Alumina-modified phenolic resin-based copper-clad plate and preparation method thereof

Abstract

The invention relates to the technical field of copper-clad plates, in particular to a phenolic resin-based copper-clad plate modified by aluminum oxide and a preparation method thereof.The preparation method comprises the following processes that 3, 9-dichloro-2, 4, 8, 10-tetraoxa-3, 9-diphosphospiro [5.5] undecane 3, 9-dioxide reacts with benzenediol and acetonitrile, triethylamine is added after the temperature is increased, and a spiro derivative is obtained; the preparation method comprises the following steps: mixing 1, 1-bis (ethyoxyl) silyl cyclobutane, 1-amino-2-(dimethyl ethyoxyl silyl) propane, deionized water and tetrahydrofuran to obtain amino polycarbosilane; the preparation method comprises the following steps: adding amino polycarbosilane and a spiro derivative into absolute ethyl alcohol to obtain a phenol-containing compound; a Si-O-Si structure with good heat resistance and a spirocyclic phosphate structure with good thermal stability are keyed into a phenol-containing compound, so that the purpose of improving the flame retardant property of the copper-clad plate is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of copper clad laminates, in particular to a phenolic resin-based copper clad laminate modified with aluminum oxide and a preparation method thereof. Background Art

[0002] Copper-clad laminate (CCL) is a sheet material made by impregnating electronic fiberglass cloth or other reinforcing materials with resin, coating one or both sides with copper foil, and then hot-pressing. It primarily serves as interconnect, insulation, and support for printed circuit boards. It significantly influences signal transmission speed, energy loss, and characteristic impedance within the circuit, making it a crucial foundational material for printed circuit boards.

[0003] Phenolic resin is a general term for resinous polymers formed by the polycondensation of phenol and aldehyde in the presence of acidic or alkaline catalysts. It exhibits excellent adhesion, heat resistance, high carbonization rate at high temperatures, and corrosion resistance, making it a commonly used binder for refractory materials.

[0004] When phenolic resin is used in copper clad laminates, the flame retardancy of phenolic resin-based materials needs to be further improved to ensure the flame retardancy of the copper clad laminates. Therefore, we propose a phenolic resin-based copper clad laminate modified with aluminum oxide and a preparation method thereof. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A method for preparing a phenolic resin-based copper clad laminate modified with alumina comprises the following steps: mixing a phenolic compound, modified alumina, an alkaline catalyst, phenol, and formaldehyde, reacting the mixture at 95-105°C for 4-5 hours, shearing the mixture, and decompressing and dehydrating the mixture to obtain a modified phenolic resin-based impregnating material;

[0008] Put the glass fiber cloth into the modified phenolic resin impregnation material, soak it for 20 to 30 minutes, take it out, and bake it at 160 to 170°C for 4 to 6 minutes to obtain a prepreg;

[0009] Hot pressing and curing copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide;

[0010] The phenol-containing compound comprises the following components: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, 1,1-bis(ethoxy)silylcyclobutane, and 1-amino-2-(dimethylethoxysilyl)propane.

[0011] Furthermore, the alkaline catalyst is one or a mixture of ammonia water, sodium carbonate, magnesium carbonate, and alkaline earth metal oxides.

[0012] Furthermore, shearing is performed at high speed through the pipeline, with a shear rate of 4150 to 4250 r / min.

[0013] Furthermore, the weight ratio of the glass fiber cloth to the modified phenolic resin impregnation material is 1:(6-8).

[0014] Furthermore, the process conditions of hot pressing are: temperature 220-240° C., pressure 2.5-3.0 MPa, and time 1-1.5 h.

[0015] Furthermore, the modified phenolic resin-based impregnating material includes the following components by mass: 78 to 86 parts of phenol, 22 to 24 parts of formaldehyde, 8 to 16 parts of a phenol-containing compound, 10 to 20 parts of modified alumina and 10 to 11 parts of an alkaline catalyst.

[0016] In the above technical solution, when a phenolic resin with a nitrogen-silicon-phosphorus helical structure is prepared by combining 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, 1,1-bis(ethoxy)silylcyclobutane, and 1-amino-2-(dimethylethoxysilyl)propane, the flame retardancy of the bis(phenoxy)pentaerythritol bisphosphite with the helical structure is significantly higher than that of the unmodified phenolic resin; when a nitrogen-containing silicone resin is used, the heat resistance of the prepared modified phenolic resin is significantly improved; mainly, a Si—O—Si structure with good heat resistance and a spirocyclic phosphate structure with good thermal stability are typed into the phenolic resin structure, and phosphorus and silicon elements are introduced into the phenolic resin in the form of a spirocyclic phosphate structure and a Si—O—Si structure, respectively, which can effectively improve the heat resistance of the phenolic resin, thereby enhancing the flame retardant properties of the phenolic resin, thereby achieving enhanced flame retardant properties of the copper clad laminate.

[0017] Further, the phenol-containing compound is prepared by the following process:

[0018] Step A, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, and acetonitrile are mixed and stirred for 20 to 40 minutes, and triethylamine is added dropwise after heating to 75 to 85° C., and the reaction is carried out at 70 to 90° C. for 5 to 7 hours; cooling and filtering to obtain a white precipitate, washing with acetonitrile and deionized water in sequence, and drying at 95 to 105° C. to constant weight to obtain a spiro derivative;

[0019] Step B, 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran were mixed, mechanically stirred, and kept warm at 60-70° C. for 2-4 hours, filtered, and then distilled to obtain aminopolycarbosilane;

[0020] Step C: adding aminopolycarbosilane and spiro derivative into anhydrous ethanol, mechanically stirring, keeping the temperature at 40-60° C. for reaction for 2-4 hours, filtering and distilling to obtain a phenol-containing compound.

[0021] Furthermore, in step A, the molar ratio of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and diphenol is 1:(1.0-1.1);

[0022] The weight ratio of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and acetonitrile is (18-19):1; the amount of triethylamine used is 67-68% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide.

[0023] Furthermore, in step B, the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:(1.0-1.1); the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is (10-11):1; and the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is (10-11):(1-1.5).

[0024] Furthermore, in step C, the mass ratio of aminopolycarbosilane to spiro derivative is 7:(9-11), and the weight ratio of the total weight of aminopolycarbosilane and spiro derivative to anhydrous ethanol is 1:(6-10).

[0025] In the above technical solution, a spiro derivative containing a phenol structure is generated by reacting 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide with hydroquinone, introducing a spiro structure into phenol, thereby achieving the technical effect of increasing the stability of the phenolic resin. Compared with ordinary phenol, the phenolic compound containing phosphorus silicon and a spiro structure obtained by reacting aminopolycarbosilane with the spiro derivative exhibits stronger stability and heat resistance. The phenolic compound is modified by aminopolycarbosilane to contain primary amine groups. During the preparation of the phenolic resin, the phenolic compound can react with formaldehyde and phenol groups to form a benzoxazine structure, which can effectively improve its heat resistance and contribute to the improvement of the flame retardant and mechanical properties of the phenolic resin.

[0026] Furthermore, the aluminum oxide is surface modified, and the specific process is as follows:

[0027] Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 3-4, let it stand for hydrolysis for 1-2 hours, add alumina, heat in a water bath, and mechanically stir for 5-6 hours; pour off the supernatant, add anhydrous ethanol, ultrasonically wash and filter to obtain modified alumina.

[0028] Furthermore, the volume ratio of alumina to 95% ethanol is 1:(3-5), the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:(19-21), the concentration of citric acid aqueous solution is 10%, the water bath heating temperature is 40-50°C, the mechanical stirring speed is 400-500 r / min, the ultrasonic washing frequency is 1.6-1.8 MHz, and the ultrasonic power is 400-500 W.

[0029] In the above technical solution, the surface modification of aluminum oxide is achieved by adding a coupling agent, so that the aluminum oxide has good dispersion uniformity and thermal conductivity, thereby enhancing the thermal conductivity of the copper clad laminate.

[0030] Furthermore, in step B, the mechanical stirring speed is 300-500 r / min.

[0031] Furthermore, in step C, the mechanical stirring speed is 300-500 r / min.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention describes a method for preparing a phenolic resin-based copper-clad laminate modified with aluminum oxide. When preparing a phenolic resin containing a nitrogen-silicon-phosphorus helical structure by combining 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, 1,1-bis(ethoxy)silylcyclobutane, and aminosilane, the flame retardancy of the bis(phenoxy)pentaerythritol bisphosphite with the helical structure is significantly higher than that of the unmodified phenolic resin.

[0034] 2. The present invention describes a method for preparing a phenolic resin-based copper-clad laminate modified with aluminum oxide. When a nitrogen-containing silicone resin is used, the heat resistance of the prepared modified phenolic resin is significantly improved. The method mainly involves introducing a Si-O-Si structure with good heat resistance and a spirophosphate structure with good thermal stability into the phenolic resin structure. The phosphorus element and the silicon element are introduced into the phenolic resin in the form of a spirophosphate structure and a Si-O-Si structure, respectively, which can effectively improve the heat resistance of the phenolic resin and thereby enhance the flame retardant properties of the phenolic resin.

[0035] 3. The present invention describes a method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide. A coupling agent is used to modify the surface of aluminum oxide to achieve a modification of the aluminum oxide. The modified aluminum oxide is added to the phenolic resin, which can effectively improve the thermal conductivity of the phenolic resin-based material, thereby enhancing the flame retardant properties of the phenolic resin, thereby enhancing the flame retardant properties of the copper clad laminate. DETAILED DESCRIPTION

[0036] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0037] In the following specific embodiments, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide: from Shanghai Shangyinsi Biochemical Pharmaceutical Co., Ltd.; hydroquinone: from Zhengzhou Shengyu Chemical Co., Ltd.; acetonitrile: from Shanghai Yaokan Chemical Co., Ltd.; 1,1-bis(ethoxy)silylcyclobutane (CAS: 74861-46-4): from Hubei Jiutian Biopharmaceutical Technology Co., Ltd.; 1-amino-2-(dimethylethoxysilyl)propane (CAS: 1012859-70-9): from Shandong Runfu Calcium Magnesium Chemical Technology Co., Ltd.; Tetrahydrofuran: sourced from Hangzhou Dingyan Chemical Co., Ltd.; KH-560 silane coupling agent: sourced from Dongguan Shanyi Plastics Co., Ltd.; Alumina: brand AO-G, particle size 500-2000nm, sourced from Shanghai MCC New Materials Co., Ltd.; Formaldehyde: sourced from Jinan Century Tongda Chemical Co., Ltd.; Glass fiber cloth: specification 2116, thickness 0.08mm, sourced from Keli New Materials Co., Ltd.; Copper foil: 0.5 ounces electrolytic copper foil, sourced from Shenzhen Jintongdu Metal Materials Co., Ltd.; Alkaline catalyst is magnesium carbonate: sourced from Shanghai Myrrel Biochemical Technology Co., Ltd.

[0038] Example 1: A method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide, comprising the following steps:

[0039] Step 1: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide was mixed with benzene and acetonitrile and stirred for 20 minutes. After heating to 75°C, triethylamine was added dropwise and the mixture was kept at 70°C for 5 hours. The white precipitate was cooled and filtered to obtain the white precipitate. The precipitate was washed with acetonitrile and deionized water in turn and dried at 95°C to constant weight to obtain the spiro derivative. The molar ratio of 0-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to hydroquinone is 1:1.0; the weight ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is 18:1; the amount of triethylamine used is 67% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide;

[0040] Step 2: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran are mixed, mechanically stirred, and kept warm at 60° C. for 2 hours. After filtering, the mixture is distilled to obtain aminopolycarbosilane; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:1.0; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is 10:1; and the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is 10:1;

[0041] Step 3: adding the aminopolycarbosilane and the spiro derivative to anhydrous ethanol, mechanically stirring, and reacting at 40° C. for 2 hours, filtering, and distilling to obtain a phenol-containing compound; the mass ratio of the aminopolycarbosilane to the spiro derivative is 7:9, and the weight ratio of the total weight of the aminopolycarbosilane and the spiro derivative to the anhydrous ethanol is 1:6;

[0042] Step 4: Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 3, let it stand for hydrolysis for 1 hour, add alumina, heat it in a water bath to 40°C, and stir it mechanically for 5 hours; pour out the supernatant, add anhydrous ethanol, ultrasonically wash it, and then filter it to obtain modified alumina; the volume ratio of alumina to 95% ethanol is 1:3, and the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:19;

[0043] Step 5: mixing a phenol-containing compound, modified alumina, an alkaline catalyst, formaldehyde, and phenol, and carrying out a heat-insulating reaction at 95° C. for 4 hours, followed by shearing and decompression dehydration to obtain a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material comprises the following components by weight: 86 parts of phenol, 24 parts of formaldehyde, 8 parts of a phenol-containing compound, 10 parts of modified alumina, and 10 parts of an alkaline catalyst;

[0044] Step 6: Place the fiberglass cloth in the modified phenolic resin impregnation material, impregnate for 20 minutes, take out the fiberglass cloth and bake it at 160°C for 4 minutes to obtain a prepreg. The weight ratio of the fiberglass cloth to the modified phenolic resin impregnation material is 1:6.

[0045] Step 7: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 220° C., pressure 2.5 MPa, and time 1 hour.

[0046] Example 2: A method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide, comprising the following steps:

[0047] Step 1: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, benzene diphenol and acetonitrile were mixed and stirred for 30 minutes, and triethylamine was added dropwise after heating to 80°C. The mixture was kept warm at 80°C for 6 hours. A white precipitate was obtained by cooling and filtering, and the precipitate was washed with acetonitrile and deionized water in turn. The spiro derivative was obtained by drying at 100°C to constant weight. The molar ratio of oxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to hydroquinone is 1:1.05; the weight ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is 18.5:1; the amount of triethylamine used is 67.5% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide;

[0048] Step 2: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran are mixed, mechanically stirred, and kept warm at 65° C. for 3 hours. After filtration, the mixture is distilled to obtain aminopolycarbosilane; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:1.05; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is 10.5:1; and the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is 10:1.5;

[0049] Step 3: adding the aminopolycarbosilane and the spiro derivative to anhydrous ethanol, mechanically stirring, and reacting at 50° C. for 3 hours, filtering, and distilling to obtain a phenol-containing compound; the mass ratio of the aminopolycarbosilane to the spiro derivative is 7:10, and the weight ratio of the total weight of the aminopolycarbosilane and the spiro derivative to the anhydrous ethanol is 1:8;

[0050] Step 4: Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 3, let it stand for hydrolysis for 1.5 hours, add alumina, heat it in a water bath to 45°C, and stir it mechanically for 5.5 hours; pour off the supernatant, add anhydrous ethanol, ultrasonically wash it, and then filter it to obtain modified alumina; the volume ratio of alumina to 95% ethanol is 1:4, and the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:20;

[0051] Step 5: mixing the phenol-containing compound, modified alumina, alkaline catalyst, formaldehyde, and phenol, carrying out a heat-insulating reaction at 100° C. for 4.5 hours, shearing, and decompressing to obtain a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material comprises the following components by weight: 82 parts of phenol, 23 parts of formaldehyde, 12 parts of the phenol-containing compound, 15 parts of the modified alumina, and 10.5 parts of the alkaline catalyst;

[0052] Step 6: Place the glass fiber cloth in the modified phenolic resin impregnation material, impregnate for 25 minutes, take out the glass fiber cloth and bake it at 165°C for 5 minutes to obtain a prepreg. The weight ratio of the glass fiber cloth to the modified phenolic resin impregnation material is 1:7;

[0053] Step 7: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 230° C., pressure 2.75 MPa, and time 1.25 h.

[0054] Example 3: A method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide, comprising the following steps:

[0055] Step 1: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide was mixed with benzene and acetonitrile and stirred for 40 min. After heating to 85°C, triethylamine was added dropwise and the mixture was kept at 85°C for 7 h. The white precipitate was cooled and filtered to obtain the white precipitate. The precipitate was washed with acetonitrile and deionized water in turn and dried at 105°C to constant weight to obtain the spiro derivative, 3,9-dichloro-2,4,8,1 The molar ratio of 0-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to hydroquinone is 1:1.1; the weight ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is 19:1; the amount of triethylamine used is 68% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide;

[0056] Step 2: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran are mixed, mechanically stirred, and kept warm at 70°C for 4 hours. After filtering, the mixture is distilled to obtain aminopolycarbosilane; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:1.1; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is 11:1; and the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is 11:1;

[0057] Step 3: adding the aminopolycarbosilane and the spiro derivative to anhydrous ethanol, mechanically stirring, and reacting at 60° C. for 4 hours, filtering, and distilling to obtain a phenol-containing compound; the mass ratio of the aminopolycarbosilane to the spiro derivative is 7:11, and the weight ratio of the total weight of the aminopolycarbosilane and the spiro derivative to the anhydrous ethanol is 1:10;

[0058] Step 4: Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 4, let it stand for hydrolysis for 2 hours, add alumina, heat in a water bath, and mechanically stir for 6 hours; pour off the supernatant, add anhydrous ethanol, ultrasonically wash, and filter to obtain modified alumina; the volume ratio of alumina to 95% ethanol is 1:5, and the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:21;

[0059] Step 5: mixing a phenol-containing compound, modified alumina, an alkaline catalyst, formaldehyde, and phenol, carrying out a heat-insulating reaction at 105° C. for 5 hours, shearing, and dehydrating under reduced pressure to prepare a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material includes the following components by weight: 78 parts of phenol, 22 parts of formaldehyde, 16 parts of a phenol-containing compound, 20 parts of modified alumina, and 11 parts of an alkaline catalyst;

[0060] Step 6: Place the fiberglass cloth in the modified phenolic resin impregnation material and impregnate for 30 minutes. Then take out the fiberglass cloth and bake it at 170°C for 6 minutes to obtain a prepreg. The weight ratio of the fiberglass cloth to the modified phenolic resin impregnation material is 1:8.

[0061] Step 7: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 240° C., pressure 3.0 MPa, and time 1.5 hours.

[0062] Comparative Example 1: The difference from Example 1 is that aminopolycarbosilane was not prepared in this comparative example;

[0063] Step 1: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide was mixed with benzene and acetonitrile and stirred for 20 min. After heating to 75°C, triethylamine was added dropwise and the mixture was kept at 70°C for 5 h. The white precipitate was cooled and filtered to obtain the white precipitate. The precipitate was washed with acetonitrile and deionized water in turn and dried at 95°C to constant weight to obtain the spiro derivative, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide. The molar ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to hydroquinone is 1:1.0, the weight ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is 18:1, and the amount of triethylamine used is 67% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide;

[0064] Step 2: adding 1-amino-2-(dimethylethoxysilyl)propane and the spiro derivative to anhydrous ethanol, mechanically stirring, and reacting at 40° C. for 2 hours. Filtering and distilling to obtain a phenol-containing compound; the mass ratio of 1-amino-2-(dimethylethoxysilyl)propane to the spiro derivative is 3:9, and the weight ratio of the total weight of 1-amino-2-(dimethylethoxysilyl)propane and the spiro derivative to anhydrous ethanol is 1:6;

[0065] Step 3: Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 3, let it stand for hydrolysis for 1 hour, add alumina, heat it in a water bath to 40°C, and stir it mechanically for 5 hours; pour out the supernatant, add anhydrous ethanol, ultrasonically wash it, and then filter it to obtain modified alumina; the volume ratio of alumina to 95% ethanol is 1:3, and the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:19;

[0066] Step 3: mixing a phenol-containing compound, modified alumina, an alkaline catalyst, formaldehyde, and phenol, and carrying out a heat-insulating reaction at 95° C. for 4 hours, followed by shearing and decompression dehydration to obtain a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material comprises the following components by weight: 86 parts of phenol, 24 parts of formaldehyde, 8 parts of a phenol-containing compound, 10 parts of modified alumina, and 10 parts of an alkaline catalyst;

[0067] Step 4: Place the fiberglass cloth in the modified phenolic resin impregnation material and impregnate for 20 minutes. Then take out the fiberglass cloth and bake it at 160°C for 4 minutes to obtain a prepreg. The weight ratio of the fiberglass cloth to the modified phenolic resin impregnation material is 1:6.

[0068] Step 5: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 220° C., pressure 2.5 MPa, and time 1 hour.

[0069] Comparative Example 2: The difference from Example 2 is that the aluminum oxide in this comparative example is unmodified;

[0070] Step 1: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, benzene diol and acetonitrile were mixed and stirred for 30 minutes, and triethylamine was added dropwise after heating to 80°C. The mixture was kept warm at 80°C for 6 hours. A white precipitate was obtained by cooling and filtration, and the precipitate was washed with acetonitrile and deionized water in turn. The spiro derivative was obtained by drying at 100°C to constant weight. The molar ratio of oxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to hydroquinone is 1:1.05, and the weight ratio of 9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is 18.5:1; the amount of triethylamine used is 67.5% of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide;

[0071] Step 2: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran are mixed, mechanically stirred, and kept warm at 65°C for 3 hours. After filtration, the mixture is distilled to obtain aminopolycarbosilane; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:1.05; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is 10.5:1; and the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is 10:1.5;

[0072] Step 3: adding the aminopolycarbosilane and the spiro derivative to anhydrous ethanol, mechanically stirring, and reacting at 50° C. for 3 hours, filtering, and distilling to obtain a phenol-containing compound; the mass ratio of the aminopolycarbosilane to the spiro derivative is 7:9, and the weight ratio of the total weight of the aminopolycarbosilane and the spiro derivative to the anhydrous ethanol is 1:6;

[0073] Step 4: mixing a phenol-containing compound, aluminum oxide, an alkaline catalyst, formaldehyde, and phenol, and carrying out a heat-insulating reaction at 100° C. for 4.5 hours, followed by shearing and decompression dehydration to obtain a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material comprises the following components by mass: 86 parts of phenol, 24 parts of formaldehyde, 8 parts of a phenol-containing compound, 10 parts of modified aluminum oxide, and 10 parts of an alkaline catalyst;

[0074] Step 5: Place the glass fiber cloth in the modified phenolic resin impregnation material and impregnate for 25 minutes. Then, take out the glass fiber cloth and bake it at 165°C for 5 minutes to obtain a prepreg. The weight ratio of the glass fiber cloth to the modified phenolic resin impregnation material is 1:7.

[0075] Step 6: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 230° C., pressure 2.75 MPa, and time 1.25 h.

[0076] Comparative Example 3: The difference from Example 2 is that no spiro derivative was prepared in this comparative example;

[0077] Step 1: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran are mixed, mechanically stirred, kept warm at 65°C for 3 hours, filtered, and then distilled to obtain aminopolycarbosilane; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and 1-amino-2-(dimethylethoxysilyl)propane is 1:1.05; the molar ratio of 1,1-bis(ethoxy)silylcyclobutane and deionized water is 10.5:1; the volume ratio of 1,1-bis(ethoxy)silylcyclobutane and tetrahydrofuran is 10:1.5;

[0078] Step 2: Add KH-560 silane coupling agent to 95% ethanol, add citric acid aqueous solution to adjust the pH to 3, let it stand for hydrolysis for 1.5 hours, add alumina, heat it in a water bath to 45°C, and stir it mechanically for 5.5 hours; pour off the supernatant, add anhydrous ethanol, ultrasonically wash it, and then filter it to obtain modified alumina; the volume ratio of alumina to 95% ethanol is 1:4, and the volume ratio of KH-560 silane coupling agent to 95% ethanol is 1:20;

[0079] Step 3: Phenol, modified alumina, alkaline catalyst, formaldehyde, and aminopolycarbosilane are mixed and reacted at 100° C. for 4.5 hours, followed by shearing and decompression dehydration to obtain a modified phenolic resin-based impregnation material; the modified phenolic resin-based impregnation material comprises the following components by weight: 86 parts of phenol, 24 parts of formaldehyde, 8 parts of aminopolycarbosilane, 10 parts of modified alumina, and 10 parts of alkaline catalyst;

[0080] Step 4: Place the fiberglass cloth in the modified phenolic resin impregnation material and impregnate for 25 minutes. Then, take out the fiberglass cloth and bake it at 165°C for 5 minutes to obtain a prepreg. The weight ratio of the fiberglass cloth to the modified phenolic resin impregnation material is 1:7.

[0081] Step 5: Hot-press and solidify the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 230° C., pressure 2.75 MPa, and time 1.25 h.

[0082] Comparative Example 4: A method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide, comprising the following steps:

[0083] Phenol, aluminum oxide, an alkaline catalyst, and formaldehyde are mixed and reacted at 100°C for 4.5 hours, then sheared and dehydrated under reduced pressure to obtain a phenolic resin-based impregnating material; glass fiber cloth is then placed in the phenolic resin impregnating material and impregnated for 25 minutes, and then taken out and baked at 165°C for 5 minutes to obtain a semi-cured sheet, wherein the weight ratio of glass fiber cloth to phenolic resin impregnating material is 1:7; copper foil is hot-pressed and cured on both sides of the semi-cured sheet to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide, wherein the hot-pressing conditions are: temperature 230°C, pressure 2.75 MPa, and time 1.25 hours; the phenolic resin impregnating material includes the following components by mass: 94 parts of phenol, 24 parts of formaldehyde, 10 parts of aluminum oxide, and 10 parts of an alkaline catalyst.

[0084] Experiment: The phenolic resin-based copper-clad laminates modified with aluminum oxide obtained in Examples 1-3 and Comparative Examples 1-4 were used to prepare samples, and their properties were tested and the test results were recorded:

[0085] Test reference standard method description:

[0086] (1) Limiting oxygen index: According to the GB / T 2406.2-2009 standard and test method, an oxygen index analyzer was used to cure the phenolic resin impregnation material to prepare a specimen with a size of 130 mm × 7 mm × 3 mm;

[0087] (2) Flame retardant grade: According to the UL-94 standard and test method, the phenolic resin impregnation material was cured to prepare a specimen with a specimen size of 125 mm × 13 mm × 0.7 mm;

[0088] (3) Thermal conductivity: ASTM D5470 standard and test method;

[0089] (4) Tensile shear strength: According to GB / T7124-2008, an electronic universal testing machine was used.

[0090] Test results:

[0091]

[0092]

[0093] According to the data in the above table, we can clearly draw the following conclusions:

[0094] The copper clad laminates obtained in Examples 1-3 were compared with those obtained in Comparative Examples 1-4. The test results show that:

[0095] 1. By comparing Examples 1-3, it can be seen that the phenolic resin-based copper clad laminate prepared under the conditions of Example 2 has better comprehensive performance;

[0096] 2. Compared with Examples 1-3, the limiting oxygen index, flame retardancy, thermal conductivity and tensile shear strength of the products obtained in Comparative Examples 1-4 are all reduced, indicating that the alumina-modified phenolic resin-based copper clad laminate prepared in the present invention has better flame retardancy and mechanical properties.

[0097] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a phenolic resin-based copper-clad laminate modified with aluminum oxide, characterized in that: The specific preparation steps are as follows: Step 1: mixing a phenolic compound, modified alumina, an alkaline catalyst, phenol, and formaldehyde, and carrying out a heat-insulating reaction for 4 to 5 hours, followed by shearing and decompression dehydration to obtain a modified phenolic resin-based impregnating material; Step 2: Place the fiberglass cloth in the modified phenolic resin impregnation material, impregnate for 20 to 30 minutes, take out the fiberglass cloth and bake it for 4 to 6 minutes to obtain a prepreg; Step 3: hot pressing and curing the copper foil on both sides of the prepreg to obtain a phenolic resin-based copper clad laminate modified with aluminum oxide; The phenol-containing compound comprises the following components: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, 1,1-bis(ethoxy)silylcyclobutane, and 1-amino-2-(dimethylethoxysilyl)propane.

2. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 1, wherein: The phenol-containing compound is prepared by the following process: Step A: 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, hydroquinone, and acetonitrile were mixed and stirred for 20 to 40 minutes, and triethylamine was added dropwise after heating to 75 to 85°C. The reaction was kept at 70 to 90°C for 5 to 7 hours. The white precipitate was cooled and filtered to obtain the precipitate, which was washed with acetonitrile and deionized water in sequence, and dried at 95 to 105°C to constant weight to obtain a spiro derivative. Step B: 1,1-bis(ethoxy)silylcyclobutane, 1-amino-2-(dimethylethoxysilyl)propane, deionized water, and tetrahydrofuran were mixed, mechanically stirred, and kept warm for 2 to 4 hours, filtered, and then distilled to obtain aminopolycarbosilane; Step C: adding aminopolycarbosilane and spiro derivative into anhydrous ethanol, mechanically stirring, keeping warm and reacting for 2 to 4 hours, filtering and distilling to obtain a phenol-containing compound.

3. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 1, wherein: In step one, the temperature of the heat preservation reaction is 95-105°C, and the shear rate is 4150-4250 r / min; in step two, the baking temperature is 160-170°C; in step three, hot pressing is performed at 220-240°C, the pressure is 2.5-3.0 MPa, and the hot pressing is performed for 1-1.5 hours.

4. The method for preparing a phenolic resin-based copper-clad laminate modified with aluminum oxide according to claim 2, wherein: In step A, the molar ratio of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to phenol is 1:(1.0-1.1); the weight ratio of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide to acetonitrile is (18-19):1; and the amount of triethylamine used is 67-68% of the amount of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide.

5. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 2, wherein: In step B, the molar ratio of 1,1-bis(ethoxy)silylcyclobutane to 1-amino-2-(dimethylethoxysilyl)propane is 1:(1.0-1.1); and in step C, the mass ratio of aminopolycarbosilane to spiro derivative is 7:(9-11).

6. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 1, wherein: The modified alumina is prepared by the following process: adding KH-560 silane coupling agent to 95% ethanol, adding citric acid aqueous solution to adjust the pH to 3-4, standing for hydrolysis for 1-2 hours, adding alumina, heating in a water bath, and mechanically stirring for 5-6 hours; pouring out the supernatant, adding anhydrous ethanol, ultrasonically washing, and then filtering to obtain the modified alumina.

7. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 1, wherein: The modified phenolic resin-based impregnating material comprises the following components by mass: 78 to 86 parts of phenol, 22 to 24 parts of formaldehyde, 8 to 16 parts of phenol-containing compounds, 10 to 20 parts of modified aluminum oxide and 10 to 11 parts of alkaline catalyst.

8. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 1, wherein: The alkaline catalyst is made from one or a mixture of ammonia water, sodium carbonate, magnesium carbonate, and alkaline earth metal oxides.

9. The method for preparing a phenolic resin-based copper clad laminate modified with aluminum oxide according to claim 8, wherein: The weight ratio of the glass fiber cloth to the modified phenolic resin impregnating material is 1:(6-8).

10. A phenolic resin-based copper-clad laminate modified with aluminum oxide, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 9.

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