Preparation method of flame-retardant modified silica powder for copper-clad plate

Abstract

The invention discloses a preparation method of flame-retardant modified silica powder for a copper-clad plate. The preparation method comprises the following steps: (1) preparing raw materials; (2) premixing; (3) flame-retardant modification reaction; and (4) post-treatment. The invention belongs to the technical field of silica powder application, and particularly relates to a preparation method of flame-retardant modified silica powder for a copper-clad plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of the application of silica powder, and specifically refers to a preparation method of flame-retardant modified silica powder for copper clad laminates. Background Art

[0002] At present, with the booming development of the electronic information industry, as a key basic material for printed circuit boards, the performance of copper clad laminates directly affects the quality and stability of electronic products. As an important additive for copper clad laminates, flame-retardant modified silica powder plays an indispensable role in improving the flame retardancy, electrical properties, mechanical properties, etc. of copper clad laminates. However, there are many problems to be solved urgently in the traditional preparation methods of flame-retardant modified silica powder on the market at present.

[0003] Although the method of simple physical mixing is easy to operate, it only simply mixes the flame retardant and silica powder, and there is a lack of effective chemical bonding between the two. This leads to that in the actual use process of copper clad laminates, especially in the face of harsh environments such as high temperature and high humidity, the flame retardant is extremely easy to fall off from the surface of silica powder, resulting in a rapid attenuation of the flame retardant effect and being unable to provide lasting and stable fire protection for copper clad laminates.

[0004] Conventional chemical modification methods often need to carry out reactions under harsh conditions of high temperature (usually exceeding 200°C) and high pressure (generally greater than 5 MPa). Such conditions not only have extremely high requirements for reaction equipment, greatly increasing the equipment purchase cost and maintenance cost, but also consume a large amount of energy during the production process, further increasing the production cost. At the same time, the complex process also increases the operation difficulty and safety risk during the production process, which is not conducive to large-scale industrial production.

[0005] In addition, the silica powder obtained by traditional preparation methods has poor performance in terms of particle size distribution and dispersibility. Uneven particle size distribution will lead to difficult uniform dispersion of silica powder during the production process of copper clad laminates, thereby affecting the overall performance consistency of copper clad laminates. Poor dispersibility is prone to cause agglomeration of silica powder in copper clad laminates, reducing the synergistic effect between silica powder and other materials, making the electrical properties, mechanical properties, etc. of copper clad laminates unable to reach the ideal state and difficult to meet the requirements of modern electronic products for high-performance copper clad laminates. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a preparation method of flame-retardant modified silica powder for copper clad laminates.

[0007] In order to achieve the above functions, the technical solution adopted by the present invention is as follows:

[0008] A preparation method of flame-retardant modified silica powder for copper clad laminates includes the following steps:

[0009] (1) Raw material preparation: 45 g - 65 g of silica powder, 45 g - 65 g of phosphorus-nitrogen based composite flame retardant, 2 g - 3 g of γ-aminopropyltriethoxysilane, and 0.5 g - 0.8 g of dibutyltin dilaurate;

[0010] (2) Premixing: Add silica powder into a three-necked flask containing 200 mL - 400 mL of absolute ethanol, ultrasonically disperse it for 15 - 40 minutes under the condition of ultrasonic power of 200 W - 300 W, add γ-aminopropyltriethoxysilane, and stir and react at a speed of 150 r / min - 350 r / min in a constant temperature water bath at 50 °C - 70 °C for 1 - 2 hours. After the reaction, centrifuge (rotation speed is 4000 r / min - 5000 r / min, time is 10 - 20 minutes), and wash with absolute ethanol 3 - 5 times, then dry in a vacuum drying oven at 80 °C - 100 °C for 5 - 7 hours to obtain surface-treated silica powder;

[0011] (3) Flame retardant modification reaction: Add the surface-treated silica powder and the phosphorus-nitrogen based composite flame retardant into a reaction kettle, then add dibutyltin dilaurate, and stir and react at 180 r / min - 200 r / min at 130 °C - 140 °C for 4.5 - 5 hours;

[0012] (4) Post-treatment: Cool the product to room temperature and then crush it, and pass through a 350 - 400 mesh sieve to obtain flame retardant modified silica powder.

[0013] Preferably, the silica powder is a high-purity silica powder with a purity ≥ 99% and a particle size of 1 - 5 μm; the phosphorus content in the phosphorus-nitrogen based composite flame retardant is 15 - 20%, and the nitrogen content is 10 - 15%; the purity of γ-aminopropyltriethoxysilane is ≥ 98%; the purity of dibutyltin dilaurate is ≥ 95%.

[0014] The beneficial effects obtained by the present invention are as follows:

[0015] 1. Through the unique preparation process of the present invention, the chemical bond tight combination between the flame retardant and the silica powder is successfully realized. This strong interaction makes the attachment of the flame retardant on the surface of the silica powder more firm. During the actual use of the copper clad laminate, even in the face of complex and harsh environmental conditions, the flame retardant is not easy to fall off. After testing, when the flame retardant modified silica powder prepared by this method is applied to the copper clad laminate, its flame retardant performance reaches V-0 level in the UL94 test, which has been significantly improved compared with the silica powder prepared by the traditional method (V-1 level), effectively improving the fire protection level of the copper clad laminate and providing more reliable guarantee for the safe use of electronic products.

[0016] 2. This preparation method abandons the traditional high-temperature and high-pressure reaction conditions. The reaction can proceed smoothly at a relatively mild temperature (120 °C) and normal pressure. This not only reduces the requirements for reaction equipment, eliminating the need to purchase expensive high-temperature and high-pressure resistant equipment and reducing equipment investment costs, but also significantly reduces energy consumption during the production process, further reducing production costs. At the same time, the simplified process operation flow also reduces the complexity and error rate of manual operations, improves production efficiency, and is conducive to the promotion of large-scale industrial production.

[0017] 3. This method uses environmentally friendly chemical reagents, such as γ-aminopropyltriethoxysilane with a purity ≥ 98% as a coupling agent and dibutyltin dilaurate with a purity ≥ 95% as a catalyst. These reagents do not produce toxic and harmful by-products during the reaction process, reducing environmental pollution. Compared with some volatile and toxic chemical reagents used in traditional preparation methods, this method better meets the requirements of today's society for green environmental protection and is conducive to sustainable development.

[0018] 4. The silica powder prepared by this method exhibits excellent performance in terms of particle size distribution and dispersibility. By precisely controlling the reaction conditions and post-treatment processes, the obtained silica powder has an average particle size between 2 - 4 μm, with a uniform particle size distribution. During the production process of copper clad laminates, it can be evenly dispersed in the resin matrix, effectively avoiding the occurrence of agglomeration phenomena. The good dispersibility enables the silica powder to fully exert its synergistic effect with other materials, significantly improving the electrical properties of copper clad laminates, such as the dielectric constant being reduced to 3.8 - 4.2 (1 MHz), and at the same time enhancing the mechanical properties of copper clad laminates, with a tensile strength reaching 140 - 150 MPa, providing high-quality raw materials for the preparation of high-performance copper clad laminates. Detailed implementation methods

[0019] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1

[0021] A preparation method of flame-retardant modified silica powder for copper clad laminates, comprising the following steps:

[0022] (I) Raw material preparation: Select 50 g of silica powder with a purity of 99.5% and a particle size of 3 μm; 10 g of a phosphorus-nitrogen based composite flame retardant, with a phosphorus element content of 18% and a nitrogen element content of 12%; 2.5 g of γ-aminopropyltriethoxysilane with a purity of 98.5%; 0.6 g of dibutyltin dilaurate with a purity of 96%;

[0023] (II) Premixing: Add silica fume into a three-necked flask containing 250 mL of absolute ethanol, disperse it for 25 minutes under an ultrasonic power of 220 W, then add γ-aminopropyltriethoxysilane, and stir and react at a speed of 180 r / min in a constant temperature water bath at 55 °C for 1.8 hours. After the reaction, centrifuge at 4500 r / min for 12 minutes, wash it 4 times with absolute ethanol, and dry it in a vacuum drying oven at 90 °C for 6 hours to obtain surface-treated silica fume;

[0024] (III) Flame-retardant modification reaction: Add the surface-treated silica fume and the phosphorus-nitrogen composite flame retardant into a reaction kettle, then add dibutyltin dilaurate, and stir and react at 180 r / min at 130 °C for 4.5 hours;

[0025] (IV) Post-treatment: After the product is cooled to room temperature, it is crushed and passed through a 350-mesh sieve to obtain flame-retardant modified silica fume.

[0026] Example 2

[0027] A preparation method of flame-retardant modified silica fume for copper clad laminates, comprising the following steps:

[0028] (I) Raw material preparation: Select 60 g of silica fume with a purity of 99.8% and a particle size of 4 μm; 12 g of phosphorus-nitrogen composite flame retardant, with a phosphorus element content of 16% and a nitrogen element content of 13%; 3 g of γ-aminopropyltriethoxysilane with a purity of 99%; 0.7 g of dibutyltin dilaurate with a purity of 97%;

[0029] (II) Premixing: Add silica fume into a three-necked flask containing 300 mL of absolute ethanol, disperse it for 30 minutes under an ultrasonic power of 250 W, then add γ-aminopropyltriethoxysilane, and at 60 °C

[0030] in a constant temperature water bath, stir and react at a speed of 200 r / min for 2 hours. After the reaction, centrifuge at 5000 r / min for 15 minutes, wash it 5 times with absolute ethanol, and dry it in a vacuum drying oven at 100 °C for 7 hours to obtain surface-treated silica fume;

[0031] (III) Flame-retardant modification reaction: Add the surface-treated silica fume and the phosphorus-nitrogen composite flame retardant into a reaction kettle, then add dibutyltin dilaurate, and stir and react at 200 r / min at 140 °C for 5 hours;

[0032] (IV) Post-treatment: After the product is cooled to room temperature, it is crushed and passed through a 400-mesh sieve to obtain flame-retardant modified silica fume.

[0033] Detection data

[0034]

[0035] As can be seen from the above table, through Example 1 and Example 2, it can be seen that the flame-retardant modified silica powder obtained by using the preparation method of the present invention, after being applied to the copper clad laminate, both reach the V-0 level in the UL94 test. This fully proves that this method can effectively enhance the binding force between the silica powder and the flame retardant, enabling the copper clad laminate to have more excellent fire resistance performance and providing more reliable safety protection for electronic products in dangerous situations such as fires.

[0036] Judging from the average particle size data, the average particle size of Example 1 is 2.5 μm, and that of Example 2 is 3 μm, with a more uniform particle size distribution. In terms of the dispersibility in the copper clad laminate, the silica powder prepared by this method shows a uniform dispersion state, while the silica powder prepared by the traditional method has obvious agglomeration phenomena. This indicates that this preparation method can effectively improve the powder properties of the silica powder, making it easier to disperse during the production process of the copper clad laminate and being conducive to improving the overall performance stability of the copper clad laminate.

[0037] In terms of the dielectric constant and tensile strength of the copper clad laminate, the dielectric constant of Example 1 is 3.9 (1 MHz), and the tensile strength is 145 MPa; the dielectric constant of Example 2 is 4 (1 MHz), and the tensile strength is 148 MPa. Compared with the dielectric constant (4.5 - 5.0) and tensile strength (120 - 130 MPa) of the copper clad laminate after applying the silica powder prepared by the traditional method, the silica powder prepared by this method can effectively reduce the dielectric constant of the copper clad laminate and increase the tensile strength. This means that using the silica powder prepared by this method can improve the electrical and mechanical properties of the copper clad laminate, meet the requirements of modern electronic products for high-performance copper clad laminates, and has good application prospects and market value.

[0038] The above describes the present invention and its implementation manners. This description is not restrictive, and what is shown is only one of the implementation manners of the present invention. The actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention creation, design structurally similar ways and embodiments to this technical solution without creative efforts, they should all fall within the protection scope of the present invention.

Claims

1. A preparation method of flame-retardant modified silica powder for copper clad laminate, characterized in that, It includes the following steps: (1) Raw material preparation: 45 g - 65 g of silica powder, 45 g - 65 g of phosphorus-nitrogen based composite flame retardant, 2 g - 3 g of γ-aminopropyltriethoxysilane, and 0.5 g - 0.8 g of dibutyltin dilaurate; (2) Premixing: Add silica powder into a three-necked flask containing 200 mL - 400 mL of absolute ethanol, ultrasonically disperse for 15 - 40 minutes under the condition of ultrasonic power of 200 W - 300 W, add γ-aminopropyltriethoxysilane, and stir and react at a rotation speed of 150 r / min - 350 r / min in a constant temperature water bath at 50°C - 70°C for 1 - 2 hours. After the reaction, carry out centrifugal separation (rotation speed is 4000 r / min - 5000 r / min, time is 10 - 20 minutes), and wash with absolute ethanol for 3 - 5 times, then dry in a vacuum drying oven at 80°C - 100°C for 5 - 7 hours to obtain surface-treated silica powder; (3) Flame retardant modification reaction: Add the surface-treated silica powder and the phosphorus-nitrogen based composite flame retardant into a reaction kettle, then add dibutyltin dilaurate, and stir and react at 130°C - 140°C at a rotation speed of 180 r / min - 200 r / min for 4.5 - 5 hours; (4) Post-treatment: Cool the product to room temperature and then crush it, and pass through a 350 - 400 mesh sieve to obtain flame retardant modified silica powder.

2. A preparation method of flame-retardant modified silica powder for copper clad laminates according to claim 1, characterized in that, The silica powder selected is high-purity silica powder with a purity of ≥99% and a particle size of 1 - 5 μm; the phosphorus content in the phosphorus-nitrogen based composite flame retardant is 15 - 20%, and the nitrogen content is 10 - 15%; the purity of γ-aminopropyltriethoxysilane is ≥98%; the purity of dibutyltin dilaurate is ≥95%.

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