Application of alkyl modified silane polymer in preparation of alkali-resistant material

Abstract

The invention provides an application of an alkyl modified silane polymer in preparation of an alkali-resistant material. The structural formula of the alkyl modified silane polymer is shown as a formula (I), n is 1 or 8 or 10 or 12 or 16, k is 8 or 10, and m is a positive integer in the range of 15-150. The alkyl modified silane polymer provided by the invention has relatively good stability in an alkaline environment (such as a 1% strong alkali environment), can be stored for a long time in the alkaline environment, and particularly has very good stability in a high-temperature strong alkali environment.

Description

Technical Field

[0001] The present invention relates to the field of functional materials, and more specifically, to application of an alkyl-modified silane polymer in the preparation of an alkali-resistant material. Background Art

[0002] Silane polymers are used in various industries due to their excellent performance. Generally, in a neutral environment, silane polymers can maintain their original performance for a long time. However, in some extreme cases, it is inevitable to encounter a strong alkaline environment, and sometimes even a high temperature and strong alkaline environment. In such extreme cases, the performance of conventional silane polymers will decrease or even decompose, thereby polluting the original process or environment. Summary of the invention

[0003] The first object of the present invention is to provide an application of an alkyl-modified silane polymer in the preparation of an alkali-resistant material. The alkyl-modified silane polymer provided by the present invention has good stability in an alkaline environment and can be stored for a long time in an alkaline environment. More preferably, it also has good stability in a high-temperature strong alkaline environment (for example, in a strong alkaline environment, the mass loss rate at 200°C / 12h is not higher than 5%).

[0004] The structural formula of the alkyl-modified silane polymer provided by the present invention is shown below (I):

[0005] (C n H 2n+1 )(CH3)2SiO[(C k H 2k+1 (CH3)SiO] m Si(CH3)2(C n H 2n+1 )

[0006] Formula (I),

[0007] Wherein, n is 1 or 8 or 10 or 12 or 16, k is 8 or 10, and m is a positive integer in the range of 15 to 150.

[0008] In a preferred embodiment of the present invention, m is 15. The research and development team of the present invention found that when m is 15, the alkyl-modified silane polymer having the structural formula has better alkali resistance. More preferably, n is 1, k is 8 or 10, and the mass loss rate of the alkyl-modified silane polymer having the structural formula is only 3% at 200°C / 12h in a strong alkaline environment.

[0009] In a preferred embodiment of the present invention, m is 15, n is 8, and k is 8. The mass loss rate of the alkyl-modified silane polymer under a strong alkaline environment at 200° C. / 12 h is only 3%.

[0010] The research team of the present invention has found that in addition to using the alkyl-modified silane polymer provided by the present invention alone to prepare alkali-resistant materials or simply physically mixing them to prepare alkali-resistant materials, it has also been found that the silicone grease prepared based on the alkyl-modified silane polymer provided by the present invention can maintain stable properties in a strong alkaline environment. The silicone grease can be prepared with the alkyl-modified silane polymer provided by the present invention and the ingredients commonly used in the art. In a preferred embodiment of the present invention, the method for preparing the alkali-resistant material includes mixing the alkyl-modified silane polymer, calcium carbonate, and octyltrimethoxysilane. Among them, the mass ratio of the alkyl-modified silane polymer, calcium carbonate, and octyltrimethoxysilane is preferably (260-270): 400:1.

[0011] In a specific embodiment of the present invention, in the preparation method, after the reaction is completed, the small molecule substances are removed and cooled to obtain the product. The step of removing the small molecule substances can be carried out at a vacuum degree of 2 kPa and 120°C.

[0012] Another object of the present invention is to provide an alkyl-modified silane polymer having the above structural formula (I).

[0013] Another object of the present invention is to provide a method for preparing the alkyl-modified silane polymer having the above structural formula (I), which is more environmentally friendly than the prior art.

[0014] The preparation method comprises the following steps:

[0015] The methyldimethoxysilane derivative and the methoxysilane derivative are mixed and hydrolyzed under acidic conditions. After the reaction is completed, the oil layer is taken out, washed with water until neutral, and after removing water, a super acid is added for condensation;

[0016] The methyldimethoxysilane derivative is octylmethyldimethoxysilane, decylmethyldimethoxysilane, dodecylmethyldimethoxysilane or hexadecyldimethylmethoxysilane;

[0017] The methoxysilane derivative is trimethylmethoxysilane, octyldimethylmethoxysilane, decyldimethylmethoxysilane, dodecyldimethylmethoxysilane or hexadecyldimethylmethoxysilane.

[0018] In the scheme of the present invention, the methoxysilane derivatives specifically refer to trimethylmethoxysilane, octyldimethylmethoxysilane, decyldimethylmethoxysilane, dodecyldimethylmethoxysilane or hexadecyldimethylmethoxysilane, and do not include other methoxysilane derivatives.

[0019] In a preferred embodiment of the present invention, the molar ratio of the methyldimethoxysilane derivative to the methoxysilane derivative is (7.5-75):1, preferably (7.5-10):1.

[0020] In a preferred embodiment of the present invention, the acidic condition is to add hydrochloric acid to the reaction system. The amount of hydrochloric acid added is 2 to 3 times the total amount of the methyldimethoxysilane derivative and the methoxysilane derivative. In a specific embodiment of the present invention, the temperature of the hydrolysis reaction is 50 to 60°C, the reaction time is 6 to 7 hours, and then the liquid is separated and the oil phase is washed with water until it is neutral.

[0021] In a preferred embodiment of the present invention, the superacid can be a superacid catalyst commonly used in the art, such as solid acid NHD580. The condensation reaction is usually carried out in the presence of nitrogen, that is, nitrogen can be introduced into the system after the superacid is added to carry out the condensation reaction. In a preferred embodiment of the present invention, the condensation reaction temperature is 120° C. and the time is 6 to 12 hours.

[0022] In a specific embodiment of the present invention, after the condensation reaction is completed, the catalyst superacid is filtered out and then the low boiling point is removed at 240°C to obtain the product.

[0023] In a preferred embodiment of the present invention, the methyldimethoxysilane derivative is preferably octylmethyldimethoxysilane. In the present invention, the methyldimethoxysilane derivative can be commercially available or homemade. In actual production, the preparation method of the methyldimethoxysilane derivative can preferably include the following steps: methyldichlorosilane and olefin are subjected to addition reaction, and then esterified with methanol to obtain the methyldimethoxysilane derivative; wherein the olefin is octene, decene, dodecene or hexadecene. wherein the molar ratio of methyldichlorosilane to olefin is 1:(1.1-1.5), and the molar ratio of methyldichlorosilane to methanol is 1:(1.5-2.5).

[0024] In a preferred embodiment of the present invention, the temperature of the addition reaction in the preparation method of the methyldimethoxysilane derivative is 60 to 150° C. (preferably 70 to 80° C.), and the time of the addition reaction is 2 to 8 hours. The catalyst used in the addition reaction is a catalyst commonly used in the art, such as a platinum catalyst, and the amount of the catalyst is a conventional amount in the art. The temperature of the esterification reaction can be 80 to 85° C.

[0025] In a preferred embodiment of the present invention, the methoxysilane derivative is preferably trimethylmethoxysilane or octyldimethylmethoxysilane. In the present invention, trimethylmethoxysilane or octyldimethylmethoxysilane can be commercially available or homemade. For example, trimethylmethoxysilane can be obtained by reacting trimethylchlorosilane with methanol. Octyldimethylmethoxysilane can be prepared by reacting dimethylchlorosilane with octene and then esterifying with methanol.

[0026] In one embodiment of the present invention, if in the actual process, the methyldimethoxysilane derivative and the methoxysilane derivative are both obtained by self-production, then the hydrogen chloride gas produced in the preparation method of the dimethoxysilane derivative and the preparation method of the methoxysilane derivative can be introduced into the chlorine circulation system to prepare trichlorosilane, thereby realizing the circulation of chlorine. At the same time, the methanol produced by the hydrolysis reaction of the methyldimethoxysilane derivative and the dimethylmethoxysilane derivative can be distilled and then continued as a raw material to participate in the preparation method of the methyldimethoxysilane derivative and the dimethylmethoxysilane derivative, thereby realizing the circulation of methanol.

[0027] The preparation method provided by the present invention realizes the recovery of hydrogen chloride gas and the reuse of methanol from raw materials to products in terms of process, is economical and environmentally friendly, and realizes economical mass production in industry.

[0028] The alkyl-modified silane polymer with a specific structural formula provided by the present invention has good stability in an alkaline environment (for example, in a 1% strong alkaline environment), can be stored for a long time in an alkaline environment, and more preferably has good stability (mass loss rate is not higher than 5%) in a high temperature (for example, 80°C and above, more preferably 150°C and above, more preferably 200°C, etc.) strong alkaline environment. At the same time, the silicone grease prepared by using the alkyl-modified silane polymer is mixed with a strong alkaline solution (for example, the ratio of silicone grease to strong alkaline solution is 1:2, and the strong alkaline solution is a saturated solution), and can remain smooth and crack-free for at least 12 hours at 80°C, preferably for 72 hours, and more preferably for 74 hours. The alkyl-modified silane polymer provided by the present invention is a very excellent alkali-resistant material, especially for preparing high-temperature alkali-resistant materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the H NMR spectrum of the silane polymer 1 in Example 5;

[0030] Figure 2 is the H NMR spectrum of the silane polymer 2 in Example 6;

[0031] Figure 3 This is the H NMR spectrum of the silane polymer 3 in Example 7. DETAILED DESCRIPTION

[0032] The following examples are used to further describe the specific embodiments of the present invention. The following examples are used to illustrate the present invention, but are not limited to the scope of the present invention. In the present invention, if there is no special explanation, "%" is mass percentage.

[0033] Example 1

[0034] Octylmethyldimethoxysilane (C8H 17 Preparation of CH3Si(OCH3)2)

[0035] 1) 224 kg of octene and 0.1 kg of 800 ppm of platinum catalyst were added to a reactor, nitrogen was passed through, and the mixture was activated at 50° C. for 1 h. Then 230 g of methyldichlorosilane was added dropwise through a dropping funnel, and the temperature was controlled to avoid temperature surge. After the addition was completed, the mixture was kept at 70° C. for 2 h, and then distilled at a reflux ratio of 2:1. After the top temperature was stable, the product was collected by medium distillation to obtain the final product octylmethyldichlorosilane.

[0036] 2) The mass ratio of octylmethyldichlorosilane and methanol obtained in step 1 is 3.5:1 by a metering pump, methanol enters a vaporizer, is rapidly vaporized and heated to 80° C., and then enters the bottom of a reaction tower, octylmethyldichlorosilane enters from the top of the reaction tower and is sprayed downward, and the two react by countercurrent contact, the main product produced during the reaction falls to the bottom of the reactor, and the by-product HC1 gas overflows from the top of the reaction tower, and HC1 is collected and enters a chlorine circulation system; after the main product falls to the bottom of the tower, it is transferred to a neutralization kettle, saturated sodium methoxide solution is added dropwise to the neutralization kettle for neutralization, and filtered to a pH value of 8 to obtain a crude product, which is distilled at a reflux ratio of 2:1, and after the top temperature is stabilized, the product is collected by intermediate distillation to finally obtain the target product octylmethyldimethoxysilane.

[0037] Example 2

[0038] Decylmethyldimethoxysilane (C 10 H 21 Preparation of CH3Si(OCH3)2)

[0039] 1) 280 kg of decene and 0.1 kg of 800 ppm of platinum catalyst were added to a reactor, nitrogen was passed through, and the mixture was activated at 50° C. for 1 h. Then 230 g of methyldichlorosilane was added dropwise through a dropping funnel, and the temperature was controlled to avoid temperature surge. After the addition was completed, the mixture was kept at 70° C. for 2 h, and then distilled at a reflux ratio of 2:1. After the top temperature was stable, the product was collected by medium distillation to obtain decylmethyldichlorosilane.

[0040] 2) The mass ratio of decylmethyldichlorosilane and methanol is adjusted to 3.9:1 by a metering pump, methanol enters a vaporizer, is rapidly vaporized and heated to 80° C., and then enters the bottom of a reaction tower, decylmethyldichlorosilane enters from the top of the reaction tower and is sprayed downward, and the two react by countercurrent contact, the main product produced during the reaction falls to the bottom of the reactor, and the by-product HCl gas overflows from the top of the reaction tower, and the HCl is collected and enters a chlorine circulation system; after the main product falls to the bottom of the tower, it is transferred to a neutralization kettle, saturated sodium methoxide solution is added dropwise to the neutralization kettle for neutralization to a pH value of 8, filtered to obtain a crude product, and distilled at a reflux ratio of 2:1, and after the top temperature is stabilized, the product is collected by intermediate distillation to finally obtain the target product decylmethyldimethoxysilane.

[0041] Example 3

[0042] Octyldimethylmethoxysilane (C8H 17 Preparation of (CH3)2SiOCH3)

[0043] 1) 112 kg of octene and 0.08 kg of 800 ppm of platinum catalyst were added to a reactor, nitrogen was passed through, and the mixture was activated at 30° C. for 1 h. Then 94.5 g of dimethylchlorosilane was added dropwise through a dropping funnel, and the temperature was controlled to avoid temperature surge. After the addition was completed, the mixture was kept at 40° C. for 2 h and then at 80° C. for 2 h. The mixture was then distilled at a reflux ratio of 2:1. After the top temperature was stable, the product was collected by intermediate distillation to obtain the final product, octyldimethylchlorosilane.

[0044] 2) The mass ratio of octyldimethylchlorosilane and methanol is adjusted to 6.4:1 by a metering pump, methanol enters a vaporizer, is rapidly vaporized and heated to 80°C, and then enters the bottom of a reaction tower, octyldimethylchlorosilane enters from the top of the reaction tower and is sprayed downward, and the two react by countercurrent contact, the main product produced during the reaction falls to the bottom of the reactor, and the by-product HCl gas overflows from the top of the reaction tower, and the HCl is collected and enters a chlorine circulation system; after the main product falls to the bottom of the tower, it is transferred to a neutralization kettle, saturated sodium methoxide solution is added dropwise to the neutralization kettle for neutralization to a pH value of 8, filtered to obtain a crude product, and distilled at a reflux ratio of 2:1, and after the top temperature is stabilized, the product is collected by intermediate distillation to finally obtain the target product octyldimethylmethoxysilane.

[0045] Example 4

[0046] Preparation of trimethylmethoxysilane (CH3)3SiOCH3

[0047] The trimethylchlorosilane and methanol are pumped into the bottom of the reaction tower at a mass ratio of 108.7kg:32kg through a metering pump and refluxed at 60°C for 2h. The by-product HCl gas overflows from the top of the reaction tower, and the HCl is collected and enters the chlorine circulation system; the main product is transferred to a neutralization kettle, and a saturated sodium methoxide solution is added dropwise to the neutralization kettle for neutralization to a pH value of 8, and filtered to obtain a crude product, which is distilled at a reflux ratio of 2:1. After the top temperature is stabilized, the product is collected by intermediate distillation to obtain the target product, trimethylmethoxysilane.

[0048] Example 5

[0049] Methyl terminated methyloctylsilane polymer ((CH3)3SiO[(C8H 17 )(CH3)SiO] 15 Preparation of Si(CH3)3)

[0050] 3.26 kg of octylmethyldimethoxysilane and 0.21 kg of trimethylmethoxysilane were added to the reactor and heated to 50 °C. Hydrochloric acid with a pH of 2 was slowly added dropwise into the reactor. After the addition was completed, the temperature was kept for 6 hours. Then, the temperature was raised programmatically to increase the degree of reaction and separate methanol. The crude methanol entered the methanol neutralization purification system. After purification, esterification was continued. After the top temperature reached 95°C, the collection was stopped. The lower layer of water was returned to the dropping tank to adjust the pH. The upper layer of liquid was washed with water until the pH was 7. After filtration, it was transferred to the condensation reactor. At 100°C and a negative pressure of 0.09MPa, water was removed for 2 hours. Then, 2% (system mass) of solid acid NHD580 was added. At a negative pressure of 0.09MPa and 120°C, nitrogen was passed through for condensation for 8 hours. After the condensation was completed, the solid acid was filtered to remove it. At a negative pressure of 0.095MPa and 240°C, low boiling was removed to obtain a methyl-terminated methyloctylsilane polymer (referred to as silane polymer 1). The nuclear magnetic hydrogen spectrum of this substance is shown in Figure 1 The NMR peak ratio is consistent with the designed polymer structure.

[0051] Example 6

[0052] Octyl-terminated methyloctylsilane polymer (C8H 17 (CH3)2SiO[(C8H 17 )(CH3)SiO] 15 Si(CH3)2C8H 17 )

[0053] 3.26 kg of octylmethyldimethoxysilane and 0.40 kg of octyldimethylmethoxysilane were added to the reactor and heated to 50 °C. Hydrochloric acid with a pH of 2 was slowly added dropwise into the reactor. After the addition was completed, the temperature was kept for 6 hours. Then, the temperature was raised programmatically to increase the degree of reaction and separate methanol. The crude methanol entered the methanol neutralization purification system. After purification, esterification was continued. After the top temperature reached 95°C, the collection was stopped. The lower layer of water was returned to the dropping tank to adjust the pH. The upper layer of liquid was washed with water until the pH was 7. After filtering, it was transferred to the condensation reactor. At 100°C and a negative pressure of 0.09MPa, water was removed for 2 hours. Then, 2% (system mass) of solid acid NHD580 was added. At a negative pressure of 0.09MPa and a temperature of 120°C, nitrogen was passed through for condensation for 8 hours. After the condensation was completed, the solid acid was filtered to remove it. At 240°C and a negative pressure of 0.095MPa, the low boiling point was removed to obtain an octyl-terminated methyloctylsilane polymer (referred to as silane polymer 2). The NMR hydrogen spectrum of this substance is shown in Figure 2 The NMR peak ratio is consistent with the designed polymer structure.

[0054] Example 7

[0055] Methyl terminated methyldecylsilane polymer ((CH3)3SiO[(C 10 H 21 )(CH3)SiO] 15 Preparation of Si(CH3)3)

[0056] 3.68 kg of decylmethyldimethoxysilane and 0.21 kg of trimethylmethoxysilane were added to the reactor and heated to 50 °C. Hydrochloric acid with a pH of 2 was slowly added dropwise into the reactor. After the addition was completed, the temperature was kept for 6 hours. Then, the temperature was raised programmatically to increase the degree of reaction and separate methanol. The crude methanol entered the methanol neutralization purification system. After purification, esterification was continued. After the top temperature reached 95°C, the collection was stopped. The lower layer of water was returned to the dropping tank to adjust the pH. The upper layer of liquid was washed with water until the pH was 7. After filtration, it was transferred to the condensation reactor. At 100°C and a negative pressure of 0.09MPa, water was removed for 2 hours. Then, 2% (system mass) of solid acid NHD580 was added. At a negative pressure of 0.09MPa and a temperature of 120°C, nitrogen was passed through the reactor for condensation for 8 hours. After the condensation was completed, the solid acid was filtered out and removed. At a negative pressure of 0.095MPa and 240°C, a low boiling point was removed to obtain a methyl-terminated methyldecylsilane polymer (referred to as silane polymer 3). The nuclear magnetic hydrogen spectrum of this substance is shown in Figure 3 The NMR peak ratio is consistent with the designed polymer structure.

[0057] Example 8

[0058] The silane polymer 1 obtained in Example 5 was mixed with 60 g of nano-calcium carbonate and 0.15 g of octyltrimethoxysilane at room temperature for 30 min, then small molecules were removed at 120° C. and a vacuum degree of 2 kPa for 2 h, and finally cooled to obtain silicone grease 1.

[0059] Example 9

[0060] The silane polymer 2 obtained in Example 6 was mixed with 60 g of nano-calcium carbonate and 0.15 g of octyltrimethoxysilane at room temperature for 30 min, then small molecules were removed at 120° C. and a vacuum degree of 2 kPa for 2 h, and finally cooled to obtain silicone grease 2.

[0061] Example 10

[0062] The silane polymer 3 obtained in Example 7 was mixed with 60 g of nano-calcium carbonate and 0.15 g of octyltrimethoxysilane at room temperature for 30 min, then small molecules were removed at 120° C. and a vacuum degree of 2 kPa for 2 h, and finally cooled to obtain silicone grease 3.

[0063] Comparative Example 1

[0064] 40 g of 100 cp dimethyl silicone oil was mixed with 60 g of nano calcium carbonate and 0.15 g of octyl trimethoxy silane at room temperature for 30 min, then small molecules were removed at 120° C. and a vacuum degree of 2 kPa for 2 h, and finally the mixture was cooled to obtain silicone grease 4.

[0065] The testing methods of various properties and parameters in the present invention are as follows:

[0066] The viscosity was determined at 25°C using a NDJ-79 viscometer.

[0067] Use a 50 ml standard specific gravity cup and an analytical balance to determine the density at 20°C, referring to standard GB / T 4472-2011.

[0068] Use ZC36 high insulation resistance tester to determine the resistance at 250V.

[0069] Flash point was determined using a Cleveland open cup flash point tester.

[0070] Silane polymer alkali resistance test steps: Take 50g of the silane polymer of Examples 5 to 7 respectively, add them into a beaker, add 0.5g of potassium hydroxide, age at 200°C for 12h, calculate the mass retention rate by the difference method, record the data, and the results are shown in Table 2.

[0071] Silicone oil is a liquid, and there is a risk of alkaline substances falling into the silicone oil during use. Octyl silicone oil has better alkaline resistance than general silicone oil. Silicone grease is prepared with silicone oil as the base. The surface of silicone grease usually contacts alkaline substances, so in the specific implementation of the present invention, the following steps are used to test the alkaline resistance of the obtained silicone grease:

[0072] Silicone grease alkali resistance test steps: add 50g silicone grease (silicone grease obtained in Examples 8 to 10 and Comparative Example 1) to the bottom of a beaker, then add 100g saturated potassium hydroxide aqueous solution to the beaker, temperature 80°C, aging test, and observe the status, as shown in Table 3.

[0073] The NMR spectra were measured using Bruker Avance NEO 600 and deuterated chloroform as solvent.

[0074] The properties of the silane polymers obtained in Examples 5 to 7 are shown in Table 1.

[0075] Table 1 Properties of silane polymers

[0076] Silane polymer 1 Silane polymer 2 Silane polymer 3 Viscosity / 25℃mpa.s 60 64 69 <![CDATA[Density / g / cm 3 > 0.90 0.89 0.88 Volume resistivity Ω.CM <![CDATA[1.5*10 15 ]]> <![CDATA[5.3*10 15 ]]> <![CDATA[2.8*10 15 ]]> Flash point℃ 271 244 261

[0077] Table 2 Alkali resistance of silane polymers

[0078]

[0079] Table 3 Alkaline water resistance of silicone grease

[0080]

[0081] Finally, the method of the present invention is only a preferred embodiment and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An application of an alkyl-modified silane polymer in the preparation of an alkali-resistant material, characterized in that: The structural formula of the alkyl-modified silane polymer is shown below (I): (C n H 2n+1 )(CH3)2SiO[(C k H 2k+1 (CH3)SiO] m Si(CH3)2(C n H 2n+1 ) Formula (I), Wherein, n is 1 or 8 or 10 or 12 or 16, k is 8 or 10, and m is a positive integer in the range of 15 to 150.

2. The use according to claim 1, characterized in that: The m is 15.

3. The use according to claim 2, characterized in that: The n is 1, and k is 8 or 10.

4. The use according to claim 2, characterized in that: The n is 8 and the k is 8.

5. The use according to any one of claims 1 to 4, characterized in that The preparation method of the alkali-resistant material comprises the steps of mixing the alkyl-modified silane polymer, calcium carbonate and octyltrimethoxysilane, removing impurities and cooling.

6. The use according to claim 5, characterized in that: The mass ratio of the alkyl-modified silane polymer, calcium carbonate and octyltrimethoxysilane is (260-270):400:

1.

7. The use according to any one of claims 1 to 6, characterized in that The mass loss rate of the alkali-resistant material at 200° C. for 12 hours is no more than 3%.

8. A method for preparing an alkyl-modified silane polymer having a structural formula as shown in formula (I), characterized in that: The steps include: The methyldimethoxysilane derivative and the methoxysilane derivative are mixed and hydrolyzed under acidic conditions. After the reaction is completed, the oil layer is taken out, washed with water until neutral, and after removing water, a super acid is added for condensation; The methyldimethoxysilane derivative is octylmethyldimethoxysilane, decylmethyldimethoxysilane, dodecylmethyldimethoxysilane or hexadecyldimethylmethoxysilane; The methoxysilane derivative is trimethylmethoxysilane, octyldimethylmethoxysilane, decyldimethylmethoxysilane, dodecyldimethylmethoxysilane or hexadecyldimethylmethoxysilane.

9. The preparation method according to claim 8, characterized in that: The molar ratio of the methyldimethoxysilane derivative to the methoxysilane derivative is (7.5-75):

1.

10. The preparation method according to claim 8, characterized in that: The hydrolysis temperature is 50-60° C. and the time is 6-7 hours.

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