CN105086836A - Cerium oxide polishing solution and preparation method thereof - Google Patents

Abstract

The invention discloses a cerium oxide polishing liquid. Its main components and dosage include: 0.1-0.3 parts of xanthan gum, 0.5-3 parts of sodium tripolyphosphate, 3-7 parts of sodium xylene sulfonate, 0.1-0.3 parts of EDTA-2Na, 3-7 parts of glycerin, poly Ethylene glycol 400? 2-5 parts, magnesium aluminum silicate 1-3 parts, thiourea 0.1-0.5 parts, triethanolamine 1-5 parts, cerium oxide polishing powder 50-60 parts, water 20-35 parts. The cerium oxide polishing liquid of the invention has high polishing speed, high polishing precision, reduced scratches and good suspension performance. The polishing solution of the present invention has better chemical and physical properties, and has been widely used in the polishing of industrial products. Polishing applications for precision products, etc.

Description

A kind of cerium oxide polishing liquid and preparation method thereof

technical field

The invention relates to a rare earth polishing liquid, which belongs to the field of grinding and polishing.

technical background

With the development of the rare earth industry, rare earth polishing powders soon succeeded in polishing precision optical instruments. Due to the advantages of high polishing efficiency, good quality, and low pollution, rare earth polishing powder has rapidly developed into the most popular precision polishing material on the market. In particular, cerium oxide polishing powder is the most superior. Due to the excellent chemical and physical properties of cerium-based rare earth polishing powder, it has been widely used in the polishing of industrial products, such as various optical glass devices, TV picture tubes, and optical glasses. Polishing of wafers, oscilloscope tubes, flat glass, semiconductor wafers and metal precision products. In order to endow the polishing powder with superior performance, the dispersion performance and suspension stability of the polishing powder in the liquid medium are very important influencing factors.

At present, most of the commercially available polishing liquids use titanium oxide, iron oxide, and silicon dioxide as abrasives, supplemented by other dispersing aids to obtain polishing liquids. This type of polishing liquid has low polishing precision and slow grinding speed, which is far from satisfying the existing production technology. need. There are also a few manufacturers who use rare earth cerium oxide as abrasive to make polishing fluid, but due to poor dispersion and suspension performance, ions are easy to agglomerate, resulting in scratches on the workpiece. The surface of the workpiece and the machine will cause the abrasive to sink to the bottom and agglomerate, reducing the efficiency of grinding and polishing. After polishing, there is a lot of polishing powder remaining on the surface of the workpiece, which is difficult to clean, which brings difficulties to the normal production in the later stage. It has failed to achieve standardization and serialization, and cannot fully meet the polishing requirements of various industrial fields. Therefore, it is of great significance to develop a cerium oxide polishing fluid with high grinding and polishing efficiency, less scratches, and good dispersion and suspension stability.

Contents of the invention

The purpose of the present invention is to overcome many disadvantages of the existing polishing liquid, and provide a cerium oxide polishing liquid with high grinding and polishing efficiency, less scratches and good dispersion and suspension stability.

In order to achieve the above object, the present invention adopts the following technical solutions:

A cerium oxide polishing solution, the main components and dosage of which include: 0.1-0.3 parts of xanthan gum, 0.5-3 parts of sodium tripolyphosphate, 3-7 parts of sodium xylene sulfonate, 0.1-0.3 parts of EDTA-2Na, Glycerin 3-7 parts, polyethylene glycol 4002-5 parts, magnesium aluminum silicate 1-3 parts, thiourea 0.1-0.5 parts, triethanolamine 1-5 parts, cerium oxide polishing powder 50-60 parts, water 20- 35 servings.

The present invention adopts cerium oxide as the polishing liquid abrasive material, and its main technical index is: w (REO)=90%, w (CeO2)=80%～85%; The recovery rate of rare earth is about 95%, and the average particle diameter is D501.2- 1.8μm, D902.6-2.8μm, D100≤3.2μm. The abrasive particle size distribution is reasonable, the polishing precision is high and the polishing speed is fast. The crystal form is intact, the wear resistance, fluidity and suspension are excellent, and it is suitable for high-speed polishing.

In order to realize the long-term suspension stability of the polishing liquid, the present invention adopts xanthan gum and magnesium aluminum silicate to cooperate to improve the suspension stability. Xanthan gum has a good suspending effect on insoluble solids. Xanthan gum sol molecules can form super-bonded ribbon-shaped helical copolymers, forming a fragile glue-like network structure, so they can support the shape of solid particles, showing strong stabilizing effect and high suspension capacity. Xanthan gum aqueous solution has high viscosity under static or low shearing action, and the viscosity drops sharply under high shearing action, but the molecular structure remains unchanged. And when the shear force is removed, the original viscosity will be restored immediately. The relationship between shear force and viscosity is completely plastic. The pseudoplasticity of xanthan gum is very prominent, and this pseudoplasticity is extremely effective for stabilizing suspensions. Magnesium aluminum silicate can expand into a colloidal dispersion in water, with a unique three-dimensional space chain structure and a special needle and rod crystal structure, so it has unusual colloidal and adsorption properties. With its excellent thickening, suspending, and colloid shake-melt properties. A "card palace"-like association network structure is formed in the water medium, so the combination of the two can greatly improve the suspension stability of the polishing solution and increase the dilution ratio of the polishing solution. Even if the original solution is diluted by more than 10 times, it can also Maintain a long suspension.

In the present invention, the abrasive is uniformly dispersed, the ions are not agglomerated, and the bottom is not agglomerated. Sodium tripolyphosphate and sodium xylene sulfonate are used as dispersants, which have good dispersing effect and almost no foam. It can make the polishing liquid dispersed and stable for a long time during use. There is no foam overflow in the circulating liquid supply of the machine, and the liquid supply system is stable.

The present invention adopts EDTA-2Na as the chelating agent in order to reduce the pollution of the metal iron filings on the machine platform to the system during the use of the polishing liquid. At the same time, thiourea is used as a corrosion inhibitor to reduce the corrosion of the machine and improve the stability of the entire polishing process.

The present invention adds glycerin, which has a certain protective effect on the parts directly contacted by operators. At the same time, the addition of glycerin makes the suspension agent xanthan gum disperse more uniformly, and further improves the suspension stability. The introduction of polyethylene glycol 400, used in conjunction with glycerin, plays a lubricating role in the grinding and polishing process, speeding up the polishing speed and precision. Polyethylene glycol 400 also has a certain cleaning effect, which is beneficial to the cleaning of the polishing powder after polishing .

The present invention uses triethanolamine as a synergist and a pH regulator, which can keep the system slightly alkaline for a long time. According to research, the slightly alkaline environment can increase the cutting force of the polishing powder and accelerate the polishing speed.

The preparation method of described polishing fluid, comprises the steps:

1) Dissolve and disperse xanthan gum with glycerin, then add polyethylene glycol 400 to continue stirring and dispersing for later use.

2) Dissolve sodium tripolyphosphate, sodium xylene sulfonate, EDTA-2Na, and thiourea with half the amount of water to obtain a solution for later use.

3) Use the other half of the amount of water to dissolve and disperse the magnesium aluminum silicate, and stir thoroughly to obtain a viscous colloid.

4) Mix all the materials in the above steps 1) 2) 3) evenly, and add cerium oxide to fully stir and disperse evenly.

5) Add triethanolamine to step 4) and continue stirring to obtain a uniform cerium oxide suspension polishing solution.

The present invention is a kind of cerium oxide polishing liquid, has following remarkable advantage compared with existing commercially available polishing liquid:

1. Excellent suspension and dispersion performance, long-term maintenance of uniform suspension state, no agglomeration of abrasives, no sedimentation and bottoming.

2. The polishing efficiency is high, the cutting force is strong, and the surface is less scratched. The conventional polishing machine can reduce the thickness by more than 3 μm in 10 minutes.

3. After polishing, the polishing liquid has little residue on the surface, and the polishing powder is easy to clean.

4. The service life is long and the dilution ratio is high. The polishing liquid can still maintain the original effect after being diluted more than 10 times with deionized water.

Detailed ways

Example 1

0.2 parts of xanthan gum, 2 parts of sodium tripolyphosphate, 5 parts of sodium xylene sulfonate, 0.2 parts of EDTA-2Na, 4 parts of glycerin, 4002 parts of polyethylene glycol, 2 parts of magnesium aluminum silicate, 0.3 parts of thiourea , 3 parts of triethanolamine, 55 parts of cerium oxide polishing powder, and 26.3 parts of water.

Example 2

0.1 part of xanthan gum, 3 parts of sodium tripolyphosphate, 4 parts of sodium xylene sulfonate, 0.1 part of EDTA-2Na, 3 parts of glycerin, 4003 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 0.1 part of thiourea , 2 parts of triethanolamine, 50 parts of cerium oxide polishing powder, and 33.2 parts of water.

Example 3

0.3 parts of xanthan gum, 1 part of sodium tripolyphosphate, 7 parts of sodium xylene sulfonate, 0.2 parts of EDTA-2Na, 7 parts of glycerin, 4002 parts of polyethylene glycol, 1 part of magnesium aluminum silicate, 0.2 parts of thiourea , 5 parts of triethanolamine, 51 parts of cerium oxide polishing powder, and 25.3 parts of water.

Example 4

0.2 parts of xanthan gum, 0.5 parts of sodium tripolyphosphate, 6 parts of sodium xylene sulfonate, 0.3 parts of EDTA-2Na, 4 parts of glycerin, 4003 parts of polyethylene glycol, 3 parts of magnesium aluminum silicate, 0.2 parts of thiourea , 3 parts of triethanolamine, 53 parts of cerium oxide polishing powder, and 26.8 parts of water.

Example 5

0.2 parts of xanthan gum, 3 parts of sodium tripolyphosphate, 3 parts of sodium xylene sulfonate, 0.2 parts of EDTA-2Na, 5 parts of glycerin, 4002 parts of polyethylene glycol, 1 part of magnesium aluminum silicate, 0.3 parts of thiourea , 5 parts of triethanolamine, 60 parts of cerium oxide polishing powder, and 20.3 parts of water.

The preparation method of above-mentioned embodiment:

1) Dissolve and disperse xanthan gum with glycerin, then add polyethylene glycol 400 to continue stirring and dispersing for later use.

2) Dissolve sodium tripolyphosphate, sodium xylene sulfonate, EDTA-2Na, and thiourea with half the amount of water to obtain a solution for later use.

3) Use the other half of the amount of water to dissolve and disperse the magnesium aluminum silicate, and stir thoroughly to obtain a viscous colloid.

4) Mix all the materials in the above steps 1) 2) 3) evenly, and add cerium oxide to fully stir and disperse evenly.

5) Add triethanolamine to step 4) and continue stirring to obtain a uniform cerium oxide suspension polishing solution.

The usage method of above-mentioned embodiment:

Measure 2 parts by volume of the cerium oxide polishing solution stock solution of the present invention with a measuring cup, dilute the cerium oxide polishing solution of the present invention with 8-15 parts by volume of deionized water, fully stir evenly, detect the specific gravity of the diluted solution with a hydrometer, and after reaching the approved index, add Use a circulation pump to circulate the liquid supply to the grinding and polishing machine. Use a hydrometer to monitor the concentration of the diluent. When the concentration drops to a certain index or the grinding and polishing efficiency is obviously reduced, add a small amount of stock solution to the liquid supply tank and continue to use it.

In order to verify the use effect of the present invention, the effect verification is carried out on the mobile phone cover glass on a double-sided grinding and polishing machine, and the results are as follows:

Note: Rating criteria for the stability of the stock solution (14 days of thermal storage in a thermostat at 54°C):

Grade A: Uniform and stable, no sedimentation and agglomeration at the bottom, and no water separation in the upper layer;

Grade B: Uniform and stable, no obvious precipitation at the bottom, slight water separation at the top;

Grade C: Relatively stable, slightly agglomerated at the bottom, and a small amount of water precipitates from the upper part, which can be re-dispersed evenly by shaking;

Grade D: Unstable, agglomerated at the bottom, abrasive and water layers, shaking can not restore the dispersion.

Working fluid stability rating standard (stand at room temperature for 24 hours):

Level 1: Uniform and stable, no obvious precipitation in the lower layer, no water separation in the upper layer, uniform suspension can be restored by slight shaking;

Level 2: relatively stable, with a small amount of precipitation in the lower layer, and slight water separation in the upper layer, and the uniform suspension can be restored by shaking;

Level 3: There is more precipitation in the lower layer, more water in the upper layer, the suspension can be partially restored by shaking, and there are agglomerates at the bottom that are difficult to disperse and suspend;

Grade 4: Severe stratification, severe caking at the bottom, shaking cannot restore suspension.

Thinning thickness is detected by electronic thickness gauge.

The surface scratch detection is measured by an automatic detector for glass defects (scratches) on the touch LCD screen.

The ease of cleaning after polishing is tested on the automatic cleaning line to evaluate the polishing powder residue, the difficulty of removing glass shavings, and the surface cleanliness.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (3)

1. a cerium oxide polishing slurry, is characterized in that, its bulk composition and consumption comprise: xanthan gum 0.1-0.3 part, tripoly phosphate sodium STPP 0.5-3 part, sodium xylene sulfonate 3-7 part, EDTA-2Na0.1-0.3 part, glycerine 3-7 part, poly(oxyethylene glycol) 400 2-5 part, neusilin 1-3 part, thiocarbamide 0.1-0.5 part, trolamine 1-5 part, cerium rouge 50-60 part, water 20-35 part.

2. cerium oxide polishing slurry according to claim 1, is characterized in that, the weight part of each raw material is xanthan gum 0.2 part, tripoly phosphate sodium STPP 2 parts, sodium xylene sulfonate 5 parts, EDTA-2Na0.2 part, glycerine 4 parts, poly(oxyethylene glycol) 400 2 parts, neusilin 2 parts, thiocarbamide 0.3 part, trolamine 3 parts, cerium rouge 55 parts, 26.3 parts, water.

3. a preparation method for cerium oxide polishing slurry, is characterized in that:

1) by xanthan gum with glycerine dissolve dispersion, then add poly(oxyethylene glycol) 400 continue dispersed with stirring for subsequent use;

2)dissolve tripoly phosphate sodium STPP with half water gaging, sodium xylene sulfonate, EDTA-2Na, thiocarbamide, obtains solution for standby;

3)dissolve disperse silicic acid magnalium with second half water gaging, fully stir and obtain thick gel;

4)by above-mentioned steps 1) 2) 3) and in all materials mix, and it is even to add the abundant dispersed with stirring of cerium oxide;

5)to step 4) in add trolamine continue stir, obtain homogeneous cerium oxide suspension polishing liquid.