Environment-friendly grinding and polishing liquid based on biodegradable material and preparation method thereof

Abstract

The application provides an environment-friendly polishing liquid based on biodegradable materials and a preparation method thereof. The polishing liquid comprises the following components in percentage by weight: abrasive 0.5-2%, dispersant 1-5%, thickening agent 0.5-2%, oxidizing agent 1-5%, and the balance is deionized water, and the pH value is adjusted to 7-11 by a pH value adjusting agent. The polishing liquid prepared by the application has a high material removal rate and a low surface roughness, indicating that the polishing efficiency is high and the polishing effect is good, and the dispersant, the thickening agent and the oxidizing agent used are all green and environment-friendly materials and can be biodegraded, thereby reducing the risk of pollution to the environment caused by traditional polishing liquids.

Description

Technical Field

[0001] This invention belongs to the field of polishing fluid technology, and particularly relates to an environmentally friendly grinding and polishing fluid based on biodegradable materials and its preparation method. Background Technology

[0002] Polishing slurry is a chemical mechanical polishing liquid material used in the surface treatment of materials. It is mainly used to remove unevenness and damaged layers on the surface of materials, and improve the smoothness and gloss of the surface. It is usually composed of carrier reagents, abrasives, additives and other substances, and is currently widely used in the fields of sapphire, ceramics, semiconductors, metals and other materials.

[0003] However, reports on existing technologies reveal that conventional polishing slurries often use harmful substances such as sulfur and chlorine as additives to achieve high polishing efficiency and effects. These substances may generate toxic gases during use or remain in waste liquids and are difficult to degrade, causing significant environmental pollution. Therefore, with the continuous development of technology, the preparation of environmentally friendly polishing slurries is an inevitable requirement.

[0004] Polishing fluids still suffer from poor dispersibility and easy agglomeration during storage, resulting in poor stability and short lifespan. This also leads to low material removal rate and poor polishing effect on the processed parts. Therefore, further improvements are still needed.

[0005] In view of the problems existing in the prior art, how to provide a polishing fluid with high polishing efficiency, good treatment effect and environmental protection without pollution is the problem that this invention urgently needs to solve. Summary of the Invention

[0006] The purpose of this invention is to provide an environmentally friendly grinding and polishing fluid based on biodegradable materials and its preparation method, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides an environmentally friendly grinding and polishing slurry based on biodegradable materials, characterized in that the polishing slurry contains the following components by weight percentage: 0.5-2% abrasive, 1-5% dispersant, 0.5-2% thickener, 1-5% oxidant, and the balance being deionized water;

[0008] The dispersant is modified hemicellulose;

[0009] The thickener is an anionic waterborne polyurethane;

[0010] The environmentally friendly grinding and polishing fluid based on biodegradable materials has its pH adjusted to 7-11 using a pH adjuster.

[0011] As a further improvement, the modified hemicellulose is prepared by reacting hemicellulose with maleic anhydride.

[0012] As a further improvement, the synthesis of the modified hemicellulose includes the following steps:

[0013] (1) After the corn stalks are naturally air-dried, they are crushed and filtered through a 40-60 mesh filter. The filtered raw material is added to an alkaline solution and stirred and mixed at 60-90℃. Then it is cooled to room temperature and filtered to obtain the filtrate.

[0014] (2) Add acidic solution to the filtrate to adjust the pH to 5-6, centrifuge to separate, collect the liquid phase, concentrate by rotary evaporation, then transfer to a beaker, add anhydrous ethanol, let stand for 2-5 hours, filter, collect the solid, evaporate the filtrate by rotary evaporation again, add anhydrous ethanol and let stand, collect a second time, and then process to obtain hemicellulose.

[0015] (3) Add hemicellulose to an organic solvent and stir to dissolve at 70-90℃. Then cool down to 40-60℃, add catalyst and maleic anhydride, and continue the reaction for 2-5 hours. After the reaction is completed, perform post-treatment to obtain modified hemicellulose.

[0016] As a further improvement, the catalyst is brominated succinimide.

[0017] As a further improvement, the pH value of the anionic waterborne polyurethane is 6-9.

[0018] As a further improvement, the pH value of the anionic waterborne polyurethane is 7-8.

[0019] As a further improvement, the abrasive is at least one selected from diamond, cubic boron nitride, silicon carbide, cerium oxide, silicon dioxide, and aluminum oxide.

[0020] For better polishing results, the abrasive is preferably diamond abrasive.

[0021] As a further improvement, the abrasive has an average particle size of 50 nm to 50 μm.

[0022] As a further improvement, the oxidant is at least one of hydrogen peroxide, sodium percarbonate, and calcium peroxide.

[0023] As a further improvement, the pH adjuster is at least one of malic acid and potassium pyrophosphate.

[0024] This invention also provides a method for preparing an environmentally friendly grinding and polishing slurry based on biodegradable materials, characterized by comprising the following steps:

[0025] Mix the abrasive and deionized water evenly according to the weight proportions, then add the dispersant, thickener and oxidant and continue stirring and mixing. Adjust the pH to 7-11 with a pH adjuster to obtain an environmentally friendly grinding and polishing fluid based on biodegradable materials.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention provides an environmentally friendly grinding and polishing slurry based on biodegradable materials and its preparation method. The resulting polishing slurry has a high material removal rate, indicating high polishing efficiency, and a low surface roughness, indicating a smooth surface of the processed workpiece and good polishing effect. Furthermore, the dispersant, thickener, and oxidant used are all green and environmentally friendly materials that are biodegradable, reducing the risk of environmental pollution caused by traditional polishing slurries. Detailed Implementation

[0028] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0029] In the following examples, except for the modified hemicellulose, all other compound monomers and related reagents used were commercially available. The anionic waterborne polyurethane was purchased from Greenlink (Jining) Chemical Technology Co., Ltd., model number 9190; the diamond abrasive was sourced from our own production; and the corn stalks were sourced from rural fields in Zhengzhou, Henan. The cationic waterborne polyurethane was purchased from Zibo Baowei New Material Technology Co., Ltd., model number BW-8700.

[0030] The synthesis of modified hemicellulose includes the following steps:

[0031] (1) After the corn stalks are naturally air-dried, they are crushed and filtered through a 50-mesh filter. Take 20g of the filtered raw material and add it to 200mL of 60g / L potassium hydroxide solution. Stir and mix at 80℃ for 2h, then cool to room temperature and filter to obtain the filtrate.

[0032] (2) Add acetic acid to the filtrate to adjust the pH to 5.5, centrifuge to separate, collect the liquid phase, and then concentrate it to 30 mL by rotary evaporation. Then transfer it to a beaker, add 100 mL of anhydrous ethanol, let stand for 3 h, filter, collect the solid, evaporate the filtrate by rotary evaporation again, add 100 mL of anhydrous ethanol, let stand, collect a second time, and then place the solid in a freeze dryer to dry for 12 h to obtain hemicellulose.

[0033] (3) Dissolve 5g of hemicellulose in a mixture of 100mL N,N-dimethylformamide and 15g of lithium chloride, stir at 85℃ to dissolve, then cool to 55℃, add 1.5g of bromosuccinimide and 20g of maleic anhydride, continue the reaction for 3h, filter, wash with anhydrous ethanol, and vacuum dry for 24h to obtain modified hemicellulose.

[0034] The preparation methods of Examples 1-3 and Comparative Examples 1-2 include the following steps:

[0035] Mix the abrasive and deionized water evenly according to the weight proportions, then add the dispersant, thickener and oxidant and continue stirring and mixing. Adjust the pH to 10 with a pH adjuster to obtain an environmentally friendly grinding and polishing fluid based on biodegradable materials.

[0036] The components and their contents used in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1 below:

[0037] Table 1

[0038]

[0039]

[0040] The environmentally friendly grinding and polishing slurries based on biodegradable materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested for material removal rate and surface roughness performance. The test methods are as follows:

[0041] Material removal rate: After weighing the sapphire sheet, it was adhered to a ceramic disc using solid wax and placed in a polishing machine for polishing (test conditions: rotation speed 80 r / min; pressure: 30 kg; time: 900 s; flow rate: 4 mL / min). After polishing, the sapphire sheet was removed, cleaned with ethanol and water in sequence, allowed to air dry, weighed, and the material removal rate was calculated according to the following formula:

[0042] MRR=(Δm) / ρtS;

[0043] Δm is the difference between the two weighings (g), and ρ is the density of sapphire (g / cm³). 3 ), t is the polishing time (min), and S is the area of ​​the sapphire wafer (cm²). 2 );

[0044] Surface roughness: Select 5 points around the perimeter and center of the sapphire wafer, and use a surface roughness meter to test the roughness of each of the 5 points. Measure each point 3 times and take the average roughness.

[0045] The test results are shown in Table 2, as follows:

[0046] Table 2

[0047] Material removal rate (μm / min) Surface roughness (nm) Example 1 1.1 114 Example 2 1.6 96 Example 3 1.4 102 Comparative Example 1 0.3 158 Comparative Example 2 0.7 143

[0048] As can be seen from Example 2 and Comparative Example 1 in Table 2, compared with the polishing liquid prepared using unmodified hemicellulose, the polishing liquid prepared using modified hemicellulose has a higher material removal rate and lower surface roughness, indicating that the modified hemicellulose has better dispersibility, making the polishing liquid less prone to agglomeration and more stable. Moreover, hemicellulose is derived from corn stalks, is green and environmentally friendly, biodegradable, and will not cause environmental pollution.

[0049] As can be seen from Example 2 and Comparative Example 2, compared with the polishing liquid prepared using cationic waterborne polyurethane, the polishing liquid prepared using anionic waterborne polyurethane has a higher material removal rate and a lower surface roughness. This indicates that the application of anionic waterborne polyurethane as a thickener in the preparation of this polishing liquid can make the material have higher adhesion, improve polishing efficiency, and also conform to the concept of green environmental protection, without causing pollution to the environment.

[0050] The test results of Examples 1-3 show that the polishing liquid prepared by the preparation method provided by the present invention has a high material removal rate when applied to workpiece processing, indicating high polishing efficiency. It also has a low surface roughness, indicating that the surface of the processed workpiece is smooth and the polishing effect is good. Furthermore, the dispersant, thickener and oxidant used are all green and environmentally friendly materials that can be biodegraded, reducing the risk of pollution to the environment caused by traditional polishing liquids.

[0051] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly polishing liquid based on a biodegradable material, characterized by comprising: a biodegradable material; a surfactant; and a solvent. The polishing fluid contains the following components by weight percentage: 0.5-2% abrasive, 1-5% dispersant, 0.5-2% thickener, 1-5% oxidant, and the balance being deionized water; The dispersant is modified hemicellulose; The thickener is an anionic waterborne polyurethane; The environmentally friendly grinding and polishing fluid based on biodegradable materials has its pH adjusted to 7-11 using a pH adjuster. The abrasive is diamond; The synthesis of the modified hemicellulose includes the following steps: (1) After the corn stalks are naturally air-dried, they are crushed and filtered through a 40-60 mesh filter. The filtered raw material is added to an alkaline solution and stirred at 60-90°C. Then it is cooled to room temperature and filtered to obtain the filtrate. (2) Add acidic solution to the filtrate, adjust the pH to 5-6, centrifuge, collect the liquid phase, concentrate by rotary evaporation, then transfer to a beaker, add anhydrous ethanol, let stand for 2-5 hours, filter, collect the solid, evaporate the filtrate by rotary evaporation again, add anhydrous ethanol, let stand, collect a second time, and then process to obtain hemicellulose. (3) Add hemicellulose to an organic solvent and stir to dissolve at 70-90°C. Then cool to 40-60°C, add catalyst and maleic anhydride, and continue the reaction for 2-5 hours. After the reaction is completed, perform post-treatment to obtain modified hemicellulose.

2. The eco-friendly abrasive polishing solution based on biodegradable material according to claim 1, characterized in that, The pH value of the anionic waterborne polyurethane is 6-9.

3. The environmentally friendly grinding and polishing fluid based on biodegradable materials according to claim 1, characterized in that, The pH value of the anionic waterborne polyurethane is 7-8.

4. The environmentally friendly grinding and polishing fluid based on biodegradable materials according to claim 1, characterized in that, The abrasive has an average particle size of 50 nm to 50 μm.

5. The environmentally friendly grinding and polishing fluid based on biodegradable materials according to claim 1, characterized in that, The oxidant is at least one of hydrogen peroxide, sodium percarbonate, and calcium peroxide.

6. The environmentally friendly grinding and polishing fluid based on biodegradable materials according to claim 1, characterized in that, The pH adjuster is at least one of malic acid and potassium pyrophosphate.

7. A method for preparing an environmentally friendly grinding and polishing slurry based on biodegradable materials according to any one of claims 1-6, characterized in that, The process includes the following steps: Mix the abrasive and deionized water evenly according to the weight proportions, then add the dispersant, thickener, and oxidant and continue stirring and mixing. Adjust the pH to 7-11 with a pH adjuster to obtain an environmentally friendly grinding and polishing fluid based on biodegradable materials.

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