JP2001247821A - Moisture-proof coating agent composition for display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sealing agent for a display panel having improved moisture permeability, impact resistance and low strain and capable of curing at a low temperature. SOLUTION: This moisture-proof coating agent composition for display panels has a moisture permeation quantity (JIS Z-0208) at 40 deg.C of not higher than 1.0 g/m2.24 hr, a softening point (Tm) in the range of 100 deg.C and 160 deg.C or a solubility to an organic solvent at 25 deg.C of not less than 50 mass %. The composition consists of, for example, 15-55 mass % thermoplastic resin (A), 10-65 mass % wax (B), and 5-50 mass % resin (not exceeding 100 mass % as a total) for giving tackiness (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for a moisture-proof coating of a display. More specifically, the present invention relates to a moisture-proof coating composition having excellent moisture permeability and flexibility. The present invention also relates to a method for producing a display using the composition for a moisture-proof coating of the display, and a display.

[0002]

2. Description of the Related Art Liquid crystal displays and EL displays are
It is used not only for notebooks and desktops but also for mobile phones, mobile terminals, and in-car displays, and is required to be used in more severe environments than in the past. Especially at high temperature and high humidity, the liquid crystal and E
Influence of water on the L element and poor conduction due to erosion of the device terminal cause display failure. Therefore, in order to protect the panel and the terminal portion from the outside air, a moisture-proof coating layer is formed and protected. Silicone resins, epoxy resins, and the like are used as moisture-proof coating agents in display elements such as liquid crystal displays and EL displays. Among them, the silicone resin has a problem of low moisture permeability and low adhesive strength to an adherend. On the other hand, epoxy resins are widely used in this field because of their excellent adhesiveness, chemical resistance, moisture permeability, and electrical insulation properties.However, since they are hard and brittle, they cause distortion of panel members due to curing shrinkage. Reduction and further improvement of impact resistance have been desired. Further, curing at a lower temperature has been desired.

[0003]

[Problems to be Solved by the Invention] As a protective coating layer for maintaining the display quality of a liquid crystal display device or an EL display device for a long period of time, moisture resistance to shut off moisture from outside air, and shrinkage at the time of forming a coating layer on a panel. The present invention relates to a moisture-proof coating agent composition for a display panel, which is excellent in flexibility and low-temperature film-forming property so as not to cause distortion and cause display failure, and has excellent toughness and adhesion to withstand mechanical stress during use of the display.

[0004]

Means for Solving the Problems The present inventors have conducted various studies in order to solve the above-mentioned problems, and as a result, the JIS standard (Z-0)
208: Moisture permeability at 40 ° C. measured by the method specified in “208: Moisture Permeability Test Method for Moisture-Proof Packaging Material”
/ m ² · 24H or less, and the softening point temperature (Tm) is 10
By forming the moisture-proof coating layer of the display using a composition having a solubility of 50% or more at 0 ° C. to 160 ° C. or at 25 ° C. in an organic solvent, it is possible to form a film at a low temperature and to obtain a panel by shrinkage. It has been found that there is formed a moisture-proof coating agent for a display having no distortion, excellent in toughness and adhesiveness to withstand mechanical stress during use of the display, and excellent in moisture permeability to block the moisture of the outside air. The moisture-proof coating agent comprises (A) a thermoplastic resin, (B) a wax,
(C) A composition obtained by blending a tackifier resin. That is, the present invention provides the following (1) to (11). (1) Moisture permeability at 40 ° C (JIS Z-0
208) is 1.0 g / m ^{2 ·} 24H or less, and has a softening point (Tm) of 100 ° C. to 160 ° C. or a solubility in an organic solvent at 25 ° C. of 50% by mass or more. object. (2) The composition is (A) a thermoplastic resin 15
(B) 10 to 65% by weight of a wax, (C) 5 to 50% by weight of a tackifying resin (the total does not exceed 100% by weight), and the display panel according to (1). Moisture-proof coating composition. (3) The moisture-proof coating composition for a display panel according to (2), wherein the thermoplastic resin (A) is a styrene-ethylene-butene-styrene copolymer and / or a styrene-ethylene-propylene-styrene copolymer. . (4) The wax (B) has a softening point of 60 to 1
(2) The moisture-proof coating composition for display panels according to (2) or (3), wherein the composition has a temperature of 60 ° C. (5) The moisture-proof coating composition for a display panel according to (2) to (4), wherein the wax is a polypropylene wax. (6) The moisture-proof coating composition for a display panel according to (5), wherein the polypropylene wax is isotactic propylene. (7) The moisture-proof coating composition for a display panel according to (1) to (6), wherein the organic solvent has a boiling point of 200 ° C. or lower. (8) The organic solvent is an alcohol, a glycol ether, an ethylene glycol ether acetate,
The moisture-proof coating composition for a display panel according to (7), which is at least one selected from the group consisting of aromatic hydrocarbons, alicyclic hydrocarbons, ketones, esters, and ethers. (9) A method for manufacturing a display panel, wherein the moisture-proof coating agent composition for a display panel according to any one of (1) to (8) is applied to the outside of a sealing material. (10) A method for manufacturing a display panel, wherein the moisture-proof coating agent composition for a display panel according to any one of (1) to (8) is applied so as to cover the entire outer surface of the sealing material. (11) A display panel manufactured using the moisture-proof coating agent composition for a display panel according to any one of (1) to (8).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a moisture-proof coating composition for a display panel of the present invention, a display panel using the composition, and a method for producing the same will be described in detail.

[Moisture-Proof Coating Composition for Display Panels] The moisture-proof coating composition for display panels of the present invention has a water vapor transmission rate at 40 ° C. (JIS Z-020).
8) is a composition having a softening point (Tm) of 100 ° C. to 160 ° C. or a solubility in an organic solvent at 25 ° C. of 50% by mass or more at 1.0 g / m ^{2 ·} 24H or less. As the organic solvent, any organic solvent can be used as long as it can be used for improving coating properties or coating properties, and more specifically, a diluent described below can be mentioned. The composition may be any as long as it satisfies the physical properties described above, and is not particularly limited in its composition and production method, but is preferably (A) a thermoplastic resin, (B) a wax,
(C) It may contain a tackifying resin, and if necessary, other resins, additives and the like. (A) The use amount of the thermoplastic resin is preferably from 15 to 55% by mass, more preferably from 25 to 45% by mass. When the amount used is 15% by mass or more, the moisture resistance and the adhesive strength at high temperatures are further improved, and when the amount used is 55% by mass or less, the adhesiveness is further improved, and when melting or diluting the solvent. The viscosity can be reduced and workability is improved. (B) The wax is preferably from 10 to 65% by mass, more preferably from 20 to 50% by mass. When the amount used is 10% or more, the viscosity can be kept low at the time of melting or dilution with a solvent, so workability is improved, and when it is 65% by mass or less, adhesion is improved, and adhesion at high temperatures is improved. preferable. (C) The tackifying resin is preferably 5 to 50% by mass, more preferably 10 to 40% by mass. When the amount is 5% or more, the adhesion is improved, and when it is 50% by mass or less, the adhesion at high temperatures is improved, which is preferable.
The sum of (A) to (C) does not exceed 100% by mass. If necessary, the composition may contain a resin other than (A) to (C), an additive, and the like.

<(A) Thermoplastic Resin> The (A) thermoplastic resin used in the present invention can be appropriately selected so as to satisfy the above conditions. Although the physical properties are not particularly limited, the softening point of these thermoplastic resins is preferably from 120 to 165 ° C, more preferably from 125 to 145 ° C.
By setting the softening point to 120 ° C. or higher, the heat resistance can be improved, and the adhesion at high temperatures and the moisture resistance can be improved. When the softening point is 165 ° C. or lower, the viscosity can be lowered at the time of melting or at the time of dilution with a solvent, and the workability is improved. Specific examples include styrene-based resins, olefin-based polymers, polyamides, polyesters, and polyurethanes. Of these, styrene polymers are preferred. These thermoplastic resins can be used alone or in combination of two or more. Needless to say, a thermosetting resin or the like may be contained as long as the object of the present invention is not impaired.

(Styrene-based polymer) Examples of the styrene-based polymer include a styrene polymer or a copolymer of styrene and another comonomer. The copolymer may be random or block, but a block copolymer is preferred. Among them, styrene / ethylene / butene / styrene copolymer, styrene / butene / styrene copolymer, styrene /
Ethylene / propylene / styrene copolymer, styrene /
Isoprene / styrene block copolymers are more preferred. Styrene / ethylene / butene / styrene copolymer, especially when moisture permeability at high temperatures and adhesion are required
It is particularly preferable to use at least one of styrene / ethylene / propylene / styrene copolymer.

(Olefin polymer) Examples of the olefin polymer include rubber resins such as ethylene-α-olefin copolymer and propylene-α-olefin copolymer, polyethylene, polypropylene, ethylene-vinyl acetate copolymer. , Ethylene-acrylic acid (ethyl) copolymer, ethylene-methacrylic acid (methyl) copolymer, ethylene
Examples thereof include a vinyl alcohol copolymer, an ethylene / ethyl acrylate / maleic anhydride copolymer, and an olefin / maleic anhydride adduct.

<(B) Wax> As the (B) wax used in the present invention, any wax can be used as long as the physical properties of the obtained display panel composition satisfy the above range. The softening point of the wax is not particularly limited, but is preferably from 65 ° C to 160 ° C.
C. to 150.degree. C. are more preferred. Softening point temperature is 6
When the temperature is 5 ° C. or higher, the heat-resistant adhesiveness is improved. When the temperature is 160 ° C. or lower, the viscosity can be reduced at the time of melting or dilution with a solvent, and the workability is improved. Specific examples include paraffin wax, microcrystalline wax, polypropylene wax, polyethylene wax and the like. Preferably polypropylene wax,
More preferred is an isotactic polypropylene wax. These can be used alone or in combination of two or more.

<Tackifier> The (C) tackifier resin used in the present invention may be any (C) tackifier resin as long as the physical properties of the obtained display panel composition satisfy the above range. But you can use it. Specifically, for example, at least one selected from the group consisting of aliphatic petroleum resin, alicyclic petroleum resin, aromatic petroleum resin, rosin petroleum resin, terpene petroleum resin, and each hydrogenated resin is used. Is preferred.

<Other Additives> Other additives that can be used in the present invention include organic peroxides, diluents, plasticizers, fillers, and antioxidants.

(Organic peroxide) The organic peroxide of the display panel is preferably used for heat denaturation to impart heat resistance. Any organic peroxide that can impart heat resistance can be used. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5- Di (t-butylperoxy) -3-hexyne and the like can be mentioned.

(Diluent) The diluent can be used for imparting coatability or improving the coatability. As a diluent, an organic solvent is usually used. The physical properties of the organic solvent are not particularly limited, but a compound or a mixture having a boiling point of 200 ° C. or lower at 1 atm is preferable, a boiling point of 150 ° C. or lower is more preferable, and a temperature of 70 ° C. to 130 ° C. is more preferable. These diluents can be used alone or in combination of two or more, and the amount used is not particularly limited, and the amount is selected according to the suitability for application.

These include alcohols, glycol ethers, ethylene glycol ether acetates, aromatic hydrocarbons, ketones, esters, ethers and the like. Specific examples of these compounds include the following.

As alcohols, for example, methanol,
Ethanol, propanol, butanol and the like can be mentioned.

Examples of glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether,
3-methoxybutanol, 3-methyl-3-methoxybutanol and the like.

Examples of the ethylene glycol ether acetates include ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, and ethyl ethoxyprote Piolate and the like. Examples of the aromatic hydrocarbon include toluene, xylene and the like. Ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone and the like.

Esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, 2-hydroxy-2-
Methyl methyl propionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate,
Ethyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, propyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, methoxyacetic acid Ethyl, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate,
Butyl ethoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, 2-ethoxypropion Propyl acetate, butyl 2-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate,
Propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3
-Ethyl ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate and the like.

Examples of the ethers include tetrahydrofuran.

(Plasticizer) A plasticizer is preferably added for imparting or improving flexibility. Any plasticizer can be used as long as the moisture-proof coating composition for a display panel satisfies the above physical properties and can impart and improve flexibility, and there is no particular limitation. Specifically, for example,
Examples thereof include liquid polybutene, low molecular weight polyisobutylene having a molecular weight of 5,000 to 12,000, paraffinic oil, naphthenic oil, process oil, and linear aliphatic acid esters.

(Filler) The filler is preferably added to keep the heat shrinkage in an appropriate range. Further, the extender may be used as long as the effect of the present invention is not impaired.
Any filler can be used as long as the moisture-proof coating composition for a display panel satisfies the above-mentioned physical properties and can further reduce the heat shrinkage within a predetermined range, and there is no particular limitation. Specific examples include silica, alumina, barium sulfate, calcium carbonate, titanium oxide, carbon black, and talc.

(Antioxidant) An antioxidant is preferably added to prevent thermal deterioration. Any antioxidant can be used as long as the moisture-proof coating composition for a display panel satisfies the above physical properties and can further prevent thermal deterioration, and there is no particular limitation. Specifically, for example, a hindered phenol compound, a phosphate compound and the like can be mentioned.

[Production Method of Display Panel] The production of the composition for a protective coat of the present invention comprises (A) a thermoplastic resin,
The wax (B) and the tackifying resin (C) may be mixed under a nitrogen atmosphere by a powerful stirring and mixing device such as a sigma blade type kneader, and there is no particular limitation. Generally, 1 to 3 at a temperature in the range of 120 to 200 ° C.
Perform in time. After uniform mixing, the mixture is cooled to obtain a solid resin. The composition for a protective coat of the present invention is applied by the following method. The coating method is not particularly limited, but the following two types are usually known. (1) The composition for a protective coat of the present invention is applied to an arbitrary position using a hand gun and a hot melt applicator. After cooling, a moisture-proof coating layer is obtained. (2) The protective coating composition of the present invention is dissolved in an optional diluting solvent and adjusted to a predetermined viscosity. Apply to the location using a precision applicator such as a dispenser. 50-80 ° C
To obtain a moisture-proof coating layer.

The obtained moisture-proof coating film has excellent moisture permeability and excellent properties of flexibility, toughness, and adhesion. When used as a moisture-proof coating film for a display panel, it can be used under high temperature and high humidity conditions. However, the present invention provides a composition capable of maintaining the display quality.

[0026]

The present invention will be described below in more detail with reference to Examples and Comparative Examples.

(Evaluation method) Table 1 shows the results of evaluation by the following test methods. 1 Moisture Permeability Test A moisture-proof coating film adjusted to a thickness of 100 μm using the adjusted moisture-proof coating composition was subjected to a temperature of 40 ° C. and a humidity of 9 in accordance with JIS Z-0208 (Moisture-proof packaging material moisture permeability test method).
The moisture permeability was measured under the conditions of 0%, a temperature of 60 ° C, and a humidity of 90%. 2 Softening point measurement test JIS-K-22 using the adjusted moisture-proof coating composition
07, according to the ring and ball method. 3 Toluene solubility test The toluene solubility at 25 ° C was measured using the adjusted moisture-proof coating composition. 4 Adhesion Test Glass (JIS) using the adjusted moisture-proof coating composition
R3202) was measured for shear strength. 5 Workability test The workability when a moisture-proof coating film was prepared by the method described in the method of use (1) above using the adjusted moisture-proof coating composition was evaluated in three stages. ○ Good workability △ Bad workability × Notably poor workability 6 Moistureproof coating film formation test on panel to evaluate flexibility and cure shrinkage 11.3 inch liquid crystal display device,
A moisture-proof coating film was formed using the moisture-proof coating composition prepared in four pieces. 3 distortions and cracks in the panel after coating film formation
It was evaluated on a scale. ○ No abnormality in appearance △ Distortion of panel × Cracking of panel 7 High-temperature and high-humidity test Display state of liquid crystal panel with moisture-proof coating layer created in 3 and environment of 60 ° C and 95% The display state of the panel after being left for 500 hours was observed, and evaluated in the following three stages. ○ Good with no change from the initial state △ Display failure partially occurred × Display failure occurred entirely

[Raw materials] <Thermoplastic resin> (A-1) Clayton G-1657 (manufactured by Shell Chemical) (A-2) Septon 2043 (manufactured by Kuraray) (A-3) JSR EP01P (manufactured by JSR) (A- 4) Toughmer HL-0809 (manufactured by Mitsui Chemicals) <wax> (B-1) Viscol 660P (manufactured by Sanyo Chemical) (B-2) Ethylene content 5% by weight MI value 30, melting point 1
50 ° C <Tackifier> (C-1) Escolets 5300 (manufactured by Tonex) (C-2) Escolets 4401 (manufactured by Tonex) <Plasticizer> Plasticizer-1 Nisseki Polybutene HV-100 (manufactured by Nippon Oil) Organic peroxide> Organic peroxide-1 Dicumyl peroxide <Antioxidant> Antioxidant-1 Irganox 1010 (manufactured by Ciba Specialty Chemicals) <Epoxy resin> (Epoxy resin-1) Epicoat 828 (oilification) Made of shell)
/ M-xylylenediamine = 85/15 (epoxy resin-2) EP4000 (manufactured by Asahi Denka) /m-xylylenediamine=86.5/13.5 <silicone resin> (silicone resin-1) SE9175 (Toray Co., Ltd.) Dow Corning Silicone)

Example 1 30% by mass of a styrene / ethylene / 1-butene / styrene copolymer, 20% by mass of propylene wax, 35% by mass of a hydrogenated aliphatic petroleum resin, and 15% by mass of polybutene were placed in a nitrogen atmosphere. After kneading for 1 hour with a melt kneader, the composition was cooled and adjusted to obtain a moisture-proof coating composition. Moisture permeability test using the adjusted moisture-proof coating composition,
Table 1 shows the results of an adhesion test, a moisture-proof coating film formation test on the panel, and a high-temperature and high-humidity test of the panel in order to evaluate flexibility and curing shrinkage.

(Example 2-6) The moisture-proof coating film was evaluated according to Example 1 except that the composition shown in Table 1 was used. Table 1 shows the results.

[0031]

[Table 1]

(Comparative Example 1-5) The compositions shown in Table 2 were evaluated in comparison with Examples. Table 2 shows the results.

[0033]

[Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 191/06 C09D 191/06 G02F 1/1333 500 G02F 1/1333 500 // C09D 153/00 C09D 153 / 00 F-term (reference) 2H090 HB07X HC05 HD15 LA03 4J038 CB021 CB022 CB031 CB032 CB041 CB042 CB051 CB052 CB061 CB071 CB072 CB081 CB082 CB091 CB091 CC031 CC032 JAQ07 CR07 JA02 PC03

Claims (11)

[Claims] 1. An amount of moisture permeation at 40 ° C. (JIS
Z-0208) is 1.0 g / m ^{2 ·} 24H or less, and the softening point temperature (Tm) is 100 ° C. to 160 ° C. or the solubility in an organic solvent at 25 ° C. is 50% by mass or more. A moisture-proof coating agent composition for a display panel. 2. The composition comprises: (A) 15 to 55% by mass of a thermoplastic resin, (B) 10 to 65% by mass of a wax, (C) 5 to 50% by mass of a tackifying resin, wherein the total is 100%. The moisture-proof coating composition for a display panel according to claim 1, wherein the composition does not exceed 10% by mass. 3. The method according to claim 1, wherein the thermoplastic resin (A) is styrene.
The moisture-proof coating agent composition for a display panel according to claim 2, which is an ethylene-butene-styrene copolymer and / or a styrene-ethylene-propylene-styrene copolymer. 4. The softening point temperature of the wax (B) is 6
4. The moisture-proof coating composition for a display panel according to claim 2, wherein the temperature is 0 to 160.degree. 5. The moisture-proof coating composition for a display panel according to claim 2, wherein the wax is a polypropylene wax. 6. The method according to claim 5, wherein said polypropylene wax is isotactic propylene.
A moisture-proof coating composition for a display panel according to the above. 7. The moisture-proof coating composition for a display panel according to claim 1, wherein the organic solvent has a boiling point of 200 ° C. or lower. 8. The organic solvent is selected from the group consisting of alcohols, glycol ethers, ethylene glycol ether acetates, aromatic hydrocarbons, alicyclic hydrocarbons, ketones, esters, and ethers. The moisture-proof coating composition for a display panel according to claim 7, wherein the composition is at least one kind. 9. A method for manufacturing a display panel, comprising applying the moisture-proof coating agent composition for a display panel according to claim 1 to an outside of a sealing material. 10. An electrode and a driver IC using the moisture-proof coating agent composition for a display panel according to claim 1.
A method for manufacturing a display panel, wherein the method is applied so as to cover the entire surface. 11. A display panel manufactured using the moisture-proof coating agent composition for a display panel according to claim 1.