Electronic packaging adhesive for waterproof sealing, preparation method of electronic packaging adhesive and application of electronic packaging adhesive in electronic display technology

Abstract

The invention discloses an electronic packaging adhesive for waterproof sealing, a preparation method of the electronic packaging adhesive and application of the electronic packaging adhesive in an electronic display technology, and belongs to the technical field of epoxy structure adhesives. The electronic packaging adhesive is prepared from the following components in parts by mass: 10 to 20 parts of epoxy resin, 1 to 5 parts of flexibilizer, 10 to 20 parts of epoxy diluted resin, 0.1 to 5 parts of stabilizer, 0.1 to 5 parts of accelerant, 30 to 40 parts of hydrophobic inorganic filler and 20 to 40 parts of epoxy curing agent. According to the invention, an actual application scene is simulated, and the bonding performance of the prepared electronic packaging adhesive is verified through different performance index tests. According to the method disclosed by the invention, by optimizing a formula and a process, the curing temperature of the product is reduced, long operable time and low water vapor transmission rate are ensured, and the body strength, the bonding strength, the tolerance, the base material universality and the like of the product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy structural adhesives, and specifically relates to an electronic packaging adhesive for waterproof sealing, a preparation method thereof, and an application in electronic display technology. Background Art

[0002] With the leap of display technology, electronic price tags and electronic ink screens, as innovators in the field of information display, are leading a revolution in vision and interaction. Electronic ink, a cutting-edge material, is as flexible as traditional ink and can be widely printed on a variety of substrates, including but not limited to curved plastics, polyester films, paper and even cloth, showing unprecedented application potential. Its uniqueness lies in that the color of the display content can be changed by current driving, and the presentation of dynamic images gives the product the ability to update instantly like a smartphone, subverting the boundaries of traditional static displays and meeting people's visual and emotional needs.

[0003] Given the extreme sensitivity of electronic ink display to moisture conditions, ensuring the constant moisture content in the electronic ink layer is the key to ensuring clear and stable image quality of the electronic ink screen. Therefore, in the precision manufacturing process of the electronic ink screen, it is particularly important to introduce a high-performance waterproof sealing glue material. It needs to tightly seal the electronic ink microcapsules to prevent external water vapor from invading and internal water loss, so as to ensure the best performance of the electronic ink.

[0004] There are still multiple challenges in the research and development of materials such as glue for waterproof sealing: First, to achieve the ultimate water vapor barrier performance, to ensure the bidirectional isolation of the electronic ink screen inside and outside, and to maintain the cleanliness and stability of its internal environment; second, to pursue low-temperature curing technology. First, high-temperature curing will affect the morphology of the electronic price tag protective film, thereby causing a difference in the size of the film and the glass substrate and affecting the sealing effect. Secondly, low-temperature curing meets the specific requirements of electronic ink for the optimal display temperature, and the ideal curing temperature should be controlled below 80°C; third, to enhance the penetration ability of electronic packaging glue to adapt to the electronic price tag assembly process, and to accurately and efficiently fill the glue into the gap between the film material and the glass substrate through the siphon effect to ensure the integrity and firmness of the seal.

[0005] Looking back at the existing technology, although there have been breakthroughs in tensile strength such as epoxy-modified silicone sealants (patent application number 201810607208.8), it is still difficult to match the performance of polyurethane sealants; although the pressure-sensitive adhesive for electronic tags (patent application number 201110086180.6) has pressure-sensitive properties, it has poor stability in high temperature and high humidity environments; and the single-component epoxy structural adhesive for waterproof sealing (patent application number 201910847255.4) has excellent performance, its complex preparation process limits its application in large-scale production.

[0006] Looking to future development, the research and development of waterproof sealing glue must not only continue to optimize its bonding performance and functionality, but also take into account cost-effectiveness to meet the cost control and efficiency requirements of industrial production, and promote the popularization and application of this innovative technology in a wider range of fields. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide an electronic packaging adhesive for waterproof sealing.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions, including:

[0011] 10-20 parts of epoxy resin, 1-5 parts of toughening agent, 10-20 parts of epoxy dilution resin, 0.1-5 parts of stabilizer, 0.1-5 parts of accelerator, 30-40 parts of hydrophobic inorganic filler, and 20-40 parts of epoxy curing agent.

[0012] As a preferred embodiment of the waterproof sealing electronic packaging glue described in the present invention, the epoxy resin includes bisphenol A-based diglycidyl ether, bisphenol F-based diglycidyl ether, bisphenol S-based diglycidyl ether, bisphenol Z-based diglycidyl ether, polybutadiene-modified diglycidyl ether, and their halides and hydrides.

[0013] As a preferred embodiment of the waterproof and sealed electronic packaging adhesive of the present invention, the epoxy dilution resin includes resorcinol diglycidyl ether REDG; and the toughening agent includes MX154.

[0014] As a preferred embodiment of the waterproof sealing electronic packaging adhesive described in the present invention, the stabilizer is an organic acid, including one or more of salicylic acid, citric acid, malic acid, and succinic acid; the promoter is an organic amine, including one or more of tertiary amine, K54, DMAP, and DMP.

[0015] As a preferred embodiment of the waterproof and sealed electronic packaging glue described in the present invention, the hydrophobic inorganic filler includes one or more of silicon dioxide, diatomaceous earth, aluminum oxide, zinc oxide, iron oxide, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, calcium silicate, talc, glass beads, bentonite, aluminum nitride or silicon nitride.

[0016] As a preferred embodiment of the waterproof and sealed electronic packaging adhesive of the present invention, the epoxy curing agent is an amine curing agent.

[0017] As a preferred embodiment of the waterproof and sealed electronic packaging adhesive of the present invention, the amine curing agent comprises a non-latent amine curing agent and a latent amine curing agent.

[0018] As a preferred embodiment of the waterproof and sealed electronic packaging adhesive of the present invention, the non-latent curing agent includes aliphatic amines, aromatic amines, polyether amines, phenolic amines and modified amines thereof.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing an electronic packaging adhesive for waterproof sealing.

[0020] In order to solve the above technical problems, the present invention provides the following technical solutions, including:

[0021] Take epoxy resin, toughening agent, epoxy diluent resin, stabilizer and accelerator, stir at a speed of 800 to 1200 rpm for 20 to 40 minutes, then add hydrophobic inorganic filler, continue stirring for 20 to 40 minutes, cool to room temperature, add epoxy curing agent, continue stirring for 5 to 10 minutes to obtain a mixture;

[0022] The mixture is stirred at a rotation speed of 1800-2200 rpm for 25-35 seconds, and the stirring is repeated 3-5 times to mix evenly to obtain an electronic packaging adhesive for waterproof sealing.

[0023] The third object of the present invention is to overcome the deficiencies in the prior art and provide an application of a waterproof and sealed electronic packaging adhesive in electronic display technology.

[0024] Beneficial effects of the present invention:

[0025] (1) The electronic packaging adhesive for waterproof sealing of the present invention has the advantages of high body strength, good bonding strength, low water vapor permeability, good high temperature and high humidity resistance and high temperature and low humidity resistance, wide substrate universality, good bonding performance to substrates such as metal, glass, and plastic, and no need for primer, etc.

[0026] (2) The present invention reduces the water absorption rate and water vapor transmission rate of the electronic packaging glue for waterproof sealing by adjusting the cross-linking density of the system and adding highly hydrophobic fillers, thereby improving its high temperature and high humidity resistance and high temperature and low humidity resistance.

[0027] (3) The electronic packaging adhesive for waterproof sealing prepared by the present invention provides a third option for the waterproof sealing application of electronic products in addition to silicone sealants and polyurethane sealants.

[0028] (4) The present invention has great practical applicability, and considering cost-effectiveness, a small number of raw materials, simple operation, and is suitable for large-scale production needs.

[0029] (5) The present invention provides a low temperature curing epoxy sealant that can be cured at 60°C and meet a working time window of up to 4 hours. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] The raw materials used in the present invention are all commercially available unless otherwise specified.

[0034] The performance of the material prepared in the embodiment of the present invention was tested as follows:

[0035] Viscosity test: Refer to GB / T 2794-2022 and measure by rotational rheometer method.

[0036] Room temperature stability test: refer to GB / T 29174-2012, measured by differential scanning calorimetry, test conditions are 25℃, 96h.

[0037] 60℃ constant temperature test: Place 50g of the test gel sample in a sealed transparent container and observe the changes in the gel sample after 1 hour at 60℃. "Gel" means gel.

[0038] Adhesion test: refer to GB / T 7124-86, the glass and nylon substrates used for testing are scrubbed with ethanol to remove oil, the glue sample is applied to the surface to be bonded, the glass PET substrate is closed, and the thickness of the glue layer is controlled by a 125μm iron wire; after the treatment, it is placed in an oven preheated to 60℃, and the timing starts for 1h when the oven returns to 60℃, the sample is taken out and placed at room temperature for 24h; finally, the test is carried out on a tensile testing machine.

[0039] Boiling sealing test: After dispensing glue into the integrated bracket, heat and cure it. Place the cured integrated bracket in a 100mL beaker and add 1:1 red ink and anhydrous ethanol; put the beaker in a 100℃ water bath for boiling, and observe and record the experimental phenomena as time goes by.

[0040] Example 1

[0041] This embodiment provides a method for preparing an electronic packaging adhesive for waterproof sealing, specifically:

[0042] 15 parts of epoxy resin (bisphenol F-based diglycidyl ether), 3 parts of epoxy resin toughener (MX154), 15 parts of epoxy diluent resin (resorcinol diglycidyl ether REDG), 0.5 parts of stabilizer (salicylic acid) and 1 part of accelerator (K54) were weighed in sequence, and 15 parts of hydrophobic inorganic filler (SiO2) were added after stirring at a speed of 1000 rpm for 30 minutes, and stirring was continued for 30 minutes. After cooling to room temperature, 20 parts of epoxy curing agent (polyetheramine T403) were added, and stirring was continued for 5 minutes to obtain a mixture;

[0043] The mixture was stirred at a rotation speed of 2000 rpm for 30 seconds, and the stirring was repeated 3 times. The mixture was mixed evenly and discharged to obtain an electronic packaging adhesive for waterproof sealing.

[0044] Example 2

[0045] The difference between this embodiment and embodiment 1 is that the amount of epoxy resin added is adjusted to 10 parts, and the rest of the preparation process is the same as that of embodiment 1, to prepare electronic packaging glue for waterproof sealing.

[0046] Example 3

[0047] The difference between this embodiment and embodiment 1 is that the amount of epoxy resin added is adjusted to 20 parts, and the rest of the preparation process is the same as that of embodiment 1, to prepare electronic packaging glue for waterproof sealing.

[0048] The performance of the material prepared in the above embodiment was tested, and the comparison between the test results and embodiment 1 is shown in Table 1.

[0049] Table 1

[0050] Example 1 Example 2 Example 3 Viscosity 400cps 380cps 450cps Room temperature stability 4h 4h 4h Constant temperature test Gel Gel Gel Adhesion >8MPa >8MPa >8MPa Boil tightness >10 days >9 days >9 days

[0051] As can be seen from the table above, adjusting the content of epoxy resin has a significant impact on the performance of electronic packaging glue for waterproof sealing. This is because the amount of epoxy resin added directly affects the viscosity of the colloid. The molecular weight of epoxy resin is large and the intermolecular force is strong, so increasing the amount of epoxy resin added will increase the viscosity of the colloid. The increase in viscosity will affect the fluidity and permeability of the colloid, which is crucial for electronic packaging glue because they need to be able to fully fill the space between components and wires. High viscosity may cause the colloid to flow poorly and it is difficult to achieve uniform distribution, thus affecting the packaging effect.

[0052] Too much epoxy resin may cause the cured colloid to be too rigid and lack flexibility. During the boiling process, due to thermal expansion and water penetration, the rigid colloid may not be able to adapt to the expansion and contraction of the substrate, resulting in a decrease in sealing performance and an increase in curing shrinkage, thereby generating internal stress during the curing process, affecting the bonding strength between the colloid and the substrate, and further affecting the sealing performance after boiling. In summary, the preferred amount of epoxy resin added in the present invention is 15 parts.

[0053] Example 4

[0054] The difference between this embodiment and embodiment 1 is that the addition amount of epoxy dilution resin is adjusted to 10 parts, and the rest of the preparation process is the same as that of embodiment 1 to prepare electronic packaging glue for waterproof sealing.

[0055] Example 5

[0056] The difference between this embodiment and embodiment 1 is that the addition amount of epoxy dilution resin is adjusted to 20 parts, and the rest of the preparation process is the same as that of embodiment 1, and the electronic packaging adhesive for waterproof sealing is prepared.

[0057] The performance of the material prepared in the above embodiment was tested, and the comparison between the test results and embodiment 1 is shown in Table 2.

[0058] Table 2

[0059] Example 1 Example 4 Example 5 Viscosity 400cps 500cps 250cps Room temperature stability 4h 4.5h 3.5h Constant temperature test Gel Gel Gel Adhesion >8MPa >8MPa >8MPa Boil tightness >10 days >9 days >9 days

[0060] As can be seen from the above table, adjusting the amount of epoxy dilution resin added has a significant effect on the performance of the electronic packaging glue for waterproof sealing. This is because the epoxy dilution resin may affect the cross-linking density and network structure of the electronic packaging glue. If the cross-linking density is too low, the mechanical strength and heat resistance of the colloid may decrease; if the cross-linking density is too high, the flexibility and impact resistance of the colloid may be affected. In summary, the preferred amount of multifunctional epoxy resin added in the present invention is 15 parts.

[0061] Comparative Example 1

[0062] The difference between this embodiment and embodiment 1 is that the epoxy curing agent is adjusted to 10 parts each of polyetheramine T403 and PN-23, and the rest of the preparation process is the same as that of embodiment 1 to prepare electronic packaging adhesive for waterproof sealing.

[0063] Comparative Example 2

[0064] The difference between this embodiment and embodiment 1 is that the epoxy curing agent is adjusted to 20 parts of PN-23, and the rest of the preparation process is the same as that of embodiment 1 to prepare an electronic packaging adhesive for waterproof sealing.

[0065] Comparative Example 3

[0066] The difference between this embodiment and embodiment 1 is that the amount of the accelerator added is adjusted to 0, and the rest of the preparation process is the same as that of embodiment 1, and an electronic packaging adhesive for waterproof sealing is prepared.

[0067] Comparative Example 4

[0068] The difference between this comparative example and Example 1 is that the amount of the accelerator added is adjusted to 0, the type of epoxy curing agent is PN-23, and the rest of the preparation process is the same as Example 1 to prepare an electronic packaging adhesive for waterproof sealing.

[0069] Comparative Example 5

[0070] The difference between this comparative example and Example 1 is that the amount of the stabilizer added is adjusted to 0, and the rest of the preparation process is the same as that of Example 1 to prepare an electronic packaging adhesive for waterproof sealing.

[0071] The performance of the material prepared in the above embodiment was tested, and the comparison between the test results and embodiment 1 is shown in Table 3.

[0072] Table 3

[0073]

[0074] From the above results, it can be seen that the electronic packaging glue for waterproof sealing of the present invention has the advantages of high body strength, good bonding strength, low water vapor permeability, good high temperature and humidity resistance, high temperature and low humidity performance, wide substrate universality, and good bonding performance for metal, glass, plastic and other substrates. The sealant system of the present invention can be cured at 60°C and meet a long working time. The present invention reduces the water absorption and water vapor permeability of the single-component electronic packaging glue for waterproof sealing by adjusting the cross-linking density of the system and adding highly hydrophobic fillers, thereby improving its high temperature and humidity resistance, high temperature and low humidity performance; it provides a third option for the waterproof sealing application of electronic products in addition to silicone sealants and polyurethane sealants.

[0075] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An electronic packaging adhesive for waterproof sealing, characterized in that: In parts by mass, including: 10-20 parts of epoxy resin, 1-5 parts of toughening agent, 10-20 parts of epoxy dilution resin, 0.1-5 parts of stabilizer, 0.1-5 parts of accelerator, 30-40 parts of hydrophobic inorganic filler, and 20-40 parts of epoxy curing agent.

2. The electronic packaging adhesive for waterproof sealing as claimed in claim 1, characterized in that: The epoxy resin includes bisphenol A-based diglycidyl ether, bisphenol F-based diglycidyl ether, bisphenol S-based diglycidyl ether, bisphenol Z-based diglycidyl ether, polybutadiene-modified diglycidyl ether, and halides and hydrides thereof.

3. The waterproof electronic packaging adhesive as claimed in claim 1, characterized in that: The epoxy dilution resin includes resorcinol diglycidyl ether REDG; and the toughening agent includes MX154.

4. The electronic packaging adhesive for waterproof sealing as claimed in claim 1, characterized in that: The stabilizer is an organic acid, including one or more of salicylic acid, citric acid, malic acid, and succinic acid; the accelerator is an organic amine, including one or more of tertiary amine, K54, DMAP, and DMP.

5. The waterproof electronic packaging adhesive as claimed in claim 1, characterized in that: The hydrophobic inorganic filler includes one or more of silicon dioxide, diatomaceous earth, aluminum oxide, zinc oxide, iron oxide, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, calcium silicate, talc, glass beads, bentonite, aluminum nitride or silicon nitride.

6. The waterproof electronic packaging adhesive as claimed in claim 1, characterized in that: The epoxy curing agent is an amine curing agent.

7. The electronic packaging adhesive for waterproof sealing as claimed in claim 6, characterized in that: The amine curing agent includes a non-latent amine curing agent and a latent amine curing agent.

8. The electronic packaging adhesive for waterproof sealing as claimed in claim 7, characterized in that: The non-latent curing agent includes aliphatic amine, aromatic amine, polyether amine, phenolic amine and modified amine thereof.

9. A method for preparing the waterproof electronic packaging adhesive according to any one of claims 1 to 8, characterized in that: include, Take epoxy resin, toughening agent, epoxy diluent resin, stabilizer and accelerator, stir at a speed of 800 to 1200 rpm for 20 to 40 minutes, then add hydrophobic inorganic filler, continue stirring for 20 to 40 minutes, cool to room temperature, add epoxy curing agent, continue stirring for 5 to 10 minutes to obtain a mixture; The mixture is stirred at a rotation speed of 1800-2200 rpm for 25-35 seconds, and the stirring is repeated 3-5 times to mix evenly to obtain an electronic packaging adhesive for waterproof sealing.

10. Use of the waterproof and sealed electronic packaging adhesive as claimed in any one of claims 1 to 8 in electronic display technology.

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