Strong-adhesion and high-weather-resistance water-based fluorocarbon paint for GRPU base material, and preparation method therefor

Abstract

The present application relates to the technical field of water-based paint. Specifically disclosed are a strong-adhesion and high-weather-resistance water-based fluorocarbon paint for a GRPU base material, and a preparation method therefor. The strong-adhesion and high-weather-resistance water-based fluorocarbon paint for a GRPU base material comprises a component A and a component B, wherein the component A comprises the following components in parts by weight: 55-60 parts of a trifluoroether water-based fluorocarbon resin having a hydroxyl value of 60-70 mgK0H / g, 4-6 parts of a solvent, 7.3 parts of water, 1.5-2 parts of a dispersant, and 22-27 parts of a filler; and the component B comprises the following components in parts by weight: 40-60 parts of an organic silicon modified isocyanate tripolymer curing agent, 6-9 parts of a silane coupling agent, and 31-54 parts of a diluent. The water-based fluorocarbon paint in the present application can be used on a surface of a GRPU base material in a long-term water immersion environment, and has the advantages of high adhesive force and strong water resistance.

Description

Waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrate and its preparation method Technical Field

[0001] This application relates to the field of waterborne coatings technology, and more specifically, to a waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates and a method for preparing the same. Background Technology

[0002] GRPU, or glass fiber reinforced polyurethane, is a low-energy, environmentally friendly composite material primarily used in building materials industries such as doors and windows. The coatings used on the surface of GRPU substrates are divided into oil-based and water-based paints. Oil-based paints contain harmful substances such as benzene and formaldehyde, and have high VOC emissions, posing environmental pollution problems. Therefore, water-based paints are becoming increasingly widely used.

[0003] The preparation of GRPU substrate is mainly by pultrusion molding process. In order to maintain continuous pultrusion molding after in-mold molding, a release agent is added. Most of these release agents will adhere to the surface of GRPU substrate. The silicon component contained in the release agent makes the surface of the profile partially non-polar. At this time, the various interaction forces between the profile and the water-based paint film containing a large number of polar groups will decrease, making it difficult for the water-based paint to adhere to the GRPU substrate.

[0004] Currently, there is a two-component polyurethane coating for glass fiber reinforced polyurethane substrates, but its adhesion is low. Furthermore, because it uses hydrophilic modified hexamethylene diisocyanate containing hydrophilic groups as a curing agent, the coating has poor water resistance. Once the substrate is immersed in water for a long time, problems such as coating bubbling and peeling frequently occur, making it unsuitable for use in GRPU substrates in outdoor and indoor environments such as bathrooms where prolonged contact with water is possible. Summary of the Invention

[0005] In order to improve the adhesion of water-based paint on GRPU substrate surface after long-term immersion in water, this application provides a water-based fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrate and its preparation method.

[0006] In a first aspect, this application provides a water-based fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, employing the following technical solution:

[0007] A waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, comprising component A and component B;

[0008] Component A comprises the following components in parts by weight:

[0009] 55-60 parts of trifluoroether-based waterborne fluorocarbon resin with a hydroxyl value of 60-70 mg KOH / g;

[0010] Solvent 4-6 parts;

[0011] Water 7.3 parts;

[0012] Dispersant 1.5-2 parts;

[0013] 22-27 parts of filler;

[0014] Component B comprises the following components in parts by weight:

[0015] 40-60 parts of organosilicon-modified isocyanate trimer curing agent;

[0016] 6-9 parts of silane coupling agent;

[0017] Diluent 31-54 parts.

[0018] By adopting the above technical solution, a two-component room-temperature curing coating is formed using an alternating copolymer of trifluorochloroethylene and vinyl ether as the main film-forming substance and isocyanate. The fluorocarbon resin has a C-C bond as its main chain, and the fluorine atoms it contains have extremely high electronegativity and large atomic radii, resulting in strong interatomic forces between unbonded atoms. This allows the fluorine atoms to closely contact and cover the C-C bonds into a complete cylinder, providing a shielding protection for the C-C bonds. Furthermore, the FC bond energy (486 kJ / mol) formed between fluorine and carbon atoms is extremely high, much higher than that of CH bonds (410 kJ / mol), CO bonds (360 kJ / mol), C-C bonds (356 kJ / mol), and C-CI bonds (326 kJ / mol). In summary, the fluorocarbon paint of this application exhibits excellent weather resistance.

[0019] Simultaneously, a low-hydroxyl waterborne fluorocarbon resin is selected, which has a lower crosslinking density with the curing agent. The rigidity of the cured paint film decreases, making it easier to penetrate into the gaps on the substrate surface. This increases the area where the paint film anchors to the substrate, thus enhancing the mechanical bonding adhesion of the paint film. The inorganic end of the silane coupling agent hydrolyzes into silanol groups, which condense with the hydroxyl groups on the surface of the inorganic matrix to form covalent bonds. Meanwhile, the organic end forms a coupling with the organic matrix, thus forming a bond between the organic film-forming resin, the coupling agent, and the inorganic glass fiber. In summary, this improves the adhesion of the paint film to the GRPU substrate.

[0020] This organosilicon-modified isocyanate trimer curing agent contains polysiloxane organosilicon segments on one main chain of its trimer, exhibiting excellent hydrophobic properties. It reduces the hydrophilicity of sulfonates, resulting in a coating film with excellent water resistance after crosslinking and curing with waterborne fluorocarbon FEVE secondary dispersions. This solves the long-standing problem of poor water resistance in waterborne coatings used with GRPU in bathroom doors and windows.

[0021] Optionally, the trifluoroether-based waterborne fluorocarbon resin has a fluorine content of ≥13%.

[0022] By adopting the above technical solution, controlling the fluorine content to ≥13%, the coating film has a low coefficient of friction, thus improving wear resistance.

[0023] Optionally, the organosilicon-modified isocyanate trimer curing agent is Wanhua Aquolin 280 curing agent.

[0024] Optionally, the silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

[0025] By adopting the above technical solution, the inorganic end (-Si-OR3) in γ-glycidoxypropyltrimethoxysilane (YR-Si-OR3) is hydrolyzed into silanol (-Si-OH3). The silanol condenses with the hydroxyl groups on the surface of the inorganic matrix to form covalent bonds, while the organic end (-Y) couples with the organic matrix, forming a bond between the organic film-forming resin and the inorganic glass fiber. This improves the chemical bonding adhesion between the coating film and the GRPU substrate.

[0026] Optionally, the dispersant is a mixture of a nonionic polymeric dispersant and 2-hydroxy-4-methoxyacetophenone.

[0027] By employing the above technical solution, the nonionic polymeric dispersant disperses the filler through anchored steric hindrance, without undergoing charge-repulsive ionization. During the drying process of the paint film, the hydrophilic segments of the nonionic polymeric dispersant do not expand, thus having little impact on water resistance. Furthermore, the formulation with 2-hydroxy-4-methoxyacetophenone may enhance the dispersibility of the dispersant by increasing its steric hindrance or improving its adsorption to the filler surface, thereby improving the water resistance of the coating.

[0028] Optionally, the weight ratio of the nonionic polymeric dispersant to 2-hydroxy-4-methoxyacetophenone is 1:(0.3-0.5).

[0029] Optionally, the weight ratio of component A to component B is (5.8-6.2):1.

[0030] Secondly, this application provides a method for preparing a waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, using the following technical solution:

[0031] A method for preparing a waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates includes the following steps:

[0032] S1. Mix the dispersant and water, add the filler and stir to obtain a dispersion slurry; mix the trifluoroether-based waterborne fluorocarbon resin, solvent and dispersion slurry, stir and adjust the pH to 7.5-8.5 to obtain component A;

[0033] S2. Mix the diluent and silane coupling agent, add the isocyanate curing agent, and stir to obtain component B.

[0034] S3. Mix components A and B to obtain the final product.

[0035] By adopting the above technical solution, the process steps are fewer, the process is simple and efficient, which is conducive to the large-scale preparation of fluorocarbon paint. The adhesion of the prepared fluorocarbon paint on the surface of GRPU substrate can reach level one, the water resistance time can reach 380h, the performance is excellent, and it can be used on the surface of GRPU substrate in long-term water immersion environment.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. This application uses a trifluoroether-based waterborne fluorocarbon resin with a specific hydroxyl value, combined with a silane coupling agent and an organosilicon-modified curing agent, so that the adhesion of the prepared coating film on the GRPU substrate surface reaches level one and the water resistance reaches 320h, which can be used on the surface of GRPU substrate in long-term water immersion environment.

[0038] 2. This application uses specific silane coupling agents and dispersants to ensure that the coating film has superior adhesion and water resistance;

[0039] 3. The dispersant in this application is a mixture of nonionic polymeric dispersant and 2-hydroxy-4-methoxyacetophenone. 2-hydroxy-4-methoxyacetophenone enhances the dispersion effect of the nonionic dispersant on the filler, resulting in better water resistance of the paint film. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments. The water-based fluorocarbon paint of the present application is a two-component paint. Components A and B are stored separately and used together.

[0041] The components are sourced from the following sources, unless otherwise specified below:

[0042] The trifluoroether-based waterborne fluorocarbon resin, sourced from Shandong Jiaying Chemical Technology Co., Ltd., is model DF-03B, with a hydroxyl value of 60-70 mgKOH / g and a fluorine content of 13%.

[0043] Titanium dioxide, sourced from Longbai Group Co., Ltd., model R-996;

[0044] The organosilicon-modified isocyanate trimer curing agent was sourced from Wanhua Chemical Group Co., Ltd., model Aquolin 280. Example 1

[0045] A waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates is prepared by the following steps:

[0046] S1. Add 1.6 kg of nonionic polymeric dispersant (manufacturer: Zhanxin Resin, ADDITOL VXW 6208 / 60), 0.2 kg of defoamer (BYK-024), and 0.6 kg of rheology modifier (Guangdong Qirun New Materials Co., Ltd., QD06) to 7.3 kg of water, stir and mix well. While stirring at 600 rpm, add 25 kg of filler (titanium dioxide), and stir at 1500 rpm until the fineness is 15 μm to obtain a dispersion slurry.

[0047] 58 kg of trifluoroether-based waterborne fluorocarbon resin was added to a reactor, and stirring was started. While stirring at 500 rpm, 0.3 kg of wetting agent (Twin 4100 from Germany), defoamer (0.5 kg of SURFYNOL 104E from Germany, 0.2 kg of AGITAN 158 from Germany), 0.5 kg of BYK-3720, solvent (2 kg of ethylene glycol monobutyl ether, 3 kg of dipropylene glycol butyl ether), and the above dispersion were added sequentially. Stirring was continued for 30 min. Then, pH adjuster (N,N-dimethylethanolamine) and 0.6 kg of rheology modifier (QD06 from Guangdong Qirun New Materials Co., Ltd.) were added to adjust the pH to 8, thus obtaining component A.

[0048] S3. Add 8 kg of silane coupling agent (γ-glycidyl etheroxypropyltrimethoxysilane) to 42 kg of diluent (divalent ester), stir and mix well, while stirring, add 50 kg of organosilicon modified isocyanate trimer curing agent, stir and mix well to obtain component B.

[0049] S3. Mix component A and component B in a weight ratio of 6:1 to obtain the final product. Example 2

[0050] A waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, the components and their corresponding weights are shown in Table 1, and it is prepared by the following steps:

[0051] S1. Add 1.5 kg of nonionic polymeric dispersant (Zhanxin resin, ADDITOL VXW 6208 / 60), 0.2 kg of defoamer (BYK-024), and 0.4 kg of rheology modifier (Guangdong Qirun New Materials Co., Ltd., QD06) to 7.3 kg of water, stir and mix well. While stirring at 600 rpm, add 22 kg of filler (titanium dioxide), and stir at 1500 rpm until the fineness is 15 μm to obtain a dispersion slurry.

[0052] 55 kg of trifluoroether-based waterborne fluorocarbon resin was added to a reactor, and stirring was started. While stirring at 500 rpm, 0.2 kg of wetting agent (Twin 4100 from Germany), defoamer (0.3 kg of SURFYNOL 104E from Germany, 0.2 kg of AGITAN 158 from Germany), 0.3 kg of BYK-3720, solvent (2 kg of ethylene glycol monobutyl ether, 2 kg of dipropylene glycol butyl ether), and the above dispersion were added sequentially. Stirring was continued for 30 min. Then, pH adjuster (N,N-dimethylethanolamine) and 0.4 kg of rheology modifier (QD06 from Guangdong Qirun New Materials Co., Ltd.) were added to adjust the pH to 7.5, thus obtaining component A.

[0053] S3. Add 6 kg of silane coupling agent (γ-glycidyl etheroxypropyltrimethoxysilane) to 54 kg of diluent (divalent ester), stir and mix well, while stirring, add 40 kg of organosilicon modified isocyanate trimer curing agent, stir and mix well to obtain component B.

[0054] S3. Mix component A and component B at a weight ratio of 5.8:1 to obtain the final product. Example 3

[0055] A waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, the components and their corresponding weights are shown in Table 1, and it is prepared by the following steps:

[0056] S1. Add 2 kg of nonionic polymeric dispersant (Zhanxin resin, ADDITOL VXW 6208 / 60), 0.4 kg of defoamer (BYK-024), and 0.8 kg of rheology modifier (Guangdong Qirun New Materials Co., Ltd., QD06) to 7.3 kg of water, stir and mix well. While stirring at 600 rpm, add 27 kg of filler (titanium dioxide), and stir at 1500 rpm until the fineness is 15 μm to obtain a dispersion slurry.

[0057] 60 kg of trifluoroether-based waterborne fluorocarbon resin was added to a reactor, and stirring was started. While stirring at 500 rpm, 0.4 kg of wetting agent (Twin 4100 from Germany), defoamer (0.8 kg of SURFYNOL 104E from Germany, 0.4 kg of AGITAN 158 from Germany), 0.8 kg of BYK-3720, solvent (3 kg of ethylene glycol monobutyl ether, 3 kg of dipropylene glycol butyl ether), and the above dispersion were added sequentially. Stirring was continued for 30 min. Then, pH adjuster (N,N-dimethylethanolamine) and 0.8 kg of rheology modifier (QD06 from Guangdong Qirun New Materials Co., Ltd.) were added to adjust the pH to 8.5, thus obtaining component A.

[0058] S3. Add 9 kg of silane coupling agent (γ-glycidyl etheroxypropyltrimethoxysilane) to 31 kg of diluent (divalent ester), stir and mix well, while stirring, add 60 kg of organosilicon modified isocyanate trimer curing agent, stir and mix well to obtain component B.

[0059] S3. Mix component A and component B at a weight ratio of 6.2:1 to obtain the final product.

[0060] A waterborne fluorocarbon paint for GRPU substrates with strong adhesion and high weather resistance uses a different dispersant. Instead of ADDITOL VXW 6208 / 60, a mixture of nonionic polymeric dispersant (Zhanxin resin, ADDITOL VXW 6208 / 60) and 2-hydroxy-4-methoxyacetophenone in the following weight ratio is used:

[0061] Example 4: A mixture of ADDITOL VXW 6208 / 60 and 2-hydroxy-4-methoxyacetophenone in a weight ratio of 1:0.3.

[0062] Example 5: A mixture of ADDITOL VXW 6208 / 60 and 2-hydroxy-4-methoxyacetophenone in a weight ratio of 1:0.4.

[0063] Example 6: A mixture of ADDITOL VXW 6208 / 60 and 2-hydroxy-4-methoxyacetophenone in a weight ratio of 1:0.6.

[0064] Comparative Example 1: A water-based paint, differing from Example 1 in that an equal amount of water-based acrylate dispersion resin is used instead of trifluoroether-based water-based fluorocarbon resin, and an equal amount of Covestro Bayhydur 2655 curing agent is used instead of silicone-modified isocyanate trimer curing agent.

[0065] Comparative Example 2: A water-based fluorocarbon paint, which differs from Example 1 in that the amount of water-based fluorocarbon resin used is different, and the amount used is 50 kg.

[0066] Comparative Example 3: A water-based fluorocarbon paint, which differs from Example 1 in that the amount of water-based fluorocarbon resin used is different, and the amount used is 50 kg.

[0067] Comparative Example 4: A waterborne fluorocarbon paint, differing from Example 1 in that the hydroxyl value of the waterborne fluorocarbon resin is different. The waterborne fluorocarbon resin in this comparative example was purchased from Shanghai Deyude Trading Co., Ltd., brand name CX-802, with a hydroxyl value of 20-30 mg KOH / g and a fluorine content of 10%.

[0068] Comparative Example 5: A waterborne fluorocarbon paint, differing from Example 1 in that the hydroxyl value of the waterborne fluorocarbon resin is different. The waterborne fluorocarbon resin in this comparative example was purchased from Shandong Jiaying Chemical Technology Co., Ltd., model DF-M05, with a hydroxyl value of 70-90 mgKOH / g and a fluorine content >18%.

[0069] Comparative Example 6: A water-based fluorocarbon paint, which differs from Example 1 in that the use of isocyanate curing agent is different, and an equal amount of isoflurane diisocyanate is used instead of silicone-modified isocyanate trimer curing agent.

[0070] The coatings prepared in the examples and comparative examples were subjected to the following performance tests, and the test results are recorded in Table 1.

[0071] 1. Adhesion: Tested according to GB / T 9286-1998 "Cross-cut test for paint and varnish film". The test panel is made of glass fiber reinforced polyurethane substrate (i.e. GRPU substrate) with a thickness of 0.3mm. No surface oil removal is performed before use.

[0072] 2. Water resistance: Tested according to GB / T 1733-1993 "Test Method for Water Resistance of Paint Film", and the time when the coating on the test board surface begins to wrinkle is recorded. The longer the time, the better the water resistance.

[0073] Table 1 Performance Test Results

[0074] Project Adhesion Grade Water Resistance (h) Example 1 Grade 11 340 Example 2 Grade 11 330 Example 3 Grade 11 320 Example 4 Grade 11 380 Example 5 Grade 11 400 Example 6 Grade 11 390 Comparative Example 1 Grade 12 240 Comparative Example 22 Grade 230 Comparative Example 32 Grade 250 Comparative Example 4 Grade 11 200 Comparative Example 5 Grade 2 300 Comparative Example 6 Grade 22 280

[0075] Referring to the data in Table 1, in Examples 1-3, the use of trifluoroether-based waterborne fluorocarbon resins with specific hydroxyl values, combined with silane coupling agents and organosilicon-modified curing agents, resulted in coating films with Grade 1 adhesion and 320h water resistance on the GRPU substrate surface. In contrast, the coating film in Comparative Example 1 exhibited Grade 2 adhesion and 240h water resistance on the GRPU substrate surface. This demonstrates that the adhesion and water resistance of the coating film in this application are superior to commercially available products.

[0076] The difference between Comparative Examples 2-6 and Example 1 lies in the different amounts of resin, resin hydroxyl values, or curing agents used, resulting in a decrease in the performance of the prepared paint film.

[0077] The difference between Examples 4-6 and Example 1 is that the dispersant used is a mixture of nonionic polymeric dispersant and 2-hydroxy-4-methoxyacetophenone. Compared with a single dispersant, the water resistance of the paint film is significantly improved.

[0078] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A water-based fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates, characterized in that, Includes component A and component B; Component A comprises the following components in parts by weight: 55-60 parts of trifluoroether-based waterborne fluorocarbon resin with a hydroxyl value of 60-70 mg KOH / g; Solvent 4-6 parts; Water 7.3 parts; Dispersant 1.5-2 parts; 22-27 parts of filler; Component B comprises the following components in parts by weight: 40-60 parts of organosilicon-modified isocyanate trimer curing agent; 6-9 parts of silane coupling agent; Diluent 31-54 parts.

2. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 1, characterized in that: The trifluoroether-based waterborne fluorocarbon resin has a fluorine content of ≥13%.

3. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 1, characterized in that: The organosilicon-modified isocyanate trimer curing agent is Wanhua Aquolin 280 curing agent.

4. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 1, characterized in that: The silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

5. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 1, characterized in that: The dispersant is a mixture of a nonionic polymeric dispersant and 2-hydroxy-4-methoxyacetophenone.

6. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 5, characterized in that: The weight ratio of the nonionic polymeric dispersant to 2-hydroxy-4-methoxyacetophenone is 1:(0.3-0.5).

7. The waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to claim 1, characterized in that: The weight ratio of component A to component B is (5.8-6.2):

1.

8. A method for preparing a waterborne fluorocarbon paint with strong adhesion and high weather resistance for GRPU substrates according to any one of claims 1-7, characterized in that: Includes the following steps: S1. Mix the dispersant and water, add the filler and stir to obtain a dispersion slurry; mix the trifluoroether-based waterborne fluorocarbon resin, solvent and dispersion slurry, stir and adjust the pH to 7.5-8.5 to obtain component A; S2. Mix the diluent and silane coupling agent, add the isocyanate curing agent, and stir to obtain component B. S3. Mix components A and B to obtain the final product.