to curing shrinkage or the like at the time of photo-curing occurs only by photo-curing, a stress relaxation effect can be obtained by secondary curing by heat treatment in combination with heat treatment for heat radiation type, .

With this photo-heat curable type liquid crystal sealant for a liquid crystal dropping method, a liquid crystal dropping method has become a generally used method.

With the practical use of the liquid crystal dropping method, even a large-sized liquid crystal display cell can be easily manufactured, resulting in the spread of a liquid crystal display.

On the other hand, the liquid crystal dropping method may have a defect in the quality of the manufactured liquid crystal display cell. One of them is a problem of causing defects in the driving of the liquid crystal after the moisture proof reliability. This problem is a problem that has arisen also in the liquid crystal display cell manufactured by the conventional liquid crystal injection method, but is particularly remarkable in the liquid crystal display cell manufactured by the liquid crystal drop method. In order to solve this problem, various devises have conventionally been made. For example, it is possible to improve the reaction rate by adding a thermal radical polymerization initiator or a curing accelerator, or to use a material having low solubility in liquid crystals as a constituent.

However, these studies have not yet reached the realization of a liquid crystal sealing agent for a liquid crystal dropping method which sufficiently solves the above problems.

Japanese Patent Application Laid-Open No. 63-179323 Japanese Patent Application Laid-Open No. 10-239694 Japanese Patent No. 3583326 Japanese Patent Application Laid-Open No. 2004-61925 Japanese Patent Application Laid-Open No. 2004-126211 Japanese Patent Application Laid-Open No. 2009-8754 International Publication No. 2008/004455

The present invention relates to a liquid crystal sealing agent for a liquid crystal dropping method which is cured by heat and which is extremely low in wiring corrosion resistance after humidity resistance test and excellent in general characteristics such as low liquid crystal stain resistance and adhesive strength, Liquid crystal sealing agent for a liquid crystal dropping method which realizes high-definition, high-speed response, low-voltage driving, and long life.

The present inventors have made intensive investigations in order to solve the problems of the above driving defects. As a result, it has been found that the wiring corrosion is caused by wiring corrosion after the humidity resistance test. The wiring corrosion is insufficient for curing in the ultraviolet ray, And that the moisture permeability and absorbency of the portions are influential, leading to the present invention.

That is, the present invention relates to the following 1) to 14). In the present specification, the term "(meth) acryl" means "acrylic" and / or "methacryl". Further, the liquid crystal sealant for liquid crystal dropping process may be simply referred to as " liquid crystal sealant ".

One)

(A) a curable compound,

Without irradiation with ultraviolet rays and at 130 ℃ below the measured absorption rate in accordance with a first time series only did the cured product, JIS-K7209 curing of 2.0%, a liquid crystal dropping a water vapor transmission rate of not more than 130g / m ² * 24h measured according to JIS-K7129 Liquid crystal sealant for construction method.

2)

The liquid crystal sealing agent for liquid crystal dripping method according to (1) above, further comprising (B) a thermal radical polymerization initiator.

3)

The thermosetting composition as described in 1) or 2) above, wherein the thermal radical polymerization initiator (B) is a thermal radical polymerization initiator containing no oxygen-oxygen bond (-OO-) and nitrogen- Liquid crystal sealing agent for liquid crystal dropping method.

4)

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of (1) to (3) above further containing (C) a photo radical polymerization initiator.

5)

The liquid crystal sealing agent according to any one of (1) to (4) above, further comprising (D) a filler and a content of the filler in the total amount of the liquid crystal sealant of 20 mass% or more.

6)

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of (1) to (5) above, wherein the component (D) is a mixture of (D-1) an organic filler and (D-2) an inorganic filler.

7)

The liquid crystal sealing agent according to any one of (1) to (6) above, wherein the content of the inorganic filler in the total amount of the liquid crystal sealing agent of the component (D-2) is 20 mass% or more.

8)

The liquid crystal sealing agent for liquid crystal dropping method according to any one of (1) to (7) above, wherein the component (A) curable compound is an epoxy (meth) acrylate compound.

9)

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of 1) to 7) above, wherein the component (A) curable compound is a mixture of an epoxy (meth) acrylate compound and an epoxy compound.

10)

The liquid crystal sealing agent for a liquid crystal dripping method according to any one of (1) to (9) above further containing (E) a thermosetting agent.

11)

10. The liquid crystal sealing agent for liquid crystal dropping method according to 10), wherein the component (E) thermosetting agent is an organic acid hydrazide.

12)

The liquid crystal sealing agent for liquid crystal dropping method according to any one of (1) to (11) above further comprising (F) a silane coupling agent.

13)

A liquid crystal display cell comprising two substrates, in which a liquid crystal is dropped on the inner side of a weir of a liquid crystal sealing agent for a liquid crystal dropping method according to any one of [1] to [12] And then curing the other substrate by light and / or heat. The method of manufacturing a liquid crystal display cell according to claim 1,

14)

A liquid crystal display cell sealed with a cured product obtained by curing the liquid crystal sealant for a liquid crystal dropping method according to any one of 1) to 12) above.

The liquid crystal sealing agent for a liquid crystal dropping method of the present invention is extremely useful as a liquid crystal sealing agent for a liquid crystal display element because wiring corrosion can be suppressed to the utmost, and also the stain of low liquid crystal stains and adhesion strength are excellent.

Fig. 1 is a view showing a curing width of a light-shielding portion. A liquid crystal sealant containing 1 wt% of glass fiber of 5 mu m in thickness was applied to the center of the glass substrate on which the chromium plating was etched, and the resultant was bonded using a black matrix substrate as a counter substrate and fixed with a clip (before ultraviolet irradiation). After irradiating ultraviolet rays of 3000 mJ / cm ² from the side of the glass substrate on which chromium was etched, the two bonded substrates were peeled off, and a portion shielded from light under the chromium was observed with a microscope to measure the curing width of the light shielding portion .

The liquid crystal sealing agent of the present invention contains (A) a curable compound.

The component (A) is not particularly limited as long as it undergoes polymerization reaction by light or heat, and examples thereof include a curable compound having a (meth) acryloyl group and a curable compound having an epoxy group.

Examples of the curable compound having a (meth) acryloyl group include (meth) acrylic ester and epoxy (meth) acrylate. As the (meth) acrylic ester, benzyl methacrylate, cyclohexyl methacrylate, glycerol dimethacrylate, glycerol triacrylate, EO-modified glycerol triacrylate, pentaerythritol acrylate, trimethylol propane triacrylate , Tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate, fluoroglycinol triacrylate, and the like. The epoxy (meth) acrylate can be obtained by a known method by the reaction of an epoxy compound with (meth) acrylic acid. The epoxy compound to be used as the raw material is not particularly limited, but a bifunctional or more epoxy compound is preferable. Examples thereof include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolak type epoxy compound, Cresol novolak type epoxy compounds, bisphenol A novolak type epoxy compounds, bisphenol F novolak type epoxy compounds, alicyclic epoxy compounds, aliphatic chain epoxy compounds, glycidyl ester type epoxy compounds, glycidylamine type epoxy compounds, Dicyclopentadiene epoxy compounds, phenol novolac epoxy compounds having a triphenol methane skeleton, diglycidyl ether compounds of bifunctional phenols such as catechol and resorcinol, 2 Diglycidyl ethers of functional alcohols, and their halides, hydrogenated And the like. Of these, epoxy compounds having a resorcin skeleton are preferable from the viewpoint of liquid crystal staining, and for example, resorcin diglycidyl ether and the like. The ratio of the epoxy group to the (meth) acryloyl group is not limited, and is appropriately selected from the viewpoints of process suitability and liquid crystal stain resistance.

Therefore, the preferred curable compound having a (meth) acryloyl group is a curable compound having a (meth) acryloyl group and further having a resorcin skeleton, and examples thereof include acrylic esters of resorcin diglycidyl ether Methacrylic acid ester of resorcin diglycidyl ether.

As the curing compound having an epoxy group, an epoxy compound can be mentioned. The epoxy compound is not particularly limited but is preferably a bifunctional or more epoxy compound. Examples thereof include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolak type epoxy compounds, Type epoxy compounds, bisphenol A novolak type epoxy compounds, bisphenol F novolak type epoxy compounds, alicyclic epoxy compounds, aliphatic chain epoxy compounds, glycidyl ester type epoxy compounds, glycidylamine type epoxy compounds, A phenol novolak type epoxy compound having a triphenol methane skeleton, a diglycidyl ether compound of a bifunctional phenol, a diglycidyl ether compound of a bifunctional alcohol, And their halides, hydrogenated products, and the like. Of these, preferred are bisphenol-type epoxy compounds and novolak-type epoxy compounds from the standpoint of liquid crystal staining.

The curable compound having a (meth) acryloyl group and the curable compound having an epoxy group can be used in combination of two or more kinds, and a particularly preferable embodiment of the present invention is to use a mixture of a (meth) acrylated epoxy compound and an epoxy compound .

The content of the component (A) in the liquid crystal sealing agent of the present invention is usually 30 to 75 mass%, preferably 40 to 65 mass%. When the epoxy compound and the (meth) acrylated epoxy compound are used in combination, the content of the epoxy compound in the component (A) is usually 3 to 30% by mass, preferably 5 to 20% by mass, 8 to 15% by mass.

The liquid crystal sealing agent of the present invention has an absorptivity of not more than 2.0% measured according to JIS-K7209 (Method D) of a cured product which is thermally cured only at 130 DEG C for one hour without irradiation of ultraviolet rays 60 < 0 > C and 90% environment is used). The reason is that the moisture absorbed in the liquid crystal sealant accelerates the decomposition of organic substances in the liquid crystal sealant and further transports decomposition products and impurity ions out of the liquid crystal sealant.

The water absorption rate is preferably 1.8% or less, more preferably 1.6% or less.

The liquid crystal sealing agent of the present invention has a moisture permeability of 130 g / m ² * 24 h or less as measured by a method according to JIS-K7129 (Method A) of a cured product obtained by thermally curing only at 130 ° C for one hour without irradiating ultraviolet rays . This is because the moisture permeating through the liquid crystal sealing agent has a large influence on the wiring corrosion. On the other hand, the measurement according to JIS-K7129 (method A) can be performed using Lyssy L80-5000 manufactured by Systechillinois. The set test temperature is set at 60 캜.

The moisture permeability is preferably, 110g / m ² * 24h or less, and more preferably from 90g / m ² * 24h or less.

The liquid crystal sealing agent of the present invention can improve the curing rate and the degree of curing using (B) a thermal radical polymerization initiator.

The thermal radical polymerization initiator is not particularly limited as long as it is a compound that generates radicals by heating to initiate a chain polymerization reaction. However, the thermal radical polymerization initiator may be an organic peroxide, an azo compound, a benzoin compound, a benzoin ether compound, an acetophenone compound, , And benzopinacol is suitably used. Examples of organic peroxides include Kayamek ^RTM A, M, R, L, LH, SP-30C, Percadox CH-50L, BC-FF, Cadox B- 40ES, Percadox 14, Trigonox ^RTM 22- 70E, 23-C70, 121, 121-50E, 121-LS50E, 21-LS50E, 42, 42LS, Kaya ester ^{RTM P-70, TMPO-70} , CND-C70, OO-50E, AN, kaya butyl ^RTM B, peoka DOX 16, kaya carbon ^{RTM BIC-75, AIC-75} ( go exigua Kujo Co., Ltd.), buffer Mech ^RTM N, H, S, F, D, G, buffer hexahydro ^RTM H, HC, wave TMH, C, V , 22, MC, PERCURE ^RTM AH, AL, HB, PERBUTYL ^RTM H, C, ND, L, PERCYMIL ^RTM H, D PERROYL ^RTM IB, IPP, PEROTA ^RTM ND Is available as a commercial product.

As the azo compound, VA-044, V-070, VPE-0201, VSP-1001 (manufactured by Wako Pure Chemical Industries, Ltd.) and the like are commercially available. In the present specification, superscript RTM means registered trademark.

Preferred as the component (B) is a thermal radical polymerization initiator having no oxygen-oxygen bond (-O-O-) or nitrogen-nitrogen bond (-N = N-) in the molecule. A thermal radical polymerization initiator having an oxygen-oxygen bond (-OO-) or a nitrogen-nitrogen bond (-N = N-) in a molecule generates a large amount of oxygen or nitrogen during generation of radicals, There is a fear that the properties such as the bonding strength may be lowered. A thermal radical polymerization initiator of the benzopinacol system (including chemically modified benzopinacol) is particularly suitable. Specific examples thereof include benzopinacol, 1,2-dimethoxy-1,1,2,2-tetraphenylethane, 1,2-diethoxy-1,1,2,2-tetraphenylethane, 2-diphenoxy-1,1,2,2-tetraphenylethane, 1,2-dimethoxy-1,1,2,2-tetra (4-methylphenyl) 1,1,2,2-tetra (4-methoxyphenyl) ethane, 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane, 1,2- Siloxy) -1,1,2,2-tetraphenylethane, 1,2-bis (t-butyldimethylsiloxy) -1,1,2,2-tetraphenylethane, 1-hydroxy- Trimethylsiloxy-1,1,2,2-tetraphenylethane, 1 -hydroxy-2-triethylsiloxy-1,1,2,2-tetraphenylethane, 1 -hydroxy- Butyldimethylsiloxy-1,1,2,2-tetraphenylethane, and the like, preferably 1-hydroxy-2-trimethylsiloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-triethylsiloxy-1,1,2,2-tetraphenylethane, 1 -hydro 2-tert-butyldimethylsiloxy-1,1,2,2-tetraphenylethane, 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane, Preferably 1-hydroxy-2-trimethylsiloxy-1,1,2,2-tetraphenylethane, 1,2-bis (trimethylsiloxy) -1,1,2,2- And particularly preferably 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane.

Benzopinacol is commercially available from Tokyo Chemical Industry Co., Ltd., Wako Junya Kogyo Co., Further, etherification of the hydroxy group of benzopinacol can be easily synthesized by a known method. In addition, the hydroxy group of benzopinacol can be obtained by synthesizing by silylating a corresponding benzopinacol and various silylating agents in the presence of a basic catalyst such as pyridine. Examples of silylating agents include trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) Triethylchlorosilane (TECS) as a triethylsilylating agent, t-butylmethylsilane (TBMS) as a tert-butyldimethylsilylating agent, and the like. These reagents are readily available in the market of silicon derivative makers and the like. The reaction amount of the silylating agent is preferably 1.0 to 5.0 times as much as the molar amount of the hydroxyl group of the target compound. More preferably 1.5 to 3.0 moles per mole. If the molar ratio is less than 1.0 mol, the reaction efficiency is poor and the reaction time is prolonged, thereby promoting pyrolysis. If it is more than 5.0 times the molar amount, the separation may be deteriorated at the time of recovery, or the purification may become difficult.

It is preferable that the component (B) is made to be uniformly dispersed by reducing the particle diameter. If the average particle diameter is too large, the glass substrate becomes a defective factor, for example, the gap is not formed well when the upper and lower glass substrates are bonded during the manufacture of the liquid crystal display cell with a narrow gap. Therefore, the average particle diameter is preferably 5 μm or less, more preferably 3 μm or less to be. Further, although it may be thinned without limitation, the lower limit is usually about 0.1 mu m. The particle size can be measured by a laser diffraction / scattering type particle size distribution analyzer (dry type) (LMS-30 manufactured by Seishin Enterprise Co., Ltd.).

The content of the component (B) is preferably 0.0001 to 10 mass%, more preferably 0.0005 to 5 mass%, and particularly preferably 0.001 to 3 mass%, based on the total amount of the liquid crystal sealing agent.

The liquid crystal sealing agent of the present invention can be used as a liquid crystal sealing agent for a photothermal junction type by using (C) a photo radical polymerization initiator.

The photo radical polymerization initiator is not particularly limited as long as it is a compound which generates a radical by irradiation of ultraviolet rays or visible light to initiate a chain polymerization reaction. Examples thereof include benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, Methyl thiophenone, ethyl thioxanthone, benzophenone, 2-ethyl anthraquinone, 2-hydroxy-2-methylpropiophenone, 2- methyl- [4- (methylthio) Triphenylphosphine oxide, triphenylphosphine oxide, diphenylphosphine oxide, diphenylphosphine oxide, diphenylphosphine oxide, diphenylphosphine oxide, ^{Specifically, IRGACURE RTM 651, 184, 2959} , 127, 907, 369, 379 EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE RTM 1173, LUCIRIN RTM TPO ( all of BASF Co.), Sheikh come ^RTM Z , BZ, BEE, BIP, and BBI (all manufactured by Seiko Chemical Co., Ltd.).

From the viewpoint of liquid crystal contamination, it is preferable to use one having a (meth) acryl group in the molecule. For example, a combination of 2-methacryloyloxyethyl isocyanate and 1- [4- (2- Methoxy-phenyl) -2-hydroxy-2-methyl-1-propan-1-one are suitably employed. This compound can be prepared by the method described in WO 2006/027982.

From the viewpoint of enhancing the curability of the light-shielding portion not sufficiently exposed to light by the wiring or the black matrix, it is preferable that the extinction coefficient at 350 nm measured in acetonitrile is 500 ml · g ^-1 · cm or more. For example, IRGACURE ^RTM 651, 907, 369, 379EG, 819, 784, OXE01, OXE02, LUCIRIN ^RTM TPO (all from BASF), diethyl thioxanthone, benzophenone and the like.

Component (C) that can be used as the liquid crystal sealant of the present invention The content of the photo-radical polymerization initiator in the liquid crystal sealant is usually 0.1 to 20% by mass, preferably 0.2 to 15% by mass, to be.

The liquid crystal sealing agent of the present invention can improve the adhesive strength by using the (D) filler. The filler may be an organic filler (D-1), an inorganic filler (D-2) or a mixture thereof, but it is preferably a mixture of both because they have different functions.

The content of the filler (D) in the total amount of the liquid crystal sealant is usually from 5 to 70 mass%, preferably from 10 to 60 mass%. Furthermore, when the content of the filler (D) is 20 mass% or more, the effect of the present invention is particularly remarkable, and particularly preferably 20 to 50 mass%.

Component (D-1) Examples of the organic filler include urethane fine particles, acrylic fine particles, styrene fine particles, styrene-olefin fine particles and silicon fine particles. As the silicone fine particles, KMP-594, KMP-597, KMP-598 (manufactured by Shin-Etsu Chemical Co., Ltd.), Torayfil ^RTM E-5500, 9701 and EP- (Manufactured by Mitsubishi Chemical) are preferable as the styrene fine particles, and Lavalon ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C and SJ6300C ^RTM SEPS2004 and SEPS2063 are preferred.

These organic fillers may be used alone or in combination of two or more kinds. Further, two or more types may be used to form a core shell structure. Of these, preferred are acrylic fine particles and silicon fine particles.

When the acrylic fine particles are used, acrylic rubber having a core shell structure composed of two types of acrylic rubber is preferable, and it is particularly preferable that the core layer is n-butyl acrylate and the shell layer is methyl methacrylate . It is sold by Aika Kogyo Co., Ltd. as Zeffiak ^RTM F-351.

Examples of the silicon fine particles include crosslinked organopolysiloxane powder and crosslinked dimethylpolysiloxane powder having a straight chain. As the composite silicone rubber, those obtained by coating a silicone compound (for example, polyorganosiloxane compound) with the surface of the silicone rubber may be mentioned. Particularly preferred among these fine particles are composite silicone rubber microparticles of a silicone rubber of a straight-chain dimethylpolysiloxane crosslinked powder or a silicone compound-coated straight-chain dimethylpolysiloxane crosslinked powder. These may be used alone, or two or more of them may be used in combination. Preferably, the shape of the rubber powder is a spherical shape having a small viscosity increase after the addition. When the component (D) is used in the liquid crystal sealing agent of the present invention, it is usually 5 to 50 mass%, preferably 5 to 40 mass%, of the total amount of the liquid crystal sealing agent.

Component (D-2) As the inorganic filler, inorganic fillers such as silica, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, Examples of the inorganic filler include magnesium, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide disulfide and asbestos. Alumina, talc, and the like, although it is preferably boron, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate and aluminum silicate. These inorganic fillers may be used by mixing two or more kinds.

If the average particle diameter of the inorganic filler is too large, it becomes a cause of defects such that the gap formation at the time of bonding of the upper and lower glass substrates during the production of the liquid crystal cell with a narrow gap is not performed well. Therefore, the average particle diameter is preferably 2000 nm or less, More preferably 300 nm or less. The lower limit is preferably about 10 nm, and more preferably about 100 nm. The particle size can be measured by a laser diffraction / scattering type particle size distribution analyzer (dry type) (LMS-30, Seishin Enterprise Co., Ltd.).

In the case of using the inorganic filler in the liquid crystal sealing agent of the present invention, the amount of the liquid crystal sealing agent is preferably about 10 to 50 mass%, but when the amount is 20 mass% or more, the effect of the present invention becomes more remarkable. Particularly preferably 20 to 50% by mass.

The liquid crystal sealing agent of the present invention may contain (E) a thermosetting agent.

The heat curing agent means a heat curing agent which does not generate radicals by heating, unlike the thermal radical polymerization initiator (B). Specifically, there are exemplified polyvalent amines, polyhydric phenols, and organic acid hydrazide compounds reacting nucleophilic (non-covalent) by an unshared electron pair or an anion in a molecule. However, the present invention is not limited thereto. Of these, organic acid hydrazide compounds are particularly suitably used. For example, the aromatic hydrazide terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridine dihydrazide, 1,2,4-benzene Trihydrazide, 1,4,5,8-naphthoic acid tetra hydrazide, pyromellitic acid tetra hydrazide, and the like. In addition, the aliphatic hydrazide compound can be, for example, form hydrazide, acetohydrazide, propionic acid hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutar But are not limited to, acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, sebacic acid dihydrazide, 1,4-cyclohexane dihydrazide, tartaric acid dihydrazide, N, N'-hexamethylene bis-semicarbazide, citric acid trihydrazide, nitriloacetic acid trihydrazide, cyclohexyl stearic acid trihydrazide, 1,3 < RTI ID = 0.0 > (Hydrazinocarbonylethyl) -5-isopropyl hydantoin, and the like (1-hydrazinocarbonylmethyl) isocyanurate having a valine hydantoin skeleton (a skeleton in which the carbon atom of the hydantoin ring is replaced with an isopropyl group), tris (1-hydrazinocarbonylmethyl) (3-hydrazinocarbonylethyl) isocyanurate, tris (1-hydrazinocarbonylethyl) isocyanurate, tris (3-hydrazinocarbonylpropyl) isocyanurate, bis Carbonyl ethyl) isocyanurate, and the like. In view of the balance between the curing reactivity and the potential, it is preferable to use isophthalic acid dihydrazide, malonic acid dihydrazide, adipic acid dihydrazide, tris (1-hydrazinocarbonylmethyl) isocyanurate, tris (3-hydrazinocarbonylethyl) isocyanurate, tris (2-hydrazinocarbonylethyl) isocyanurate, and tris (3-hydrazinocarbonylpropyl) Is tris (2-hydrazinocarbonylethyl) isocyanurate.

Component (E) may be used alone or in combination of two or more. When the component (E) is used in the liquid crystal sealing agent of the present invention, it is usually 0.1 to 10 mass%, preferably 1 to 5 mass%, of the total amount of the liquid crystal sealing agent.

The liquid crystal sealing agent of the present invention can be improved in adhesive strength and moisture resistance by adding a silane coupling agent as the component (F).

Examples of the component (F) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4 (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) aminopropyltrimethoxysilane, N- Aminopropyl) trimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzyl Amino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, . Since these silane coupling agents are sold by Shin-Etsu Chemical Co., Ltd. as KBM series, KBE series, etc., they are readily available from the market. When the component (F) is used in the liquid crystal sealing agent of the present invention, 0.05 to 3 mass% of the total amount of the liquid crystal sealing agent is suitable.

The liquid crystal sealing agent of the present invention may further contain additives such as a curing accelerator such as organic acid and imidazole, a radical polymerization inhibitor, a pigment, a leveling agent, a defoaming agent, and a solvent, if necessary.

Examples of the curing accelerator include organic acids and imidazoles.

As the organic acid, an organic carboxylic acid or an organic phosphoric acid can be exemplified, but an organic carboxylic acid is preferable. Specific examples thereof include aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenonetetracarboxylic acid and furandicarboxylic acid; aromatic carboxylic acids such as succinic acid, adipic acid, dodecane diacid, sebacic acid, cydoadropionic acid, cyclohexane (2-carboxyethyl) isocyanurate, tris (2-carboxyethyl) isocyanurate, tris (2-carboxyethyl) isocyanurate, tris And the like.

Examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2- Benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, Ethyl-2-undecylimidazole, 2,4-diamino-6 (2'-methylimidazole (1 ')) (2 '-ethyl-4-methylimidazole (1')) ethyl-s-triazine, 2 (2'-methylimidazole (1 ')) ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 Phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-Cyanoethyl-2-phenyl-3,5-dicyano Methoxymethylimidazole, and the like.

When a curing accelerator is used in the liquid crystal sealing agent of the present invention, it is usually 0.1 to 10 mass%, preferably 1 to 5 mass%, based on the total amount of the liquid crystal sealing agent.

The radical polymerization inhibitor is not particularly limited so long as it is a compound that reacts with a radical generated from a photo radical polymerization initiator or a thermal radical polymerization initiator to prevent polymerization, and examples thereof include quinone, piperidine, . Specific examples include naphthoquinone, 2-hydroxynaphthoquinone, 2-methylnaphthoquinone, 2-methoxynaphthoquinone, 2,2,6,6-tetramethylpiperidine-1-oxyl, 2 , 2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-methoxypiperidin- 4-phenoxypiperidine-1-oxyl, hydroquinone, 2-methylhydroquinone, 2-methoxyhydroquinone, parabenzoquinone, butylated hydroxyanisole, 2,6-di-t (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene Bis (4-ethyl-6-t-butylphenol), 4,4'-thiobis-3-methyl- butylphenol) propionyloxy] ethyl], 2,4-bis [1,1-dimethyl-2- [ , 8,10-tetraoxaspiro [5,5] undecane, tetrakis- [methylene-3- (3 ', 5'-di- 4'-hydroxyphenylpropionate) methane, 1,3,5-tris (3 ', 5'-di-tert- , 6 - (1H, 3H, 5H) thione, paramethoxyphenol, 4-methoxy-1-naphthol, thiodiphenylamine, aluminum salt of N-nitrosophenylhydroxyamine, trade name Adecastab LA -81, trade name ADECASTAB LA-82 (manufactured by Adeka Co., Ltd.), and the like. Of these, radical polymerization inhibitors based on naphthoquinone, hydroquinone, nitroso and piperidine are preferable, and naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-tert- P-cresol, and Polystop 7300P (manufactured by Hakuto Co., Ltd.) are more preferable, and Polystop 7300P (manufactured by Hakuto Co., Ltd.) is most preferable.

The content of the radical polymerization inhibitor is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, and particularly preferably 0.01 to 0.2% by mass in the total amount of the liquid crystal sealing agent of the present invention.

As an example of a method of obtaining the liquid crystal sealing agent of the present invention, there is the following method. First, the component (C) is heated and dissolved in the component (A), if necessary. (B), (D), (E) and a defoaming agent, a leveling agent, a solvent and the like are added, and the mixture is mixed with a known mixing agent For example, a three-roll mill, a sand mill, a ball mill or the like, and then filtered with a metal mesh to produce the liquid crystal sealing agent of the present invention.

A liquid crystal display cell of the present invention is a liquid crystal display device in which a pair of substrates each having a predetermined electrode formed on a substrate are opposed to each other at a predetermined interval and the periphery thereof is sealed with the liquid crystal sealant of the present invention. The type of the liquid crystal to be enclosed is not particularly limited. Here, the substrate is composed of a combination substrate made of glass, quartz, plastic, silicon or the like and having at least one light transmitting property. As a method of manufacturing the liquid crystal display device, a spacer (gap control member) such as glass fiber is added to the liquid crystal sealing material of the present invention, and the liquid crystal sealing material is coated on one side of the pair of substrates using a dispenser or a screen printing apparatus After that, temporary curing is carried out at 80 to 120 캜, if necessary. Thereafter, liquid crystal is dropped on the inner side of the frozen portion of the liquid crystal sealer, and the other glass substrate is superimposed on the vacuum in the vacuum to perform gap insertion. After forming the gap, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130 캜 for 1 to 2 hours. When it is used as a photothermal additive type, ultraviolet rays are irradiated to the liquid crystal seal part by an ultraviolet ray irradiator to cause photo curing. The ultraviolet irradiation dose is preferably an irradiation dose of 500 to 10,000 mJ / cm ² , more preferably 1000 to 6000 mJ / cm ² . Thereafter, if necessary, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130 캜 for 1 to 2 hours. The liquid crystal display cell of the present invention thus obtained is free from display defects due to liquid crystal contamination, and is excellent in adhesion and humidity resistance reliability. Examples of the spacer include glass fibers, silica beads, polymer beads, and the like. The diameter varies depending on the purpose, but is usually 2 to 8 탆, preferably 4 to 7 탆. The amount thereof is usually about 0.1 to 4 mass%, preferably about 0.5 to 2 mass%, and more preferably about 0.9 to 1.5 mass%, based on 100 mass% of the liquid crystal sealing material of the present invention.

The liquid crystal sealing agent of the present invention has an effect of reducing wiring erosion. As a result, driving defects after the humidity test can be eliminated. The cured product is also excellent in low liquid crystal contamination, and further, various cured products such as adhesive strength and heat resistance are excellent. From the above, a liquid crystal display cell having excellent reliability can be realized by using the liquid crystal sealing agent of the present invention. The liquid crystal display cell prepared using the liquid crystal sealing material of the present invention also satisfies the characteristics required for a liquid crystal display cell in which the voltage holding ratio is high and the ion density is low.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. On the other hand, unless otherwise specified, "parts" and "%" in the text are based on mass.

[Synthesis Example 1]

[Synthesis of pre-acrylate of resorcin diglycidyl ether]

[Step 1]

5500 g of resorcin, 37000 g of epichlorohydrin, and 500 g of tetramethylammonium chloride were added to a flask equipped with a thermometer, a dropping funnel, a cooling tube, and a stirrer, and dissolved under stirring. Subsequently, 4000 g of sodium hydroxide on the flakes was added in portions over 100 minutes, followed by further reaction at 70 ° C for 1 hour. After completion of the reaction, 15000 g of water was added and the mixture was washed with water. Then, excess epichlorohydrin and the like were distilled off from the oil layer at 130 ° C under reduced pressure. 22200 g of methyl isobutyl ketone was added to the residue and dissolved, and the temperature was raised to 70 캜. 1000 g of a 30% aqueous sodium hydroxide solution was added under stirring, and the reaction was carried out for 1 hour. Thereafter, the reaction mixture was washed with water 5550 g three times, and methyl isobutyl ketone was distilled off at 180 캜 under reduced pressure to obtain 10550 g of resorcin diglycidyl ether . The epoxy equivalent of the obtained epoxy compound was 129 g / eq.

[Step 2]

181.2 g of the resorcin diglycidyl ether obtained in Synthesis Example 1 was dissolved in 266.8 g of toluene, 0.8 g of dibutylhydroxytoluene as a polymerization inhibitor was added and the temperature was raised to 60 캜. Thereafter, 117.5 g of 100% equivalent of acrylic acid as an epoxy group was added, and the temperature was further raised to 80 캜. To this, 0.6 g of trimethylammonium chloride as a reaction catalyst was added and the mixture was stirred at 98 캜 for about 30 hours. The obtained reaction solution was washed with water and toluene was distilled off to obtain 253 g of the desired acrylic ester of resorcin diglycidyl ether.

[Synthesis Example 2]

[Synthesis of pre-acrylate of bisphenol A type epoxy compound]

282.5 g of bisphenol A type epoxy compound (product name: YD-8125, manufactured by Shin-Nittsu Chemical Co., Ltd.) was dissolved in 266.8 g of toluene, 0.8 g of dibutylhydroxytoluene as a polymerization inhibitor was added and the temperature was raised to 60 캜. Thereafter, 117.5 g of acrylic acid equivalent to 100% of the epoxy group was added and the temperature was further raised to 80 ° C. To the mixture was added 0.6 g of trimethylammonium chloride as a reaction catalyst and the mixture was stirred at 98 ° C for about 30 hours to obtain a reaction solution . The reaction solution was washed with water and toluene was distilled off to obtain 395 g of the desired bisphenol A type epoxy compound acryl ester.

[Synthesis Example 3]

[Synthesis of 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane]

100 parts (0.28 mol) of commercially available benzopinacol (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 350 parts of dimethylformaldehyde. To this was added 32 parts (0.4 mol) of pyridine as a base catalyst and 150 parts (0.58 mol) of BSTFA (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silylating agent, and the mixture was heated to 70 캜 and stirred for 2 hours. The obtained reaction solution was cooled, and 200 parts of water was added with stirring to precipitate the product and inactivate the unreacted silylating agent. The precipitated product was separated by filtration and sufficiently washed with water. The resulting product was then dissolved in acetone and recrystallized with water. 105.6 parts (yield: 88.3%) of the desired 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane was obtained.

Analysis by HPLC (high performance liquid chromatography) showed a purity of 99.0% (area percent).

[Preparation of Examples 1 to 5 and Comparative Examples 1 to 4]

A photo radical polymerization initiator (component (C)) was added to the curable compound (component (A)) such as the compound synthesized in Synthesis Example 1 and the compound synthesized in Synthesis Example 2 at the ratios shown in the following Table 1, Dissolved. And the mixture was cooled to room temperature to obtain a thermally curable resin composition containing a thermal radical polymerization initiator (component B), a silane coupling agent (component F), a thermosetting agent (component E), an organic filler (component D- (Examples 1 to 5 and Comparative Examples 1 to 4) were dispersed by a three-roll mill and filtered with a metal mesh (635 mesh) to obtain a liquid crystal dropping sealing agent (Examples 1 to 5 and Comparative Examples 1 to 4) .

[Absorption rate measurement]

The liquid crystal sealant prepared in Examples and Comparative Examples was sandwiched by a polyethylene terephthalate (PET) film to form a thin film having a thickness of 100 탆, which was cured in an oven at 130 캜 for 1 hour to peel off the PET film after curing to obtain a seal- Thereafter, this was cut into 20 mm x 50 mm short strips to form a sample piece. The obtained sample pieces were stabilized for 24 hours at 25 ° C and 50% RH in accordance with JIS-K7209 D method, and then the initial weight was measured. After the samples were absorbed at 60 ° C and 90% RH for 24 hours, The weight was made after. After the measurement, the absorption rate was calculated by the following formula.

Absorption rate (%) = ((weight after absorption (g) - initial weight (g)) / initial weight (g)

[Measurement of moisture permeability]

A seal cured film was prepared by the same method as the water absorption rate, and cut into a square shape of 90 mm x 90 mm to obtain a sample piece. This sample piece was measured for moisture permeability at a temperature of 60 占 폚 with a moisture permeability measuring device Lyssy L80-5000 manufactured by Systech Illinois according to JIS-K7129 A method.

[Evaluation of electrode corrosion in high temperature and high humidity test]

Using the liquid crystal sealant prepared in the examples and comparative examples, a liquid crystal cell for evaluation having a cell gap of 5 mu m was produced, and the occurrence of electrode corrosion in the high temperature and high humidity test was confirmed. The test method is described below.

0.02 g of glass fiber having a diameter of 5 탆 as a spacer was added to 2 g of the liquid crystal sealant, and the mixture was stirred and defoamed, and filled into a 5 ml syringe. A rectangular seal pattern of 30 mm x 40 mm was applied to a glass substrate with an ITO transparent electrode and then filled with a syringe using a dispenser (SHOTMASTER 300, manufactured by Musashi Engineering Co., Ltd.), and then a liquid crystal MLC-3007 : Manufactured by Merck Co., Ltd.) was dripped into the seal pattern frame. In addition, an in-plane spacer (Natco spacer KSEB-525F: manufactured by Natoco Co., Ltd., gap width of 5 μm after bonding) was dispersed and fixed on another ITO glass substrate, and the liquid- And released to the atmosphere to form a gap. The ultraviolet rays of 500 mJ / cm ² (100 mW / cm ² for 5 seconds) were irradiated with a metal halide lamp (manufactured by Ushio Electric Co., Ltd.) at a low dose of 500 mJ / cm ² , And further put into an oven at 130 DEG C for 1 hour to thermally cure the seal pattern to prepare a liquid crystal cell for evaluation. The resultant liquid crystal cell for evaluation was put into a high-temperature and high-humidity condition of 60 ° C and 90% RH for 240 hours under the condition that a sinusoidal voltage of 10 V 100 Hz was applied to it by a function generator (FG-281 manufactured by Tecio Technology Corporation) The seal portion was observed under a microscope to evaluate the electrode corrosion according to the following criteria.

○: No corrosion of the ITO electrode was observed at the periphery of the seal.

DELTA: Corrosion of the ITO electrode was slightly observed at the periphery of the seal.

X: Corrosion of the ITO electrode was observed at the periphery of the seal.

[Liquid Crystal Pollution Evaluation]

For each of the liquid crystal sealing agents prepared in Examples and Comparative Examples, about 100 mg of a sealing agent was spread on the bottom of a 10 ml vial bottle, and then liquid crystal (MLC-3007, manufactured by Merck Co., Ltd.) , And 10 times the amount of each sealant applied. The resulting vial was heated, held at 130 占 폚 for 1 hour, and then cooled for 30 minutes until it was at room temperature. The supernatant liquid of each liquid crystal was separated by decantation, and the electrical resistance value was measured with a digital ultra-high resistance meter (R8340, manufactured by Advan Test Co., Ltd.), and the determination was made by the following criteria with the specific resistance value against the liquid crystal value without the sealant I did.

O: 5.0 x 10 < ¹² >

DELTA: 5.0 x 10 ¹¹ or more and less than 5.0 x 10 ¹²

×: less than 5.0 × 10 ¹¹

[Evaluation of hardenability of shielding part]

As shown in Fig. 1, a liquid crystal sealant containing 1 wt% of glass fibers of 3 mu m in thickness was applied to the center of a glass substrate etched with chromium plating, and the resultant was adhered using a black matrix substrate as a counter substrate and fixed with a clip Before ultraviolet irradiation). After irradiating ultraviolet rays of 3000 mJ / cm ² from the side of the glass substrate on which chromium was etched, the two bonded substrates were peeled off, and a portion shielded from light under the chromium was observed with a microscope to measure the curing width of the light shielding portion .

?: 30 占 퐉 or more

DELTA: 10 m or more and less than 30 m

×: less than 10 μm

From the results shown in Table 1, Examples 1 to 5, in which the water absorption rate and moisture permeability of the cured product by heat alone were not more than a certain level, showed no wire corrosion and excellent low-liquid crystal contamination. On the other hand, the liquid crystal sealing agent described in the comparative example has wiring corrosion, and there is a problem in the long-term reliability of the liquid crystal display cell. From this, it can be said that the present invention is a liquid crystal sealing agent having excellent reliability after the humidity resistance test, and that the reliability of the liquid crystal display cell manufactured using the liquid crystal sealing cell is also excellent.

The liquid crystal sealing agent of the present invention has a very small effect on the liquid crystal display characteristics, and thus makes it possible to make the liquid crystal display element high-precision, high-speed response, low voltage driving, and long life. In addition, since the adhesive strength and humidity resistance reliability are excellent, it is possible to realize a liquid crystal display device with high reliability.

Claims (14)

(A) a curable compound,
Without irradiation with ultraviolet rays and at 130 ℃ below the measured absorption rate in accordance with a first time series only did the cured product, JIS-K7209 curing of 2.0%, a liquid crystal dropping a water vapor transmission rate of not more than 130g / m ² * 24h measured according to JIS-K7129 Liquid crystal sealant for construction method. The method according to claim 1,
Further, a liquid crystal sealing agent for a liquid crystal dropping process containing (B) a thermal radical polymerization initiator. 3. The method according to claim 1 or 2,
Wherein the thermal radical polymerization initiator (B) is a thermal radical polymerization initiator not containing an oxygen-oxygen bond (-OO-) and a nitrogen-nitrogen bond (-N = N-) in the molecule. 4. The method according to any one of claims 1 to 3,
(C) a liquid crystal sealing agent for liquid crystal dropping process containing a photo radical polymerization initiator. 5. The method according to any one of claims 1 to 4,
A liquid crystal sealing agent for liquid crystal dropping method, further comprising (D) a filler, wherein the content of the filler in the total amount of the liquid crystal sealing agent is 20 mass% or more. 6. The method according to any one of claims 1 to 5,
Wherein the component (D) is a mixture of (D-1) an organic filler and (D-2) an inorganic filler. 7. The method according to any one of claims 1 to 6,
And a content of the inorganic filler in the total amount of the liquid crystal sealing agent of the component (D-2) is 20 mass% or more. 8. The method according to any one of claims 1 to 7,
Wherein the component (A) curable compound is an epoxy (meth) acrylate compound. 8. The method according to any one of claims 1 to 7,
Wherein the component (A) curable compound is a mixture of an epoxy (meth) acrylate compound and an epoxy compound. 10. The method according to any one of claims 1 to 9,
Further, a liquid crystal sealing agent for a liquid crystal drip tray containing (E) a thermosetting agent. 11. The method of claim 10,
Wherein the component (E) thermosetting agent is an organic acid hydrazide. 12. The method according to any one of claims 1 to 11,
A liquid crystal sealing agent for liquid crystal dropping method further comprising (F) a silane coupling agent. A liquid crystal display cell comprising two substrates, wherein a liquid crystal is dropped into the inner side of a weir of a liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 12 formed on one substrate And then the other substrate is cemented and then cured by light and / or heat. A liquid crystal display cell sealed with a cured product obtained by curing the liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 12.

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