A method for preparing a modified liquid hydrocarbon polymer, resin composition and use thereof

Abstract

The present application relates to a kind of preparation method of modified liquid hydrocarbon polymer, resin composition and its application.The present application utilizes carboxylation liquid hydrocarbon polymer and esterification reaction is carried out with fluorine-containing alkyl alcohol to obtain modified liquid hydrocarbon polymer, the preparation method not only realizes the covalent bond of fluorine-containing group and liquid hydrocarbon polymer, but also generates ester group, improves the interface compatibility of hydrocarbon polymer and polyphenyl ether, polar material, further reduces dielectric loss simultaneously;The present application constructs the resin composition with excellent dielectric property, and gives consideration to dielectric property, thermal stability and copper foil adhesion and low thermal expansion coefficient, has great application value in high frequency and high speed copper clad plate field.

Description

Technical Field

[0001] This invention belongs to the field of materials science and engineering technology, specifically relating to a modified liquid hydrocarbon polymer, its preparation method, resin composition and its application. Background Technology

[0002] With the rise of strategic emerging fields such as autonomous driving, 5G+communications, and artificial intelligence, the electronic information industry is developing towards higher frequencies and higher speeds. Copper-clad laminates (CCLs), as crucial carriers for signal transmission and reception and data transmission, rely heavily on their dielectric resin materials for comprehensive performance, placing higher demands on dielectric resin manufacturers. Traditional epoxy resins, due to their excessively high dielectric loss, cannot meet the demands of high-frequency and high-speed CCLs. Liquid hydrocarbon polymers possess excellent dielectric properties, water resistance, and good processability, making hydrocarbon CCLs the most commonly used commercial product in high-frequency and high-speed applications. However, because the main chain of liquid hydrocarbon polymers lacks polar groups, their compatibility with polar materials is poor, leading to problems such as poor filler dispersion, low copper foil peel strength, and easy delamination of composite heat-resistant resins.

[0003] Chinese patent CN115651128A discloses a hydrocarbon resin polymer and a method for preparing a copper-clad laminate containing it. First, styrene, butadiene, and propylene monomers are added to a reaction device to undergo anionic polymerization to obtain a liquid hydrocarbon polymer with a number-average molecular weight of 700-2000. This liquid hydrocarbon polymer is used as the dielectric resin material of the copper-clad laminate. The wettability is improved by relying on the lower molecular weight. However, the liquid hydrocarbon polymer in this scheme is a non-polar polymer, which has poor compatibility with fillers, insufficient copper foil peel strength, and poor overall stability of the copper-clad laminate. Chinese patent CN104845366A discloses a halogen-free resin composition and its uses. The composition involves mixing a liquid hydrocarbon polymer, allyl-modified benzoxazine resin, allyl-modified polyphenylene ether resin, an initiator, inorganic fillers, and a flame retardant to prepare a prepreg and a laminate. The composition utilizes the carbon-carbon double bonds of each resin component for co-curing, resulting in good dielectric properties and heat resistance. However, the liquid hydrocarbon polymer has poor compatibility with benzoxazine, polyphenylene ether, and inorganic fillers, leading to a risk of delamination and cracking of the prepared laminate under high-temperature processing. Chinese patent CN111378243A discloses a semi-cured sheet hydrocarbon composition of a multifunctional modified resin blend. The multifunctional modified resin is a mixture of hydrocarbon polymers and modified hydrocarbon polymers. The modified hydrocarbon polymers are hydroxyl-terminated and polyether-modified hydrocarbon polymers. The hydrocarbon polymers include liquid hydrocarbon polymers. By polarizing the hydrocarbon polymers, the filler dispersibility, thermal stability of the copper clad laminate, and peel strength are further improved. However, the introduction of polar groups has an adverse effect on dielectric loss. Therefore, the amount of modified hydrocarbon polymers added does not exceed 25% of the total resin, and its effect on improving the overall performance of the copper clad laminate is limited. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing modified liquid hydrocarbon polymers, a resin composition, and its applications. Through esterification, chemical bonding is achieved between fluorinated alkyl alcohols and carboxylated liquid hydrocarbon polymers, constructing a resin composition with excellent dielectric properties. This composition achieves good interfacial interaction with inorganic fillers, copper foil, and polyphenylene ether resins, balancing dielectric properties, thermal stability, copper foil adhesion, and a low coefficient of thermal expansion, thereby improving the overall performance of copper-clad laminates.

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

[0006] A method for preparing a modified liquid hydrocarbon polymer, wherein the modified liquid hydrocarbon polymer is obtained by esterification reaction of a carboxylated liquid hydrocarbon polymer and a fluorinated alkyl alcohol.

[0007] As a preferred embodiment, the esterification reaction conditions of the carboxylated liquid hydrocarbon polymer and the fluorinated alkyl alcohol are as follows: the carboxylated liquid hydrocarbon polymer is added to toluene and stirred to dissolve; the temperature is controlled at 20-30°C, the fluorinated alkyl alcohol is added and stirred, and after reacting with the catalyst for 20-24 hours, the reaction solution is added to ethanol to precipitate, the upper layer solution is poured off, and the precipitate is washed with ethanol and rotary evaporated to obtain the modified liquid hydrocarbon polymer.

[0008] Preferably, the fluorinated alkyl alcohol is tridecylfluorooctyl alcohol or perfluoroalkyl ethanol, the catalyst is 4-dimethylaminopyridine, and the molar ratio of the catalyst to the fluorinated alkyl alcohol is 3-5:100.

[0009] Preferably, the carboxylated liquid hydrocarbon polymer is obtained by grafting thiocarboxylic acid onto a liquid hydrocarbon polymer via a thiol-ene click chemical reaction chain.

[0010] Preferably, the grafting rate of the carboxylated liquid hydrocarbon polymer is 5-10%; the mercaptocarboxylic acid is one or more of mercaptoacetic acid, mercaptopropionic acid, and mercaptohexanoic acid.

[0011] If the grafting rate is too low, it will reduce the amount of fluorinated alkyl alcohols grafted in the esterification reaction, affecting the modification effect and failing to effectively reduce the dielectric loss of the resin composition; if the grafting rate is too high, the polar carboxyl groups will interact and form a physical gel in the solution system, affecting the industrial production process.

[0012] Preferably, the liquid hydrocarbon polymer is one or a mixture of two of liquid polybutadiene and liquid styrene-butadiene copolymer; the number average molecular weight of the liquid hydrocarbon polymer is 4,000 to 10,000; and the 1,2 structure content is 50 to 90 wt% based on the total content of butadiene structural units.

[0013] Too low a molecular weight leads to the introduction of a large amount of butyllithium initiator during polymerization, significantly increasing costs; too high a molecular weight increases the entanglement of macromolecular chains, reducing the dispersion effect of modified liquid hydrocarbon polymers with polyphenylene ether and fillers; too low a 1,2 structure reduces the reaction efficiency of mercaptocarboxylic acids in click chemistry. A 1,2 structure higher than 90% does not significantly improve the grafting rate of mercaptocarboxylic acids in click chemistry, and it is difficult to increase the 1,2 structure to above 90% under current technology.

[0014] Preferably, the preparation method of the carboxylated liquid hydrocarbon polymer specifically includes the following steps:

[0015] (1) Preparation of liquid hydrocarbon polymer

[0016] The liquid hydrocarbon polymer includes liquid polybutadiene and liquid styrene-butadiene copolymer;

[0017] Preparation of liquid polybutadiene: Cyclohexane, butadiene monomer, and polar regulator are added to a reactor, stirred and heated, and an initiator is added to initiate the polymerization reaction. After termination, the liquid hydrocarbon polymer is obtained by metal removal treatment and rotary evaporation.

[0018] Preparation of liquid styrene-butadiene copolymer: A three-step feeding method was adopted. Cyclohexane and a measured amount of styrene were added to the reactor, stirred and heated. An initiator was added to react and obtain a first-stage active product. A polar modifier and butadiene were added to react and obtain a second-stage active product. The reaction was terminated after adding a measured amount of styrene. After metal removal treatment and rotary evaporation, liquid styrene-butadiene copolymer was obtained.

[0019] (2) Preparation of carboxylated liquid hydrocarbon polymers:

[0020] Cyclohexane and liquid hydrocarbon polymer were added to the reactor, stirred and dissolved, and then heated to 60-90°C. Thiocarboxylic acid and initiator were added, and the mixture was stirred and reacted before being cooled to room temperature. After precipitation in ethanol, the mixture was washed and rotary evaporated to obtain carboxylated liquid hydrocarbon polymer.

[0021] In step (1), the polarity modifier is bis(tetrahydrofurfuryl)propane and the initiator is n-butyllithium; in step (2), the initiator is benzoyl peroxide.

[0022] The present invention also provides a resin composition comprising the above-described modified liquid hydrocarbon polymer, wherein the raw materials of the resin composition are, by weight:

[0023] Modified liquid hydrocarbon polymer: 25-50 parts;

[0024] Vinyl polyphenylene ether: 25-50 parts;

[0025] Inorganic filler: 30-60 parts;

[0026] Crosslinking agent: 3-6 parts;

[0027] Flame retardant: 10-20 parts.

[0028] Preferably, the inorganic filler is one or more of silicon dioxide, titanium dioxide, aluminum oxide, silicon nitride, and hollow glass microspheres; the crosslinking agent is one or more of dicumyl peroxide, diisopropylbenzene hydroperoxide, di-tert-butyldiisopropylbenzene hydroperoxide, and benzoyl peroxide.

[0029] In addition, the present invention also provides the application of the above-mentioned resin composition for preparing laminates for copper-clad laminates.

[0030] Preferably, the laminate is prepared by the following steps:

[0031] (i) A resin composition containing a modified liquid hydrocarbon polymer is added to toluene and dispersed evenly to obtain a prepreg; the mass ratio of the resin composition to toluene in the prepreg is 66 to 186: 100.

[0032] (ii) Impregnate electronic fiberglass cloth in prepreg and dry to obtain a copper-clad laminate prepreg; the drying temperature is 125-135℃ and the drying time is 5-15 minutes.

[0033] (iii) A number of prepreg sheets are stacked, and copper foil is applied to the top and bottom surfaces. The laminate is obtained by high-temperature lamination. The pressure of the high-temperature lamination process is 2-4 MPa, the temperature is 190-240°C, and the lamination time is 2-5 hours.

[0034] The beneficial effects of this invention are as follows:

[0035] This invention utilizes the esterification reaction between the carboxyl groups in a carboxylated liquid hydrocarbon polymer and the hydroxyl groups in a fluorinated alkyl alcohol. This preparation method not only achieves covalent bonding between the fluorinated groups and the liquid hydrocarbon polymer but also generates ester groups. The ester groups and residual carboxyl groups improve compatibility with vinyl polyphenylene ether, solving the problem of delamination and cracking in hydrocarbon copper-clad laminates; they strengthen the interfacial interaction with inorganic fillers, effectively limiting the thermal motion of resin macromolecules and reducing the coefficient of thermal expansion of the copper-clad laminate; and they form hydrogen bonds with the surface-active groups of the copper foil, improving peel strength. The fluorinated groups can improve the heat resistance and hydrophobicity of the liquid hydrocarbon polymer, offsetting the high dielectric loss caused by the ester groups and residual carboxyl groups. By constructing a resin composition with excellent dielectric properties, it balances dielectric performance, thermal stability, copper foil adhesion, and a low coefficient of thermal expansion, making it highly valuable for applications in high-frequency and high-speed copper-clad laminates. Attached Figure Description

[0036] Figure 1 This is the 1H NMR spectrum of the liquid styrene-butadiene copolymer obtained by this invention;

[0037] Figure 2This is the 1H NMR spectrum of the carboxylated liquid styrene-butadiene copolymer prepared in Example 1 of this invention;

[0038] Figure 3 This is the 1H NMR spectrum of the modified liquid styrene-butadiene copolymer prepared in Example 1 of this invention;

[0039] Figure 4 These are the GPC spectra of the carboxylated liquid styrene-butadiene copolymer and the modified liquid styrene-butadiene copolymer prepared in Example 1 of this invention. Detailed Implementation

[0040] The technical solution of the present invention will be further described in detail below through embodiments. These embodiments are for illustrative purposes only and are not intended to limit the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] Unless otherwise specified, the experimental methods described in the embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0042] The mercaptopropionic acid, mercaptohexanoic acid, tridecafluorooctyl alcohol, perfluoroalkyl ethanol, 4-dimethylaminopyridine, and dicumyl peroxide used in this invention were all purchased from Beijing Innocare Technology Co., Ltd.; silica was purchased from Suzhou Jinyi New Material Technology Co., Ltd., with a particle size of 5 μm; titanium dioxide was purchased from Shandong Guoci Functional Materials Co., Ltd., with a particle size of 7.5 μm; hollow glass microspheres were purchased from Zhengzhou Shenglete Hollow Microsphere New Material Co., Ltd., with a particle size of 10 μm; and vinyl polyphenylene ether was purchased from SABIC, brand name SA9000, with a molecular weight of 1000.

[0043] Preparation of liquid styrene-butadiene copolymer

[0044] 5 L of cyclohexane was added to a reactor that had been repeatedly purged with nitrogen, and the temperature was raised to 45 °C. 75 g of styrene and 37 ml of n-butyllithium (2.2 M) were added, and the reaction was allowed to proceed for 45 min. 8 g of bis(tetrahydrofurfurylene) and 350 g of butadiene were then added, and the reaction was allowed to proceed for 60 min. 75 g of styrene was added, and the reaction was continued for another 45 min before being terminated with saturated carbonic acid. The terminated solution was then added to deionized water, stirred thoroughly, and centrifuged to obtain a pure solution free of metals. After rotary evaporation, a liquid styrene-butadiene copolymer was obtained with a number-average molecular weight of 6800. The 1H NMR spectrum of the prepared liquid styrene-butadiene copolymer is shown below. Figure 1 As shown, the content of structure 1,2 was found to be 60% after analysis. The analytical calculation method is as follows:

[0045] 1,2 Structure content = {A(c) / [A(c)+A(a)]}×100%

[0046] A(c) represents the peak area of ​​the two H atoms on the =CH2 in the 1,2 double bond;

[0047] A(a) represents the peak area of ​​the two H atoms in the -CH=CH- double bond of the 1,4 structure. Example 1

[0048] The preparation method of the modified liquid hydrocarbon polymer is as follows:

[0049] (1) In a reaction flask equipped with a condenser and a nitrogen atmosphere, 1 L of cyclohexane and 100 g of liquid styrene-butadiene copolymer were added. After stirring and dissolving, the mixture was heated to 80 °C. Then, 10 g of mercaptopropionic acid and 0.1 g of benzoyl peroxide were added. After stirring for 6 hours, the mixture was cooled to room temperature. The resulting product was precipitated in 3 times its volume of ethanol, washed, and rotary evaporated to obtain a carboxylated liquid hydrocarbon polymer. The grafting rate of mercaptopropionic acid was calculated to be 8% by weighing. The 1H NMR spectrum of the product is shown below. Figure 2 As shown, the peak at chemical shift 2.76 is the shift peak of H on the methylene-CH2 group adjacent to the sulfur atom at positions d and e, and the peak at chemical shift 2.65 is the shift peak of H on the methylene-CH2 group adjacent to the carbonyl group, indicating that mercaptopropionic acid has been successfully grafted onto the liquid styrene-butadiene copolymer.

[0050] (2) In a reaction flask under a nitrogen atmosphere, 100g of the above carboxylated liquid styrene-butadiene copolymer was added to 1L of toluene and stirred thoroughly to dissolve. The temperature was controlled at 25±2℃. 15g of tridecafluorooctol was added and stirred thoroughly. 0.2g of 4-dimethylaminopyridine was added and the reaction was carried out for 22 hours. The mixture was then cooled to room temperature. The reaction solution was added to 5 times its volume of ethanol to precipitate the copolymer. After pouring off the supernatant, the copolymer was washed with ethanol to remove unreacted tridecafluorooctol and residual catalyst. The modified liquid styrene-butadiene copolymer was obtained by rotary evaporation. The grafting rate of tridecafluorooctol was calculated to be 13.4% by gravimetric method. The 1H NMR spectrum of the obtained product is shown below. Figure 3 As shown, the peak at chemical shift 4.1 corresponds to the shift peak of the H atom on the methylene-CH2 group adjacent to the oxygen atom on the ester group, indicating that tridecafluorooctyl alcohol underwent an esterification reaction with the carboxylated liquid styrene-butadiene copolymer. Meanwhile, the GPC spectrum of the obtained product is shown below. Figure 4 As shown, the GPC peak of the modified liquid styrene-butadiene copolymer shifted to the left, the elution time shifted from 8.6 min for the carboxylated liquid styrene-butadiene copolymer to 8.4 min, and the number-average molecular weight increased from 6800 to 7700, which also indicates that tridecafluorooctanol and the carboxylated liquid styrene-butadiene copolymer underwent an esterification reaction.

[0051] The resin composition containing the modified liquid hydrocarbon polymer comprises, by weight, the following raw materials: modified liquid styrene-butadiene copolymer: 50 parts; vinyl polyphenylene ether: 50 parts; silica: 50 parts; dicumyl peroxide crosslinking agent: 5 parts; decabromodiphenyl ethane flame retardant: 15 parts. Example 2

[0052] The preparation method of the modified liquid hydrocarbon polymer is as follows:

[0053] (1) In a reaction flask equipped with a condenser and a nitrogen atmosphere, 1L of cyclohexane and 100g of liquid styrene-butadiene copolymer were added. After stirring and dissolving, the mixture was heated to 80°C. Then, 8g of mercaptopropionic acid and 0.1g of benzoyl peroxide were added. After stirring and reacting for 6 hours, the mixture was cooled to room temperature. The resulting product was placed in 3 times the amount of ethanol for precipitation, washed, and rotary evaporated to obtain a carboxylated liquid hydrocarbon polymer. The grafting rate of mercaptopropionic acid was calculated to be 6% by weighing.

[0054] (2) In a reaction flask under a nitrogen atmosphere, 100g of the above carboxylated liquid styrene-butadiene copolymer was added to 1L of toluene and stirred thoroughly to dissolve. The temperature was controlled at 25±2℃. 13g of tridecafluorooctyl alcohol was added and stirred thoroughly. 0.13g of 4-dimethylaminopyridine was added and the reaction was carried out for 22 hours. The mixture was then cooled to room temperature. The reaction solution was added to 5 times its volume of ethanol to precipitate the copolymer. After pouring off the supernatant, the copolymer was washed with ethanol to remove unreacted tridecafluorooctyl alcohol and residual catalyst. The modified liquid styrene-butadiene copolymer was obtained by rotary evaporation. The grafting rate of tridecafluorooctyl alcohol was calculated to be 10.7% by weighing.

[0055] The resin composition containing the modified liquid hydrocarbon polymer comprises, by weight, the following raw materials: modified liquid styrene-butadiene copolymer: 50 parts; vinyl polyphenylene ether: 50 parts; silica: 50 parts; dicumyl peroxide crosslinking agent: 5 parts; decabromodiphenyl ethane flame retardant: 15 parts. Example 3

[0056] The preparation method of the modified liquid hydrocarbon polymer is as follows:

[0057] (1) In a reaction flask equipped with a condenser and a nitrogen atmosphere, 1L of cyclohexane and 100g of liquid styrene-butadiene copolymer were added. After stirring and dissolving, the mixture was heated to 80°C. Then, 12g of mercaptopropionic acid and 0.1g of benzoyl peroxide were added. After stirring and reacting for 6 hours, the mixture was cooled to room temperature. The resulting product was precipitated in 3 times the amount of ethanol, washed, and rotary evaporated to obtain a carboxylated liquid hydrocarbon polymer. The grafting rate of mercaptopropionic acid was calculated to be 10% by weighing.

[0058] (2) In a reaction flask under a nitrogen atmosphere, 100g of the above carboxylated liquid styrene-butadiene copolymer was added to 1L of toluene and stirred thoroughly to dissolve. The temperature was controlled at 25±2℃. 20g of tridecafluorooctol was added and stirred thoroughly. 0.34g of 4-dimethylaminopyridine was added and the reaction was carried out for 22 hours. The mixture was then cooled to room temperature. The reaction solution was added to 5 times its volume of ethanol to precipitate the copolymer. After pouring off the supernatant, the copolymer was washed with ethanol to remove unreacted tridecafluorooctol and residual catalyst. The modified liquid styrene-butadiene copolymer was obtained by rotary evaporation. The grafting rate of tridecafluorooctol was calculated to be 18.5% by weighing.

[0059] The resin composition containing the modified liquid hydrocarbon polymer comprises, by weight, the following raw materials: modified liquid styrene-butadiene copolymer: 50 parts; vinyl polyphenylene ether: 50 parts; silica: 50 parts; dicumyl peroxide crosslinking agent: 5 parts; decabromodiphenyl ethane flame retardant: 15 parts. Example 4

[0060] The preparation method of the modified liquid hydrocarbon polymer is as follows:

[0061] (1) In a reaction flask equipped with a condenser and a nitrogen atmosphere, 1L of cyclohexane and 100g of liquid styrene-butadiene copolymer were added. After stirring and dissolving, the mixture was heated to 80°C. Then, 12.5g of mercaptohexanoic acid and 0.12g of benzoyl peroxide were added. After stirring and reacting for 6 hours, the mixture was cooled to room temperature. The resulting product was placed in 3 times the amount of ethanol for precipitation, washed, and rotary evaporated to obtain a carboxylated liquid hydrocarbon polymer. The grafting rate of mercaptohexanoic acid was calculated to be 10% by weighing.

[0062] (2) In a reaction flask under a nitrogen atmosphere, 100g of the above carboxylated liquid styrene-butadiene copolymer was added to 1L of toluene and stirred thoroughly to dissolve. The temperature was controlled at 25±2℃. 6.5g of perfluoroalkyl ethanol was added and stirred thoroughly. 0.35g of 4-dimethylaminopyridine was added and the reaction was carried out for 22 hours. The mixture was then cooled to room temperature. The reaction solution was added to 5 times its volume of ethanol to precipitate the copolymer. After pouring off the supernatant, the copolymer was washed with ethanol to remove unreacted perfluoroalkyl ethanol and residual catalyst. The modified liquid styrene-butadiene copolymer was obtained by rotary evaporation. The grafting rate of perfluoroalkyl ethanol was calculated to be 5% by weighing.

[0063] The resin composition containing the modified liquid hydrocarbon polymer comprises, by weight, the following raw materials: modified liquid styrene-butadiene copolymer: 50 parts; vinyl polyphenylene ether: 50 parts; silica: 50 parts; dicumyl peroxide crosslinking agent: 5 parts; decabromodiphenyl ethane flame retardant: 15 parts. Example 5

[0064] The difference between Example 5 and Example 1 is that the modified liquid hydrocarbon polymer resin composition, by weight, comprises the following raw materials:

[0065] Modified liquid styrene-butadiene copolymer: 50 parts;

[0066] Vinyl polyphenylene ether: 25 parts;

[0067] Silica: 37 parts;

[0068] Dicumyl peroxide crosslinking agent: 5 parts;

[0069] Decabromodiphenyl ethane flame retardant: 15 parts;

[0070] Everything else is the same as in Example 1. Example 6

[0071] The difference between Example 6 and Example 1 is that the modified liquid hydrocarbon polymer resin composition, by weight, comprises the following raw materials:

[0072] Modified liquid styrene-butadiene copolymer: 25 parts;

[0073] Vinyl polyphenylene ether: 50 parts;

[0074] Silica: 37 parts;

[0075] Dicumyl peroxide crosslinking agent: 5 parts;

[0076] Decabromodiphenyl ethane flame retardant: 15 parts;

[0077] Everything else is the same as in Example 1. Example 7

[0078] The difference between Example 7 and Example 1 is that the modified liquid hydrocarbon polymer resin composition, by weight, comprises the following raw materials:

[0079] Modified liquid styrene-butadiene copolymer: 50 parts;

[0080] Vinyl polyphenylene ether: 50 parts;

[0081] Hollow glass microspheres: 50 parts;

[0082] Dicumyl peroxide crosslinking agent: 6 parts;

[0083] Decabromodiphenyl ethane flame retardant: 10 parts;

[0084] Everything else is the same as in Example 1. Example 8

[0085] The difference between Example 8 and Example 1 is that the modified liquid hydrocarbon polymer resin composition, by weight, comprises the following raw materials:

[0086] Modified liquid styrene-butadiene copolymer: 50 parts;

[0087] Vinyl polyphenylene ether: 50 parts;

[0088] Silica: 25 parts;

[0089] Titanium dioxide: 25 parts;

[0090] Dicumyl peroxide crosslinking agent: 6 parts;

[0091] Decabromodiphenyl ethane flame retardant: 10 parts;

[0092] Everything else is the same as in Example 1.

[0093] Comparative Example 1

[0094] The liquid hydrocarbon polymer is not modified by carboxylation or fluorinated alkyl alcohols. The resin composition of the modified liquid hydrocarbon polymer is characterized in that, by weight, the raw materials include:

[0095] Liquid styrene-butadiene copolymer: 50 parts;

[0096] Vinyl polyphenylene ether: 50 parts;

[0097] Silica: 50 parts;

[0098] Dicumyl peroxide crosslinking agent: 5 parts;

[0099] Decabromodiphenyl ethane flame retardant: 15 parts.

[0100] Comparative Example 2

[0101] In a reaction flask equipped with a condenser and a nitrogen atmosphere, 1 L of cyclohexane and 100 g of liquid styrene-butadiene copolymer were added. After stirring and dissolving, the mixture was heated to 80 °C. Then, 10 g of mercaptopropionic acid and 0.1 g of benzoyl peroxide were added. After stirring and reacting for 6 hours, the mixture was cooled to room temperature. The resulting product was precipitated in 3 times its volume of ethanol, washed, and rotary evaporated to obtain a carboxylated liquid hydrocarbon polymer. The grafting rate of mercaptopropionic acid was calculated to be 8% by weighing. No further modification with fluorinated alkyl alcohols was performed.

[0102] The modified liquid hydrocarbon polymer resin composition comprises, by weight, the following raw materials:

[0103] Carboxylated liquid styrene-butadiene copolymer: 50 parts;

[0104] Vinyl polyphenylene ether: 50 parts;

[0105] Silica: 50 parts;

[0106] Dicumyl peroxide crosslinking agent: 5 parts;

[0107] Decabromodiphenyl ethane flame retardant: 15 parts.

[0108] Application examples

[0109] High-frequency, high-speed copper-clad laminates were prepared using the resin compositions from Examples 1-8 and Comparative Examples 1-2, respectively. The preparation methods were as follows:

[0110] (1) Add 150 parts of the resin composition to 100 parts of toluene and disperse evenly to obtain a prepreg;

[0111] (2) The electronic fiberglass cloth (Nittobo NEA2116 from Japan) was impregnated in the prepreg and dried at 130°C for 10 minutes to obtain the prepreg for high-frequency high-speed copper-clad laminate.

[0112] (3) Three layers of prepreg are stacked, and copper foil is applied to the top and bottom surfaces. The laminate is obtained by high-temperature lamination at a pressure of 3MPa and a temperature of 230℃ for 3 hours.

[0113] According to the IPC-TM650 testing method, the dielectric constant, dielectric loss, peel strength, thermal delamination time T288, water absorption rate, and Z-axis coefficient of thermal expansion (Z-CTE) of each laminate were tested. The results are shown in Table 1.

[0114] Table 1

[0115]

[0116] As shown in Table 1, the laminates prepared using the resin compositions containing the modified liquid hydrocarbon polymer of the present invention in Examples 1-8 have a dielectric loss of less than or equal to 0.002, achieving a good balance of dielectric properties, thermal stability, copper foil peel strength, and low coefficient of thermal expansion, resulting in excellent overall performance of the copper-clad laminates. In contrast, the liquid styrene-butadiene copolymer in Comparative Example 1, without in-chain carboxylation and fluorinated alkyl alcohol modification, has a higher dielectric loss and coefficient of thermal expansion, and insufficient thermal stability and peel strength. In Comparative Example 2, the liquid styrene-butadiene copolymer only underwent carboxylation modification, resulting in a higher dielectric loss of 0.004. In conclusion, the modified liquid hydrocarbon polymer and its compositions of the present invention have significant application value in the field of high-frequency and high-speed copper-clad laminates.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a modified liquid hydrocarbon polymer, characterized in that, The modified liquid hydrocarbon polymer is obtained by esterification of a carboxylated liquid hydrocarbon polymer with a fluorinated alkyl alcohol; the carboxylated liquid hydrocarbon polymer is obtained by grafting mercaptocarboxylic acid into a thiol-ene click chemical reaction chain of a liquid hydrocarbon polymer; the grafting rate of the carboxylated liquid hydrocarbon polymer is 5-10%; the liquid hydrocarbon polymer is one or a mixture of two of liquid polybutadiene and liquid styrene-butadiene copolymer.

2. The method for preparing the modified liquid hydrocarbon polymer according to claim 1, characterized in that, The esterification reaction conditions of carboxylated liquid hydrocarbon polymer and fluorinated alkyl alcohol are as follows: the carboxylated liquid hydrocarbon polymer is added to toluene and stirred to dissolve; the temperature is controlled at 20-30℃, the fluorinated alkyl alcohol is added and stirred, and after reacting for 20-24 hours with a catalyst, the reaction solution is added to ethanol to precipitate, the upper layer solution is poured off, and the precipitate is washed with ethanol and rotary evaporated to obtain the modified liquid hydrocarbon polymer.

3. The method for preparing the modified liquid hydrocarbon polymer according to claim 1, characterized in that, The thiocarboxylic acid is one or more of thioacetic acid, thiopropionic acid, and thiohexanoic acid.

4. The method for preparing the modified liquid hydrocarbon polymer according to claim 1, characterized in that, The number-average molecular weight of the liquid hydrocarbon polymer is 4,000 to 10,000; based on the total content of butadiene structural units, the 1,2 structure content is 50 to 90 wt%.

5. The method for preparing the modified liquid hydrocarbon polymer according to claim 2, characterized in that, The fluorinated alkyl alcohol is tridecylfluorooctyl alcohol or perfluoroalkyl ethanol, the catalyst is 4-dimethylaminopyridine, and the molar ratio of the catalyst to the fluorinated alkyl alcohol is 3-5:

100.

6. A resin composition, characterized in that, The resin composition comprises the modified liquid hydrocarbon polymer according to any one of claims 1 to 5, and the raw materials of the resin composition are, by weight: Modified liquid hydrocarbon polymer: 25-50 parts; Vinyl polyphenylene ether: 25-50 parts; Inorganic filler: 30-60 parts; Crosslinking agent: 3-6 parts; Flame retardant: 10-20 parts.

7. The resin composition according to claim 6, characterized in that, The inorganic filler is one or more of silicon dioxide, titanium dioxide, aluminum oxide, silicon nitride, and hollow glass microspheres; the crosslinking agent is one or more of dicumyl peroxide, diisopropylbenzene hydroperoxide, di-tert-butyldiisopropylbenzene hydroperoxide, and benzoyl peroxide.

8. An application of the resin composition of claim 6, characterized in that, The resin composition is used to prepare laminates for copper-clad laminates.

9. The application of the resin composition according to claim 8, characterized in that, The laminate is prepared by the following steps: (i) A resin composition containing a modified liquid hydrocarbon polymer is added to toluene and dispersed evenly to obtain a prepreg; the mass ratio of the resin composition to toluene in the prepreg is 66 to 186:

100. (ii) Impregnate electronic fiberglass cloth in prepreg and dry to obtain a copper-clad laminate prepreg; the drying temperature is 125-135℃ and the drying time is 5-15 minutes. (iii) A number of prepreg sheets are stacked, and copper foil is applied to the top and bottom surfaces. The laminate is obtained by high-temperature lamination. The pressure of the high-temperature lamination process is 2-4 MPa, the temperature is 190-240°C, and the lamination time is 2-5 hours.

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