Amphiphilic modified silane coupling agent as well as preparation method and application thereof

Abstract

The invention provides an amphiphilic modified silane coupling agent as well as a preparation method and application thereof, and belongs to the field of material chemistry. The invention provides an amphiphilic modified silane coupling agent preparation method, which comprises: in the presence of an acid-binding agent and a first solvent, carrying out a reaction on a hydroxyl-containing hydrophilic polymer and halogenated acyl halide to obtain an ATRP initiator; in the presence of a metal salt catalyst, a ligand and a second solvent, reacting an ATRP initiator with an acrylate monomer to obtain an active macromolecule containing an amphiphilic group; in the presence of an alkali reagent and a third solvent, the active macromolecules containing the amphiphilic groups react with a silane compound containing amino groups, and the amphiphilic modified silane coupling agent is obtained. The silane coupling agent provided by the invention can be effectively applied to a coating, not only can improve the interface performance between an inorganic matter surface and an organic coating, but also can effectively improve the tensile strength, the waterproof and anti-fouling properties and the tensile strength after re-coating of a coating.

Description

Technical Field

[0001] The invention relates to the field of material chemistry, and in particular to an amphiphilic modified silane coupling agent, a preparation method and application thereof. Background Art

[0002] Silane coupling agents can react chemically on the surface of inorganic substances and organic substances at the same time. They are usually used to improve the interfacial adhesion between inorganic and organic materials, thereby increasing the bonding strength between materials. This is very important for improving the adhesion of coatings and the preparation of composite materials. Common silane coupling agents include vinyl coupling agents, chlorocarbon coupling agents, epoxy coupling agents, etc., which are widely used in many industrial fields such as coatings, adhesives, sealants, rubber products, plastic products, etc. Zhang Xiang et al. synthesized a silane coupling agent with the molecular formula (CH3O)2(CH3)Si(CH2) in patent CN115073755A. 10 The macromolecular silane coupling agent CH2OOCCH(CH2)(CH3) and the like were selected to prepare the solution with less pollution. The macromolecular silane coupling agent prepared by the method was added to the porcelain-resin and then subjected to aging treatment, and the bonding strength was significantly improved. Cong Weiwei et al. provided a silane coupling agent containing a fluorine-containing amphiphilic chain segment in patent CN107434843A, which has a significant inhibitory effect on biofilm and provides a basis for the realization of non-toxic antifouling, but did not consider the coating and labor costs learned during its use and maintenance.

[0003] The amphiphilic segment can make the target modified material obtain both hydrophilic and lipophilic groups. The principle is to graft or copolymerize the hydrophilic segment and the lipophilic segment into the target modified material in sequence to obtain a dendritic or star-shaped block copolymer. By adjusting the type and ratio of the hydrophilic segment and the lipophilic segment, the polymer, coating or modified material can be amphiphilically modified, and then the antifouling property, recoatability, hydrophilicity and compatibility with water-based coatings can be actively adjusted. Liu Min et al. combined ATRP and Click methods to synthesize a μ-(PEG45-b-PS25-b-PIPSMA25) star-shaped arm triblock copolymer with amphiphilicity for the first time in "Amphiphilic Block Copolymer Modified Nanosilica Particles and Their Applications". The modified nanosilica was used in the stabilization of Pickering emulsions and found to have a great improvement in the stability of the emulsion. In "Synthesis of Amphiphilic Block Copolymers and the Effect of the Mass Ratio of Hydrophilic and Hydrophobic Segments on the Self-Assembly Morphology", Liu Zhu et al. successfully synthesized the amphiphilic block copolymer PAA41-b-PMAEFcn using the ATRP polymerization method, and explored the effect of the mass ratio of hydrophilic segments to lipophilic segments on the self-assembly of polymers in water.

[0004] At present, the main method of amphiphilic chain segment modification is to copolymerize or polymerize the hydrophilic group and the lipophilic group separately and then connect them, and then graft the obtained product to the silane coupling agent. B Jiang et al. used sebacic acid and polyethylene glycol in toluene solution to prepare an amphiphilic low-molecular-weight polyester with a molecular weight of 600 in "Synthesis and characterization of nanocomposites from amphipathy polyester grafted modified sericite and methylsilicone resin". Dang Jingya et al. used LiAlH4, endometrium tetrahydrophthalic anhydride and CHCl3 to prepare the reaction monomers in "Synthesis and self-assembly of high-density amphipathic grafted polymer brushes" and successfully polymerized a polymer containing amphipathic chain segments.

[0005] However, the amphiphilic silane coupling agents in the prior art generally have the problems of being hydrophobic, difficult to re-coat the anti-fouling coating, and poor adhesion of the re-coated coating. Summary of the invention

[0006] The present invention is made to solve the above-mentioned problems, and its purpose is to provide an amphiphilic modified silane coupling agent, a preparation method and its application which has good compatibility in water, can improve the hydrophobicity, water resistance and antifouling properties of the coating, reduce the surface energy of the coating, provide hydrophilic anchoring points, and effectively improve the recoatability of the coating.

[0007] The present invention provides a method for preparing an amphiphilic modified silane coupling agent, which has the following characteristics and comprises the following steps:

[0008] Step 1, in the presence of an acid-binding agent and a first solvent, a hydrophilic polymer containing a hydroxyl group reacts with a halogenated acyl halide to obtain an ATRP initiator;

[0009] Step 2, in the presence of a metal salt catalyst, a ligand and a second solvent, the ATRP initiator reacts with an acrylate monomer to obtain an active macromolecule containing an amphiphilic group;

[0010] Step 3: in the presence of an alkali reagent and a third solvent, the active macromolecule containing an amphiphilic group reacts with a silane compound containing an amino group to obtain an amphiphilic modified silane coupling agent.

[0011] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein the hydrophilic polymer containing hydroxyl groups is selected from any one or more of polyethylene glycol, polyethylene glycol monomethyl ether, polypropylene glycol, and polypropylene glycol monobutyl ether.

[0012] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, in step 1, the molar ratio of the hydrophilic polymer containing hydroxyl group, the halogenated acyl halide and the acid binding agent is 1:(0.25-3):(0.2-5), preferably 1:(0.5-2):(0.5-2).

[0013] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, in step 1, the reaction time is 4-24h, such as 4h, 6h, 8h, 12h, 16h, 20h or 24h, and the stirring speed is 200-600rad / min.

[0014] The method for preparing the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein the acrylic ester monomer is selected from any one or more of n-butyl acrylate, tert-butyl acrylate, n-butyl methacrylate or tert-butyl methacrylate.

[0015] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, in step 2, the molar ratio of the ATRP initiator, the acrylate monomer, the metal salt catalyst and the ligand is 1:(0.2-5):(0.2-5):(0.6-1.8), preferably 1:(0.5-2):(0.5-2):(0.8-1.2).

[0016] In the preparation method of the amphiphilic modified silane coupling agent provided by the present invention, it can also have the following characteristics: wherein, in step 2, the reaction temperature is 80-150°C, such as 80°C, 90°C, 110°C, 130°C, 150°C, the reaction time is 1-8h, such as 1h, 1.5h, 2h, 3h, 4h, 5h, and the stirring speed is 200-600rad / min.

[0017] In the preparation method of the amphiphilic modified silane coupling agent provided by the present invention, it can also have the following characteristics: wherein the silane compound containing an amino group is selected from γ-aminopropyltriethoxysilane (cas number: 919-30-2, model KH550, structural formula NH2(CH2)3Si(OC2H5)3), N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (cas number: 1760-24-3, model KH792, structural formula NH2(CH2)2NH(CH2)3Si(OCH3)3), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (cas number: 3069-29-2, model KH602, structural formula NH2(CH2)2NH(C H2)3SiCH3(OCH3)2), γ-methacryloxypropyltrimethoxysilane (cas number: 2530-85-0, model KH570, structural formula CH2C(CH3)COO(CH2)3Si(OCH3)3), γ-methacryloxypropylmethyldimethoxysilane (cas number: 14513-34-9, model KH572, structural formula CH2C(CH3)COO(CH2)3Si(OCH3)2CH3), 3-(acryloxy)propyltrimethoxysilane (cas number: 4369-14-6, model KH5750, structural formula CH2CHCOO(CH2)3Si(OCH3)3) any one or more.

[0018] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, in step 3, the molar ratio of the active macromolecule containing an amphiphilic group, the silane compound containing an amino group and the alkaline reagent is (1-2): (1-10): (1-10), preferably 1: (2-5): (2-5).

[0019] The preparation method of the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, in step 3, the reaction temperature is 60-150° C., the reaction time is 6-24 h, such as 6 h, 8 h, 10 h, 12 h, 15 h, and the stirring speed is 200-600 rad / min.

[0020] The method for preparing the amphiphilic modified silane coupling agent provided by the present invention may also have the following characteristics: wherein, the method comprises the following steps:

[0021] Step 1, dissolving a hydrophilic polymer containing a hydroxyl group in a first solvent, adding a halogenated acyl halide and an acid binding agent in an ice-water bath, and reacting for 6-10 hours in an ice-water bath under the protection of an inert gas to obtain an ATRP initiator;

[0022] Step 2, dissolving the ATRP initiator in a second solvent, adding an acrylate monomer, freezing and then thawing, adding a metal salt catalyst and a ligand, heating to 110-150° C. under inert gas protection for 2-5 hours, and post-treating to obtain an active macromolecule containing an amphiphilic group;

[0023] Step 3, mixing the active macromolecule containing an amphiphilic group, the silane compound containing an amino group, the third solvent and the alkaline reagent, heating to 90-110° C. for reaction for 18-36 hours, and post-treating to obtain an amphiphilic modified silane coupling agent.

[0024] The present invention also provides an amphiphilic modified silane coupling agent having the following characteristics:

[0026] In the above formula, n:m=(1-5):(1-5), 7≤n≤90. Preferably, the amphiphilic modified silane coupling agent is prepared by the preparation method of the amphiphilic modified silane coupling agent described above.

[0027] The present invention also provides an application of an amphiphilic modified silane coupling agent in a coating, which has the following characteristics: the coating comprises:

[0028] 70-80 parts by weight of hydroxy acrylic resin, 20-25 parts of isocyanate curing agent, 0.2-1 parts of the amphiphilic modified silane coupling agent according to claim 9, 0.3-0.7 parts of dispersant, 0.3-0.7 parts of defoaming agent, and 0.4-0.8 parts of leveling agent.

[0029] Functions and Effects of the Invention

[0030] According to the amphiphilic modified silane coupling agent and the preparation method thereof involved in the present invention, a new silane coupling agent having amphiphilic macromolecular segments is prepared by selecting a hydrophilic polymer containing hydroxyl groups to provide a hydrophilic group segment and an acrylate monomer to provide a hydrophobic segment. Therefore, the silane coupling agent provided by the present invention can be effectively used in coatings, which can not only improve the interface performance between the inorganic surface and the organic coating, but also effectively improve the tensile strength, waterproof and anti-fouling properties of the coating and the tensile strength after recoating. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the infrared spectrum of the ATRP initiator prepared in Example 1 of the present invention;

[0032] Figure 2 is the NMR spectrum of the active macromolecule containing amphiphilic groups prepared in Example 1 of the present invention;

[0033] Figure 3is the permeation gel chromatography of the active macromolecule containing amphiphilic groups prepared in Example 1 of the present invention;

[0034] Figure 4 is the infrared spectrum of the amphiphilic modified silane coupling agent prepared in Example 1 of the present invention;

[0035] Figure 5 1 and 2 are graphs showing the results of the water resistance test in Test Example 2 of the present invention, wherein (a) is a graph showing the results of the water resistance test of the coating prepared in Example 8, (b) is a graph showing the results of the water resistance test of the coating prepared in Comparative Example 1, and (c) is a graph showing the results of the water resistance test of the coating prepared in Comparative Example 2. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail below in conjunction with embodiments and drawings.

[0037] In the following examples, unless otherwise specified, all reagents and equipment are commercially available products.

[0038] In the following examples, the isocyanate curing agent used is Wuhan Shiquanxing S-208, the leveling agent is Shenzhu SN-4034, the wetting agent is Shenzhu SN-3704, and the defoaming agent is Ona F291.

[0039] <Example 1>

[0040] A kind of amphiphilic modified silane coupling agent

[0041] This embodiment provides an amphiphilic modified silane coupling agent and a preparation method thereof, and the reaction equation is as follows:

[0042]

[0043] The steps include:

[0044] Step 1, in a three-necked flask, 0.01 mol of polyethylene glycol monomethyl ether is used to prepare a 0.33 mol / L solution using dichloromethane, and 0.01 mol of triethylamine and 0.013 mol of 2-bromoisobutyryl bromide are slowly added under ice-water bath conditions, and after mixing and stirring evenly, the mixture is synthesized under an ice-water bath and nitrogen environment. After reacting for 8 hours, a white liquid is obtained, and the sample is extracted 3-5 times using a saturated sodium bicarbonate solution and deionized water, and a macromolecular ATRP initiator (A) containing a hydrophilic group is obtained after rotary evaporation;

[0045] The obtained macromolecular ATRP initiator (A) containing hydrophilic groups was subjected to Fourier infrared FTIR test, and the test results are as follows: Figure 1 shown.

[0046] like Figure 1 As shown, 1735cm -1 The stretching vibration absorption peak of C=O appeared; 1108cm -1 The stretching vibration absorption peak of COC appeared, and it can be observed that the ester group was successfully synthesized, indicating the successful synthesis of the target ATRP initiator (A).

[0047] Step 2, add 0.005 mol of the above-mentioned ATRP initiator (A) and anisole into a three-necked flask to prepare a 0.05 mol / L solution of the ATRP initiator, and add 0.005 mol of butyl acrylate so that n:m=1:1 in the equation, mix and stir evenly, use liquid nitrogen to freeze and then cool and thaw, add 0.005 mol of cuprous bromide and slowly add 0.005 mol of pentamethyldiethylenetriamine, mix evenly and heat to 130° C. under a nitrogen environment, react for 3 hours, and obtain a dark yellow transparent liquid, use methanol and aqueous solution for coprecipitation and pass through a chromatography column, and obtain a yellow-brown viscous liquid after rotary evaporation, which is the macromolecular organic compound (B) containing an amphiphilic group;

[0048] The obtained macromolecular organic compound (B) containing amphiphilic groups was subjected to nuclear magnetic resonance hydrogen spectrum NMR-H test and gel permeation chromatography GPC test. The test results are as follows: Figure 2-3 shown.

[0049] like Figure 2 As shown, the absorption peak of O-CH2 is at 3.72ppm, and the absorption peak of CH2 is at 1.57ppm. Figure 3 The GPC number average molecular weight shown can be used to infer the successful polymerization of the macromolecular organic compound (B) containing amphiphilic groups.

[0050] Step 3, using anisole in a three-necked flask, 0.01 mol of the above-mentioned amphiphilic macromolecular organic matter (B) is prepared into a 0.5 mol / L solution, and 0.03 mol of sodium carbonate and 0.03 mol of γ-aminopropyltriethoxysilane (KH550) are added thereto, mixed evenly and heated to 100°C, reacted for 24 hours to obtain an orange-yellow solution, extracted with methanol aqueous solution and rotary evaporated to obtain a light yellow viscous liquid, which is the amphiphilic modified silane coupling agent (C).

[0051] The obtained amphiphilic modified silane coupling agent (C) was subjected to Fourier transform infrared FTIR test, and the test results are as follows: Figure 4 shown.

[0052] like Figure 4 As shown, we can observe 1454cm -1 It is the absorption peak of the secondary amino group -NH bending vibration; 1043cm -1 and 1097cm -1They are the in-plane bending vibration absorption peak of ether bond-COC- and the out-of-plane bending vibration absorption peak, 1724 cm -1 The peak of the stretching vibration of C=O indicates the successful synthesis of the target amphiphilic modified silane coupling agent (C).

[0053] <Example 2>

[0054] A kind of amphiphilic modified silane coupling agent

[0055] This embodiment provides an amphiphilic modified silane coupling agent and a preparation method thereof. The reaction equation is the same as that of the embodiment, and comprises the following steps:

[0056] Step 1, in a three-necked flask, 0.01 mol of polyethylene glycol monomethyl ether is used to prepare a 0.33 mol / L solution using dichloromethane, and 0.01 mol of triethylamine and 0.013 mol of 2-bromoisobutyryl bromide are slowly added under ice-water bath conditions, and after mixing and stirring evenly, the mixture is synthesized under an ice-water bath and nitrogen environment. After reacting for 8 hours, a white liquid is obtained, and the sample is extracted 3-5 times using a saturated sodium bicarbonate solution and deionized water, and a macromolecular ATRP initiator (A) containing a hydrophilic group is obtained after rotary evaporation;

[0057] Step 2, add 0.005 mol of the above-mentioned ATRP initiator (A) and anisole into a three-necked flask to prepare a 0.05 mol / L solution of the ATRP initiator, and add 0.01 mol of butyl acrylate so that n:m=1:2 in the equation, mix and stir evenly, use liquid nitrogen to freeze and then cool and thaw, add 0.005 mol of cuprous bromide and slowly add 0.005 mol of pentamethyldiethylenetriamine, mix evenly and heat to 130° C. under a nitrogen environment, react for 3 hours, and obtain a dark yellow transparent liquid, which is co-precipitated with methanol and aqueous solution and passed through a chromatography column to obtain a yellow-brown viscous liquid, which is a macromolecular organic compound (B) containing an amphiphilic group;

[0058] Step 3, using anisole in a three-necked flask, 0.01 mol of the above-mentioned amphiphilic macromolecular organic matter (B) is prepared into a 0.5 mol / L solution, and 0.03 mol of sodium carbonate and 0.03 mol of γ-aminopropyltriethoxysilane (KH550) are added thereto, mixed evenly and heated to 100°C, reacted for 24 hours to obtain an orange-yellow solution, extracted with methanol aqueous solution and rotary evaporated to obtain a light yellow viscous liquid, which is the amphiphilic modified silane coupling agent (C).

[0059] <Example 3>

[0060] A kind of amphiphilic modified silane coupling agent

[0061] This embodiment provides an amphiphilic modified silane coupling agent and a preparation method thereof. The reaction equation is the same as that of the embodiment, and comprises the following steps:

[0062] Step 1, in a three-necked flask, 0.01 mol of polyethylene glycol monomethyl ether is used to prepare a 0.33 mol / L solution using dichloromethane, and 0.01 mol of triethylamine and 0.013 mol of 2-bromoisobutyryl bromide are slowly added under ice-water bath conditions, and after mixing and stirring evenly, the mixture is synthesized under an ice-water bath and nitrogen environment. After reacting for 8 hours, a white liquid is obtained, and the sample is extracted 3-5 times using a saturated sodium bicarbonate solution and deionized water, and a macromolecular ATRP initiator (A) containing a hydrophilic group is obtained after rotary evaporation;

[0063] Step 2, add 0.01 mol of the above-mentioned ATRP initiator (A) and anisole into a three-necked flask to prepare a 0.05 mol / L solution of the ATRP initiator, and add 0.005 mol of butyl acrylate so that n:m=2:1 in the equation, mix and stir evenly, use liquid nitrogen to freeze and then cool and thaw, add 0.01 mol of cuprous bromide and slowly add 0.01 mol of pentamethyldiethylenetriamine, mix evenly and heat to 130° C. under a nitrogen environment, react for 3 hours, and obtain a dark yellow transparent liquid, co-precipitate with methanol and water solution and pass through a chromatography column, and then obtain a yellow-brown viscous liquid, which is a macromolecular organic compound (B) containing an amphiphilic group;

[0064] Step 3, using anisole in a three-necked flask, 0.01 mol of the above-mentioned amphiphilic macromolecular organic matter (B) is prepared into a 0.5 mol / L solution, and 0.03 mol of sodium carbonate and 0.03 mol of γ-aminopropyltriethoxysilane (KH550) are added thereto, mixed evenly and heated to 100°C, reacted for 24 hours to obtain an orange-yellow solution, extracted with methanol aqueous solution and rotary evaporated to obtain a light yellow viscous liquid, which is the amphiphilic modified silane coupling agent (C).

[0065] <Example 4>

[0066] A recoatable long-lasting low surface energy coating

[0067] This embodiment provides a method for preparing a recoatable long-lasting low surface energy coating, comprising the following steps:

[0068] Weigh 74.3 parts of hydroxy acrylic resin, 23.2 parts of isocyanate curing agent, 0.9 parts of amphiphilic modified macromolecular silane coupling agent prepared by the method in Example 1, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly to obtain the product.

[0069] <Example 5>

[0070] A recoatable long-lasting low surface energy coating

[0071] This embodiment provides a method for preparing a recoatable long-lasting low surface energy coating, comprising the following steps:

[0072] Weigh 74.5 parts of hydroxy acrylic resin, 23.3 parts of isocyanate curing agent, 0.6 parts of amphiphilic modified macromolecular silane coupling agent prepared by the method in Example 1, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly to obtain the product.

[0073] <Example 6>

[0074] A recoatable long-lasting low surface energy coating

[0075] This embodiment provides a method for preparing a recoatable long-lasting low surface energy coating, comprising the following steps:

[0076] Weigh 74.6 parts of hydroxy acrylic resin, 23.4 parts of isocyanate curing agent, 0.4 parts of amphiphilic modified macromolecular silane coupling agent prepared by the method in Example 1, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly to obtain.

[0077] <Example 7>

[0078] A recoatable long-lasting low surface energy coating

[0079] This embodiment provides a method for preparing a recoatable long-lasting low surface energy coating, comprising the following steps:

[0080] Weigh 74.3 parts of hydroxy acrylic resin, 23.2 parts of isocyanate curing agent, 0.9 parts of amphiphilic modified macromolecular silane coupling agent prepared by the method in Example 2, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly to obtain.

[0081] <Example 8>

[0082] A recoatable long-lasting low surface energy coating

[0083] This embodiment provides a method for preparing a recoatable long-lasting low surface energy coating, comprising the following steps:

[0084] Weigh 74.3 parts of hydroxy acrylic resin, 23.2 parts of isocyanate curing agent, 0.9 parts of amphiphilic modified macromolecular silane coupling agent prepared by the method in Example 3, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly to obtain.

[0085] <Comparative Example 1>

[0086] A coating

[0087] This comparative example provides a method for preparing a coating, comprising the following steps:

[0088] Weigh 75 parts of hydroxy acrylic resin, 23.4 parts of isocyanate curing agent, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly.

[0089] <Comparative Example 2>

[0090] A coating

[0091] This comparative example provides a method for preparing a coating, comprising the following steps:

[0092] Weigh 74.3 parts of hydroxy acrylic resin, 23.2 parts of isocyanate curing agent, 0.9 parts of aminosilane coupling agent KH550, 0.5 parts of wetting agent, 0.5 parts of defoaming agent, and 0.6 parts of leveling agent in parts by weight, put them into a mixer and mix them evenly.

[0093] <Test Example 1>

[0094] Water contact angle / adhesion test between new and old coatings

[0095] In this test example, the coatings provided in Examples 4-8 and Comparative Examples 1-2 were tested for water contact angle / adhesion between new and old coatings.

[0096] The test method for water contact angle is in accordance with the national standard "GB / T 30447-2013", using a contact angle tester to test the contact angle between the paint film and water.

[0097] The test method for adhesion between new and old coatings is in accordance with the national standard "GB / T 5210-2006", using a pull-off adhesion tester to test the adhesion between new and old coatings.

[0098] The test results are shown in Table 1.

[0099] Table 1 Water contact angle / adhesion test results between new and old coatings

[0100] Contact angle with water (degrees) Adhesion between new and old coatings (MPa) Example 4 124.3 10.42 Example 5 116.2 9.6 Example 6 107.0 8.97 Example 7 122.1 11.92 Example 8 126.7 10.17 Comparative Example 1 60.2 5.33 Comparative Example 2 63.4 13.72

[0101] As shown in Table 1, the amphiphilic modified silane coupling agent prepared in Examples 4-8 can effectively improve the hydrophobicity of the coating and also has good adhesion after recoating.

[0102] <Test Example 2>

[0103] Water resistance test

[0104] In this test, the water resistance of the coatings provided in Example 8 and Comparative Examples 1-2 was tested. The test method was in accordance with the national standard "GB / T 1733-1993". The tinplate after the coating was cured was sealed with transparent tape, and its 2 / 3 position was placed under the deionized water surface. It was left to stand for 240 hours to observe whether it had defects such as bubbles, rust, shedding or discoloration.

[0105] The test results are shown in Table 2 and Figure 5 shown.

[0106] Table 2 Water resistance test results

[0107]

[0108] As shown in Table 2, Comparative Examples 1 and 2 performed better in water, while Example 8 did not significantly decrease its water resistance after the introduction of the amphiphilic group compared to Comparative Examples 1 and 2, and only slightly swelled, which recovered after 24 hours. This proves that the introduction of the amphiphilic group has no significant effect on its water resistance.

[0109] Functions and Effects of the Embodiments

[0110] According to the amphiphilic modified silane coupling agent and preparation method thereof involved in the above-mentioned embodiments, since a hydrophilic polymer containing hydroxyl groups is selected to provide a hydrophilic group segment and an acrylate monomer is selected to provide a hydrophobic segment, a new silane coupling agent having an amphiphilic macromolecular segment is prepared. Therefore, the silane coupling agent provided in the above-mentioned embodiments can be effectively used in coatings, which can not only improve the interface performance between the inorganic surface and the organic coating, but also effectively improve the adhesion strength, anti-fouling performance and adhesion strength after recoating of the coating, while effectively ensuring its waterproofness.

[0111] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A method for preparing an amphiphilic modified silane coupling agent, characterized in that: The steps include: Step 1, in the presence of an acid-binding agent and a first solvent, a hydrophilic polymer containing a hydroxyl group reacts with a halogenated acyl halide to obtain an ATRP initiator; Step 2, in the presence of a metal salt catalyst, a ligand and a second solvent, the ATRP initiator reacts with an acrylate monomer to obtain an active macromolecule containing an amphiphilic group; Step 3: in the presence of an alkali reagent and a third solvent, the active macromolecule containing an amphiphilic group reacts with a silane compound containing an amino group to obtain an amphiphilic modified silane coupling agent.

2. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, The hydrophilic polymer containing hydroxyl groups is selected from any one or more of polyethylene glycol, polyethylene glycol monomethyl ether, polypropylene glycol, and polypropylene glycol monobutyl ether.

3. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, In step 1, the molar ratio of the hydrophilic polymer containing hydroxyl group, the halogenated acyl halide and the acid binding agent is 1:(0.25-3):(0.2-5).

4. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, The acrylic acid ester monomer is selected from any one or more of n-butyl acrylate, tert-butyl acrylate, n-butyl methacrylate or tert-butyl methacrylate.

5. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, In step 2, the molar ratio of ATRP initiator, acrylate monomer, metal salt catalyst and ligand is 1:(0.2-5):(0.2-5):(0.6-1.8).

6. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, The amino group-containing silane compound is selected from any one or more of γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and 3-(acryloxy)propyltrimethoxysilane.

7. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: in, In step 3, the molar ratio of the active macromolecule containing an amphiphilic group, the silane compound containing an amino group and the alkaline reagent is (1-2): (1-10): (1-10).

8. The method for preparing the amphiphilic modified silane coupling agent according to claim 1, characterized in that: The steps include: Step 1, dissolving a hydrophilic polymer containing a hydroxyl group in a first solvent, adding a halogenated acyl halide and an acid binding agent in an ice-water bath, and reacting for 6-10 hours in an ice-water bath under the protection of an inert gas to obtain an ATRP initiator; Step 2, dissolving the ATRP initiator in a second solvent, adding an acrylate monomer, freezing and then thawing, adding a metal salt catalyst and a ligand, heating to 110-150° C. under inert gas protection for 2-5 hours, and post-treating to obtain an active macromolecule containing an amphiphilic group; Step 3, mixing the active macromolecule containing an amphiphilic group, the silane compound containing an amino group, the third solvent and the alkaline reagent, heating to 90-110° C. for reaction for 18-36 hours, and post-treating to obtain an amphiphilic modified silane coupling agent.

9. An amphiphilic modified silane coupling agent, characterized in that: The structural formula is as follows: ； In the above formula, n:m=(1-5):(1-5), 7≤n≤90.

10. Application of amphiphilic modified silane coupling agent in coating, characterized in that: The coating comprises: 70-80 parts by weight of hydroxy acrylic resin, 20-25 parts of isocyanate curing agent, 0.2-1 parts of the amphiphilic modified silane coupling agent according to claim 9, 0.3-0.7 parts of dispersant, 0.3-0.7 parts of defoaming agent, and 0.4-0.8 parts of leveling agent.

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