Environment-friendly grinding and polishing solution based on biodegradable material and preparation method of environment-friendly grinding and polishing solution

Abstract

The invention provides an environment-friendly grinding and polishing solution based on a biodegradable material and a preparation method of the environment-friendly grinding and polishing solution. The polishing solution comprises the following components in percentage by weight: 0.5-2% of an abrasive material, 1-5% of a dispersing agent, 0.5-2% of a thickening agent, 1-5% of an oxidizing agent and the balance of deionized water, and the pH value is regulated to 7-11 by using a pH value regulator. The prepared polishing solution has the high material removal rate and the low surface roughness, the polishing efficiency is high, the polishing effect is good, the used dispersing agent, thickening agent and oxidizing agent are all green and environment-friendly materials and are biodegradable, and the risk that a traditional polishing solution pollutes the environment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of polishing liquids, and in particular relates to an environmentally friendly grinding and polishing liquid based on biodegradable materials and a preparation method thereof. Background Art

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

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

[0004] During storage, the polishing liquid still has problems such as poor dispersion and easy agglomeration, which leads to its poor stability and short life. It also results in low material removal rate of the workpiece and poor polishing effect. Therefore, further improvement is still needed.

[0005] In view of the problems existing in the prior art, how to provide a polishing liquid with high polishing efficiency, good treatment effect and environmental protection and no pollution is a problem to be solved urgently by the present invention. Summary of the Invention

[0006] The object of the present invention is to provide an environmentally friendly grinding and polishing liquid based on biodegradable materials and a preparation method thereof, so as to solve the problems raised in the above background technology.

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

[0008] The dispersant is modified hemicellulose;

[0009] The thickener is an anionic waterborne polyurethane;

[0010] The pH value of the environmentally friendly grinding and polishing liquid based on biodegradable materials is adjusted to 7-11 by a pH regulator.

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

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

[0013] (1) The corn stalks are naturally air-dried and then crushed, filtered through a 40-60 mesh filter, and the filtered raw material is added to an alkaline solution, stirred and mixed at 60-90° C., then cooled to room temperature, filtered, and a filtrate is obtained;

[0014] (2) adding an acidic solution dropwise to the filtrate, adjusting the pH to 5-6, centrifuging, collecting the liquid phase, rotary evaporating and concentrating, then transferring to a beaker, adding anhydrous ethanol, letting it stand for 2-5 hours, filtering, collecting the solid, rotary evaporating the filtrate again, adding anhydrous ethanol and letting it stand, collecting it again, and post-processing to obtain hemicellulose;

[0015] (3) Hemicellulose is added to an organic solvent, stirred and dissolved at 70-90°C, then cooled to 40-60°C, and a catalyst and maleic anhydride are added thereto. The reaction is continued for 2-5 hours. After the reaction is completed, post-processing is performed to obtain modified hemicellulose.

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

[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 of diamond, cubic boron nitride, silicon carbide, cerium oxide, silicon dioxide, and aluminum oxide.

[0020] In order to achieve better polishing effect, preferably, the abrasive is diamond abrasive.

[0021] As a further improvement, the average particle size of the abrasive is 50 nm-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 regulator is at least one of malic acid and potassium pyrophosphate.

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

[0025] The abrasive and deionized water are uniformly mixed according to weight, and then a dispersant, a thickener and an oxidant are added and continued to be stirred and mixed. The pH value is adjusted to 7-11 with a pH regulator to obtain an environmentally friendly grinding and polishing liquid based on biodegradable materials.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides an environmentally friendly grinding and polishing liquid based on biodegradable materials and a preparation method thereof, so that the prepared polishing liquid has a high material removal rate, indicating high polishing efficiency, and has low surface roughness, indicating that the surface of the processed workpiece is smooth and the polishing effect is good. In addition, the dispersant, thickener, and oxidant used are all green and environmentally friendly materials and are biodegradable, reducing the risk of traditional polishing liquid causing pollution to the environment. DETAILED DESCRIPTION

[0028] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0029] In the following examples, except for modified hemicellulose, the other compound monomers and related reagents used can be purchased from the market. Among them, the anionic water-based polyurethane was purchased from Green Union (Jining) Chemical Technology Co., Ltd., model 9190, the diamond abrasive was produced by the company, and the corn straw was sourced from rural fields in Zhengzhou, Henan; the cationic water-based polyurethane was purchased from Zibo Baowei New Material Technology Co., Ltd., model BW-8700.

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

[0031] (1) The corn stalks were naturally air-dried and then pulverized, filtered through a 50-mesh filter, and 20 g of the filtered raw material was added to 200 mL of a 60 g / L potassium hydroxide solution. The mixture was stirred at 80° C. for 2 h, then cooled to room temperature and filtered to obtain a filtrate.

[0032] (2) Acetic acid was added dropwise to the filtrate to adjust the pH to 5.5, centrifuged, and the liquid phase was collected. The liquid phase was then concentrated to 30 mL by rotary evaporation, and then transferred to a beaker. 100 mL of anhydrous ethanol was added thereto, and the mixture was allowed to stand for 3 h. The solid was collected by filtration, and the filtrate was rotary evaporated again. 100 mL of anhydrous ethanol was added and allowed to stand for a second time. The solid was then placed in a freeze dryer and dried for 12 h to obtain hemicellulose.

[0033] (3) 5 g of hemicellulose was dissolved in a mixture of 100 mL of N,N-dimethylformamide and 15 g of lithium chloride, stirred and dissolved at 85 °C, then cooled to 55 °C, and 1.5 g of bromosuccinimide and 20 g of maleic anhydride were added thereto. The reaction was continued for 3 h. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and vacuum dried for 24 h to obtain modified hemicellulose.

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

[0035] The abrasive and deionized water are uniformly mixed according to weight, and then a dispersant, a thickener and an oxidant are added and continued to be stirred and mixed. The pH value is adjusted to 10 with a pH regulator to obtain an environmentally friendly grinding and polishing liquid based on biodegradable materials.

[0036] The components and 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 liquid based on biodegradable materials prepared in Examples 1-3 and Comparative Examples 1-2 was tested for material removal rate and surface roughness performance. The test method is as follows:

[0041] Material Removal Rate: After weighing the sapphire wafer, adhere it to a ceramic disk with solid wax and place it in a polishing machine for polishing (test conditions: speed 80 r / min; pressure: 30 kg; time: 900 s; flow rate: 4 mL / min). After polishing, remove the sapphire wafer, clean it with ethanol and then water, let it dry naturally, and weigh it. The material removal rate is calculated according to the following formula:

[0042] MRR = (Δm) / ρtS;

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

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

[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] It can be seen from Example 2 and Comparative Example 1 in Table 2 that 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 likely to agglomerate and highly stable. In addition, the hemicellulose is derived from corn straw, is green, environmentally friendly, biodegradable, and does not cause environmental pollution.

[0049] It can be seen from Example 2 and Comparative Example 2 that compared with the polishing liquid prepared using cationic water-based polyurethane, the polishing liquid prepared using anionic water-based polyurethane has a higher material removal rate and lower surface roughness, indicating that the use of anionic water-based polyurethane as a thickener in the preparation of the polishing liquid can make the material have higher adhesion and improve the polishing efficiency. It is also in line with the concept of green environmental protection and will not cause pollution to the environment.

[0050] It can be seen from the test results of Examples 1-3 that the polishing liquid prepared by the preparation method provided by the present invention has a high material removal rate when used for workpiece processing, indicating high polishing efficiency, and has low surface roughness, indicating that the surface of the workpiece after processing is smooth and the polishing effect is good. In addition, the dispersant, thickener, and oxidant used are all green and environmentally friendly materials and are biodegradable, reducing the risk of traditional polishing liquids causing pollution to the environment.

[0051] The above embodiments are only for illustrating the technical concept and features of the present invention. Its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. It cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An environmentally friendly grinding and polishing liquid based on biodegradable materials, characterized in that: The polishing liquid comprises the following components in weight percentage: 0.5-2% abrasive, 1-5% dispersant, 0.5-2% thickener, 1-5% oxidant, and the balance is deionized water; The dispersant is modified hemicellulose; The thickener is an anionic waterborne polyurethane; The pH value of the environmentally friendly grinding and polishing liquid based on biodegradable materials is adjusted to 7-11 by a pH regulator.

2. The environmentally friendly grinding and polishing liquid based on biodegradable materials according to claim 1, characterized in that: The modified hemicellulose is prepared by reacting hemicellulose and maleic anhydride.

3. The environmentally friendly grinding and polishing liquid based on biodegradable materials according to claim 1, characterized in that: The synthesis of the modified hemicellulose comprises the following steps: (1) The corn stalks are naturally air-dried and then crushed, filtered through a 40-60 mesh filter, and the filtered raw material is added to an alkaline solution, stirred and mixed at 60-90° C., then cooled to room temperature, filtered, and a filtrate is obtained; (2) adding an acidic solution dropwise to the filtrate, adjusting the pH to 5-6, centrifuging, collecting the liquid phase, rotary evaporating and concentrating, then transferring to a beaker, adding anhydrous ethanol, letting it stand for 2-5 hours, filtering, collecting the solid, rotary evaporating the filtrate again, adding anhydrous ethanol and letting it stand, collecting it again, and post-processing to obtain hemicellulose; (3) Hemicellulose is added to an organic solvent, stirred and dissolved at 70-90°C, then cooled to 40-60°C, and a catalyst and maleic anhydride are added thereto. The reaction is continued for 2-5 hours. After the reaction is completed, post-processing is performed to obtain modified hemicellulose.

4. The environmentally friendly grinding and polishing liquid based on biodegradable materials according to claim 1, characterized in that: The pH value of the anionic waterborne polyurethane is 6-9.

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

6. The environmentally friendly grinding and polishing liquid based on biodegradable materials according to claim 1, characterized in that: The abrasive is at least one of diamond, cubic boron nitride, silicon carbide, cerium oxide, silicon dioxide and aluminum oxide.

7. The environmentally friendly grinding and polishing liquid based on biodegradable materials according to claim 1, characterized in that: The average particle size of the abrasive is 50 nm-50 μm.

8. The environmentally friendly grinding and polishing liquid 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.

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

10. The method for preparing an environmentally friendly grinding and polishing liquid based on biodegradable materials according to any one of claims 1 to 9, characterized in that: The following steps are involved: The abrasive and deionized water are uniformly mixed according to weight, and then a dispersant, a thickener and an oxidant are added and continued to be stirred and mixed. The pH value is adjusted to 7-11 with a pH regulator to obtain an environmentally friendly grinding and polishing liquid based on biodegradable materials.

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