JP2866322B2 - Liquid crystal cell assembly sealing material composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing material composition for assembling a liquid crystal cell.

[0002]

2. Description of the Related Art Conventionally, a large number of liquid crystal cells using glass as a substrate have been occupied. In recent years, a film liquid crystal having an engineering plastic as a substrate has been developed. Advantages of the film liquid crystal are that it is thinner, does not break, is lighter than glass liquid crystal, and can be used for curved surface display. Regardless of whether the substrate is made of glass or engineering plastic, the properties required for the sealing material for liquid crystal cells are that they are in direct contact with the liquid crystal molecules and do not adversely affect the liquid crystal molecules. It has excellent moisture resistance from the surface, has strong adhesiveness that can withstand expansion and contraction due to temperature change of the liquid crystal cell and various stresses applied from the outside, and keeps the liquid crystal cell gap constant For this reason, there is no filler having a diameter larger than the diameter of the spacer.

[0003] As described above, the sealing material has very many properties, but unlike a sealing material for a glass liquid crystal cell, which may exhibit rigid physical properties when cured, a sealing material for a film liquid crystal cell is not used. In order to follow the flexibility of the film, the cured sealing material must have appropriate flexibility. In order to pursue flexibility, the number of sealing materials having excellent moisture resistance when the resin is three-dimensionally crosslinked is extremely small. Japanese Unexamined Patent Publication No. 6-90379 discloses an epoxy resin containing an alkylene oxide-containing epoxy as a main component. In this system, flexibility can be realized, but moisture resistance is poor. As described above, in the prior art, a sealing material for a film liquid crystal which compensates for these disadvantages has not yet been developed.

[0004]

SUMMARY OF THE INVENTION The present invention provides a flexible and moisture resistant film which follows the flexibility of a film,
An object of the present invention is to provide a sealing material composition for a film liquid crystal cell having excellent liquid crystal resistance, electric resistance and orientation resistance.

[0005]

The inventor of the present invention has made extensive studies to solve the above-mentioned problems, and as a result, has completed the present invention. That is, the present invention relates to a sealing material composition for assembling a liquid crystal cell comprising an epoxy resin, an epoxy resin curing agent and other components, wherein (a) a bifunctional silicone which is liquid at room temperature as an epoxy resin component. 10 to 50 parts by weight of a modified epoxy resin (hereinafter abbreviated as silicone-modified epoxy), (b) 90 to 50 parts by weight of a bisphenol-type epoxy resin (hereinafter abbreviated as bis-type epoxy) liquid at room temperature, and as an epoxy resin curing agent, (C)
20 to 80 parts by weight of a trifunctional thiol compound which is liquid at room temperature, 0.5 to 5.0 parts by weight of (d) a silane coupling agent, and (e) an average particle diameter of 1 μm or less as other components. 1 to 10 parts by weight of regular silica, and (f) 5 to 5 parts of inorganic filler other than amorphous silica having an average particle size of 2 μm or less.
A sealing material composition for assembling a liquid crystal cell, comprising 0 parts by weight as an essential component.

The silicone-modified epoxy used in the present invention is represented by the general formula (1).

[0007]

Embedded image (Wherein, R ₁ : — (CH ₂ ) ₃ —R ₂ , R ₃ , R ₄ , R ₅ : a methyl group or a phenyl group n: an integer of 1 ≦ n ≦ 9)

The amount of the silicone-modified epoxy used is 10 to 50 parts by weight, preferably 10 to 30 parts by weight, and more preferably 10 to 20 parts by weight, based on 100 parts by weight of the total epoxy resin component. When the amount of the silicone-modified epoxy used is 10 parts by weight or less, the physical properties of the cured sealing material become hard and rigid, and the ability to follow the deformation of the film is undesirably reduced. On the other hand, when the amount is more than 50 parts by weight, the curing reaction is remarkably slowed down, and the water absorption of the cured product is undesirably increased. Only by combining a silicone-modified epoxy with a bis-epoxy resin that is liquid at room temperature, it is possible to obtain a sealing material composition that combines appropriate reactivity and flexibility suitable for practical use and has excellent moisture resistance. Particularly, it is useful as a sealing material for film liquid crystal.

Next, the room temperature liquid trifunctional thiol curing agent used in the present invention has, for example, a structure represented by the following general formula (2).

[0010]

Embedded image (Wherein, R: ester group or carbonyl group)

The silane coupling agent used in the present invention is not particularly limited. For example, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethylaminopropylmethyldimethoxy Examples thereof include silane and γ-mercaptopropyltrimethoxysilane. The amount of the silane is 0.5 to 5 parts by weight, preferably 0.5 to 1.0 part by weight, per 100 parts by weight of the epoxy resin. By adding these silane coupling agents, the adhesiveness to the film substrate is remarkably improved, and the penetration of external moisture into the liquid crystal cell can be inhibited.

Next, examples of the inorganic filler used in the present invention include titanium oxide, spherical silica, alumina, calcium carbonate, amorphous silica, and the like. Essential conditions for maintaining a uniform cell gap of the liquid crystal are as follows. Is that the maximum particle size is smaller than that of the spacer. The average particle diameter of titanium oxide, spherical silica, alumina, calcium carbonate, etc. is 2 μm or less, and the average particle diameter of amorphous silica is 1 μm or less. The use of amorphous silica having an average particle size of 1 μm or less is for imparting thixotropy to the entire system. If a certain thixotropy is not provided, the printability is adversely affected, and a precise seal pattern cannot be formed. In addition, it is desirable to use those inorganic fillers that have been conditioned for 3 months or more in an atmosphere at a temperature of 60 to 70 ° C. and a humidity of 2 to 5%. If this pretreatment is not performed, the moisture content in the sealing material composition will undergo seasonal variations. The sealing material produced using the inorganic filler not subjected to the above-mentioned humidity control treatment has a seasonal variation in viscosity and thixotropy, which disturbs the linearity of the seal pattern at the time of pre-baking in a line, and causes bleeding and the like. May cause. Further, there are cases where various adverse effects such as a foaming phenomenon of the sealing material when the films are superposed and fully cured are caused.

The amount of the amorphous silica used is as follows:
The amount is 1 to 10 parts by weight with respect to 00 parts by weight, but if the amount is less than 1 part by weight, the thixotropy is reduced, and the seal pattern formed by screen printing or dispenser is shaped when passing through a heating step. May cause disturbance. On the other hand, if the amount is more than 10 parts by weight, the fluidity of the entire sealing material system is deteriorated, and the separation of the plate during screen printing is adversely affected, which is not preferable.

The amount of the inorganic filler other than amorphous silica is 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin. However, the fluidity is extremely increased at the time of heating such as pre-baking, which is not preferable because the shape is disturbed. When used in an amount of more than 50 parts by weight, the viscosity is remarkably increased, adversely affecting workability in forming a seal pattern such as screen printing, and increasing the elastic modulus of the cured sealing material. It is not preferable because the property cannot be obtained.

The sealing material composition for assembling a film liquid crystal cell of the present invention is usually cured using a curing accelerator. The type and amount of the curing accelerator that can be used are not particularly limited, and examples thereof include trisdimethylaminomethylphenol (TAP), salts of TAP and octylic acid, imidazoles, and triphenylphosphine (TPP). . The amount used is 0.1 with respect to 100 parts by weight of the epoxy resin.
The amount is preferably from 0.1 to 3 parts by weight. When the amount is less than 0.1 part by weight, the effect promoting effect cannot be sufficiently exhibited, which is not preferable. On the other hand, when the amount is more than 8 parts by weight, the pot life is shortened, and the workability is adversely affected, which is not preferable.

[0016]

The present invention will be described in more detail with reference to the following examples. (Example 1) 20 g of a silicone-modified epoxy represented by the formula (1) (BY16-855, manufactured by Dow Corning Toray Silicone Co., Ltd., epoxy equivalent: 650), bisphenol A type epoxy (Epicoat 828, Yuka Shell Epoxy Co., Ltd.) ), An epoxy equivalent of 190) was stirred with a DC motor, and amorphous silica (R-9) having an average particle size of 0.5 μm was stirred.
72, manufactured by Nippon Aerosil Co., Ltd.) were dispersed uniformly. Furthermore, γ-glycidoxypropyltrimethoxysilane (Sila Ace S-510, manufactured by Chisso Corporation) 1
g, 80 g of titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) having an average particle size of 1 μm was added and uniformly mixed, followed by further kneading with a three-roll mill to obtain a base material. Further, a trifunctional thiol having an isocyanurate skeleton represented by the formula (2) (TH
EIC-BMPA, manufactured by Yodo Chemical Co., Ltd., mercapto equivalent 17
4) To 79 g, octylate of trisdimethylaminomethylphenol (K-61B, Anchor Chemical Co., Ltd.)
1.0 g, amorphous silica having an average particle size of 0.5 μm (R-
972, manufactured by Nippon Aerosil Co., Ltd.) 5 g, average particle size 1 μm
Of titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) and uniformly mixed with a DC motor were further kneaded with a three-roll mill to obtain a curing agent. These base materials / hardening agents were mixed at a ratio of 100/56 and stirred well to obtain a sealing material for assembling a liquid crystal cell. Take this sealing material into an aluminum container,
Heated at 150 ° C for 2 hours to make a 5cm thick cured product,
The hardness was measured to be 50 for Shore A. A cured product was prepared by replacing the silicone-modified epoxy component of this composition with PEG epoxy (Epolite 400E, manufactured by Kyoeisha Chemical Co., Ltd.). And 85 ° C / 85% / 24hr
When subjected to high temperature and high humidity treatment and compared the water absorption of both,
5% water absorption, PE using silicone-modified epoxy
The use of G epoxy showed a water absorption of 10%, and the use of silicone-modified epoxy showed a water absorption of 1/2.

(Example 2) Silicone-modified epoxy (B
20 g of Y16-855B, manufactured by Dow Corning Toray Silicone Co., Ltd., epoxy equivalent 2200), and bisphenol F type epoxy (EXA835LV, Dainippon Ink)
Co., Ltd., epoxy equivalent 165) 50 g and bisphenol A type epoxy (AER-2500, manufactured by Asahi Ciba Co., Ltd.)
30 g of an epoxy equivalent (185) was added, and the mixture was stirred with a DC motor, and 5 g of amorphous silica (R-972, manufactured by Nippon Aerosil Co., Ltd.) having an average particle size of 0.5 μm was dispersed so as to be uniform. Further, γ-aminopropyltriethoxysilane (S-
330, manufactured by Chisso Corp.) 1 g, α having an average particle size of 1 μm or less
-Alumina (AKP-3000, manufactured by Sumitomo Chemical Co., Ltd.) 80
g was added and the mixture was uniformly mixed and further kneaded with a three-roll mill to obtain a main ingredient. Further, a trifunctional thiol having a isocyanurate skeleton represented by the formula (2) (THEIC-BMP
A, Yodo Chemical Co., Ltd., mercapto equivalent 174) 83 g,
0.5 g of trisdimethylaminomethylphenol (TAP, manufactured by Kayaku Akzo Co., Ltd.), 5 g of amorphous silica (R-972, manufactured by Nippon Aerosil Co., Ltd.) having an average particle size of 0.5 μm, and an average particle size of 1 μm or less 15 g of α-alumina (AKP-3000, manufactured by Sumitomo Chemical Co., Ltd.) was added, and a mixture obtained by uniformly mixing with a DC motor was further kneaded with a three-roll mill to obtain a curing agent.
These base materials / hardening agents were mixed at a ratio of 100/56 and stirred well to obtain a sealing material for assembling a liquid crystal cell. The sealing material was placed in an aluminum container and heated at 150 ° C. for 2 hours to form a cured product having a thickness of 5 cm.
Was 60. A cured product was prepared by replacing the silicone-modified epoxy component of this composition with PEG epoxy (Epolite 400E, manufactured by Kyoeisha Chemical Co., Ltd.). And 8
When a high-temperature and high-humidity treatment of 5 ° C./85%/24 hr was performed and the water absorption of both was compared, the water absorption of silicone-modified epoxy was 3%, and the water absorption of PEG epoxy was 10%. .

[0018]

[Comparative example]

(Comparative Example 1) 5 g of a silicone-modified epoxy represented by the formula (1) (BY16-855, manufactured by Dow Corning Toray Silicone Co., Ltd., epoxy equivalent: 650), bisphenol F type epoxy (Epicoat 807, Yuka Shell Epoxy Co., Ltd.) ), An epoxy equivalent of 170) was stirred with a DC motor, and amorphous silica (R-97) having an average particle size of 0.5 μm was stirred.
2, manufactured by Nippon Aerosil Co., Ltd.) was uniformly dispersed. Further, 1 g of γ-glycidoxypropyltrimethoxysilane (Sila Ace S-510, manufactured by Chisso Corporation),
Titanium oxide with an average particle size of 1 μm (CR-EL, Ishihara Sangyo
A mixture obtained by adding 80 g (manufactured by Co., Ltd.) and mixing uniformly was further kneaded with a three-roll mill to obtain a base material. Further, a trifunctional thiol having an isocyanurate skeleton represented by the formula (2) (THE
IC-BMPA, manufactured by Yodo Chemical Co., Ltd., mercapto equivalent 17
4) To 99 g, octylate of trisdimethylaminomethylphenol (K-61B, Anchor Chemical Co., Ltd.)
1.0 g, amorphous silica having an average particle size of 0.5 μm (R-
972, manufactured by Nippon Aerosil Co., Ltd.) 5 g, average particle size 1 μm
Of titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) and uniformly mixed with a DC motor were further kneaded with a three-roll mill to obtain a curing agent. These base materials / hardeners were mixed at a ratio of 100/67 and stirred well to obtain a sealant for assembling a liquid crystal cell. Take this sealing material into an aluminum container,
Heated at 150 ° C for 2 hours to make a 5cm thick cured product,
When the hardness was measured, the Shore D was 40, and the result was inferior in flexibility to those of Examples 1 and 2.

[0019]

As described above, the cured sealing material has both flexibility and moisture resistance, and a sealing material composition particularly useful for a film liquid crystal cell can be obtained.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI G02F 1/1339 505 G02F 1/1339 505 // (C08K 13/02 3:36 5:54) (58) Fields surveyed (Int. .Cl. ⁶ , DB name) C08L 63/00-63/10 C08G 59/20-59/30 C08G 59/66 G02F 1/3339 505 C08K 3/36 C08K 5/54 C09K 3/10

Claims (3)

(57) [Claims] In a sealing material composition for assembling a liquid crystal cell comprising an epoxy resin, an epoxy resin curing agent and other components, the epoxy resin component comprises (a) a bifunctional silicone which is liquid at room temperature. 1 modified epoxy resin
0 to 50 parts by weight, (b) 90 to 50 parts by weight of a bisphenol type epoxy resin liquid at room temperature, and (c) two trifunctional thiol compounds at room temperature as liquid epoxy resin curing agent.
0 to 80 parts by weight, and as other components, (d) 0.5 to 5.0 parts by weight of a silane coupling agent, (e) 1 to 10 parts by weight of amorphous silica having an average particle diameter of 1 μm or less,
(F) A sealing material composition for assembling a liquid crystal cell, comprising 5 to 50 parts by weight of an inorganic filler other than amorphous silica having an average particle size of 2 μm or less as an essential component. 2. The silicone-modified epoxy of the general formula (1)
The sealing material composition for assembling a liquid crystal cell according to claim 1, wherein Embedded image (Wherein, R ₁ : — (CH ₂ ) ₃ —R ₂ , R ₃ , R ₄ , R ₅ : a methyl group or a phenyl group n: an integer of 1 ≦ n ≦ 9) 3. The sealing material composition for assembling a liquid crystal cell according to claim 1, wherein the trifunctional thiol compound is represented by the general formula (2). Embedded image (Wherein, R: ester group or carbonyl group)