Super-heat-resistant resin composition, prepreg and laminated board

Abstract

The invention discloses a super heat-resistant resin composition, which is prepared from the following ingredients in parts by weight: 10 to 80 parts of bismaleimide, 5 to 50 parts of phthalonitrile compounds and 10 to 60 parts of epoxy resin. The diphenylsulfone bismaleimide is selected for preparing the resin composition, sulfonyl of the diphenylsulfone bismaleimide contains two-sulfur-oxygen double bonds, and the bond energy of sulfur-oxygen double bonds is very high, so that the molecular structure is very difficult to damage in a high-temperature environment, the high-temperature resistance of the resin composition is greatly improved, and meanwhile, the diphenylsulfone bismaleimide has a plurality of benzene ring structures, so that the high-temperature resistance of the resin composition is greatly improved. The diphenylsulfone bismaleimide is added into the resin composition, so that the rigidity is relatively strong, the thermal stability of the resin composition is improved, the heat resistance of the resin composition is further improved, and the diphenylsulfone bismaleimide is high in symmetry, so that a high-density cross-linked network is easier to form, and the heat resistance of the resin composition is further improved. And the phthalonitrile and phthalonitrile compound with better heat resistance is added into the resin system, so that the heat resistance of the resin composition is further improved.

Description

Technical Field

[0001] This invention relates to the field of resin compositions, and in particular to an ultra-heat resistant resin composition, a prepreg, and a laminate. Background Technology

[0002] In recent years, with the rapid development of mobile Internet technology, printed circuit boards for high-temperature sensors, high-power modules for new energy have placed higher demands on printed circuit board substrates. In addition to requiring them to have high peel strength and excellent low coefficient of thermal expansion, they also need to have ultra-high temperature resistance.

[0003] Bismaleimide possesses a high glass transition temperature and, compared to epoxy resins, exhibits higher crosslinking density and rigid molecular chain characteristics. Its cured product has a higher decomposition temperature and can be used for extended periods within a temperature range of 150-220℃. This overcomes the shortcomings of epoxy resins in terms of heat resistance while maintaining high strength, high modulus, solvent resistance, and chemical corrosion resistance, making it widely used in the circuit board industry. However, although conventional bismaleimide possesses high heat resistance, it does not withstand temperatures above 350℃. Conventional bismaleimide begins to decompose near 300℃, resulting in insufficient heat resistance in circuit boards and limiting their application. Therefore, it is necessary to propose a new solution to address these issues. Summary of the Invention

[0004] In view of this, the present invention addresses the deficiencies of the prior art, and its main objective is to provide an ultra-heat resistant resin composition, a prepreg, and a laminate, which can effectively solve the problem that conventional bismaleimide cannot withstand high temperatures above 350°C, resulting in insufficient heat resistance of the circuit boards made from it, thus limiting the application of the circuit boards.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A superheat-resistant resin composition, by weight, comprises the following components: 10-80 parts of bismaleimide, 5-50 parts of phthalonitrile compound, and 10-60 parts of epoxy resin; wherein the structural formula of the bismaleimide is as follows:

[0007] R1 in the formula is

[0008] As a preferred embodiment, the phthalonitrile compound is

[0009]

[0010] As a preferred embodiment, the epoxy resin is one or a combination of two or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, phosphorus-containing epoxy resin, nitrogen-containing epoxy resin, o-cresol aldehyde epoxy resin, bisphenol A phenolic epoxy resin, phenolic epoxy resin, cresol phenolic epoxy resin, triphenylmethane epoxy resin, tetraphenylethane epoxy resin, biphenyl type epoxy resin, naphthyl ring type epoxy resin, dicyclopentadiene type epoxy resin, isocyanate type epoxy resin, aralkyl linear phenolic epoxy resin, alicyclic epoxy resin, glycidyl amine type epoxy resin, glycidyl ether type epoxy resin, and glycidyl ester type epoxy resin.

[0011] As a preferred embodiment, it further includes 1-30 parts of a curing aid.

[0012] A semi-cured sheet is prepared by dissolving the aforementioned ultra-heat resistant resin composition in a solvent to obtain an adhesive solution, then impregnating a reinforcing material in the adhesive solution to obtain an impregnated reinforcing material, and finally heating and drying the impregnated reinforcing material to obtain a semi-cured sheet.

[0013] As a preferred embodiment, the reinforcing material is E-glass fiber cloth (2116).

[0014] A type of laminate is obtained by taking the aforementioned prepreg, placing a copper foil on each of its upper and lower surfaces, and then placing it in a vacuum hot press and pressing it.

[0015] As a preferred embodiment, the thickness of the copper foil is 18 μm, the pressing pressure is 1.5 MPa, the pressing temperature is 260 °C, and the pressing time is 4 h.

[0016] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution:

[0017] By selecting bismaleimide with a specific structure to prepare the resin composition, the bismaleimide being a diphenyl sulfone type bismaleimide, which has a sulfone group containing two sulfur-oxygen double bonds, the bond energy of which is very high, making the molecular structure extremely difficult to be destroyed under high temperature conditions, thereby greatly improving the high temperature resistance of the resin composition. At the same time, it has multiple benzene ring structures, making it more rigid and improving the thermal stability of the resin composition, thereby improving the heat resistance of the resin composition. Furthermore, the diphenyl sulfone type bismaleimide has high symmetry, making it easier to form a high-density cross-linked network, thereby improving the heat resistance of the resin composition. In addition, the addition of phthalonitrile compounds with better heat resistance to the resin system, which do not exhibit tanδ at 450℃ and have outstanding flame retardant properties with a limiting oxygen index greater than 70%, can further improve the heat resistance of the resin composition.

[0018] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to several specific embodiments. Detailed Implementation

[0019] This invention discloses an ultra-heat resistant resin composition, which, by weight, comprises the following components: 10-80 parts of bismaleimide, 5-50 parts of phthalonitrile compounds, 10-60 parts of epoxy resin, and 1-30 parts of curing aid.

[0020] The structural formula of the bismaleimide is as follows:

[0021] R1 in the formula is

[0022] Specifically, the phthalonitrile compounds are

[0023] The epoxy resin is one or a combination of two or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, phosphorus-containing epoxy resin, nitrogen-containing epoxy resin, o-cresol epoxy resin, bisphenol A phenolic epoxy resin, phenolic epoxy resin, cresol phenolic epoxy resin, triphenylmethane epoxy resin, tetraphenylethane epoxy resin, biphenyl type epoxy resin, naphthalene ring type epoxy resin, dicyclopentadiene type epoxy resin, isocyanate type epoxy resin, aralkyl linear phenolic epoxy resin, alicyclic epoxy resin, glycidylamine type epoxy resin, glycidyl ether type epoxy resin, and glycidyl ester type epoxy resin.

[0024] The present invention also discloses a semi-cured sheet, wherein the aforementioned super heat-resistant resin composition is dissolved in a solvent to obtain a filtrate, and then a reinforcing material is impregnated in the filtrate to obtain an impregnated reinforcing material. Then, the impregnated reinforcing material is heated and dried to obtain a semi-cured sheet; wherein the reinforcing material is E-glass fiber cloth (2116).

[0025] The present invention also discloses a laminate, wherein a copper foil is placed on each of the above-mentioned prepreg surfaces and placed in a vacuum hot press to obtain the laminate after pressing; the thickness of the copper foil is 18μm, the pressing pressure is 1.5MPa, the pressing temperature is 260℃, and the pressing time is 4h.

[0026] The following description is based on specific embodiments.

[0027] The raw materials used in the following examples and comparative examples are shown in Table 1.

[0028]

[0029] Table 1

[0030] The preparation method of phthalonitrile compound 1 is as follows:

[0031] Resorcinol, 4-nitrophthalonitrile, and anhydrous potassium carbonate were placed in a reaction vessel at a ratio of 1:0.5:1.2. DMF solvent was then added to the reaction vessel, and the reaction was carried out under an inert gas atmosphere (nitrogen gas) with mechanical stirring using a magnetic stirrer throughout the reaction. The reaction time was 24 hours. After the reaction, the resulting mixture was poured into an aqueous hydrochloric acid solution and repeatedly washed until the mixture became neutral, yielding a washing product. This washing product was then placed in a vacuum environment and dried at 80°C for 12 hours to obtain a pale yellow material, which is phthalonitrile compound 1. The reaction process is shown below:

[0032]

[0033] The preparation method of phthalonitrile compound 2 is as follows:

[0034] Resorcinol, 4-nitrophthalonitrile, and anhydrous potassium carbonate were placed in a reaction vessel in a ratio of 1.2:2:3. DMF solvent was then added to the reaction vessel, and the reaction was carried out under an inert gas atmosphere (nitrogen gas) with mechanical stirring using a magnetic stirrer throughout the reaction. The reaction time was 24 hours. After the reaction, the resulting mixture was cooled to room temperature and then poured into cold water for repeated washing until the mixture became neutral, yielding a washing product. This washing product was then placed in a vacuum environment and dried at 80°C for 22 hours to obtain a pale yellow material, which is phthalonitrile compound 2. The reaction process is shown below:

[0035]

[0036] The above-mentioned phthalonitrile compound 1 and phthalonitrile compound 2 were respectively reacted with diphenyl sulfone type bismaleimide, epoxy resin, and various reaction aids to prepare resin compositions.

[0037] The component ratios of Examples 1-3 and Comparative Examples 1-6 by weight are shown in Table 2:

[0038] Ingredients Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Phthalonitrile compound 1 40 40 Phthalonitrile compound 2 40 20 40 BMI 4000 40 30 30 BMI 12000 40 BMI 17000 40 40 Diphenyl sulfone type bismaleimide 30 30 50 30 30 30 NC 7000L 10 10 10 10 10 10 40 10 10 D C P]]> 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 2E4MZ 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 SC 2050-KC 203 203 203 203 203 203 203 203 203 DDS 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5

[0039] Table 2

[0040] For the preparation of semi-cured sheets in the above-mentioned embodiments and comparative examples, a semi-cured sheet is prepared by adding fillers and catalysts to the resin compositions obtained in the above-mentioned embodiments and comparative examples, dissolving them in an appropriate amount of butanone solvent, stirring and mixing evenly to obtain a slurry with a solid content of 65%. E-glass fiber cloth (2116) is then immersed in the slurry. After immersion, the E-glass fiber cloth (2116) is removed, and the slurry is coated onto the E-glass fiber cloth (2116). Subsequently, it is baked in an oven at 160°C for 5 minutes to obtain a semi-cured sheet. The aforementioned semi-cured sheet is then placed on its upper and lower surfaces with a copper foil and placed in a vacuum hot press. After pressing, a laminate is obtained. The thickness of the copper foil is 18 μm, the pressing pressure is 1.5 MPa, the pressing temperature is 260°C, and the pressing time is 4 hours.

[0041] The obtained laminates were subjected to performance tests, and the test methods are as follows.

[0042] Peel strength: Using a peel strength tester, three samples were tested according to the IPC-TM-650-2.4.8 method, and the average value was calculated.

[0043] Coefficient of thermal expansion: Tested using a TMA instrument according to the TMA test method specified in IPC-TM-650 2.4.24, with a range of 30℃-120℃.

[0044] Water absorption rate: Take three 10cm×10cm samples with a thickness of 0.80mm and metal foil removed from both sides. Dry them at 120℃ for 2 hours, then treat them in a pressure cooker at 121℃ and 2 atmospheres for 7 hours. After absorbing the free water on the surface, place them in a desiccator to cool and weigh them. Calculate the water absorption rate of the board based on the weight before and after.

[0045] Glass transition temperature (Tg): The dynamic mechanical property tester (TA DMA Q800, USA) was used, with a heating rate of 10℃ / min and a nitrogen atmosphere.

[0046] Thermal decomposition temperature: The sample was treated at 110℃ for 24 hours, then cooled to room temperature in a desiccator. The sample was then placed in a TGA testing instrument and heated from room temperature to 550℃ at a rate of 10℃ / min. The scanning curves were analyzed to determine the decomposition temperatures at mass losses of 1%, 3%, and 5%.

[0047] The test results are shown in Table 3.

[0048] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Thermal decomposition temperature (°C) 642 652 618 440 445 443 390 462 465 Glass transition temperature (°C) 460 393 396 285 297 283 267 310 312 Peeling strength (N / mm) 0.64 0.77 0.82 0.63 0.52 0.65 0.67 0.65 0.68 Water absorption rate (%) 0.32 0.35 0.33 0.52 0.53 0.52 0.61 0.55 0.54 X / Y axis CTE (ppm / °C) 2 3 5 8 7 8 10 8 7

[0049] Table 3

[0050] Analysis of the above data shows that the laminates prepared using the formulation of this invention have very high thermal decomposition and glass transition temperatures, with the highest thermal decomposition temperature reaching 652°C and the highest glass transition temperature reaching 460°C. Comparing Examples 1 and 2 with Comparative Examples 1-3, the difference lies in that Comparative Examples 1-3 use conventional bismaleimide instead of the phthalonitrile compounds in this invention. Examples 1 and 2 have thermal decomposition temperatures more than 200°C higher than Comparative Examples 1-3, and glass transition temperatures more than 100°C higher. This demonstrates that the phthalonitrile compounds in this invention play a crucial role in improving the heat resistance of the laminates. Furthermore, Comparative Example 4, which uses a conventional blend of bismaleimide and epoxy resin (a common design on the market), has the worst decomposition and glass transition temperatures among the various examples and comparative examples, indicating insufficient heat resistance. Insufficient to meet higher heat resistance requirements; furthermore, Examples 1 and 2 are compared with Comparative Examples 5 and 6 respectively. The difference is that Comparative Examples 5 and 6 use conventional bismaleimide combined with the phthalonitrile compound of this invention. The laminates obtained by these examples are significantly better than the other comparative examples in terms of thermal decomposition temperature and glass transition temperature. This is due to the improvement in heat resistance brought by the phthalonitrile compound of this invention in the resin system. However, compared with Examples 1 and 2, their thermal decomposition temperature and glass transition temperature are still worse. The thermal decomposition temperature of Examples 1 and 2 is more than 180°C higher than that of Comparative Examples 5 and 6, and the glass transition temperature of Examples 1 and 2 is more than 100°C higher than that of Comparative Examples 5 and 6. Therefore, it can be concluded that the phthalonitrile compound of this invention combined with diphenyl sulfone type bismaleimide can produce synergistic benefits, achieving a 1+1>2 effect and obtaining superior performance.

[0051] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A superheat-resistant resin composition, characterized in that: By weight, it comprises the following components: 10-80 parts of bismaleimide, 5-50 parts of phthalonitrile compound, and 10-60 parts of epoxy resin; wherein, the structural formula of the bismaleimide is as follows: R1 in the formula is 2. The superheat-resistant resin composition according to claim 1, characterized in that: The phthalonitrile compound is 3. The superheat-resistant resin composition according to claim 1, characterized in that: The epoxy resin is one or a combination of two or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, phosphorus-containing epoxy resin, nitrogen-containing epoxy resin, o-cresol epoxy resin, bisphenol A phenolic epoxy resin, phenolic epoxy resin, cresol phenolic epoxy resin, triphenylmethane epoxy resin, tetraphenylethane epoxy resin, biphenyl type epoxy resin, naphthalene ring type epoxy resin, dicyclopentadiene type epoxy resin, isocyanate type epoxy resin, aralkyl linear phenolic epoxy resin, alicyclic epoxy resin, glycidylamine type epoxy resin, glycidyl ether type epoxy resin, and glycidyl ester type epoxy resin.

4. The superheat-resistant resin composition according to claim 1, characterized in that: The further component includes 1-30 parts of a curing aid.

5. A semi-cured sheet, characterized in that: The super heat-resistant resin composition according to any one of claims 1-4 is dissolved in a solvent to obtain a glue solution. The reinforcing material is then impregnated in the glue solution to obtain the impregnated reinforcing material. The impregnated reinforcing material is then heated and dried to obtain a semi-cured sheet.

6. The prepreg according to claim 5, characterized in that: The reinforcing material is E-glass fiber cloth (2116).

7. A laminate, characterized in that: Take the semi-cured sheet as described in claim 5, place a metal copper foil on each of its upper and lower surfaces, and place it in a vacuum hot press. After pressing, a laminate is obtained.

8. The laminate according to claim 7, characterized in that: The copper foil has a thickness of 18 μm, a pressing pressure of 1.5 MPa, a pressing temperature of 260 °C, and a pressing time of 4 h.

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