Medium temperature curing surface matting epoxy resin composition, preparation method and application thereof

Abstract

The present application relates to a final writing of the surface curing matte epoxy resin composition, the composition includes epoxy resin and several auxiliary materials, the weight of the epoxy resin is 100 parts by weight, the auxiliary materials include 10-15 parts by weight of diluent, 50-70 parts by weight of filler, 15-35 parts by weight of curing agent and 3-8 parts by weight of auxiliary agent. The provided potting composition is single-component package, without on-site preparation, avoiding the error and material waste generated in the weighing and mixing process of multi-component materials, simplifying the construction process, especially suitable for automatic assembly line operation, significantly improving the production efficiency and product consistency.

Description

Technical Field

[0001] This invention relates to the field of electronic packaging materials technology, and in particular to medium-temperature curing matte epoxy resin compositions, their preparation methods, and applications. Background Technology

[0002] Epoxy resin potting compounds are widely used for the encapsulation and protection of electronic components due to their excellent electrical insulation, chemical resistance, and mechanical strength. Currently, commercially available epoxy resin potting compounds are mainly multi-component systems, meaning the resin component and the curing agent component are packaged separately. During use, operators need to weigh and mix them according to the specified ratio. This not only increases the application process but also frequently results in weighing errors and uneven mixing, directly affecting the final performance of the potting compound and making it difficult to meet the requirements of modern automated production lines for material consistency and ease of operation.

[0003] Furthermore, the curing agents used in existing epoxy resin potting compounds (such as polyamines, acid anhydrides, and phenols) typically produce a glossy or high-gloss finish after curing. However, in certain applications (such as optical sensors, internal components of instruments requiring anti-reflective properties, or electronic modules with specific aesthetic requirements), a matte finish with no reflective light is desired. Existing potting materials cannot stably achieve a matte surface through simple formulation adjustments, limiting their application range. Therefore, developing a medium-temperature curing epoxy resin potting compound that can be packaged as a single component, is easy to handle, and can stably form a matte surface has significant application value. Summary of the Invention

[0004] Therefore, it is necessary to provide a medium-temperature curing matte epoxy resin composition, its preparation method, and its application to address the above-mentioned problems.

[0005] A medium-temperature curing matte epoxy resin composition, the composition comprising an epoxy resin and several excipients, wherein the epoxy resin is in the amount of 100 parts by weight, and the excipients include 10-15 parts by weight of diluent, 50-70 parts by weight of filler, 15-35 parts by weight of curing agent and 3-8 parts by weight of additives.

[0006] Preferably, the epoxy resin is selected from bisphenol A type epoxy resin E51 and / or bisphenol A type epoxy resin E44, and the diluent is selected from epoxy diluent AGE (alkyl glycidyl ether) or 678 diluent.

[0007] Preferably, the curing agent comprises curing agent A and / or curing agent B prepared by the following method: curing agent A is prepared by mixing and melting 1.65 parts by weight of 2-ethyl-4-methylimidazolium, 0.25 parts by weight of diaminodiphenylmethane, 0.56 parts by weight of methyltetrahydrophthalic anhydride, 1.24 parts by weight of toluene diisocyanate and 2.4 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher; curing agent B is prepared by mixing and melting 1.65 parts by weight of diethylimidazolium, 1.01 parts by weight of triethylamine, 0.65 parts by weight of cyanuric chloride, 0.56 parts by weight of methyltetrahydrophthalic anhydride and 1.85 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher.

[0008] Preferably, the curing agent further includes at least one of organic hydrazide DICY or thiourea.

[0009] Preferably, the filler is selected from one or more of 325-mesh or 1250-mesh activated silica powder, wollastonite, and alumina; the additives include coupling agents, leveling agents, defoamers, dispersants, and pigments.

[0010] Preferably, the coupling agent is one or more of KH550, KH560, or titanate coupling agents; the pigment is one or more of phthalocyanine blue BGS color paste, phthalocyanine blue BS color paste, or rutile titanium dioxide.

[0011] Preferably, the auxiliary materials further include a flame retardant, which is a phosphorus-nitrogen composite flame retardant.

[0012] A method for preparing a medium-temperature curing matte epoxy resin composition, wherein the composition is prepared using the epoxy resin potting compound composition according to any one of claims 1-7 as raw material, and the preparation method includes the following steps. S1, Weigh the epoxy resin, diluent, curing agent and additives according to the weight parts, and stir them evenly to obtain a mixture; S2, add filler to the mixture and grind it on a three-roll mill until the fineness reaches 500 mesh or more; S3, the ground mixture is transferred to a vacuum mixing tank and vacuumed under stirring to remove air bubbles, thus obtaining the potting compound composition.

[0013] Preferably, in step S3, the stirring speed of the vacuum mixing tank is 24 rpm, the vacuum degree is -0.08 MPa, and the vacuuming time is 2-3 hours.

[0014] Application of a medium-temperature curing matte epoxy resin potting compound composition as described in any one of claims 1-7 in the encapsulation of electronic components.

[0015] The advantages of this invention are as follows: 1. The provided potting compound composition is a single-component package, eliminating the need for on-site preparation and avoiding errors and material waste during the weighing and mixing of multi-component materials. This simplifies the construction process and is particularly suitable for automated production lines, significantly improving production efficiency and product consistency. 2. The surface effect is adjustable, especially achieving a matte finish. This invention synthesizes specific latent composite curing agents (curing agents A and B) and utilizes the activity differences of different reactive groups to control the microscopic uniform shrinkage of the potting compound surface during the curing process, thereby controlling the surface gloss. A uniform and stable matte surface can be obtained without additional treatment. Furthermore, by adjusting the type and ratio of curing agents, a semi-matte to high-gloss surface effect can be achieved, meeting the needs of different application scenarios. 3. Through reasonable raw material selection and process control, the potting compound composition of this invention exhibits good mechanical strength, electrical insulation properties, and chemical corrosion resistance after curing, providing effective protection for electronic components and demonstrating excellent overall performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the surface of a mildly cured matte epoxy resin composition, a comparative acid anhydride cured product, and a comparative amine cured product in one embodiment. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0018] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] like Figure 1 As shown, a medium-temperature curing matte epoxy resin composition is presented. The composition comprises epoxy resin and several excipients. The epoxy resin is in 100 parts by weight. The excipients include 10-15 parts by weight of diluent, 50-70 parts by weight of filler, 15-35 parts by weight of curing agent, and 3-8 parts by weight of additives. The finished product, a mixture of epoxy resin and excipients, is packaged as a single component, for example, in a 5kg drum. It can be used directly on-site without secondary mixing. After filling and sealing the electronic product, it is heated to 80-120 degrees Celsius for rapid curing.

[0021] Preferably, the epoxy resin is selected from bisphenol A type epoxy resin E51 and / or bisphenol A type epoxy resin E44, and the diluent is selected from epoxy diluent AGE (alkyl glycidyl ether) or 678 diluent.

[0022] Preferably, the curing agent comprises curing agent A and / or curing agent B prepared by the following method: curing agent A is prepared by mixing and melting 1.65 parts by weight of 2-ethyl-4-methylimidazolium, 0.25 parts by weight of diaminodiphenylmethane, 0.56 parts by weight of methyltetrahydrophthalic anhydride, 1.24 parts by weight of toluene diisocyanate and 2.4 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher; curing agent B is prepared by mixing and melting 1.65 parts by weight of diethylimidazolium, 1.01 parts by weight of triethylamine, 0.65 parts by weight of cyanuric chloride, 0.56 parts by weight of methyltetrahydrophthalic anhydride and 1.85 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher. In this design, when the unit of weight is used for measurement, the unit can be either gram or kilogram.

[0023] Preferably, the curing agent further includes at least one of organic hydrazide DICY or thiourea.

[0024] Preferably, the filler is selected from one or more of 325-mesh or 1250-mesh activated silica powder, wollastonite, and alumina; the additives include coupling agents, leveling agents, defoamers, dispersants, and pigments.

[0025] Preferably, the coupling agent is one or more of KH550, KH560, or titanate coupling agents; the pigment is one or more of phthalocyanine blue BGS color paste, phthalocyanine blue BS color paste, or rutile titanium dioxide.

[0026] Preferably, the auxiliary materials further include a flame retardant, which is a phosphorus-nitrogen composite flame retardant.

[0027] According to a particularly preferred embodiment, the bisphenol A type epoxy resin E51 is 100 parts by weight, the filler is selected from 325 mesh or 1250 mesh active silica powder, and the curing agent is 50 parts by weight; 15 parts by weight of curing agent and 3 parts by weight of additives, the additive being a dispersant. The curing agent is curing agent A. To prepare curing agent A, 1.65 kg of 2-ethyl-4-methylimidazolium, 0.25 kg of diaminodiphenylmethane, 0.56 kg of methyltetrahydrophthalic anhydride, 1.24 kg of toluene diisocyanate, and 2.4 kg of epoxy resin E51 are added to a reaction vessel. Heating is turned on to melt the materials, the reaction temperature is controlled at 140-160°C, and the reaction is stirred for 2 hours. After the reaction is completed, cooling yields a brownish-yellow brittle solid, which is pulverized and finely ground to 300 mesh to obtain curing agent A, which is then set aside.

[0028] According to a particularly preferred embodiment, the bisphenol A type epoxy resin E44 comprises 100 parts by weight, 60 parts by weight of wollastonite as filler, 20 parts by weight of curing agent, and 5 parts by weight of additives, the additive being a leveling agent. The curing agent is curing agent B. To prepare curing agent B, 1.65 kg of diethylimidazole, 1.01 kg of triethylamine, 0.65 kg of cyanuric chloride, 0.56 kg of methyltetrahydrophthalic anhydride, and 1.85 kg of epoxy resin E51 are added to a reaction vessel. The mixture is heated to melt and stirred at 140-160°C for 2 hours. After cooling, it is pulverized and finely ground to 300 mesh to obtain curing agent B, which is then set aside.

[0029] According to a particularly preferred embodiment, the bisphenol A type epoxy resin E51 is 100 parts by weight, wollastonite is selected as the filler (60 parts by weight), 20 parts by weight of curing agent, and 5 parts by weight of additives, the additives being pigments. The curing agent is curing agent A. To prepare curing agent A, 1.65 kg of 2-ethyl-4-methylimidazolium, 0.25 kg of diaminodiphenylmethane, 0.56 kg of methyltetrahydrophthalic anhydride, 1.24 kg of toluene diisocyanate, and 2.4 kg of epoxy resin E51 are added to a reaction vessel. Heating is initiated to melt the materials, and the reaction temperature is controlled at 140-160°C. The reaction is stirred for 2 hours. After the reaction is complete, cooling yields a brownish-yellow brittle solid, which is pulverized and finely ground to 300 mesh to obtain curing agent A, which is then set aside.

[0030] According to a particularly preferred embodiment, the bisphenol A type epoxy resin E44 comprises 100 parts by weight, with 70 parts by weight of alumina as filler, 25 parts by weight of curing agent, and 7 parts by weight of additives, the additive being an antifoaming agent. The curing agent is curing agent B. To prepare curing agent B, 1.65 kg of diethylimidazole, 1.01 kg of triethylamine, 0.65 kg of cyanuric chloride, 0.56 kg of methyltetrahydrophthalic anhydride, and 1.85 kg of epoxy resin E51 are added to a reaction vessel. The mixture is heated to melt and stirred at 140-160°C for 2 hours. After cooling, it is pulverized and finely ground to 300 mesh to obtain curing agent B, which is then set aside.

[0031] The preparation method of the medium-temperature curing matte epoxy resin composition involves first mixing the materials: weighing 100 parts by weight of epoxy resin (E51 and E44 mixed in a mass ratio of 3:1), 12 parts by weight of diluent AGE, adding 5 parts by weight of additives (including KH550 coupling agent, leveling agent, defoamer, and dispersant), 3 parts by weight of phthalocyanine blue BGS color paste, 2 parts by weight of phosphorus-nitrogen composite flame retardant, and 25 parts by weight of curing agent (composed of curing agent A from Example 1 and organic hydrazide DICY in a mass ratio of 4:1), and stirring until homogeneous. Grinding: adding 60 parts by weight of filler (325-mesh activated silica powder and wollastonite powder mixed in a mass ratio of 1:1) to the above mixture, transferring to a three-roll mill, and grinding three times until the material fineness reaches 500 mesh or more. Vacuum degassing: pouring the ground material into a vacuum mixing tank, starting the stirring (24 rpm), and simultaneously drawing a vacuum to -0.08 MPa, continuing degassing for 2.5 hours. Finished product: The product is discharged, which yields the medium-temperature curing matte epoxy resin potting compound composition of the present invention.

[0032] The performance tests of the epoxy resin compositions prepared by the above method are as follows: The potting compound composition prepared in Example 3 was cured at 80-100℃ for 2-4 hours. The performance of the cured samples was tested as follows: 1. Surface finish: Visually inspected, the surface exhibits a uniform matte texture with no reflective spots. 2. Mechanical properties: Flexural strength ≥ 105 MPa, impact strength ≥ 12 kJ / m². 3. Electrical insulation properties: Volume resistivity ≥ 1×10¹ 4 Ω·cm, dielectric strength ≥20 kV / mm. 4. Operational performance: As a single-component material, it has a shelf life of more than 6 months at room temperature.

[0033] To verify the beneficial effects of the present invention, the following comparative examples were set up: Comparative Example 1: A potting compound was prepared using a commercially available conventional acid anhydride curing agent (methyltetrahydrophthalic anhydride), epoxy resin E51, and the same filler. The surface after curing was high gloss.

[0034] Comparative Example 2: A potting compound was prepared using a commercially available conventional amine curing agent, epoxy resin E51, and the same filler. The surface was high-gloss after curing.

[0035] Test results show that the potting compound of Example 3 of the present invention can achieve a stable matte surface while meeting the requirements of electronic component packaging in terms of mechanical and electrical insulation properties. Moreover, the single-component method is simpler to operate and more stable in performance compared with the comparative ratio on-site mixing.

[0036] A method for preparing a medium-temperature curing matte epoxy resin composition, wherein the composition is prepared using the epoxy resin potting compound composition according to any one of claims 1-7 as raw material, and the preparation method includes the following steps. S1, Weigh the epoxy resin, diluent, curing agent and additives according to the weight parts, and stir them evenly to obtain a mixture; S2, add filler to the mixture and grind it on a three-roll mill until the fineness reaches 500 mesh or more; S3, the ground mixture is transferred to a vacuum mixing tank and vacuumed under stirring to remove air bubbles, thus obtaining the potting compound composition.

[0037] Preferably, in step S3, the stirring speed of the vacuum mixing tank is 24 rpm, the vacuum degree is -0.08 MPa, and the vacuuming time is 2-3 hours.

[0038] According to a particularly preferred embodiment, the present invention provides the application of a medium-temperature curing surface matte epoxy potting compound composition in the encapsulation of electronic components.

[0039] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A medium-temperature curing, matte epoxy resin composition, characterized in that: The composition comprises an epoxy resin and several excipients, wherein the epoxy resin is in the amount of 100 parts by weight, and the excipients include a diluent in the amount of 10-15 parts by weight, a filler in the amount of 50-70 parts by weight, a curing agent in the amount of 15-35 parts by weight, and an additive in the amount of 3-8 parts by weight.

2. The medium-temperature curing matte epoxy resin composition as described in claim 1, characterized in that: The epoxy resin is selected from bisphenol A type epoxy resin E51 and / or bisphenol A type epoxy resin E44, and the diluent is selected from epoxy diluent AGE (alkyl glycidyl ether) or 678 diluent.

3. The medium-temperature curing matte epoxy resin composition as described in claim 1, characterized in that: The curing agent comprises curing agent A and / or curing agent B prepared by the following methods: Curing agent A is prepared by mixing and melting 1.65 parts by weight of 2-ethyl-4-methylimidazolium, 0.25 parts by weight of diaminodiphenylmethane, 0.56 parts by weight of methyltetrahydrophthalic anhydride, 1.24 parts by weight of toluene diisocyanate and 2.4 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher; Curing agent B is prepared by mixing and melting 1.65 parts by weight of diethylimidazolium, 1.01 parts by weight of triethylamine, 0.65 parts by weight of cyanuric chloride, 0.56 parts by weight of methyltetrahydrophthalic anhydride and 1.85 parts by weight of epoxy resin E51, stirring and reacting at 140-160°C for 1.5-2.5 hours, cooling and then pulverizing to a fineness of 300 mesh or higher.

4. The medium-temperature curing matte epoxy resin composition as described in claim 1, characterized in that: The curing agent also includes at least one of organic hydrazide DICY or thiourea.

5. The medium-temperature curing matte epoxy resin composition as described in claim 1, characterized in that: The filler is selected from one or more of 325-mesh or 1250-mesh activated silica powder, wollastonite, and alumina; the additives include coupling agents, leveling agents, defoamers, dispersants, and pigments.

6. The medium-temperature curing matte epoxy resin composition as described in claim 5, characterized in that: The coupling agent is one or more of KH550, KH560, or titanate coupling agents; the pigment is one or more of phthalocyanine blue BGS color paste, phthalocyanine blue BS color paste, or rutile titanium dioxide.

7. The medium-temperature curing matte epoxy resin composition as described in claim 1, characterized in that: The auxiliary materials also include a flame retardant, which is a phosphorus-nitrogen composite flame retardant.

8. A method for preparing a medium-temperature curing matte epoxy resin composition, characterized in that: The composition is prepared using the epoxy resin potting compound composition according to any one of claims 1-7 as a raw material, and the preparation method includes the following steps. S1, Weigh the epoxy resin, diluent, curing agent and additives according to the weight parts, and stir them evenly to obtain a mixture; S2, add filler to the mixture and grind it on a three-roll mill until the fineness reaches 500 mesh or more; S3, the ground mixture is transferred to a vacuum mixing tank and vacuumed under stirring to remove air bubbles, thus obtaining the potting compound composition.

9. The preparation method according to claim 8, characterized in that: In step S3, the stirring speed of the vacuum stirring tank is 24 revolutions per minute, the vacuum degree is -0.08 MPa, and the vacuuming time is 2-3 hours.

10. The application of a medium-temperature curing matte epoxy resin potting compound composition as described in any one of claims 1-7 in the encapsulation of electronic components.

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