JP2005222037A - Sealing agent composition for liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing agent composition for a liquid crystal display element, the agent which can suppress production of voids caused by local hardening and heat generation during a thermosetting process after UV curing by using a finely granulated latent hardening agent, and which has excellent adhesion property and shape holding property. <P>SOLUTION: The sealing agent composition for a liquid crystal display element contains: (A) a mixture containing a partially (meth)acrylate-modified epoxy compound obtained by allowing (meth)acrylic acid to react with epoxy resin; (B) epoxy resin; (C) a latent hardening agent having 0.1 to 2 μm average particle diameter and ≤4 μm cumulative particle diameter at 90 mass%; (D) a photoinitiator; and (E) an inorganic filler. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sealing agent composition for a liquid crystal display element that performs two-stage curing of ultraviolet (UV) curing and heat curing, and in particular, a liquid crystal display that suppresses generation of voids due to volatile components during heat curing after UV curing. The present invention relates to an element sealing agent composition.

  Conventionally, a manufacturing method of a liquid crystal display element has been applied in a state in which a sealant is applied to a TFT side substrate by screen printing or a dispenser device, and then a color filter side substrate sprayed with a bead-like spacer agent is overlaid. Under pressure, the sealing agent is heated and cured to produce an empty panel. Further, since this liquid crystal display element is manufactured by cutting the empty panel with a scribe device and then injecting liquid crystal through the injection port under reduced pressure, it takes time to inject liquid crystal. In addition, there is a technical problem that the proportion of the liquid crystal injection time increases by increasing the substrate size and reducing the panel gap in order to reduce the response speed of the liquid crystal, resulting in a decrease in productivity and liquid crystal display. It was difficult to reduce the cost of the apparatus.

  However, in recent years, there has been a strong demand for cost reduction of large panels, and a method for manufacturing a liquid crystal display device using an ODF (One Drop Fill) method has been studied. In the conventional method, since the liquid crystal that has not been brought into contact with the uncured sealant composition has come into contact, the contamination of the sealant composition with respect to the liquid crystal has emerged as an important problem. The ODF method is a color filter side substrate or photospacer in which a sealing agent is applied to the TFT side substrate by screen printing or a dispenser device, then liquid crystal is applied by the dispenser device, and a beaded spacer agent is dispersed. This is a method in which the color filter side substrates on which are formed are bonded together.

A conventional ODF type sealant uses a (meth) acrylate-modified epoxy resin as an ultraviolet curing component, a liquid epoxy resin as a thermosetting component, and an amine compound as a latent curing agent. However, with an increase in the size of the glass substrate, there is an increasing demand for strength (adhesive force) after ultraviolet curing, and the ultraviolet curing ratio is high. For this reason, an increase in the photodecomposition component has occurred due to an increase in the photoinitiator component. In addition, a coupling agent or the like is usually added for the purpose of increasing the adhesive strength to the base material, and alcohol components are generated by hydrolysis thereof. Furthermore, there is a strong demand for improvement in pot life for the sealing agent, and the curability of the latent curing agent which is a thermosetting component cannot be improved so much. For the above reasons, there is a problem of generation of voids due to volatile components during thermosetting.
In addition, the following is mentioned as a prior art relevant to this invention.

Japanese Patent Laid-Open No. 10-273644 JP 2000-347203 A JP 2001-133794 A

  The present invention has been made in consideration of the above-described circumstances, and has little contamination with liquid crystal, which is required for conventional sealing agent compositions for liquid crystal display elements, and voids due to volatile components during heat-curing. It aims at providing the sealing compound composition for liquid crystal display elements which does not generate | occur | produce.

  As a result of intensive studies to solve the above problems, the present inventors have found that a component having a large particle size in the latent curing agent is strongly related as a cause of voids generated at the time of thermal curing after UV curing. In this case, preferably, the latent curing agent is finely pulverized by a wet bead mill, whereby it is found that a sealing agent composition for a liquid crystal display element that does not generate voids at the time of thermal curing can be obtained. It came.

Therefore, the present invention
(A) a mixture containing a partially (meth) acrylate-modified epoxy compound obtained by reacting an epoxy resin with (meth) acrylic acid,
(B) epoxy resin,
(C) a latent curing agent having an average particle size of 0.1 to 2 μm and a particle size of 90 μ% when accumulated to 4 μm or less,
(D) a photopolymerization initiator,
(E) A sealant composition for a liquid crystal display device comprising an inorganic filler is provided.

As a more preferred embodiment, part or all of the latent curing agent is represented by the following general formula (1).
R ¹ C ₃ H ₆ SiR ² _n (OR ³ ) _3-n (1)
(In the formula, R ¹ is a glycidoxy group, an acryloxy group or a methacryloxy group. R ² and R ³ are alkyl groups, and n is 0, 1 or 2.)
The above-mentioned sealant composition for liquid crystal display elements is provided, which is mixed with a silane coupling agent represented by the formula (1) and treated with a wet bead mill.

を示し、「アクリロキシ基」はＣＨ₂＝ＣＨＣＯＯ−（アクリロイロキシ基）を、「メタクリロキシ基」はＣＨ₂＝Ｃ（ＣＨ₃）ＣＯＯ−（メタクリロイロキシ基）を示す。 In the present invention, (meth) acrylic acid is acrylic acid or methacrylic acid, (meth) acrylate is acrylate or methacrylate, (meth) acryloyl group is acryloyl group or methacryloyl group, and (meth) acryloxy group is acryloxy group. Or a methacryloxy group is shown.
In addition, “glycidoxy group”

“Acryloxy group” represents CH ₂ ═CHCOO— (acryloyloxy group), and “methacryloxy group” represents CH ₂ ═C (CH ₃ ) COO— (methacryloyloxy group).

  According to the present invention, by using a pulverized latent curing agent, generation of voids due to local curing heat generation at the time of thermal curing after UV curing can be suppressed, and liquid crystal having excellent adhesion and shape retention. A sealant composition for display elements can be provided.

The sealant composition for liquid crystal display elements of the present invention is
(A) a mixture containing a partially (meth) acrylate-modified epoxy compound obtained by reacting an epoxy resin with (meth) acrylic acid,
(B) epoxy resin,
(C) a latent curing agent having an average particle size of 0.1 to 2 μm and a particle size of 90 μ% when accumulated to 4 μm or less,
(D) a photopolymerization initiator,
(E) An inorganic filler is an essential component.

[(A) Partial (meth) acrylate-modified epoxy compound-containing reaction mixture]
The component (A) used in the sealant composition for a liquid crystal display device of the present invention is a reaction mixture obtained by reacting an epoxy resin with (meth) acrylic acid, and this comprises two or more epoxy groups per molecule. And (meth) acrylic acid with an equivalent ratio of epoxy group / (meth) acryloyl group = 9/1 to 1/9, more preferably epoxy group / (meth) acryloyl group = 6/4 to 3/7 are preferred.

  The present invention uses a reaction product obtained by reacting (meth) acrylic acid with an epoxy resin. The reaction product of this epoxy resin and (meth) acrylic acid is a bisphenol type epoxy resin such as bisphenol A type epoxy resin or bisphenol F type epoxy resin having two or more epoxy groups in one molecule, phenol novolac type It can be obtained by the reaction of epoxy resin such as epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin and (meth) acrylic acid. it can. Among these, those obtained by reacting a bisphenol type epoxy resin and (meth) acrylic acid are preferable.

  As a reaction ratio of such an epoxy resin and (meth) acrylic acid, the molar ratio of (meth) acryloyl group of (meth) acrylic acid and epoxy group of epoxy resin ([(meth) acryloyl group / epoxy group] × 100) = 10 to 100% of the reaction is preferable, and more preferably 30 to 70% of the reaction is used. If the proportion of (meth) acrylic acid is too large, it may take time for the water washing process to remove excess (meth) acrylic acid after the reaction, which may make purification difficult. Since the content of (meth) acryloyl groups in the product is reduced, the adhesive force during photocuring is weakened, and the temporary fixing effect is also deteriorated, the glass substrate may be peeled off.

  The above reaction is usually preferably carried out in an organic solvent such as toluene. Further, it is preferable to use an addition reaction catalyst such as triphenylphosphine, triethylamine, triethanolamine or the like. These blending amounts are not particularly limited. Moreover, although the said reaction can be performed according to a conventional method, as reaction conditions, it is preferable to set it as 3 to 24 hours at 80-110 degreeC.

By the above reaction, a part (meth) acrylate-modified epoxy compound in which a part of the epoxy group of the epoxy resin is modified to a group represented by the following general formula (1), and all the epoxy groups of the epoxy resin are represented by the following general formula The (meth) acrylate modified compound modified to the group represented by (1) is produced, and these are usually the unreacted epoxy resin, the partial (meth) acrylate modified epoxy compound, and the (meth) acrylate modified. Present as a mixture with the compound.

と表した場合、これを（メタ）アクリル酸
ＣＨ₂＝ＣＲ−ＣＯＯＨ（ＲはＨ又はＣＨ₃）
と反応させると、未反応のエポキシ樹脂（ｉ）と、

で示されるエポキシ樹脂の一部のエポキシ基が開環した部分（メタ）アクリレート変性エポキシ化合物（ｉｉ）と、

で示されるエポキシ樹脂の全部のエポキシ基が開環した（メタ）アクリレート変性化合物（ｉｉｉ）が得られる。
従って、上記式（１）の基は、

として存在する。 That is, for example, epoxy resin

And (meth) acrylic acid CH ₂ = CR-COOH (R is H or CH ₃ )
When reacted with unreacted epoxy resin (i),

A partial (meth) acrylate-modified epoxy compound (ii) in which a part of the epoxy group of the epoxy resin represented by

A (meth) acrylate-modified compound (iii) in which all the epoxy groups of the epoxy resin represented by the above formula are opened is obtained.
Therefore, the group of the above formula (1) is

Exists as.

  Unreacted epoxy resin present in the above reaction mixture, partially (meth) acrylate-modified epoxy compound in which a part of the epoxy group of the epoxy resin is modified, and all of the epoxy groups of the epoxy resin are modified (meth) As a mixing ratio of the acrylate-modified compound, the unreacted epoxy resin is 0 to 80% by mass, particularly 5 to 45% by mass, the partial (meth) acrylate-modified epoxy compound is 5 to 60% by mass, particularly 35 to 55% by mass, It is preferable that the (meth) acrylate-modified compound is mixed in an amount of 0 to 90% by mass, particularly 10 to 55% by mass.

  Moreover, since the partial (meth) acrylate-modified epoxy compound of the component (A) of the present invention has a large compatibility and dilution effect with the epoxy resin of the component (B) described later, the sealing agent composition for liquid crystal display elements of the present invention. There is no problem with the adjustment workability.

[(B) Epoxy resin]
As an epoxy resin used with the sealing compound composition for liquid crystal display elements of this invention, what has two or more epoxy groups per molecule and can use all conventionally well-known things. Specific examples thereof include, for example, bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, glycidylamine. Type epoxy resin, alicyclic epoxy resin, dicyclopentadiene type epoxy resin, triphenolmethane type epoxy resin, triphenolethane type epoxy resin and the like. These can be used singly or in combination of two or more.

  Among these, bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin have relatively low viscosity and are heat resistant. It is preferable because of its excellent moisture resistance.

  The epoxy resin contains epichlorohydrin in the synthesis process, and therefore contains a small amount of chlorine derived from this epichlorohydrin. The total chlorine content is preferably 1,500 ppm or less, more preferably 1,000 ppm or less. Moreover, it is preferable that the chlorine concentration in water after adding 10 times mass ion-exchange water to an epoxy resin and performing an extraction process on the conditions of 100 degreeC x 20 hours is 10 ppm or less.

  The amount of this epoxy resin is the sum of the unreacted epoxy resin in component (A) and the epoxy resin in component (B), and the total epoxy groups are usually equivalent to (meth) acrylic equivalents. The ratio (epoxy group / (meth) acryloyl group, molar ratio) is 0.7 to 1.2, preferably 0.8 to 1.1. If the amount of the epoxy resin is too large, the curing in the sealant composition may be insufficient even when curing by ultraviolet irradiation, and the adhesive strength to the glass substrate may be insufficient. If it is too high, the curability by ultraviolet irradiation will be good, but the properties of the cured product after the final heat curing may be deteriorated.

  In this case, it is usually preferable to blend the component (B) at a ratio of 5 to 30 parts by weight, particularly 10 to 15 parts by weight, with respect to 100 parts by weight of the component (A).

[(C) Latent curing agent]
The latent curing agent used in the sealant composition for liquid crystal display elements of the present invention is solid at room temperature, and liquefies during heat curing to act as a curing agent for the epoxy resin.
Examples of this component include dicyandiamide, Amicure PN-23, Amicure PN-H, Amicure PN-31, Amicure PN-D, Amicure MY-24, Amicure MY-H, Amicure MY-D (trade names: Amicure, Ajinomoto) Amine adduct compounds such as carbohydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, iminodiacetic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide , Dodecanediohydrazide, hexadecanedihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrate Dorazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4'-bisbenzenedihydrazide, 1,4-naphthoic acid dihydrazide, Amicure VDH, Amicure UDH (trade name: Amicure, Ajinomoto Co., Ltd.), Quen And organic acid hydrazides such as acid trihydrazide. These can be used alone or in combination of two or more. Among these, Amicure VDH and Amicure UDH represented by the following formula can be preferably used because they have a relatively low melting point and an excellent balance of curability.

Amicure VDH
(1,3-bis (hydrazinocarbonoethyl) -5-isopropylhydantoin)

Amicure UDH
(7,11-octadecadien-1,18-dicarbohydrazide)

The latent curing agent has an average particle size of 0.1 to 2 [mu] m, preferably 0.5 to 1.5 [mu] m, and a particle size of 90 [mu]% accumulated is 4 [mu] m or less, particularly 3.5 [mu] m or less. Is used. Here, the average particle diameter is a cumulative weight average value D ₅₀ (or median diameter) measured by a particle size distribution measuring device (Microtrac MT3000: manufactured by Nikkiso Co., Ltd.) based on the laser diffraction scattering method. . Moreover, the particle size at the time of 90 mass% accumulation is also a measured value by the particle size distribution measuring apparatus by a laser diffraction method.

  Here, since the latent curing agent is a solid at room temperature, in the use thereof, a wet pulverized and classified by a device such as a bead mill, an attritor or a ball mill is used as a pretreatment, and further three It is preferable to disperse and knead with a roll or the like so that the average particle size becomes 90% by mass when accumulated, and more preferably no maximum particle size is 3 μm or more.

In this case, it is preferable to use a product obtained by mixing a part or all of the latent curing agent with a silane coupling agent represented by the following general formula (1) and treating the mixture with a wet bead mill.
R ¹ C ₃ H ₆ SiR ² _n (OR ³ ) _3-n (1)
(In the formula, R ¹ is a glycidoxy group, an acryloxy group or a methacryloxy group. R ² and R ³ are alkyl groups, and n is 0, 1 or 2.)

Here, the alkyl group of R ² preferably has 1 or 2 carbon atoms, and the alkyl group of R ³ preferably has 1 or 2 carbon atoms.

  Examples of the silane coupling agent used for surface treatment of the latent curing agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropyltriethoxy. Silane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ- Examples include acryloxypropyltriethoxysilane. These can be used singly or in combination of two or more. Among these, γ-glycidoxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like can be preferably used from the viewpoint of further improving the potential.

  When using the said silane coupling agent, the usage-amount is about 0.1-10 mass parts normally with respect to 100 mass parts of latent hardening | curing agents, and should be added especially in the range of 1-5 mass parts. Is preferred. If the amount added is too small, the surface treatment may not be sufficiently performed and the pot life may be deteriorated. On the other hand, if the amount is too large, the liquid crystal may be contaminated.

  In addition, although it does not specifically limit about the apparatus used when surface-treating a latent hardening | curing agent with a silane coupling agent, A Henschel mixer, a ball mill, a bead mill etc. are mentioned, Even if it processes by any method of dry or wet Good.

The wet bead mill is not particularly limited as long as it has a rotor for creating a shearing field in a container for treating a slurry solution containing a curing agent and beads moving in the shearing field. Continuously equipped with a pump mechanism capable of repeatedly processing a slurry containing a curing agent, and a separator mechanism that prevents beads from flowing out when the resin is discharged. A system type is preferable. As such a bead mill, SC-MILL (SC100) manufactured by Mitsui Mining Co., Ltd. can be used. The beads to be used are not limited, but those made of zirconia, alumina, glass, steel with a diameter of 0.25 to 1.5 mm can be used according to the material and fraction of the curing agent, and the processing chamber is effective. It is preferable to fill 60 to 90% by volume of the volume, more preferably 80 to 85% by volume. In the case of a continuous wet bead mill equipped with a separator mechanism, a rotational viscometer of a slurry containing a curing agent is adjusted by adjusting the processing temperature, the blending amount of the curing agent, and the processing flow rate in order to perform repeated processing smoothly. It is necessary to make the viscosity (25 ° C.) measured by the method below 50 Pa · s or less.
These latent curing agents are preferably subjected to a surface treatment with a silane coupling agent or the like in order to improve storage stability.

  The blending amount of the latent curing agent is usually 18 to 26 parts by mass, preferably 20 to 24 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). preferable. If the amount is too large, unreacted curing agent remains, which may affect moisture resistance. On the other hand, if the amount is too small, unreacted / uncured epoxy resin remains, which may cause deterioration of cured product characteristics.

[(D) Photopolymerization initiator]
As the photopolymerization initiator used in the sealant composition for a liquid crystal display element of the present invention, all conventionally known photopolymerization initiators used for photopolymerization of (meth) acryloyl groups can be used.

Specific examples of the photopolymerization initiator component include, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 1-phenyl-2-hydroxy-2. -Methylpropan-1-one, benzophenone, 1- {4- (2-hydroxyethoxy) -phenyl} -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- {4- (Methylthio) phenyl} -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, oligo (2-hydroxy-2-methyl-1) Phenyl ketones such as-(4- (1-methylvinyl) phenyl) propanone (manufactured by ESACURE KIP-150 LAMBERTI SpA), (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, (2,4,6-trimethylbenzoyl) diphenyl Examples thereof include benzoylphosphine oxides such as phosphine oxide, etc. These can be used alone or in combination of two or more.
Among the above examples, ESACURE KIP-150 (same as above) and the like are preferable particularly for liquid crystal display elements from the viewpoint of low VOC (volatile organic compound) during photocuring.

  The photopolymerization initiator component is preferably added in an amount of 1 to 6 parts by mass, particularly 2 to 4 parts by mass, per 100 parts by mass of the component (A). If the addition amount is too small, the photopolymerizability / curability may be lowered, and conversely if it is too much, the preservability of the sealing agent composition tends to be lowered. Furthermore, problems such as voids due to decomposition components of the photoinitiator are likely to occur.

[(E) Inorganic filler]
In order to reduce the expansion coefficient, various conventionally known inorganic fillers can be added to the sealing agent composition for liquid crystal display elements of the present invention.

  Examples of the inorganic filler include fused silica, crystalline silica, alumina, titanium oxide, silica titania, boron nitride, aluminum nitride, silicon nitride, magnesia, magnesium silicate, talc, mica, and the like. However, two or more types can be used in combination. Of these, silica, alumina and talc are preferably used alone or in combination of two or more.

  The inorganic filler used preferably has a particle size of 3 μm or more and a content of 1% by mass or less and an average particle size of 0.5 to 2 μm. Here, when the particle size exceeding 3 μm exceeds 1% by mass, the gap-out accuracy of the glass substrate is deteriorated, and the bonding may be difficult. On the other hand, when the average particle size is less than 0.5 μm, the viscosity increases, the coating amount from the needle decreases, the coating speed decreases, and the productivity may deteriorate. The average particle diameter is a value measured by a particle size distribution measuring apparatus based on the laser diffraction scattering method.

  The content of the inorganic filler in the sealant composition for a liquid crystal display element of the present invention is 10 to 30% by mass, preferably 15 to 25% by mass. When the content is less than 10% by mass, since the expansion coefficient is large, there is a tendency to cause distortion after curing. When it exceeds 30% by mass, the viscosity of the composition becomes high, so that the dispersibility of the spacer agent to be added after use and the gap-out accuracy of the glass substrate may be deteriorated.

  It is preferable to use the inorganic filler that has been surface-treated with a coupling agent such as a silane coupling agent or a titanium coupling agent in advance. More preferably, the epoxy resin to be used and the filler surface-treated with a coupling agent are preliminarily decompressed and kneaded. Thereby, the interface between the filler surface and the epoxy resin can be well wetted, and the moisture resistance reliability is remarkably improved.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, γ- Methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β (aminoethyl) ) Γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-amino Propyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane, etc. Silane coupling agents, titanium coupling agents, aluminum coupling agents, and the like. These can be used singly or in combination of two or more. Among these, it is preferable to use a silane coupling agent, and it is possible to obtain a sealant composition for a liquid crystal display element that is excellent in moisture resistance reliability and has a small decrease in adhesive strength after moisture absorption deterioration.
When using the said coupling agent, the usage-amount is about 0.5-2.0 mass parts with respect to 100 mass parts of said inorganic fillers.

[Other ingredients]
The liquid crystal display element sealant composition of the present invention may be blended with a thermoplastic resin such as silicone powder, silicone rubber, silicone oil, liquid polybutadiene rubber, or acrylic core shell resin for the purpose of reducing stress.
Furthermore, a silane coupling agent, a polymerization inhibitor, an antifoaming agent, a leveling agent, an ion trap agent, and other additives can be blended as necessary.

<Silane coupling agent>
Various known silane coupling agents can be added to the sealing agent composition of the present invention in order to improve the familiarity of the composition.

  Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, γ- Methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β (aminoethyl) ) Γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-amino Propyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane, etc. Is mentioned. These can be used singly or in combination of two or more. Among these, it is preferable to use γ-glycidoxypropyltrimethoxysilane, and it is possible to obtain a sealant composition for a liquid crystal display element which has excellent moisture resistance reliability and little decrease in adhesive strength after moisture absorption deterioration.

  When using the said coupling agent, the usage-amount is 0.1-5.0 mass parts normally with respect to 100 mass parts of said (A)-(E) component, Preferably 0.3-3. 0 parts by mass.

[Preparation of sealant composition for liquid crystal display element]
The sealant composition for a liquid crystal display element of the present invention can be obtained by stirring, mixing and dispersing the above components simultaneously or separately while applying heat treatment as necessary. The apparatus used for stirring, mixing, and dispersing these mixtures is not particularly limited, and a raikai machine, a three roll, a ball mill, a planetary mixer, and the like equipped with a stirring and heating device can be used. You may combine these apparatuses suitably.

[Application of sealant composition for liquid crystal display element]
When the sealing agent composition of the present invention is used as a sealing agent for a liquid crystal display element, its application method is not particularly limited. For example, it can be applied to the production of a liquid crystal panel by the following method. Into the liquid crystal display element sealant composition of the present invention, 1% by mass of silica fiber (short fiber having a diameter of 5 μm) is blended as a spacer, and dispersed and defoamed with a vacuum stirring defoaming device. Sort. Next, using a dispenser device, after drawing a pattern with a line width of 0.2 mm and a height of 0.05 mm on a glass substrate, a predetermined amount of liquid crystal (MLC-6628, manufactured by Merck) Apply spot. Next, this glass substrate is placed under reduced pressure (13.3 Pa), and the glass substrates are overlaid. Thereafter, the load is set to 0.1 kgf / cm ² , UV irradiation is performed (illuminance 100 mW / cm ² , light amount 2.5 J / cm ² ) and temporary fixing (temporary curing) is performed, and then the glass substrate is mounted. Return to atmospheric pressure. Next, a liquid crystal panel is manufactured by performing heat curing of the sealant and reorientation of the liquid crystal under conditions of 120 ° C. × 1 hour in a hot press.
The obtained liquid crystal panel can be attached with a polarizing film and a backlight, displayed in a flashing manner, checked for the presence or absence of alignment unevenness around the sealant, and evaluated for reliability, thereby confirming that there is no problem.

  EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example. In the following examples, parts and% mean mass parts and mass%, respectively. Moreover, the number in Table 2 and Table 3 means a mass part. The treatment of the curing agent used in Examples 1 to 6 and Comparative Examples 1 to 4 was performed by the following method.

[Preparation Example 1]
As a latent curing agent, a hydrazide compound shown in Table 1 as a curing agent D: Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.) is used, dispersed in toluene in which VDH is difficult to dissolve, and a slurry solution having a concentration of 10% by mass. Was prepared. The mixture was kneaded with a wet bead mill to obtain a finely pulverized slurry solution. The wet bead mill is a wet bead mill (rotor rotation speed 3,200 rpm, temperature 25 ° C., flow rate 500 cm ³ / min, separator spacing 0.1 mm, filled with zirconia beads having a diameter of 0.3 mm in a processing chamber (volume 600 cm ³ ). , Mitsui Mining Co., Ltd., SC100), 10 minutes as one step, repeated 5 or 10 times. A portion of the treated slurry solution was sampled, the particle size distribution (MT3000, manufactured by Nikkiso Co., Ltd .: Microtrac) was measured, and the rest was stripped by spray drying or an evaporator, and then a vacuum dryer set at 60 ° C. Then, deaeration was performed at 2 mmHg for 24 hours, and the solvent was removed to obtain curing agents A (5 times treated product) and B (10 times treated product) shown in Table 1.

[Preparation Example 2]
For 100 parts by mass of Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.), which is a latent curing agent, 2 parts by mass of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent is dissolved and dispersed in toluene. A 10% by weight slurry solution was prepared. Thereafter, the same treatment as in Condition A of Preparation Example 1 was performed to obtain VDH (curing agents C and D) treated with a silane coupling agent and pulverized.

[Preparation Example 3]
Curing agent E was obtained by using Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.), which is a latent curing agent, in an untreated state.

[Preparation Example 4]
Curing agent F was VDH-J (trade name, manufactured by Ajinomoto Co., Inc.) obtained by pulverizing Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.), which is a latent curing agent, with a jet mill pulverizer.

[Preparation Example 5]
As a latent curing agent, Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.) was used and dispersed in toluene in which VDH is difficult to dissolve to prepare a slurry solution having a concentration of 30% by mass. A finely pulverized slurry solution was obtained by kneading with a wet batch attritor. The wet batch attritor was treated for 6 hours with a wet attritor (rotor rotation speed 100 rpm, temperature 25 ° C.) filled with 50% by volume of zirconia beads having a diameter of 5 mm in a tank (volume 5 liters) to prepare a slurry solution. Thereafter, the same treatment as in Preparation Example 1 was performed to obtain finely pulverized VDH (curing agent G).
The results of the particle size distribution of the above curing agents A to G are shown in Table 1.

[Synthesis Example 1]
Synthesis of reaction product (a) of epoxy resin and methacrylic acid (1) A 1 L round bottom flask equipped with a stirrer, a cooling tube and a thermometer was added to a bisphenol A type epoxy resin (trade name: RE-310S, Nippon Kayaku Co., Ltd.) 184 g, 43.1 g of methacrylic acid, 1 g of triphenylphosphine, 0.13 g of BHT (dibutylhydroxytoluene), and 100 g of toluene were dissolved and the raw materials were dissolved while stirring, and then reacted at a temperature of 100 ° C. for 6 hours. It was. After completion of the reaction, the unreacted methacrylic acid was neutralized and removed with a saturated aqueous sodium hydrogen carbonate solution, and then washed with ion-exchanged water for purification. The ionic conductivity of the aqueous solution after washing was measured with an electric conductivity meter (CM-30V, manufactured by Toa DKK Corporation) and confirmed to be 0.25 mS / m. The reaction solution after purification was azeotropically dehydrated while bubbling air and concentrated at 70 ° C. under reduced pressure to completely remove and purify toluene to obtain a reaction product (a) of an epoxy resin and methacrylic acid.

GPC and IR of the reaction product obtained here were measured. The results are shown in FIGS. From GPC (FIG. 1), 13% by mass of unreacted bisphenol A type epoxy resin represented by the following formula, 45% by mass of methacrylated bisphenol A type epoxy resin (partial methacrylate modified epoxy compound) represented by the following formula, 42 It was a mixture of completely methacrylated bisphenol A resin (methacrylate-modified compound) whose mass% was represented by the following formula. IR (NEAT) (FIG. 2) is the secondary produced by the opening of the α, β-unsaturated ester acid-derived peak, 1725 cm ⁻¹ (C═O), 1195 cm ⁻¹ (C—O) and the epoxy ring. A peak derived from a hydroxyl group, 3500 cm ⁻¹ (OH) was shown.

[Examples 1 to 6]
As the component (A), the reaction mixture obtained in Synthesis Example 1 was used. As the component (B), bisphenol A type epoxy resin: RE-310S (trade name, manufactured by Nippon Kayaku Co., Ltd.), (C) As the latent curing agent of the component, a hydrazide compound: Amicure VDH (trade name, manufactured by Ajinomoto Co., Inc.) was used for bead mill pulverization (described in Table 1), and ESACURE KIP-150 was used as the photopolymerization initiator of component (D). (Trade name, manufactured by LAMBERTI S.P.A.), fused spherical silica, silane coupling agent: KBM-403 (trade name, γ-glycidoxypropyltrimethoxysilane) as the inorganic filler of component (E) , Manufactured by Shin-Etsu Chemical Co., Ltd.), blended in the compositions and amounts (parts by mass) shown in Tables 2 and 3, uniformly kneaded with a planetary mixer, and then solidified with three rolls The mixture was sufficiently mixed and dispersed until the material became 3 μm or less, and the obtained mixture was subjected to vacuum defoaming treatment to obtain the sealing agent compositions for liquid crystal display elements of Examples 1 to 6 of the present invention.

[Comparative Example 1]
(C) Except having changed the latent hardener of the component into the unground product (hardener E), each component was blended in the composition and amount (parts by mass) shown in Tables 2 and 3, Examples 1 to 6 In the same manner, a composition was obtained.

[Comparative Example 2]
(C) Except having changed the latent curing agent of the component into a jet mill pulverized product (curing agent F), each component was blended in the compositions and amounts (parts by mass) shown in Tables 2 and 3, and Examples 1 to In the same manner as in 6, a composition was obtained.

[Comparative Example 3]
(C) Except having changed the latent hardener of the component into the attritor pulverized product (hardener G), each component was blended in the composition and amount (part by mass) shown in Tables 2 and 3, and Examples 1 to 6 In the same manner, a composition was obtained.

[Evaluation method]
About each sealing compound composition for liquid crystal display elements obtained above, the following various tests were done, various characteristics were evaluated, and the result was shown in Tables 4 and 5. The curing conditions for each composition were first photopolymerization curing by UV irradiation (UV irradiation light amount: 2.5 J / cm ² , UV illuminance: 100 mW / cm ² ), and then heat curing (120 ° C. × 1 hour). It was.

(A) Viscosity (composition)
About each composition, according to JISZ-8803, measurement temperature: 25 degreeC, the value after 2 minutes was measured using the E-type viscosity meter.
(B) Thixo ratio (composition)
In the measurement of the viscosity in the above (a), the value of the viscosity ratio of both was measured such that the ratio of low shear to high shear was 10 times.
(C) Storage stability (composition)
After 100 parts of each composition was placed in a brown polyethylene container and sealed, the initial 25 ° C., E-type viscosity value was taken as 100, based on the rate of change in viscosity value after −20 ° C. × 30 days, as follows: Evaluated.
A: Change rate with respect to initial viscosity is less than 5%, and storage stability is very good B: Change rate with respect to initial viscosity is 5% or more and less than 10%, and storage stability is good Δ: Change rate with respect to initial viscosity Is 10 to 40%, and there is a slight problem in storage stability. X: The rate of change with respect to the initial viscosity exceeds 40%, and the storage stability is poor. (D) Pot life (composition)
Each agent composition hermetically stored in a brown polyethylene container was taken out of the freezer (−20 ° C.) and thawed for 3 hours to adjust the composition temperature to 25 ° C. The pot life (pot life) was evaluated as follows based on the viscosity change rate after standing for 48 hours at 25 ° C. and the E-type viscosity value at that time.
○: Change rate with respect to initial viscosity is less than 20%, pot life is good and sufficient Δ: Change rate with respect to initial viscosity is 20 to 40%, and there is some problem in pot life ×: Change with respect to initial viscosity The rate is over 40% and the pot life is short and insufficient

(E) Void inspection (cured product)
Into 100 parts of the sealant composition for liquid crystal display elements obtained in each of the above-mentioned examples and comparative examples, a silica fiber (short fiber having a diameter of 5 μm) as a spacer is blended in an amount of 1% by mass, and a vacuum stirring deaerator Then, the mixture was dispersed and degassed and dispensed into a syringe.
Next, draw a wire with a width of 0.3 mm and a length of 5 cm on a clean glass substrate (Corning Corp. # 1737, size 70 mm square, thickness 0.7 mm), and bond the glass substrate of the same size under reduced pressure. Then, a load was applied so that the thickness was 5 μm. After returning to normal pressure, UV irradiation was performed (illuminance 100 mW / cm ² , light amount 2.5 J / cm ² ), and then thermosetting was performed at 120 ° C. for 1 hour. The sealing agent surface of the obtained glass substrate was magnified 20 times with an actual microscope, the presence or absence of voids was measured, and evaluated as follows.
○: No generation of voids was observed in the sealant. Δ: 1 to 5 voids were observed in the sealant. ×: 6 or more voids were observed in the sealant. (F) Adhesion Test (cured product)
Next, a sealing agent composition for a liquid crystal display element in which the spacer agent is dispersed is applied to the central part of a clean glass substrate (manufactured by Corning: # 1737, size 20 mm square, thickness 0.7 mm). A glass substrate of the same size was superimposed on the substrate, and a load was applied so that the thickness was 5 μm and the diameter was 3 mm. Thereafter, UV irradiation was performed (illuminance: 100 mW / cm ² , light amount: 2.5 J / cm ² ), and then thermosetting was performed at 120 ° C. for 1 hour. A support base material was pasted on the obtained glass surface to prepare a test piece for adhesion. The obtained specimen was measured for vertical peel strength (MPa) per unit area at a pulling speed of 5 mm / min using an autograph apparatus manufactured by Shimadzu Corporation.

3 is a GPC analysis result of the reaction product of Synthesis Example 1. It is IR analysis result of the reaction product of Synthesis Example 1.

Claims (5)

(A) a mixture containing a partially (meth) acrylate-modified epoxy compound obtained by reacting an epoxy resin with (meth) acrylic acid,
(B) epoxy resin,
(C) a latent curing agent having an average particle size of 0.1 to 2 μm and a particle size of 90 μ% when accumulated to 4 μm or less,
(D) a photopolymerization initiator,
(E) A sealant composition for a liquid crystal display device, which contains an inorganic filler.   The total epoxy group amount of the epoxy group of the epoxy resin in the component (A) and the epoxy group of the epoxy resin of the component (B) is 0.7 to 1. with respect to the amount of the (meth) acryloyl group in the component (A). The sealing agent composition for a liquid crystal display element according to claim 1, wherein the composition is 2 (molar ratio: total amount of epoxy groups / total amount of (meth) acryloyl groups).   (A) Component is 0 to 80% by mass of unreacted epoxy resin, 5 to 60% by mass of (meth) acrylate-modified epoxy compound in which part of epoxy group of epoxy resin is modified, all of epoxy groups of epoxy resin The sealing agent composition for liquid crystal display elements of Claim 1 or 2 which consists of 0-90 mass% of the (meth) acrylate modified compound in which is modified.   The component (A) is an unreacted epoxy resin in an amount of 5 to 45% by mass, a portion in which a part of the epoxy group of the epoxy resin is modified (meth) acrylate-modified epoxy compound in an amount of 35 to 55% by mass, and all of the epoxy groups in the epoxy resin. The sealing agent composition for liquid crystal display elements of Claim 3 which consists of 10-55 mass% of (meth) acrylate modified compounds in which is modified. Part or all of the latent curing agent of component (C) is represented by the following general formula (1)
R ¹ C ₃ H ₆ SiR ² _n (OR ³ ) _3-n (1)
(In the formula, R ¹ is a glycidoxy group, an acryloxy group or a methacryloxy group. R ² and R ³ are alkyl groups, and n is 0, 1 or 2.)
5. The sealant composition for a liquid crystal display element according to claim 1, wherein the mixture is treated with a wet bead mill.

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