Flexible c-si crosslinking resin, and preparation method and application thereof

Abstract

The application discloses a flexible C-Si crosslinking resin and a preparation method and application thereof. A multi-functionality silicon hydride compound and a multi-functionality carbon-carbon double bond compound are subjected to a silicon hydrogen addition reaction to obtain a macromolecular crosslinking agent containing a silicon hydrogen group at the end, the obtained macromolecular crosslinking agent and a carbon hydrogen resin containing a carbon-carbon unsaturated bond are subjected to a silicon hydrogen addition reaction to obtain a C-Si crosslinked flexible resin. The introduction of the macromolecular crosslinking agent realizes accurate regulation of the crosslinking network, and the obtained C-Si crosslinked resin has the characteristics of low dielectric loss, high flexibility, high bending fatigue resistance and the like after curing, and effectively solves the problems of single curing means of a traditional carbon hydrogen resin, high brittleness of a cured product and insufficient flexibility. The flexible C-Si crosslinked resin is suitable for the fields of high-frequency high-speed flexible copper-clad plates, wearable devices, folding screen mobile phones, flexible displays and the like.

Description

Technical Field

[0001] This invention belongs to the field of low dielectric polymer materials technology, specifically relating to a C-Si crosslinking resin for flexible copper clad laminates, and more particularly to a method for preparing a highly flexible crosslinking resin by introducing a macromolecular crosslinking agent into the crosslinking network through a hydrosilylation reaction, and its application in flexible copper clad laminates. Background Technology

[0002] With the widespread adoption of 5G technology, the preliminary research and exploration of 6G technology, and the booming development of wearable devices, foldable screen phones, flexible displays, and the Internet of Things, flexible electronic systems are placing entirely new performance requirements on core substrate materials. As a core component of flexible circuit boards, flexible copper-clad laminates (FCCLs) not only need to possess the basic electrical and thermal properties of traditional copper-clad laminates, but must also be able to withstand complex scenarios such as repeated bending, rolling, and folding without failure. This fundamental shift in application scenarios places essential new demands on the mechanical properties of the resin matrix.

[0003] Traditional rigid copper-clad laminate (CCL) resins such as epoxy resin, polyphenylene ether resin, and cyanate ester resin cannot meet the requirements of flexible CCLs. Polyimide is one of the preferred materials for flexible CCLs, but its molecular structure contains a large number of polar groups, resulting in a high intrinsic dielectric constant and strong water absorption. Polyester films have insufficient heat resistance. Polytetrafluoroethylene (PTFE) has excellent dielectric properties, but its extremely poor intrinsic thermal conductivity, high coefficient of thermal expansion, and low surface energy severely limit its practical applications. Hydrocarbon resins, with C-C and CH bonds as the main molecular chains, have extremely low intrinsic polarizability and are recognized as ideal matrix materials for next-generation high-frequency CCLs. However, current research on hydrocarbon resins mainly focuses on rigid CCLs, with few reports on flexible CCLs. Existing hydrocarbon resin curing methods mainly rely on peroxide-induced free radical crosslinking reactions, which have drawbacks such as limited curing agent selection, single curing methods, difficulty in controlling the crosslinking process, poor designability of cured product structure, high brittleness of cured products, and poor flexibility, thus limiting their application in flexible CCLs. Therefore, it is crucial to develop a novel curing method with a wide selection of crosslinking agents and a designable product structure to prepare highly flexible hydrocarbon resin dielectric materials to meet the application requirements of flexible copper clad laminates. Summary of the Invention

[0004] This invention aims to address the technical problems of existing hydrocarbon resin curing methods, such as simplistic curing methods, brittle cured products, insufficient flexibility, and difficulty in application to flexible copper-clad laminates. It develops a method for preparing highly flexible C-Si crosslinked resin by introducing a macromolecular crosslinking agent into the crosslinking network through a hydrosilylation reaction. This method, through molecular structure design, introduces long-chain structures between polymer chains, achieving precise control of the crosslinking network. This results in a cured C-Si crosslinked resin with low dielectric properties, high flexibility, and high bending resistance, suitable for the field of flexible copper-clad laminates.

[0005] The primary objective of this invention is to provide a method for preparing a flexible C-Si crosslinked resin.

[0006] Another object of the present invention is to provide a flexible C-Si crosslinked resin obtained by the above preparation method.

[0007] Another object of the present invention is to provide the application of the above-mentioned flexible C-Si crosslinked resin.

[0008] This invention is achieved through the following technical solution: A method for preparing a flexible C-Si crosslinked resin includes the following steps: (1) Add a multifunctional silane compound, a multifunctional carbon-carbon double bond compound and an organic solvent to a reaction vessel, introduce an inert gas, stir and disperse, and then heat to 50-90°C; add a catalyst and introduce an inert gas; after the gas is introduced, stir the reaction at 50-90°C, pour the resulting reaction solution into a column packed with neutral alumina, remove impurities and obtain a clear reaction solution; then add methanol, filter the white precipitate, dry it and obtain a macromolecular crosslinking agent; (2) Disperse the hydrocarbon resin containing carbon-carbon unsaturated bonds evenly in an organic solvent, then add the macromolecular crosslinking agent obtained in step (1), and mix evenly after passing in an inert gas; heat to 50-90°C, add a catalyst, and then pass in an inert gas; after the gas passage is completed, stir the reaction at 50-90°C, pour the reaction solution into a column containing neutral alumina, remove impurities to obtain a clear reaction solution, and obtain a flexible C-Si crosslinking resin.

[0009] The multifunctional silane compound mentioned in step (1) is preferably at least one of 1,4-di(dimethylsilyl)benzene, 1,3-di(dimethylsilyl)benzene, 1,2-di(dimethylsilyl)benzene, tetramethyldisiloxane, 1,3-dimethyl-1,3-diphenyldisiloxane, diphenylsilane, methylphenylsilane, dimethylsilane, diethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7,9,11-hexamethylcyclohexasiloxane, 2,4,6,8-tetraethylcyclotetrasiloxane, and hydrogen-containing cage-type polysilsesquioxane.

[0010] The polyfunctional carbon-carbon double bond compound mentioned in step (1) is preferably at least one of 1,3-butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, dicyclopentadiene, divinylbenzene, divinylnaphthalene, divinylbiphenyl, diallylbenzene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene, tetravinylsilane, tetravinylcyclotetrasiloxane, divinyldimethylsilane, diallyldimethylsilane, and 1,1,3,3-tetramethyldivinyldisiloxane.

[0011] The molar ratio of the functional groups of the polyfunctional silane hydrometallurgical compound and the polyfunctional carbon-carbon double bond compound in step (1) is 1.05 to 2.2: 1.

[0012] The organic solvent used in step (1) is preferably at least one of toluene, xylene, trimethylbenzene, benzene, ethylbenzene, hexane, cyclohexane, heptane, octane, isooctane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol methyl ether acetic acid, dichloromethane, chloroform, carbon tetrachloride, and chlorobenzene.

[0013] The organic solvent mentioned in step (1) does not participate in the reaction, as long as it can fully disperse the reaction components; the preferred amount is 0.8 to 1.2 L of organic solvent per mole of multifunctional silane compound.

[0014] The catalyst mentioned in step (1) is a hydrosilylation reaction catalyst, preferably at least one of chloroplatinic acid, an alcoholic solution of chloroplatinic acid, an olefinic complex of chloroplatinic acid, a vinylsiloxane complex of chloroplatinic acid, a caster catalyst (platinum-divinyltetramethyldisiloxane complex), a platinum-cyclovinylsiloxane complex, a platinum-vinylsiloxane complex, a platinum-olefinic complex, a platinum-carbonyl complex, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, and a nickel-based catalyst; more preferably a caster catalyst or a vinylsiloxane complex of chloroplatinic acid.

[0015] The amount of catalyst used in step (1) is the amount of catalyst used; preferably, it is 0.1 to 0.3 mL of catalyst per mole of multifunctional silane compound.

[0016] The inert gas mentioned in step (1) is preferably nitrogen, argon or helium.

[0017] The inert gas introduced in step (1) is introduced for 20 to 40 minutes; more preferably for 30 minutes.

[0018] The stirring and dispersion time in step (1) is preferably 30 to 90 minutes; more preferably 60 minutes.

[0019] The heating temperature in step (1) is preferably 75-85°C; more preferably 80°C.

[0020] The preferred temperature for the stirring reaction in step (1) is 75-85°C; more preferably 80°C.

[0021] The stirring reaction time in step (1) is preferably 5 to 15 hours; more preferably 8 to 10 hours.

[0022] The hydrocarbon resins containing carbon-carbon unsaturated bonds mentioned in step (2) include, but are not limited to, styrene-based block copolymers, polybutadiene, polyisoprene, polyolefin elastomers, styrene-butadiene rubber, nitrile rubber, ethylene propylene rubber, butyl rubber, polybutadiene-acrylonitrile copolymer, polybutadiene-styrene copolymer, and at least one of the hydrogenated or modified products of the above polymers.

[0023] The styrene-based block copolymer is preferably at least one of styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butene-styrene block copolymer (SEBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS).

[0024] The polybutadiene is preferably at least one of 1,2-polybutadiene, 1,4-polybutadiene, vinyl-terminated polybutadiene, and hydrogenated polybutadiene.

[0025] The ratio of the hydrocarbon resin to the macromolecular crosslinking agent in step (2) is calculated based on a molar ratio of silane groups to carbon-carbon unsaturated double bonds of 0.1 to 1:1; preferably 0.5 to 0.7:1.

[0026] The organic solvent used in step (2) is preferably at least one of toluene, xylene, trimethylbenzene, benzene, ethylbenzene, hexane, cyclohexane, heptane, octane, isooctane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol methyl ether acetic acid, dichloromethane, chloroform, carbon tetrachloride, and chlorobenzene.

[0027] The organic solvent mentioned in step (2) does not participate in the reaction, as long as it can fully disperse the reaction components; the preferred amount is 10-15 mL of organic solvent per gram of hydrocarbon resin containing carbon-carbon unsaturated bonds.

[0028] The catalyst mentioned in step (2) is a hydrosilylation reaction catalyst, preferably at least one of chloroplatinic acid, an alcoholic solution of chloroplatinic acid, an olefinic complex of chloroplatinic acid, a vinylsiloxane complex of chloroplatinic acid, a caster catalyst (platinum-divinyltetramethyldisiloxane complex), a platinum-cyclovinylsiloxane complex, a platinum-vinylsiloxane complex, a platinum-olefinic complex, a platinum-carbonyl complex, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, and a nickel-based catalyst; more preferably a caster catalyst or a vinylsiloxane complex of chloroplatinic acid.

[0029] The amount of catalyst used in step (2) is the amount of catalyst used; preferably, it is 0.1 to 0.2 μL of catalyst per gram of hydrocarbon resin containing carbon-carbon unsaturated bonds.

[0030] The inert gas mentioned in step (2) is preferably nitrogen, argon or helium.

[0031] The inert gas introduced in step (2) is introduced for 20 to 40 minutes; more preferably 20 to 30 minutes.

[0032] The dispersion time mentioned in step (2) is preferably 20 to 30 hours; more preferably 23 to 25 hours.

[0033] The mixing time in step (2) is preferably 30 to 90 minutes; more preferably 60 minutes.

[0034] The heating temperature in step (2) is preferably 55-65°C; more preferably 60°C.

[0035] The preferred temperature for the stirring reaction in step (2) is 55-65°C; more preferably 60°C.

[0036] The stirring reaction time in step (2) is preferably 5 to 15 hours; more preferably 8 to 10 hours.

[0037] A flexible C-Si crosslinked resin is obtained by the above preparation method.

[0038] The application of the flexible C-Si crosslinked resin in the field of communications is suitable for preparing the substrate resin layer of copper-clad laminates, communication substrates or flexible circuit boards, preferably including the following steps: contacting the above-mentioned flexible C-Si crosslinked resin with the substrate and heating and curing to obtain a flexible C-Si crosslinked resin layer.

[0039] The communication field is preferably the field of dynamic flexible electronics, including high-frequency high-speed flexible copper-clad laminates, wearable devices, foldable screen phones, and flexible displays.

[0040] The curing conditions are a temperature of 50–200℃ and a time of 1–24h; preferably a temperature of 50–160℃ and a time of 9h; the specific curing procedure is preferably as follows: 50℃ for 3h, 80℃ for 2h, 100℃ for 1h, 120℃ for 1h, 140℃ for 1h, and 160℃ for 1h. Beneficial effects

[0041] Compared with the prior art, the present invention has the following beneficial effects: (1) Breakthrough in traditional curing mode: This invention uses hydrosilylation reaction to cure resin. The curing conditions are mild. Through molecular structure design, a long-chain cross-linking structure is introduced into the cross-linking network. The cross-linking network has good uniformity, low internal stress, and good dimensional stability. This fundamentally solves the problems of high brittleness and insufficient flexibility of traditional hydrocarbon resins after curing.

[0042] (2) Expanding the range of crosslinking agents: This invention can use silicon hydro compounds and compounds containing double bonds with various structures as monomers. By adjusting the types and proportions of monomers, macromolecular crosslinking agents PSiH with different molecular weights and chemical structures can be synthesized.

[0043] (3) Excellent flexibility: By introducing a long-chain cross-linked structure, the hydrocarbon resin cured product prepared in this invention has a low Young's modulus (17.6~32.1MPa) and high tensile toughness (3.54~4.32 MJ / m). 3 It has excellent resistance to bending fatigue and is suitable for flexible copper clad laminate applications.

[0044] (4) Excellent comprehensive performance: The cured material prepared by the method of the present invention achieves excellent flexibility while maintaining a low dielectric constant (D). k <2.5, preferably 2.3 to 2.47), low dielectric loss (D f <0.01, preferably 0.0052~0.0059), high heat resistance (T d5% With a temperature range of >350℃ (preferably 375~398℃), it exhibits high water and solvent resistance, meeting the requirements for high-frequency and high-speed signal transmission. Detailed Implementation

[0045] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0046] For experiments where specific steps or conditions are not specified, the procedures and conditions described in the literature within this field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available standard products. Example 1

[0047] In a reaction flask equipped with a stirrer, thermometer, and condenser, 0.5 mol (97.2 g) of 1,4-di(dimethylsilyl)benzene (DMSB), 0.45 mol (62.2 g) of 1,9-decadiene, and 500 mL of toluene were added. Nitrogen gas was bubbled through the flask for 30 min, and the mixture was stirred for 1 h to ensure uniform dispersion. The mixture was then heated to 80 °C. 0.1 mL of Castern catalyst was added, and nitrogen gas was bubbled through the flask again for 30 min. The mixture was then stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. This solution was gradually added to 10 times its volume of methanol, producing a white precipitate. The white precipitate was filtered and dried to obtain 147.8 g of the macromolecular crosslinking agent PSiH-1, with a yield of 92.7%.

[0048] 4 g of styrene-butadiene-styrene block copolymer resin (SBS, catalog number 1,2-SBS-L42, Nippon Soda Co., Ltd., hereinafter the same) and 50 mL of xylene were added to a three-necked flask and stirred at 30 °C for 24 h to ensure uniform dispersion. Then, 10 g of macromolecular crosslinking agent PSiH-1 was added, and nitrogen gas was purged for 20 min followed by stirring for 1 h. The mixture was then heated to 60 °C, and 0.5 μL of caster catalyst was added. Nitrogen gas was purged for 30 min, and the mixture was stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. The reactant solution was poured into a polytetrafluoroethylene mold and placed in an oven to form films at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, and 160 °C / 1 h to obtain various test samples.

[0049] The thermosetting hydrocarbon resin prepared according to the aforementioned formula and process has the following performance indicators: dielectric constant 2.47 (10GHz), dielectric loss 0.0052 (10GHz), water absorption rate of 0.02% after 48 h, and thermal decomposition temperature T. d5％ The thermal expansion coefficient (CTE) at 398℃ (room temperature 200℃) is 121.6 ppm / ℃, the tensile strength is 13.5 MPa, the elongation at break is 40.8%, the tensile modulus is 32.1 MPa, and the tensile toughness is 3.54 MJ / m. 3 . Example 2

[0050] In a reaction flask equipped with a stirrer, thermometer, and condenser, 0.50 mol (97.2 g) of 1,4-di(dimethylsilyl)benzene (DMSB), 0.45 mol (83.8 g) of 1,1,3,3-tetramethyldivinyldisiloxane (VMM), and 500 mL of toluene were added. Nitrogen gas was bubbled through the flask for 30 min, and the mixture was stirred for 1 h to ensure uniform dispersion. The mixture was then heated to 80 °C. 0.1 mL of caster catalyst was added, and nitrogen gas was bubbled through the flask for another 30 min. The mixture was then stirred for 8 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. This solution was gradually added to 10 times its volume of methanol, producing a white precipitate. The white precipitate was filtered and dried to obtain 168.4 g of the macromolecular crosslinking agent PSiH-2, with a yield of 93.0%.

[0051] 4 g of SBS resin and 50 mL of xylene were added to a three-necked flask and stirred at 30 °C for 24 h to ensure uniform dispersion. Then, 10 g of the macromolecular crosslinking agent PSiH-2 was added, and nitrogen gas was purged for 20 min followed by stirring for 1 h. The mixture was then heated to 60 °C, and 0.5 μL of the caster catalyst was added. Nitrogen gas was purged for 30 min, and the mixture was stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. The reactant solution was then poured into a polytetrafluoroethylene mold and placed in an oven to form films at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, and 160 °C / 1 h, yielding various test samples.

[0052] The thermosetting hydrocarbon resin prepared according to the aforementioned formula and process has the following performance indicators: dielectric constant 2.38 (10GHz), dielectric loss 0.0057 (10GHz), water absorption rate of 0.02% after 48 h, and thermal decomposition temperature T. d5％ The thermal expansion coefficient (CTE) at 390℃ (room temperature 200℃) is 120.3 ppm / ℃, the tensile strength is 12.7 MPa, the elongation at break is 47.8%, the tensile modulus is 25.6 MPa, and the tensile toughness is 4.18 MJ / m. 3 . Example 3

[0053] In a reaction flask equipped with a stirrer, thermometer, and condenser, 0.5 mol (97.2 g) of 1,4-di(dimethylsilyl)benzene (DMSB), 0.45 mol (62.2 g) of 1,9-decadiene, and 500 mL of toluene were added. Nitrogen gas was bubbled through the flask for 30 min, and the mixture was stirred for 1 h to ensure uniform dispersion. The mixture was then heated to 80 °C. 0.1 mL of caster catalyst was added, and nitrogen gas was bubbled through the flask for another 30 min. The mixture was then stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. This solution was gradually added to 10 times its volume of methanol, producing a white precipitate. The white precipitate was filtered, dried, and yielded 147.8 g of the macromolecular crosslinking agent PSiH-1, with a yield of 92.7%.

[0054] 4 g of SBS resin and 50 mL of xylene were added to a three-necked flask and stirred at 30 °C for 24 h to ensure uniform dispersion. Then, 8 g of macromolecular crosslinking agent PSiH-1 was added, and nitrogen gas was purged for 20 min followed by stirring for 1 h. The mixture was then heated to 60 °C, and 0.5 μL of caster catalyst was added. Nitrogen gas was purged for 30 min, and the mixture was stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. The reactant solution was then poured into a polytetrafluoroethylene mold and placed in an oven to form films at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, and 160 °C / 1 h, yielding various test samples.

[0055] The thermosetting hydrocarbon resin prepared according to the aforementioned formula and process has the following performance indicators: dielectric constant 2.45 (10GHz), dielectric loss 0.0059 (10GHz), water absorption rate of 0.01% after 48 h, and thermal decomposition temperature T. d5 The thermal expansion coefficient (CTE) at 386℃ (room temperature 200℃) is 123.8 ppm / ℃, the tensile strength is 11.8 MPa, the elongation at break is 56.4%, the tensile modulus is 20.9 MPa, and the tensile toughness is 4.32 MJ / m. 3 . Example 4

[0056] In a reaction flask equipped with a stirrer, thermometer, and condenser, 0.50 mol (97.2 g) of 1,4-di(dimethylsilyl)benzene (DMSB), 0.45 mol (83.8 g) of 1,1,3,3-tetramethyldivinyldisiloxane (VMM), and 500 mL of toluene were added. Nitrogen gas was bubbled through the flask for 30 min, and the mixture was stirred for 1 h to ensure uniform dispersion. The mixture was then heated to 80 °C. 0.1 mL of caster catalyst was added, and nitrogen gas was bubbled through the flask for another 30 min. The mixture was then stirred for 8 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. This solution was gradually added to 10 times its volume of methanol, producing a white precipitate. The white precipitate was filtered and dried to obtain 168.4 g of the macromolecular crosslinking agent PSiH-2, with a yield of 93.0%.

[0057] 4 g of SBS resin and 50 mL of xylene were added to a three-necked flask and stirred at 30 °C for 24 h to ensure uniform dispersion. Then, 8 g of macromolecular crosslinking agent PSiH-2 was added, and nitrogen gas was introduced for 20 min followed by stirring for 1 h. The mixture was then heated to 60 °C, and 0.5 μL of caster catalyst was added. The reaction was stirred for 10 h. After the reaction was complete, the reactant solution was poured into a column packed with neutral alumina to remove impurities, resulting in a clear reactant solution. The reactant solution was poured into a polytetrafluoroethylene mold and placed in an oven to form films at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, and 160 °C / 1 h, yielding various test samples.

[0058] The thermosetting hydrocarbon resin prepared according to the aforementioned formula and process has the following performance indicators: dielectric constant 2.30 (10GHz), dielectric loss 0.0058 (10GHz), water absorption rate of 0.01% after 48 h, and thermal decomposition temperature T. d5％ The thermal expansion coefficient (CTE) at 376℃ (room temperature 200℃) is 123.6 ppm / ℃, the tensile strength is 10.3 MPa, the elongation at break is 60.2%, the tensile modulus is 17.6 MPa, and the tensile toughness is 3.94 MJ / m. 3 .

[0059] Comparative Example 1 10 g of PB resin, 0.1 g of di-tert-butylperoxyisopropylbenzene, 0.1 g of antioxidant 1010, and 30 g of xylene were added to a round-bottom flask and stirred at 30 °C and 600 rads / min for 24 h to ensure uniform dispersion. The mixture was then poured into a polytetrafluoroethylene mold and cured in an oven at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, 160 °C / 1 h, and 180 °C / 1 h. The resulting film exhibited a dielectric constant of 2.56 (10 GHz), a dielectric loss of 0.0061 (10 GHz), a 48 h water absorption rate of 0.02%, a tensile strength of 11.38 MPa, an elongation at break of 6%, a tensile modulus of 0.248 GPa, and a tensile toughness of 0.419 MJ / m. 3 The cured product exhibits obvious brittle fracture.

[0060] Comparative Example 2 10 g of SBS resin, 0.1 g of di-tert-butylperoxyisopropylbenzene, 0.1 g of antioxidant 1010, and 30 g of xylene were added to a round-bottom flask and stirred at 30 °C and 600 rads / min for 24 h to ensure uniform dispersion. The mixture was then poured into a polytetrafluoroethylene mold and cured in an oven at 50 °C / 3 h, 80 °C / 2 h, 100 °C / 1 h, 120 °C / 1 h, 140 °C / 1 h, 160 °C / 1 h, and 180 °C / 1 h. The resulting film exhibited a dielectric constant of 2.60 (10 GHz), a dielectric loss of 0.0065 (10 GHz), a 48 h water absorption rate of 0.02%, a tensile strength of 17.43 MPa, an elongation at break of 4%, a tensile modulus of 0.365 GPa, and a tensile toughness of 0.426 MJ / m. 3 The cured product exhibits obvious brittle fracture.

[0061] Compared with Examples 1 to 4, the cured products in Comparative Examples 1 to 2 are more brittle. Furthermore, as the content of di-tert-butylperoxyisopropylbenzene increases, the brittleness of the cured products increases, and the dielectric properties deteriorate, resulting in the unusability of the cured products.

[0062] Compared to Examples 1-4, the cured products of Comparative Examples 1-2 all exhibited significant brittleness and poor mechanical properties, failing to meet the requirements for flexible copper-clad laminates. Furthermore, with increasing bis-tert-butylperoxyisopropylbenzene content, the brittleness of the cured products increased, while the dielectric properties deteriorated. In contrast, the cured products of Examples 1-4 were soft and tough dielectric films with good flexibility, suitable for use in flexible copper-clad laminate materials.

[0063] The testing methods in this invention adopt the following standards: Dielectric constant Dk and dielectric loss tangent D f Data measured at 10 GHz using a Keysight E5080B oscillator.

[0064] Linear thermal expansion coefficient (CTE): Data were measured from room temperature to 200°C using a NETZSCH TMA 402 F3 thermometer at a heating rate of 5 °C / min under a nitrogen atmosphere.

[0065] 5% thermal decomposition temperature T d5% Data were measured from room temperature to 600°C using a NETZSCH TG 209 F1 thermometer from Germany at a heating rate of 20 °C / min under a nitrogen atmosphere.

[0066] Tensile strength, elongation at break, tensile modulus, and tensile toughness: The stress-strain curves of the resin film were measured using a KJ-1067 from Dongguan Kejian Co., Ltd. at a rate of 15 mm / min. The tensile modulus was the slope of the stress-strain curve, and the tensile toughness was the integral area of ​​the stress-strain curve.

[0067] Water absorption rate: The sample was immersed in pure water at room temperature for 48 h, weighed and the mass change was recorded.

[0068] The technical contents of this invention and the above embodiments that are not specifically described are the same as those of the prior art, and the raw materials are all commercially available products.

[0069] The present invention is not limited to the above embodiments; all embodiments described herein can be implemented and have the aforementioned good effects.

[0070] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a flexible C-Si crosslinked resin, characterized in that... The steps include the following: (1) Add a multifunctional silane compound, a multifunctional carbon-carbon double bond compound and an organic solvent to a reaction vessel, introduce an inert gas, stir and disperse, and then heat to 50-90°C; add a catalyst and introduce an inert gas; after the gas is introduced, stir the reaction at 50-90°C, pour the resulting reaction solution into a column packed with neutral alumina, remove impurities and obtain a clear reaction solution; then add methanol, filter the white precipitate, dry it and obtain a macromolecular crosslinking agent; (2) Disperse the hydrocarbon resin containing carbon-carbon unsaturated bonds evenly in an organic solvent, then add the macromolecular crosslinking agent obtained in step (1), and mix evenly after passing in an inert gas; heat to 50-90°C, add a catalyst, and then pass in an inert gas; after the gas passage is completed, stir the reaction at 50-90°C, pour the reaction solution into a column containing neutral alumina, remove impurities to obtain a clear reaction solution, and obtain a flexible C-Si crosslinking resin.

2. The method for preparing the flexible C-Si crosslinked resin according to claim 1, characterized in that: The multifunctional silane compound mentioned in step (1) is at least one of 1,4-di(dimethylsilyl)benzene, 1,3-di(dimethylsilyl)benzene, 1,2-di(dimethylsilyl)benzene, tetramethyldisiloxane, 1,3-dimethyl-1,3-diphenyldisiloxane, diphenylsilane, methylphenylsilane, dimethylsilane, diethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane, 1,3,5,7,9,11-hexamethylcyclohexasiloxane, 2,4,6,8-tetraethylcyclotetrasiloxane, and hydrogen-containing cage-type polysilsesquioxane; The polyfunctional carbon-carbon double bond compound mentioned in step (1) is at least one of 1,3-butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, dicyclopentadiene, divinylbenzene, divinylnaphthalene, divinylbiphenyl, diallylbenzene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene, tetravinylsilane, tetravinylcyclotetrasiloxane, divinyldimethylsilane, diallyldimethylsilane, and 1,1,3,3-tetramethyldivinyldisiloxane. The organic solvent mentioned in step (1) is at least one of toluene, xylene, trimethylbenzene, benzene, ethylbenzene, hexane, cyclohexane, heptane, octane, isooctane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol methyl ether acetic acid, dichloromethane, chloroform, carbon tetrachloride, and chlorobenzene; The catalyst mentioned in step (1) is at least one of the following: chloroplatinic acid, an alcoholic solution of chloroplatinic acid, an olefinic complex of chloroplatinic acid, a vinylsiloxane complex of chloroplatinic acid, a cassiterite catalyst (platinum-divinyltetramethyldisiloxane complex), a platinum-cyclovinylsiloxane complex, a platinum-vinylsiloxane complex, a platinum-olefinic complex, a platinum-carbonyl complex, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, and a nickel-based catalyst.

3. The method for preparing the flexible C-Si crosslinked resin according to claim 2, characterized in that: The molar ratio of the functional groups of the polyfunctional silane hydrometallurgical compound and the polyfunctional carbon-carbon double bond compound in step (1) is 1.05 to 2.2: 1; The amount of organic solvent used in step (1) is 0.8 to 1.2 L of organic solvent per mole of multifunctional silane compound; The amount of catalyst used in step (1) is 0.1 to 0.3 mL of catalyst per mole of multifunctional silane compound.

4. The method for preparing the flexible C-Si crosslinked resin according to claim 3, characterized in that: The inert gas mentioned in step (1) is nitrogen, argon or helium; The inert gas introduced in step (1) is introduced for 20 to 40 minutes; The stirring and dispersing time in step (1) is 30 to 90 minutes; The heating temperature mentioned in step (1) is 75-85℃; The temperature of the stirring reaction described in step (1) is 75–85°C; The stirring reaction time described in step (1) is 5 to 15 hours.

5. The method for preparing the flexible C-Si crosslinked resin according to claim 1, characterized in that: The hydrocarbon resin containing carbon-carbon unsaturated bonds mentioned in step (2) is at least one of the following: styrene block copolymer, polybutadiene, polyisoprene, polyolefin elastomer, styrene-butadiene rubber, nitrile rubber, ethylene propylene rubber, butyl rubber, polybutadiene-acrylonitrile copolymer, polybutadiene-styrene copolymer, and hydrogenated or modified products of the above polymers. The organic solvent mentioned in step (2) is at least one of toluene, xylene, trimethylbenzene, benzene, ethylbenzene, hexane, cyclohexane, heptane, octane, isooctane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol methyl ether acetic acid, dichloromethane, chloroform, carbon tetrachloride, and chlorobenzene; The catalyst mentioned in step (2) is at least one of the following: chloroplatinic acid, an alcoholic solution of chloroplatinic acid, an olefinic complex of chloroplatinic acid, a vinylsiloxane complex of chloroplatinic acid, a cassiterite catalyst (platinum-divinyltetramethyldisiloxane complex), a platinum-cyclovinylsiloxane complex, a platinum-vinylsiloxane complex, a platinum-olefinic complex, a platinum-carbonyl complex, a palladium-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, and a nickel-based catalyst.

6. The method for preparing the flexible C-Si crosslinked resin according to claim 5, characterized in that: The ratio of the hydrocarbon resin to the macromolecular crosslinking agent in step (2) is calculated based on a molar ratio of silane groups to carbon-carbon unsaturated double bonds of 0.1 to 1:

1. The amount of organic solvent used in step (2) is 10-15 mL of organic solvent per gram of hydrocarbon resin containing carbon-carbon unsaturated bonds. The amount of catalyst used in step (2) is 0.1 to 0.2 μL of catalyst per gram of hydrocarbon resin containing carbon-carbon unsaturated bonds.

7. The method for preparing the flexible C-Si crosslinked resin according to claim 6, characterized in that: The inert gas mentioned in step (2) is nitrogen, argon or helium; The inert gas introduced in step (2) is introduced for 20 to 40 minutes; The dispersion time mentioned in step (2) is 20-30 hours; The mixing time described in step (2) is 30–90 min; The heating temperature mentioned in step (2) is 55-65℃; The temperature of the stirring reaction in step (2) is 55-65℃; The stirring reaction time described in step (2) is 5 to 15 hours.

8. A flexible C-Si crosslinking resin, characterized in that: It is obtained by the preparation method according to any one of claims 1 to 7.

9. The application of the flexible C-Si crosslinked resin according to claim 8 in the field of communications.

10. The application of the flexible C-Si crosslinked resin according to claim 9 in the preparation of a substrate resin layer, characterized in that... The process includes the following steps: contacting the flexible C-Si crosslinked resin of claim 8 with the substrate, heating and curing to obtain a flexible C-Si crosslinked resin layer.