Water-based high-temperature-resistant silicon resin coating and preparation method thereof

Abstract

The invention provides a water-based high-temperature-resistant silicon resin coating and a preparation method thereof. The water-based high-temperature-resistant silicon resin coating comprises the following components in parts by mass: 35-60 parts of hydrophilic modified silicon resin, 5-15 parts of epoxy silica sol, 1-3 parts of an emulsifier, 1-6 parts of amino-terminated hyperbranched polyamide, 3-6 parts of an auxiliary agent and 40-60 parts of water. Wherein the hydrophilic modified silicon resin is obtained by reacting amino silicon oil, trifunctional epoxy resin, octa-amino POSS (Polyhedral Oligomeric Silsesquioxane) and epoxy polyether. The trifunctional epoxy resin is triglycidyl p-aminophenol. According to the invention, the hydrophilicity of the organic silicon resin is improved, the compatibility among the components is optimized, the stability, high temperature resistance, strength and other properties of the coating are effectively improved, the problems in the prior art are solved, and the application prospect is good.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a water-based high-temperature resistant silicone resin coating and a preparation method thereof. Background Art

[0002] Silicone resin has been widely used in coatings. With its excellent weather resistance, heat resistance and chemical stability, it has become a key component of high-performance coatings. Its Si-O bond structure gives the coating excellent thermal stability, with a heat resistance temperature of up to 250°C. It also has good UV resistance and is suitable for harsh environments such as aerospace, automobiles and building exteriors. Compounding silicone resin with acrylic resin, epoxy resin, etc. can also enhance the flexibility, wear resistance and antifouling properties of the coating, further expanding the use of silicone resin. Environmentally friendly water-based silicone resins with high performance and sustainability are more in line with the development trend of modern green coatings and have become the development direction of this field.

[0003] However, existing silicone resin-based coating products still have some shortcomings. For example, when the temperature is above 300-400℃, silicone resin will decompose, destroying the protective effect of the coating. In order to improve the high temperature resistance of the coating, heat-resistant fillers such as silica sol and metal oxides are usually added. However, the compatibility of inorganic fillers with organic resins is poor, and the high temperature resistance of the composite coating is difficult to reach the ideal level. At the same time, due to the influence of uneven distribution, the adhesion, toughness and weather resistance of the coating also decrease. In addition, the conventional epoxy resin compounded with silicone resin has poor heat resistance, and it is difficult to ensure the reliability of the coating under high temperature conditions. How to further optimize the comprehensive performance of water-based silicone resin coatings is the current research focus in this field.

[0004] In summary, it is urgent to develop a new technical solution to solve the deficiencies in the existing technology. Summary of the invention

[0005] The water-based high-temperature resistant silicone resin coating provided by the present invention is compounded with hydrophilic modified silicone resin, epoxy silica sol and other materials, which not only improves the hydrophilicity of the silicone resin, but also optimizes the compatibility between the various components, effectively improves the stability, high temperature resistance, strength and other properties of the coating, solves the problems existing in the prior art, and has good application prospects.

[0006] One object of the present invention is to provide a water-based high temperature resistant silicone resin coating, wherein the water-based high temperature resistant silicone resin coating comprises the following components in parts by weight:

[0007]

[0008]

[0009] in,

[0010] The hydrophilic modified silicone resin is obtained by reacting amino silicone oil, trifunctional epoxy resin, octa-amino POSS (cage-shaped polyhedral oligomeric silsesquioxane), and epoxy group polyether.

[0011] Further, the trifunctional epoxy resin is triglycidyl p-aminophenol.

[0012] Further, the epoxy group polyether is polyethylene glycol diglycidyl ether.

[0013] Further, the epoxidized silica sol is an oligomer of epoxy group silane coupling agent and a silica sol modified by tetraethyl orthosilicate.

[0014] Further, the average particle size of the silica sol is ≤0.2 μm.

[0015] Further, the amino-terminated hyperbranched polyamide is selected from one or more of HyPer N101, HyPer N102, and HyPer N103.

[0016] Further, the preparation method of the aqueous high-temperature resistant silicone resin coating comprises the following steps:

[0017] S1. Mix amino silicone oil and trifunctional epoxy resin, and conduct a heating reaction to obtain an intermediate product;

[0018] S2. Mix the intermediate product and octa-amino POSS, conduct a heating reaction, then add epoxy group polyether, and continue the reaction to obtain a hydrophilic modified silicone resin;

[0019] S3. Mix water, the hydrophilic modified silicone resin, and epoxidized silica sol, then add an emulsifier, stir, add amino-terminated hyperbranched polyamide and an auxiliary agent, and discharge to obtain the aqueous high-temperature resistant silicone resin coating.

[0020] Further, in step S1, the temperature of the heating reaction is 140 - 150 °C.

[0021] Further, in step S2, the temperature of the heating reaction is 40 - 90 °C.

[0022] The present invention has the following beneficial effects:

[0023] (1) The waterborne high-temperature resistant silicone resin coating of the present invention contains a hydrophilic modified silicone resin. This component first reacts amino silicone oil with trifunctional epoxy resin to introduce a large number of epoxy groups, then reacts with octaamino POSS through the epoxy groups, and finally reacts with amino-terminated polyether through amino groups to obtain the product. The hydrophilic modified silicone resin has a hydrophilic polyethylene glycol segment, which effectively improves the hydrophilicity of the resin and improves the stability of the coating emulsion. More importantly, POSS particles are introduced into the modified silicone resin, which can significantly improve the heat resistance, high-temperature resistance and mechanical strength of the resin. In addition, the present invention uses trifunctional epoxy resin to react with silicone oil. This kind of resin has the characteristics of high temperature resistance and high strength, and can crosslink the silicone oil to form a network structure. After the introduced epoxy groups further react with substances such as octaamino POSS, the final product has a stable and dense three-dimensional crosslinked structure, which improves the thermal stability while also enhancing the mechanical properties such as toughness and strength. The large number of active functional groups in the modified resin also greatly promotes the adhesion of the coating.

[0024] (2) The present invention also modifies the surface of silica sol with epoxy group silane coupling agent oligomer and tetraethyl orthosilicate. On the one hand, it improves the compatibility of silica sol particles with organic resin and can be more stably and uniformly dispersed in the emulsion. On the other hand, the functional group density of the silane coupling agent oligomer is larger, so that the surface of the modified silica sol particles has more epoxy groups, and thus can crosslink more fully with components such as organosilicon resin and amino-terminated polyamide, embedding the silica sol particles into the polymer network. Through the synergistic effect of organic and inorganic components, the comprehensive performance of the coating is enhanced. Detailed implementation mode

[0025] In order to more clearly illustrate the technical solutions of the present invention, the following examples are listed. The raw materials, reactions and post-treatment means appearing in the examples are all common raw materials on the market and technical means well-known to those skilled in the art, unless otherwise specified.

[0026] The terms "preferred", "preferably", "more preferably" and the like in the present invention refer to the embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0027] It should be understood that, except in any operating examples or otherwise indicated, all numbers representing the amounts of ingredients or otherwise used in the specification and claims should be understood to be modified in all instances by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and appended claims are approximations that vary depending upon the desired properties sought to be obtained by the present invention.

[0028] The emulsifier in the embodiment of the present invention is WL-92 emulsifier (purchased from Xinyi Synthetic Technology Co., Ltd.) and OP-10 (purchased from Aladdin) in a mass ratio of 4:1; the auxiliary agent is defoamer BYK-A530, cosolvent tripropylene glycol butyl ether, dispersant BYK-190 and promoter N-(2-hydroxy-4-nitrobenzene)-N',N'-dimethylurea in a mass ratio of 0.5:2.5:1:1.

[0029] The amino-terminated hyperbranched polyamide in the embodiment of the present invention was purchased from Wuhan Hyperbranched Resin Technology Co., Ltd., N102.

[0030] The preparation method of the epoxy silica sol in the embodiment of the present invention comprises the following steps:

[0031] Silica sol (purchased from Shandong Better New Materials, LS100), tetraethyl orthosilicate and epoxy silane coupling agent oligomer (purchased from Guangzhou Longkai Chemical, LK-560) in a mass ratio of 5:1:1 were mixed, stirred at 70°C for 5 hours, and filtered and dried to obtain epoxy silica sol.

[0032] Octaamino POSS in the examples of the present invention was purchased from Xi'an Qiyue Biological, CAS No. 150380-11-3.

[0033] The amino silicone oil in the embodiment of the present invention is Dow Corning OFX-8040A.

[0034] The polyethylene glycol diglycidyl ether in the examples of the present invention was purchased from Aladdin, with Mn≈1000.

[0035] The "parts" in the embodiments of the present invention refer to parts by mass.

[0036] Example 1

[0037] A water-based high temperature resistant silicone resin coating, comprising the following components in parts by weight:

[0038]

[0039]

[0040] The preparation method of the water-based high temperature resistant silicone resin coating comprises the following steps:

[0041] S1. Using acetone as solvent, amino silicone oil and triglycidyl p-aminophenol in a mass ratio of 2:1 were mixed, and reacted at 140° C. for 3 h to obtain an intermediate product;

[0042] S2. Add octa - amino POSS to the intermediate product, react at 75 °C for 3 h, then add polyethylene glycol diglycidyl ether, and react at 50 °C for 6 h under a nitrogen atmosphere. After removing the solvent and drying, a hydrophilic - modified silicone resin is obtained;

[0043] Among them, the mass ratio of triglycidyl - p - aminophenol, octa - amino POSS, and polyethylene glycol diglycidyl ether is 1:1.1:0.3;

[0044] S3. According to the above mass fractions, mix water, hydrophilic - modified silicone resin, and epoxy - functionalized silica sol, then add an emulsifier, stir, and then add amino - terminated hyperbranched polyamide and additives, and discharge to obtain the water - borne high - temperature - resistant silicone resin coating.

[0045] Example 2

[0046] A water - borne high - temperature - resistant silicone resin coating, the water - borne high - temperature - resistant silicone resin coating comprises the following components in mass fractions:

[0047]

[0048] The preparation method of the water - borne high - temperature - resistant silicone resin coating comprises the following steps:

[0049] S1. Using acetone as a solvent, mix amino - silicone oil and triglycidyl - p - aminophenol with a mass ratio of 2:1, and react at 140 °C for 3 h to obtain an intermediate product;

[0050] S2. Add octa - amino POSS to the intermediate product, react at 75 °C for 3 h, then add polyethylene glycol diglycidyl ether, and react at 50 °C for 6 h under a nitrogen atmosphere. After removing the solvent and drying, a hydrophilic - modified silicone resin is obtained;

[0051] Among them, the mass ratio of triglycidyl - p - aminophenol, octa - amino POSS, and polyethylene glycol diglycidyl ether is 1:1.1:0.3;

[0052] S3. According to the above mass fractions, mix water, hydrophilic - modified silicone resin, and epoxy - functionalized silica sol, then add an emulsifier, stir, and then add amino - terminated hyperbranched polyamide and additives, and discharge to obtain the water - borne high - temperature - resistant silicone resin coating.

[0053] Example 3

[0054] A water - borne high - temperature - resistant silicone resin coating, the water - borne high - temperature - resistant silicone resin coating comprises the following components in mass fractions:

[0055]

[0056] The preparation method of the water - borne high - temperature - resistant silicone resin coating comprises the following steps:

[0057] S1. Using acetone as the solvent, mix amino silicone oil and tris(2,3-epoxypropyl)-p-aminophenol at a mass ratio of 2:1, and react at 140 °C for 3 h to obtain an intermediate product;

[0058] S2. Add octa-amino POSS to the intermediate product, react at 75 °C for 3 h, then add polyethylene glycol diglycidyl ether, and react at 50 °C for 6 h under a nitrogen atmosphere. After removing the solvent and drying, a hydrophilic modified silicone resin is obtained;

[0059] Among them, the mass ratio of tris(2,3-epoxypropyl)-p-aminophenol, octa-amino POSS, and polyethylene glycol diglycidyl ether is 1:1.1:0.3;

[0060] S3. According to the above mass parts, mix water, hydrophilic modified silicone resin, and epoxy-functionalized silica sol, then add an emulsifier, stir, add amino-terminated hyperbranched polyamide and additives, and discharge to obtain the waterborne high-temperature resistant silicone resin coating.

[0061] Comparative Example 1

[0062] A silicone resin coating. The difference between this comparative example and Example 1 is that steps S1 and S2 are modified as follows: Mix amino silicone oil and polyethylene glycol diglycidyl ether at a mass ratio of 2:0.5, and react at 50 °C for 6 h under a nitrogen atmosphere to obtain a hydrophilic modified silicone resin; Other components and preparation methods are the same as those in Example 1.

[0063] Comparative Example 2

[0064] A silicone resin coating. The difference between this comparative example and Example 1 is that steps S1 and S2 are deleted, and the hydrophilic modified silicone resin is replaced with a mixture of amino silicone oil, E12 epoxy resin, and octa-amino POSS at a mass ratio of 2:1:1; And in the preparation method of epoxy-functionalized silica sol, replace the epoxy-functionalized silane oligomer and tetraethyl orthosilicate with epoxy-functionalized silane coupling agent KH-560; Other components and preparation methods are the same as those in Example 1.

[0065] Test Example

[0066] Test method:

[0067] Stability: Seal the samples prepared in Examples 1-3 and Comparative Examples 1-2 in transparent containers respectively, place them at a constant temperature of 40 °C for 60 days, take them out and restore to room temperature, and observe the sample morphology: No obvious precipitation or stratification is qualified, and obvious precipitation or stratification appears as unqualified.

[0068] Adhesion, impact strength, water impermeability, heat resistance (300 °C, 6 h): Test according to the standards of GB / T 9286-1998, GB / T1732-1993, GB / T 16777-2008, and GB / T 1735-1979.

[0069] The test results are shown in Table 1.

[0070] Table 1 Performance Test Results of Samples in Examples 1-3 and Comparative Examples 1-2

[0071]

[0072] According to the above experimental data, it can be concluded that the waterborne high-temperature resistant silicone resin coating prepared in the examples of the present invention has good long-term storage stability, strong adhesion, high impact strength, and strong high-temperature resistance, and has excellent comprehensive properties. In Comparative Examples 1-2, due to the replacement of the hydrophilic modified silicone resin and epoxidized silica sol, the resin cannot form a stable network cross-linked structure, and at the same time does not have groups with good thermal stability and high-temperature resistance. Therefore, the mechanical properties and high-temperature resistance are significantly reduced. Due to the reduction of active groups, the adhesion of Comparative Examples 1 and 2 also decreases significantly. In summary, the waterborne high-temperature resistant silicone resin coating of the present invention solves the problems and defects existing in the prior art, and has important significance for the development and progress of silicone resin coating products.

[0073] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0074] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An aqueous high-temperature resistant silicone resin coating, characterized in that, The waterborne high-temperature resistant silicone resin coating comprises the following components in parts by mass: Among them, The hydrophilic modified silicone resin is obtained by reacting amino silicone oil, trifunctional epoxy resin, octaamino POSS and epoxy polyether.

2. The waterborne high-temperature resistant silicone resin coating according to claim 1, wherein, The trifunctional epoxy resin is triglycidyl p-aminophenol.

3. The waterborne high-temperature resistant silicone resin coating according to claim 1, wherein The epoxy polyether is polyethylene glycol diglycidyl ether.

4. The waterborne high-temperature resistant silicone resin coating according to claim 1, characterized in that, The epoxidized silica sol is an oligomer of epoxy group silane coupling agent and silica sol modified by tetraethyl orthosilicate.

5. The waterborne high-temperature resistant silicone resin coating according to claim 1, wherein The terminal amino hyperbranched polyamide is selected from one or more of HyPer N101, HyPer N102, and HyPer N103.

6. The waterborne high-temperature resistant silicone resin coating according to claim 1, characterized in that, The preparation method of the waterborne high-temperature resistant silicone resin coating comprises the following steps: S1. Mix amino silicone oil and trifunctional epoxy resin, and carry out a heating reaction to obtain an intermediate product; S2. Mix the intermediate product and octaamino POSS, carry out a heating reaction, then add epoxy polyether, and continue the reaction to obtain a hydrophilic modified silicone resin; S3. Mix water, hydrophilic modified silicone resin, and epoxidized silica sol, then add an emulsifier, stir, add terminal amino hyperbranched polyamide and an auxiliary agent, and discharge to obtain the waterborne high-temperature resistant silicone resin coating.

7. The waterborne high-temperature resistant silicone resin coating according to claim 6, wherein, In step S1, the temperature of the heating reaction is 140-150 °C.

8. The waterborne high-temperature resistant silicone resin coating according to claim 6, characterized in that, In step S2, the temperature of the heating reaction is 40-90 °C.

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