Epoxy resin composition with high refractive index and high adhesiveness and sealing material comprising same

Abstract

The present invention relates to a high-refractive-index and high-adhesiveness epoxy resin composition and a sealing material comprising the same, and more particularly, to a plurality of methods for filling and curing a crack by spraying a low-viscosity liquid using an ink jet or dispensing coating method, the composition having excellent light extraction efficiency during curing, having high adhesive strength and low outgassing properties, and having high refractive index and high adhesiveness, and a sealing material comprising the same. The high-refraction and high-adhesion epoxy resin composition and the sealing material containing the same can be used for bonding and molding organic or inorganic light-emitting display screen glass components.

Description

Technical Field

[0001] The present invention relates to a high refractive index and high adhesiveness epoxy resin composition and a sealing material containing the same, and relates to various methods that can fill gaps and cure them by spraying a low-viscosity liquid through an inkjet or dispensing coating method, etc. When cured, the light extraction efficiency is excellent, it has a high adhesive force and low outgassing property, and it can bond and mold organic or inorganic light-emitting display screen glass components. The high refractive index and high adhesiveness epoxy resin composition and the sealing material containing the same. Background Art

[0002] As the demands of users such as the high integration, thinness, lightness, shortness of displays have changed, the physical and chemical properties and usage methods of sealing materials have also changed accordingly. In the past, cathode ray tubes containing electron beams and fluorescent substances, field emission displays using emitter arrays to emit light, plasma display panels using the photoelectric effect of plasma gas, liquid crystal displays using the electrical arrangement and movement of liquid crystals, etc. have been widely used in the industry. However, due to problems such as the weight of the display itself, the display quality of dynamic images, heat generation, image retention phenomenon, and high power consumption, their performance and lifespan vary greatly. In order to improve the various disadvantages of such displays, organic light-emitting display devices have been developed since the late 1980s. Compared with traditional displays, organic light-emitting displays are lighter in weight, have better readability, contrast, and have more excellent power efficiency and response speed. However, it has been found that such display devices still have the disadvantages of image retention phenomenon and being easily affected by external temperature and humidity changes.

[0003] In the past, in order to solve such disadvantages, a method of restricting and sealing organic light-emitting display elements in a large-weight glass or transparent inorganic cavity has been used, but this may cause significant trouble to the usability, operation reliability, and thinning of subsequent products. Liquid is the most effective in terms of allowing users to freely adjust the shape of the display. In order to solve the problems faced in the past, the present invention has developed a material that is beneficial for developing display elements with excellent light extraction efficiency, high adhesive force, and low outgassing property. Summary of the Invention

[0004] Technical Problem

[0005] The technical problem that the present invention aims to achieve is to provide a high refractive index and high adhesiveness epoxy resin composition and a sealing material containing the same. The above high refractive index and high adhesiveness epoxy resin composition can use various methods such as inkjet or dispensing coating methods to fill gaps and cure them by spraying a low-viscosity liquid. During the curing process, gas generation is at a low level, the light extraction efficiency is excellent when cured, it has a high adhesive force and low outgassing property, and it can bond and mold organic or inorganic light-emitting display screen glass components.

[0006] Means for Solving the Problems

[0007] The high refractive index and high adhesiveness epoxy resin composition of the present invention for achieving the above object is characterized by comprising: (a) a high refractive index epoxy resin represented by the following Chemical Formula 1; (b) a highly reliable diluent epoxy resin containing an alicyclic group having 10 to 100 carbon atoms, which may be substituted or unsubstituted; and (c) a non-yellowing adhesive epoxy resin represented by the following Chemical Formula 2.

[0008] [Chemical Formula 1]

[0009]

[0010] [Chemical Formula 2]

[0011]

[0012] In the above Chemical Formula 1, the ring represented by the dashed line is a group fused to the adjacent 6-membered ring structure and is one of a substituted or unsubstituted C6-C60 monocyclic aryl group, a substituted or unsubstituted C6-C60 polycyclic aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 monocyclic heteroaryl group, and a substituted or unsubstituted C6-C60 polycyclic heteroaryl group. m and n are each independently an integer from 0 to 4, but they are not both 0.

[0013] In the above Chemical Formula 2, G is an organic group containing a glycidyl group, X 1 and X 2 are each independently hydrogen or methyl, p is an integer from 1 to 10, and R is a substituted or unsubstituted C10-C100 alkylene or alkenylene group.

[0014] The above high refractive index and high adhesiveness epoxy resin composition may contain 50 to 80 parts by weight of the high refractive index epoxy resin, 5 to 30 parts by weight of the non-yellowing adhesive epoxy resin, and 10 to 50 parts by weight of the highly reliable diluent epoxy resin.

[0015] The above highly reliable diluent epoxy resin can be produced by containing one or more compounds selected from the group consisting of dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, 2,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, dicyclopentadiene dioxide, and bis(3,4-epoxycyclohexylmethyl) adipate. More preferably, it can be produced by containing one or more compounds selected from the group consisting of the following A-1 to A-3.

[0016]

[0017] The above-mentioned high-refractive-index and high-adhesion epoxy resin composition may further contain 0.5 to 5.0 parts by weight of a thermal curing agent, and the thermal curing agent may be a latent thermal curing agent.

[0018] The above-mentioned high-reliability diluted epoxy resin may have a liquid refractive index of 1.56 or more and a film refractive index of 1.60 or more.

[0019] The sealing material for display elements of another invention for achieving the above object may contain the above-mentioned high-refractive-index and high-adhesion epoxy resin composition.

[0020] Advantages of the Invention

[0021] According to the present invention, since it has excellent processability, electrical, mechanical, and chemical properties possessed by conventional liquid epoxy materials, and also has excellent optical characteristics, the user of the composition can obtain operability, productivity, and reliability when using this material. Detailed Embodiments

[0022] Hereinafter, the epoxy resin composition of the present invention will be described in more detail.

[0023] Epoxy resin is a representative thermosetting resin that forms a three-dimensional network structure from a linear structure through a curing process. Due to its excellent physical properties such as heat resistance, corrosion resistance, adhesion, and insulation, it occupies a very important industrial position in the use of electrical and electronic materials. The main reasons why such epoxy resin can be used in the field of electrical and electronic materials are as follows: i) There are a wide variety of epoxy resins and their curing agents, which can provide various required physical properties; ii) The inherent physical properties of the resin such as excellent adhesion, mechanical properties, and chemical resistance are excellent; iii) Compared with other thermosetting resins, less shrinkage deformation occurs during the curing reaction; iv) When appropriately formulated into a single-component product or when using a suitable curing agent when made into a two-component product, the shelf life is long and no by-products are generated during the curing reaction; iv) It can be subjected to transfer molding, coating, casting, manual coating, etc. and can be formed into complex shapes, so it is suitable for encapsulation of electrical components.

[0024] In addition, in the present invention, by containing the following high-refractive-index epoxy resin, high-reliability diluted epoxy resin, and non-yellowing adhesive epoxy resin, a high-refractive-index and high-adhesion epoxy resin composition is obtained that maintains the inherent mechanical, chemical, and thermal properties of epoxy resin, has excellent light extraction efficiency during curing, and has high adhesion and low outgassing properties.

[0025] (a) High-refractive-index epoxy resin

[0026] The high refractive index epoxy resin of the present invention is formed by including a monomer represented by the following Chemical Formula 1.

[0027] [Chemical Formula 1]

[0028]

[0029] In the above Chemical Formula 1, the ring represented by the dotted line, as a group fused with the adjacent 6-membered ring structure, is one of a substituted or unsubstituted C6 - C60 monocyclic aryl group, a substituted or unsubstituted C6 - C60 polycyclic aryl group, a substituted or unsubstituted C6 - C60 aryloxy group, a substituted or unsubstituted monocyclic heteroaryl group with 6 - C60 carbon atoms, and a substituted or unsubstituted polycyclic heteroaryl group with 6 - C60 carbon atoms.

[0030] In the above, m and n are each independently an integer from 0 to 4, but not both 0 at the same time.

[0031] (b) High-reliability diluted epoxy resin

[0032] The high-reliability diluent epoxy resin of the present invention can be an epoxy resin manufactured from a compound containing a substituted or unsubstituted alkylene or alkenylene group with 5 to 100 carbon atoms, or a compound containing an alicyclic group. Preferably, it can be an epoxy resin manufactured from a compound containing an alicyclic group.

[0033] The above compound containing an alicyclic group can be selected from the group consisting of dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, 2,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, dicyclopentadiene dioxide, and bis(3,4-epoxycyclohexylmethyl) adipate.

[0034] More preferably, the above compound containing an alicyclic group can be a compound selected from the group consisting of the following A-1 to A-3.

[0035]

[0036] The content of the above diluent epoxy resin is preferably 10 to 50 parts by weight. Within this content range, it is beneficial for adjusting viscosity and ensuring heat resistance.

[0037] (c) Non-yellowing adhesive epoxy resin

[0038] The non-yellowing adhesive epoxy resin of the present invention is a bifunctional epoxy resin represented by the following Chemical Formula 2, which can be used to promote the curing structure of the epoxy resin composition, relieve the stress between the substrates of the display, and enhance the adhesion between the chip and the substrate.

[0039] [Chemical Formula 2]

[0040]

[0041] In the above Chemical Formula 2, G is an organic group containing a glycidyl group, and X 1 and X 2 are each independently hydrogen or methyl, n is an integer from 1 to 10, and R is a substituted or unsubstituted C10-C100 alkylene or alkenylene group.

[0042] As the difunctional epoxy resin represented by the above Chemical Formula 2, a diglycidyl ether-based difunctional epoxy resin is preferred. Specifically, at least one selected from the group consisting of bisphenol F diglycidyl ether type epoxy resin, bisphenol A diglycidyl ether type epoxy resin, polyolefin-added bisphenol A diglycidyl ether type epoxy resin, polyolefin-added bisphenol F diglycidyl ether type epoxy resin, 1,6-hexanediol diglycidyl ether type epoxy resin, and 1,4-butanediol diglycidyl ether type epoxy resin can be used.

[0043] In the present invention, the content of the above non-yellowing adhesive epoxy resin is preferably 5 to 30 parts by weight. If the content of the above non-yellowing adhesive epoxy resin is less than 5 parts by weight, the usable time of the product at room temperature is shortened, and the high-temperature and high-humidity reliability may not reach the desired effect. In addition, the inherent hardness of the composition is excessively increased and it is easily broken, which also has an adverse effect on the adhesive force, so it is not good.

[0044] (d) Heat curing agent

[0045] The high refractive index and high adhesiveness epoxy resin composition of the present invention may contain a thermosetting agent. The above thermosetting agent is a thermosetting polymer. If an epoxy resin is to exert its function, a curing agent that matches it is required, and the epoxy resin exhibits its inherent properties through the curing reaction initiated by the curing agent. In the past, amine, acid, and phenol curing agents were used. These curing agents were selected to have adhesiveness, electrical properties, and high-temperature and high-humidity resistance properties different from those of other plastic materials. Typically, the reaction of an epoxy resin with an amine curing agent is as follows. The amine curing agent attacks and opens the ring of the epoxy resin, and the epoxy-amine molecule that attaches to a specific position and becomes larger causes a chain reaction by attacking the surrounding epoxy resin. After the molecules with amines are almost consumed, the reaction ends, and this reaction to form a dense structure is called a curing reaction. This reaction necessarily generates hydroxyl groups, which not only significantly affect the adhesive force and the usable time of the product, but also cause poor moisture resistance, unstable reliability, and cracking.

[0046]

[0047] In the present invention, a latent thermal curing agent that preferably initiates a direct reaction between epoxy resins is used. In this reaction, hydroxyl groups are not generated as in the above-mentioned epoxy-amine reaction, and a cured product having a long fibrous molecular structure can be obtained. Therefore, different from the reaction of traditional epoxy resin-curing agent, a structure beneficial to long-term reliability can be obtained.

[0048]

[0049] As the latent thermal curing agent used herein, any or commercially available curing agents can be used. Specifically, one or more compounds selected from the group consisting of tetradecyl(trihexyl)phosphonium dicyanamide salt, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium methanesulfonate, tolylisopropylphenyl iodonium tetrakis(pentafluorophenyl)borate, Opton CP-66, Opton CP-77 (ADEKA Japan), 2-ethyl-4-methylimidazolium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, quaternary ammonium borate, (4-acetoxyphenyl)benzyl(methyl)sulfonium, tetrakis(pentafluorophenyl)borate, SI-B2, SI-B3, SI-B3A, SI-B4, SI-B7 (Sansei Chemical Industry Co., Ltd.) can be used.

[0050] In the present invention, the content of the latent thermal curing agent is preferably 0.5 to 5.0 parts by weight, more preferably 0.5 to 3.0 parts by weight, and even more preferably 0.5 to 1.5 parts by weight. If the content of the latent thermal curing agent is less than 0.5 part by weight, uncured products may be produced, which is not good. If the content is higher than 1.5 parts by weight, the pot life at normal or high temperatures may be shortened, there is a risk of poor heat generation during curing, and caking and hardening of the dispensing needle may occur accidentally during the dispensing process, thus affecting the use of the product by the user, which is not good.

[0051] In the present invention, as long as physical and chemical properties are exhibited, general latent curing agents can also be used instead of the latent thermal curing agents described above, and commercially available products can be used. For example, AJICURE MY-24, AJICURE MY-H, AJICURE PN-23, AJICURE PN-H, AJICURE PN-31, AJICURE PN-40, AJICURE PN-50, VDH, VDH-J, AH-154, ADH, DDH, SAH, IDH, SDH, LDH, UDH, ANCAMINE 2441, ANCAMINE 2442, ANCAMINE 2014AS, TECHNICURE LC-80, TECHNICURE LC-100, TECHNICURE LC-214, TECHNICURE MDU-11, TECHNICURE PDU-250, TECHNICURE IPDU-8, TECHNICURE TDU-200, EH-4357, NOVACURE HX-3721, NOVACURE HX-3722, NOVACURE HX-3748, NOVACURE HX-3741, NOVACURE HX-3742, NOVACURE HX-3088, NOVACURE HX-3613, NOVACURE HX-3921HP, NOVACURE HX-3941HP, NOVACURE HX-3932HP, FXR-1081, FXR-1020, FXR-1060, etc. can be used as latent curing agents, and they can be used alone or in combination of two or more. These latent curing agents have a microcapsule form in which an epoxy resin encapsulates an imidazole curing accelerator, so the curing of the epoxy resin composition can be promoted only at high temperatures of 80 to 100°C or lower, which can contribute to the storage stability at room temperature.

[0052] (e) Additives

[0053] The epoxy resin composition of the present invention may optionally and selectively contain additives. The additives are used to enhance the property of the epoxy resin composition flowing into the gap between the chip and the substrate, and incidentally prevent the occurrence of gap voids. For example, BYK018, BYK 019, BYK 021, BYK 024, BYK 066N, BYK 909, ethoxyethanol, polyethylene monoether glycol, etc. can be used, but are not limited thereto. The above substances can be used alone or in combination of two or more.

[0054] The content of the above-mentioned additive can be 0.01 to 1.0 parts by weight. If the content of the additive is less than 0.1 part by weight, the desired effect may not be obtained. If the content is higher than 1.0 part by weight, the fluidity may increase excessively, resulting in a decrease in physical properties, so it is not good.

[0055] Hereinafter, the present invention will be further described in detail by way of examples. The protection scope of the present invention is not limited to the following examples.

[0056] [Examples and Comparative Examples: Manufacturing of Epoxy Resin Composition]

[0057] Add high refractive index epoxy resin, diluted epoxy resin, and adhesive epoxy resin to a planetary mixer according to the components and contents in Table 1 below, and stir at normal temperature and normal pressure for 2 hours to form a uniform property with each other. Then, add a latent heat curing agent quantitatively and stir at normal temperature and normal pressure for 2 hours. After that, defoam under vacuum to obtain a viscous liquid.

[0058] [Table 1]

[0059] (Parts by weight) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 <![CDATA[D-1 (1) > 45.4 48.5 45.5- 45.5 40 <![CDATA[D-2 (2) > 6.5 7 - - 20 <![CDATA[D-3 (3) > - - 6.5 6.5 - <![CDATA[A-1 (4) > 33 29.5 33 33 33 <![CDATA[B-1 (5) > 15 15 15 - - <![CDATA[B-2 (6) > - - - 15 - <![CDATA[B-3 (7) > - - - - 15 <![CDATA[C (8) > 1.1 1.1 1.1 1.1 1.1

[0060] (1) D-1: Monofunctional liquid epoxy resin, 2-biphenylyl glycidylether

[0061] (2) D-2: Bifunctional solid epoxy resin, 2,2'-[[1,1'-binaphthalene]-2,2'-diylbis(oxymethylene)]bis-oxirane

[0062] (3) D-3: Polyfunctional liquid epoxy resin, fluorene-type epoxy compound (EG-200)

[0063] (4) A-1: Bifunctional liquid epoxy resin, (3',4'-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate

[0064] (5) B-1: Bifunctional liquid epoxy resin, bisphenol A-bisphenol A diglycidyl ether polymer

[0065] (6) B-2: Bifunctional liquid epoxy resin, bisphenol F diglycidyl ether

[0066] (7) B-3: Bifunctional oxetane epoxy resin, bis(1-ethyl(3-oxetanyl)methyl) ether (OXT-221)

[0067] (8) C: Latent thermal curing agent, phenyl amine borate

[0068] [Basic evaluation of epoxy resin composition]

[0069] The refractive index (liquid state), refractive index of cured product (thin film), viscosity, adhesive strength, and high-temperature stability (40 °C) of the epoxy resin compositions manufactured in Examples 1 to 2 and Comparative Examples 1 to 3 above were evaluated, and the results are shown in Table 2 below.

[0070] [Table 2]

[0071] Refractive index (liquid) 1.56 1.57 1.56 1.56 1.55 Refractive index (film) 1.60 1.61 1.59 1.59 1.58 Viscosity (mPa·s) 580 610 630 530 1600 <![CDATA[Adhesive force (kgf / cm 2 )]]> 6.5 6.5 6.0 6.0 6.0 High-temperature stability (40°C) 6 days 6 days 4 days 4 days 4 days <![CDATA[T g > 106 101 103 98 94 High-vacuum weight reduction -0.2 -0.2 -0.2 -0.7 -0.7

[0072] 1. Refractive index (liquid state): The refractive index of the epoxy resin composition was measured using an Abbe refractometer at 25 ± 5 °C.

[0073] 2. Refractive index (thin film): The thin film was attached to the prism, and the refractive indices in the thickness direction and the plane direction were measured by changing the incident angle of the laser beam. Measured using the 2010 / M from Metricon.

[0074] 3. Viscosity: Measured using a Brookfield DV2T viscometer, cone-plate type CPA-51Z rotor at 25 ± 5 °C, and the viscosity was recorded after 30 minutes.

[0075] 4. Adhesive strength: 0.01 g of the epoxy resin composition was coated on a 76 mm X 26 mm X 3 mm glass plate and then pressed, cured in an oven set at 100 °C for 60 minutes, and then the adhesive strength was measured using a UTM.

[0076] 5. High-temperature stability (40 °C): The epoxy resin composition and nitrogen were filled into a glass bottle sealed with a rubber stopper and placed at 40 ± 5 °C, and then the viscosity was measured on a daily basis. If the viscosity change rate was 1.2 times or less of the initial viscosity, it was recorded.

[0077] As shown in Table 2 above, it can be confirmed that the epoxy resin compositions produced in Examples 1 to 2 of the present invention have a liquid refractive index of 1.56 or more and a film refractive index of 1.60 or more, an appropriate viscosity level, high adhesive strength, and good storage stability. In particular, as shown in Examples 1 and 2, when using D-2, the refractive index shows an increasing trend. In addition, in the case of Examples 1 and 2 using B-1, the high-temperature stability shows an increasing trend. From the above physical property evaluations, it is confirmed that the epoxy resin compositions of Examples 1 to 2 can be effectively used as a sealant composition for display elements.

[0078] As described above in detail for specific parts of the present invention, it is obvious to those of ordinary skill in the art that such specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereto. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims

1. A high-refractive-index and high-adhesion epoxy resin composition, characterized in that, Comprising: (a) A high refractive index epoxy resin represented by the following Chemical Formula 1; (b) A highly reliable diluting epoxy resin containing an alicyclic group having 10 to 100 carbon atoms, which may be substituted or unsubstituted; and (c) A non-yellowing adhesive epoxy resin represented by the following Chemical Formula 2, [Chemical Formula 1] [Chemical Formula 2] In the said Chemical Formula 1, the ring represented by the dotted line is a group fused to the adjacent 6-membered ring structure, and is one of a substituted or unsubstituted C6-C60 monocyclic aryl group, a substituted or unsubstituted C6-C60 polycyclic aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 monocyclic heteroaryl group, and a substituted or unsubstituted C6-C60 polycyclic heteroaryl group. m and n are each independently an integer from 0 to 4, but not both 0 at the same time. In the chemical formula 2, G is an organic group containing a glycidyl group, X 1 and X 2 are each independently hydrogen or methyl, p is an integer from 1 to 10, and R is a substituted or unsubstituted C10-C100 alkylene or alkenylene group.

2. The high refractive index and high adhesiveness epoxy resin composition according to Claim 1, wherein the high refractive index and high adhesiveness epoxy resin composition comprises 50 to 80 parts by weight of a high refractive index epoxy resin, 5 to 30 parts by weight of a non-yellowing adhesive epoxy resin, and 10 to 50 parts by weight of a highly reliable diluting epoxy resin.

3. The high refractive index and high adhesiveness epoxy resin composition according to Claim 1, wherein the highly reliable diluting epoxy resin is produced by containing one or more compounds selected from the group consisting of dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, 2,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, dicyclopentadiene dioxide, and bis(3,4-epoxycyclohexylmethyl) adipate.

4. The high refractive index and high adhesiveness epoxy resin composition according to Claim 1, wherein the highly reliable diluting epoxy resin is produced by containing one or more compounds selected from the group consisting of the following A-1 to A-3.

5. The high refractive index and high adhesiveness epoxy resin composition according to Claim 1, which further comprises a thermal curing agent.

6. The high refractive index and high adhesiveness epoxy resin composition according to Claim 5, wherein the thermal curing agent is a latent thermal curing agent.

7. The high refractive index and high adhesiveness epoxy resin composition according to Claim 1, wherein the highly reliable diluting epoxy resin has a liquid refractive index of 1.56 or more and a film refractive index of 1.60 or more.

8. A sealing material for a display element, which comprises the high refractive index and high adhesiveness epoxy resin composition according to any one of Claims 1 to 7.

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