Thick coating type one-component water-based paint and method for preparing the same

Abstract

The application discloses a thick-coating type single-component water-based paint, which comprises the following components in percentage by weight: water-based alkyd resin 14-19%, air-drying agent 0.5-0.6%, amine neutralizer 0.1-0.2%, environment-friendly solvent 2-3%, deionized water 15-21%, first defoaming agent 0.1-0.15%, first batch of polyurethane resin 5-6%, anti-rust filler 30-40%, pigment 2-8%, second batch of polyurethane resin 1-4%, water-based acrylic resin 10-12%, toughening agent 2-3%, base material wetting agent 0.1-0.2%, second defoaming agent 0.1-0.15% and thickening agent 0.5-1%. The thick-coating type single-component water-based paint has high solid content, excellent anti-cracking performance of paint film, and excellent protective properties such as salt spray resistance and water resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical coatings, in particular to a thick-coating type single-component water-based paint and a preparation method thereof. BACKGROUND

[0002] Solvent-based acrylic polyurethane finish is widely used due to its simple construction, single-component self-drying, excellent comprehensive performance, and high cost performance. With the improvement of the national economy, the state's requirements for environmental protection are becoming increasingly stringent, and people's awareness of environmental protection is also increasing. Water-based paint is the inevitable trend of development, and researchers have been committed to converting oil-based polyurethane paint into water-based paint to reduce VOC emissions and protect the health of operators and users.

[0003] However, the water-based acrylic polyurethane finish on the market has the problem of easy cracking when thickly coated, which leads to coating defects and affects its performance. SUMMARY

[0004] To solve the above problems, the present application provides a thick-coating type single-component water-based paint and a preparation method thereof. The inventors have unexpectedly found that, during the preparation process, the use of a toughening agent and a polyurethane resin improves the anti-cracking film thickness of the product, and the product is obtained by refining and processing various selected raw materials, so that the paint film has better physical properties, salt spray resistance, water resistance, and other protective properties.

[0005] On the one hand, the thick-coating type single-component water-based paint provided by the present application comprises the following components in terms of weight percentage:

[0006]

[0007]

[0008] In some embodiments, the water-based alkyd resin is selected from 3AK0211Y from Tongde Chemical.

[0009] In some embodiments, the catalyst is a composite catalyst Troymax KC 10.

[0010] In some embodiments, the environmentally friendly solvent is DPNB; the first defoaming agent is Tego902W from DiGao; the second defoaming agent is BYK-028 from BIK Chemical; the anti-rust filler is a mixture of any two of zinc phosphate, molybdenum, calcium hydrate, siliconized dolomite, and aluminum zinc phosphate compound at a ratio of 3:1; the pigment is carbon black, titanium white, cadmium yellow, iron red, or iron blue; and the substrate wetting agent is anionic polyether siloxane polymer Lirui WET511.

[0011] In some embodiments, the first batch of polyurethane resin and the second batch of polyurethane resin are both waterborne polyurethane with core-shell structure modified by silicone, which is 3020 from Suzhou Pengcheng; the toughening agent is a multi-functional flexible polymer solution AC-9460.

[0012] In some embodiments, the waterborne acrylic resin is self-crosslinking, hyperbranched waterborne acrylic AP104A from KODAMA; the thickening agent is a hydrophobic alkali-swellable thickening agent, which is Rheovis AS1130, or a waterborne associated modified polyurethane thickening agent, which is a mixture of RM-8W from ROMENS and Rheolate 299 from HEMMIS in a weight ratio of 1:1.

[0013] In the present application, the root cause of cracking of existing coatings during drying is that, after the surface of the paint film is dried, shrinkage stress is generated during further crosslinking and drying of the paint film, which in turn causes the surface of the dried paint film to crack, resulting in cracks. The acrylic system is widely used due to its excellent characteristics, including its fast drying property, which itself limits its application field, such as not being able to be thickly coated, not being able to be rapidly baked, etc. In the present application, the good lipophilicity of the alkyd resin can ensure the application field of the coating, i.e. good wetting and spreading on substrates with high surface tension such as oil stains, without cracking. In addition, the system has excellent salt spray resistance, gloss, fullness, etc. In the actual application and test process of the customer, it is found that the addition of polyurethane resin and toughening agent can greatly improve the film thickness resistance of the system, and high-temperature baking can be performed immediately after spraying without cracking. The selected polyurethane resin has a core-shell structure with adjustable hardness, good flexibility, high adhesion strength, excellent low-temperature resistance, etc. The selected toughening agent is a multi-functional polymer that can combine the alkyd, acrylic, and polyurethane resins in the system to greatly enhance the flexibility and cracking resistance of the system.

[0014] In another aspect, the present application provides a preparation method of the thick-coating type one-component waterborne paint, in which the polyurethane resin is added to the reaction system in batches; the method comprises the following steps:

[0015] S1. Add the waterborne alkyd resin to the preparation kettle, heat and warm up, then add the catalyst and stir; then add the amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin, and first defoaming agent, and continuously heat and stir; then add the anti-rust filler and pigment, disperse uniformly, and then grind;

[0016] S2. To the ground slurry, add the second batch of polyurethane resin, water-based acrylic resin, toughening agent, substrate wetting agent and second defoaming agent in turn, stir, then add thickening agent, stir again, and obtain the thick coating type single-component water-based paint.

[0017] In some embodiments, the method for preparing a thick coating type single-component water-based paint comprises the following steps:

[0018] S1. Prepare materials according to the formula, add water-based alkyd resin into the material preparation pot, heat to 60-70℃, add catalyst and stir at 600-800r / min for 5 minutes; then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoaming agent, and continuously stir at 60-70℃ and 600-800r / min for 10 minutes; then add anti-rust filler and pigment, disperse uniformly, and grind to a fineness of not more than 10μm using a roll mill at 40-45℃;

[0019] S2. To the ground slurry, add water-based acrylic resin, toughening agent, substrate wetting agent and second defoaming agent in turn, stir at 900-1000r / min for 10 minutes, then add thickening agent, stir again at 900-1000r / min for 20 minutes, adjust the viscosity to 80-100s in T4 cup, and obtain the thick coating type single-component water-based paint.

[0020] Beneficial effects: The present application improves the specific steps of the preparation process, pre-mixes water-based alkyd resin with catalyst, and adds polyurethane resin, acrylic resin and toughening agent into the reaction system in batches. The use of specific polyurethane resin and toughening agent can make the product have high solid content, excellent anti-cracking performance, and excellent salt spray resistance and water resistance and other protective properties. DETAILED DESCRIPTION

[0021] The present application is described in detail below, and the examples are only used to explain the present application, and are not used to limit the scope of the present application. If no specific conditions are indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If no manufacturer of the reagent or instrument is indicated, it is a conventional product that can be purchased on the market.

[0022] Example 1

[0023] A dosage formula and preparation method of a thick coating type single-component water-based paint:

[0024]

[0025]

[0026] S1. Prepare materials according to the formula in the table above. Add water-based alkyd resin to the preparation pot, heat to 60°C, and stir at 600 r / min for 5 minutes. Then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoamer, and continue stirring at 60°C and 600 r / min for 10 minutes. Then add rust-inhibiting filler and pigment, disperse evenly, and grind at 40°C using a roller mill until the fineness is not higher than 10 μm.

[0027] S2. Add water-based acrylic resin, toughening agent, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, and stir at 900 r / min for 10 minutes. Then add thickener, stir again at 900 r / min for 20 minutes, and adjust the viscosity to 80-100s T4 cup viscosity to obtain the thick coating type single component water-based paint 1.

[0028] Among them: the water-based alkyd resin was selected from Tongde Chemical's 3AK0211Y; the drying agent was the composite drying agent TroymaxKC. 10; the environmentally friendly solvent is DPNB; the first defoamer is Tego902W from Digo; the second defoamer is BYK-028 from BYK Chemical; the rust-inhibiting filler is a mixture of any two of the following in a 3:1 ratio: zinc orthophosphate, molybdenum, calcium hydrate, silicified dolomite limestone, and aluminum zinc tripolyphosphate; the pigment is carbon black, titanium dioxide, cadmium yellow, iron oxide red, or iron blue; the substrate wetting agent is WET511, an anionic polyether siloxane polymer; both the first and second batches of polyurethane resin are silicone-modified waterborne polyurethane with a core-shell structure, specifically Suzhou Pengcheng's 3020; the toughening agent is AC-9460, a multifunctional flexible polymer solution; the waterborne acrylic resin is Keding's self-crosslinking, hyperbranched waterborne acrylic AP104A; the thickener is a hydrophobic alkali-swelling thickener or a waterborne associative modified polyurethane thickener, specifically Rheovis's hydrophobic alkali-swelling thickener. AS1130 is a waterborne associative modified polyurethane thickener, which is a mixture of Rohm and Haas's RM-8W and Hemings' Rheolate 299 in a 1:1 weight ratio.

[0029] Example 2

[0030] A dosage formulation and preparation method for a thick-coat type single-component water-based paint:

[0031]

[0032]

[0033] S1. Prepare materials according to the formula in the table above. Add water-based alkyd resin to the preparation pot, heat to 65°C, and stir at 700 r / min for 5 minutes. Then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoamer, and continue stirring at 65°C and 700 r / min for 10 minutes. Then add rust-inhibiting filler and pigment, disperse evenly, and grind at 42°C using a roller mill until the fineness is not higher than 10 μm.

[0034] S2. Add water-based acrylic resin, toughening agent, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, and stir at 950 r / min for 10 minutes. Then add thickener, stir again at 950 r / min for 20 minutes, and adjust the viscosity to 80-100s T4 cup viscosity to obtain the thick coating type single component water-based paint 2.

[0035] Among them: the water-based alkyd resin was selected from Tongde Chemical's 3AK0211Y; the drying agent was the composite drying agent TroymaxKC. 10; the environmentally friendly solvent is DPNB; the first defoamer is Tego902W from Digo; the second defoamer is BYK-028 from BYK Chemical; the rust-inhibiting filler is a mixture of any two of the following in a 3:1 ratio: zinc orthophosphate, molybdenum, calcium hydrate, silicified dolomite limestone, and aluminum zinc tripolyphosphate; the pigment is carbon black, titanium dioxide, cadmium yellow, iron oxide red, or iron blue; the substrate wetting agent is WET511, an anionic polyether siloxane polymer; both the first and second batches of polyurethane resin are silicone-modified waterborne polyurethane with a core-shell structure, specifically Suzhou Pengcheng's 3020; the toughening agent is AC-9460, a multifunctional flexible polymer solution; the waterborne acrylic resin is Keding's self-crosslinking, hyperbranched waterborne acrylic AP104A; the thickener is a hydrophobic alkali-swelling thickener or a waterborne associative modified polyurethane thickener, specifically Rheovis's hydrophobic alkali-swelling thickener. AS1130 is a waterborne associative modified polyurethane thickener, which is a mixture of Rohm and Haas's RM-8W and Hemings' Rheolate 299 in a 1:1 weight ratio.

[0036] Example 3

[0037] A dosage formulation and preparation method for a thick-coat type single-component water-based paint:

[0038] Raw materials Amount (wt%) Waterborne alkyd resin 16.5 Drier 0.5 Amine neutralizer 0.1 Environment-friendly solvent 2 Deionized water 18 First batch of polyurethane resin 6 First defoamer 0.1 Rust-proof filler 35 Pigment 8 Second batch of waterborne polyurethane resin 1 Toughening agent 2 Waterborne acrylic resin 10 Substrate wetting agent 0.1 Second defoamer 0.1 Thickening agent 0.6

[0039] S1. Prepare materials according to the formula in the table above. Add water-based alkyd resin to the preparation pot, heat to 70°C, and stir at 800 r / min for 5 minutes. Then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoamer, and continue stirring at 70°C and 800 r / min for 10 minutes. Then add rust-inhibiting filler and pigment, disperse evenly, and grind at 45°C using a roller mill until the fineness is not higher than 10 μm.

[0040] S2. Add water-based acrylic resin, toughening agent, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, and stir at 1000 r / min for 10 minutes. Then add thickener, stir again at 1000 r / min for 20 minutes, and adjust the viscosity to 80-100s T4 cup viscosity to obtain the thick coating type single component water-based paint 3.

[0041] Among them: the water-based alkyd resin was selected from Tongde Chemical's 3AK0211Y; the drying agent was the composite drying agent TroymaxKC. 10; the environmentally friendly solvent is DPNB; the first defoamer is Tego902W from Digo; the second defoamer is BYK-028 from BYK Chemical; the rust-inhibiting filler is a mixture of any two of the following in a 3:1 ratio: zinc orthophosphate, molybdenum, calcium hydrate, silicified dolomite limestone, and aluminum zinc tripolyphosphate; the pigment is carbon black, titanium dioxide, cadmium yellow, iron oxide red, or iron blue; the substrate wetting agent is WET511, an anionic polyether siloxane polymer; both the first and second batches of polyurethane resin are silicone-modified waterborne polyurethane with a core-shell structure, specifically Suzhou Pengcheng's 3020; the toughening agent is AC-9460, a multifunctional flexible polymer solution; the waterborne acrylic resin is Keding's self-crosslinking, hyperbranched waterborne acrylic AP104A; the thickener is a hydrophobic alkali-swelling thickener or a waterborne associative modified polyurethane thickener, specifically Rheovis's hydrophobic alkali-swelling thickener. AS1130 is a waterborne associative modified polyurethane thickener, which is a mixture of Rohm and Haas's RM-8W and Hemings' Rheolate 299 in a 1:1 weight ratio.

[0042] Comparative Example 1

[0043] A thick-coat type single-component water-based paint, the dosage formula and preparation method are the same as in Example 1, except that "polyurethane resin" and "toughening agent" are removed, specifically:

[0044]

[0045]

[0046] S1. Prepare materials according to the formula in the table above. Add water-based alkyd resin to the preparation pot, heat to 60°C, and stir at 600 r / min for 5 minutes. Then add amine neutralizer, environmentally friendly solvent, deionized water and first defoamer, and continue stirring at 60°C and 600 r / min for 10 minutes. Then add rust-inhibiting filler and pigment, disperse evenly, and grind at 40°C using a roller mill until the fineness is not higher than 10 μm.

[0047] S2. Add water-based acrylic resin, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, and stir at 900 r / min for 10 minutes. Then add thickener, stir again at 900 r / min for 20 minutes, and adjust the viscosity to 80-100s T4 cup viscosity to obtain thick coating type single component water-based paint.

[0048] The following components are used: the waterborne alkyd resin is selected from Tongde Chemical's 3AK0211Y; the drying agent is the composite drying agent TroymaxKC 10; the environmentally friendly solvent is DPNB; the first defoamer is Digo's Tego902W; the second defoamer is BYK-028 from BYK Chemical; the rust-inhibiting filler is a mixture of any two of the following compounds in a 3:1 ratio: zinc orthophosphate, molybdenum, calcium hydrate, silicified dolomite limestone, and aluminum zinc tripolyphosphate; the pigment is carbon black, titanium dioxide, cadmium yellow, iron oxide red, or iron blue; the substrate wetting agent is the anionic polyether siloxane polymer Lingrui WET511; the waterborne acrylic resin is Keding's self-crosslinking, hyperbranched waterborne acrylic AP104A; the thickener is a hydrophobic alkali-swelling thickener or a waterborne associative modified polyurethane thickener, with the hydrophobic alkali-swelling thickener being Rheovis. AS1130 is a waterborne associative modified polyurethane thickener, which is a mixture of Rohm and Haas's RM-8W and Hemings' Rheolate 299 in a 1:1 weight ratio.

[0049] Comparative Example 2

[0050] A thick-coat type single-component waterborne paint, the dosage formulation and preparation method are the same as in Example 1, except that the "type of polyurethane resin" is changed from "organosilicon-modified waterborne polyurethane with core-shell structure Suzhou Pengcheng 3020" to "polyester polyurethane", and the "type of toughening agent" is changed from "multifunctional flexible polymer solution AC-9460" to "styrene-propylene copolymer", with other conditions remaining unchanged.

[0051] Performance testing

[0052] The products of Examples 1-3 and Comparative Examples 1-2 were tested. Test samples were made simultaneously for thick coating operations, and the paint film was tested. The specific test results are shown in Table 1.

[0053] Table 1

[0054]

[0055]

[0056] As shown in Table 1, the thick-film single-component waterborne paints provided in Examples 1-3 of this application have a significant advantage in crack resistance compared to the products in Comparative Examples 1-2, resulting in superior performance. In other words, without using the "polyurethane resin and toughening agent" of this application, the final product exhibits reduced crack resistance, and using other types of "polyurethane resin and toughening agent" yields a paint film with better crack resistance than without.

[0057] In summary, this invention improves the specific steps of the preparation process by pre-mixing waterborne alkyd resin and drying agent, and adding polyurethane resin, acrylic resin and toughening agent to the reaction system in batches. By selecting specific polyurethane resin and toughening agent, the product can have a high solid content, better crack resistance of the paint film, and excellent protective properties such as salt spray resistance and water resistance.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these should also be considered within the scope of protection of the invention.

Claims

1. A thick-coat type single-component water-based paint, characterized in that, By weight percentage, it includes the following components: Waterborne alkyd resin 14%-19%, Drying agent 0.5%-0.6%, Amine neutralizer 0.1%-0.2%, Environmentally friendly solvents 2%-3%, Deionized water 15%-21%, First defoamer 0.1%-0.15%, The first batch of polyurethane resin contains 5%-6%. Rust-preventive filler 30%-40%, Pigment 2%-8%, The second batch of polyurethane resin is 1%-4%. Water-based acrylic resin 10%-12%, Toughening agent 2%-3%, Substrate wetting agent 0.1%-0.2%, The second defoamer is 0.1%-0.15%. Thickener 0.5%-1%; The first and second batches of polyurethane resin were both Suzhou Pengcheng's 3020; the toughening agent was AC-9460. It is prepared by the following steps: S1. Add water-based alkyd resin to the preparation pot, heat it up, add the drying agent and stir; then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoamer, and continue to keep it warm and stir; then add rust-inhibiting filler and pigment, disperse evenly and grind. S2. Add the second batch of polyurethane resin, water-based acrylic resin, toughening agent, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, stir, add thickener, stir again to obtain the thick coating type single component water-based paint.

2. The thick-coat type single-component water-based paint according to claim 1, characterized in that, The waterborne alkyd resin is selected from Tongde Chemical's 3AK0211Y.

3. The thick-coat type single-component water-based paint according to claim 1, characterized in that, The drying agent is a composite drying agent Troymax KC 10.

4. The thick-coating type single-component water-based paint according to claim 1, characterized in that, The environmentally friendly solvent is DPNB; the first defoamer is Tego902W from Digo; the second defoamer is BYK-028 from BYK Chemical; the pigment is carbon black, titanium dioxide, cadmium yellow, iron oxide red, or iron oxide blue; and the substrate wetting agent is WET511, an anionic polyether siloxane polymer.

5. The thick-coat type single-component water-based paint according to claim 1, characterized in that, The waterborne acrylic resin is Keding self-crosslinking, hyperbranched waterborne acrylic AP104A; the thickener is a hydrophobic alkali-swellable thickener or a waterborne associative modified polyurethane thickener. The hydrophobic alkali-swellable thickener is Rheovis AS1130, and the waterborne associative modified polyurethane thickener is a mixture of Rohm and Haas RM-8W and Hemings Rheolate 299 in a weight ratio of 1:

1.

6. The thick-coat type single-component water-based paint according to claim 1, characterized in that, It is prepared by the following steps: S1. Prepare materials according to the formula. Add water-based alkyd resin to the preparation pot, heat to 60-70℃, add and stir at 600-800r / min for 5 minutes; then add amine neutralizer, environmentally friendly solvent, deionized water, first batch of polyurethane resin and first defoamer, and continue stirring at 60-70℃ and 600-800r / min for 10 minutes; then add rust-inhibiting filler and pigment, disperse evenly, and grind at 40-45℃ using a roller mill until the fineness is not higher than 10μm; S2. Add water-based acrylic resin, toughening agent, substrate wetting agent and second defoamer to the slurry obtained by grinding in sequence, and stir at a speed of 900-1000 r / min for 10 minutes. Then add thickener, stir again at a speed of 900-1000 r / min for 20 minutes, and adjust the viscosity to T4 cup viscosity of 80-100s to obtain the thick coating type single component water-based paint.

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