Preparation method of high-dispersity silica powder

Abstract

The invention relates to the technical field of silica powder surface treatment, in particular to a preparation method of high-dispersity silica powder. Comprising the following steps: S1, taking fused silica powder as a raw material; carrying out ball milling by using a ball mill, and controlling the particle size to be 2-5 microns; s2, carrying out plasma pretreatment on the silica powder; the silica powder is put into a plasma cleaning machine for surface treatment; s3, carrying out hydrophobic modification on the silica powder; and modifying the silicon micropowder subjected to plasma treatment by using a silane coupling agent. The silicon micropowder is treated by plasma, the reaction environment is easy to realize, the operation is simple, the repeatability is high, and the treated silicon micropowder is high in water dispersibility. According to the invention, the silicon micro powder subjected to plasma treatment and the silane coupling agent are superposed for use, so that the hydrophobic effect is obvious, and the dispersity in the epoxy resin is improved. The method is easy to realize mechanical production and has important significance on industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of surface treatment of silica powder, and more specifically, the present invention relates to a method for preparing highly dispersible silica powder. Background Art

[0002] Silica powder is a commonly used filler, especially in modern polymer materials such as plastics, rubbers, coatings, copper clad laminates, and electronic packaging, and occupies a relatively large share in their applications. In order to better integrate silica powder with polymer polymers, it is necessary to modify the surface of silica powder. The purpose of modification is to change the original properties of the silica powder surface, that is, to change the polarity to non-polarity, thereby improving the affinity, compatibility, processing fluidity and dispersibility between the filler and the polymer polymer, enhancing the bonding force between the filler and the polymer polymer interface, improving the mechanical properties of the organic composite material, increasing the filling amount, and reducing the production cost.

[0003] Generally, silane coupling agents are used to hydrophobically modify silica powder, but it is difficult to achieve good hydrophobic effects in production, and thus it cannot achieve good compatibility with epoxy resins.

[0004] Therefore, we propose a method for preparing highly dispersible silica powder to solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a method for preparing highly dispersible silica powder to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solution: A method for preparing highly dispersible silica powder, including the following preparation methods:

[0007] Step S1: Use molten silica powder as the raw material;

[0008] Mill it using a ball mill, and control the particle size within 2 - 5 μm;

[0009] Step S2: Perform plasma pretreatment on the silica powder;

[0010] Put the silica powder into a plasma cleaner for surface treatment;

[0011] Step S3: Perform hydrophobic modification on the silica powder;

[0012] Modify the plasma-treated silica powder with a silane coupling agent.

[0013] In a preferred embodiment, step S1 further includes the following content:

[0014] Put the silica powder, ball mill in a ratio of 1:(1 - 5), and water into a ball mill tank for ball milling;

[0015] Its rotation speed is 200 r / min - 500 r / min, and ball milling makes the silica powder reach 2 μm - 5 μm.

[0016] Step S1 further includes the following content:

[0017] The silica content in the silica powder is 90% - 99%.

[0018] In a preferred embodiment, step S2 further includes the following content:

[0019] Put the silica powder into a plasma cleaner for 1 min - 3 min, and then obtain the plasma-treated silica powder.

[0020] Step S2 further includes the following content:

[0021] Put 1 g - 2 g of the silica powder into a quartz crucible and spread it flat, and then put it into a plasma cleaner.

[0022] In a preferred embodiment, step S3 further includes the following content:

[0023] Take an appropriate amount of the plasma-treated silica powder and put it into a beaker, prepare an ethanol aqueous solution, mix it with the silica powder to obtain a silica powder mixed solution.

[0024] Step S3 further includes the following content:

[0025] Drop glacial acetic acid into the silica powder mixed solution, adjust the pH to 3 - 5, and then use an ultrasonic disperser to ultrasonically disperse for 15 min - 20 min;

[0026] Step S3 further includes the following content:

[0027] Drop the silane coupling agent KH550 into the ultrasonically dispersed silica powder mixed solution, and the dosage of KH550 is 3% - 5% of the silica powder. Then, use an ultrasonic disperser to ultrasonically disperse the mixed solution for 3 min - 5 min.

[0028] Step S3 further includes the following content:

[0029] Put the silica powder mixed solution added with the silane coupling agent KH550 into a magnetic stirrer and stir it. The temperature is 90°C - 110°C, the stirring rate is 300 - 500 r / min, and the stirring time is 1 h - 3 h;

[0030] Finally, filter it by suction and dry it to obtain highly dispersed silica powder.

[0031] The technical effects and advantages of the present invention:

[0032] The present invention relates to plasma-treated silica powder, which has an easily achievable reaction environment, simple operation, strong repeatability, and high water dispersibility of the treated silica powder.

[0033] The silica powder treated by plasma in the present invention is used in combination with a silane coupling agent, and the hydrophobic effect is remarkable, improving the dispersibility in epoxy resin.

[0034] The present invention is easily realized in mechanical production and is of great significance to industrial production. Description of the Drawings

[0035] Figure 1 is the internal structure diagram of the plasma cleaner of the present invention;

[0036] Figure 2 is the schematic diagram of the zeta potential of the silica powder before and after plasma treatment of the present invention;

[0037] Figure 3 is the FT-IR infrared spectrum diagram of the original powder, the powder after plasma treatment, and the powder after hydrophobic modification of the present invention;

[0038] Figure 4 is the contact angle table diagram of the original powder and the powder after hydrophobic modification of the present invention. Detailed Embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Refer to Figures 1-4 and it should be particularly noted that: the attached Figure 1 is the internal structure diagram of the plasma cleaner. Since there are many pores on each surface, so that the plasma can be emitted and the powder is uniformly treated.

[0041] A preparation method of highly dispersible silica powder;

[0042] Example 1:

[0043] Step S1: Using molten silica powder as the raw material, put the silica powder and the ball mill into the ball mill tank at a ratio of 1:(1 - 5) together with water, and rotate at a speed of 200 r / min - 500 r / min to ball mill it to 2 μm - 5 μm.

[0044] Step S2: Put 1.5 g of silica powder into the plasma cleaner for plasma treatment, set the power to 80 W, and the treatment time to 2 min, and perform the treatment in multiple batches;

[0045] Step S3: Take 5 g of the plasma-treated silicon micropowder in a beaker, add an ethanol aqueous solution with a volume ratio of 1:9, adjust the pH to 4 with glacial acetic acid, and ultrasonically disperse for 15 min;

[0046] Add KH550 to the above mixed solution, with the dosage being 3% of the silicon micropowder dosage, ultrasonically disperse for 5 min, place the solution on a magnetic stirrer, at a temperature of 100 °C, a rotation speed of 400 r / min, and stir for 2 h. Finally, filter and dry the solution.

[0047] Example 2:

[0048] Step S1: Using molten silicon micropowder as the raw material, put the silicon micropowder and the ball mill into the ball mill tank at a ratio of 1:(1 - 5) together with water, with a rotation speed of 200 r / min - 500 r / min, and ball mill until it reaches 2 μm - 5 μm.

[0049] Step S2: Put 1.5 g of the silicon micropowder into a plasma cleaner for plasma treatment, set the power to 80 W, the treatment time to 2 min, and perform the treatment in multiple batches;

[0050] Step S3: Take 5 g of the plasma-treated silicon micropowder in a beaker, add an ethanol aqueous solution with a volume ratio of 1:9, adjust the pH to 4 with glacial acetic acid, and ultrasonically disperse for 15 min;

[0051] Add KH550 to the above mixed solution, with the dosage being 4% of the silicon micropowder dosage, ultrasonically disperse for 5 min, place the solution on a magnetic stirrer, at a temperature of 100 °C, a rotation speed of 400 r / min, and stir for 2 h. Finally, filter and dry the solution.

[0052] Example 3:

[0053] Step S1: Using molten silicon micropowder as the raw material, put the silicon micropowder and the ball mill into the ball mill tank at a ratio of 1:(1 - 5) together with water, with a rotation speed of 200 r / min - 500 r / min, and ball mill until it reaches 2 μm - 5 μm.

[0054] Step S2: Put 1.5 g of the silicon micropowder into a plasma cleaner for plasma treatment, set the power to 80 W, the treatment time to 2 min, and perform the treatment in multiple batches;

[0055] Step S3: Take 5 g of the plasma-treated silicon micropowder in a beaker, add an ethanol aqueous solution with a volume ratio of 1:9, adjust the pH to 4 with glacial acetic acid, and ultrasonically disperse for 15 min;

[0056] Add KH550 to the above mixed solution, with the dosage being 5% of the silicon micropowder dosage, ultrasonically disperse for 5 min, place the solution on a magnetic stirrer, at a temperature of 100 °C, a rotation speed of 400 r / min, and stir for 2 h. Finally, filter and dry the solution.

[0057] And it should be particularly noted that KH550 mentioned above is the silane coupling agent KH-550.

[0058] Based on the above, the following conclusions can be drawn:

[0059] Addition amount of KH550 Measuring contact angle of powder Example 1 3％ 90.4° Example 2 4％ 129.6° Example 3 5％ 86.5°

[0060] Summary:

[0061] In Example 1, the contact angle of the hydrophobically modified powder was measured to be 90.4°.

[0062] In Example 2, the contact angle of the hydrophobically modified powder was measured to be 129.6°.

[0063] In Example 3, the contact angle of the hydrophobically modified powder was measured to be 86.5.

[0064] From the above table, we can obtain that: with the change of the addition amount of KH550, the contact angle of the powder measured will also change accordingly. When the addition amount of KH550 is 4%, the contact angle of the powder measured can reach 129.6°.

[0065] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing highly dispersible silicon micropowder, characterized in that; The invention comprises the following preparation methods: Step S1: using molten silicon powder as raw material; The product is ball milled in a practical ball mill, and the particle size is controlled at 2-5 μm; Step S2: performing plasma pretreatment on silicon micropowder; Place silicon micropowder into a plasma cleaning machine for surface treatment; Step S3: hydrophobic modification of silicon micropowder; The plasma treated silicon micropowder is modified with a silane coupling agent.

2. The method for preparing highly dispersible silicon micropowder according to claim 1, characterized in that: Step S1 also includes the following contents: Put the silicon micro powder, ball mill and water in a ratio of 1: (1-5) into a ball mill to make spherical graphite; The rotation speed is 200r / min-500r / min, and the ball milling makes the silicon micropowder reach 2μm-5μm.

3. The method for preparing highly dispersible silicon micropowder according to claim 1, characterized in that: Step S1 also includes the following contents: The silicon dioxide content in silicon micropowder is 90%-99%.

4. The method for preparing highly dispersible silicon micropowder according to claim 1, characterized in that: Step S2 also includes the following contents: The silicon micropowder is placed in a plasma cleaning machine for 1 min to 3 min, and then the silicon micropowder after plasma treatment is obtained.

5. The method for preparing highly dispersible silicon micropowder according to claim 3, characterized in that: Step S2 also includes the following contents: Put 1g-2g of silicon micropowder into a quartz crucible and spread it flat, then put it into a plasma cleaning machine.

6. The method for preparing highly dispersible silicon micropowder according to claim 1, characterized in that: Step S3 also Includes the following: An appropriate amount of plasma-treated silicon micropowder is put into a beaker, and an ethanol aqueous solution is prepared and mixed with the silicon micropowder to obtain a silicon micropowder mixed solution.

7. The method for preparing highly dispersible silicon micropowder according to claim 6, characterized in that: Step S3 also Includes the following: Add glacial acetic acid dropwise into the silica powder mixed solution, adjust the pH to 3-5, and then use an ultrasonic disperser to ultrasonically disperse for 15-20 minutes.

8. The method for preparing highly dispersible silicon micropowder according to claim 7, characterized in that: Step S3 also Includes the following: The silane coupling agent KH550 is added dropwise to the ultrasonically dispersed silicon micropowder mixed solution, and the amount of KH550 is 3%-5% of the silicon micropowder. The mixed solution is then ultrasonically dispersed for 3min-5min using an ultrasonic disperser.

9. The method for preparing highly dispersible silicon micropowder according to claim 8, characterized in that: Step S3 also Includes the following: Put the silicon powder mixed solution with silane coupling agent KH550 added into a magnetic stirrer and stir at a temperature of 90°C-110°C, a stirring rate of 300-500r / min, and a stirring time of 1h-3h; Finally, the mixture is filtered and dried to obtain highly dispersed silicon micropowder.

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