Modified rare earth polishing powder as well as preparation method and application thereof

Abstract

The invention provides modified rare earth polishing powder as well as a preparation method and application thereof. The modified rare earth polishing powder comprises rare earth polishing powder and modified groups chemically bonded to the surface of the rare earth polishing powder, the modified groups comprise A-type groups and B-type groups, and the A-type groups are phosphorus-containing groups; the B group is a carboxyl group with a long-chain structure and is generated through a bonding reaction between one or more of carboxymethyl cellulose and sodium salt thereof, an acrylic polymer and a derivative thereof and the rare earth polishing powder. In the modified rare earth polishing powder disclosed by the invention, the surface of the rare earth polishing powder contains two types of modified groups A and B, and the modified groups A and B have relatively strong interaction with the surface of the rare earth polishing powder and can synergistically inhibit particle aggregation of the rare earth polishing powder, so that the suspension stability and redispersibility of the modified rare earth polishing powder are greatly improved; high polishing efficiency and high polishing precision can be well considered, and the requirements of precision polishing fields of precision optical glass, liquid crystal display glass substrates, integrated circuits and the like are met.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth polishing materials, and in particular to a modified rare earth polishing powder, a preparation method and application thereof. Background Art

[0002] Chemical mechanical polishing (CMP) is an ultra-precision polishing process that effectively achieves global flattening of workpieces at the nanoscale. It is indispensable in the manufacture of mobile phone cover glass, precision optical glass, liquid crystal display glass substrates, and integrated circuits. The essence of the CMP process is the chemical corrosion and mechanical wear of the material surface by the effective components in the polishing liquid. Therefore, if you want to achieve better polishing accuracy at a higher polishing rate, you must balance the chemical corrosion and mechanical wear of the polishing liquid on the workpiece being polished.

[0003] As an important component of polishing liquid, the physical and chemical properties of polishing powder directly affect the quality and precision of surface polishing, and it is the decisive factor for the surface quality after polishing. Rare earth polishing powder with cerium oxide as the main body has excellent chemical mechanical polishing performance. On the one hand, its uniform particle size and moderate hardness (Mohs hardness is close to glass hardness) can ensure a certain mechanical grinding force while reducing the mechanical damage to the surface quality of the sample. On the other hand, the multivalent state of Ce and its easy conversion characteristics make nano cerium oxide have a strong chemical effect on silicon-based materials. In coordination with mechanical action, high-efficiency and high-precision chemical mechanical polishing is achieved.

[0004] However, rare earth polishing powder has high surface energy and is easy to agglomerate, which affects the polishing quality and precision. Therefore, improving its dispersion effect in water and obtaining a polishing liquid with good suspension stability is crucial for the application of rare earth polishing powder in the field of ultra-precision polishing. Adding surfactants when preparing polishing liquid is a conventional method to improve the suspension stability of rare earth polishing powder. By changing the steric hindrance and electrostatic repulsion between particles, the tendency of rare earth polishing powder particles to agglomerate and the sedimentation rate are reduced, and the polishing precision is ultimately improved. However, when using the above method, the surfactant and the rare earth polishing powder are mainly weakly physically adsorbed, resulting in an unstable surface state of the polishing powder particles, which is prone to flocculation, solidification and other problems during recycling, thereby affecting the polishing precision and consistency.

[0005] With the rapid development of electronic information industry technology, the requirements for rare earth polishing fluids in the field of precision polishing are becoming increasingly higher. It is necessary to achieve high polishing accuracy while achieving high polishing rates. Therefore, it is urgent to further optimize the surface stability of rare earth polishing powders and improve the suspension stability of rare earth polishing fluids to obtain highly dispersed, highly efficient, and highly precise rare earth polishing fluids to meet the ever-evolving downstream application requirements. Summary of the invention

[0006] The main purpose of the present invention is to provide a modified rare earth polishing powder, a preparation method and application thereof, so as to solve the problem that the rare earth polishing powder in the prior art has poor suspension stability and redispersibility, resulting in poor polishing efficiency and polishing accuracy.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a modified rare earth polishing powder is provided, comprising rare earth polishing powder and a modified group bonded to its surface, the modified group comprising a Class A group and a Class B group, wherein the Class A group is a phosphorus-containing group; and the Class B group is a carboxyl group having a long-chain structure.

[0008] Further, the modified rare earth polishing powder contains P element and C element, and the P element content in the modified rare earth polishing powder is 0.01-3%, and the C element content is 0.01-5% by weight; preferably, the P element content in the modified rare earth polishing powder is 0.05-3%, and the C element content is 0.01-1%; and / or the A-type group is generated by a bonding reaction between a phosphorus-containing group precursor and the rare earth polishing powder; the phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and sodium salts, potassium salts and One or more ammonium salts; preferably, the organic phosphorus-containing group precursor includes one or more phosphates and their derivatives; and / or the B group is produced by the bonding reaction of a long-chain carboxyl precursor and a rare earth polishing powder; preferably, the long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and its sodium salt, alginate and its sodium salt, acrylic acid polymer and its derivatives; more preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate.

[0009] Furthermore, the chemical formula of the rare earth polishing powder is Ce 1-x M x O y N z , wherein M includes one or more of rare earth elements except cerium, transition metal elements, alkaline earth metal elements, alkali metal elements, aluminum, tin, silicon, boron and arsenic, and N includes one or more of F, Cl and S; 0≤x≤0.6, 1.0<y≤2.0, 0≤z≤0.9; preferably, M includes one or more of lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, ytterbium, yttrium, titanium, zirconium, iron, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; more preferably, M includes one or more of lanthanum, praseodymium, neodymium, samarium, ytterbium, yttrium, titanium, zirconium, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; preferably, 0≤x≤0.4, 1.2≤y≤2.0, 0≤z≤0.65.

[0010] Furthermore, the D of the modified rare earth polishing powder 50 It is 0.01 to 5.0 μm, preferably 0.01 to 2.0 μm, and more preferably 0.1 to 1.5 μm.

[0011] According to another aspect of the present invention, a method for preparing the modified rare earth polishing powder of the present invention is provided, wherein the rare earth polishing powder is mixed with a phosphorus-containing group precursor and a long-chain carboxyl precursor, and reacted under heat treatment conditions to obtain the modified rare earth polishing powder; wherein the phosphorus-containing group precursor is used to chemically bond Class A groups on the surface of the rare earth polishing powder, and the long-chain carboxyl precursor is used to chemically bond Class B groups on the surface of the rare earth polishing powder.

[0012] Further, the phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and sodium salts, potassium salts and ammonium salts of the above substances; preferably, the organic phosphorus-containing group precursor includes one or more of phosphate esters and derivatives thereof; and / or the long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and sodium salts thereof, alginate and sodium salts thereof, acrylic acid polymers and derivatives thereof; preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate.

[0013] Furthermore, the weight ratio of rare earth polishing powder to phosphorus-containing group precursor and long-chain carboxyl precursor is 100:(0.1-20):(0.1-10), preferably 100:(0.5-20):(0.25-8); and / or the mixing is wet mixing or dry mixing; preferably, during the wet mixing process, the pH of the system is controlled to be 6.0-9.0; and / or the heat treatment temperature is 50-300°C, the time is 0.5-48h, and the heating rate is 1-10°C / min; preferably, the heat treatment temperature is 100-250°C.

[0014] Further, the mixing includes the following methods: method 1, mixing the rare earth polishing powder with a phosphorus-containing group precursor, and performing a first heat treatment to obtain a first product; then mixing the first product with a long-chain carboxyl precursor, and performing a second heat treatment to obtain a modified rare earth polishing powder; or method 2, mixing the rare earth polishing powder with a long-chain carboxyl precursor, and performing a third heat treatment to obtain a second product; then mixing the second product with a phosphorus-containing group precursor, and performing a fourth heat treatment to obtain a modified rare earth polishing powder; or method 3, mixing the rare earth polishing powder with a phosphorus-containing group precursor and a long-chain carboxyl precursor at the same time, and performing a heat treatment to obtain a modified rare earth polishing powder; wherein the temperatures of the first heat treatment, the second heat treatment, the third heat treatment and the fourth heat treatment are independently 50 to 300°C, the times are independently 0.5 to 48h, and the heating rates are independently 1 to 10°C / min.

[0015] According to another aspect of the present invention, a rare earth polishing liquid is provided, comprising the modified rare earth polishing powder of the present invention, a surfactant, a pH regulator and water; preferably, by weight percentage, the rare earth polishing liquid comprises 1 to 20% of the modified rare earth polishing powder; more preferably 5 to 10%; preferably, by weight percentage, the rare earth polishing liquid comprises 0 to 5% of a surfactant, and the surfactant comprises one or more of aminotrimethylphosphonic acid, sodium aminotrimethylphosphonic acid, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, sodium dodecyl sulfonate, polyethylene glycol, polyvinyl alcohol and polymethacrylate; preferably, the rare earth polishing liquid also comprises an inorganic phosphorus-containing group precursor, and the weight ratio of the modified rare earth polishing powder to the inorganic phosphorus-containing group precursor is 100:(0.5 to 5), and the inorganic phosphorus-containing group precursor comprises one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and the sodium salts, potassium salts and ammonium salts of the above substances.

[0016] According to another aspect of the present invention, there is provided the use of the modified rare earth polishing powder and / or rare earth polishing liquid in the fields of flat glass, mobile phone cover glass, optical glass, liquid crystal display glass, glass substrate and integrated circuit.

[0017] In the modified rare earth polishing powder of the present invention, the surface of the rare earth polishing powder contains two types of modified groups, A and B, which have a strong interaction with the surface of the rare earth polishing powder, can synergistically inhibit the agglomeration of rare earth polishing powder particles, and form a flexible barrier layer on the surface of the particles to avoid solidification and caking, enhance the surface stability of rare earth polishing powder particles, improve its suspension stability and redispersibility when used in rare earth polishing liquid, and increase the number of effective particles in the chemical mechanical polishing process, thereby well improving the contact condition between the polishing material and the polished workpiece, while maintaining a high polishing rate. Reduce polishing damage and improve polishing accuracy. At the same time, the rare earth polishing liquid containing this modified rare earth polishing powder has good suspension stability, a high polishing rate and extremely low polishing damage. After multiple high-speed centrifugal washings or recycling, it still has good redispersibility and suspension stability, and the polishing consistency is greatly improved. In summary, the suspension stability and redispersibility of the modified rare earth polishing powder of the present invention are greatly improved, and it can well take into account high polishing efficiency and high polishing accuracy, and meet the needs of precision optical glass, liquid crystal display glass substrates, integrated circuits and other precision polishing fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 The photographs showing the dispersion of the modified rare earth polishing liquid according to Examples 1 to 7 of the present invention after being left to stand for 24 hours;

[0020] Figure 2 shows the Fourier transform infrared spectra of the rare earth polishing powder before and after modification according to Example 1 of the present invention; and

[0021] Figure 3 The X-ray photoelectron spectra of the rare earth polishing powder before and after modification according to Example 6 of the present invention are shown.

[0022] The above drawings include the following reference numerals:

[0023] 1. Example 1; 2. Example 2; 3. Example 3; 4. Example 4; 5. Example 5; 6. Example 6; 7. Example 7; a. After modification of the rare earth polishing powder of Example 1; b. Before modification of the rare earth polishing powder of Example 1; c. After modification of the rare earth polishing powder of Example 6; d. Before modification of the rare earth polishing powder of Example 6. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] As described in the background of the present invention, there is a problem in the prior art that rare earth polishing powder cannot take into account dispersion stability, high polishing efficiency and high polishing precision. In order to solve the above problem, in a typical embodiment of the present invention, a modified rare earth polishing powder is provided, including rare earth polishing powder and a modified group bonded to the surface thereof, the modified group including a class A group and a class B group, wherein the class A group is a phosphorus-containing group; and the class B group is a carboxyl group with a long chain structure.

[0026] In the modified rare earth polishing powder of the present invention, the surface of the rare earth polishing powder particles contains at least two types of modified groups, A and B, wherein the A type group makes the rare earth polishing powder particles carry a large amount of negative charge, and the carboxyl group with a long chain structure separates the rare earth polishing powder particles adsorbed with the A type group from each other to form a steric barrier layer, blocking the bridging between the molecules of the A type group, thereby improving the suspension stability and redispersibility of the rare earth polishing powder particles. It has a strong interaction with the surface of the rare earth polishing powder, such as hydrogen bonding, van der Waals force or covalent bond interaction, which can synergistically inhibit the agglomeration of particles in the rare earth polishing powder, and form a flexible barrier layer on the surface of the particles to avoid solidification and hardening. The strong interaction between the modified group and the surface of the rare earth polishing powder ensures the surface stability of the rare earth polishing powder particles, can improve its suspension stability and redispersibility when used in rare earth polishing liquid, and increase the number of effective particles in the chemical mechanical polishing process, thereby well improving the contact condition between the polishing material and the polished workpiece, and reducing polishing damage while maintaining a high polishing rate.

[0027] The rare earth polishing liquid containing this modified rare earth polishing powder also has good suspension stability, high polishing rate and extremely low polishing damage. After multiple high-speed centrifugal washing or recycling, it still has good redispersibility and suspension stability, and the polishing consistency is greatly improved. Among them, the rare earth polishing powder can use conventional types in the field, such as CeO2, etc. It is understood that the surface of the rare earth polishing powder has groups such as hydroxyl groups. These are understandable to those skilled in the art and will not be repeated here.

[0028] It should be noted that the specific structures of the A-type group and the B-type group chemically bonded to the surface of the rare earth polishing powder in the modified rare earth polishing powder can be determined by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Figure 2 As shown in the Fourier transform infrared spectrum of the modified rare earth polishing powder, the -1 (POP absorption vibration peak), 910~990cm -1 (PO absorption vibration peak), 1100~1200cm -1There is a peak at the position of (absorption vibration peak of P=O), from which it is inferred that the surface of the modified rare earth polishing powder has phosphorus-containing groups such as POP, PO, and P=O; at the same time, at 1530~1650cm -1 (-COOH stretching vibration peak) position, it is inferred that the surface of the modified rare earth polishing powder has a long-chain carboxyl group. In one embodiment of the present invention, Figure 3 As shown, in the X-ray photoelectron spectrum of the modified rare earth polishing powder, there is a peak at about 130 eV (P position), from which it is inferred that the surface of the modified rare earth polishing powder has phosphorus-containing groups.

[0029] In order to further improve the effect of the modified groups in synergistically inhibiting the agglomeration of particles in the rare earth polishing powder, in a preferred embodiment, the modified rare earth polishing powder contains P and C elements, and the P content of the modified rare earth polishing powder is 0.01-3%, and the C content is 0.01-5% by weight; preferably, the P content of the modified rare earth polishing powder is 0.05-3%, and the C content is 0.01-1%. The above weight percentages of P and C can reduce preparation redundancy and reduce preparation and use costs while further ensuring that the surface stability of the rare earth polishing powder particles is improved.

[0030] And / or the A-type group is generated by the bonding reaction of a phosphorus-containing group precursor with a rare earth polishing powder; the phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and sodium salts, potassium salts and ammonium salts of the above substances; preferably, the organic phosphorus-containing group precursor includes one or more of phosphate esters and their derivatives; and / or the B-type group is generated by the bonding reaction of a long-chain carboxyl precursor with a rare earth polishing powder; preferably, the long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and its sodium salt, alginate and its sodium salt, acrylic acid polymer and its derivatives; more preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate. The above-mentioned phosphorus-containing group precursor and long-chain carboxyl precursor can better chemically bond to the A-type group and the B-type group on their surface for modification, thereby better synergistically improving their suspension stability and redispersibility, avoiding the problem of long-term static solidification and hardening, and having better polishing performance.

[0031] In a preferred embodiment, the chemical formula of the rare earth polishing powder is Ce 1-x M x O y N z, wherein M includes one or more of rare earth elements except cerium, transition metal elements, alkaline earth metal elements, alkali metal elements, aluminum, tin, silicon, boron and arsenic, and N includes one or more of F, Cl and S; 0≤x≤0.6, 1.0<y≤2.0, 0≤z≤0.9; there is a stronger interaction between the above-mentioned rare earth polishing powder and the A-type group and the B-type group, which can further prevent the agglomeration of rare earth polishing powder particles while improving the suspension stability in the dispersed system, improve its redispersibility, and make the number of effective particles in the polishing process larger, thereby achieving high polishing efficiency and high polishing accuracy.

[0032] In order to further optimize the chemical activity of rare earth polishing materials, improve the morphology, size, crystal structure and phase composition of rare earth polishing powder, improve the suspension stability of powder, give full play to the dual synergy of chemical and physical effects of rare earth polishing materials during polishing, and achieve high-speed and high-quality polishing, preferably, M includes one or more of lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, ytterbium, yttrium, titanium, zirconium, iron, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; more preferably, M includes one or more of lanthanum, praseodymium, neodymium, samarium, ytterbium, yttrium, titanium, zirconium, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; preferably, 0≤x≤0.4, 1.2≤y≤2.0, 0≤z≤0.65.

[0033] In a preferred embodiment, the D of the modified rare earth polishing powder 50 The modified rare earth polishing powder has a secondary particle size D50 of 0.01 to 5.0 μm, preferably 0.01 to 2.0 μm, and more preferably 0.1 to 1.5 μm. Thus, the suspension stability of the modified rare earth polishing powder can be further improved. The secondary particle size D50 of the modified rare earth polishing powder is measured after the modified rare earth polishing powder is properly dispersed in water. These are understandable to those skilled in the art and will not be described in detail here.

[0034] In another typical embodiment of the present invention, a method for preparing the modified rare earth polishing powder of the present invention is also provided, wherein the rare earth polishing powder is mixed with a phosphorus-containing group precursor and a long-chain carboxyl precursor, and the mixture is reacted under heat treatment conditions to obtain a modified rare earth polishing powder; wherein the phosphorus-containing group precursor is used to chemically bond a type A group to the surface of the rare earth polishing powder, and the long-chain carboxyl precursor is used to chemically bond a type B group to the surface of the rare earth polishing powder.

[0035] Under the action of steric hindrance and electrostatic stabilization, the rare earth polishing powder reacts with the phosphorus-containing group precursor raw material to generate type A groups, so that the groups with P elements are adsorbed and chemically bonded on the surface of the rare earth polishing powder to form phosphorus-containing groups; by reacting with the long-chain carboxyl precursor raw material to generate type B groups, the carboxyl groups with long-chain structures are grafted on the surface of the particles to form a flexible barrier layer to prevent the particles from agglomerating. The above preparation method is simple, easy to operate, and has a low preparation cost. The prepared modified rare earth polishing powder has good suspension stability and redispersibility, and can well balance high polishing efficiency and high polishing accuracy, meeting the needs of precision polishing fields such as precision optical glass, liquid crystal display glass substrates, and integrated circuits.

[0036] In a preferred embodiment, the phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and sodium salts, potassium salts and ammonium salts of the above substances; preferably, the organic phosphorus-containing group precursor includes one or more of phosphate esters and derivatives thereof; and / or the long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and sodium salts thereof, alginate and sodium salts thereof, acrylic acid polymers and derivatives thereof; preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate. The above-mentioned phosphorus-containing group precursor and long-chain carboxyl precursor have a stronger binding effect with the rare earth polishing powder, and can better chemically bond with the A-type group and the B-type group on its surface for modification, thereby better synergistically improving its suspension stability and redispersibility, avoiding the problem of long-term static solidification and hardening, and having better polishing performance. At the same time, the above-mentioned two types of raw materials will not react with each other to cause an increase in impurities in the product, affecting the performance of the modified rare earth polishing powder.

[0037] Taking the phosphorus-containing group precursor as sodium hexametaphosphate and the long-chain carboxyl precursor as sodium carboxymethyl cellulose as an example, the preparation process of the modified rare earth polishing powder of the present invention is derived as follows: in the preparation system, the long-chain metaphosphate group in the isoelectric point state replaces part of the hydroxyl group and adsorbs on the surface of the rare earth polishing powder particles, so that the rare earth polishing powder particles carry a large amount of negative charge; the sodium carboxymethyl cellulose with a molecular weight much larger than that of sodium hexametaphosphate is ionized in the system, and forms hydrogen bonds with the hydroxyl active sites on the surface of the rare earth polishing powder, generating carboxyl groups with a long-chain structure, and its long-chain structure separates the rare earth polishing powder particles adsorbed with sodium hexametaphosphate from each other, forming a steric hindrance layer, blocking the bridging between sodium hexametaphosphate molecules, and improving the suspension stability and redispersibility of the rare earth polishing powder particles through the dual effects of steric hindrance and electrostatic stabilization. It should be noted that there is no requirement for the order of adding sodium hexametaphosphate and sodium carboxymethyl cellulose, as long as the two modified raw materials and the rare earth polishing powder are in the same system, the above-mentioned effects can be performed.

[0038] In a preferred embodiment, the weight ratio of the rare earth polishing powder to the phosphorus-containing group precursor and the long-chain carboxyl precursor is 100:(0.1-20):(0.1-10), preferably 100:(0.5-20):(0.25-8), so that the A-type group and the B-type group can be more fully and effectively chemically bonded to the surface of the rare earth polishing powder particles, further improving the suspension stability and redispersibility of the modified rare earth polishing powder, increasing the number of effective particles in the polishing process, and further improving the polishing efficiency while ensuring the polishing accuracy; and / or the mixing is wet mixing or dry mixing; preferably, during the wet mixing process, the pH of the system is controlled to be 6.0-9.0; within this pH range, the surface of the rare earth polishing powder is formed by rare earth element-OH, rare earth element-OH 2+ It is mainly positive potential, which is more conducive to the reaction between the raw materials producing A and B groups and the surface of rare earth polishing powder particles.

[0039] The inventor unexpectedly found during the research that if the heat treatment intensity is too low, it is not conducive to the chemical reaction between the long-chain carboxyl precursor and the surface of the rare earth polishing powder, resulting in a small amount of grafting of the class B group and an inability to fully form a flexible barrier layer; if the heat treatment intensity is too high, the phosphorus-containing group precursor or the long-chain carboxyl precursor will decompose or react with side effects, and the synergistic effect of different raw materials cannot be effectively exerted, affecting the modified rare earth polishing powder or the polishing slurry dispersibility and polishing application performance thereof. Therefore, in a preferred embodiment, the heat treatment temperature is 50 to 300°C, the time is 0.5 to 48h, and the heating rate is 1 to 10°C / min; preferably, the heat treatment temperature is 100 to 250°C.

[0040] The type A groups and type B groups in the modified rare earth polishing powder of the present invention will not react or affect each other, so the phosphorus-containing group precursor and the long-chain carboxyl precursor in the preparation method can be added step by step or simultaneously, and there is no fixed order for addition. In a preferred embodiment, the mixing includes the following methods: method 1, mixing the rare earth polishing powder with a phosphorus-containing group precursor, and performing a first heat treatment to obtain a first product; then mixing the first product with a long-chain carboxyl precursor, and performing a second heat treatment to obtain a modified rare earth polishing powder; or method 2, mixing the rare earth polishing powder with a long-chain carboxyl precursor, and performing a third heat treatment to obtain a second product; then mixing the second product with a phosphorus-containing group precursor, and performing a fourth heat treatment to obtain a modified rare earth polishing powder; or method 3, mixing the rare earth polishing powder with a phosphorus-containing group precursor and a long-chain carboxyl precursor at the same time, and performing a heat treatment to obtain a modified rare earth polishing powder; wherein the temperatures of the first heat treatment, the second heat treatment, the third heat treatment and the fourth heat treatment are independently 50 to 300°C, the times are independently 0.5 to 48h, and the heating rates are independently 1 to 10°C / min.

[0041] In another typical embodiment of the present invention, a rare earth polishing liquid is provided, comprising the modified rare earth polishing powder of the present invention, a surfactant, a pH regulator and water; due to the use of the modified rare earth polishing powder of the present invention, it has good suspension stability, a high polishing rate and extremely low polishing damage, and after multiple high-speed centrifugal washings or recycled use, it still has good redispersibility and suspension stability.

[0042] Preferably, by weight percentage, the rare earth polishing liquid includes 1-20% of modified rare earth polishing powder; more preferably 5-10%; preferably, by weight percentage, the rare earth polishing liquid includes 0-5% of surfactant, and the surfactant includes one or more of aminotrimethylphosphonic acid, aminotrimethylphosphonic acid sodium salt, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, sodium dodecyl sulfonate, polyethylene glycol, polyvinyl alcohol and polymethacrylate; preferably, by weight percentage, the rare earth polishing liquid includes 0-5% of surfactant; the surfactant can be conventional types in the art, more preferably 0-1%; preferably, the rare earth polishing liquid also includes an inorganic phosphorus-containing group precursor, the weight ratio of the modified rare earth polishing powder to the inorganic phosphorus-containing group precursor is 100: (0.5-5), and the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and the sodium salt, potassium salt and ammonium salt of the above substances. Under the above conditions, the suspension stability and polishing performance of the rare earth polishing liquid are better.

[0043] In another typical embodiment of the present invention, the modified rare earth polishing powder and / or rare earth polishing liquid of the present invention is also provided for use in the fields of flat glass, mobile phone cover glass, optical glass, liquid crystal display glass, glass substrate and integrated circuits, which can take into account both a higher polishing rate and extremely low polishing damage, and meet the precision polishing requirements in the above-mentioned fields.

[0044] Typically, but not limiting, in the modified rare earth polishing powder, the P element content is 0.01%, 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3% or any two of them; C content is 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.08% , 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1 %, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5% or a range consisting of any two of them.

[0045] Typically, but not exclusively, the chemical formula of rare earth polishing powder is Ce 1-x M x O y N z , wherein x is 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or a range consisting of any two of them; y is 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 or a range consisting of any two of them; z is 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7, 0.8, 0.9 or a range consisting of any two of them.

[0046] Typical but non-limiting properties of modified rare earth polishing powders are 50It is 0.01μm, 0.1μm, 0.2μm, 0.3μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 1.0μm, 1.2μm, 1.5μm, 1.8μm, 2.0μm, 2.2μm, 2.5μm, 2.8μm, 3.0μm, 3.2μm, 3.5μm, 3.8μm, 4.0μm, 4.2μm, 4.5μm, 4.8μm, 5.0μm or a range consisting of any two of them.

[0047] Typically but not limiting, in the preparation method of the modified rare earth polishing powder, when the weight of the rare earth polishing powder is 100 (i.e., the weight ratio of the rare earth polishing powder to the phosphorus-containing group precursor and the long-chain carboxyl precursor, based on the weight of the rare earth polishing powder as 100), the weight of the phosphorus-containing group precursor is 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or a range consisting of any two of them; the weight of the long-chain carboxyl precursor is 0.1, 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or a range consisting of any two of them.

[0048] Typically, but not limiting, in the preparation method of the modified rare earth polishing powder, the heat treatment temperature is 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C or a range of any two of them; the time is 0.5h, 1h, 2h, 4h, 6h The temperature is preferably 0.1°C / min, 0.2°C / min, 0.3°C / min, 0.4°C / min, 0.5°C / min, 0.6°C / min, 0.7°C / min, 0.8°C / min, 0.9°C / min, 10.1°C / min, or a range consisting of any two of them. The temperature rise rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, or a range consisting of any two of them.

[0049] Typically but not limiting, the rare earth polishing solution comprises, by weight percentage, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% or a range consisting of any two of them of modified rare earth polishing powder.

[0050] Typically but not limiting, when the rare earth polishing liquid also includes an inorganic phosphorus-containing group precursor, the weight ratio of the modified rare earth polishing powder to the inorganic phosphorus-containing group precursor is 100:0.5, 100:1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5, 100:4, 100:4.5, 100:5 or a range value consisting of any two ratios thereof.

[0051] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0052] Example 1

[0053] Wet mixing first A and then B: weigh 15.00g of rare earth polishing powder into a beaker, add 0.75g of sodium hexametaphosphate solution (10wt.%), add deionized water to the beaker to a total weight of 20.00g, and stir to disperse for 1h; heat treat at 50°C for 0.5h (heating rate 2°C / min); then add 0.75g of carboxymethyl cellulose solution (10wt.%), add deionized water to the beaker to a total weight of 30.00g, and stir evenly; heat treat at 100°C for 15h (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0054] Example 2

[0055] Dry mix A first and then B: weigh 50.00g of rare earth polishing powder into a high-speed mixer, add 2.00g of metaphosphoric acid, and mix at high speed for 10min; heat treat at 50°C for 2h (heating rate 5°C / min); then add 0.25g of sodium carboxymethyl cellulose and mix using a high-speed mixer for 10min; heat treat at 60°C for 48h (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0056] Example 3

[0057] Wet simultaneous mixing: weigh 15.00 g of rare earth polishing powder into a ball mill, add 1.5 g of tripolyphosphoric acid solution (10 wt.%) and 0.9375 g of maleic acid-acrylic acid copolymer sodium salt solution (40 wt.%), and ball mill for 30 min; heat treat at 120°C for 6 h (heating rate 3°C / min) to obtain modified rare earth polishing powder.

[0058] Example 4

[0059] Dry mix B first and then A: weigh 50.00g of rare earth polishing powder into a high-speed mixer, add 2.00g of potassium polyacrylate, and mix using a high-speed mixer for 20min; heat treat at 50°C for 1h (heating rate 1°C / min); then add 0.25g of sodium pyrophosphate and mix for 20min; heat treat at 100°C for 8h (heating rate 1°C / min) to obtain modified rare earth polishing powder.

[0060] Example 5

[0061] Dry mix B then A: weigh 50.00g of rare earth polishing powder in a high-speed mixer, add 0.50g of polyacrylic acid and 0.25g of carboxymethyl cellulose, and mix for 20min; heat treat at 100℃ for 2h (heating rate 5℃ / min); then add 3.00g of pyrophosphoric acid and mix for 20min; heat treat at 150℃ for 3h (heating rate 3℃ / min) to obtain modified rare earth polishing powder.

[0062] Example 6

[0063] Wet mixing first A and then B: weigh 15.00g of rare earth polishing powder into a beaker, add 7.50g of sodium hexametaphosphate solution (10wt.%), add deionized water to the beaker to a total weight of 20.00g, and heat treat at 60°C for 1h (heating rate 2°C / min); then add 0.75g of maleic acid acrylic acid copolymer and sodium carboxymethyl cellulose solution (10wt.%) respectively, and then add deionized water to a total weight of 30.00g, stirring for 1h; and heat treat at 250°C for 2h (heating rate 3°C / min) to obtain modified rare earth polishing powder.

[0064] Example 7

[0065] Dry mix A and then B: weigh 50.00g of rare earth polishing powder into a high-speed mixer, add 5.00g of potassium pyrophosphate; heat treat at 50°C for 3h (heating rate 3°C / min); then add 0.50g of sodium polymethacrylate and mix using a high-speed mixer for 20min; heat treat at 70°C for 20h (heating rate 10°C / min) to obtain modified rare earth polishing powder.

[0066] Example 8

[0067] Dry mix B then A: weigh 15.00g of rare earth polishing powder into a beaker, add 0.60g of sodium alginate, mix with a high-speed mixer for 1h; heat treat at 70℃ for 2h (heating rate 3℃ / min); then add 1.20g of sodium hexametaphosphate, mix with a high-speed mixer for 1h; heat treat at 90℃ for 5h (heating rate 2℃ / min) to obtain modified rare earth polishing powder.

[0068] Example 9

[0069] Wet mixing: first B and then A: weigh 15.00g of rare earth polishing powder into a beaker, add 1.20g of alginate, add deionized water to the beaker to a total weight of 20.00g, and stir for 1h; heat treat at 90°C for 3h (heating rate 5°C / min); then add 1.35g of sodium hexametaphosphate, add deionized water to a total weight of 30.00g, and stir evenly; hydrothermally treat at 80°C for 3h (heating rate 5°C / min), centrifuge and dry to obtain modified rare earth polishing powder.

[0070] Example 10

[0071] Dry mix A and then B: weigh 50.00g of rare earth polishing powder into a high-speed mixer, add 0.75g of pyrophosphoric acid, and mix with the high-speed mixer for 20min; heat treat at 80°C for 3h (heating rate 5°C / min); then add 3.75g of polymethacrylic acid and mix with the high-speed mixer for 20min; heat treat at 300°C for 0.5h (heating rate 1°C / min) to obtain modified rare earth polishing powder.

[0072] Embodiment 11

[0073] Wet simultaneous mixing: weigh 15.00 g of rare earth polishing powder into a high-speed mixer, add 0.15 g of metaphosphate, then add 0.30 g of polyacrylic acid, add deionized water to a beaker to a total weight of 20.00 g, and mix using a high-speed shear machine for 20 minutes; heat treat at 180°C for 3 hours (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0074] Example 12

[0075] Dry simultaneous mixing: weigh 50.00 g of rare earth polishing powder into a high-speed mixer, add 10.00 g of hexametaphosphoric acid, and then add 2.50 g of polyacrylic acid and potassium polymethacrylate respectively, and mix using a high-speed mixer for 20 minutes; heat treat at 80°C for 24 hours (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0076] Embodiment 13

[0077] Wet mixing first A and then B: weigh 15.00g of rare earth polishing powder into a beaker, add 2.25g of sodium hexametaphosphate, add deionized water to the beaker to a total weight of 20.00g; hydrothermally treat at 150°C for 2h (heating rate 5°C / min); then add 0.75g of sodium carboxymethyl cellulose, add deionized water to the beaker to a total weight of 30.00g, and stir with a high-efficiency shearing machine for 30min; hydrothermally treat at 60°C for 12h (heating rate 3°C / min) to obtain modified rare earth polishing powder.

[0078] Embodiment 14

[0079] Wet mixing: first B and then A: weigh 15.00g of rare earth polishing powder into a beaker, add 0.0375g of sodium carboxymethyl cellulose, add deionized water to the beaker to a total weight of 20.00g, and stir for 2h; heat treat at 120°C for 5h (heating rate 5°C / min); then add 0.075g of sodium hexametaphosphate, add deionized water to the beaker to a total weight of 30.00g, and stir evenly using a high-efficiency shearing machine; hydrothermally treat at 80°C for 5h (heating rate 3°C / min) to obtain modified rare earth polishing powder.

[0080] Embodiment 15

[0081] Dry simultaneous mixing: weigh 50.00 g of rare earth polishing powder into a high-speed mixer, add 0.05 g of hexametaphosphoric acid, and then add 0.05 g of polyacrylic acid and potassium polymethacrylate respectively, and mix using a high-speed mixer for 20 min; heat treat at 80°C for 24 h (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0082] Example 16

[0083] Dry simultaneous mixing: weigh 50.00 g of rare earth polishing powder into a high-speed mixer, add 10.00 g of hexametaphosphoric acid, and then add 5 g of polyacrylic acid and potassium polymethacrylate respectively, and mix using a high-speed mixer for 20 min; heat treat at 80°C for 24 h (heating rate 5°C / min) to obtain modified rare earth polishing powder.

[0084] Performance Testing:

[0085] Rare earth polishing powder characterization: The modified rare earth polishing powder obtained in the above embodiment was tested for P content by ICP, and its C content was tested by total organic carbon (TOC); the modified rare earth polishing powder obtained in the above embodiment was mixed with water to prepare a rare earth polishing liquid with a solid content of 5wt.%, and the particle size and Zeta potential were tested. The results are shown in Table 1.

[0086] Rare earth polishing liquid suspension stability: 100 mL of the rare earth polishing slurry prepared in the above embodiment was taken and placed in a transparent glass bottle with a scale, and the slurry stratification and the proportion of each layer in different time periods were observed and recorded. After the rare earth polishing slurry was left to stand for 24 hours, the volume ratio of the dispersed layer to the polishing slurry (V 分散层 / V 抛光液 ) are shown in Table 1. The rare earth polishing liquids of Examples 1 to 7 were left to stand for 24 hours and then dispersed. Figure 1 As shown, the Fourier transform infrared spectra of the rare earth polishing powder of Example 1 before and after modification are as shown in Figure 2As shown, the X-ray photoelectron spectra of the rare earth polishing powder of Example 6 before and after modification are as follows Figure 3 shown.

[0087] Polishing performance evaluation example:

[0088] Embodiment 17

[0089] The modified rare earth polishing powder obtained in Example 1 was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =95.00%.

[0090] Polishing performance evaluation: A TFT-LCD glass substrate (Thin film transistor-liquid crystal display, 80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0091] Embodiment 18

[0092] 50.00 g of the modified rare earth polishing powder obtained in Example 4 was weighed into a measuring cup, 2.50 g of metaphosphoric acid was added, and the mixture was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 h, V 分散层 / V 抛光液 =98.50%.

[0093] Polishing performance evaluation: K9 glass (50 mm × 50 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0094] Embodiment 19

[0095] The modified rare earth polishing powder obtained in Example 9 was mixed with water and sodium aminotri(methylenephosphonic acid) to prepare a rare earth polishing liquid with a solid content of 5 wt.%, wherein the weight percentage of sodium aminotri(methylenephosphonic acid) was 5%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =94.30%.

[0096] Polishing performance evaluation:K9 glass (50 mm × 50 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0097] Embodiment 20

[0098] 50.00 g of the modified rare earth polishing powder obtained in Example 10 was weighed into a measuring cup, 0.25 g of sodium hexametaphosphate was added, and the mixture was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. Ammonia water was used to adjust the pH to 7.50. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 h, V 分散层 / V 抛光液 =98.20%.

[0099] Polishing performance evaluation: The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0100] Embodiment 21

[0101] 50.00 g of the modified rare earth polishing powder obtained in Example 10 was weighed into a measuring cup, 0.50 g of sodium metaphosphate was added, and the mixture was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 h, V 分散层 / V 抛光液 =98.50%.

[0102] Polishing performance evaluation: The silicon oxide wafer (diameter 50 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0103] Embodiment 22

[0104] The modified rare earth polishing powder obtained in Example 13 was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =97.00%.

[0105] Polishing performance evaluation:The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0106] Embodiment 23

[0107] The modified rare earth polishing powder obtained in Example 14 was mixed with water to prepare a rare earth polishing liquid with a solid content of 5 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =98.50%.

[0108] Polishing performance evaluation: The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0109] Embodiment 24

[0110] The modified rare earth polishing powder obtained in Example 14 was mixed with water to prepare a rare earth polishing liquid with a solid content of 1 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =98.50%.

[0111] Polishing performance evaluation: The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0112] Embodiment 25

[0113] The modified rare earth polishing powder obtained in Example 14 was mixed with water to prepare a rare earth polishing liquid with a solid content of 10 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =98.50%.

[0114] Polishing performance evaluation: The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0115] Embodiment 26

[0116] The modified rare earth polishing powder obtained in Example 14 was mixed with water to prepare a rare earth polishing liquid with a solid content of 20 wt.%. The suspension stability test results showed that after the rare earth polishing liquid was left to stand for 24 hours, V 分散层 / V 抛光液 =98.50%.

[0117] Polishing performance evaluation: The TFT-LCD glass substrate (80 mm × 100 mm) was used as the polishing sample, the polishing pressure was 14 kPa, the polishing time was 20 min, the polishing disk speed was 45 rpm, and polishing was performed three times. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0118] Comparative Example 1

[0119] Weigh 45.00 g of rare earth polishing powder in a beaker, add deionized water to the beaker to a total weight of 900.00 g. At this time, the rare earth polishing liquid has a rare earth polishing powder content of 5 wt.%, and high-speed mechanical dispersion (2000 rpm) is applied for 1 hour to test the particle size and Zeta potential. The results are shown in Table 1.

[0120] Rare earth polishing liquid suspension stability: 100 mL of the above rare earth polishing liquid slurry was placed in a transparent glass bottle with scale, and the slurry stratification and the proportion of each layer were observed and recorded at different time periods. The suspension stability test results showed that the rare earth polishing liquid was completely settled after standing for 2 hours, and V 分散层 / V 抛光液 =0.00%.

[0121] Polishing performance evaluation: The TFT-LCD glass substrate (80mm×100mm) was used as the polishing sample, the polishing pressure was 14kPa, the polishing time was 20min, the polishing disk speed was 45rpm, and polishing was performed three times. The polishing damage was large. The polishing rate and the surface roughness of the polished sample are shown in Table 2.

[0122] Comparative Example 2

[0123] Weigh 50.00 g of rare earth polishing powder into a mixer, add only 0.25 g of sodium hexametaphosphate, and mix for 20 min; treat the mixed sample at 90 ° C for 5 h (heating rate 3 ° C / min) to obtain single A modified rare earth polishing powder, add water to prepare a rare earth polishing liquid with a solid content of 5 wt.%, and test the particle size and Zeta potential. The results are shown in Table 1.

[0124] Rare earth polishing liquid suspension stability:100 mL of the above rare earth polishing slurry was placed in a transparent glass bottle with scale, and the slurry stratification and the proportion of each layer were observed and recorded at different time periods. The suspension stability test results showed that after the rare earth polishing slurry was left to stand for 24 hours, V 分散层 / V 抛光液 =93.00%, but there is a 3mm hardening at the bottom, making it difficult to disperse.

[0125] Comparative Example 3

[0126] Weigh 15.00g of rare earth polishing powder in a beaker, add only 0.75g of sodium carboxymethyl cellulose solution (10wt.%), add deionized water to the beaker to a total weight of 30.00g; heat treat at 90°C for 8h (heating rate 3°C / min) with stirring to obtain single B modified rare earth polishing powder. Add water to prepare a rare earth polishing liquid with a solid content of 5wt.%, mechanically disperse (2000rpm) for 30min, and test the particle size and Zeta potential. The results are shown in Table 1.

[0127] Rare earth polishing liquid suspension stability: Take 100mL of the above rare earth polishing liquid slurry and place it in a transparent glass bottle with scale. Observe and record the slurry stratification and the proportion of each layer at different time periods. The suspension stability test results show that the suspension stability is poor, V 分散层 / V 抛光液 =0.00%, flocculated into a mass, and settled quickly (within 1 minute), and the polishing performance could not be evaluated.

[0128] Comparative Example 4

[0129] Weigh 15.00g of rare earth polishing powder in a beaker, add 2.25g of pyrophosphoric acid solution (10wt.%), add deionized water to the beaker to a total weight of 20.00g, stir for 1h; then add 7.5g of polymethacrylic acid solution (10wt.%), add deionized water to a total weight of 30.00g, stir evenly, and obtain unheat-treated modified rare earth polishing powder. Add water to prepare a rare earth polishing liquid with a solid content of 5wt.%, and test the particle size and Zeta potential. The results are shown in Table 1.

[0130] Rare earth polishing liquid suspension stability: 100 mL of the above rare earth polishing liquid slurry was taken and placed in a transparent glass bottle with a scale to observe and record the stratification of the slurry and the proportion of each layer in different time periods. The suspension stability test results showed that due to the lack of low-temperature heat treatment, the group and the particle surface could not form a strong interaction, resulting in poor dispersion stability of the rare earth polishing liquid. After standing for 24 hours, it solidified and became difficult to disperse again.

[0131] Table 1

[0132]

[0133]

[0134] Table 2

[0135]

[0136]

[0137] As can be seen from the above, compared with the comparative example, in the modified rare earth polishing powder of the present invention, the surface of the rare earth polishing powder contains two types of modified groups A and B, which have a strong interaction with the surface of the rare earth polishing powder, can synergistically inhibit the agglomeration of rare earth polishing powder particles, and form a flexible barrier layer on the particle surface to avoid solidification and hardening, enhance the surface stability of rare earth polishing powder particles, improve its suspension stability and redispersibility when used in rare earth polishing liquid, and increase the number of effective particles in the chemical mechanical polishing process, thereby well improving the contact condition between the polishing material and the polished workpiece, while maintaining a high polishing rate. Reduce polishing damage and improve polishing accuracy. At the same time, the rare earth polishing liquid containing this modified rare earth polishing powder has good suspension stability, a high polishing rate and extremely low polishing damage. After multiple high-speed centrifugal washings or recycling, it still has good redispersibility and suspension stability, and the polishing consistency is greatly improved. In addition, it can be seen that when each parameter is within the preferred range of the present invention, the polishing performance is better.

[0138] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A modified rare earth polishing powder, characterized in that: It includes rare earth polishing powder and a modified group bonded to the surface thereof, wherein the modified group includes a type A group and a type B group, wherein: The A-type group is a phosphorus-containing group; The B-type group is a carboxyl group having a long-chain structure.

2. The modified rare earth polishing powder according to claim 1, characterized in that: The modified rare earth polishing powder contains P element and C element. By weight percentage, the P element content in the modified rare earth polishing powder is 0.01-3%, and the C element content is 0.01-5%; preferably, the P element content in the modified rare earth polishing powder is 0.05-3%, and the C element content is 0.01-1%; and / or The type A group is generated by a bonding reaction between a phosphorus-containing group precursor and the rare earth polishing powder; the phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and sodium salts, potassium salts and ammonium salts of the above substances; preferably, the organic phosphorus-containing group precursor includes one or more of phosphates and their derivatives; and / or The type B group is produced by a bonding reaction between a long-chain carboxyl precursor and the rare earth polishing powder; preferably, the long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and its sodium salt, alginate and its sodium salt, acrylic acid polymer and its derivatives; more preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate.

3. The modified rare earth polishing powder according to claim 1 or 2, characterized in that: The chemical formula of the rare earth polishing powder is Ce 1-x M x O y N z , wherein M includes one or more of rare earth elements except cerium, transition metal elements, alkaline earth metal elements, alkali metal elements, aluminum, tin, silicon, boron and arsenic, and N includes one or more of F, Cl and S; 0≤x≤0.6, 1.0<y≤2.0, 0≤z≤0.9; Preferably, M comprises one or more of lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, ytterbium, yttrium, titanium, zirconium, iron, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; More preferably, M comprises one or more of lanthanum, praseodymium, neodymium, samarium, ytterbium, yttrium, titanium, zirconium, magnesium, sodium, calcium, aluminum, tin, silicon, boron and arsenic; Preferably, 0≤x≤0.4, 1.2≤y≤2.0, and 0≤z≤0.

65.

4. The modified rare earth polishing powder according to any one of claims 1 to 3, characterized in that: The modified rare earth polishing powder has a D 50 It is 0.01 to 5.0 μm, preferably 0.01 to 2.0 μm, and more preferably 0.1 to 1.5 μm.

5. The method for preparing the modified rare earth polishing powder according to any one of claims 1 to 4, characterized in that: The rare earth polishing powder is mixed with a phosphorus-containing group precursor and a long-chain carboxyl precursor, and reacted under heat treatment conditions to obtain the modified rare earth polishing powder; The phosphorus-containing group precursor is used to chemically bond the type A groups on the surface of the rare earth polishing powder, and the long-chain carboxyl precursor is used to chemically bond the type B groups on the surface of the rare earth polishing powder.

6. The preparation method according to claim 5, characterized in that: The phosphorus-containing group precursor includes an inorganic phosphorus-containing group precursor and an organic phosphorus-containing group precursor; preferably, the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and sodium salts, potassium salts and ammonium salts of the above substances; preferably, the organic phosphorus-containing group precursor includes one or more of phosphate esters and their derivatives; and / or The long-chain carboxyl precursor includes one or more of carboxymethyl cellulose and its sodium salt, alginate and its sodium salt, acrylic acid polymer and its derivatives; preferably, the acrylic acid polymer includes one or more of maleic acid-acrylic acid copolymer, maleic acid-acrylic acid copolymer sodium salt, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, polymethacrylic acid, sodium polymethacrylate, potassium polymethacrylate, and ammonium polymethacrylate.

7. The preparation method according to claim 5 or 6, characterized in that: The weight ratio of the rare earth polishing powder to the phosphorus-containing group precursor and the long-chain carboxyl precursor is 100: (0.1-20):(0.1-10), preferably 100:(0.5-20):(0.25-8); and / or The mixing is wet mixing or dry mixing; preferably, during the wet mixing process, the pH of the system is controlled to be 6.0 to 9.0; and / or The heat treatment temperature is 50-300°C, the time is 0.5-48h, and the heating rate is 1-10°C / min; preferably, the heat treatment temperature is 100-250°C.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The mixing includes the following methods: Method 1: mixing the rare earth polishing powder with the phosphorus-containing group precursor and performing a first heat treatment to obtain a first product; then mixing the first product with the long-chain carboxyl precursor and performing a second heat treatment to obtain the modified rare earth polishing powder; or Method 2: mixing the rare earth polishing powder with the long-chain carboxyl precursor and performing a third heat treatment to obtain a second product; then mixing the second product with the phosphorus-containing group precursor and performing a fourth heat treatment to obtain the modified rare earth polishing powder; or Mode three, mixing the rare earth polishing powder with the phosphorus-containing group precursor and the long-chain carboxyl precursor at the same time, and performing the heat treatment to obtain the modified rare earth polishing powder; The temperatures of the first heat treatment, the second heat treatment, the third heat treatment and the fourth heat treatment are independently 50 to 300° C., the times are independently 0.5 to 48 hours, and the heating rates are independently 1 to 10° C. / min.

9. A rare earth polishing liquid, characterized in that: The modified rare earth polishing powder according to any one of claims 1 to 4, a surfactant, a pH regulator and water; Preferably, the rare earth polishing liquid comprises 1 to 20% of the modified rare earth polishing powder by weight; more preferably 5 to 10%; Preferably, the rare earth polishing liquid comprises 0 to 5% of the surfactant by weight, and the surfactant comprises one or more of aminotrimethylphosphonic acid, aminotrimethylphosphonic acid sodium salt, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, sodium dodecyl sulfonate, polyethylene glycol, polyvinyl alcohol and polymethacrylate; Preferably, the rare earth polishing liquid also includes an inorganic phosphorus-containing group precursor, the weight ratio of the modified rare earth polishing powder to the inorganic phosphorus-containing group precursor is 100:(0.5~5), and the inorganic phosphorus-containing group precursor includes one or more of metaphosphoric acid, hexametaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid and the sodium salts, potassium salts and ammonium salts of the above substances.

10. Use of the modified rare earth polishing powder according to any one of claims 1 to 4 and / or the rare earth polishing liquid according to claim 9 in the fields of flat glass, mobile phone cover glass, optical glass, liquid crystal display glass, glass substrate and integrated circuit.

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