Modified epoxy resin composition for packaging GOB display screen

Abstract

The invention relates to a modified epoxy resin composition for GOB display screen packaging, and belongs to the technical field of epoxy polymer preparation. The composition comprises the following raw materials in parts by weight: 100 parts of matrix epoxy resin, 30-60 parts of an accelerant, 20-40 parts of modified graphene, 100-200 parts of a curing agent and 10-30 parts of a reactive diluent, the promoting material is prepared from epoxy resin DGEBA and functionalized pentaerythritol spirocyclic phosphate through a thermal reaction. According to the invention, by introducing the promoting material and the modified graphene, the finally obtained epoxy resin is endowed with weather resistance and heat dissipation performance, and the modified graphene is modified by the amino silane coupling agent, so that the finally obtained epoxy resin has a stable heat dissipation network; the promoting material is bisphenol A epoxy resin containing functional branched chains, so that the heat resistance and excellent weather resistance of the finally obtained epoxy resin are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy polymer preparation, and in particular relates to a modified epoxy resin composition for GOB display screen packaging. Background Art

[0002] GOB, the full name of which is GLUE ON THE BOARD, is a special packaging method for LED display screens. Simply put, after fixing the LED lamp beads on the PCB (printed circuit board), a special optical thermal conductive nano-scale potting material is used to fill the gaps between the lamp beads to form a tightly connected and highly protected whole. The potting glue used in the existing GOB display screen packaging technology must have excellent adhesion properties to ensure the connection strength between the packaged lamp beads and the PCB board, reduce the risk of the lamp beads falling off, and have good optical properties and high heat dissipation performance. Among them, good optical properties will not affect the luminous performance of the LED lamp, and high heat dissipation can ensure that the heat generated by the LED lamp beads can be dissipated in time, reduce the working temperature of the lamp beads, and ensure the service life of the display screen. Among the existing potting glues, the glue with strong adhesion is epoxy resin glue, but when it is used for GOB display screen packaging, its weather resistance and heat dissipation performance are difficult to meet the requirements of potting glue for GOB display screen packaging.

[0003] Therefore, it is necessary to provide a modified epoxy resin composition with good weather resistance and heat dissipation performance to meet the requirements of potting glue for GOB display screen packaging. Summary of the invention

[0004] The object of the present invention is to provide a modified epoxy resin composition for GOB display screen encapsulation.

[0005] The technical problem to be solved by the present invention is to improve the weather resistance and heat dissipation performance of the existing epoxy resin.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A modified epoxy resin composition for GOB display screen packaging comprises the following raw materials in parts by weight: 100 parts of base epoxy resin, 30-60 parts of accelerator, 20-40 parts of modified graphene, 100-200 parts of curing agent and 10-30 parts of active diluent.

[0008] Furthermore, the accelerator is prepared by thermal reaction of epoxy resin DGEBA and functionalized pentaerythritol spirocyclic phosphate;

[0009] Furthermore, the functionalized pentaerythritol spirocyclic phosphate is prepared by reacting pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine.

[0010] Furthermore, the pentaerythritol spirocyclic phosphate is prepared by reacting pentaerythritol and phosphorus oxychloride, and the molecular structure is as follows:

[0011]

[0012] The detailed preparation method can be referred to the content of "Preparation of intermediate pentaerythritol spirocyclic phosphate" in Chapter 2 of "Preparation of phosphorus-based flame retardant spirocyclic phosphate bisphenol-S and its application in resin", and the present invention will not repeat it here.

[0013] Furthermore, the mass ratio of the epoxy resin DGEBA to the functionalized pentaerythritol spirocyclic phosphate is 100:60-80.

[0014] Furthermore, the molecular structure formula of the epoxy resin DGEBA is shown below.

[0015]

[0016] Furthermore, the reaction conditions of the thermal reaction are: in the presence of the first organic solvent and the first acid binding agent, heating to 50-70° C. and stirring the reaction for 6-24 hours.

[0017] Furthermore, the first organic solvent is one of tetrahydrofuran, toluene and benzene; the first acid binding agent is one of triethylamine, pyridine, sodium carbonate and potassium carbonate.

[0018] Furthermore, in the reaction of the pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine, the molar ratio of the pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine is 1:1-1.1.

[0019] Furthermore, in the reaction of pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine, the reaction conditions are: heating to 0-30° C. and stirring the reaction for 3-6 hours in the presence of a second organic solvent and a second acid binding agent.

[0020] Furthermore, the second organic solvent is one of dichloromethane and tetrahydrofuran; the second acid binding agent is one of triethylamine, pyridine, sodium carbonate and potassium carbonate.

[0021] Preferably, the reaction of pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine is specifically performed as follows:

[0022] After pentaerythritol spirocyclic phosphate, the second acid-binding agent and the second organic solvent are uniformly mixed, the second organic solvent containing 2,2,6,6-tetramethylpiperidinamine is added dropwise to the mixture under ice-water bath and stirring. After the addition is completed, the mixture is heated to 20-30°C and stirred for reaction for 2-4 hours. After post-treatment, functionalized pentaerythritol spirocyclic phosphate is obtained.

[0023] Furthermore, the modified graphene is prepared by a surface modification reaction of an aminosilane coupling agent and graphene oxide.

[0024] Furthermore, the conditions of the surface modification reaction are: heating to 50-60° C. and stirring the reaction for 4-12 hours in the presence of ethanol and water.

[0025] Furthermore, the mass ratio of the graphene oxide to the aminosilane coupling agent is 10:1-2.5.

[0026] Furthermore, the curing agent is one or any combination of phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylphthalic anhydride.

[0027] Furthermore, the active diluent is one of propylene oxide propylene ether and butyl glycidyl ether.

[0028] Furthermore, the base epoxy resin is one of bisphenol A type epoxy resins.

[0029] Beneficial effects of the present invention:

[0030] The modified epoxy resin composition for GOB display screen encapsulation of the present invention is endowed with weather resistance and heat dissipation of the finally obtained epoxy resin by introducing a promoter and modified graphene, wherein the modified graphene is not only evenly dispersed in the epoxy resin through modification by an aminosilane coupling agent to form a good heat dissipation network, but also, due to the use of the aminosilane coupling agent, the aforementioned heat dissipation network is promoted to exist in the form of chemical bonding (crosslinking of amino groups and epoxy groups), thereby stabilizing the heat dissipation network; the promoter is a bisphenol A type epoxy resin containing functional branches, wherein the functional branches promote the complexity of the finally obtained epoxy resin interpenetrating network on the one hand, and on the other hand, introduce a high flame retardant segment (spirocyclic phosphate) and a weather resistant segment (hindered amine structure) into the aforementioned interpenetrating network, the high flame retardant segment and the modified graphene jointly improve the heat resistance of the finally obtained epoxy resin, and the weather resistant segment endows the finally obtained epoxy resin with excellent weather resistance. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] Preparation of accelerator:

[0034] A1. After uniformly mixing 0.1 mol pentaerythritol spirocyclic phosphate, 0.1 mol triethylamine and 100 mL dichloromethane, 50 mL dichloromethane containing 0.1 mol 2,2,6,6-tetramethylpiperidinamine was added dropwise to the mixture under ice-water bath and stirring. After the addition, the mixture was heated to 25°C and stirred for 4 h. The mixture was washed with water, and dichloromethane was recovered from the organic phase and dried to obtain functionalized pentaerythritol spirocyclic phosphate.

[0035] A2. After uniformly mixing 60 g of functionalized pentaerythritol spirocyclic phosphate, 150 mL of tetrahydrofuran, 100 g of epoxy resin DGEBA and 10 g of triethylamine, the mixture was heated to 55° C. and stirred for reaction for 24 h. The mixture was rotary evaporated, washed with water and dried to obtain a promoter.

[0036] Example 2

[0037] Preparation of accelerator:

[0038] A1. After uniformly mixing 0.1 mol pentaerythritol spirocyclic phosphate, 0.1 mol triethylamine and 100 mL tetrahydrofuran, 50 mL tetrahydrofuran containing 0.1 mol 2,2,6,6-tetramethylpiperidinamine was added dropwise to the mixture under ice-water bath and stirring. After the addition, the mixture was heated to 30°C and stirred for 2 h. The mixture was subjected to rotary evaporation, washed with water and dried to obtain functionalized pentaerythritol spirocyclic phosphate.

[0039] A2. After uniformly mixing 80 g of functionalized pentaerythritol spirocyclic phosphate, 150 mL of toluene, 100 g of epoxy resin DGEBA and 10 g of triethylamine, the mixture was heated to 65° C. and stirred for reaction for 6 h. The mixture was rotary evaporated, washed with water and dried to obtain a promoter.

[0040] Example 3

[0041] Preparation of modified graphene:

[0042] 100 g of graphene oxide was ultrasonically dispersed in a mixed solution of 20 mL of water and 180 mL of ethanol, and then 10 g of aminosilane coupling agent (KH-550) was added at 50 ° C with stirring, and the reaction was stirred for 12 hours, aged, separated, and the precipitate was taken, washed with water, washed with ethanol, and dried to obtain modified graphene.

[0043] Example 4

[0044] Preparation of modified graphene:

[0045] 100 g of graphene oxide was ultrasonically dispersed in a mixed solution of 20 mL of water and 180 mL of ethanol, and then 25 g of aminosilane coupling agent (KH-550) was added at 60 ° C with stirring, and the reaction was stirred for 4 hours, aged, separated, and the precipitate was taken, washed with water, washed with ethanol, and dried to obtain modified graphene.

[0046] Example 5

[0047] Preparation of modified epoxy resin:

[0048] Prepare the following raw materials in parts by weight: 100 parts of base epoxy resin (epoxy resin DGEBA), 30 parts of accelerator prepared in Example 1, 20 parts of modified graphene prepared in Example 3, 130 parts of curing agent (phthalic anhydride), and 10 parts of active diluent (propylene oxide propylene ether); after uniformly mixing the above raw materials in parts by weight, cure them to obtain modified epoxy resin.

[0049] Example 6

[0050] Preparation of modified epoxy resin:

[0051] Prepare the following raw materials in parts by weight: 100 parts of base epoxy resin (epoxy resin DGEBA), 45 parts of accelerator prepared in Example 2, 30 parts of modified graphene prepared in Example 4, 150 parts of curing agent (phthalic anhydride), and 20 parts of active diluent (propylene oxide propylene ether); after uniformly mixing the above raw materials in parts by weight, cure them to obtain modified epoxy resin.

[0052] Example 7

[0053] Preparation of modified epoxy resin:

[0054] Prepare the following raw materials in parts by weight: 100 parts of base epoxy resin (epoxy resin DGEBA), 60 parts of accelerator prepared in Example 1, 40 parts of modified graphene prepared in Example 3, 200 parts of curing agent (phthalic anhydride), and 30 parts of active diluent (propylene oxide propylene ether); after uniformly mixing the above raw materials in parts by weight, cure them to obtain modified epoxy resin.

[0055] Comparative Example 1

[0056] Preparation of modified epoxy resin: Compared with Example 5, an equal amount of modified graphene in the raw material is replaced by graphene oxide, and the rest is the same.

[0057] Comparative Example 2

[0058] Preparation of modified epoxy resin: Compared with Example 5, the accelerator in the raw materials was replaced with epoxy resin DGEBA, and the rest was the same.

[0059] Comparative Example 3

[0060] Preparation of modified epoxy resin: Compared with Example 5, the accelerator in the raw material is replaced with the accelerator prepared by the following steps:

[0061] 60 g of pentaerythritol spirocyclic phosphate, 150 mL of tetrahydrofuran, 100 g of epoxy resin DGEBA and 10 g of triethylamine were mixed evenly, heated to 50° C., stirred for reaction for 24 h, rotary evaporated, washed with water and dried to obtain a promoter.

[0062] Comparative Example 4

[0063] Preparation of modified epoxy resin: Compared with Example 5, the promoter and modified graphene in the raw materials were deleted, and the rest were the same.

[0064] The modified epoxy resins obtained in Examples 5-7 and Comparative Examples 1-3 were subjected to physical property tests, and the results are shown in Table 1, wherein the UV aging resistance was tested according to GB / T 16422.3, and the test time was 168 hours, and then the tensile strength was tested, and the decrease rate of the tensile strength was calculated;

[0065] Table 1

[0066] Tensile Strength Heat Deflection Temperature UV aging resistance Flame retardant grade Thermal conductivity GB / T 1040.2 ISO 75-2 GB / T 16422.3 UL-94 ASTMD5470-1 unit Mpa ℃ ％ \ <![CDATA[W·(m·K) -1 ]]> Example 5 14.5 116 5.9 V-1 1.17 Example 6 15.8 121 4.3 V-1 1.34 Example 7 17.0 125 4.0 V-1 1.45 Comparative Example 1 9.4 115 6.0 V-1 0.88 Comparative Example 2 10.9 102 16.5 V-2 1.14 Comparative Example 3 11.5 115 16.3 V-1 1.15 Comparative Example 4 10.3 92 17.7 V-3 0.22

[0067] It can be seen from the data in Table 1 that the modified epoxy resins obtained in Examples 5-7 have good weather resistance and heat dissipation properties.

[0068] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0069] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A modified epoxy resin composition for GOB display screen encapsulation, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of base epoxy resin, 30-60 parts of accelerator, 20-40 parts of modified graphene, 100-200 parts of curing agent and 10-30 parts of active diluent; The accelerator is prepared by thermal reaction of epoxy resin DGEBA and functionalized pentaerythritol spirocyclic phosphate; The functionalized pentaerythritol spirocyclic phosphate is prepared by reacting pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine.

2. A modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: The mass ratio of the epoxy resin DGEBA to the functionalized pentaerythritol spirocyclic phosphate is 100:60-80.

3. A modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: The reaction conditions of the thermal reaction are: in the presence of the first organic solvent and the first acid binding agent, heating to 50-70° C. and stirring the reaction for 6-24 hours.

4. A modified epoxy resin composition for GOB display screen encapsulation according to claim 3, characterized in that: The first organic solvent is one of tetrahydrofuran, toluene and benzene; the first acid binding agent is one of triethylamine, pyridine, sodium carbonate and potassium carbonate.

5. A modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: In the reaction of the pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine, the molar ratio of the pentaerythritol spirocyclic phosphate to 2,2,6,6-tetramethylpiperidinamine is 1:1-1.

1.

6. A modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: In the reaction of pentaerythritol spirocyclic phosphate and 2,2,6,6-tetramethylpiperidinamine, the reaction conditions are: heating to 0-30° C. and stirring the reaction for 3-6 hours in the presence of a second organic solvent and a second acid binding agent.

7. A modified epoxy resin composition for GOB display screen encapsulation according to claim 6, characterized in that: The second organic solvent is one of dichloromethane and tetrahydrofuran; the second acid binding agent is one of triethylamine, pyridine, sodium carbonate and potassium carbonate.

8. The modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: The modified graphene is prepared by a surface modification reaction of an aminosilane coupling agent and graphene oxide.

9. A modified epoxy resin composition for GOB display screen encapsulation according to claim 8, characterized in that: The conditions of the surface modification reaction are: heating to 50-60° C. and stirring the reaction for 4-12 hours in the presence of ethanol and water.

10. The modified epoxy resin composition for GOB display screen encapsulation according to claim 1, characterized in that: The curing agent is one or any combination of phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylphthalic anhydride; the active diluent is one of propylene oxide propylene ether and butyl glycidyl ether.

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