TW201428009A - Liquid-crystal sealing agent and liquid-crystal display cell using same - Google Patents

Abstract

Provided is a liquid-crystal sealing agent for a liquid-crystal dripping process having extremely low contamination of the liquid crystal throughout the step because of the speed of the reaction using heat, and having excellent handling properties and storage stability. This liquid-crystal sealing agent for a liquid-crystal dripping process contains: (a) a thermal radical polymerization initiator;(b)a radical polymerization preventing agent;(c) a curable resin having a (meth)acryloyl group and (d) an organic filler, component (b) being expressed by any of formulas (1)-(3), or having a piperidine skeleton. In the formulas, R1, R2, R4, and R5 represent a hydrogen atom or a methyl group, and R3 and R6 represent a hydroxy group or a C1-4 alkyl group. Note that one of -OR1, -OR2, and -R3, and one of -OR4, -OR5, and -R6 is a hydroxy group. R7 represents a hydrogen atom, a hydroxy group, or a C1-4 alkyl group.

Description

Liquid crystal sealing agent and liquid crystal display unit using the liquid crystal sealing agent

The present invention relates to a liquid crystal sealant for a liquid crystal dropping method which can be hardened only by heat. More specifically, a liquid crystal sealing agent for a liquid crystal dropping method which is excellent in properties of a cured product having excellent heat hardenability by heat, handling property, storage stability, adhesive strength, and the like, A method for producing the same, and a liquid crystal display cell (liquid crystal display cell) obtained by sealing the cured product.

In recent years, with the increase in the size of the liquid crystal display unit, a so-called "liquid crystal dropping method" having a higher mass productivity has been proposed as a method of manufacturing a liquid crystal display unit (see Patent Documents 1 and 2). Specifically, in this method, after the liquid crystal is dropped into the inside of the weir formed by the liquid crystal sealing agent formed on one substrate, the other substrate is bonded, thereby producing a liquid crystal display sealed with liquid crystal. unit.

At present, a liquid crystal sealing agent for a liquid crystal dropping method is a light-heat combination and has been put into practical use (Patent Documents 3 and 4). In the liquid crystal dropping method using the liquid crystal sealing agent, the liquid crystal sealing agent held by the substrate is irradiated with light to be primary cured, and then heated to be secondary hardened. According to this method, the uncured liquid crystal sealing agent can be quickly cured by light, and the dissolution (elution) of the liquid crystal sealing agent component to the liquid crystal can be suppressed. In addition, when it is only photohardening, there is a problem that the adhesion strength due to curing shrinkage or the like is insufficient at the time of photocuring. However, if it is a photothermal type, it may have secondary hardening by heating. Can solve the advantages of these problems.

However, in recent years, with the miniaturization of the liquid crystal display element, the metal wiring portion of the array substrate of the liquid crystal display element, or the black matrix portion of the color filter substrate, cannot be exposed. The light-shielding portion of the liquid crystal sealing agent makes the problem of poor display in the vicinity of the seal become more serious than before. That is, due to the presence of the light shielding portion, the primary hardening by the above-described light becomes insufficient, so that a large amount of unhardened components remain in the liquid crystal sealing agent. In this state, when the secondary hardening step by heat is entered, the dissolution of the uncured component with respect to the liquid crystal is promoted by heat, resulting in poor display in the vicinity of the seal.

In order to solve this problem, there has been proposed a proposal to increase the rate of hardening by heat to reduce the dissolution of components by using a thermal radical generating agent. Further, there is a proposal to apply the technique to realize a liquid crystal dropping method only by heat (Patent Documents 5 and 6).

It is an ideal method to achieve uniform hardening of the liquid crystal sealing agent without being affected by the above-mentioned light-shielding portion by a hot liquid crystal dropping method, but it is faced with, for example, a phenomenon called "liquid crystal incorporation phenomenon". Difficult problem. The "liquid crystal doping phenomenon" is caused by the low viscosity of the uncured liquid crystal sealing agent in the thermal curing stage, and the heat-expanded liquid crystal exerts a pressure thereon to cause liquid crystal to be incorporated into the liquid crystal sealing agent. When this occurs, the contact area between the liquid crystal sealing agent and the upper and lower substrates becomes small, and the adhesion is remarkably lowered. Further, depending on the case, there is a case where the liquid crystal leaks out through the liquid crystal sealing agent.

In order to solve this problem, a method of lowering the hardening start temperature of the above-described thermal radical generating agent or increasing the amount of addition or the like to accelerate the curing rate can be considered. However, this method will become a problem due to the speed of its reaction and the decrease in operational usability. The term "operability" means the ease with which a liquid crystal sealing agent is used. For example, in a degassing process of a liquid crystal sealing agent, or a spacers agent mixing process, etc., in a step of being placed under a vacuum or subjected to heat, the liquid crystal sealing agent is hardened. , or the phenomenon of gelation, in this application, the difficulty level of this phenomenon is defined as "Operational usability." Therefore, it is considered that the liquid crystal sealing agent which is not easy to be used for gelation and which is likely to cause gelation is considered to be a liquid crystal sealing agent which is inferior in handling property.

Further, in addition to the above-described operational usability, storage stability is also an important characteristic of the liquid crystal sealing agent. This is a property in which sealing coating becomes difficult due to an increase in viscosity at room temperature, and a liquid crystal sealing agent using a thermal radical generating agent is also inferior in storage stability. The method for solving this problem has been proposed in Patent Document 7, but it is not sufficient as a solution to all of the above problems.

As described above, although the liquid crystal sealing agent for liquid crystal dropping method has been developed very actively, it has excellent thermal reactivity or shading portion hardenability and can simultaneously achieve workability, storage stability, and the like, and excellent in cured properties. The liquid crystal sealant has not been realized.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 63-179323

Patent Document 2: Japanese Laid-Open Patent Publication No. 10-239694

Patent Document 3: Japanese Patent No. 3583326

Patent Document 4: Japanese Laid-Open Patent Publication No. 2004-61925

Patent Document 5: Japanese Laid-Open Patent Publication No. 2004-126211

Patent Document 6: Japanese Patent Laid-Open Publication No. 2009-8754

Patent Document 7: Japanese Laid-Open Patent Publication No. 2009-42409

The invention relates to a liquid crystal sealing agent used in a liquid crystal dropping method, wherein a liquid crystal dropping method is: after a liquid crystal sealing agent is formed on a substrate, a liquid crystal sealing agent is dripped into a liquid crystal, and the other substrate is bonded to seal the liquid crystal. The agent portion is hardened only by heating to manufacture a liquid crystal display unit. The liquid crystal sealing agent proposed by the present invention has a rapid reaction by heat, extremely low contamination to liquid crystals in the entire step, and excellent liquid crystal sealing agent resistance to dehydration, degassing, etc. It is also excellent in workability, and excellent in coating properties, adhesion, adhesion strength, and the like of the substrate, and thus can be applied to any liquid crystal panel of any design.

As a result of intensive studies, the present inventors have found that a liquid crystal sealing agent which combines a thermal radical polymerization initiator with a specific radical polymerization inhibitor and an organic filler can simultaneously achieve the above-described thermal reactivity and handling property. As a result, the liquid crystal contamination property can be suppressed, and the incorporation phenomenon is less likely to occur, and the cured product properties such as the adhesive strength are also excellent, and the present invention has been completed based on the findings.

That is, the present invention relates to the following 1) to 15). In addition, in this In the specification, the term "(meth)acryloyl" means one or both of "acryloyl" and "methacryl". Similarly, in the present specification, the term "(meth)acrylic" means one or both of "acrylic" and "methacrylic".

1) A liquid crystal sealing agent for a liquid crystal dropping method, comprising: (a) a thermal radical polymerization initiator, (b) a radical polymerization inhibitor, (c) a curable resin having a (meth) acrylonitrile group, and (d) an organic filler, and the above component (b) is a radical polymerization inhibitor represented by any one of the following formulas (1) to (3), or a radical polymerization having a piperidine skeleton Inhibitor:

(In the formula (1), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and R ³ represents a hydroxyl group or a C1-C4 alkyl group, wherein -OR ¹ , -OR ² , and -R ³ Either hydroxy);

(In the formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyl group or a C1-C4 alkyl group, wherein -OR ⁴ , -OR ⁵ , and -R ⁶ Either hydroxy);

(In the formula (3), R ⁷ represents a hydrogen atom, a hydroxyl group, or a C1-C4 alkyl group).

(2) The liquid crystal sealing agent for liquid crystal dropping method according to the above 1), wherein the radical polymerization inhibitor having a piperidine skeleton is a radical polymerization inhibitor represented by the following formula (4):

(In the formula (4), the group A represents a hydrogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amine group, a C1-C4 alkoxy group, a phenoxy group, an ethenyl group (-NHCOCH ₃ ), a benzamidine group. (-OCOC ₆ H ₅ ), isothiocyanato group (-NCS), oxo group (=O), or any of the following formulas (5) to (7) The base represented by the formula; the base B represents a hydrogen atom, an oxygen atom, a C1-C4 alkyl group, or a C1-C20 alkoxy group; wherein, in the case of an oxygen atom, a NO is a nitroso group. ; R ⁸ to R ¹⁵ are each independently represent a C1-C4 alkyl group;

(in the formula (5), * means a bonding site);

(in the formula (6), * means a bonding position, the base C means the same as the above-mentioned base B, and R ¹⁶ to R ¹⁹ each independently represent a C1-C4 alkyl group);

(In the formula (7), * means a bonding position, a group D means the same as the above-mentioned group B, R ²⁰ represents a C1-C20 alkylene group, and R ²¹ to R ²⁴ each independently represent a C1-C4 alkyl group. ).

(3) The liquid crystal sealing agent for liquid crystal dropping method according to the above 1), wherein the component (d) is rubber fine particles.

(4) The liquid crystal sealing agent for liquid crystal dropping method according to any one of the above-mentioned, wherein the component (d) is selected from the group consisting of acrylic rubber (acrylic rubber), styrene rubber, At least one or more rubber fine particles of the group consisting of styrene olefin rubber and silicone rubber.

(5) The liquid crystal sealing agent for liquid crystal dropping method according to any one of the above-mentioned items 1 to 4, wherein the component (c) is a (meth)acryl fluorenyl group and has a resorcinol skeleton hardening. Resin.

(6) The liquid crystal sealing agent for liquid crystal dropping method according to any one of the above-mentioned items 1 to 5, wherein the component (c) contains three or more (meth) acrylonitrile groups in one molecule. A curable resin of a compound.

The liquid crystal sealing agent for liquid crystal dropping method according to any one of the above-mentioned, wherein the component (a) has no oxygen-oxygen bond (-OO-) or nitrogen in the molecule. a thermal radical polymerization initiator of a nitrogen bond (-N=N-).

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of the above-mentioned, further comprising (e) a curable resin having an epoxy group and (f) a thermosetting agent.

9) The liquid crystal sealing agent for liquid crystal dropping method according to the above 8), wherein the component (f) is an organic acid hydrazide.

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of the above 1 to 9, further comprising (g) a decane coupling agent.

The liquid crystal sealing agent for a liquid crystal dropping method according to any one of the above-mentioned items 1 to 10, further comprising (h) an inorganic filler.

(12) The liquid crystal sealing agent for liquid crystal dropping method according to the above (8), wherein when the total amount of the component (c) and the component (e) is 100 parts by mass, the content of the component (b) is It is 0.0001 to 1 part by mass.

13) A method for producing a liquid crystal sealing agent for a liquid crystal dropping method, which is a system The method for producing a liquid crystal sealing agent for a liquid crystal dropping method according to any of the above 1 to 12, comprising the step of dissolving the component (b) in the component (c).

And a method for producing a liquid crystal sealing agent for a liquid crystal dropping method according to the above 8) or 9), which comprises dissolving the component (b) in the above component (e) The steps in ).

And a liquid crystal display unit obtained by the liquid crystal sealing agent for liquid crystal dropping method according to any one of the above 1) to 12), or the liquid crystal obtained by the manufacturing method according to the above 13) or 14) The method is obtained by curing a cured product obtained by a liquid crystal sealing agent and sealing it.

The liquid crystal sealing agent for liquid crystal dropping method of the present invention can be applied to a liquid crystal dropping method in which only a liquid crystal sealing agent is cured by heat, because the curing speed at the time of thermal curing is fast. Therefore, the degree of freedom of the wiring design of the panel can be ensured, and the highly reliable liquid crystal display panel can be easily manufactured. Further, in the manufacturing step of the liquid crystal display unit, since the step of irradiating light such as ultraviolet rays can be omitted, it contributes to improvement in production efficiency.

The (a) thermal radical polymerization initiator used in the present invention is not particularly limited as long as it is a compound capable of generating a radical by heating to initiate a chain polymerization reaction. The organic peroxide, the azo compound, the benzoin compound, the benzoin ether compound, the acetophenone compound, the benzopinacol, etc.; benzo pinacol is suitable for use.

For example, as an organic peroxide, Kayamekku ^RTM A, M, R, L, LH, SP-30C, Padokkusu CH-50L, BC-FF, Kadokkusu B-40ES, Padokkusu 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, Padokkusu 16, Kaya carvone ^RTM BIC-75, AIC-75 (above is Kayaku Akzo Co., Ltd.); Pamekku ^RTM N, H, S, F, D, G, Perhexa ^RTM H, HC, TMH, C, V, 22, MC, Percure ^RTM AH, AL, HB, Perbutyl ^RTM H, C, ND, L, Percumyl ^RTM H, D, Parloyl ^RTM IB, IPP, Perocta ^RTM ND (above is Japan Oils and Fats Co., Ltd. ( NOF Corporation), etc. are available from commercial products. Further, as an azo compound, VA-044, V-070, VPE-0201, VSP-1001 (the above is manufactured by Wako Pure Chemical Industries, Ltd.) and the like are commercially available. commodity. In addition, in this specification, the superscript ^RTM means a registered trademark.

As the (a) thermal radical polymerization initiator, a thermal radical polymerization initiator which does not have an oxygen-oxygen bond (-OO-) or a nitrogen-nitrogen bond (-N=N-) in the molecule is preferable. . a thermal radical polymerization initiator having an oxygen-oxygen bond (-OO-) or a nitrogen-nitrogen bond (-N=N-) in a molecule, since a large amount of oxygen or nitrogen is generated during radical generation, The curing is performed in a state in which air bubbles remain in the liquid crystal sealing agent, and the characteristics such as the adhesion strength are lowered. Among them, a benzopinacol (tetraphenyl-1,2-ethanediol, benzopinacol)-based thermal radical polymerization initiator (including a substance which chemically reforms benzopinacol) is particularly suitable for use. Specifically, benzo pinacol, 1,2-dimethoxy-1,1,2,2-tetraphenylethane, 1,2-diethoxy-1,1,2 ,2-tetraphenylethane, 1,2-diphenoxy-1,1,2,2-tetraphenylethane, 1,2-dimethoxy-1,1,2,2-tetra (4-methylphenyl)ethane, 1,2-diphenoxy-1,1,2,2-tetrakis(4-methoxyphenyl)ethane, 1,2-bis(trimethyl)矽oxy)-1,1,2,2-tetraphenylethane, 1,2-bis(triethyldecyloxy)-1,1,2,2-tetraphenylethane, 1,2 - bis(tertiary butyl dimethyl decyloxy)-1,1,2,2-tetraphenylethane, 1-hydroxy-2-trimethyl decyloxy-1,1,2,2- Tetraphenylethane, 1-hydroxy-2-triethyldecyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-tributylbutyloxycarbonyl- 1,1,2,2-tetraphenylethane, etc.; preferably 1-hydroxy-2-trimethyldecyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2 -Triethyl decyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-tributyl butyl methoxyl-1,1,2,2-tetraphenyl Ethane, 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane; more preferably 1-hydroxy-2-trimethyloxime Base-1,1,2,2-tetraphenylethane, 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane; particularly preferably 1,2 - bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane.

The above benzopinacol has been marketed by Tokyo Chemical Industry Co., Ltd., and Wako Pure Chemical Industries Co., Ltd., and the like. Further, the etherification of the hydroxyl group of benzopinacol can be easily synthesized by a conventional method. Further, by subjecting a hydroxyl group of benzopinacol to a decyl etherification, a corresponding base such as pyridine or the like may be used, and a base such as pyridine or the like may be used. Syntheticly obtained by heating in the presence of a basic catalyst.

Examples of the decylating agent include trimethylchlorodecane (TMCS), hexamethyldioxane (HMDS), and N,O-bis(trimethyldecyl) of a conventional trimethylsulfonating agent. Trifluoroethylamine (BSTFA), triethylchlorodecane (TECS) of a triethylsulfonating agent, or tertiary butylmethyldecane (TBMS) of a tertiary dimethyl dimethyl methacrylate. These reagents are readily available in the market for manufacturers of hydrazine derivatives and the like. The reaction amount of the alkylating agent is preferably 1.0 to 5.0 moles, more preferably 1.5 to 3.0 moles per mole of the hydroxyl group of the target compound. If it is less than 1.0 times of moles, thermal decomposition is promoted due to poor reaction efficiency and long reaction time. If it is more than 5.0 times the mole, it will cause poor separation or refining when it is recycled and reused.

The (a) thermal radical polymerization initiator preferably has a fine particle diameter and is uniformly dispersed. When the average particle diameter is too large, it is preferable that it is 5 μm or less, and more preferably 5 μm or less, in order to prevent the formation of a gap in the case where the upper and lower glass substrates are bonded together. 3 μm or less. Further, although it may be tapered indefinitely, the lower limit is usually about 0.1 μm. The particle size is laser diffraction/scattering particle size distribution measuring apparatus (dry type) (made by Seishin Enterprise Co., Ltd.; LMS-30). Determination.

When the total amount of the curable resin of the liquid crystal sealing agent of the present invention is 100 parts by mass, the content of the thermal radical polymerization initiator (a) is preferably 0.0001 to 10 parts by mass, more preferably 0.0005 to 5 parts by mass. It is particularly preferably 0.001 to 3 parts by mass. In addition, the "curable resin" is a component (e) which is a representative component (c) and is contained as needed. The same applies in this application.

Further, the (b) radical polymerization inhibitor used in the present invention is a radical polymerization inhibitor represented by any one of the above formulas (1) to (3), or a radical polymerization having a piperidine skeleton Inhibitor. These radical polymerization inhibitors may be used singly or in combination of two or more.

The compound represented by the above formula (1) has a high polarity and a low compatibility with respect to a liquid crystal because it has a hydroxyl group. Therefore, even if it is only by the hot liquid crystal dropping method, even if it is directly contacted with the liquid crystal and heated, it is hard to be dissolved in the liquid crystal and is less likely to contaminate the liquid crystal. Further, the compound represented by the above formula (2) or (3) has a high polarity, a large molecular weight, and low compatibility with a liquid crystal. Therefore, even if it is only by the hot liquid crystal dropping method, even if it is directly contacted with the liquid crystal and heated, it is hard to be dissolved in the liquid crystal and is less likely to contaminate the liquid crystal. Further, when compared with other high molecular weight radical polymerization inhibitors, the polymerization inhibition ability is also high. That is, in the liquid crystal dropping method by only heat, it is called a particularly excellent radical polymerization inhibitor.

In the above formula (1), R ¹ and R ² each independently represent a hydrogen atom or a methyl group.

Further, in the above formula (1), R ³ represents a hydroxyl group or a C1-C4 alkyl group. Here, the C1-C4 alkyl group may be a straight chain or a branched chain, and examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a tertiary butyl group and the like. Among these, a methyl group is preferred.

Among them, any of -OR ¹ , -OR ² , and -R ³ is a hydroxyl group. That is, for example, when R ¹ is a methyl group and R ³ is a methyl group, R ² will become a hydrogen atom.

In the above formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group.

Further, in the above formula (2), R ⁶ represents a hydroxyl group or a C1-C4 alkyl group. Here, the C1-C4 alkyl group means a substance which is the same as R ³ in the above formula (1) and preferably contains the same.

Among them, any of -OR ⁴ , -OR ⁵ , and -R ⁶ is a hydroxyl group. That is, for example, when R ⁴ is a methyl group and R ⁶ is a methyl group, R ⁴ will become a hydrogen atom.

In the above formula (3), R ⁷ represents a hydrogen atom, a hydroxyl group, or a C1-C4 alkyl group. Here, the C1-C4 alkyl group means a substance which is the same as R ³ in the above formula (1) and preferably contains the same.

Among these, R ^{7 is} preferably a hydrogen atom or a hydroxyl group, and particularly preferably a hydroxyl group.

On the other hand, a radical polymerization inhibitor having a piperidine skeleton has a property of having low solubility to a liquid crystal, and is a step of heating by direct contact with a liquid crystal, for example, by a hot liquid crystal dropping method. It is not easily dissolved in the liquid crystal and is less likely to contaminate the liquid crystal. Further, when compared with other high molecular weight radical polymerization inhibitors, the polymerization inhibition ability is also high. That is, it is an excellent radical polymerization inhibitor in the liquid crystal dropping method by only heat.

In the radical polymerization inhibitor having a piperidine skeleton, the above formula (4) The representative is excellent in the effect of the present invention.

In the above formula (4), the group A represents a hydrogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amine group, a C1-C4 alkoxy group, a phenoxy group, an ethenyl group (-NHCOCH ₃ ), a benzamidine group. (-OCOC ₆ H ₅ ), an isothiocyanate group (-NCS), a pendant oxy group (=O), or a group represented by any one of the above formulae (5) to (7).

In the above formula (4), the group B represents a hydrogen atom, an oxygen atom, a C1-C4 alkyl group, or a C1-C20 alkoxy group; and in the case of an oxygen atom, it becomes a nitroso group due to N-O.

Here, the C1-C4 alkyl group may be a straight chain or a branched one, and examples thereof include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a tertiary butyl group and the like. Among these, a methyl group is preferred.

The C1-C20 alkoxy group may be a straight chain or a branched chain, preferably a linear one, preferably a C5-C15 alkoxy group, more preferably a C7-C12 alkoxy group.

In the above formula (4), R ⁸ to R ¹⁵ each independently represent a C1-C4 alkyl group. The C1-C4 alkyl group means a substance which is the same as the C1-C4 alkyl group in the above-mentioned group B, and preferably contains the same.

In the above formula (6), the group C is the same as the above-mentioned group B, and R ¹⁶ to R ¹⁹ each independently represent a C1-C4 alkyl group. The C1-C4 alkyl group means a substance which is the same as the C1-C4 alkyl group in the above-mentioned group B, and preferably contains the same.

In the above formula (7), the group D is the same as the above-mentioned group B, R ²⁰ represents a C1-C20 alkyl group, and R ²¹ to R ²⁴ each independently represent a C1-C4 alkyl group.

The C1-C20 alkylene group in R ²⁰ may be a straight chain or a branched chain, preferably a linear one, preferably a C5-C15 alkylene group, more preferably a C7-C12 alkylene group.

The C1-C4 alkyl group in R ²¹ to R ²⁴ means the same as the C1-C4 alkyl group in the above-mentioned group B, and preferably the same.

The radical polymerization inhibitor represented by the above formula (4), for example, POLYSTOP ^RTM 7300 (manufactured by Hakuto Co., Ltd.); ADEKA STAB ^RTM LA-81, LA-82 (above is Asahi Kasei) Industrial Co., Ltd. (made by ADEKA Corporation); TINUVIN ^RTM 123, 765 (above, manufactured by BASF Corporation) and the like are readily available from the market.

The above (b) radical polymerization inhibitor may be added to the component (c) and/or component (e) and dissolved in the case of synthesizing the component (c), but in order to obtain For the effective effect, it is preferred to adopt a method of adding and dissolving the component (c) and/or the component (e).

The content of the above (b) radical polymerization inhibitor, when the present invention is When the total amount of the curable resin in the liquid crystal sealing agent is 100 parts by mass, it is preferably 0.0001 to 1 part by mass, more preferably 0.001 to 0.5 part by mass, and particularly preferably 0.01 to 0.2 part by mass. If the radical polymerization inhibitor is too small, sufficient workability cannot be obtained, and if it is too much, liquid crystal contamination due to thermal reaction delay may become a problem.

The liquid crystal sealing agent of the present invention is a curable resin containing (c) a (meth) acrylonitrile group. Examples of such a curable resin include (meth)acrylic ester, epoxy (meth)acrylate, and the like.

Examples of the (meth) acrylate type include benzyl methacrylate, cyclohexyl methacrylate, glyceryl dimethacrylate, glycerol triacrylate, and EO-modified glycerol triacrylate. Ester, neopentyl acrylate, trimethylolpropane triacrylate, hexyl hydroxyacetate, hexaerythritol hexaacrylate, fluoroglycinol triacrylate )Wait.

The (meth)acrylic acid epoxy ester is obtained by a known method from the reaction of an epoxy resin with (meth)acrylic acid. The epoxy resin as a raw material is not particularly limited, and is preferably a difunctional or higher epoxy resin, and examples thereof include a bisphenol A epoxy resin, a bisphenol F epoxy resin, and a bisphenol S ring. Oxygen resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, aliphatic chain Epoxy resin, Glycidyl ester type epoxy resin, epoxy propyl amine type epoxy resin, hydantoin type epoxy resin, isocyanurate type Epoxy resin), a phenol novolac type epoxy resin having a trisphenol methane skeleton; and other, di-epoxypropyl ether compounds of difunctional phenols such as catechol (catechol) and resorcinol Diethylene oxide propyl ethers of difunctional alcohols, and such halides, hydrogenated products, and the like. Among these, from the viewpoint of liquid crystal contamination, an epoxy resin having a resorcinol skeleton such as resorcinol diepoxypropyl ether is preferred. Further, the ratio of the epoxy group to the (meth) acrylonitrile group is not particularly limited, and can be appropriately selected from the viewpoints of process compatibility and liquid crystal contamination.

Therefore, a preferred curable resin having a (meth) acrylonitrile group is a curable resin having a (meth) acrylonitrile group and having a resorcinol skeleton, for example, resorcinol diglycidyl ether. Acrylate, or methacrylate of resorcinol diglycidyl ether.

In the liquid crystal sealing agent of the present invention, the component (c) preferably contains a compound having three or more (meth)acrylonium groups in one molecule. A compound having three or more (meth) acrylonitrile groups in one molecule can achieve excellent resistance to incorporation due to a high crosslinking rate (reaction rate). In addition, when this method is used, it is different from the method of increasing the amount of the thermal radical polymerization initiator and the like to improve the reactivity, and the workability is also excellent.

Examples of the compound having three or more (meth)acryl fluorenyl groups in one molecule include KAYARAD ^RTM PET-30, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, and DPEA-12. GPO-303, TMPTA, THE-330, TPA-320, TPA-330, D-310, D-330, RP-1040, UX-5000, DPHA-40H (above is Nippon Kayaku Co.) .,Ltd.)); NK Ester ^RTM A-9300, A-9300-1CL, A-GLY-9E, A-GLY-20E, A-TMM-3, A-TMM-3LM-N, A-TMPT , AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH (above is Shin-Nakamura Chemical Co., Ltd.); SR295, SR350, SR355, SR399, SR494, CD501, SR502, CD9021, SR9035, and SR9041 (the above is manufactured by SARTOMER Co., Ltd.). Among these, those having a molar average molecular weight of 800 or more, such as KAYARAD ^RTM DPCA-20, DPCA-30, and DPEA-12, are preferred. Further, a curable resin containing a C1-C4 alkylene oxide (-ORO-) in a molecule is preferable, and KAYARAD ^RTM DPEA-12 is particularly preferable.

When the total amount of the liquid crystal sealing agent is 100 parts by mass, the content of the curable resin having a (meth) acrylonitrile group is preferably 30 to 90 parts by mass, more preferably 50 to 90. Parts by mass.

The liquid crystal sealing agent of the present invention further comprises (d) an organic filler . Examples of the organic filler include polyamide fine particles such as nylon 6, nylon 12, and nylon 66; fluorine-based fine particles such as tetrafluoroethylene and vinylidene fluoride; and olefin-based fine particles such as polyethylene and polypropylene; Polyester fine particles such as ethylene phthalate or polyethylene naphthalate; rubber fine particles such as natural rubber, isoprene rubber, and acrylic rubber.

Among them, as the organic filler, rubber fine particles are preferable. Examples of the rubber fine particles include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene ‧ butadiene rubber (SBR), and butyl rubber (IIR). Nitrile rubber (NBR), ethylene ‧ propylene rubber (EPM, EP), chloroprene rubber (CR), acrylic rubber (ACM, ANM), chlorosulfonated polyethylene rubber (CSM), urethane Rubber (PUR), silicone rubber (Si, SR), fluororubber (FKM, FPM), polysulfide rubber (thiokol), etc., may be individual rubber particles or two or more Comes as a core-shell structure. In addition, two or more types may be used in combination. Among these, an acrylic rubber, a styrene rubber, a styrene olefin rubber, or a silicone rubber is preferable, and an acrylic rubber or a silicone rubber is particularly preferable.

In the case of using an acrylic rubber, it is preferably a case of an acrylic rubber having a core-shell structure composed of two kinds of acrylic rubbers, and preferably the core layer is n-butyl acrylate and the shell layer is methyl methacrylate. By. This is ZEFIAC ^RTM F-351, which has been marketed by AICA Kogyo Co., Ltd.

Further, examples of the above-mentioned silicone rubber include an organic polyoxyalkylene crosslinked product powder, a linear polydimethylsiloxane crosslinked product powder, and the like. Further, examples of the composite polyoxyxene rubber include a coating of a silicone resin (for example, a polyorganosilsesquioxane resin) on the surface of the above polyoxyethylene rubber. Among these rubber fine particles, a composite of a polyfluorene rubber which is a crosslinked powder of a linear polydimethyl siloxane or a crosslinked powder of a linear polydimethyl siloxane which is coated with a polyoxyn oxy resin Polyoxyethylene rubber microparticles. These may be used singly or in combination of two or more. Further, the shape of the rubber powder is preferably a spherical shape in which the viscosity after the addition is increased to a small amount.

When the total amount of the liquid crystal sealing agent is 100 parts by mass, the content of the organic filler (d) is preferably 5 to 50 parts by mass, more preferably 5 to 40 parts by mass.

In the liquid crystal sealing agent of the present invention, (e) a curable resin having an epoxy group is further used, whereby an increase in adhesion strength can be expected. The curable resin having an epoxy group is not particularly limited, and is preferably a difunctional or higher epoxy resin, and examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol S. Epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, fat Family Chain epoxy resin, epoxy propyl ester epoxy resin, epoxy propyl amine epoxy resin, beta-urea urea (hydantoin) epoxy resin, isocyanurate epoxy resin, with three a phenol novolak type epoxy resin having a phenol methane skeleton; other being a difunctional phenolic diepoxypropyl etherate, a difunctional alcoholic diepoxypropyl etherate, and such a halide and hydrogenation Things and so on. Among these, from the viewpoint of liquid crystal contamination, a bisphenol epoxy resin or a novolak epoxy resin is preferred.

When the total amount of the liquid crystal sealing agent is 100 parts by mass, the content of the epoxy resin having an epoxy group is preferably 1 to 30 parts by mass.

In the liquid crystal sealing agent of the present invention, the (f) thermal curing agent to be used together with the component (e) is not particularly limited, and examples thereof include polyamines, polyhydric phenols, anthraquinone compounds, and the like, but are particularly suitable for use in a solid state. Organic sour. For example, an aromatic cerium strontium sulphate, bismuth benzoate, bismuth 1-naphthoate, diterpene terephthalate, diterpene isophthalate, 2,6-naphthoic acid Bismuth, 2,6-pyridine dioxime, 1,2,4-benzenetriazole, tetramethylphosphonium tetradecanoate, tetraterpene pyromboxene, and the like. Further, in the case of an aliphatic hydrazine compound, for example, formhydrazide, acetohydrazide, strontium propionate, bismuth oxalate, diammonium malonate, succinic acid may be mentioned. Diterpenoid, diammonium glutarate, diammonium adipate, dipimepyridinium diphosphate, diterpene sebacate, 1,4-cyclohexanedioxime, ditartrate tartrate, malic acid Diterpenoid, iminodiacetic acid dioxime, N,N'-hexamethylene bissemicarbazide, triterpene citrate, nitriloacetic acid trihydrazide, tricyclohexane tricarboxylic acid; An intramethylene uregar skeleton such as 1,3-bis(diaminocarbonylethyl)-5-isopropylhydantoin, preferably having a valine hydantoin skeleton (B) a diterpene compound having a skeleton in which a carbon atom of an internal uretone ring is substituted with an isopropyl group; ginseng (1-aminoaminocarbonylmethyl)isocyanurate, ginseng (2-aminoaminocarbonylethyl) Isocyanurate, ginseng (2-diaminocarbonylethyl)isocyanurate, ginseng (3-aminoaminopropyl)isocyanurate, bis(2-aminoaminocarbonyl) Base) isocyanurate. These heat hardeners may be used singly or in combination of two or more. From the viewpoint of hardening reactivity and potential balance, it is preferably diammonium isophthalate, diammonium malonate, diammonium adipate, diterpene sebacate, and ginseng ( 1-Aminocarbonylcarbonylmethyl)isocyanurate, ginseng (2-aminoaminocarbonylethyl)isocyanurate, ginseng (2-aminoaminocarbonylethyl)isocyanurate, ginseng (3-Diaminocarbonylpropyl)isocyanurate, particularly preferably diammonium malonate or diterpene sebacate.

The amount of use of the above (f) thermal curing agent is 0.5 to 2.0 equivalents, preferably 0.8 to 1.2 equivalents, when the epoxy group of the component (e) is 1 equivalent.

In the liquid crystal sealing agent of the present invention, by using the (g) decane coupling agent, it is expected that the adhesion strength is improved or the moisture resistance reliability is improved. As a decane coupling The mixture may, for example, be 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 3-glycidoxypropylmethyldiethoxylate Baseline, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, N-phenyl-γ-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3 -Aminopropylmethyldimethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-amino Propylmethyldimethoxydecane, 3-aminopropyltriethoxydecane, 3-hydrothiopropyltrimethoxydecane, vinyltrimethoxydecane, N-(2-(vinylbenzene) Methylamino)ethyl)-3-aminopropyltrimethoxydecane hydrochloride, 3-methylpropenyloxypropyltrimethoxydecane, 3-chloropropylmethyldimethoxydecane , 3-chloropropyltrimethoxydecane, and the like. These decane coupling agents are easily sold from the market because they are sold in Shin-Etsu Chemical Co., Ltd., etc. in the KBM series, the KBE series, and the like.

When the total amount of the liquid crystal sealing agent is 100 parts by mass, the content of the (g) decane coupling agent is preferably 0.05 to 3 parts by mass.

In the liquid crystal sealing agent of the present invention, by using (h) an inorganic filler, it is expected that the adhesion strength is improved or the moisture resistance reliability is improved. Examples of the inorganic filler include molten fused silica, crystalline cerium oxide, cerium carbide, cerium nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay. , alumina, magnesia, zirconia, aluminum hydroxide, magnesium hydroxide, calcium citrate, aluminum silicate, lithium aluminum niobate, tannic acid Zirconium, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, etc., preferably molten cerium oxide, crystalline cerium oxide, cerium nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, Talc, clay, alumina, aluminum hydroxide, calcium citrate, aluminum citrate, more preferably molten cerium oxide, crystalline cerium oxide, aluminum oxide, talc. These inorganic fillers may be used in combination of two or more. When the average particle diameter is too large, when a narrow gap liquid crystal display unit is manufactured, it is difficult to form a gap or the like when the upper and lower glass substrates are bonded together, and 3 μm or less is preferable, and preferably 2 μm or less. The particle diameter can be measured by a laser diffraction ‧ scattering particle size distribution analyzer (dry type) (manufactured by Seishin Co., Ltd.; LMS-30).

When the total amount of the liquid crystal sealing agent is 100 parts by mass, the content of the inorganic filler (h) is preferably 1 to 60 parts by mass, more preferably 1 to 40 parts by mass. When the content of the inorganic filler is too small, since the adhesion strength to the glass substrate is lowered and the moisture resistance reliability is also poor, there is a possibility that the decrease in the adhesion strength after moisture absorption is also increased. On the other hand, when the content of the inorganic filler is too large, there is a possibility that it is difficult to collapse and the gap of the liquid crystal cell cannot be formed.

In the liquid crystal sealing agent of the present invention, an additive such as a hardening accelerator, or a pigment, a leveling agent, an antifoaming agent, a solvent, or the like may be blended as needed.

Examples of the curing accelerator include an organic acid or an imidazole.

The organic acid may, for example, be an organic carboxylic acid or an organic phosphoric acid, and is preferably an organic carboxylic acid. Specific examples thereof include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid (1,2,4-benzenetricarboxylic acid), diphenylketonetetracarboxylic acid, furan dicarboxylic acid, and the like. Aromatic carboxylic acid; succinic acid (succinic acid), adipic acid, dodecanedioic acid, lipoic acid (sebacic acid), thiodipropionic acid, cyclohexanedicarboxylic acid, ginseng (2 -carboxymethyl)isocyanurate, ginseng (2-carboxyethyl)isocyanurate, ginseng (2-carboxypropyl)isocyanurate, bis(2-carboxyethyl)isocyanurate Acid esters, etc.

Further, examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, and 1- Benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethylidene 2-undecylimidazole, 2,4-diamino-6(2'-methylimidazolium(1'))ethyl-s-triazole 2,4-Diamino-6(2'-undecylimidazolium (1'))ethyl-s-triazole 2,4-Diamino-6(2'-ethyl-4-methylimidazolium(1'))ethyl-s-triazole 2,4-Diamino-6(2'-methylimidazolium(1'))ethyl-s-triazole ‧Isocyanuric acid adduct, 2:3 adduct of 2-methylimidazoisocyanuric acid, 2-phenylimidazoisocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole , 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and the like.

Regarding the liquid crystal sealing agent of the present invention, in the case where a hardening accelerator is used When the total amount of the liquid crystal sealing agent is 100 parts by mass, it is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass.

As an example of the method of obtaining the liquid crystal sealing agent of the present invention, there are the methods described below. First, the component (e) is dissolved and mixed with the component (c) as needed. Next, the component (b) is dissolved in the mixture, and the component (g) is dissolved as needed. Then, adding component (a), component (d), component (f), component (h), and defoaming agent, leveling agent, solvent, etc., as needed, to a conventional mixing device, such as a three-roll type roll The liquid crystal sealing agent of the present invention can be produced by uniformly mixing a sand mill, a ball mill or the like and filtering it with a metal mesh.

In the liquid crystal display unit of the present invention, a pair of substrates on which a specific electrode is formed on a substrate are disposed so as to face each other at a predetermined interval, and the liquid crystal sealing agent of the present invention is sealed around the liquid crystal sealing agent, and liquid crystal is sealed in the gap. The type of liquid crystal to be sealed is not particularly limited. Here, the "substrate" is composed of a substrate having at least one combination of light transmittance, such as glass, quartz, plastic, orium. In the liquid crystal sealing agent of the present invention, spacers (gap control materials) such as glass fibers are added to the liquid crystal sealing agent of the present invention, and a dispenser or a screen printing apparatus is used for one of the pair of substrates. After the liquid crystal sealing agent is applied, it is necessary to perform temporary curing at 80 to 120 ° C as needed. Then, the liquid crystal is dropped on the inside of the bank formed by the liquid crystal sealing agent, and is superposed in a vacuum. Another glass substrate is overlaid and a gap is formed. After the gap is formed, it is cured at 90 to 130 ° C for 1 to 2 hours, whereby the liquid crystal display unit of the present invention can be obtained. As described above, the liquid crystal display unit of the present invention has no display failure due to liquid crystal contamination, and is excellent in adhesion and moisture resistance reliability. Examples of the gap controlling material include glass fibers, ceria beads, and polymer beads. The diameter varies depending on the purpose, and is usually 2 to 8 μm, preferably 4 to 7 μm. The amount of use is usually 0.1 to 4 parts by mass, preferably 0.5 to 2 parts by mass, more preferably 0.9 to 1.5 parts by mass, per 100 parts by mass of the liquid crystal sealing agent of the present invention.

The liquid crystal sealing agent of the present invention has excellent resistance to liquid crystal incorporation, and the substrate bonding step in the liquid crystal dropping method does not cause liquid crystal incorporation or collapse of the sealing even in the heating step. Therefore, the manufacture of a stable liquid crystal display unit can be performed. Further, since the curable resin is crosslinked at a high speed, the constituent components are extremely small in elution of the liquid crystal, and display failure of the liquid crystal display unit can be reduced. Further, since it is excellent in handling properties and storage stability, it is suitable for the manufacture of a liquid crystal display unit. Further, the cured product is excellent in various cured properties such as adhesion strength, heat resistance, moisture resistance, and the like, and by using the liquid crystal sealing agent of the present invention, a liquid crystal display unit having excellent reliability can be produced. Further, the liquid crystal display unit manufactured by using the liquid crystal sealing agent of the present invention can sufficiently satisfy the characteristics of high voltage holding ratio and low ion density which are required as liquid crystal display units.

"Embodiment"

Hereinafter, the present invention will be described in more detail by way of Synthesis Examples and Examples, but the present invention is not limited by the examples. In addition, "parts" and "%" in this document are based on mass unless otherwise specified.

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

100 parts of commercially available benzopyranol (manufactured by Tokyo Chemical Co., Ltd.) was dissolved in 350 parts of dimethylformaldehyde. In this case, 32 parts of pyridine as a base catalyst and 150 parts of BSTFA (manufactured by Shin-Etsu Chemical Co., Ltd.) as a decylating agent were added, and the temperature was raised to 70 ° C and stirred for 2 hours. The obtained reaction liquid was cooled, and while stirring, 200 parts of water was added to precipitate the product while deactivating the unreacted decylating agent. After the precipitated product was separated by filtration, it was sufficiently washed with water. Next, the obtained product was dissolved in acetone, and recrystallized by adding water to be purified. 105.6 parts of a desired 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane (yield 88.3%) was obtained.

The analysis was carried out by HPLC (high performance liquid chromatography), and the purity was 99.0% (area percentage).

[Reference Synthesis Example 1] (Synthesis of Acrylic Epoxy Ester of Resorcinol Type Epoxy Resin)

The resorcinol diepoxypropyl ether resin was dissolved in toluene, and dibutylhydroxytoluene as a polymerization inhibitor was added thereto, and the temperature was raised to 60 °C. Then, 100% equivalent of acrylic acid of an epoxy group was added, and the temperature was raised to 80 ° C, and trimethylammonium chloride as a reaction catalyst was added thereto, and stirred at 98 ° C for about 50 hours. The obtained reaction liquid was washed with water, and toluene was distilled off, whereby an epoxy acrylate of resorcin (KAYARAD ^RTM RGE-AC100) was obtained.

[Examples 1 to 12, Comparative Examples 1 and 2] (Modulation of liquid crystal sealing agent for liquid crystal dropping method)

The resin components (component (c), component (e)) are mixed and stirred in the ratios shown in the following Tables 1 to 3, and then the radical polymerization inhibitor (component (b)) is heated and dissolved. After cooling to room temperature, an organic filler (ingredient (d)), a decane coupling agent (ingredient (g)), an inorganic filler (ingredient (h)), and a thermal radical polymerization initiator (ingredient (a) are appropriately added. ), a heat hardener (component (f)), etc., stirred, and then dispersed in a three-roll type roll mill, and then filtered through a metal mesh (635 mesh) to prepare liquid crystals of Examples 1 to 12. Drop the liquid crystal sealing agent for the working method. In the same manner, the liquid crystal sealing agents for liquid crystal dropping methods of Comparative Examples 1 and 2 were prepared using the respective components shown in Table 1.

In the following, the liquid crystal sealing for each liquid crystal dropping method is shown. The content of the evaluation project and its results.

(thermosetting test)

The liquid crystal sealing agent for each liquid crystal dropping method prepared was molded into 3 cm × 3 cm × 1 mm, and hardened at 120 ° C for 1 hour. The hardenability was evaluated by measuring the Shore A hardness of the cured product. The results are shown in Tables 1-3.

(Operational use test)

After mixing a gap-control material (PF-50S: manufactured by Nippon Electric Glass Co., Ltd.) of 5 μm in a liquid crystal sealing agent for 15 g of each liquid crystal dropping method for the preparation of the liquid crystal sealing agent, 0.15 g, The mixture was degassed by vacuum stirring at 500 rpm and revolution 1500 rpm for 5 minutes. The vacuum stirring defoaming device was manufactured by EME Co., Ltd. (EME Corporation) using a vacuum stirring defoaming mixer VMXC-360K. The gelation time was measured by placing it in an atmosphere of 23 ° C, and was evaluated according to the following criteria. The results are shown in Tables 1-3.

○: no gelation for 72 hours or more; Δ: gelation at 24 hours or more and less than 72 hours; ×: gelation after less than 24 hours from defoaming.

(liquid crystal contamination test)

Coated at the bottom of each 10 ml vial bottle After about 100 mg of the liquid crystal sealing agent for the liquid crystal dropping method, 10 times the amount of liquid crystal (MLC-6866-100: manufactured by Merck Ltd.) of the applied liquid crystal sealing agent was added thereto. After heating at 120 ° C for 1 hour, it was cooled for 30 minutes. Each of the supernatant liquids was fractionated by decantation to prepare a liquid crystal for measurement of the sample. The liquid crystal of the sample was measured using a digital ultra-high resistance meter (R8340: manufactured by Advantest Corporation) to measure the specific resistance value and sealed with no liquid crystal. The specific resistance values of the agents (blank liquid crystals) were compared. When comparing, the reduction index is calculated by the following formula and evaluated according to the following criteria. The results are shown in Tables 1-3.

Reduce the index =-Log(y/x)

x: specific resistance value of blank liquid crystal

y: specific resistance value of sample liquid crystal

○: the reduction index is less than 1.5; Δ: the reduction index is 1.5 or more and less than 2.0; ×: the reduction index is 2.0 or more.

(1) Synthesized according to Synthesis Example 1. (2) Hydroquinone (Kawaguchi Chemical Industry Co., Ltd.). (3) Methylhydroquinone (manufactured by Seiko Chemical Co., Ltd.). (4) Methoxyhydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.). (5) P-benzoquinone (manufactured by Seiko Chemical Co., Ltd.). (6) morphine (phenothiazine) (made by Kawaguchi Chemical Industry Co., Ltd.). (7) Synthesized according to Reference Synthesis Example 1. (8) DPEA-12 (ethylene oxide modified dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.). (9) KMP-598 (polyoxyethylene rubber powder, manufactured by Shin-Etsu Chemical Co., Ltd.). (10) ZEFIAC F-351S (Aike Industry Co., Ltd.). (11) Bisphenol A type epoxy resin (YD-8125, manufactured by Nippon Steel Chemicals Co., Ltd.). (12) SDH (manufactured by Otsuka Chemical Co., Ltd.). * SDH was used by a jet mill to pulverize to an average particle diameter of 1.5 μm. (13) Sila Ace S-510 (manufactured by Chisso Corporation). (14) Ceria (X-24-9163A, Shin-Etsu Chemical Co., Ltd.).

(1) Synthesized according to Synthesis Example 1. (2) 4-methoxy-1-naphthol (manufactured by Kawasaki Kasei Chemicals, Ltd.). (3) 2-hydroxynaphthoquinone (manufactured by Kawasaki Chemical Industry Co., Ltd.). (4) Naphthoquinone (made by Kawasaki Chemical Industry Co., Ltd.). (7) Synthesized according to Reference Synthesis Example 1. (8) DPEA-12 (ethylene oxide modified dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.). (9) KMP-598 (polyoxyethylene rubber powder, manufactured by Shin-Etsu Chemical Co., Ltd.). (10) ZEFIAC F-351S (Aike Industry Co., Ltd.). (11) Bisphenol A type epoxy resin (YD-8125, manufactured by Nippon Steel Chemical Co., Ltd.). (12) SDH (manufactured by Otsuka Chemical Co., Ltd.). * SDH is used by finely pulverizing into an average particle diameter of 1.5 μm by a jet mill. (13) Sila Ace S-510 (manufactured by Chisso Co., Ltd.). (14) Ceria (X-24-9163A, Shin-Etsu Chemical Co., Ltd.).

(1) Synthesized according to Synthesis Example 1. (2) POLYSTOP 7300P (manufactured by Bodo Co., Ltd.) (3) ADEKA STAB LA-81 (manufactured by Asahi Kasei Kogyo Co., Ltd.) (4) TINUVIN 123 (manufactured by BASF Corporation) (7) Synthesized according to Reference Synthesis Example 1. (8) DPEA-12 (ethylene oxide modified dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.). (9) KMP-598 (polyoxyethylene rubber powder, manufactured by Shin-Etsu Chemical Co., Ltd.). (10) ZEFIAC F-351S (Aike Industry Co., Ltd.). (11) Bisphenol A type epoxy resin (YD-8125, manufactured by Nippon Steel Chemical Co., Ltd.). (12) SDH (manufactured by Otsuka Chemical Co., Ltd.). * SDH is used by finely pulverizing into an average particle diameter of 1.5 μm by a jet mill. (13) Sila Ace S-510 (manufactured by Chisso Co., Ltd.). (14) Ceria (X-24-9163A, Shin-Etsu Chemical Co., Ltd.).

From the results of Tables 1 to 3, it was confirmed that the liquid crystal sealing agent for liquid crystal dropping method of the present invention containing a specific radical polymerization inhibitor (component (b)) and components (a), (c), and (d) is It is excellent in thermosetting property, workability, and liquid crystal contamination.

[Industrial use possibility]

The liquid crystal sealing agent for liquid crystal dropping method of the present invention has excellent heat hardenability and excellent resistance to incorporation, workability and storage stability, The cured product properties such as adhesion strength are also excellent. Therefore, the design freedom of the liquid crystal display unit can be ensured, which contributes to productivity and long-term reliability.

Claims (15)

A liquid crystal sealing agent for liquid crystal dropping method, comprising: (a) a thermal radical polymerization initiator, (b) a radical polymerization inhibitor, (c) a curable resin having a (meth) acrylonitrile group, and (d) An organic filler, and the aforementioned component (b) is a radical polymerization inhibitor represented by any one of the following formulas (1) to (3), or a radical polymerization inhibitor having a piperidine skeleton: (In the formula (1), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and R ³ represents a hydroxyl group or a C1-C4 alkyl group, wherein -OR ¹ , -OR ² , and -R ³ Either hydroxy); (In the formula (2), R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyl group or a C1-C4 alkyl group, wherein -OR ⁴ , -OR ⁵ , and -R ⁶ Either hydroxy); (In the formula (3), R ⁷ represents a hydrogen atom, a hydroxyl group, or a C1-C4 alkyl group). The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the radical polymerization inhibitor having a piperidine skeleton is a radical polymerization inhibitor represented by the following formula (4): (In the formula (4), the group A represents a hydrogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amine group, a C1-C4 alkoxy group, a phenoxy group, an ethenyl group (-NHCOCH ₃ ), a benzamidine group. (-OCOC ₆ H ₅ ), isothiocyanate group (-NCS), pendant oxy group (=O), or a group represented by any one of the following formulae (5) to (7); And a hydrogen atom, an oxygen atom, a C1-C4 alkyl group, or a C1-C20 alkoxy group; wherein, in the case of an oxygen atom, a nitroso group is represented by NO; and R ⁸ to R ¹⁵ are each independently represented by C1. -C4 alkyl); (in the formula (5), * means the bonding position); (in the formula (6), * means a bonding position, the base C means the same as the aforementioned base B, and R ¹⁶ to R ¹⁹ are each independently representing a C1-C4 alkyl group); (In the formula (7), * means a bonding position, a group D means the same as the above-mentioned group B, R ²⁰ represents a C1-C20 alkylene group, and R ²¹ to R ²⁴ each independently represent a C1-C4 alkyl group. ). The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the component (d) is rubber fine particles. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the component (d) is at least one selected from the group consisting of acrylic rubber, styrene rubber, styrene olefin rubber, and silicone rubber. Rubber particles. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 1, wherein the component (c) is a curable resin having a (meth)acryl fluorenyl group and having a resorcinol skeleton. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 1, wherein the component (c) is a curable resin containing a compound having three or more (meth) acrylonitrile groups in one molecule. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the component (a) has no oxygen-oxygen bond (-OO-) or nitrogen-nitrogen bond (-N=N- in the molecule). a thermal radical polymerization initiator. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein Further, it further comprises (e) a curable resin having an epoxy group and (f) a thermosetting agent. The liquid crystal sealing agent for liquid crystal dropping method according to claim 8, wherein the component (f) is an organic acid hydrazine. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, further comprising (g) a decane coupling agent. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, further comprising (h) an inorganic filler. The liquid crystal sealing agent for liquid crystal dropping method according to claim 8, wherein when the total amount of the component (c) and the component (e) is 100 parts by mass, the content of the component (b) is 0.0001. ~1 parts by mass. A method for producing a liquid crystal sealing agent for a liquid crystal dropping method, which is a method for producing a liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 12, which comprises dissolving the component (b) in the aforementioned component ( The steps in c). A method for producing a liquid crystal sealing agent for liquid crystal dropping method, which is a method for producing a liquid crystal sealing agent for liquid crystal dropping method according to claim 8 or 9, comprising dissolving the component (b) in the component (e) A step of. A liquid crystal display unit obtained by curing a cured product obtained by curing a liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 12, and sealing the liquid crystal display unit.