Acenaphthene alkenyl fluorine-containing hydrocarbon resin for M9-grade copper-clad plate and preparation method thereof

Abstract

The invention belongs to the technical field of electronic-grade resin, and particularly relates to acenaphthene alkenyl fluorine-containing hydrocarbon resin for an M9-grade copper-clad plate and a preparation method thereof.The preparation method comprises the following steps that S1, fluorine-containing monomer preparation is conducted, specifically, dicyclopentadiene is cracked and distilled to obtain fresh cyclopentadiene, pentafluorostyrene and the fresh cyclopentadiene are mixed according to the molar ratio of 1: 1.2-1.5, and a fluorine-containing monomer is obtained; 5-(pentafluorophenyl)-2-norbornene with the purity being greater than or equal to 99.95%, namely a fluorine-containing monomer, is obtained through D-A reaction, post-treatment and refining; s2, preparation of a mixed monomer: mixing an acenaphthylene monomer with a fluorine-containing monomer, and purifying to obtain a refined mixed monomer with the purity being greater than or equal to 99.95%; s3, polymerization reaction: carrying out addition polymerization reaction on the refined mixed monomer, a metallocene catalyst and an organic solvent under the protection of inert gas to obtain a crude product; s4, purification treatment: purifying the crude product to obtain hydrocarbon resin of which the purity is greater than or equal to 99.99%; and S5, post-treatment: preparing the purified hydrocarbon resin into finished resin.

Description

Acenamethanone-based fluorocarbon resin for M9 grade copper clad laminate and its preparation method Technical Field

[0001] This invention belongs to the field of electronic grade resin technology, specifically relating to an acenaphthene-based fluorocarbon resin for M9 grade copper clad laminates and its preparation method. Background Technology

[0002] As electronic devices become increasingly higher frequency and higher speed, extremely high requirements are placed on the dielectric properties, heat resistance, dimensional stability, and purity of electronic-grade resins. Hydrocarbon resins, due to the absence of polar groups in their molecular structure and their naturally low dielectric constant (Dk) and dielectric loss (Df), have become a core choice for high-frequency and high-speed electronic materials.

[0003] Acenaphthene, as a polycyclic aromatic hydrocarbon monomer, contains a naphthalene ring skeleton in its molecular structure. It possesses characteristics such as high rigidity, excellent heat resistance, and extremely low molecular polarity. Its homopolymer or copolymer resins exhibit good heat resistance and dielectric properties, making them a superior monomer choice for high-frequency, high-speed hydrocarbon resins. However, current acenaphthene-based hydrocarbon resins suffer from the following key drawbacks, failing to meet the demands of high-end electronic applications: a high coefficient of thermal expansion (CTE) (>60ppm / ℃), leading to warping and cracking during high-temperature curing and end-use, affecting substrate dimensional accuracy; excessive rigidity of acenaphthene homopolymer resins, resulting in embrittlement and poor processability; when single acenaphthene-based hydrocarbon resins are compounded with epoxy, benzoxazine, and other resins, delamination and phase separation easily occur, leading to a decline in the overall performance of the composite material and hindering industrial application; existing acenaphthene-based hydrocarbon resins have a water absorption rate exceeding 0.08%, easily absorbing water in humid environments, causing dielectric property degradation and making them unsuitable for the long-term stable operation requirements of high-frequency electronic devices.

[0004] Most fluorinated monomers can only undergo free radical polymerization. In free radical polymerization, the chain growth of fluorinated monomers is prone to chain transfer, resulting in a wider molecular weight distribution and increased branching, leading to insufficient purity of the target product. At the same time, the free radical lifetime of special fluorinated monomers adapted to high-frequency and high-speed resins is extremely short, and the cross-growth rate is low. In contrast, acenaphthene has a highly conjugated rigid structure, strong free radical stability, and a significant tendency for self-polymerization. Therefore, the ratio of their polymerization rates usually deviates from 1, easily forming block structures rather than uniform random / alternating copolymers, leading to performance fluctuations and an inhibitory effect, resulting in a significant reduction in polymerization efficiency and making it impossible to obtain high-purity fluorinated acenaphthene hydrocarbon resins.

[0005] Therefore, overcoming the deficiency of purity in fluorinated acenaphthene-based hydrocarbon resins caused by the easy formation of block structures between fluorinated monomers and acenaphthene is a technical problem that urgently needs to be solved in this field.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0007] This disclosure provides at least one acenaphthene-based fluorocarbon resin for M9 grade copper clad laminates and its preparation method.

[0008] In a first aspect, embodiments of this disclosure provide a method for preparing an acenaphthene-based fluorinated hydrocarbon resin, comprising the following steps: S1, preparation of fluorinated monomers: fresh cyclopentadiene is obtained by cracking and distilling dicyclopentadiene; pentafluorostyrene and fresh cyclopentadiene are mixed at a molar ratio of 1:1.2-1.5; after DA reaction, post-treatment and purification, 5-(pentafluorophenyl)-2-norbornene with a purity ≥99.95% is obtained, i.e., a fluorinated monomer; S2, preparation of mixed monomers: acenaphthene monomers and fluorinated monomers are mixed and purified to obtain a purified mixed monomer with a purity ≥99.95%; S3, polymerization reaction: under inert gas protection, the purified mixed monomers, metallocene catalyst and organic solvent are subjected to an addition polymerization reaction to obtain a crude product; S4, purification treatment: the crude product is purified to obtain a hydrocarbon resin with a purity ≥99.99%; S5, post-treatment: the purified hydrocarbon resin is processed into a finished resin.

[0009] In one optional embodiment, the chemical reaction formula for the DA reaction in S1 is: .

[0010] In one optional embodiment, the DA reaction in S1 is a Diels-Alder [4+2] cycloaddition reaction, with a reaction temperature of 80–120°C, a stirring rate of 150–250 r / min, a reaction time of 6–12 h, and the reaction solvent being toluene or a solvent-free bulk reaction; the post-treatment and purification in S1 includes cooling the reaction solution to room temperature, removing unreacted cyclopentadiene and solvent under reduced pressure, and purifying the crude product by vacuum distillation or recrystallization in a mixed solvent of ethanol / hexane; wherein the temperature of the vacuum distillation is 110–120°C, and the vacuum degree is not higher than 1 mmHg.

[0011] In one optional embodiment, the polymerization reaction in S3 includes: in a reaction vessel, controlling the reaction temperature at 60–90°C, the stirring rate at 200–300 r / min, and the reaction time at 5–9 h; the chemical reaction formula of the polymerization reaction is: R1, R2, and R3 are each independently selected from any one of hydrogen atoms, methyl, ethyl, trifluoromethyl, allyl, and pentafluoroethyl; the degree of polymerization m of the acenaphthene unit ranges from 30 to 150, the degree of polymerization n of the fluorinated monomer unit ranges from 20 to 80, and m:n = 1.5:1 to 7.5:1.

[0012] In one optional embodiment, the inert gas in S3 is either nitrogen or argon, and the flow rate of the inert gas is 0.5 to 1 L / min; the organic solvent is either cyclohexane or toluene, and the amount of organic solvent used is 1 to 2 times the mass of the mixed monomers; the metallocene catalyst is either zirconium dicene or titanocene, and the amount of metallocene catalyst used is 0.01-0.05% of the total monomer mass.

[0013] In one optional embodiment, the purification process in S4 includes sequential water washing, ion exchange, and vacuum devolatilization; wherein the water washing is performed at least three times, and the amount of water used each time is 0.5 times the mass of the crude product; the ion exchange uses cation exchange resin, and the exchange time is 2 to 4 hours; the vacuum devolatilization process is performed at a temperature of 130 to 160°C and a vacuum degree of 0.09 to 0.1 MPa.

[0014] In one optional embodiment, the post-processing in S5 includes cooling, crushing, and sieving; the particle size of the finished resin is 100-200 mesh.

[0015] Secondly, this disclosure also provides a acenaphthene-based fluorocarbon resin prepared by the method described above. In the molecular structure of the acenaphthene-based fluorocarbon resin, acenaphthene units and fluorinated monomer units are alternately or randomly distributed. The degree of polymerization m of the acenaphthene unit ranges from 30 to 150, and the degree of polymerization n of the fluorinated monomer unit ranges from 20 to 80, with m:n = 1.5:1 to 7.5:1. The acenaphthene-based fluorocarbon resin has a polymerization degree of 1... The dielectric constant Dk in the 0GHz band is 2.5–2.9, and the dielectric loss Df ≤ 0.004; the purity of the acenaphthene-based fluorocarbon resin is ≥ 99.99%, and the total metal ion content is < 3 ppm; the glass transition temperature Tg of the acenaphthene-based fluorocarbon resin is ≥ 230℃, the coefficient of thermal expansion CTE is 35–55 ppm / ℃, the water absorption rate is ≤ 0.05%, the water contact angle is ≥ 110°, and the molecular weight distribution PDI is 1.8–2.5.

[0016] Thirdly, embodiments of this disclosure also provide a acenaphthene-based fluorocarbon resin composition, comprising the following components in parts by weight: 60-80 parts of the acenaphthene-based fluorocarbon resin as described above, 10-20 parts of benzoxazine resin, 5-15 parts of low-dielectric filler, 0.5-2 parts of curing accelerator, and 0.1-1 parts of coupling agent; wherein the low-dielectric filler is hollow glass microspheres or porous SiO2, the curing accelerator is an imidazole derivative, and the coupling agent is silane coupling agent KH-560.

[0017] In one optional embodiment, the acenaphthene-based fluorocarbon resin composition has a dielectric constant Dk of 2.6 to 3.0 and a dielectric loss Df ≤ 0.0045 in the 10 GHz band; the glass transition temperature Tg of the acenaphthene-based fluorocarbon resin composition is ≥ 240 °C, the coefficient of thermal expansion CTE is ≤ 50 ppm / °C, the UL94 flame retardant rating is V-0, the water absorption rate is ≤ 0.55%, and the water contact angle is ≥ 110°.

[0018] The beneficial effects of this invention are as follows: the acenaphthene-based fluorinated hydrocarbon resin for M9 grade copper clad laminates and its preparation method involve preparing high-purity fluorinated monomers through in-situ DA reaction. Simultaneously, the main molecular chain is a saturated carbon chain formed by the addition polymerization of acenaphthene and 5-(pentafluorophenyl)-2-norbornene. The naphthalene ring skeleton of the acenaphthene unit is spaced apart in the main chain, and the pentafluorophenyl substituents are connected to the side chains of the norbornene unit, ensuring uniform dispersion of the fluorinated groups and fully utilizing the low dielectric and high hydrophobic effects. At the same time, the naphthalene ring skeleton enhances molecular rigidity and heat resistance, and the acenaphthene unit provides a rigid naphthalene ring skeleton, significantly improving the resin's glass transition temperature and heat resistance. Furthermore, its non-polar structure further reduces the resin's dielectric loss and improves its dimensional stability. The pentafluorophenyl has extremely strong hydrophobicity and low polarity, effectively reducing the resin's surface energy, improving hydrophobicity, and reducing water absorption, while further optimizing the resin's dielectric properties. Moreover, its cyclic olefin structure has excellent compatibility with acenaphthene, avoiding phase separation during copolymerization.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In this article, the DA reaction is referred to as the Diels-Alder reaction, also known as diene synthesis. It is the most classic and important [4+2] cycloaddition reaction in organic chemistry. It is a process in which a six-membered ring (cyclohexene or cyclohexadiene derivative) is formed in one step by a conjugated diene (4π electron system) and a dienophile (2π electron system, usually an alkene or alkyne) through a concerted mechanism.

[0023] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0024] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0025] As a core enterprise in the field of electronic-grade resins, Dongcai Technology has disclosed several patents related to high-frequency and high-speed hydrocarbon resins. Patent No. 202510907698.3, entitled "A High-Heat-Resistant, Low-Dielectric-Loss Hydrocarbon Resin, Resin Composition for Copper Clad Laminates and Its Preparation Method and Application," discloses a high-heat-resistant, low-dielectric-loss hydrocarbon resin, a resin composition for copper clad laminates, and its preparation method and application. It mainly uses vinylbenzene and its derivatives and alkyl diene derivatives in a cationic polymerization process, and forms a composition with coupling agents, fillers, etc., for use in high-frequency and high-speed copper clad laminates. However, the third monomer used is a small-molecule, low-boiling-point gas or liquid, requiring high precision in polymerization operations. Furthermore, the formulation does not consider the influence of water vapor on dielectric and dielectric loss. Patent Application No. CN202411487764.8, entitled "A Low-Dielectric-Loss Hydrocarbon Resin, Resin Composition for Copper Clad Laminates and Its Preparation Method and Application," further discloses this patent. The patent applications CN113980370B and CN202411086823.0, "A high-hardness, high-peel-strength, yellowing-resistant hydrocarbon resin composition, its preparation method and uses," both use phenolic monomers. The polar structure of phenols can affect dielectric loss performance. The patent application CN202411086823.0, "Halogen-free flame-retardant modified hydrocarbon resin and its preparation method, resin composition for copper-clad laminates and its applications," first involves a hydrosilylation reaction between the hydrocarbon resin and organosilicon, followed by a Heck reaction between the addition product and halogenated benzocyclobutene. The resulting benzocyclobutene-modified silicon hydrocarbon resin is then hydrogenated to obtain the halogen-free flame-retardant hydrocarbon resin. The process design involves a catalytic hydrogenation reaction, which requires high-pressure equipment and various precious metal catalysts.

[0026] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure below should be considered as the inventor's contribution to this disclosure.

[0027] The following describes some embodiments of the present invention in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] This disclosure provides a method for preparing acenaphthene-based fluorinated hydrocarbon resin, comprising the following steps: S1, preparation of fluorinated monomer: fresh cyclopentadiene is obtained by cracking and distilling dicyclopentadiene; pentafluorostyrene and fresh cyclopentadiene are mixed at a molar ratio of 1:1.2-1.5; after DA reaction, post-treatment and purification, 5-(pentafluorophenyl)-2-norbornene with a purity ≥99.95% is obtained, i.e., fluorinated monomer; S2, preparation of mixed monomer: acenaphthene monomer and fluorinated monomer are mixed and purified to obtain purified mixed monomer with a purity ≥99.95%; S3, polymerization reaction: under inert gas protection, the purified mixed monomer, metallocene catalyst and organic solvent are subjected to addition polymerization reaction to obtain crude product; S4, purification treatment: the crude product is purified to obtain hydrocarbon resin with a purity ≥99.99%; S5, post-treatment: the purified hydrocarbon resin is processed into finished resin.

[0029] Specifically, the purity of the acenaphthene monomer is ≥99.95%, obtained by vacuum distillation at a temperature of 120–140°C and a vacuum degree of 0.1–0.5 mmHg.

[0030] Specifically, the fluorinated monomer 5-(pentafluorophenyl)-2-norbornene has a purity of ≥99.95% and the contents of metal ions Fe, Cu, Na, and K are each <1ppm. It is obtained by reacting pentafluorostyrene with fresh cyclopentadiene via a Diels-Alder [4+2] cycloaddition reaction, followed by vacuum distillation or recrystallization.

[0031] Specifically, to further improve the hydrophobicity of the resin and reduce its water absorption rate, the fluorinated monomers in the mixed monomers account for 5% to 20% of the total monomer mass. This effectively reduces the resin surface energy, significantly improves hydrophobicity, and avoids a decline in resin processing performance due to an excessively high proportion of fluorinated monomers. The purity of the total monomers (acenaphthene monomers + fluorinated monomers) is ≥99.95%, which can be obtained through multi-stage distillation purification. In some embodiments, specifically, the chemical reaction formula for the DA reaction in S1 is: .

[0032] In some embodiments, specifically, the DA reaction in S1 is a Diels-Alder [4+2] cycloaddition reaction, the reaction temperature is 80-120°C, the stirring rate is 150-250 r / min, the reaction time is 6-12 h, and the reaction solvent is toluene or a solvent-free bulk reaction; the post-treatment and purification in S1 includes cooling the reaction solution to room temperature, removing unreacted cyclopentadiene and solvent under reduced pressure, and purifying the crude product by vacuum distillation or recrystallization in a mixed solvent of ethanol / hexane; wherein, the temperature of the vacuum distillation is 110-120°C, and the vacuum degree is not higher than 1 mmHg.

[0033] In some embodiments, specifically, the polymerization reaction in S3 includes: in a reaction vessel, controlling the reaction temperature at 60–90°C, the stirring rate at 200–300 r / min, and the reaction time at 5–9 h; the chemical reaction formula of the polymerization reaction is: R1, R2, and R3 are each independently selected from any one of hydrogen atoms, methyl, ethyl, trifluoromethyl, allyl, and pentafluoroethyl; the degree of polymerization m of the acenaphthene unit ranges from 30 to 150, the degree of polymerization n of the fluorinated monomer unit ranges from 20 to 80, and m:n = 1.5:1 to 7.5:1.

[0034] In some embodiments, specifically, the inert gas in S3 is either nitrogen or argon, and the flow rate of the inert gas is 0.5 to 1 L / min; the organic solvent is either cyclohexane or toluene, and the amount of organic solvent used is 1 to 2 times the mass of the mixed monomers; the metallocene catalyst is either zirconium dicene or titanocene, and the amount of metallocene catalyst used is 0.01-0.05% of the total monomer mass.

[0035] In some embodiments, specifically, the purification process in S4 includes sequential water washing, ion exchange, and vacuum devolatilization; wherein the number of water washings is not less than 3, and the amount of water used in each washing is 0.5 times the mass of the crude product; the ion exchange uses cation exchange resin, and the exchange time is 2 to 4 hours; the temperature of the vacuum devolatilization process is 130 to 160°C, and the vacuum degree is 0.09 to 0.1 MPa.

[0036] In some embodiments, specifically, the post-processing in S5 includes cooling, crushing, and sieving; the particle size of the finished resin is 100-200 mesh.

[0037] This disclosure also provides an acenaphthene-based fluorocarbon resin prepared by the method described above. In the molecular structure of the acenaphthene-based fluorocarbon resin, acenaphthene units and fluorinated monomer units are alternately or randomly distributed. The degree of polymerization (m) of the acenaphthene units ranges from 30 to 150, and the degree of polymerization (n) of the fluorinated monomer units ranges from 20 to 80, with m:n = 1.5:1 to 7.5:1. The acenaphthene-based fluorocarbon resin is soluble in 10 GH. The dielectric constant Dk in the z-band is 2.5–2.9, and the dielectric loss Df ≤ 0.004; the purity of the acenaphthene-based fluorocarbon resin is ≥ 99.99%, and the total metal ion content is < 3 ppm; the glass transition temperature Tg of the acenaphthene-based fluorocarbon resin is ≥ 230℃, the coefficient of thermal expansion CTE is 35–55 ppm / ℃, the water absorption rate is ≤ 0.05%, the water contact angle is ≥ 110°, and the molecular weight distribution PDI is 1.8–2.5.

[0038] Specifically, this invention innovatively employs addition copolymerization of acenaphthene with in-situ prepared high-purity fluorinated monomers, fully leveraging the high rigidity and high heat resistance of the acenaphthene naphthalene ring skeleton and the low dielectric and high hydrophobicity of the fluorinated monomers. This not only results in a hydrocarbon resin with a Dk as low as 2.5-2.9 and Df≤0.004 in the 10GHz band, significantly superior to existing acenaphthene-based hydrocarbon resins (Df 0.005-0.009), effectively reducing high-frequency signal attenuation and making it suitable for millimeter-wave and M9-level high-speed transmission scenarios; but also a Tg≥230℃, demonstrating significantly improved heat resistance compared to existing norbornene-based and conventional acenaphthene-based hydrocarbon resins, meeting the needs of high-end electronic devices under high-temperature conditions.

[0039] Specifically, a combined purification process is adopted, including DA reaction refining of fluorinated monomers, vacuum distillation of acenaphthene monomers, multi-stage distillation of mixed monomers, ion exchange, and vacuum distillation. The resin purity is ≥99.99%, the metal ion content is <3ppm, the purity of fluorinated monomers is ≥99.95%, and the purity of acenaphthene monomers is ≥99.95%. This solves the problems of high purification difficulty of existing acenaphthene monomers, substandard purity of dedicated fluorinated monomers, and difficulty in obtaining them. It meets the high purity requirements of electronic-grade resins and avoids the impact of impurities on the stability of electronic equipment.

[0040] Specifically, the CTE is controlled at 35-55ppm / ℃, and the Tg is ≥230℃. This prevents warping and cracking during high-temperature curing and use, improving the dimensional accuracy and service life of the substrate. At the same time, the introduction of the fluorinated monomer (5-(pentafluorophenyl)-2-norbornene) reduces the resin's water absorption rate to ≤0.05%, and the water contact angle to ≥110°, significantly improving hydrophobicity and effectively resisting erosion in humid environments, thus preventing the dielectric properties from decreasing due to moisture. The synergistic effect of acenaphthene and the fluorinated monomer also improves the resin's embrittlement problem and enhances processing performance.

[0041] This disclosure also provides a acenaphthene-based fluorocarbon resin composition, comprising the following components in parts by weight: 60-80 parts of the acenaphthene-based fluorocarbon resin as described above, 10-20 parts of benzoxazine resin, 5-15 parts of low-dielectric filler, 0.5-2 parts of curing accelerator, and 0.1-1 parts of coupling agent; wherein the low-dielectric filler is hollow glass microspheres or porous SiO2, the curing accelerator is an imidazole derivative, and the coupling agent is silane coupling agent KH-560.

[0042] In some embodiments, specifically, the dielectric constant Dk of the acenaphthene-based fluorocarbon resin composition is 2.6 to 3.0 in the 10 GHz band, and the dielectric loss Df is ≤0.0045; the glass transition temperature Tg of the acenaphthene-based fluorocarbon resin composition is ≥240℃, the coefficient of thermal expansion CTE is ≤50ppm / ℃, the UL94 flame retardant rating is V-0, the water absorption rate is ≤0.55%, and the water contact angle is ≥110°.

[0043] Specifically, when the acenaphthene-based hydrocarbon resin of this invention is compounded with resins such as benzoxazine and epoxy, there is no stratification or phase separation. The composite material exhibits stable overall performance and can be widely used in products such as copper-clad laminates and substrates. Simultaneously, the in-situ prepared fluorinated monomers have good compatibility with acenaphthene monomers, avoiding phase separation during polymerization, ensuring resin structural uniformity, and further optimizing the overall resin performance. Experimental verification shows that after compounding the resin of this invention with benzoxazine resin, the interfacial bonding strength is increased by more than 25%, with no significant phase separation.

[0044] Example 1: Preparation of a acenaphthene-based low dielectric loss, high heat-resistant hydrocarbon resin. Dicyclopentadiene was added to a distillation apparatus and heated to 170°C for cracking and distillation. The fraction collected at 40-42°C yielded fresh cyclopentadiene monomer, which was stored at 0-5°C under nitrogen protection for use within 12 hours. Under nitrogen protection, 19.4 g (0.1 mol) of pentafluorostyrene and 8.2 g (0.12 mol, 1.2 eq) of fresh cyclopentadiene were added to a dry reaction vessel, along with 50 mL of toluene as a solvent. The reaction temperature was controlled at 90°C, and the stirring speed at 200 r / min. The reaction was carried out for 8 hours. Gas chromatography was used to monitor the conversion rate of pentafluorostyrene, which was ≥99%, at which point the reaction was stopped. The reaction solution was cooled to room temperature, and unreacted cyclopentadiene (40℃ / 20mmHg) and toluene solvent were removed under reduced pressure. The crude product was then subjected to vacuum distillation (115℃ / 1mmHg), and the main fraction was collected to obtain 21.9 g of electronic-grade 5-(pentafluorophenyl)-2-norbornene, with a yield of 89%. Analysis showed that the monomer purity was 99.96%, and the metal ions Fe: 0.5 ppm, Cu: 0.3 ppm, and Na: 0.2 ppm met the requirements for electronic grade.

[0045] 90g of acenaphthene monomer (purity 99.95%) was mixed with 10g of the fluorinated monomer (5-(pentafluorophenyl)-2-norbornene) prepared above (fluorinated monomer content 10%). The distillation temperature was controlled at 120℃ and the vacuum degree was 0.08MPa. Three-stage distillation was carried out to remove impurities and moisture, and a refined mixed monomer with a purity of 99.96% was obtained.

[0046] Under nitrogen protection at a flow rate of 0.8 L / min, 100 g of refined mixed monomers, 0.03 g of zirconium diacene catalyst, and 150 g of cyclohexane were added to the reactor. The reaction temperature was controlled at 75 °C to suit the polymerization activity of acenaphthene, the stirring rate was 250 r / min, and the reaction time was 7 h to carry out the addition polymerization reaction, yielding crude acenaphthene-fluorinated copolymer hydrocarbon resin. The crude product was washed three times with deionized water, each time using 0.5 times the mass of the crude product, to remove the catalyst. Subsequently, it was passed through a cation exchange resin for 3 h to remove metal ions. Finally, it was subjected to vacuum devolatilization at 145 °C and a vacuum degree of 0.095 MPa for 5 h to remove organic solvents and residual monomers, yielding crude hydrocarbon resin. The crude product was cooled to room temperature, pulverized, and sieved to obtain 87 g of hydrocarbon resin product with a particle size of 150 mesh, with a yield of 87%.

[0047] The performance of the hydrocarbon resin prepared in Example 1 was tested, and the results are as follows: dielectric constant (Dk, 10GHz): 2.7; dielectric loss (Df, 10GHz): 0.0035; purity: 99.992%; Fe content: 0.6ppm, Cu content: 0.4ppm, Na content: 0.3ppm, total metal ion content 1.3ppm < 3ppm; glass transition temperature (Tg): 235℃; coefficient of thermal expansion (CTE, 25-200℃): 48ppm / ℃; water absorption (25℃, 24h): 0.04%; water contact angle: 118°, excellent hydrophobicity; molecular weight distribution (PDI): 2.2; good processing performance, no embrittlement; flame retardant rating: UL94 V-0.

[0048] Example 2: Preparation and Properties of Hydrocarbon Resin Composition 70 parts of acenaphthene-based hydrocarbon resin, 15 parts of benzoxazine resin, 10 parts of hollow glass microspheres, 1 part of imidazole curing accelerator, and 0.5 parts of silane coupling agent KH-560 were prepared in Example 1. The above components were added to a high-speed mixer and mixed at 80°C for 30 min at a speed of 1500 r / min to obtain the hydrocarbon resin composition. At 10 GHz, Dk=2.8, Df=0.0042; Tg=242°C; CTE=45ppm / °C; water absorption=0.045%, water contact angle=112°, exhibiting excellent hydrophobicity; copper foil peel strength=1.8 N / mm, demonstrating good processing performance, meeting the requirements for M9 grade copper clad laminates, and showing no significant attenuation of dielectric properties under humid conditions (85°C, 85%RH, 1000h) (Dk change ≤0.05, Df change ≤0.0003).

[0049] Example 3: Preparation and properties of acenaphthene-based hydrocarbon resin with 15% fluorinated monomer. 85g of acenaphthene monomer (purity 99.95%) was mixed with 15g of the fluorinated monomer (5-(pentafluorophenyl)-2-norbornene) prepared above (fluorinated monomer content 15%). The distillation temperature was controlled at 125℃ and the vacuum degree was 0.08MPa. Three-stage distillation was carried out to obtain a refined mixed monomer with a purity of 99.97%. Under nitrogen protection at a flow rate of 0.7 L / min, 100 g of refined mixed monomers, 0.035 g of titanium diacene catalyst, and 160 g of toluene were added to a reactor. The reaction temperature was controlled at 80 °C, the stirring rate at 280 r / min, and the reaction time at 7.5 h for addition polymerization to obtain crude acenaphthene-fluorinated copolymer hydrocarbon resin. The crude product was washed three times with deionized water, each time using 0.5 times the mass of the crude product, to remove the catalyst. Subsequently, it was passed through a cation exchange resin for 3.5 h to remove metal ions. Finally, it was subjected to vacuum devolatilization at 150 °C and a vacuum degree of 0.095 MPa for 4.5 h to remove organic solvents and residual monomers, yielding crude hydrocarbon resin. The crude product was cooled to room temperature, pulverized, and sieved to obtain 85 kg of finished hydrocarbon resin with a particle size of 150 mesh, with a yield of 85%.

[0050] The performance of the hydrocarbon resin prepared in Example 3 was tested, and the results are as follows: dielectric constant (Dk, 10GHz): 2.65; dielectric loss (Df, 10GHz): 0.0033; purity: 99.993%; Fe content: 0.5ppm, Cu content: 0.3ppm, Na content: 0.2ppm, total metal ion content 1.0ppm < 3ppm; glass transition temperature (Tg): 238℃; coefficient of thermal expansion (CTE, 25-200℃): 46ppm / ℃; water absorption rate (25℃, 24h): 0.035%; hydrophobicity test showed that the resin water contact angle ≥120°, and the hydrophobicity was further improved compared with Example 1 containing 10% fluorine; molecular weight distribution (PDI): 2.3; good processing performance; flame retardant rating: UL94 V-0.

[0051] Specifically, increasing the proportion of fluorinated monomers to 15% further optimizes the hydrophobicity (water contact angle, water absorption rate) of the resin, slightly improves dielectric properties and heat resistance, and has no obvious side reactions, resulting in good processing performance. The synergistic effect between acenaphthene and fluorinated monomers is significant, proving that fluorinated monomers can achieve synergistic optimization of "hydrophobicity + dielectric properties + heat resistance" within the range of 5%-20%. At the same time, the fluorinated monomers prepared by the DA reaction have stable purity, can be adapted to the preparation requirements of mixed monomers with different proportions, and have good copolymerization compatibility with acenaphthene.

[0052] Example 4: Preparation and properties of acenaphthene-based hydrocarbon resin with 5% fluorinated monomer. 95g of acenaphthene monomer (purity 99.95%) was mixed with 5g of the fluorinated monomer (5-(pentafluorophenyl)-2-norbornene) prepared above (fluorinated monomer content 5%). The distillation temperature was controlled at 115℃ and the vacuum degree was 0.07MPa. Three-stage distillation was carried out to obtain a refined mixed monomer with a purity of 99.95%. Under nitrogen protection at a flow rate of 0.6 L / min, 100 g of refined mixed monomers, 0.02 g of zirconium thiocene catalyst, and 120 g of cyclohexane were added to a reactor. The reaction temperature was controlled at 70 °C, the stirring rate at 230 r / min, and the reaction time at 8 h for addition polymerization to obtain crude acenaphthene-fluorinated copolymer hydrocarbon resin. The crude product was washed four times with deionized water, each time using 0.5 times the mass of the crude product, to remove the catalyst. Subsequently, it was passed through a cation exchange resin for 2.5 h to remove metal ions. Finally, it was degassed under reduced pressure at 140 °C and a vacuum of 0.09 MPa for 6 h to remove organic solvents and residual monomers, yielding crude hydrocarbon resin. The crude product was cooled to room temperature, pulverized, and sieved to obtain 88 g of finished hydrocarbon resin with a particle size of 120 mesh, with a yield of 88%.

[0053] Performance test results: Dk (10GHz) = 2.85; Df (10GHz) = 0.0039; Purity = 99.991%; Total metal ion content = 1.5ppm; Tg = 232℃; CTE = 52ppm / ℃; Water absorption rate = 0.048%; Water contact angle = 112°; PDI = 2.1; Flame retardant rating UL94 V-0, which meets the scope of protection of the claims and is suitable for conventional M9 grade copper clad laminate scenarios.

[0054] Comparative Example 1: The performance of conventional resin was tested using existing conventional acenaphthene homopolymer hydrocarbon resin (commercially available, without the introduction of fluorine-containing monomers, and without the purification and polymerization process of this invention). The performance test results are as follows: Dk (10GHz) = 3.2, Df (10GHz) = 0.008; purity = 99.8%; total metal ion content = 8ppm; Tg = 215℃; CTE = 63ppm / ℃; water absorption rate = 0.13%, water contact angle 82°, indicating poor hydrophobicity; molecular weight distribution (PDI) = 2.8, indicating embrittlement and poor processing performance.

[0055] The comparison shows that the acenaphthene-fluorinated copolymer hydrocarbon resin and composition prepared by this invention, which prepares high-purity fluorinated monomers through in-situ DA reaction and then modifies them by addition copolymerization with acenaphthene, are significantly superior to existing conventional acenaphthene hydrocarbon resins in terms of dielectric properties, purity, heat resistance, dimensional stability, hydrophobicity, and processing performance. At the same time, it solves the technical pain points of existing acenaphthene monomer purification difficulties, difficulty in obtaining dedicated fluorinated monomers, and substandard purity, as well as the problem of immature copolymerization process of acenaphthene and fluorinated monomers.

[0056] In summary, the acenaphthene-based fluorinated hydrocarbon resin for M9 grade copper clad laminates and its preparation method utilizes an in-situ DA reaction to prepare high-purity fluorinated monomers. The main molecular chain is a saturated carbon chain formed by the addition polymerization of acenaphthene and 5-(pentafluorophenyl)-2-norbornene. The naphthalene ring skeleton of the acenaphthene unit is spaced apart in the main chain, and the pentafluorophenyl substituents are connected to the side chains of the norbornene unit, ensuring uniform dispersion of the fluorinated groups and fully leveraging the low dielectric and high hydrophobic effects. Simultaneously, the naphthalene ring skeleton enhances molecular rigidity and heat resistance, while the acenaphthene unit provides a rigid naphthalene ring skeleton, significantly improving the resin's glass transition temperature and heat resistance. Furthermore, its non-polar structure further reduces the resin's dielectric loss and improves its dimensional stability. The pentafluorophenyl possesses extremely strong hydrophobicity and low polarity, effectively reducing the resin's surface energy, improving hydrophobicity, and reducing water absorption, while further optimizing the resin's dielectric properties. Moreover, its cyclic olefin structure has excellent compatibility with acenaphthene, avoiding phase separation during copolymerization.

[0057] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a acenaphthene-based fluorocarbon resin, characterized in that, The process includes the following steps: S1, Preparation of fluorinated monomers: Fresh cyclopentadiene is obtained by cracking and distilling dicyclopentadiene. Pentafluorostyrene and fresh cyclopentadiene are mixed at a molar ratio of 1:1.2-1.

5. After DA reaction, post-treatment and purification, 5-(pentafluorophenyl)-2-norbornene with a purity ≥99.95% is obtained, which is the fluorinated monomer; S2, Preparation of mixed monomers: Acenamethanone monomer and fluorinated monomers are mixed and purified to obtain a purified mixed monomer with a purity ≥99.95%; S3, Polymerization reaction: Under inert gas protection, the purified mixed monomers, metallocene catalyst and organic solvent are subjected to addition polymerization to obtain a crude product; S4, Purification treatment: The crude product is purified to obtain a hydrocarbon resin with a purity ≥99.99%; S5, Post-treatment: The purified hydrocarbon resin is processed into a finished resin.

2. The preparation method according to claim 1, characterized in that, The chemical reaction formula for the DA reaction in S1 is: 。 3. The preparation method according to claim 1, characterized in that, The DA reaction in S1 is a Diels-Alder [4+2] cycloaddition reaction, with a reaction temperature of 80–120°C, a stirring rate of 150–250 r / min, a reaction time of 6–12 h, and a reaction solvent of toluene or a solvent-free bulk reaction. The post-treatment and purification in S1 include cooling the reaction solution to room temperature, removing unreacted cyclopentadiene and solvent under reduced pressure, and purifying the crude product by vacuum distillation or recrystallization in a mixed solvent of ethanol / hexane. The vacuum distillation temperature is 110–120°C, and the vacuum degree is not higher than 1 mmHg.

4. The preparation method according to claim 1, characterized in that, The polymerization reaction in S3 includes: in a reactor, controlling the reaction temperature at 60–90°C, the stirring rate at 200–300 r / min, and the reaction time at 5–9 h; the chemical reaction formula for the polymerization reaction is: R1, R2, and R3 are each independently selected from any one of hydrogen atoms, methyl, ethyl, trifluoromethyl, allyl, and pentafluoroethyl; the degree of polymerization m of the acenaphthene unit ranges from 30 to 150, the degree of polymerization n of the fluorinated monomer unit ranges from 20 to 80, and m:n = 1.5:1 to 7.5:

1.

5. The preparation method according to claim 1, characterized in that, The inert gas in S3 is either nitrogen or argon, and the flow rate of the inert gas is 0.5 to 1 L / min; the organic solvent is either cyclohexane or toluene, and the amount of organic solvent used is 1 to 2 times the mass of the mixed monomers; the metallocene catalyst is either zirconium dicene or titanocene, and the amount of metallocene catalyst used is 0.01 to 0.05% of the total monomer mass.

6. The preparation method according to claim 1, characterized in that, The purification process in S4 includes sequential water washing, ion exchange, and vacuum devolatilization. The water washing is performed at least three times, with each wash using 0.5 times the mass of the crude product. The ion exchange uses a cation exchange resin and the exchange time is 2–4 hours. The vacuum devolatilization process is performed at a temperature of 130–160°C and a vacuum degree of 0.09–0.1 MPa.

7. The preparation method according to claim 1, characterized in that, The post-processing in S5 includes cooling, crushing, and sieving; the particle size of the finished resin is 100-200 mesh.

8. A acenaphthene-based fluorocarbon resin, characterized in that, The acenaphthene-based fluorocarbon resin has an alternating or random distribution of acenaphthene units and fluorinated monomer units in its molecular structure. The degree of polymerization (m) of the acenaphthene unit ranges from 30 to 150, and the degree of polymerization (n) of the fluorinated monomer unit ranges from 20 to 80, with a m:n ratio of 1.5:1 to 7.5:

1. The dielectric constant (Dk) of the acenaphthene-based fluorocarbon resin in the 10 GHz band is 2.5 to 2.9, and the dielectric loss (Df) is ≤0.

004. The purity of the acenaphthene-based fluorocarbon resin is ≥99.99%, and the total metal ion content is <3 ppm. The glass transition temperature (Tg) of the acenaphthene-based fluorocarbon resin is ≥230℃, the coefficient of thermal expansion (CTE) is 35 to 55 ppm / ℃, the water absorption rate is ≤0.05%, the water contact angle is ≥110°, and the molecular weight distribution (PDI) is 1.8 to 2.

5.

9. A acenaphthene-based fluorocarbon resin composition, characterized in that, The product comprises the following components in parts by weight: 60-80 parts of acenaphthene-based fluorocarbon resin as described in claim 8, 10-20 parts of benzoxazine resin, 5-15 parts of low-dielectric filler, 0.5-2 parts of curing accelerator, and 0.1-1 parts of coupling agent; wherein the low-dielectric filler is hollow glass microspheres or porous SiO2, the curing accelerator is imidazole, and the coupling agent is silane coupling agent KH-560.

10. The acenaphthene-based fluorocarbon resin composition according to claim 9, characterized in that, The acenaphthene-based fluorocarbon resin composition has a dielectric constant Dk of 2.6–3.0 and a dielectric loss Df ≤ 0.0045 in the 10 GHz band; the glass transition temperature Tg of the acenaphthene-based fluorocarbon resin composition is ≥ 240 °C, the coefficient of thermal expansion CTE is ≤ 50 ppm / °C, the UL94 flame retardant rating is V-0, the water absorption rate is ≤ 0.55%, and the water contact angle is ≥ 110°.