High-toughness low-dielectric bio-based benzoxazine resin, preparation method thereof and resin composition for copper-clad plate

Abstract

The preparation method comprises the following steps: adding bio-based amine, bio-based phenol and bio-based aldehyde into a reactor provided with a stirrer, a thermometer, a condenser pipe and a water segregator, adding toluene and a catalyst, uniformly stirring, heating, separating out water generated by a system by using the water segregator while heating, and adding a catalyst into the reactor to obtain the high-toughness low-dielectric bio-based benzoxazine resin. And when the temperature is raised to 120-140 DEG C, maintaining the reaction for 3-5 hours, washing and layering the obtained resin by using a 1mol / L NaOH solution, taking the lower resin layer, washing and layering by using deionized water, taking the lower resin layer, and removing methylbenzene and water by using a rotary evaporator to obtain the low-dielectric and high-toughness full-bio-based benzoxazine resin. The invention also relates to a resin composition for the copper-clad plate. The phenol source and the amine source of the high-toughness low-dielectric bio-based benzoxazine resin contain long carbon chains in chemical structures, the flexible carbon chains provide good ductility and toughness of the resin and increase the free volume of molecules, and the dielectric constant and dielectric loss of the resin are low.

Description

Technical Field

[0001] The present invention relates to the field of copper clad laminates, and specifically to a high-toughness and low-dielectric bio-based benzoxazine resin and its preparation method, and also to a resin composition for copper clad laminates. Background Art

[0002] In today's era when the problems of global warming and air pollution are becoming increasingly serious, climate change has become the focus of attention in all sectors of society. Bio-based resins use renewable resources such as plant oils, starches, and celluloses as raw materials. The carbon emissions during the production process are much lower than those of traditional petroleum-based resins, which can effectively reduce greenhouse gas emissions and reduce the carbon footprint in the industrial field.

[0003] Benzoxazine resin is a six-membered heterocyclic compound containing C, N, and O formed by the condensation of phenol, primary amine, and formaldehyde. Under the action of heat or a catalyst, it undergoes ring-opening polymerization to form a nitrogen-containing network structure similar to phenolic resin. The cured product has characteristics such as a low dielectric constant and dielectric loss, low water absorption, processing dimensional stability, and good flame retardancy, and is one of the suitable raw materials for preparing copper clad laminates. The synthesis raw materials of benzoxazine are usually phenol, bisphenol A, bisphenol F, aniline, diaminodiphenylmethane, diaminodiphenyl ether, paraformaldehyde, etc. These are basically all from petroleum cracking products, and the synthesized benzoxazine belongs to petroleum-based resin, which cannot meet the requirements of green development. Researchers have begun to develop bio-based benzoxazine resins. For example, in patent CN111057050A, phloretic acid and furfurylamine are used as the phenol source and amine source, and reacted with paraformaldehyde to produce a bio-based benzoxazine resin; in patent CN114195803A, dihydroxycoumarin, an amine compound, and paraformaldehyde are reacted to produce a coumarin-based bio-based bifunctional benzoxazine resin; in patent CN118562127A, bisphenolic acid ester is first synthesized by reacting bisphenolic acid with an alcohol, and then it is reacted with paraformaldehyde and bis(trifluoromethyl-diaminobiphenyl) to synthesize a bio-based benzoxazine resin with high Tg and intrinsic flame retardancy. In CN115260489A, a bio-based monophenol, a bio-based diamine (Priamine1074), and paraformaldehyde are used to synthesize a bio-based bifunctional benzoxazine resin. Similar patents also include CN113845638A, CN115260425A, etc. However, in such reports, only the phenol source and amine source use bio-based raw materials, but most of the aldehyde substances use paraformaldehyde, and paraformaldehyde still belongs to petroleum-based compounds. Therefore, such benzoxazine resins are not fully bio-based benzoxazine resins. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-toughness and low-dielectric bio-based benzoxazine resin and its preparation method, as well as a resin composition for copper clad laminates.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows: A high-toughness and low-dielectric bio-based benzoxazine resin, and its innovation lies in that the benzoxazine resin has a chemical structural general formula shown in formula (1) or formula (2): In formula (1): R1 is -C 15 H 29 or -C 11 H 20 NO, R2 is -OCH3 or -H, R3 is -C 18 H 37 or -C 12 H 25 ; In formula (2): R4 is -C 15 H 29 or -C 11 H 20 NO, R5 is -OCH3 or -H, R6 is -C4H8, -C5H 10 、-C6H 12 or -C 10 H 20 any one of them.

[0006] A preparation method of the above high-toughness and low-dielectric bio-based benzoxazine resin, and its innovation lies in that it includes the following steps: First, take a reactor, and install a stirrer, a thermometer, a condenser and a water separator in the reactor; Then, add bio-based amine, bio-based phenol and bio-based aldehyde with a molar ratio of 1:1.1 - 1.5:2.5 - 3 to the reactor, and then add toluene with a weight 1 - 3 times the total mass of the mixture in the reactor and a catalyst with a weight of 1‰ - 1% of the total weight of the materials, stir evenly and then heat up, and use the water separator to separate the water generated in the system while heating up. When the temperature rises to 120 - 140 °C, maintain the reaction for 3 - 5 h to obtain a resin mixture; Finally, wash the obtained resin mixture with 1 mol / L NaOH solution, layer it, and take out the lower resin layer after layering. Then wash the lower resin layer with deionized water for secondary washing and layering, also take out the lower resin layer after secondary layering, and then use a rotary evaporator to remove toluene and water in the lower resin layer after secondary layering, and thus obtain the required high-toughness and low-dielectric bio-based benzoxazine resin.

[0007] Further, the bio-based phenol is any one or a mixture of two of cardanol and capsaicin; the bio-based amine is any one or a mixture of several of butanediamine, pentanediamine, hexanediamine, decanediamine, laurylamine, and octadecylamine; the bio-based aldehyde is benzaldehyde; and the catalyst is any one or a mixture of several of zinc chloride, indium trihalide, ferric trichloride, antimony pentachloride, trifluoromethanesulfonate, morpholine trifluoroacetate, and sodium hydroxide.

[0008] A resin composition for a copper clad laminate, the innovation of which lies in: the resin composition for a copper clad laminate is prepared by uniformly mixing 50 parts by mass of DCPD epoxy resin, 20 - 30 parts by mass of the above-mentioned high-toughness and low-dielectric bio-based benzoxazine resin, 10 - 20 parts by mass of maleimide resin, 0.1 - 0.5 parts by mass of an imidazole catalyst, 60 - 80 parts by mass of a filler, and 60 - 100 parts by mass of a solvent at 30 - 50 °C.

[0009] Further, the solid content of the resin composition for a copper clad laminate is 58% - 75%.

[0010] Further, the DCPD epoxy resin has the chemical structural formula shown in Formula (3): The maleimide resin has the general chemical structural formula shown in Formula (4): In Formula (4): R7 and R8 are any one of -H, -CH3, and -C2H5; The imidazole catalyst is any one or a mixture of two or more of imidazole, 2-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, 1,3-dimethylimidazole, and 2,4-dimethylimidazole; The filler is any one or a mixture of two or more of montmorillonite, calcium carbonate, magnesium hydroxide, zinc borate, talc, aluminum hydroxide, kaolin, barium sulfate, silica, silica powder, mica powder, hollow glass microspheres, and fumed silica; The solvent is any one or a mixture of two or more of methyl ethyl ketone, toluene, xylene, cyclohexanone, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide, and methyl isobutyl ketone.

[0011] The advantages of the present invention are as follows: for the high-toughness and low-dielectric bio-based benzoxazine resin of the present invention, a bio-based phenol, a bio-based amine, and a bio-based aldehyde are used for reaction, and all the raw materials participating in the reaction are bio-based raw materials, and the synthesized benzoxazine resin is a fully bio-based benzoxazine resin.

[0012] The phenol source and amine source of the high-toughness and low-dielectric bio-based benzoxazine resin of the present invention both contain relatively long carbon chains in their chemical structures. The flexible carbon chains not only provide the resin with good ductility and toughness, but also increase the molecular free volume, resulting in lower dielectric constant and dielectric loss of the resin.

[0013] In the resin composition for copper clad laminates of the present invention, DCPD epoxy resin with good dielectric properties is introduced. Because its structure contains a non-polar dicyclopentadiene skeleton, the molecular free volume is increased, further reducing the dielectric constant and dielectric loss of the product.

[0014] In a resin composition for copper clad laminates of the present invention, maleimide resin with good structural symmetry and rigidity is introduced, further reducing the dielectric constant and dielectric loss of the product; at the same time, due to the introduction of a highly heat-resistant imide ring, the heat resistance of the product is further improved.

[0015] For the resin composition for copper clad laminates of the present invention, after pressing: Tg≥190°C, Td5%≥350°C; dielectric constant≤3.3 (10 GHz); dielectric loss≤0.008 (10 GHz); flexural strength≥550 MPa. It has the characteristics of high toughness, low dielectric constant, and low dielectric loss.

[0016] The high-toughness and low-dielectric bio-based benzoxazine resin of the present invention can replace the existing petroleum-based benzoxazine resin for the preparation of resin compositions for high-performance copper clad laminates. Detailed implementation mode

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in combination with preferred embodiments, describe in detail the specific implementation mode, structure, characteristics and effects according to the present invention as follows.

[0018] The high-toughness and low-dielectric bio-based benzoxazine resin of the present invention has the general chemical structure formula shown in formula (1) or formula (2): In formula (1): R1 is -C 15 H 29 or -C 11 H 20 NO, R2 is -OCH3 or -H, R3 is -C 18 H 37 or -C 12 H 25 .

[0019] In formula (2): R4 is -C 15 H 29 or -C 11 H 20NO, R5 is -OCH3 or -H, and R6 is -C4H8, -C5H 10 , -C6H 12 or -C 10 H 20 any one of them.

[0020] The above-mentioned high-toughness and low-dielectric bio-based benzoxazine resin is prepared through the following steps: First, take a reactor, and install a stirrer, a thermometer, a condenser and a water separator in the reactor.

[0021] Then, add bio-based amine (calculated according to the amount of amino group), bio-based phenol and bio-based aldehyde with a molar ratio of 1:1.1 - 1.5:2.5 - 3 into the reactor. Among them, the bio-based phenol is any one or a mixture of two of cardanol and capsaicin, the bio-based amine is any one or a mixture of several of butanediamine, pentanediamine, hexanediamine, decanediamine, laurylamine, octadecylamine, and the bio-based aldehyde is benzaldehyde.

[0022] Then add toluene with a weight 1 - 3 times that of the total mass of the mixture in the reactor and a catalyst with a weight of 1‰ - 1% of the total weight of the materials. The catalyst is any one or a mixture of several of zinc chloride, indium trihalide, ferric trichloride, antimony pentachloride, trifluoromethanesulfonate, morpholine trifluoroacetate, sodium hydroxide. After stirring evenly, heat up, and use the water separator to separate the water generated in the system while heating up. When the temperature rises to 120 - 140 °C, maintain the reaction for 3 - 5 h to obtain a resin mixture.

[0023] Finally, wash the obtained resin mixture with 1 mol / L NaOH solution, layer it, and take out the lower resin layer after layering. Then wash the lower resin layer with deionized water for secondary washing and layering, and also take out the lower resin layer after secondary layering. Then use a rotary evaporator to remove toluene and water in the lower resin layer after secondary layering, and the required high-toughness and low-dielectric bio-based benzoxazine resin is obtained.

[0024] Table 1 is a table of the raw material dosage (unit: g), process parameters and technical performance of the high-toughness and low-dielectric bio-based benzoxazine resin prepared by the above preparation method: In Table 1, the high-toughness and low-dielectric bio-based benzoxazine resin prepared in Examples 1-1 to 1-4 was cured according to the program of 140 °C for 1 h, 160 °C for 1 h, 180 °C for 1 h, 200 °C for 2 h to make a casting body of 50 mm × 50 mm × 0.8 mm, and Dk / Df was tested.

[0025] The resin composition for copper clad laminates is prepared by using the high-toughness, low-dielectric bio-based benzoxazine resin. The resin composition for copper clad laminates is prepared by mixing and stirring 50 parts by mass of DCPD epoxy resin, 20 to 30 parts by mass of the high-toughness, low-dielectric bio-based benzoxazine resin, 10 to 20 parts by mass of maleimide resin, 0.1 to 0.5 parts by mass of imidazole catalyst, 60 to 80 parts by mass of filler and 60 to 100 parts by mass of solvent at 30 to 50°C.

[0026] The solid content of the resin composition for copper clad laminate is 58% to 75%, and the solid content is defined as the weight percentage of the solid content in the solution to the total solution.

[0027] DCPD epoxy resin has the chemical structure shown in formula (3): Specifically, the DCPD epoxy resin is selected from one of DFE228 and DFE228H of Sichuan Dongcai Technology Group Co., Ltd., or a mixture of two of them.

[0028] Maleimide resin has the general chemical structure shown in formula (4): In formula (4), R7 and R8 are any one of -H, -CH3 and -C2H5.

[0029] Specifically, the maleimide resin is selected from one of DFE930, DFE936, and DFE939 of Sichuan Dongcai Technology Group Co., Ltd., or a mixture of two or more thereof.

[0030] The imidazole catalyst is any one of imidazole, 2-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, 1,3-dimethylimidazole, and 2,4-dimethylimidazole, or a mixture of two or more thereof.

[0031] The filler is any one of montmorillonite, calcium carbonate, magnesium hydroxide, zinc borate, talc, aluminum hydroxide, kaolin, barium sulfate, silicon dioxide, silicon micropowder, mica powder, hollow glass microspheres, and fumed silica, or a mixture of two or more thereof.

[0032] The solvent is any one of butanone, toluene, xylene, cyclohexanone, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide, and methyl isobutyl ketone, or a mixture of two or more thereof.

[0033] Table 2 is a table of the dosage of the formula raw materials of the resin composition for copper-clad laminates of Examples 2-1 to 2-4 (unit: g): The above resin composition for copper clad laminates is used to prepare prepregs and copper clad laminates: Preparation of prepregs: Select E-glass cloth that is flat, smooth, and 0.2 mm thick. Immerse it in the above resin composition (solution) for copper clad laminates, then take it out and bake it in an oven at 130 - 170 °C for 4 - 7 minutes to obtain the required prepregs. The resin weight percentage content of the prepared prepregs is 62% - 68%.

[0034] Preparation of copper clad laminates: Cut and stack the above prepregs, cover copper foil on both sides or one side of the prepregs, then place them in a hot press. Keep the heating rate at 1 - 3 °C / min. After reaching the temperature, press at a pressure of 0.2 - 1 MPa and a temperature of 80 - 150 °C for 1 - 3 hours, then continue to heat up, keep the heating rate at 1 - 3 °C / min. After reaching the temperature, press at a pressure of 0.2 - 3 MPa and a temperature of 150 - 250 °C for 1 - 4 hours to form. The resin content (RC) of the board is 60 ± 2%.

[0035] The technical performance of the copper clad laminates prepared by the above method is shown in Table 3: The technical performance test methods in Tables 2 and 3 are as follows: (1) Dielectric constant According to IPC-TM-650, the dielectric constant at 10 GHz is measured using the planar method in 2.5.5.9.

[0036] (2) Dielectric loss According to IPC-TM-650, the tangent of the loss factor angle of the dielectric at 10 GHz is measured using the planar method in 2.5.5.9.

[0037] (3) Glass transition temperature (Tg) It is measured according to the differential scanning calorimetry method and the DSC method specified in IPC-TM-650 2.4.25.

[0038] (4) Thermal decomposition temperature (Td) It is measured according to the method specified in IPC-TM-650 2.4.26.

[0039] Flexural strength It is measured according to the method specified in the test standard for electrical insulating material laminates GB / T 5130 - 1997.

[0040] As can be seen from Table 3, the sheet materials obtained by applying the embodiments of the present invention have excellent toughness, low dielectric constant and dielectric loss factor, and high heat resistance. The resin composition for copper clad laminate of the present invention can be used in the fields of laminates, integrated circuit packages, high-frequency and high-speed copper clad laminates, high-density Internet, artificial intelligence, etc., and has broad application prospects.

[0041] In the above embodiments: among the percentage ratios used, unless otherwise specified, they are all mass (weight) percentage ratios or percentage ratios well-known to those skilled in the art; among the ratios used, unless otherwise specified, they are all mass (weight) ratios; the parts by weight can all be grams or kilograms.

[0042] In the above embodiments: for the process parameters (temperature, time, pressure, etc.) and the numerical values of the amounts of each component in each step that are in a range, any point can be applicable.

[0043] The technical content not specifically described in the content of the present invention and the above embodiments is the same as the prior art, and all the raw materials are commercially available products.

[0044] The high-toughness and low-dielectric bio-based benzoxazine resin of the present invention is prepared by reacting bio-based phenols (cardanol is derived from natural cashew nut shell oil; capsaicin is synthesized from vanillin extracted from the vanilla bean of the orchid family and branched-chain fatty acids), bio-based amines (1,4-diaminobutane, also known as putrescine, obtained by enzymatic conversion; 1,5-diaminopentane is derived from vegetable oil or polysaccharide; 1,6-diaminohexane is extracted from waste cooking oil; 1,10-diaminodecane is derived from castor oil; laurylamine is prepared from lauric acid; stearylamine is obtained by ammoniation and hydrogenation of stearic acid) with bio-based aldehydes (benzaldehyde comes from hyacinth, citronella, cinnamon, iris, rockrose). All the raw materials participating in the reaction are bio-based raw materials, and the synthesized benzoxazine resin is a fully bio-based benzoxazine resin.

[0045] The phenol source and amine source of the high-toughness and low-dielectric bio-based benzoxazine resin of the present invention both contain relatively long carbon chains in their chemical structures. The flexible carbon chains not only provide good ductility and toughness for the resin, but also increase the molecular free volume, and the dielectric constant (Dk) and dielectric loss (Df) of the resin are relatively low. (Dielectric constant ≤ 2.8 (10 GHz); Dielectric loss ≤ 0.008 (10 GHz)).

[0046] DCPD epoxy resin with good dielectric properties is introduced into the resin composition for copper clad laminate of the present invention. Because its structure contains a non-polar dicyclopentadiene skeleton, it increases the molecular free volume, further reducing the dielectric constant and dielectric loss of the product.

[0047] Maleimide resin with good structural symmetry and rigidity is introduced into the resin composition for copper clad laminate of the present invention, further reducing the dielectric constant and dielectric loss of the product; at the same time, due to the introduction of a highly heat-resistant imide ring, the heat resistance of the product is further improved.

[0048] The resin composition for copper clad laminate of the present invention, after pressing: Tg ≥ 190 °C, Td5% ≥ 350 °C; dielectric constant ≤ 3.3 (10 GHz); dielectric loss ≤ 0.008 (10 GHz); flexural strength ≥ 550 MPa, and it has the characteristics of high toughness, low dielectric constant, low dielectric loss, etc.

[0049] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A high-toughness and low-dielectric bio-based benzoxazine resin, characterized in that: The benzoxazine resin has a general chemical structure formula shown in formula (1) or formula (2): In formula (1): R1 is -C 15 H 29 or -C 11 H 20 NO, R2 is -OCH3 or -H, R3 is -C 18 H 37 or -C 12 H 25 ; In formula (2): R4 is -C 15 H 29 or -C 11 H 20 NO, R5 is -OCH3 or -H, and R6 is -C4H8, -C5H 10 , -C6H 12 or -C 10 H 20 any one of them.

2. The preparation method of the high-toughness and low-dielectric bio-based benzoxazine resin according to claim 1, characterized in that: It includes the following steps: First, take a reactor, in which a stirrer, a thermometer, a condenser and a water separator are installed; Then, add bio-based amine, bio-based phenol and bio-based aldehyde with a molar ratio of 1:1.1 - 1.5:2.5 - 3 into the reactor, and then add toluene with a weight 1 - 3 times that of the total mass of the mixture in the reactor and a catalyst with a weight of 1‰ - 1% of the total weight of the materials. After stirring evenly, heat up, and while heating, use the water separator to separate the water generated in the system. When the temperature rises to 120 - 140 °C, maintain the reaction for 3 - 5 h to obtain a resin mixture; Finally, wash the obtained resin mixture with 1 mol / L NaOH solution, layer it, and take out the lower resin layer after layering. Then, wash the lower resin layer with deionized water for secondary washing and layering, and also take out the lower resin layer after secondary layering. Then, use a rotary evaporator to remove toluene and water in the lower resin layer after secondary layering, and the required high-toughness and low-dielectric bio-based benzoxazine resin is obtained.

3. The high-toughness and low-dielectric bio-based benzoxazine resin according to claim 2, wherein: The bio-based phenol is any one or a mixture of two of cardanol and capsaicin; the bio-based amine is any one or a mixture of several of butanediamine, pentanediamine, hexanediamine, sebac diamine, laurylamine, stearylamine; the bio-based aldehyde is benzaldehyde; the catalyst is any one or a mixture of several of zinc chloride, indium trihalide, ferric trichloride, antimony pentachloride, trifluoromethanesulfonate, morpholine trifluoroacetate, sodium hydroxide.

4. A resin composition for a copper clad laminate, characterized in that: The resin composition for copper clad laminate is prepared by uniformly mixing 50 parts by mass of DCPD epoxy resin, 20 - 30 parts by mass of the high-toughness and low-dielectric bio-based benzoxazine resin described in claim 1, 10 - 20 parts by mass of maleimide resin, 0.1 - 0.5 parts by mass of imidazole catalyst, 60 - 80 parts by mass of filler and 60 - 100 parts by mass of solvent at 30 - 50 °C.

5. The resin composition for a copper clad laminate according to claim 4, wherein: The solid content of the resin composition for copper clad laminate is 58% - 75%.

6. The resin composition for a copper clad laminate according to claim 4, wherein: The DCPD epoxy resin has a chemical structural formula shown in formula (3): The maleimide resin has a general chemical structure formula shown in formula (4): In formula (4): R7, R8 are any one of -H, -CH3, -C2H5; The imidazole catalyst is any one or a mixture of two or more of imidazole, 2-methylimidazole, 1-methylimidazole, 1,2-dimethylimidazole, 1,3-dimethylimidazole, 2,4-dimethylimidazole; The filler is any one or a mixture of two or more of montmorillonite, calcium carbonate, magnesium hydroxide, zinc borate, talc, aluminum hydroxide, kaolin, barium sulfate, silica, silica powder, mica powder, hollow glass microspheres, fumed silica; The solvent is any one or a mixture of two or more of butanone, toluene, xylene, cyclohexanone, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, N,N-dimethylformamide, N,N-dimethylacetamide, methyl isobutyl ketone.

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