Polyether ester, preparation method thereof, cutting fluid containing polyether ester and application

Abstract

The invention discloses polyether ester, a preparation method thereof, cutting fluid containing the polyether ester and application. The polyether ester comprises a structural formula as shown in a formula I, R is C3-C12 alkyl, a is an integer selected from 1-50, b is an integer selected from 1-50, c is an integer selected from 0-50, and d is an integer selected from 0-50. The molecular weight distribution index of the polyether ester is 1.02 to 1.30. The polyether ester provided by the invention has good silicon powder dispersibility and wettability, and when the cutting fluid prepared from the polyether ester is applied to silicon wafer cutting, the obtained silicon wafer has good quality uniformity, and the number of qualified products obtained after cutting is large. # imgabs0 # I

Description

Technical Field

[0001] The invention relates to a polyether ester and a preparation method thereof, a cutting fluid containing the polyether ester and application thereof. Background Art

[0002] Diamond wire cutting technology is in a stage of vigorous development. However, the cutting process may cause the diamond wire to break due to various factors, which will not only affect the quality of the silicon wafer, but also increase the breakage rate of the diamond wire and increase the cost. Therefore, in the process of silicon wafer cutting, the cutting fluid plays a vital role. It can quickly and evenly wet the surface of the silicon wafer, improve the cutting effect and accuracy, effectively reduce the heat and temperature during the cutting process, protect the quality of the crystalline silicon wafer, and also play a certain protective role on the diamond wire to reduce the wear of the diamond wire. However, the current existing technology for improving the performance of the cutting fluid mainly focuses on the need for it to have excellent wetting and dispersing properties and lubrication functions, thereby improving the efficiency of silicon wafer cutting and protecting the cutting equipment and silicon wafers, but rarely pays attention to the dispersion performance of the cutting fluid on silicon powder and the protective effect on the diamond wire.

[0003] In summary, the A+ grade yield of silicon wafer cutting fluid in the prior art is low and the TTV (total thickness variation) is large during use, which limits the production capacity and quality of silicon wafers. Therefore, seeking a cutting fluid with excellent performance is of great significance to the silicon wafer production process. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art that the polyether has poor silicon powder dispersibility and wettability, and the silicon wafers obtained by cutting the single crystal silicon cutting fluid prepared from the polyether have poor quality uniformity and few qualified products during use, and provide a polyether ester and its preparation method, a cutting fluid containing the same and its application. The polyether ester provided by the present invention has good silicon powder dispersibility and wettability, and the silicon wafers obtained by the cutting fluid prepared from the polyether ester when used for silicon wafer cutting have good quality uniformity, and many qualified products are obtained after cutting.

[0005] The present invention solves the above technical problems through the following solutions.

[0006] The present invention provides a polyether ester comprising a structural formula as shown in Formula I:

[0007] I

[0008] Where R is C3-C 12 An alkyl group, a is an integer selected from 1-50, b is an integer selected from 1-50, c is an integer selected from 0-50, and d is an integer selected from 0-50;

[0009] The molecular weight distribution index of the polyetherester is 1.02-1.30.

[0010] In the present invention, the weight average molecular weight of the polyether ester can be selected from 300-10000, preferably 1000-5000, such as 1127, 2669 or 3196.

[0011] In the present invention, the molecular weight distribution index (PDI) of the polyetherester is preferably 1.03-1.20, such as 1.04, 1.13 or 1.18.

[0012] In the present invention, the R is preferably C5-C 12 An alkyl group such as hexyl, nonyl or dodecyl.

[0013] In the present invention, a is preferably 3-20, such as 5, 10, 12 or 15.

[0014] In the present invention, b is preferably 5-30, such as 6, 12, 13 or 15.

[0015] In the present invention, c is preferably 5-30, such as 5, 11, 12 or 14.

[0016] In the present invention, the d is preferably 3-20, such as 4, 9, 11, 12 or 14.

[0017] In some specific embodiments, in the polyetherester, a is 5, b is 6, c is 5, and d is 4.

[0018] In some specific embodiments, in the polyetherester, a is 12, b is 13, c is 12, and d is 11.

[0019] In some specific embodiments, in the polyetherester, a is 15, b is 15, c is 14, and d is 14.

[0020] The present invention also provides a method for preparing polyether ester, which comprises the following steps: mixing an alkyl phosphate having 3 to 12 carbon atoms and a catalyst, introducing ethylene oxide, performing a first reaction, performing a first aging, and then introducing propylene oxide, performing a second reaction, and performing a second aging to obtain the polyether ester; the molar ratio of the ethylene oxide to the propylene oxide is (1-2):1.

[0021] In the present invention, the alkyl phosphate is preferably an alkyl phosphate having 5-12 carbon atoms, such as one or more of hexyl phosphate, nonyl phosphate and dodecyl phosphate, such as hexyl phosphate, nonyl phosphate, dodecyl phosphate, or hexyl phosphate and dodecyl phosphate.

[0022] In the present invention, the type of the catalyst may be one or more of potassium hydroxide (KOH), potassium methoxide, phosphazene series catalyst (PZN) and dimethyl carbonate, such as potassium methoxide.

[0023] In the present invention, the weight of the catalyst may be 0.1%-0.5% of the "total weight of the alkyl phosphate, the ethylene oxide and the propylene oxide", preferably 0.12%-0.30%, such as 0.15%, 0.12% or 0.27%.

[0024] In the present invention, the molar ratio of the alkyl phosphate ester to the catalyst is (0.3-3):0.07, preferably (0.5-2.8):0.07, such as 2.74:0.07, 1.34:0.07 or 0.68:0.07.

[0025] In the present invention, the mixing is preferably carried out at 100-120° C., for example, 115° C. After the mixing and before the introduction of ethylene oxide, a dehydration step is preferably carried out. The dehydration time is preferably 30-40 minutes, for example, 40 minutes.

[0026] In the present invention, the initial temperature of the system when introducing ethylene oxide is preferably 120-140°C, such as 130°C.

[0027] In the present invention, the temperature of the first reaction may be 140-160° C., preferably 142-150° C., for example 145° C. The temperature of the first aging may be 140-160° C., for example 150° C. The time of the first aging may be 50-70 min, preferably 60 min.

[0028] In the present invention, after the first aging and before the introduction of propylene oxide, preferably nitrogen replacement and cooling steps are further performed. The end point of the cooling can be 120-130°C, for example 125°C.

[0029] In the present invention, the temperature of the second reaction may be 130-150° C., preferably 132-140° C., for example 135° C. The temperature of the second aging may be 130-160° C., for example 135 or 145° C. The time of the second aging may be 2-3 h, for example 2.5 h.

[0030] In the present invention, the molar ratio of the ethylene oxide to the propylene oxide may be (1.05-1.25):1, such as 1.20:1, 1.08:1 or 1.00:1.

[0031] In the present invention, the molar ratio of the alkyl phosphate to the ethylene oxide may be (20-100):1, preferably (22-95):1, such as 91.33:1, 32.68:1 or 23.45:1.

[0032] In the present invention, the molar ratio of the alkyl phosphate to the propylene oxide may be (20-120):1, preferably (22-110):1, such as 109.6:1, 35.26:1 or 23.45:1.

[0033] In the present invention, after the second aging, it is preferred that the first cooling, vacuum degassing and second cooling steps are further included, and the end point temperature of the first cooling is higher than the end point temperature of the second cooling. The end point of the first cooling can be 110-130°C, for example, 120°C. The time of the vacuum degassing can be 30-40min, for example, 35min. The end point of the second cooling can be 50-70°C, for example, 60°C.

[0034] The present invention also provides a polyether ester prepared by the above-mentioned preparation method of polyether ester.

[0035] In the present invention, the polyether ester is preferably one or more of hexyl phosphate polyoxyethylene ether polyoxypropylene ether, nonyl phosphate polyoxyethylene polyoxypropylene ether and dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, for example, hexyl phosphate polyoxyethylene ether polyoxypropylene ether, nonyl phosphate polyoxyethylene polyoxypropylene ether, dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, or hexyl phosphate polyoxyethylene ether polyoxypropylene ether and dodecyl phosphate polyoxyethylene ether polyoxypropylene ether.

[0036] Wherein, when the polyether ester is hexyl phosphate polyoxyethylene ether polyoxypropylene ether, the weight average molecular weight of the hexyl phosphate polyoxyethylene ether polyoxypropylene ether may be 1000-2000, for example, 1127.

[0037] Wherein, when the polyether ester is polyoxyethylene polyoxypropylene nonyl phosphate ether, the weight average molecular weight of the polyoxyethylene polyoxypropylene nonyl phosphate ether may be 2000-3000, for example, 2669.

[0038] Wherein, when the polyether ester is dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, the weight average molecular weight of the dodecyl phosphate polyoxyethylene ether polyoxypropylene ether may be 3000-4000, for example, 3196.

[0039] The present invention also provides a cutting fluid, which comprises the polyether ester as described above.

[0040] In the present invention, the cutting fluid is preferably a silicon wafer cutting fluid.

[0041] In a preferred embodiment of the present invention, the cutting fluid comprises the following components, and the percentage is the percentage of the mass of each component to the total mass of the cutting fluid:

[0042] 5-50% of the aforementioned polyetherester;

[0043] Isomeric alcohol polyoxyethylene ether 10-30%;

[0044] Defoaming agent 0.1-0.3%;

[0045] Solvent 3-10%;

[0046] pH adjuster 0.01-0.03%

[0047] Water balance.

[0048] Wherein, the mass percentage of the polyether ester is preferably 10-30%, such as 18%, 10% or 25%.

[0049] Among them, the isomeric alcohol polyoxyethylene ether is preferably one or more of isooctyl alcohol polyoxyethylene ether polyoxypropylene ether, isononyl alcohol polyoxyethylene ether polyoxypropylene ether and isomeric tridecyl alcohol polyoxyethylene ether polyoxypropylene ether, for example, isooctyl alcohol polyoxyethylene ether polyoxypropylene ether and / or isononyl alcohol polyoxyethylene ether polyoxypropylene ether.

[0050] Wherein, the weight average molecular weight of the isomeric alcohol polyoxyethylene ether is preferably 250-400, such as 250-350 or 300-400.

[0051] Wherein, the molecular weight distribution index of the isomeric alcohol polyoxyethylene ether is preferably 1.2-1.4.

[0052] Wherein, the mass percentage of the isomeric alcohol polyoxyethylene ether is preferably 20-28%, such as 22% or 23%.

[0053] The defoamer may be a conventional defoamer in the art, such as an organosilicon defoamer. The type of the organosilicon defoamer may be one or more of BYK-012, BYK-016, BYK-024, BYK-018 and BYK-028, such as BYK-012, BYK-016 or BYK-018.

[0054] Wherein, the mass percentage of the defoaming agent is preferably 0.10-0.25%, such as 0.15% or 0.20%.

[0055] The type of the solvent may be conventional in the art, preferably one or more of dipropylene glycol, isopropyl alcohol, isohexylene glycol and ethylene glycol monobutyl ether, such as isohexylene glycol, isopropyl alcohol, ethylene glycol monobutyl ether, or isohexylene glycol and isopropyl alcohol.

[0056] Wherein, the mass percentage of the solvent is preferably 5.0-9.0%, such as 6.0% or 8.0%.

[0057] The pH regulator can preferably adjust the pH of the system to 6-7. The type of the pH regulator is preferably triethanolamine. The mass percentage of the pH regulator is preferably 0.015-0.025%, for example 0.02%.

[0058] In a preferred embodiment of the present invention, the cutting fluid is prepared by the following method: mixing the polyether ester, isomeric alcohol polyoxyethylene ether, defoaming agent, solvent and water as described above.

[0059] The present invention provides the use of the above-mentioned polyether ester or cutting fluid in the preparation of silicon wafers.

[0060] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0061] Except for the polyether ester obtained by the preparation method of the polyether ester clearly described in the present invention, the reagents and raw materials used in the present invention are all commercially available.

[0062] The positive and progressive effects of the present invention are:

[0063] The polyether ester provided by the present invention has better silicon powder dispersibility and wettability; when the polyether ester is used in cutting fluid, it still has excellent silicon powder dispersibility and lubricity, the silicon wafers obtained by cutting have better quality uniformity, and more qualified products are obtained after cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is the infrared spectrum of the polyether ester prepared in Example 1.

[0065] Figure 2 It is the scoring standard for the floating condition of silica powder.

[0066] Figure 3 It is a scoring standard for the dispersion state of silicon powder at the bottom.

[0067] Figure 4 Part a, part b and part c are the silicon powder dispersion and floating conditions of the polyether ester prepared in Example 1, the polyether in Comparative Example 4 and the polyether in Comparative Example 7, respectively.

[0068] Figure 5 Part a, part b and part c are the bottom sludge dispersion conditions of the polyether ester prepared in Example 1, the polyether in Comparative Example 4 and the polyether in Comparative Example 7, respectively. DETAILED DESCRIPTION

[0069] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0070] In the following examples, EO represents ethylene oxide; and PO represents propylene oxide.

[0071] Isooctyl alcohol polyoxyethylene ether polyoxypropylene ether and isononyl alcohol polyoxyethylene ether polyoxypropylene ether were purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.; defoamers BYK-016, BYK-018 and BYK-012 were purchased from BYK Additives (Shanghai) Co., Ltd.; block polyether 374RA was purchased from Zhejiang Royal Madrid New Materials Technology Co., Ltd.; L64 was purchased from Jiahua Chemical (Shanghai) Co., Ltd.

[0072] Example 1

[0073] (1) Preparation of polyether ester:

[0074] In a high-pressure reactor, add 500g of initiator (hexyl phosphate, molar number is 2.74mol), then add 5.00g of potassium methoxide (molar number is 0.07mol) catalyst, heat to 115℃ for dehydration for 40min, heat to 130℃ and pass 1.33kg EO (molar number is 0.030mol), the reaction temperature is controlled at about 145℃, EO is matured after passing, the temperature is maintained at about 150℃, the maturation time is about 60min, nitrogen replacement, the temperature in the reactor drops to 125℃, and 1.43kg PO (molar number is 0.025mol) is started to pass, the reaction temperature is controlled at 135℃, PO is matured for 2.5 hours after passing, the temperature in the reactor is maintained at about 135℃, and the temperature starts to drop to about 120℃ after the maturation, vacuum degassing for 30min, vacuum cooling by about 60℃ after the end, neutralization, and the material can obtain hexyl phosphate polyoxyethylene polyoxypropylene ether.

[0075] The prepared polyether ester is hexyl phosphate polyoxyethylene ether polyoxypropylene ether, with Mw of 1127, PDI of 1.13, and a=5, b=6, c=5, and d=4 in the general structural formula.

[0076] (2) Preparing a cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid,

[0077] Hexyl phosphate polyoxyethylene polyoxypropylene ether: 25 parts

[0078] 2-Ethylene Oxyethyl Ether Polyoxypropylene Ether (MW = 250-350; PDI = 1.2-1.4): 8 parts;

[0079] Isononyl alcohol polyoxyethylene ether polyoxypropylene ether (MW = 300-400; PDI = 1.2-1.4): 12 parts

[0080] Defoamer BYK-016: 0.2 parts

[0081] Isohexanediol: 5 parts

[0082] Triethanolamine: 0.02 parts

[0083] Water: 49.78 parts.

[0084] Example 2

[0085] (1) Preparation of polyether ester:

[0086] In a high-pressure reactor, add 300g of initiator (nonyl phosphate, molar number is 1.34mol), then add 5.00g of potassium methoxide (molar number is 0.07mol) catalyst, heat to 120℃ for dehydration for 40min, heat to 140℃ and pass 1.82kg EO (molar number is 0.041mol), the reaction temperature is controlled at about 145℃, EO is passed through and matured, the temperature is maintained at about 150℃, the maturation time is about 60min, nitrogen replacement, the temperature in the reactor drops to 125℃, and 2.20kg PO (molar number is 0.038mol) is started to pass through, the reaction temperature is controlled at 135℃, PO is passed through and matured for 2.5 hours, the temperature in the reactor is maintained at about 145℃, and the temperature starts to drop to about 120℃ after the maturation, vacuum degassing for 40min, vacuum end temperature drop by about 60℃, neutralization, and the material can be obtained as nonyl phosphate polyoxyethylene polyoxypropylene ether.

[0087] The prepared polyether ester is polyoxyethylene polyoxypropylene nonyl phosphate ether, with Mw of 2669, PDI of 1.04, and a=12, b=13, c=12, and d=11 in the general structural formula.

[0088] (2) Preparing a cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid,

[0089] Nonyl phosphate polyoxyethylene polyoxypropylene ether: 20 parts

[0090] Isooctanol polyoxyethylene ether polyoxypropylene ether: 10 parts

[0091] Isononyl alcohol polyoxyethylene ether polyoxypropylene ether: 12 parts

[0092] Defoamer BYK-018: 0.15 parts

[0093] Isopropyl alcohol: 8 parts

[0094] Triethanolamine: 0.02 parts

[0095] Water: 49.83 parts.

[0096] Example 3

[0097] (1) Preparation of polyether ester:

[0098] In a high-pressure reactor, add 182g of initiator (dodecyl phosphate, molar number is 0.68mol), then add 5.00g of potassium methoxide (molar number is 0.07mol) catalyst, heat to 120℃ for dehydration for 40min, heat to 140℃ and pass 1.28kg EO (molar number is 0.029mol), the reaction temperature is controlled at about 145℃, EO is matured after passing, the temperature is maintained at about 150℃, the maturation time is about 60min, nitrogen replacement, the temperature in the reactor drops to 125℃, 1.68kg PO (molar number is 0.029mol) is started, the reaction temperature is controlled at 135℃, PO is matured for 2.5 hours after passing, the temperature in the reactor is maintained at about 145℃, and the temperature starts to drop to about 120℃ after the maturation, vacuum degassing for 40min, vacuum cooling by about 60℃ after the end, neutralization, and the discharge material can obtain dodecyl phosphate polyoxyethylene polyoxypropylene ether.

[0099] The prepared polyether ester is dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, with Mw of 3196 and PDI of 1.18. In the general structural formula, a=15, b=15, c=14, and d=14.

[0100] (2) Preparing a cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid,

[0101] Dodecyl phosphate polyoxyethylene ether polyoxypropylene ether: 18 parts

[0102] Isooctanol polyoxyethylene ether polyoxypropylene ether: 8 parts

[0103] Isononyl alcohol polyoxyethylene ether polyoxypropylene ether: 15 parts

[0104] Defoamer BYK-012: 0.2 parts

[0105] Ethylene glycol monobutyl ether: 6 parts

[0106] Triethanolamine: 0.02 parts

[0107] Water: 52.78 parts.

[0108] Example 4

[0109] (1) Preparation of polyether ester:

[0110] For the preparation method of hexyl phosphate polyoxyethylene ether polyoxypropylene ether, see Example 1; for the preparation method of dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, see Example 3.

[0111] (2) Preparing a cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid,

[0112] Hexyl phosphate polyoxyethylene ether polyoxypropylene ether (Mw=1127): 10 parts

[0113] Dodecyl phosphate polyoxyethylene ether polyoxypropylene ether (Mw=3196): 10 parts

[0114] Isooctanol polyoxyethylene ether polyoxypropylene ether: 10 parts

[0115] Isononyl alcohol polyoxyethylene ether polyoxypropylene ether: 12 parts

[0116] Defoamer BYK-012: 0.15 parts

[0117] Isohexanediol: 3 parts

[0118] Isopropyl alcohol: 3 parts

[0119] Triethanolamine: 0.02 parts

[0120] Water: 51.83 parts.

[0121] Comparative Example 1

[0122] Commercially available crystalline silicon cutting fluid product 1.

[0123] Comparative Example 2

[0124] Commercially available crystalline silicon cutting fluid products 2.

[0125] Comparative Example 3

[0126] Commercially available crystalline silicon cutting fluid products 3.

[0127] Comparative Example 4

[0128] The polyetherester of Example 1 was replaced by block polyether 374RA (reverse EO / PO block copolymer (ethylene oxide-propylene oxide block copolymer), MW=2376);

[0129] The block polyether is mixed according to the following formula to prepare a cutting fluid:

[0130] 374RA: 25 copies

[0131] 2-Ethylene Oxyethyl Ether Polyoxypropylene Ether (MW = 250-350; PDI = 1.2-1.4): 8 parts;

[0132] Isononyl alcohol polyoxyethylene ether polyoxypropylene ether (MW = 300-400; PDI = 1.2-1.4): 12 parts

[0133] Defoamer BYK-016: 0.2 parts

[0134] Isohexanediol: 5 parts

[0135] Triethanolamine: 0.02 parts

[0136] Water: 49.78 parts.

[0137] Comparative Example 5

[0138] (1) Preparation of polyether ester:

[0139] In a high-pressure reactor, add 500g of initiator (hexyl phosphate, molar number is 2.74mol), then add 5.00g of potassium methoxide (molar number is 0.07mol) catalyst, heat to 115℃ for dehydration for 40min, heat to 125℃, and introduce pre-mixed EO+PO (1.33kg EO (molar number is 0.030mol), +1.43kg PO (molar number is 0.025mol)), the reaction temperature is controlled at about 135℃, and mature for 3.0 hours. The temperature in the reactor is maintained at about 140℃. After the aging, the temperature begins to drop to about 120℃, and vacuum degassing is performed for 30min. After the vacuum is finished, the temperature is dropped by about 60℃, neutralized, and the material is discharged to obtain mixed hexyl phosphate polyoxyethylene polyoxypropylene ether.

[0140] The prepared polyether ester is a mixed embedded hexyl phosphate polyoxyethylene ether polyoxypropylene ether, with Mw of 1113 and PDI of 1.21.

[0141] (2) Preparation of cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid. The formula of the cutting fluid is the same as that of Example 1.

[0142] Comparative Example 6

[0143] (1) Preparation of polyether ester:

[0144] In a high-pressure reactor, add 500g of initiator (hexyl phosphate, molar number is 2.74mol), then add 5.00g of potassium methoxide (molar number is 0.07mol) catalyst, heat to 115℃ for dehydration for 40min, start to pass 1.43kg PO (molar number is 0.025mol), the reaction temperature is controlled at 135℃, PO is matured after passing, the temperature is maintained at about 140℃, the maturation time is about 60min, nitrogen replacement, the temperature in the reactor drops to 130℃, start to pass 1.33kg EO (molar number is 0.030mol), the reaction temperature is controlled at 135℃, EO is matured for 2.5 hours after passing, the temperature in the reactor is maintained at about 140℃, and the temperature starts to drop to about 120℃ after the maturation. Vacuum degassing for 30min, vacuum cooling by about 60℃ after the end of vacuum, neutralization, and the material can obtain cis-hexyl phosphate polyoxyethylene polyoxypropylene ether.

[0145] The prepared polyether ester is cis-hexyl phosphate polyoxyethylene ether polyoxypropylene ether (structural formula is the following formula II), Mw is 1058, PDI is 1.16, and a=6, b=4, c=3, d=5 in the general structural formula.

[0146] II

[0147] (2) Preparation of cutting fluid: The polyether ester prepared in step (1) is mixed according to the following formula to prepare a cutting fluid. The formula of the cutting fluid is the same as that of Example 1.

[0148] Comparative Example 7

[0149] The polyetherester of Example 1 was replaced by block polyether L64 (MW=2900).

[0150] Since the foaming height and defoaming time of the polyether were too poor, the subsequent cutting fluid formulation was not tested.

[0151] Effect Example 1

[0152] The polyether ester prepared by the present invention is characterized:

[0153] (1) Structural characterization

[0154] Infrared spectrum test

[0155] The infrared spectrum test was conducted using a Nicolet iG50 FTIR infrared spectrometer. The ATR mode was started, the air background was tested, and polyether ester was dripped onto the diamond crystal on the ATR module at 400 cm -1 -4000cm -1 Area scan 32 times, resolution 4cm -1 The results are as follows Figure 1 shown.

[0156] Figure 1 This is the infrared spectrum of the polyether ester prepared in Example 1. In the figure, 1220-1240 cm -1 There is a symmetrical stretching vibration absorption peak of the phosphate group, 1330-1360cm -1 The peak position of 900-1100cm corresponds to the stretching vibration of the P=O (phosphorus-oxygen double bond in the phosphate group) of the phosphate group. -1 There are characteristic absorption peaks of EO and PO nearby, which proves that the molecular structure of the polyether ester contains characteristic groups such as phosphate bonds and polyether side chains.

[0157] (2) Testing methods for molecular weight and PDI

[0158] The molecular weight and PDI of polyether ester were determined by Waters 1515 gel permeation chromatography (GPC) and Waters 2414 refractive index detector. First, a polyether ester solution with a concentration of 1.5 mg / mL was prepared, tetrahydrofuran (THF) was used as the mobile phase, and polyethylene glycol (PEG) with different molecular weights was used as the standard sample.

[0159] The test results are shown in Table 1.

[0160] Table 1

[0161]

[0162] Effect Example 2

[0163] The polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7 were tested for dynamic surface tension, electrical conductivity, foaming height and foaming time. The effect data are shown in Table 2.

[0164] The dynamic surface tension test method is as follows: the polyether ester prepared in Example 1 and the polyethers in Comparative Examples 4 and 7 are respectively prepared with pure water to prepare a 1% concentration of cutting fluid, stirred evenly, and then tested with KRUSS BP100 to record the surface tension of 6 bubbles / second. The dynamic surface tension represents the wettability of the polyether ester, and the lower the dynamic surface tension, the better the wettability.

[0165] The test method of conductivity is as follows: the polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7 are respectively prepared into 1% concentration cutting liquid using pure water, stirred evenly, tested using a conductivity meter, and recorded the readings.

[0166] The test method for the foaming height and the defoaming time is as follows: the polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7 are respectively prepared with pure water into a 1% concentration cutting liquid, and after stirring evenly, 50 mL of the cutting liquid is taken into a 100 mL stoppered measuring cylinder, and the timing is immediately started after oscillating up and down 20 times, and the foam height (i.e., the foaming height) is immediately read, and the time for the foam to disappear is observed as the defoaming time.

[0167] Table 2

[0168]

[0169] As can be seen from Table 2, compared with the polyethers of Comparative Examples 4 and 7, the polyether ester prepared in Example 1 has a lower dynamic surface tension, which shows that the polyether ester prepared in Example 1 has better wettability. Compared with the polyethers of Comparative Examples 4 and 7, the polyether ester prepared in Example 1 has a lower foaming height and a shorter defoaming time, which shows that the polyether ester prepared in Example 1 has better low-foaming performance.

[0170] Observe the silicon powder dispersibility of the polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7. The test method for silicon powder dispersibility is as follows: the polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7 are mixed with deionized water to prepare 50 mL of a test solution with a concentration of 0.5%, add 3% silicon powder with a D50 of 500 microns, stir for 5 minutes, shake up and down 10 times, leave for 24 hours, and observe the floating of silicon powder; the test solution that has been left for 24 hours is gently shaken up and down 5 times without applying additional force, and inverted for 5 minutes, and the dispersion of silicon powder at the bottom is recorded.

[0171] The scoring criteria for silica fume floating conditions are as follows: Figure 2 ; The scoring criteria for the dispersion of silicon powder at the bottom are as follows: Figure 3 .

[0172] The silicon powder dispersibility results of the polyether ester prepared in Example 1 and the polyethers of Comparative Examples 4 and 7 are as follows: Figure 4 , Figure 5 And as shown in Table 3. Figure 4 Part a, part b and part c are the silicon powder dispersion and floating conditions of the polyether ester prepared in Example 1, the polyether in Comparative Example 4 and the polyether in Comparative Example 7, respectively. Figure 5 Part a, part b and part c are the bottom sludge dispersion conditions of the polyether ester prepared in Example 1, the polyether in Comparative Example 4 and the polyether in Comparative Example 7, respectively.

[0173] Table 3

[0174] Example 1 Comparative Example 4 Comparative Example 7 Silica fume floating score 5 3 5 Bottom Scattering Rating 4 3 4

[0175] As shown in Table 3, compared with Comparative Example 4, when the polyether ester polyether prepared in Example 1 disperses silicon powder, no silicon powder floats on the wall and the liquid surface, and after inversion, the silicon mud at the bottom can be evenly dispersed. It can be seen that the polyether ester prepared in Example 1 has better silicon powder dispersibility.

[0176] Effect Example 3

[0177] The cutting fluids prepared in Examples 1-4 and the cutting fluids in Comparative Examples 1-6 were tested for dynamic surface tension, conductivity, bubble height and bubble time. The effect data are shown in Table 4.

[0178] The dynamic surface tension test method is as follows: the cutting fluids prepared in Examples 1-4 and the cutting fluids in Comparative Examples 1-6 are tested for dynamic surface tension using KRUSS BP100, and the surface tension at 6 bubbles / second is recorded. The dynamic surface tension represents the wettability of the polyether ester, and the lower the dynamic surface tension, the better the wettability.

[0179] The test method of electrical conductivity is as follows: the cutting fluids prepared in Examples 1-4 and the cutting fluids in Comparative Examples 1-6 are tested respectively using a conductivity meter and the readings are recorded.

[0180] The test method for the foam height and the defoaming time is as follows: 50 mL of the cutting liquid prepared in Examples 1-4 and the cutting liquid in Comparative Examples 1-6 are respectively taken into a 100 mL stoppered measuring cylinder, and the timing is immediately started after 20 up and down oscillations, and the foam height (i.e., the foam height) is immediately read, and the time when the foam disappears is observed as the defoaming time.

[0181] Table 4

[0182]

[0183] As shown in Table 4, compared with the cutting fluids of Comparative Examples 1-6, the cutting fluids of Examples 1-4 can simultaneously have lower dynamic surface tension, lower conductivity, lower bubble height and shorter defoaming time. It can be seen that the cutting fluids of Examples 1-4 have better wettability and better low-foaming performance.

[0184] Effect Example 4

[0185] The cutting fluids prepared in Examples 1-4 and the cutting fluids in Comparative Examples 1-6 were subjected to cutting experiments for comparison and testing, and the effect data are shown in Table 5.

[0186] The cutting fluids prepared in the above-mentioned Examples 1-4 and the cutting fluids of Comparative Examples 1-6 were diluted with deionized water (the dilution ratio was a mass ratio of the cutting fluid to the deionized water of 1:(120-150)), and under the same cutting parameter conditions (using a 30-micron Yujing carbon steel wire diameter, a cutting line speed of 2400 m / min, and a left and right line tension of about 3.7 N), a solar-grade 210 mm size monocrystalline silicon wafer half (with a thickness of 125 microns) was cut, and the A+ grade yield, A- line mark, TTV, wire breakage rate and maximum torque were tested, wherein:

[0187] (1) A+ grade yield

[0188] A+ grade yield refers to the proportion of silicon wafers whose quality fully meets factory standards to the total number of silicon wafers cut.

[0189] (2) A-line mark

[0190] A-Line marks refer to the ratio of the number of silicon wafers with line marks that do not affect the quality of subsequent processing to the total number of silicon wafers cut.

[0191] (3) TTV

[0192] The thickness of multiple silicon wafers obtained by testing cutting, TTV is the difference between the maximum thickness and the minimum thickness of the silicon wafer. The TTV of the silicon wafer is based on the five-point measurement method. The thickness variation of the same silicon wafer should be less than 15% of its nominal thickness. The number of silicon wafers with TTV exceeding this standard accounts for the percentage of the total number of silicon wafers cut.

[0193] (4) Disconnection rate

[0194] The wire breakage rate refers to the frequency of diamond wire breaking due to various reasons during the cutting process.

[0195] (5) Maximum torque

[0196] It refers to the torque applied to the bearing box during the silicon wafer cutting process.

[0197] Table 5

[0198]

[0199] It can be seen from the above data that the cutting fluids of Examples 1-4 have better lubricity than the cutting fluids of Comparative Examples 1-6, and have obvious advantages in A+ grade yield, maximum torque and wire breakage rate during the cutting process.

Claims

1. A polyetherester, characterized in that: It comprises the structural formula shown in Formula I: I Where R is C3-C 12 An alkyl group, a is an integer selected from 1-50, b is an integer selected from 1-50, c is an integer selected from 0-50, and d is an integer selected from 0-50; The molecular weight distribution index of the polyetherester is 1.02-1.

30.

2. The polyetherester according to claim 1, characterized in that The polyetherester satisfies one or more of the following conditions (1) to (7): (1) R is C5-C 12 An alkyl group such as hexyl, nonyl or dodecyl; (2) a is 3-20, such as 5, 10, 12 or 15; (3) b is 5-30, such as 6, 12, 13 or 15; (4) c is 5-30, such as 5, 11, 12 or 14; (5) d is 3-20, such as 4, 9, 11, 12 or 14; (6) The molecular weight distribution index of the polyetherester is 1.03-1.20, for example, 1.04, 1.13 or 1.18; (7) The weight average molecular weight of the polyetherester is selected from 300-10000, preferably 1000-5000, for example 1127, 2669 or 3196.

3. A method for preparing polyether ester, characterized in that: The method comprises the following steps: mixing an alkyl phosphate having 3 to 12 carbon atoms and a catalyst, introducing ethylene oxide, performing a first reaction, performing a first aging, and then introducing propylene oxide, performing a second reaction, and performing a second aging to obtain the polyether ester; The molar ratio of the ethylene oxide to the propylene oxide is (1-2):

1.

4. The method for preparing polyether ester according to claim 3, characterized in that: The preparation method of the polyether ester satisfies one or more of the following conditions (1) to (12): (1) The alkyl phosphate is an alkyl phosphate having 5 to 12 carbon atoms, such as one or more of hexyl phosphate, nonyl phosphate and dodecyl phosphate, such as hexyl phosphate, nonyl phosphate, dodecyl phosphate, or hexyl phosphate and dodecyl phosphate; (2) The type of the catalyst is one or more of potassium hydroxide, potassium methoxide, phosphazene series catalysts and dimethyl carbonate, such as potassium methoxide; (3) The molar ratio of the alkyl phosphate to the catalyst is (0.3-3):0.07, preferably (0.5-2.8):0.07, such as 2.74:0.07, 1.34:0.07 or 0.68:0.07; (4) The temperature of the first reaction is 140-160°C, preferably 142-150°C, for example 145°C; (5) The temperature of the first aging is 140-160°C, for example 150°C; (6) The first ripening time is 50-70 min, preferably 60 min; (7) The temperature of the second reaction is 130-150°C, preferably 132-140°C, for example 135°C; (8) The temperature of the second aging is 130-160°C, for example 135 or 145°C; (9) The second ripening time is 2-3 hours, for example 2.5 hours; (10) The molar ratio of the ethylene oxide to the propylene oxide is (1.05-1.25):1, such as 1.20:1, 1.08:1 or 1.00:1; (11) The molar ratio of the alkyl phosphate to the ethylene oxide is (20-100):1, preferably (22-95):1, such as 91.33:1, 32.68:1 or 23.45:1; (12) The molar ratio of the alkyl phosphate to the propylene oxide is (20-120):1, preferably (22-110):1, for example, 109.6:1, 35.26:1 or 23.45:

1.

5. A polyetherester, characterized in that: The polyether ester is prepared by the preparation method of the polyether ester as claimed in claim 3 or 4.

6. The polyetherester according to claim 5, characterized in that The polyether ester is one or more of hexyl phosphate polyoxyethylene ether polyoxypropylene ether, nonyl phosphate polyoxyethylene polyoxypropylene ether and dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, such as hexyl phosphate polyoxyethylene ether polyoxypropylene ether, nonyl phosphate polyoxyethylene polyoxypropylene ether, dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, or hexyl phosphate polyoxyethylene ether polyoxypropylene ether and dodecyl phosphate polyoxyethylene ether polyoxypropylene ether; Wherein, when the polyether ester is hexyl phosphate polyoxyethylene ether polyoxypropylene ether, the weight average molecular weight of the hexyl phosphate polyoxyethylene ether polyoxypropylene ether is preferably 1000-2000, for example 1127; Wherein, when the polyether ester is polyoxyethylene polyoxypropylene nonyl phosphate ether, the weight average molecular weight of the polyoxyethylene polyoxypropylene nonyl phosphate ether is preferably 2000-3000, for example, 2669; Wherein, when the polyether ester is dodecyl phosphate polyoxyethylene ether polyoxypropylene ether, the weight average molecular weight of the dodecyl phosphate polyoxyethylene ether polyoxypropylene ether is preferably 3000-4000, for example 3196.

7. A cutting fluid, characterized in that: It comprises the polyetherester as claimed in any one of claims 1 to 2 or claims 5 to 6.

8. The cutting fluid according to claim 7, characterized in that The cutting fluid comprises the following components, and the percentage is the percentage of the mass of each component to the total mass of the cutting fluid: 5-50% of the polyether ester according to any one of claims 1-2 or claims 5-6; Isomeric alcohol polyoxyethylene ether 10-30%; Defoaming agent 0.1-0.3%; Solvent 3-10%; pH adjuster 0.01-0.03% Water balance.

9. The cutting fluid according to claim 8, characterized in that The cutting fluid satisfies one or more of the following conditions (1)-(9): (1) The mass percentage of the polyether ester is 10-30%, such as 18%, 10% or 25%; (2) The isomeric alcohol polyoxyethylene ether is one or more of isooctyl alcohol polyoxyethylene ether polyoxypropylene ether, isononyl alcohol polyoxyethylene ether polyoxypropylene ether and isomeric tridecyl alcohol polyoxyethylene ether polyoxypropylene ether, for example, isooctyl alcohol polyoxyethylene ether polyoxypropylene ether and / or isononyl alcohol polyoxyethylene ether polyoxypropylene ether; (3) The mass percentage of the isomeric alcohol polyoxyethylene ether is 20-28%, for example, 22% or 23%; (4) The defoamer is an organosilicon defoamer; the type of the organosilicon defoamer is preferably one or more of BYK-012, BYK-016, BYK-024, BYK-018 and BYK-028, such as BYK-012, BYK-016 or BYK-018; (5) The mass percentage of the defoaming agent is 0.10-0.25%, for example, 0.15% or 0.20%; (6) The type of the solvent is one or more of dipropylene glycol, isopropyl alcohol, isohexylene glycol and ethylene glycol monobutyl ether, for example, isohexylene glycol, isopropyl alcohol, ethylene glycol monobutyl ether, or isohexylene glycol and isopropyl alcohol; (7) The mass percentage of the solvent is 5.0-9.0%, for example 6.0% or 8.0%; (8) The pH regulator adjusts the pH of the system to 6-7, preferably triethanolamine; (9) The mass percentage of the pH adjuster is 0.015-0.025%, for example 0.02%.

10. Use of the polyetherester according to any one of claims 1 to 2 or claims 5 to 6 or the cutting fluid according to any one of claims 7 to 9 in the preparation of silicon wafers.

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