High-ortho phenol-biphenylene phenolic resin and preparation method thereof

Abstract

The invention discloses high-ortho phenol-biphenylene phenolic resin and a preparation method thereof, and belongs to the technical field of phenolic resin synthesis. Phenol and 4, 4 '-biphenyl dimethyl ether are subjected to a condensation polymerization reaction under the action of a catalyst, a product obtained through the condensation polymerization reaction is washed and extracted, high-ortho phenol-biphenylene phenolic resin is recycled from an extracted organic phase, and raffinate is a water phase containing the catalyst; the catalyst is an acidic solution containing divalent metal sulfonate. The prepared high-ortho-position phenol-biphenylene phenolic resin has a higher melting point, the ortho-position substitution rate is larger than 70%, the high-ortho-position phenol-biphenylene phenolic resin has lower viscosity when being used for preparing epoxy resin, the catalyst, water washing liquid and removed phenol are recycled in the production process, and the method belongs to a clean phenolic resin production method.

Description

Technical Field

[0001] This invention relates to a phenolic resin, and more particularly to a high-ortho-phenol-biphenylphenolic resin and its preparation method, belonging to the field of phenolic resin synthesis technology. Background Technology

[0002] Epoxy resins are widely used in electronic packaging due to their excellent heat resistance, moisture resistance, and electrical properties. Epoxy molding compounds already account for over 90% of all electronic packaging materials, and this proportion will further increase with the development of various high-performance epoxy resins and their curing agents. In recent years, the high integration, miniaturization, and high reliability of electronic components have demanded that packaging resin materials possess characteristics such as high strength, high flowability, low water absorption, and high heat resistance. The high frequency and high speed characteristics of 5G communication also require resin materials with low dielectric constant (Dk) and low dielectric loss (Df). Introducing biphenyl, dicyclopentadiene, naphthalene, sulfone, and other structural elements into the epoxy resin backbone is one method to address these issues.

[0003] Phenol-biphenylene-phenolic resins with biphenyl structures can be used to synthesize corresponding epoxy resins and also as epoxy resin curing agents, thus obtaining high-performance cured products that meet the application requirements of high-end electronic packaging materials and have broad development prospects. Currently, the reported preparation methods for phenol-biphenylene-phenolic resins typically involve adding biphenyl dimethyl substitutes, phenol, a catalyst, and an acid to a reaction vessel and preparing them through addition and condensation reactions. Usually, the ortho-para substitution ratio of the product is not particularly outstanding. Patent WO2007063894A1 reports the preparation of biphenylene-phenolic resins using HBr as a catalyst. Compared with the product obtained using p-toluenesulfonic acid as a catalyst, it has a higher para (p) orientation, with 60% ≤ p ≤ 90%. The obtained product is prone to crystallization and has a high softening point, requiring further glycerol etherification to achieve better flowability, which does not meet the application requirements of high-end electronic packaging materials.

[0004] Molecular structure analysis indicates that improving the ortho-methylene bridging structure of phenolic resins can increase the curing speed and structural regularity of phenolic resins, thereby improving the application performance of the corresponding epoxy resins. However, the preparation of high-ortho-phenol-biphenylphenolic resins has not been reported. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing high ortho-substituted phenol-bisphenolene phenolic resin. This method features mild reaction conditions and a high ortho-substituted rate. Under the same degree of polymerization, the softening point of the obtained high ortho-substituted phenol-bisphenolene phenolic resin is lower than that of ordinary ortho- and para-substituted phenol-bisphenolene phenolic resin, and it exhibits better flowability.

[0006] The second objective of this invention is to provide a high ortho-phenol-biphenyl phenolic resin with an ortho-substitution rate of not less than 70%.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a method for preparing high-ortho-phenol-biphenylene aldehyde resin. The method involves carrying out a polycondensation reaction of phenol and 4,4'-biphenyl dimethyl ether under the action of a catalyst. The product obtained from the polycondensation reaction is washed with water and extracted to recover the high-ortho-phenol-biphenylene aldehyde resin from the extracted organic phase. The raffinate is an aqueous phase containing the catalyst. The catalyst is an acidic solution containing a divalent metal sulfonate.

[0008] The technical solution of this invention uses phenol and 4,4'-biphenyl dimethyl ether as raw materials. The active hydrogen on phenol and the methyl ether on 4,4'-biphenyl dimethyl ether are condensed by the removal of methanol in the form of small molecules to form phenol-biphenylene aldehyde resin. The condensation reaction on phenol mainly occurs at the ortho and para positions of the active hydrogen, while a small amount of less active meta-hydrogen also participates in the reaction, resulting in poor reaction selectivity. The key to this invention is the use of a special catalyst system that can improve the reaction selectivity between the ortho-active hydrogen of 4,4'-biphenyl dimethyl ether and phenol, thereby obtaining a high ortho-phenol-biphenylene aldehyde resin.

[0009] As a preferred embodiment, the catalyst has a pH ≤ 2. If the catalyst is too weakly acidic, the reaction will be too slow or not completed, and the selectivity of the ortho-reaction will be reduced.

[0010] As a preferred embodiment, the divalent metal ion in the divalent metal sulfonate is a transition metal ion or a magnesium ion, and the sulfonate ion is p-toluenesulfonate or methanesulfonate. Transition metal ions (e.g., zinc ions) and magnesium ions have an inducing effect on the ortho-condensation of phenol. Sulfonic acids are stronger than organic acids such as carboxylic acids, but weaker than inorganic acids such as hydrochloric acid and sulfuric acid. In the acidic solution system of this invention, the introduction of sulfonate ions can effectively exert its catalytic effect. While carboxylic acids and similar ions cannot promote the reaction, and strong inorganic acids can achieve the desired reaction effect, industrial applications require extremely high corrosion resistance from equipment, thus significantly increasing costs.

[0011] As a preferred embodiment, the amount of catalyst used is 1-10% of the mass of phenol. As a more preferred embodiment, the amount of catalyst used is 3-5% of the mass of phenol.

[0012] As a preferred embodiment, the molar ratio of phenol to 4,4'-biphenyl dimethyl ether is 2–20:1. As a more preferred embodiment, the molar ratio of phenol to 4,4'-biphenyl dimethyl ether is 2–10:1. The amount of phenol mainly affects the molecular weight distribution of the polymer product; the higher the amount of phenol, the narrower the molecular weight distribution. However, excessive phenol usage will increase recycling costs.

[0013] As a preferred embodiment, the conditions for the polycondensation reaction are: temperature of 40–150°C and time of 0.5–48 h. As a more preferred embodiment, the conditions for the polycondensation reaction are: temperature of 70–100°C and time of 1–4 h.

[0014] As a preferred embodiment, the extraction uses butanone, methyl isobutyl ketone and toluene as extractants.

[0015] As a preferred method, the process of recovering ortho-phenol-biphenyl phenolic resin from the extracted organic phase is as follows: the extracted organic phase is washed with water and the extractant and phenol are recovered by vacuum distillation, and then separated by elution to obtain high ortho-phenol-biphenyl phenolic resin.

[0016] The present invention also provides a high-ortho-phenol-biphenyl phenolic resin.

[0017] As a preferred embodiment, the ortho-substitution rate of the high-ortho-phenol-biphenol resin is not less than 70%.

[0018] The phenol-phenylene phenolic resin provided by this invention has the following general formula and connection method:

[0019]

[0020] The phenol-phenylene phenolic resin provided by the present invention contains all of the above (1), (2), and (3) linkage methods, among which (1) and (2) have a higher proportion of molecules linked at adjacent positions.

[0021] The present invention provides a method for preparing a high-ortho-phenol-biphenol-formaldehyde resin, comprising the following specific steps:

[0022] 1) Under nitrogen protection, phenol, diphenyl dimethyl ether, and catalyst are added to a reactor equipped with a stirrer, thermometer, and condenser, mixed thoroughly, and reacted at a set temperature; the molar ratio of phenol to diphenyl dimethyl ether is 2–20:1; the catalyst is an acidic solution of divalent metal sulfonate (pH≤2); the amount of catalyst is 1–10% of phenol; divalent metal ions such as magnesium ions, zinc ions, etc.; the reaction temperature is 40–150℃, and the time is 0.5–48h.

[0023] 2) After the reaction is completed, the aqueous phase containing the acidic catalyst is separated by water washing and extraction; the organic solvent phase is washed with water and the solvent and phenol are recovered by vacuum distillation to obtain crude resin; the organic solvent is one or more of butanone, methyl isobutyl ketone and toluene; the amount of the organic solvent is 10 to 300 wt% of the total weight of the added raw materials.

[0024] 3) The crude resin is separated by elution to obtain high-ortho-phenol-biphenyl phenol resin; the solvent used for elution is one or more of methanol, ethanol, isopropanol, toluene, n-hexane, ethyl acetate, dichloromethane, tetrahydrofuran, etc., and the mass of the solvent used for elution is 1 to 20 times the mass of the resin; after elution with organic solvent, filtration and depressurization are also included to remove the solvent.

[0025] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0026] The method for preparing high ortho-phenol-biphenyl-type phenolic resin provided by the present invention uses an acidic solution of divalent metal sulfonate (pH≤2) as the catalyst; and uses extraction to separate the aqueous phase containing the acid catalyst, which can effectively realize the recycling of the acid catalyst; and uses elution to separate the resin, which can obtain phenol-biphenyl-type phenolic resin with an ortho-substitution rate of not less than 70%.

[0027] The method for preparing high-ortho-phenol-biphenyl-type phenolic resin provided by this invention allows for the recycling of catalysts, washing solutions, and removed phenol during the production process, making it a clean method for producing phenolic resin. Attached Figure Description

[0028] Figure 1 Infrared spectra of the phenol-biphenyl-type phenolic resins prepared in Example 1 and Comparative Example 1.

[0029] Figure 2 The phenol-biphenyl-type phenolic resins prepared in Example 1 and Comparative Example 1 13 C NMR spectrum.

[0030] Figure 3 A graph showing the reaction process using oxalic acid as a catalyst. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0032] In the following specific embodiments:

[0033] Viscosity testing: Cone-plate (ICI) high-temperature viscometer, RESEACH EQUIPMENT (LONDON) LTD.

[0034] Test conditions: temperature 150℃; cone size: 3 (measurement range 0 to 2.00 Pa·s); sample amount: 0.15±0.01 g.

[0035] Softening point test: FP900 thermal analyzer, Mettler, UK.

[0036] Example 1

[0037] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)biphenyl, 893 g (9.5 mol) of phenol, and 30.1 g of an acidic solution of zinc p-toluenesulfonate (pH = 2.0) were added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was heated and stirred, and the temperature was slowly increased to 90 °C for 3 h. After the reaction was completed, 1500 mL of L4-methyl-2-pentanone and 300 mL of deionized water were added and stirred for 20 min. After standing and separating into layers, the solvent phase was collected and washed with hot water until neutral. The solvent was then recovered by vacuum distillation and dried to obtain crude resin. Then, 3000 g of toluene was used for elution, followed by filtration, and the solvent was recovered by vacuum distillation. The solid phase was then dried under vacuum to obtain the product. The softening point was 108 °C; the hydroxyl equivalent was 200.62 g / eq; and the ortho-hydroxyl content was 74.63%.

[0038] The corresponding epoxy resin is prepared using the conventional epichlorohydrin / sodium hydroxide method. Using the phenol-biphenyl phenolate resin and epichlorohydrin produced in this invention as raw materials, with a molar ratio of phenol-biphenyl phenolate resin:epoxychlorohydrin:sodium hydroxide of 1:10:1, and sodium hydroxide as a catalyst, the reaction is carried out at 60°C for 4 hours to obtain a crude phenol-biphenyl type epoxy resin. This resin is then refined, washed, and desolventized to obtain the finished epoxy resin.

[0039] The corresponding epoxy resin softening point is 40.5℃; epoxy equivalent is 265.99 g / eq; melt viscosity is 37 mPa·s.

[0040] / 150℃.

[0041] Example 2

[0042] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)biphenyl, 893 g (9.5 mol) of phenol, and an acidic solution (pH = 2.0) of 25.45 g of magnesium methanesulfonate were added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was heated and stirred, and the temperature was slowly increased to 90 °C for 3 h. After the reaction was complete, 1500 ml of 4-methyl-2-pentanone and 300 ml of deionized water were added and stirred for 20 min. After standing and separating the layers, the solvent phase was collected and washed with hot water until neutral. The solvent was then recovered by vacuum distillation, and the product was dried to obtain the crude product. The crude product was then eluted with 3000 g of toluene, filtered, and the solvent was recovered by vacuum distillation. The solid phase was then dried under vacuum to obtain the final product. The softening point was 105 °C; the hydroxyl equivalent was 210.19 g / eq; and the ortho-isotope ratio was 70.92%.

[0043] The corresponding epoxy resin was prepared using the conventional epichlorohydrin / sodium hydroxide method, and the specific preparation process is as described in Example 1.

[0044] The corresponding epoxy resin softening point is 56.1℃; epoxy equivalent is 290.8 g / eq; melt viscosity is 90 mPa·s / 150℃.

[0045] Comparative Example 1

[0046] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)biphenyl, 893 g (9.5 mol) of phenol, and 7.1 g of an acidic solution of zinc p-toluenesulfonate (pH = 4.0) were added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was heated and stirred, and the temperature was slowly increased to 100 °C for 12 h. After the reaction was completed, 1500 ml of 4-methyl-2-pentanone and 300 ml of deionized water were added and stirred for 20 min. After standing and separating into layers, the solvent phase was collected and washed with hot water until neutral. The solvent was then recovered by vacuum distillation, and the product was dried to obtain the crude product. Then, 3000 g of toluene was used for elution, followed by filtration, and the solvent was recovered by vacuum distillation. The solid phase was then dried under vacuum to obtain the product. The softening point was 93 °C; the hydroxyl equivalent was 205.1 g / eq; and the ortho-hydroxyl content was 55.56%.

[0047] The corresponding epoxy resin was prepared using the conventional epichlorohydrin / sodium hydroxide method, and the specific preparation process is as described in Example 1.

[0048] The corresponding epoxy resin softening point is 58.9℃; epoxy equivalent is 282.70-290.8 g / eq; melt viscosity is 108 mPa·s / 150℃.

[0049] Comparative Example 2 (using p-toluenesulfonic acid as a catalyst)

[0050] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)biphenyl, 890 g (9.5 mol) and 893 g (9.5 mol) of phenol, and 4.5 g of p-toluenesulfonic acid (pH = 2.0) were added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was heated and stirred, and the temperature was slowly increased to 90 °C for 3 h. After the reaction was completed, 1500 ml of 4-methyl-2-pentanone and 300 ml of deionized water were added and stirred for 20 min. After standing and separating into layers, the solvent phase was collected and washed with hot water until neutral. The solvent was then recovered by vacuum distillation, and dried to obtain an orange-yellow transparent solid. The solid was then eluted with 3000 g of ethyl acetate, filtered, and the solvent was recovered by vacuum distillation. The solid phase was then dried under vacuum to obtain the product; softening point 68.6 °C, hydroxyl equivalent 210.7 g / eq, ortho-hydroxyl content = 58.14%.

[0051] The corresponding epoxy resin was prepared using the conventional epichlorohydrin / sodium hydroxide method, as described in Example 1. The softening point of the corresponding epoxy resin was 56.5℃; the epoxy equivalent was 283.3 g / eq; and the melt viscosity was 40 mPa·s / 150℃.

[0052] Comparative Example 3 (Non-divalent metal salt)

[0053] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)biphenyl, 893 g (9.5 mol) of phenol, and an acidic solution (pH = 2.0) of 21.3 g of sodium methanesulfonate were added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was heated and stirred, and the temperature was slowly increased to 90 °C for 3 h. After the reaction was completed, 1500 ml of 4-methyl-2-pentanone and 300 ml of deionized water were added and stirred for 20 min. After standing and separating into layers, the solvent phase was collected and washed with hot water until neutral. The solvent was then recovered by vacuum distillation and dried to obtain crude resin. Then, 3000 g of toluene was used for elution, followed by filtration, and the solvent was recovered by vacuum distillation. The solid phase was then dried under vacuum to obtain the product. The softening point was 80.4 °C; the hydroxyl equivalent was 202.7 g / eq; and the ortho-position ratio was 46.09%.

[0054] The corresponding epoxy resin was prepared using the conventional epichlorohydrin / sodium hydroxide method, and the specific preparation process is as described in Example 1.

[0055] The corresponding epoxy resin softening point is 61.0℃; epoxy equivalent is 273.8 g / eq; melt viscosity is 38.8 mPa·s / 150℃.

[0056] Comparative Example 4 (using a weak acid)

[0057] Under nitrogen protection, 605 g (2.5 mol) of 4',4-bis(methoxymethyl)phenol, 893 g (9.5 mol) of phenol, and 60.5 g of oxalic acid (pH = 2.0) were added to a 250 ml four-necked flask, and the mixture was stirred while the temperature was slowly increased to 130 °C to carry out the reaction. The reaction did not yield a product because the starting material did not disappear within a long time.

[0058] The infrared spectra of the phenol-biphenyl-type phenolic resins prepared in Example 1 and Comparative Example 2 are shown in [reference]. Figure 1 :

[0059] like Figure 1 As shown, the raw material, biphenyl dimethyl ether, is at a temperature of 3000–2770 cm⁻¹. -1 There are strong stretching vibration absorption peaks of alkyl hydrocarbons (-CH3 and -CH2-). In the examples and comparative examples, these absorption peaks are significantly smaller, and only weak absorption of -CH2- is present, indicating that the methoxy reaction is basically complete.

[0060] 1270~1010cm -1 The area near the peak is a characteristic absorption peak for ether bonds (-COC-), with the starting material at 1120 cm⁻¹. -1 The single peak at the point of reaction became a broad peak after the reaction. (The product contains phenolic hydroxyl groups, and the stretching vibration peak of the carbon-oxygen bond of the phenolic hydroxyl group is close to the characteristic peak of the ether bond.)

[0061] 3350cm -1 The absorption peak of the phenolic hydroxyl stretching vibration is located near the 3519 cm⁻¹. In Example 1, due to the narrow molecular weight distribution of the product, the absorption of the phenolic hydroxyl vibration is relatively uniform, thus the peak is at 3519 cm⁻¹. -1 A relatively sharp peak appears at 3350cm; the comparative product shows this peak. -1 A large blunt peak appears nearby, which is due to the wide molecular weight distribution of the product and the difference in the environment of the phenolic hydroxyl group, resulting in a wider absorption peak.

[0062] 803cm -1 and 752cm -1 The absorption peaks at these two locations represent the characteristic absorptions of the para-substituted and ortho-substituted methylene groups on the benzene ring, respectively. The characteristic absorptions at these two locations also show some differences between Example 1 and Comparative Example 1. In Example 1, the peak at 752 cm⁻¹ is higher. -1 The characteristic absorption at this location is significantly stronger than that of the comparative sample.

[0063] The phenol-biphenylene-type phenolic resins prepared in Example 1 and Comparative Example 2 13 The C NMR spectrum is as follows Figure 2 As shown:

[0064] like Figure 2 As shown, from 13Analysis of the C-NMR spectrum shows that the 13C-NMR of the raw material is a BMB methyl carbon atom signal peak (-CH3) at 58.12 ppm and a BMB methylene carbon atom signal peak (-CH2-) at 74.16 ppm. However, these two peaks have disappeared in the product, indicating that the reaction occurred at the methoxy functional group and the reaction was complete.

[0065] Of particular interest is the 35–42 ppm region, which contains the signal peaks of carbon atoms in the methylene bridge (RAr-CH2-ArR) connecting the benzene ring. The 35.5–36 ppm region represents ortho-ortho (OO) connections, and the 41–41.5 ppm region represents para-para (pp) connections. In the spectrum of Example 1, the para-para peak at 41 ppm is weak, while the ortho peak signal is relatively strong, indicating that the methylene groups in the resin molecular chain are mainly connected in an ortho manner, suggesting a high ortho-position product. In contrast, the absorption signal at 41 ppm in Comparative Example 1 is much stronger, almost matching the intensity of the para absorption peak.

[0066] Figure 3 This is a comparison chart showing the reaction process using oxalic acid as a catalyst in Example 4.

Claims

1. A method for preparing a high-ortho-phenol-biphenol-formaldehyde resin, characterized in that: Phenol and 4,4'-biphenyl dimethyl ether are subjected to a polycondensation reaction in the presence of a catalyst. The product obtained from the polycondensation reaction is washed with water and extracted. The high-ortho-phenol-biphenylene aldehyde resin is recovered from the extracted organic phase, and the raffinate is an aqueous phase containing the catalyst. The catalyst is an acidic solution containing a divalent metal sulfonate.

2. The method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1, characterized in that: The catalyst has a pH ≤ 2; The divalent metal sulfonate is a transition metal ion or a magnesium ion, and the sulfonate is p-toluenesulfonate or methanesulfonate.

3. The method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1 or 2, characterized in that: The amount of catalyst used is 1 to 10% of the mass of phenol.

4. The method for preparing a high-ortho-phenol-biphenol aldehyde resin according to claim 3, characterized in that: The amount of catalyst used is 3 to 5% of the mass of phenol.

5. The method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1, characterized in that: The molar ratio of phenol to 4,4'-biphenyl dimethyl ether is 2 to 20:

1.

6. The method for preparing a high-ortho-phenol-biphenol aldehyde resin according to claim 5, characterized in that: The molar ratio of phenol to 4,4'-biphenyl dimethyl ether is 2 to 10:

1.

7. A method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1, 2, 4, 5 or 6, characterized in that: The conditions for the polycondensation reaction are: temperature 40–150°C and time 0.5–48 h.

8. The method for preparing a high-ortho-phenol-biphenol aldehyde resin according to claim 7, characterized in that: The conditions for the polycondensation reaction are: temperature 70–100℃ and time 1–4h.

9. The method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1, characterized in that: The extraction process uses at least one of butanone, methyl isobutyl ketone, and toluene as the extractant.

10. The method for preparing a high-ortho-phenol-biphenol-formaldehyde resin according to claim 1, characterized in that: The process of recovering ortho-phenol-biphenyl phenol-formaldehyde resin from the extracted organic phase is as follows: the extracted organic phase is washed with water and the extractant and phenol are recovered by vacuum distillation, and then separated by elution to obtain high ortho-phenol-biphenyl phenol-formaldehyde resin.

11. A high-ortho-phenol-biphenol-formaldehyde resin, characterized in that: It is obtained by the preparation method described in any one of claims 1 to 10.

12. The high-ortho-phenol-biphenol-formaldehyde resin according to claim 11, characterized in that: The ortho-substituted rate of the high ortho-phenol-biphenol resin is not less than 70%.

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