Preparation method of low-dielectric halogen-free flame-retardant glass fiber prepreg

Abstract

The invention belongs to the technical field of electronic composite materials. The invention relates to a glass fiber prepreg, in particular to a preparation method of a low-dielectric halogen-free flame-retardant glass fiber prepreg. The preparation method comprises the following specific preparation steps: taking 20-25 parts by weight of a spherical inorganic flame retardant, 20-30 parts by weight of flaky polyether-ether-ketone and 60-80 parts by weight of fibrous polyether-ketone-ketone, mixing, and dispersing in 400-450 parts by weight of a dopamine solution to obtain an impregnation liquid; adjusting the pH value of the steeping liquor to alkalescence, and then steeping alkali-free glass fiber cloth into the steeping liquor to obtain a steeping material; and drying the impregnated material, heating, melting and cooling to obtain the low-dielectric halogen-free flame-retardant glass fiber prepreg. The sphericity degree of the spherical inorganic flame retardant is 0.85 to 0.90; the particle size distribution range of the spherical inorganic flame retardant is 10-120nm; the D50 of the flaky polyether-ether-ketone is 3 to 10 [mu] m; the length-diameter ratio of the fibrous polyetherketoneketone is 1: (40-50).

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic composite materials and more specifically relates to a method for preparing a low-dielectric halogen-free flame-retardant glass fiber prepreg. Background Art

[0002] Low-dielectric, halogen-free, flame-retardant glass fiber prepreg is a composite material made with glass fiber as the reinforcement, a low-dielectric resin as the matrix, and a halogen-free flame retardant. Its key features are its combination of low-dielectric properties and halogen-free flame retardancy, while avoiding the toxic gases produced by traditional halogen-based flame retardants during combustion.

[0003] Low-dielectric halogen-free flame-retardant glass fiber prepregs typically consist of a matrix resin, a flame retardant, and a reinforcing material. The matrix resin is typically epoxy resin, cyanate ester resin, or a modified version thereof. These resins offer excellent mechanical properties and thermal stability. Flame retardants primarily utilize phosphorus-nitrogen synergistic flame retardants, such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). These flame retardants do not release toxic gases during combustion and offer excellent flame retardancy. Glass fiber, the primary reinforcing material, offers high strength, high modulus, and excellent insulation properties. During preparation, glass fiber cloth is impregnated with a mixture containing the flame retardant and low-dielectric resin. The prepreg is then dried and cured to form the prepreg.

[0004] Low-dielectric halogen-free flame-retardant glass fiber prepregs must simultaneously meet the requirements of a low dielectric constant and excellent flame retardancy, but this presents a certain conflict. For example, while adding a large amount of flame retardant can improve flame retardancy, it can also lead to an increase in the dielectric constant and dielectric loss. Furthermore, the excessive use of flame retardants can increase the viscosity of the resin system, impacting its processability and mechanical properties. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that for glass fiber prepreg, it is necessary to simultaneously meet the requirements of low dielectric constant and good flame retardant performance. The present invention provides a method for preparing low dielectric halogen-free flame retardant glass fiber prepreg.

[0006] The purpose of the present invention is to provide a method for preparing a low-dielectric halogen-free flame-retardant glass fiber prepreg.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing a low-dielectric halogen-free flame-retardant glass fiber prepreg, the specific preparation steps comprising:

[0009] By weight, 20-25 parts of spherical inorganic flame retardant, 20-30 parts of flaky polyetheretherketone, and 60-80 parts of fibrous polyetherketoneketone are mixed and dispersed in 400-450 parts of dopamine solution to obtain an impregnation solution;

[0010] Adjusting the pH of the impregnation liquid to a weak alkaline state, and then impregnating the alkali-free glass fiber cloth in the impregnation liquid to obtain an impregnated material;

[0011] After the impregnated material is dried, heated and melted, and cooled, a low dielectric halogen-free flame-retardant glass fiber prepreg is obtained.

[0012] Beneficial effects of the above technical solution:

[0013] The above technical solution uses spherical inorganic flame retardant as the flame retardant component, so that the product achieves halogen-free flame retardant effect;

[0014] Furthermore, the spherical inorganic flame retardant is selected from any one of aluminum hydroxide and magnesium hydroxide;

[0015] The sphericity of the spherical inorganic flame retardant is 0.85-0.90;

[0016] The particle size distribution range of the spherical inorganic flame retardant is 10-120 nm.

[0017] Furthermore, the surface of the spherical inorganic flame retardant is coated with a silane coupling agent;

[0018] The silane coupling agent is selected from any one of silane coupling agent KH-540, silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570, and silane coupling agent KH-580.

[0019] Furthermore, the D50 of the flaky polyetheretherketone is 3-10 μm; and the average thickness of the flaky polyetheretherketone is 100-110 nm.

[0020] Furthermore, the aspect ratio of the fibrous polyetherketoneketone is 1:40-50.

[0021] Furthermore, the concentration of the dopamine solution is 6-8 g / L.

[0022] Furthermore, the step of adjusting the pH of the impregnation solution to be weakly alkaline comprises adjusting the pH of the impregnation solution to 7.8-8.0.

[0023] Furthermore, the heating and melting includes: rapidly heating to 334-338°C at a rate of 3.5-4.2°C / min, keeping warm for 10-12 minutes, and then slowly heating to 343-345°C at a rate of 0.2-0.4°C / min, and keeping warm for 10-15 minutes.

[0024] Furthermore, the cooling includes: rapidly cooling to 300-305°C at a rate of 4.5-6.5°C / min, keeping the temperature at rest for 10-15 minutes, and then slowly cooling to room temperature at a rate of 1.0-1.2°C / min. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to specific examples, which, however, are not intended to limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0026] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0027] Example 1

[0028] 20 parts by weight of spherical inorganic flame retardant, 20 parts of flaky polyetheretherketone, and 60 parts of fibrous polyetherketoneketone were mixed and poured into 400 parts of a 6 g / L dopamine solution. The mixture was ultrasonically dispersed at 60°C and 100 kHz for 10 minutes to obtain an impregnation solution.

[0029] The pH of the impregnation solution was adjusted to 7.8 with a 2% by mass sodium hydroxide solution, i.e., a weakly alkaline environment, and then the alkali-free glass fiber cloth was immersed in the impregnation solution. The impregnation was carried out at a temperature of 60° C. and an ultrasonic frequency of 100 kHz for 10 minutes. The ultrasonic treatment was stopped, and the impregnation was carried out for 2 hours. The impregnation material was then taken out to obtain the impregnation material.

[0030] The impregnated material was transferred into an oven and dried at 90°C to constant weight to obtain a dry impregnated material; the obtained dry impregnated material was then rapidly heated to 334°C at a rate of 3.5°C / min, kept warm for 10 minutes, and then slowly heated to 343°C at a rate of 0.2°C / min and kept warm for 10 minutes to melt the polyetheretherketone and polyetherketoneketone on the surface of the impregnated material; then the impregnated material was rapidly cooled to 300°C at a rate of 4.5°C / min, kept warm for 10 minutes, and then slowly cooled to room temperature at a rate of 1.0°C / min and discharged to obtain a low dielectric halogen-free flame-retardant glass fiber prepreg;

[0031] The spherical inorganic flame retardant is selected from aluminum hydroxide;

[0032] The sphericity of the spherical inorganic flame retardant is 0.85;

[0033] The particle size distribution range of the spherical inorganic flame retardant is 10-120 nm;

[0034] The surface of the spherical inorganic flame retardant is coated with a silane coupling agent;

[0035] The silane coupling agent is selected from silane coupling agent KH-540;

[0036] The D50 of the polyetheretherketone sheet is 3 μm; and the average thickness of the polyetheretherketone sheet is 100 nm;

[0037] The aspect ratio of the fibrous polyetherketoneketone is 1:40.

[0038] Example 2

[0039] 22 parts by weight of spherical inorganic flame retardant, 25 parts of flaky polyetheretherketone, and 70 parts of fibrous polyetherketoneketone were mixed and poured into 420 parts of a 7 g / L dopamine solution. The mixture was ultrasonically dispersed at 65°C and an ultrasonic frequency of 110 kHz for 12 minutes to obtain an impregnation solution.

[0040] The pH of the impregnation solution was adjusted to 7.9 with a 3% by mass sodium hydroxide solution, i.e., a weakly alkaline environment, and then the alkali-free glass fiber cloth was immersed in the impregnation solution. The impregnation was carried out at a temperature of 65° C. and an ultrasonic frequency of 110 kHz for 15 minutes. The ultrasonic treatment was stopped, and the impregnation was carried out for 3 hours. The impregnation material was then taken out to obtain the impregnation material.

[0041] The impregnated material was transferred into an oven and dried at 95°C to constant weight to obtain a dry impregnated material; the obtained dry impregnated material was then rapidly heated to 336°C at a rate of 3.8°C / min, kept warm for 11 minutes, and then slowly heated to 344°C at a rate of 0.3°C / min and kept warm for 12 minutes to melt the polyetheretherketone and polyetherketoneketone on the surface of the impregnated material; then the impregnated material was rapidly cooled to 302°C at a rate of 5.5°C / min, kept warm for 12 minutes, and then slowly cooled to room temperature at a rate of 1.1°C / min and discharged to obtain a low dielectric halogen-free flame-retardant glass fiber prepreg;

[0042] The spherical inorganic flame retardant is selected from aluminum hydroxide;

[0043] The sphericity of the spherical inorganic flame retardant is 0.88;

[0044] The particle size distribution range of the spherical inorganic flame retardant is 10-120 nm;

[0045] The surface of the spherical inorganic flame retardant is coated with a silane coupling agent;

[0046] The silane coupling agent is selected from silane coupling agent KH-550;

[0047] The D50 of the sheet-like polyetheretherketone is 6 μm; and the average thickness of the sheet-like polyetheretherketone is 105 nm;

[0048] The aspect ratio of the fibrous polyetherketoneketone is 1:45.

[0049] Example 3

[0050] 25 parts by weight of spherical inorganic flame retardant, 30 parts of flaky polyetheretherketone, and 80 parts of fibrous polyetherketoneketone were mixed and poured into 450 parts of 8 g / L dopamine solution. The mixture was ultrasonically dispersed at 70°C and 120 kHz for 15 minutes to obtain an impregnation solution.

[0051] The pH of the impregnation solution is adjusted to 8.0 with a sodium hydroxide solution having a mass fraction of 2-4%, i.e., a weakly alkaline environment, and then the alkali-free glass fiber cloth is immersed in the impregnation solution. After the impregnation is carried out at a temperature of 70° C. and an ultrasonic frequency of 120 kHz for 20 minutes, the ultrasonic treatment is stopped, and the impregnation is carried out at a temperature of 4 hours, and then the impregnation material is taken out to obtain the impregnation material;

[0052] The impregnated material was transferred into an oven and dried at 100°C to constant weight to obtain a dry impregnated material; the obtained dry impregnated material was then rapidly heated to 338°C at a rate of 4.2°C / min, kept warm for 12 minutes, and then slowly heated to 345°C at a rate of 0.4°C / min and kept warm for 15 minutes to melt the polyetheretherketone and polyetherketoneketone on the surface of the impregnated material; then the impregnated material was rapidly cooled to 305°C at a rate of 6.5°C / min, kept warm for 15 minutes, and then slowly cooled to room temperature at a rate of 1.2°C / min and discharged to obtain a low dielectric halogen-free flame-retardant glass fiber prepreg;

[0053] The spherical inorganic flame retardant is selected from aluminum hydroxide;

[0054] The sphericity of the spherical inorganic flame retardant is 0.90;

[0055] The particle size distribution range of the spherical inorganic flame retardant is 10-120 nm;

[0056] The surface of the spherical inorganic flame retardant is coated with a silane coupling agent;

[0057] The silane coupling agent is selected from silane coupling agent KH-560;

[0058] The D50 of the sheet-like polyetheretherketone is 10 μm; and the average thickness of the sheet-like polyetheretherketone is 110 nm;

[0059] The aspect ratio of the fibrous polyetherketoneketone is 1:50.

[0060] Example 4

[0061] Compared with Example 1, this embodiment differs in that the sphericity of the spherical inorganic flame retardant is 0.8, and other conditions remain unchanged.

[0062] Example 5

[0063] The present embodiment differs from the embodiment 1 in that spherical polyetheretherketone of equal mass is used instead of the flaky polyetheretherketone, and the D50 of the spherical polyetheretherketone is 3 μm and the sphericity is 0.85; the other conditions remain unchanged.

[0064] Example 6

[0065] The present embodiment differs from the embodiment 1 in that spherical polyetherketoneketone of equal mass is used instead of the fibrous polyetherketoneketone, and the D50 of the spherical polyetheretherketone is 5 μm and the sphericity is 0.86, while the other conditions remain unchanged.

[0066] Example 7

[0067] Compared with Example 1, this embodiment has the following differences:

[0068] The impregnated material was transferred into an oven and dried at 90°C to constant weight to obtain a dry impregnated material; the obtained dry impregnated material was then rapidly heated to 334°C at a rate of 3.5°C / min, kept warm for 10 minutes, and then rapidly heated to 343°C at a rate of 3.5°C / min and kept warm for 10 minutes to melt the polyetheretherketone and polyetherketoneketone on the surface of the impregnated material; then the impregnated material was rapidly cooled to 300°C at a rate of 4.5°C / min, kept warm for 10 minutes, and then slowly cooled to room temperature at a rate of 1.0°C / min and discharged to obtain a low dielectric halogen-free flame-retardant glass fiber prepreg;

[0069] The rest of the conditions remain unchanged.

[0070] Example 8 Compared with Example 1, this embodiment has the following differences: The impregnated material was transferred into an oven and dried at 90°C to constant weight to obtain a dry impregnated material; the obtained dry impregnated material was then rapidly heated to 334°C at a rate of 3.5°C / min, kept warm for 10 minutes, and then slowly heated to 343°C at a rate of 0.2°C / min and kept warm for 10 minutes to melt the polyetheretherketone and polyetherketoneketone on the surface of the impregnated material; then the material was rapidly cooled to room temperature at a rate of 4.5°C / min and discharged to obtain a low dielectric halogen-free flame-retardant glass fiber prepreg; the other conditions remained unchanged.

[0071] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg, characterized in that: The specific preparation steps include: By weight, 20-25 parts of spherical inorganic flame retardant, 20-30 parts of flaky polyetheretherketone, and 60-80 parts of fibrous polyetherketoneketone are mixed and dispersed in 400-450 parts of dopamine solution to obtain an impregnation solution; Adjusting the pH of the impregnation liquid to a weak alkaline state, and then impregnating the alkali-free glass fiber cloth in the impregnation liquid to obtain an impregnated material; After the impregnated material is dried, heated and melted, and cooled, a low dielectric halogen-free flame-retardant glass fiber prepreg is obtained.

2. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The spherical inorganic flame retardant is selected from any one of aluminum hydroxide and magnesium hydroxide; The sphericity of the spherical inorganic flame retardant is 0.85-0.90; The particle size distribution range of the spherical inorganic flame retardant is 10-120 nm.

3. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 2, characterized in that: The surface of the spherical inorganic flame retardant is coated with a silane coupling agent; The silane coupling agent is selected from any one of silane coupling agent KH-540, silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570, and silane coupling agent KH-580.

4. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The D50 of the flaky polyetheretherketone is 3-10 μm; and the average thickness of the flaky polyetheretherketone is 100-110 nm.

5. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The aspect ratio of the fibrous polyetherketoneketone is 1:40-50.

6. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The concentration of the dopamine solution is 6-8 g / L.

7. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The step of adjusting the pH of the impregnation solution to be weakly alkaline is as follows: adjusting the pH of the impregnation solution to be 7.8-8.

0.

8. The method for preparing a low dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The heating and melting comprises: rapidly heating to 334-338° C. at a rate of 3.5-4.2° C. / min, keeping the temperature for 10-12 minutes, and then slowly heating to 343-345° C. at a rate of 0.2-0.4° C. / min, and keeping the temperature for 10-15 minutes.

9. The method for preparing a low-dielectric halogen-free flame-retardant glass fiber prepreg according to claim 1, characterized in that: The cooling comprises: rapidly cooling to 300-305° C. at a rate of 4.5-6.5° C. / min, keeping the temperature at rest for 10-15 minutes, and then slowly cooling to room temperature at a rate of 1.0-1.2° C. / min.