Aldehyde-modified silicone oil, preparation method and application

Abstract

The invention discloses a kind of aldehyde-modified silicone oil, preparation method and application, belong to organosilicon-modified silicone oil technical field.Its technical scheme is:1) alkenal, end hydrogen-containing silicone oil are weighed and added into reactor, catalyst is added at a certain temperature, N2 is passed through, heating and stirring reaction, obtains aldehyde-modified silicone oil crude product;2) catalyst is quenched using 1 ethynylcyclohexanol, low-boiling-point substance is removed by vacuum distillation, and aldehyde-modified silicone oil is obtained. The silicone oil prepared by the present invention is novel in structure, and aldehyde group is introduced into silicone oil for the first time, and process is simple, and there is no technical problem such as complex process, high cost etc. The silicone oil can be cross-linked with diethylenetriamine, and can be used to prepare hydrophobic coating, with good hydrophobic effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of organosilicon-modified silicone oil, and in particular relates to an aldehyde-modified silicone oil, a preparation method and application thereof. Background Art

[0002] Modified silicone oil refers to products in which the methyl groups on the silicone oil molecular chain are replaced with organic groups or functional polymer segments, thereby changing the original properties of the silicone oil. Modified silicone oil inherits the advantages of ordinary silicone oil, such as aging resistance, mold release, high and low temperature resistance, and physiological inertness, while also possessing a series of properties not found in ordinary silicone oil, such as easy emulsification, adsorption, biocompatibility, and wettability. The performance and applications of modified silicone oil vary depending on the functional groups introduced. Common modified silicone oils include amino-modified silicone oil, polyether-modified silicone oil, epoxy-modified silicone oil, phenyl silicone oil, and vinyl silicone oil. The invention patent with publication number CN117327282A discloses a method for preparing amino-modified silicone oil, comprising: (1) mixing an amine compound, acetic acid, and propionic acid, and reacting them at a certain temperature for a certain time to obtain a modified ammonium salt; (2) mixing 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane with the modified ammonium salt, and reacting them at a certain temperature for a certain time to obtain an aminosiloxane intermediate; and (3) mixing octamethylcyclotetrasiloxane, a catalyst, and the aminosiloxane intermediate, and reacting them at a certain temperature for a certain time to obtain an amino-modified silicone oil. The target product prepared by this preparation method has a controllable structure, does not involve solvent in the reaction, has good wettability and stability, and has high reaction production efficiency. Patent publication number CN115368574A discloses a modified silicone oil, preparation method, and application. Hydrogenated polysiloxane is modified with alkyl-terminated allyl polyether, unterminated allyl polyether, and aromatic allyl ether to produce the modified silicone oil shown in Formula 1. This modified silicone oil can effectively control the surface, internal pore structure, and dimensional stability of one-component polyurethane foam, providing a new approach to the synthesis of organosilicon surfactants for one-component polyurethane foam sealants. Furthermore, the preparation method is simple and easy to operate, making it suitable for industrial production. However, the amino- and ether-modified silicone oils described above have certain limitations in their application.

[0003] Aldehyde groups are highly reactive and structurally active chemical groups with extensive applications in fields such as organic synthesis, biochemistry, and materials science. The amine-aldehyde condensation reaction is a key chemical reaction, primarily involving the reaction between a carbonyl-containing aldehyde or ketone and an amino-containing compound (such as an amine). This reaction requires simple conditions and can proceed at room temperature. Introducing aldehyde groups into silicone oils can bring new properties and functions to silicone oils, necessitating the development of aldehyde-modified silicone oils. Summary of the Invention

[0004] The present invention provides an aldehyde-modified silicone oil, a preparation method and an application thereof. Aldehyde groups are selectively introduced into silicone oil through a hydrosilylation reaction to obtain aldehyde-modified silicone oil. The aldehyde-modified silicone oil is cross-linked and cured with a diamine compound through an amine-aldehyde reaction, and can be used to prepare a hydrophobic coating.

[0005] The technical solution of the present invention is:

[0006] In a first aspect, a method for preparing an aldehyde-modified silicone oil is disclosed, comprising the following steps:

[0007] 1) Add olefinic aldehyde and terminal hydrogen-containing silicone oil to a reactor, raise the temperature to 50-70°C, add a catalyst, introduce N2, raise the temperature to 70-120°C, stir and react for 3-10 hours to obtain a crude aldehyde silicone oil;

[0008] 2) The crude product obtained in step 1) is quenched with 1-ethynylcyclohexanol to remove the catalyst, and low-boiling substances are removed by distillation under reduced pressure to obtain aldehyde-modified silicone oil.

[0009] Preferably, the alkenal is selected from one of 10-undecenal, 8-undecenal, 9-undecenal, 2-undecenal, decenal, octenal, acrolein, 4-pentenal, 2-pentenal, 7-octenal, 9-decenal, 3-pentenal, isopentenal, isobutylenealdehyde, 2-butenal, 2-hexenal, 2-decenal, 8-nonenal, 2-dodecenal, 8-undecenal, 2-propylacrolein, 4-hexenal, 2-benzylacrolein, 2-ethylacrolein, 2-heptenal, 2-decenal, 7-decenal, 4-decenal, 2-nonenal, 6-nonenal, and 5-octenal.

[0010] Preferably, the terminal hydrogen-containing silicone oil is a low-end hydrogen-containing silicone oil, and the hydrogen content in the terminal hydrogen-containing silicone oil is selected from one of 0.01-0.015%, 0.04-0.05%, 0.06-0.08%, 0.1-0.12%, 0.11-0.13%, and 0.17-0.19%.

[0011] Preferably, in step 1), the molar ratio of olefinic aldehyde to terminal hydrogen-containing silicone oil is (1.05-1.3):1.

[0012] Preferably, the amount of catalyst used in step 1) is 5ppm-20ppm of the total mass of olefinic aldehyde and terminal hydrogen-containing silicone oil.

[0013] Preferably, the amount of 1-ethynylcyclohexanol used in step 2) is 1 / 30-1 / 20 of the mass of the catalyst, more preferably 1 / 25.

[0014] Preferably, the catalyst in step 1) is PT-5000YB catalyst produced by Guangzhou Siyou New Material Technology Co., Ltd.

[0015] In a second aspect, the aldehyde-modified silicone oil prepared by the preparation method of the aldehyde-modified silicone oil is disclosed.

[0016] In a third aspect, the invention discloses the use of the aldehyde-modified silicone oil in preparing a hydrophobic coating. The method for preparing the hydrophobic coating comprises the following steps:

[0017] S1 prepares ethyl acetate solutions of aldehyde-modified silicone oil and diethylenetriamine respectively;

[0018] S2: spraying the ethyl acetate solution of aldehyde-modified silicone oil and the ethyl acetate solution of diethylenetriamine on the surface of the glass sheet in sequence, and placing it at 25-30° C. until the surface liquid solidifies to obtain the hydrophobic coating material.

[0019] Preferably, in step S1, the mass concentration of the aldehyde-modified silicone oil is 50-55%, and the mass concentration of diethylenetriamine is 50-55%.

[0020] First, different aldehyde segments are introduced into the end groups of hydrogenated silicone oil via a hydrosilylation reaction. These segments then undergo cross-linking and copolymerization with diamine compounds via an amine-aldehyde condensation reaction. After curing, a transparent, hydrophobic coating material with hydrophobic properties is obtained. As a low-surface-energy organosilicon material, the introduction of this coating reduces the surface free energy of the glass while increasing its surface roughness, thereby achieving a hydrophobic effect.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The silicone oil prepared in the present invention has good reactivity and can react with a diamine compound at room temperature to form a film to obtain a hydrophobic coating. The hydrophobic coating has good curing performance, is non-sticky after curing, and has a suitable curing time of 20-23 hours. The contact angle between the glass with the hydrophobic coating of the present invention and water can reach 114.8°, showing good hydrophobic properties.

[0023] 2. The aldehyde-modified silicone oil prepared by the present invention has a simple process and does not have technical problems such as complex process and high cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the infrared structure of the aldehyde-modified silicone oil prepared in Example 1 of the present invention.

[0025] Figure 2 Schematic diagram of the contact angle between the hydrophobic coating prepared in Example 1 of the present invention and glass.

[0026] Figure 3 Schematic diagram of the infrared structure of the aldehyde-modified silicone oil prepared in Comparative Example 1 of the present invention.

[0027] Figure 4Schematic diagram of the infrared structure of the aldehyde-modified silicone oil prepared in Comparative Example 2 of the present invention.

[0028] Figure 5 Schematic diagram of the contact angle between uncoated glass and water in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0030] The preparation method of 50% ethyl acetate solution of aldehyde-modified silicone oil and diethylenetriamine is as follows: weigh 20g of aldehyde-modified silicone oil and 20g of diethylenetriamine respectively and place them in a 100ml spray bottle, add 20g of ethyl acetate respectively, mix well and set aside.

[0031] Example 1

[0032] Weigh 4.64g (27.6mmol) of 10-undecenal and 40g (24mmol) of terminal hydrogenated silicone oil (hydrogen content 0.06-0.08%, purchased from Ningbo Runhe High-tech Materials Technology Co., Ltd.) and add them to the reactor. Heat to 70°C, add 0.0893g (10ppm in terms of platinum) of Karsted catalyst (PT-5000YB catalyst produced by Guangzhou Siyou New Materials Technology Co., Ltd.), introduce N2, heat to 90°C and stir to react for 5h to obtain crude aldehyde silicone oil. Add 0.0036g of 1-ethynylcyclohexanol to quench the catalyst. Remove low-boiling substances by reduced pressure distillation at 150°C under a vacuum degree of less than -0.95MPa. Wait until the mass no longer changes to obtain undecenal-modified silicone oil. The viscosity (25°C) is 74mPa·S. Figure 1 As shown in the figure, (a) is the infrared spectrum of the mid-range hydrogenated silicone oil in this embodiment, (b) is the infrared spectrum of the undecenal modified silicone oil prepared in this embodiment, 914cm -1 and 2123cm -1 Deformation and stretching vibrations of Si-H, 1726 cm -1 Attributable to -CHO, 1650cm -1 There is no absorption peak attributed to -C=C nearby. From the infrared spectra before and after the reaction, we can see that after the reaction, Si-H disappears, indicating that the reaction is complete, and -CHO appears, indicating that the reaction occurs and Si-H selectively adds to -C=C.

[0033] Preparation of hydrophobic coating:

[0034] Undecyl aldehyde modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared separately to form silicone oil solutions and diethylenetriamine solutions, which were placed in spray bottles respectively. The silicone oil solution was first sprayed evenly on a 50 mm × 50 mm glass, followed by the diethylenetriamine solution. The glass was placed at 25°C until the surface liquid was completely solidified, and a colorless transparent film was formed on the glass surface. The solidification time and the contact angle between water and the glass surface were recorded, as shown in Table 1. The contact angle between the glass with the hydrophobic coating and water is shown in Table 1. Figure 2 shown.

[0035] Example 2

[0036] 2.92 g (52 mmol) of acrolein and 40 g (40 mmol) of terminal hydrogenated silicone oil (hydrogen content 0.1-0.12%) were weighed and added to a reactor. The temperature was raised to 50°C, and 0.0858 g (10 ppm) of Karsted catalyst was added. N₂ was introduced, and the reaction was stirred at 70°C for 4 hours to obtain a crude aldehyde-based silicone oil. 0.0042 g of 1-ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing. This yielded acrolein-modified silicone oil with a viscosity of 50 mPa·s (25°C).

[0037] Preparation of hydrophobic coating:

[0038] A 50% ethyl acetate solution of acrolein-modified silicone oil and diethylenetriamine were prepared to form a silicone oil solution and a diethylenetriamine solution, respectively. The solutions were placed in spray bottles and evenly sprayed onto a 50 mm × 50 mm glass. The diethylenetriamine solution was then sprayed onto the glass. The glass was left at 25°C until the liquid on the surface completely solidified, forming a colorless, transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0039] Example 3

[0040] 2.96 g (19.2 mmol) of 9-decenal and 40 g (16 mmol) of hydrogenated silicone oil (hydrogen content 0.04-0.06%) were weighed and added to a reactor. The temperature was raised to 60°C, and 0.1289 g (15 ppm) of Karsted catalyst was added. N₂ was introduced, and the reaction was stirred at 100°C for 10 hours to obtain a crude aldehyde-based silicone oil. 0.0043 g of 1-ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing. 9-decenal-modified silicone oil was obtained. The viscosity (25°C) was 61 mPa·s.

[0041] Preparation of hydrophobic coating:

[0042] 9-decenal-modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and the silicone oil solution was first evenly sprayed on a 50 mm × 50 mm glass. The diethylenetriamine solution was then sprayed on the glass. The glass was left at 25°C until the liquid on the surface was completely solidified, forming a colorless transparent film on the glass surface. The solidification time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0043] Example 4

[0044] 0.84 g (5 mmol) of 2-undecenal and 40 g (4 mmol) of terminal hydrogenated silicone oil (hydrogen content 0.01-0.015%) were weighed and added to a reactor. The temperature was raised to 60°C, and 0.1634 g (20 ppm) of Karsted catalyst was added. N₂ was introduced, and the reaction was stirred at 120°C for 9 hours to obtain a crude aldehyde-based silicone oil. 0.0065 g of 1-ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing, yielding 2-undecenal-modified silicone oil. The viscosity (25°C) was 78 mPa·s.

[0045] Preparation of hydrophobic coating:

[0046] 2-Undecenal-modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and the silicone oil solution was first evenly sprayed on a 50 mm × 50 mm glass. The diethylenetriamine solution was then sprayed on the glass. The glass was left at 25°C until the liquid on the surface was completely solidified, forming a colorless transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0047] Example 5

[0048] 7.08 g (48.4 mmol) of 2-benzyl acrolein and 40 g (44 mmol) of hydrogenated silicone oil (hydrogen content 0.11-0.13%) were weighed and added to a reactor. The temperature was raised to 50°C, and 0.0942 g (10 ppm) of Karsted catalyst was added. N₂ was introduced, and the reaction was stirred at 110°C for 7 hours to obtain a crude aldehyde-based silicone oil. 0.0037 g of ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing. 2-benzyl acrolein-modified silicone oil was obtained. The viscosity (25°C) was 89 mPa·s.

[0049] Preparation of hydrophobic coating:

[0050] 2-Benzyl acrolein-modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and evenly sprayed onto a 50 mm × 50 mm glass sheet. The diethylenetriamine solution was then sprayed onto the glass sheet. The glass sheet was left at 25°C until the liquid on the surface completely solidified, forming a colorless, transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0051] Example 6

[0052] 6.01 g (71.4 mmol) of 2-ethylacrolein and 40 g (68 mmol) of terminal hydrogenated silicone oil (0.17-0.19%) were weighed and added to a reactor. The temperature was raised to 70°C, and 0.1380 g (15 ppm) of Karsted catalyst was added. N₂ was introduced, and the reaction was stirred at 80°C for 8 hours to obtain a crude aldehyde-based silicone oil. 0.0046 g of 1-ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing. 2-ethylacrolein-modified silicone oil was obtained. The viscosity (25°C) was 68 mPa·s.

[0053] Preparation of hydrophobic coating:

[0054] 2-Benzyl acrolein-modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and evenly sprayed onto a 50 mm × 50 mm glass sheet. The diethylenetriamine solution was then sprayed onto the glass sheet. The glass sheet was left at 25°C until the liquid on the surface completely solidified, forming a colorless, transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0055] Example 7

[0056] 1.85 g (26.4 mmol) of methacrolein and 40 g (24 mmol) of terminal hydrogenated silicone oil (0.06-0.08%) were weighed and added to a reactor. The temperature was raised to 60°C, and 0.0419 g (5 ppm) of Karsted catalyst was added. N₂ was introduced, and the temperature was raised to 90°C with stirring for 6 h to obtain a crude aldehyde-based silicone oil. 0.0021 g of 1-ethynylcyclohexanol was added to quench the catalyst. Low-boiling substances were removed by reduced pressure distillation at 150°C under a vacuum of less than -0.95 MPa until the mass stopped changing, yielding methacrolein-modified silicone oil. The viscosity (25°C) was 76 mPa·s.

[0057] Preparation of hydrophobic coating:

[0058] Isopropylamine-modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and the silicone oil solution was first evenly sprayed on a 50 mm × 50 mm glass. The diethylenetriamine solution was then sprayed on the glass. The glass was left at 25°C until the liquid on the surface was completely solidified, forming a colorless transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0059] Comparative Example 1

[0060] 4.04 g (24 mmol) of 10-undecenal and 40 g (24 mmol) of terminal hydrogenated silicone oil (hydrogen content 0.06-0.08%) were weighed and added to a reactor, the temperature was raised to 70° C., 0.0881 g (10 ppm, it should be noted that 10 ppm is one hundred thousandth of the mass of the added raw materials) of Karsted catalyst was added, N2 was introduced, the temperature was raised to 90° C. and stirred for 5 h, 0.0036 g of 1-ethynylcyclohexanol was added to quench the catalyst, and low-boiling substances were removed by reduced pressure distillation at 150° C. under a vacuum degree of less than -0.95 MPa. When the mass no longer changed, a modified silicone oil was obtained. Figure 3 As shown, 914cm -1 and 2123cm -1 The absorption peaks attributed to the deformation and stretching vibration of Si-H have not completely disappeared, indicating that the Si-H reaction is not complete.

[0061] Preparation of hydrophobic coating:

[0062] Modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared separately to form silicone oil solutions and diethylenetriamine solutions, which were placed in spray bottles respectively. The silicone oil solution was first sprayed evenly on a 50 mm × 50 mm glass, followed by the diethylenetriamine solution. The glass was left at 25°C until the surface liquid was completely solidified, forming a colorless transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0063] Comparative Example 2

[0064] 5.65 g (33.98 mmol) of 10-undecenal and 40 g (24 mmol) of terminal hydrogenated silicone oil (hydrogen content 0.06-0.08%) were weighed and added to a reactor. The temperature was raised to 70° C., 0.0913 g (10 ppm) of Karsted catalyst was added, N2 was introduced, and the temperature was raised to 90° C. with stirring for 5 h. Then, 0.0037 g of 1-ethynylcyclohexanol was added to quench the catalyst. The low-boiling substances were removed by reduced pressure distillation at 150° C. under a vacuum degree of less than -0.95 MPa. When the mass no longer changed, a modified silicone oil was obtained. Figure 4 As shown, 914cm-1 and 2123cm -1 The absorption peak attributed to Si-H disappears, 1645 cm -1 An absorption peak attributed to -C=C appears at , indicating that the Si-H reaction is complete but C=C is not completely consumed.

[0065] Preparation of hydrophobic coating:

[0066] Modified silicone oil and 50% ethyl acetate solutions of diethylenetriamine were prepared separately to form silicone oil solutions and diethylenetriamine solutions, which were placed in spray bottles respectively. The silicone oil solution was first sprayed evenly on a 50 mm × 50 mm glass, followed by the diethylenetriamine solution. The glass was left at 25°C until the surface liquid was completely solidified, forming a colorless transparent film on the glass surface. The curing time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0067] Comparative Example 3

[0068] The undecenal-modified silicone oil in Example 1 was replaced with 10-undecenal.

[0069] Preparation of hydrophobic coating:

[0070] 50% ethyl acetate solutions of 10-undecenal and diethylenetriamine were prepared to form silicone oil solutions and diethylenetriamine solutions, respectively. The solutions were placed in spray bottles and evenly sprayed onto a 50 mm × 50 mm glass sheet. The diethylenetriamine solution was then sprayed onto the glass sheet. The liquid on the glass sheet was allowed to solidify completely after being placed at 25°C, forming a colorless, transparent film on the glass surface. The solidification time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0071] Comparative Example 4

[0072] The undecenal-modified silicone oil in Example 1 was replaced with the hydrogen-terminated silicone oil with a hydrogen content of 0.06-0.08% in Example 1.

[0073] Preparation of hydrophobic coating:

[0074] 50% ethyl acetate solutions of end-hydrogenated silicone oil and diethylenetriamine were prepared separately to form silicone oil solutions and diethylenetriamine solutions, which were placed in spray bottles respectively. The silicone oil solution was first sprayed evenly on a 50 mm × 50 mm glass, followed by the diethylenetriamine solution. The glass was left at 25°C until the liquid on the surface was completely solidified, forming a colorless transparent film on the glass surface. The solidification time and the contact angle between water and the glass surface were recorded, as shown in Table 1.

[0075] Comparative Example 5

[0076] In this comparative example, the glass was not treated, and the contact angle between water and the glass surface was as shown in Table 1 and Figure 5 shown.

[0077] Comparative Example 6

[0078] 4.64 g (27.6 mmol) of 10-undecenal and 40 g (24 mmol) of terminal hydrogenated hydrocarbon (hydrogen content 0.06-0.08%) were added to a reactor. 0.0893 g (10 ppm based on platinum) of Karsted catalyst was added. N₂ was introduced, and the temperature was raised to 90°C with stirring for 5 hours. In this comparative example, the catalyst was added directly at room temperature without preheating the temperature. However, no reaction occurred upon further heating.

[0079] Comparative Example 7

[0080] The difference from Example 1 is that diethylenetriamine is replaced by ethylenediamine in this comparative example, and the other preparation methods and steps are the same as those in Example 1.

[0081] Table 1

[0082] Curing time / h contact angle Example 1 21 114.8° Example 2 20 95.5° Example 3 22 101.2° Example 4 21.5 102.5° Example 5 23 106.5° Example 6 21 89.5° Example 7 21.5 92.5° Comparative Example 1 30, sticky after curing 103.6° Comparative Example 2 35, sticky after curing 85.2° Comparative Example 3 Not solidified -- Comparative Example 4 Not solidified -- Comparative Example 5 -- 77.2° Comparative Example 6 -- -- Comparative Example 7 19 98.5°

[0083] The aldehyde-modified silicone oil prepared by the embodiment of the present invention 1-7 has good reactivity, can react with diethylenetriamine at room temperature to form a film, obtain hydrophobic coating, the coating has good curing properties, is not sticky after curing, and has a suitable curing time of 20-23h, the contact angle between the glass and water not treated in comparative example 5 is 77.2 °, with the contact angle range between 92.5 ° to 114.8 ° of the glass and water of the embodiment of the present invention 1-7 hydrophobic coating, showing good hydrophobicity. The feed ratio of end hydrogenated silicone oil and 10-undecenal is changed respectively in comparative example 1-2, the aldehyde-modified silicone oil obtained reacts incompletely, and the hydrophobic coating curing time of preparation is longer, and there is tackiness, and contact angle is less. Undecenal-modified silicone oil is replaced with 10-undecenal and end hydrogenated silicone oil respectively in comparative example 3-4, and the hydrophobic coating of preparation is not solidified. Diethylenetriamine is replaced with ethylenediamine in comparative example 7, although curing time is shortened, hydrophobicity declines.

[0084] Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions are intended to fall within the scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for preparing aldehyde-modified silicone oil, characterized in that: The following steps are involved: 1) Add olefinic aldehyde and terminal hydrogen silicone oil into the reactor, heat to 50-70°C, add catalyst, introduce N2, heat to 70-120°C and stir for 3-10 hours to obtain crude aldehyde silicone oil; 2) The crude product obtained in step 1) is quenched with 1-ethynylcyclohexanol to remove the catalyst, and low-boiling substances are removed by vacuum distillation to obtain aldehyde-modified silicone oil; The alkenal is selected from the group consisting of 10-undecenal, 8-undecenal, 9-undecenal, 2-undecenal, decenal, octenal, acrolein, 4-pentenal, 2-pentenal, 3-pentenal, isopentenal, isomethacrolein, 2-butenal, 2-hexenal, 8-nonenal, 2-dodecenal, 2-propylacrolein, 4-hexenal, 2-benzylacrolein, 2-ethylacrolein, 2-heptenal, 2-nonenal, and 6-nonenal; In step 1), the molar ratio of olefinic aldehyde to terminal hydrogen-containing silicone oil is (1.05-1.3):

1.

2. The method for preparing the aldehyde-modified silicone oil according to claim 1, wherein The alkenal is selected from one of 9-decenal, 2-decenal, 7-decenal, 4-decenal, 7-octenal and 5-octenal.

3. The method for preparing the aldehyde-modified silicone oil according to claim 1, wherein The terminal hydrogen-containing silicone oil is a low-end hydrogen-containing silicone oil, and the hydrogen content in the terminal hydrogen-containing silicone oil is selected from one of 0.01-0.015%, 0.04-0.05%, 0.06-0.08%, 0.1-0.12%, 0.11-0.13%, and 0.17-0.19%.

4. The method for preparing the aldehyde-modified silicone oil according to claim 1, wherein The amount of catalyst used in step 1) is 5ppm-20ppm based on the total mass of olefinic aldehyde and terminal hydrogen-containing silicone oil.

5. The method for preparing the aldehyde-modified silicone oil according to claim 1, wherein In step 2), the amount of 1-ethynylcyclohexanol used is 1 / 30-1 / 20 of the mass of the catalyst.

6. The method for preparing the aldehyde-modified silicone oil according to claim 1, wherein The catalyst in step 1) is PT-5000YB catalyst produced by Guangzhou Siyou New Material Technology Co., Ltd.

7. The aldehyde-modified silicone oil prepared by the method for preparing the aldehyde-modified silicone oil according to any one of claims 1 to 6.

8. Use of the aldehyde-modified silicone oil according to claim 7 in preparing a hydrophobic coating, characterized in that: The method for preparing a hydrophobic coating comprises the following steps: S1 prepares ethyl acetate solutions of aldehyde-modified silicone oil and diethylenetriamine respectively; S2: spraying the ethyl acetate solution of aldehyde-modified silicone oil and the ethyl acetate solution of diethylenetriamine on the surface of the glass sheet in sequence, and placing it at 25-30° C. until the surface liquid solidifies to obtain the hydrophobic coating material.

9. Use of the aldehyde-modified silicone oil according to claim 8 in preparing a hydrophobic coating, characterized in that: In step S1, the mass concentration of the aldehyde-modified silicone oil is 50-55%, and the mass concentration of diethylenetriamine is 50-55%.

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