Acrylic acid modified polysiloxane resin and preparation method thereof

Abstract

The invention relates to the technical field of polysiloxane resin, in particular to acrylic acid modified polysiloxane resin and a preparation method thereof. The coating comprises the following components in parts by weight: 100 parts of acrylic resin, 2-10 parts of a silane coupling agent, 30-70 parts of a methyl phenyl organosilicon oligomer and 0.1-1 part of a catalyst, the silane coupling agent is prepared from at least one of phenyl triethoxy silane, propyl triethoxy silane, gamma-aminopropyl triethoxy silane, and gamma-mercaptopropyl triethoxy silane. The silane coupling agent is prepared from at least one of phenyl triethoxy silane, propyl triethoxy silane, gamma-aminopropyl triethoxy silane and gamma-mercaptopropyl triethoxy silane. The prepared product is low in viscosity, high in solid content and suitable for preparing high-solid low-viscosity paint, VOC of the paint is reduced, and the product is more environmentally friendly; the alkali resistance and the aging resistance of the prepared coating are obviously improved compared with those of acrylic resin and polysiloxane resin products.

Description

Technical Field

[0001] The present invention relates to the technical field of polysiloxane resins, and specifically, to an acrylic-modified polysiloxane resin and a preparation method thereof. Background Art

[0002] Acrylic resins have characteristics such as light color, transparency, and corrosion resistance, while polysiloxanes have a Si-O bond as the main chain, endowing materials with high temperature resistance, weather resistance, water resistance, and chemical stability. Acrylic-modified polysiloxane resins are hybrid materials that combine acrylic resins and polysiloxanes through chemical grafting or composite technologies, possessing the excellent properties of both. Through modification technologies (such as glycidyl crosslinking, interpenetrating network structure, in-situ grafting, etc.), the compatibility of the two is improved, forming a synergistic effect. However, currently, acrylic-modified polysiloxane resins have problems such as poor yellowing resistance, acid and alkali resistance, and salt spray resistance.

[0003] Chinese invention patent CN106928410B relates to a modified resin prepared by copolymerizing an organosilicon macromonomer with an acrylate. The specific technology includes: synthesizing an organosilicon macromonomer with a hydroxyl-protecting group on the side chain and a silicon hydride group at one end, and then copolymerizing it with a methacrylate monomer to form a graft structure. The resin has a high solid content and low viscosity, is suitable for the coating field, and has excellent abrasion resistance, smoothness, and hydrophobicity. However, it does not involve the exploration of properties such as yellowing resistance, acid and alkali resistance, and salt spray resistance. Summary of the Invention

[0004] In the first aspect of the present invention, an acrylic-modified polysiloxane resin is provided. By weight, the components include: 100 parts of acrylic resin, 2 - 10 parts of silane coupling agent, 30 - 70 parts of methylphenyl organosilicon oligomer, and 0.1 - 1 part of catalyst; the silane coupling agent includes at least one of phenyltriethoxysilane, propyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltriethoxysilane.

[0005] Optionally, the silane coupling agent includes at least one of phenyltriethoxysilane and propyltriethoxysilane.

[0006] The addition amount of the silane coupling agent is 3 - 8 wt% of the acrylic resin.

[0007] Optionally, the addition amount of the silane coupling agent is 4 - 7 wt% of the acrylic resin.

[0008] The solid content of the acrylic resin is greater than 70 wt%, and the viscosity at 25°C is 2000 - 10000 mPa·s.

[0009] Optionally, the solid content of the acrylic resin is greater than 75 wt%, and the viscosity at 25°C is 2000 - 8000 mPa·s.

[0010] The weight ratio of the acrylic resin to the methylphenyl silicone oligomer is 1:(0.4 - 0.6).

[0011] Optionally, the weight ratio of the acrylic resin to the methylphenyl silicone oligomer is 1:(0.45 - 0.55).

[0012] The Ph / Me of the methylphenyl silicone oligomer is 0.1 - 10.

[0013] Optionally, the Ph / Me of the methylphenyl silicone oligomer is 0.5 - 3.

[0014] The viscosity of the methylphenyl silicone oligomer at 25 °C is 80 - 150 mm 2 / s.

[0015] Optionally, the viscosity of the methylphenyl silicone oligomer at 25 °C is 80 - 120 mm 2 / s.

[0016] The catalyst includes titanate catalysts.

[0017] Optionally, the titanate catalysts include at least one of tetrabutyl titanate, poly(tetrabutyl titanate), tetraisopropyl titanate, tetraethyl titanate, diisopropyl bis(ethyl acetoacetate) titanate, and tetra-tert-butyl titanate.

[0018] Optionally, the titanate catalysts include at least one of tetrabutyl titanate and poly(tetrabutyl titanate).

[0019] The research of the present invention finds that when the silane coupling agent is selected from at least one of phenyltriethoxysilane, propyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltriethoxysilane, the prepared coating has both yellowing resistance and acid and alkali resistance. It may be that ethoxysilane generates reactive silanol groups through hydrolysis, undergoes condensation or grafting reactions with the acrylic resin, forms chemical bonds and may introduce a crosslinked structure, thereby improving the weather resistance, mechanical properties and interfacial bonding ability of the resin. At the same time, the hydrolysis rate of ethoxy is moderate, avoiding excessive self-polymerization. While tetramethoxysilane lacks active groups and the methoxy hydrolysis is too fast, resulting in self-polymerization rather than effective crosslinking, and ultimately the coupling effect cannot be achieved.

[0020] The second aspect of the present invention provides a preparation method of an acrylic-modified polysiloxane resin, including the following steps:

[0021] S1, after uniformly mixing the acrylic resin and the catalyst, adding the silane coupling agent and heating for reaction to obtain a modified acrylic resin;

[0022] S2, adding the methylphenyl silicone oligomer to the modified acrylic resin and heating for reaction.

[0023] The temperature of the reaction in S1 is 95 - 110 °C, and the time is 2 - 5 h.

[0024] Optionally, the temperature of the reaction in S1 is 100 - 105 °C, and the time is 2 - 4 h.

[0025] The temperature of the reaction in S2 is 95 - 120 °C, and the time is 3 - 8 h.

[0026] Optionally, the temperature of the reaction in S2 is 105 - 115 °C, and the time is 4 - 6 h.

[0027] Beneficial effects

[0028] 1. The silane coupling agent is selected from at least one of phenyltriethoxysilane, propyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-mercaptopropyltriethoxysilane. The prepared coating has both yellowing resistance and acid and alkali resistance.

[0029] 2. The addition amount of the silane coupling agent is 3 - 8 wt% of the acrylic resin, and the solid content of the acrylic resin is greater than 70 wt%, and the viscosity at 25 °C is 2000 - 10000 mPa·s. It can improve the system compatibility while reducing the viscosity of the prepared resin and increasing the solid content.

[0030] 3. The weight ratio of the acrylic resin to the methylphenyl silicone oligomer is 1:(0.4 - 0.6), which can further improve the yellowing resistance of the resin. After 3000 h of artificial weathering test (HG / T 4755 - 2014), ΔE

[0031] <3.00.

[0032] 4. The temperature of the reaction in step S1 is 95 - 110 °C, and the time is 2 - 5 h. The resin can withstand the salt spray environment for 3000 h without abnormality.

[0033] 5. The viscosity of the methylphenyl silicone oligomer at 25 °C is 80 - 150 mm 2 / s. It can further improve the acid and alkali resistance of the resin (HG / T 4755 - 2014) and can withstand acids and alkalis for 10 days. Specific embodiments

[0034] Example 1

[0035] An acrylic modified polysiloxane resin, by weight, the components are: 100 parts of acrylic resin, 5 parts of silane coupling agent (phenyltriethoxysilane), 50 parts of methylphenyl silicone oligomer, and 0.2 part of catalyst (tetrabutyl titanate);

[0036] The solid content of the acrylic resin is 80 wt%, and its viscosity at 25 °C is 4000 - 8000 mPa·s. It is purchased from Huangshan Jinzhili Technology Co., Ltd., U8022C; the viscosity of the methylphenyl organosilicon oligomer at 25 °C is 100 mm 2 / s, and it is purchased from Shin-Etsu Chemical Co., Ltd. KR-510 of Japan.

[0037] A preparation method of an acrylic-modified polysiloxane resin comprises the following steps:

[0038] S1. After uniformly mixing the acrylic resin and the catalyst, add a silane coupling agent and heat for reaction to obtain a modified acrylic resin;

[0039] S2. Add the methylphenyl organosilicon oligomer to the modified acrylic resin and heat for reaction to obtain an acrylic-modified polysiloxane resin with a solid content of 85% and a viscosity of 1980 cps.

[0040] The reaction temperature in S1 is 100 °C and the time is 3 h; the reaction temperature in S2 is 110 °C and the time is 5 h.

[0041] Example 2

[0042] The specific implementation method is the same as that of Example 1; the difference is that the amount of the methylphenyl organosilicon oligomer in Example 2 is 60 parts, and an acrylic-modified polysiloxane resin with a solid content of 86% and a viscosity of 1700 cps is obtained.

[0043] Example 3

[0044] The specific implementation method is the same as that of Example 1; the difference is that the reaction conditions in S2 of Example 3 are changed to 115 °C and the time is 6 h, and an acrylic-modified polysiloxane resin with a solid content of 85.2% and a viscosity of 2100 cps is obtained.

[0045] Example 4

[0046] The specific implementation method is the same as that of Example 1; the difference is that the viscosity of the methylphenyl organosilicon oligomer at 25 °C in Example 4 is 120 mm 2 / s, and it is purchased from Wacker SILRES IC 232, and an acrylic-modified polysiloxane resin with a solid content of 84.8% and a viscosity of 2000 cps is obtained.

[0047] Comparative Example 1

[0048] The specific implementation method is the same as that of Example 1; the difference is that the silane coupling agent in Comparative Example 1 is methyl orthosilicate.

[0049] Comparative Example 2

[0050] The specific implementation manner is the same as that of Example 1; the difference is that the reaction temperature in S2 of Comparative Example 2 is 90 °C and the time is 2 h.

[0051] Performance test method

[0052] 1. Yellowing resistance performance:

[0053] Samples of Example 1 and Comparative Example 2 were made and tested according to the regulations in HG / T 4755-2014: artificial weathering test for 3000 h.

[0054] 2. Determination of acid and alkali resistance performance:

[0055] Samples of Example 1 and Comparative Example 2 were made and tested according to the regulations in HG / T 4755-2014.

[0056] 3. Salt spray test:

[0057] Samples of Example 1 and Comparative Example 2 were made and tested according to the regulations in HG / T 4755-2014: no abnormality after 3000 h.

[0058] The test data are listed in Table 1. Among them, no crosslinked product was obtained in Comparative Example 1, so no test was conducted and it is represented by " / ".

[0059] Performance test data

[0060] Table 1

[0061]

Claims

1. An acrylic-modified polysiloxane resin, characterized in that, By weight parts, the components include: 100 parts of acrylic resin, 2 - 10 parts of silane coupling agent, 30 - 70 parts of methylphenyl silicone oligomer, and 0.1 - 1 part of catalyst; the silane coupling agent includes at least one of phenyltriethoxysilane, propyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltriethoxysilane.

2. The acrylic acid-modified polysiloxane resin according to claim 1, wherein The addition amount of the silane coupling agent is 3 - 8 wt% of the acrylic resin.

3. The acrylic acid-modified polysiloxane resin according to claim 1, characterized in that, The solid content of the acrylic resin is greater than 70 wt%, and the viscosity at 25 °C is 2000 - 10000 mPa·s.

4. The acrylic-modified polysiloxane resin according to claim 1 or 3, characterized in that, The weight ratio of the acrylic resin to the methylphenyl silicone oligomer is 1:(0.4 - 0.6).

5. The acrylic-modified polysiloxane resin according to claim 1, characterized in that, The Ph / Me of the methylphenyl silicone oligomer is 0.1 - 10.

6. The acrylic acid modified polysiloxane resin according to claim 1, wherein The viscosity of the methylphenyl silicone oligomer is 80 - 150 mm 2 / s at 25°C.

7. The acrylic acid modified polysiloxane resin according to claim 1, characterized in that, The catalyst includes titanate catalysts.

8. A method for preparing the acrylic acid-modified polysiloxane resin according to any one of claims 1 to 7, characterized in that, It includes the following steps: S1, After mixing the acrylic resin and the catalyst evenly, add the silane coupling agent, and heat for reaction to obtain a modified acrylic resin; S2, Add the methylphenyl silicone oligomer to the modified acrylic resin and heat for reaction.

9. The preparation method of the acrylic acid modified polysiloxane resin according to claim 8, characterized in that, The The reaction temperature in S1 is 95 - 110 °C, and the time is 2 - 5 h.

10. The preparation method of the acrylic acid modified polysiloxane resin according to claim 8, characterized in that, The reaction temperature in S2 is 95 - 120 °C, and the time is 3 - 8 h.

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