Water-based two-component matte solid-color finish paint with high scratch resistance and preparation method of water-based two-component matte solid-color finish paint

Abstract

The invention discloses high-scratch-resistance water-based double-component matte solid color finish paint which comprises a component I and a component II, and the component I is prepared from the following raw materials in percentage by weight: 50-60% of matrix resin, 0.1-1% of a defoaming agent, 1-5% of a coalescing agent, 0.1-0.5% of a wetting dispersant, 1-5% of a delustering agent, 0.1-1% of a thickening agent, 20-40% of color paste, 0.1-0.5% of a mildew preventive and the balance of water, the component II at least comprises a curing agent. The combination of the water-based matte polyurethane emulsion and the water-based hydroxyl acrylic acid dispersion is adopted as matrix resin, and a prepared paint film has low glossiness, is high in drying speed on the surface of woodware, good in adhesive force with the woodware and excellent in scratch resistance and has self-extinction performance.

Description

Technical Field

[0001] The invention relates to C09D and the field of coating compositions, and in particular to a highly scratch-resistant water-based two-component matte solid-color topcoat and a preparation method thereof. Background Art

[0002] With the change of people's aesthetic level and the improvement of environmental protection requirements, wood products are widely welcomed by consumers. However, solvent-based wood paint will volatilize harmful gases during the drying process on the wood surface, affecting the health of the construction workers and the living comfort of consumers. In order to improve environmental protection requirements, water-based wood paint has gradually become popular among consumers, but water-based wood paint has the defects of insufficient hardness, easy scratching, easy yellowing, and high construction requirements. Therefore, it is very important to develop a water-based solid color topcoat with high scratch resistance and matte finish.

[0003] Chinese invention patent CN104789109B discloses an environmentally friendly water-based wood finish and a preparation method thereof. The environmentally friendly water-based wood finish prepared by using acrylic modified polyurethane with neem bark powder and celangulin powder as anti-insect powder has good anti-insect and anti-moth effects, strong scratch resistance, wear resistance, and high hardness, which greatly improves the service life of the product. However, the paint film has a high hardness and poor adhesion to wood. Chinese invention patent CN114196307A discloses a high-hardness, high-fullness, low-curing agent water-based two-component wood clear topcoat and a preparation method thereof. The use of silicon-modified hydroxyl acrylic emulsion can improve the hardness of the paint film, the hardness rises quickly, reduces the surface free radical energy, improves water resistance, weather resistance, etc., and can provide better stability of the paint film. However, the introduction of silicon dioxide will affect the scratch resistance of the paint film. Summary of the invention

[0004] In order to develop a water-based solid color topcoat with high scratch resistance and matte finish, the first aspect of the present invention provides a water-based two-component matte solid color topcoat with high scratch resistance, comprising component I and component II, wherein the raw materials for preparing component I include, by weight percentage, 50-60% of a main resin, 0.1-1% of a defoaming agent, 1-5% of a film-forming aid, 0.1-0.5% of a wetting and dispersing agent, 1-5% of a matting agent, 0.1-1% of a thickener, 20-40% of a color paste, 0.1-0.5% of a mildewproofing agent, and water is supplemented to 100%, and component II at least includes a curing agent.

[0005] As a preferred embodiment, the main resin includes polyurethane emulsion and acrylic dispersion, and the weight ratio of the polyurethane emulsion to the acrylic dispersion is (40-50): (5-20).

[0006] As a preferred embodiment, the polyurethane emulsion is a water-based matte polyurethane emulsion; and the acrylic dispersion is a water-based hydroxylated acrylic dispersion.

[0007] As a preferred embodiment, the weight ratio of the aqueous matte polyurethane emulsion to the aqueous hydroxylated acrylic dispersion is (43-48):(8-13).

[0008] As a preferred embodiment, the weight ratio of the aqueous matte polyurethane emulsion to the aqueous hydroxylated acrylic dispersion is 45:10.

[0009] During the experiment, the inventor found that the paint film prepared by using a combination of a water-based matte polyurethane emulsion and a water-based hydroxylated acrylic dispersion as the main resin has a lower gloss, dries quickly on the wood surface, and has good adhesion to the wood. The possible reason is speculated to be: the combination of a water-based matte polyurethane emulsion and a water-based hydroxylated acrylic dispersion itself has a lower gloss, and the formed topcoat has a high-grade texture, and the combination with a hydroxy-containing acrylic dispersion can increase the fullness and wrapping of the paint film, and improve the closed protection of the paint surface to the wood.

[0010] As a preferred embodiment, the matting agent is selected from at least one of wax powder, silicon powder, silicon dioxide, polyethylene wax, diatomaceous earth and titanium dioxide.

[0011] As a preferred embodiment, the wax powder is spherical wax powder, and the particle size of the spherical wax powder is 1-10 μm.

[0012] The inventors further discovered that the introduction of spherical wax powder can improve the feel of the paint surface without reducing the scratch resistance of wood paint. The reason may be that when an object contacts the coating surface, the spherical wax powder tends to roll more, so the sliding tendency is greater than the scratching tendency, and the impact of the outside world can be resolved in the wood paint to prevent scratches. Matt powder matting agents have poor scratch resistance for soft wood paints due to their low hardness and are prone to scratches.

[0013] As a preferred embodiment, the defoamer is an organosilicon defoamer. Preferably, the organosilicon defoamer comprises a combination of TEGO 902W and TEGO 810.

[0014] As a preferred embodiment, the weight ratio of TEGO 902W to TEGO 810 is (0.3-0.8): (0.1-0.5).

[0015] As a preferred embodiment, the weight ratio of TEGO 902W to TEGO 810 is 0.5:0.3.

[0016] As a preferred embodiment, the film-forming aid includes at least one of dipropylene glycol butyl ether, dipropylene glycol methyl ether, ethylene glycol tert-butyl ether, propylene glycol phenyl ether, and propylene glycol dimethyl ether.

[0017] As a preferred embodiment, the film-forming aid is a combination of dipropylene glycol butyl ether and dipropylene glycol methyl ether.

[0018] As a preferred embodiment, the weight ratio of dipropylene glycol butyl ether to dipropylene glycol methyl ether is (1-3): (1-3).

[0019] As a preferred embodiment, the weight ratio of dipropylene glycol butyl ether to dipropylene glycol methyl ether is 2:2.

[0020] As a preferred embodiment, the thickener is a polyether siloxane thickener, and the polyether siloxane thickener includes a combination of 299 and PUR44.

[0021] As a preferred embodiment, the weight ratio of 299 to PUR44 is (0.1-0.3): (0.3-0.5).

[0022] As a preferred embodiment, the weight ratio of 299 to PUR44 is 0.2:0.4.

[0023] As a preferred embodiment, the color paste includes color powder, water and additives, the additives include dispersants and anti-settling agents, and the weight ratio of the dispersants to the anti-settling agents is (1-10): (0.1-0.5).

[0024] As a preferred embodiment, the weight ratio of the dispersant to the anti-settling agent is 7:0.2.

[0025] As a preferred embodiment, the weight ratio of the toner, water and auxiliary agent is (60-80):(20-30):(5-11).

[0026] As a preferred embodiment, the weight ratio of the toner, water and auxiliary agent is 70:22.8:7.2.

[0027] As a preferred embodiment, the method for preparing the color paste includes the following steps: adding part of the water into the reactor, starting stirring, adjusting the speed to 700-900r / min, adding dispersant and color powder in sequence, adjusting the speed to 1000-1300r / min and dispersing for 20-30min, detecting the fineness to <20μm, adjusting the speed to 700-900r / min, adding anti-settling agent and remaining water in sequence, continuing to disperse for 5-15min, and obtaining the color paste.

[0028] As a preferred embodiment, the component II includes a solvent and a curing agent, and the weight ratio of the solvent to the curing agent is (15-25): (70-90).

[0029] As a preferred embodiment, the weight ratio of the solvent to the curing agent is 20:80.

[0030] As a preferred embodiment, the curing agent comprises a hydrophilic aliphatic polyisocyanate and an oily aliphatic isocyanate trimer, and the weight ratio of the hydrophilic aliphatic polyisocyanate to the oily aliphatic isocyanate trimer is (30-50): (30-50).

[0031] As a preferred embodiment, the weight ratio of the hydrophilic aliphatic polyisocyanate to the oily aliphatic isocyanate trimer is 40:40.

[0032] As a preferred embodiment, the water-based curing agent is a hydrophilic aliphatic polyisocyanate, and the trimer curing agent is an aliphatic isocyanate trimer.

[0033] The curing agent is a combination of hydrophilic aliphatic polyisocyanate and aliphatic isocyanate trimer, with a weight ratio of 1:1. The prepared wood paint has a certain toughness, can have a good bonding effect with the wood substrate, and avoids the problem of reduced scratch resistance caused by excessive addition of matting agent, and the stability of the topcoat is relatively high. The reason may be: the aliphatic isocyanate trimer reacts with the acrylic resin, which improves the hardness of the system polymer to a certain extent, so that the wood paint takes into account both toughness and hardness, and balances the adhesion to wood and the scratch resistance of the wood paint. However, the aliphatic isocyanate trimer has poor compatibility in the water-based paint system and there is a risk of precipitation of particles. The combination of hydrophilic aliphatic polyisocyanate and aliphatic isocyanate trimer improves the compatibility of the aliphatic isocyanate trimer in the system, avoids coarsening of the topcoat, and improves the stability of the topcoat.

[0034] A second aspect of the present invention provides a method for preparing a highly scratch-resistant water-based two-component matte solid color topcoat, comprising the following steps:

[0035] S1 prepares color paste for standby use;

[0036] S2: Add the main resin to the reactor, turn on the stirrer, adjust the speed to 700-900r / min, then add the defoamer, the premixed film-forming aid and water, the wetting dispersant, the matting agent, adjust the speed to 1000-1300r / min, disperse for 20-30min, detect the fineness to <35μm and no shrinkage cavity, adjust the speed to 700-900r / min, add the thickener, color paste, water, mildewproof agent, continue to disperse for 5-15min, and obtain component I;

[0037] S3 prepares component II, and components I and II are packaged separately.

[0038] As a preferred embodiment, the preparation method of component II comprises the following steps: mixing the solvent and the curing agent, and dispersing them at 700-900 r / min for 10-20 min.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The highly scratch-resistant water-based two-component matte solid color topcoat of the present invention adopts a combination of a water-based matte polyurethane emulsion and a water-based hydroxy acrylic dispersion as the main resin. The resulting paint film has a lower glossiness, dries quickly on the surface of wood, and has good adhesion to the wood.

[0041] (2) The highly scratch-resistant water-based two-component matte solid color topcoat of the present invention can improve the feel of the paint surface by introducing spherical wax powder, while not reducing the scratch resistance of the wood paint.

[0042] (3) The highly scratch-resistant water-based two-component matte solid color topcoat of the present invention has a curing agent which is a combination of a hydrophilic aliphatic polyisocyanate and an aliphatic isocyanate trimer. The prepared wood paint has a certain toughness and can have a good bonding effect with the wood substrate. It also avoids the problem of decreased scratch resistance caused by excessive addition of the matting agent, and the topcoat has a high stability.

[0043] (4) The highly scratch-resistant water-based two-component matte solid color topcoat of the present invention has a relatively good hand feel, has a relatively good wrapping property for the color paste, is not easily scratched, has relatively good adhesion performance, and has a self-matting property.

[0044] (5) The highly scratch-resistant water-based two-component matte solid color topcoat of the present invention has a good matte texture and enhances the high-grade color of wood products. DETAILED DESCRIPTION

[0045] Example

[0046] A highly scratch-resistant water-based two-component matte solid color topcoat comprises component I and component II, and the raw materials for preparation are shown in Table 1:

[0047] Table 1

[0048]

[0049]

[0050] The sources of the raw materials are shown in Table 2.

[0051] Table 2

[0052]

[0053]

[0054] The preparation method of the color paste comprises the following steps: adding part of the water into the reactor, starting stirring, adjusting the rotation speed to 800 r / min, adding the dispersant and the color powder in sequence, adjusting the rotation speed to 1200 r / min and dispersing for 25 min, detecting the fineness to be less than 20 μm, adjusting the rotation speed to 800 r / min, adding the anti-settling agent and the remaining water in sequence, continuing to disperse for 10 min, and obtaining the color paste.

[0055] A method for preparing a highly scratch-resistant water-based two-component matte solid color topcoat comprises the following steps:

[0056] S1 prepares color paste for standby use;

[0057] S2: Add the main resin to the reactor, start the stirrer, adjust the speed to 800r / min, then add the defoamer, the premixed film-forming aid and water (premixed at a weight ratio of 4:2), the wetting dispersant, the matting agent, adjust the speed to 1200r / min and disperse for 25min, detect the fineness to <35μm and no shrinkage cavity, adjust the speed to 800r / min, add the thickener, color paste, water, mildew inhibitor, continue to disperse for 10min, and obtain component I;

[0058] S3 prepares component II, and components I and II are packaged separately.

[0059] The preparation method of component II comprises the following steps: mixing the solvent and the curing agent, and dispersing them at 800 r / min for 15 minutes.

[0060] Performance Testing

[0061] Mix component I, component II and water in a ratio of 100:10:10. 2 Spray the coating amount evenly on the prepared wooden board;

[0062] Dry at room temperature for 30 minutes, transfer to a 50°C oven to dry for 4 hours, and leave overnight at room temperature for testing; 1. Glossiness: Refer to GB / T 9754-2007 standard and use a gloss meter to read the 60° angle data;

[0063] 2. Resistance to moisture and heat: Tested in accordance with GB / T4893.2-2020. The principle is to place a heat source block heated to 70°C on a wet cloth in direct contact with the test surface. After 15 minutes, remove the heat source block and the wet cloth, and place the test sample for 16 to 24 hours without interference. Wipe the test surface clean and check for damage, such as fading, discoloration, bulging, expansion, etc. The test results are evaluated with digital grades. Level 1 means no change, and the test area is indistinguishable from the adjacent areas; Level 2 means slight change, and the test area and adjacent areas can only be distinguished when the light source illuminates the paint film surface, and there is no change in the test surface structure, such as expansion, fiber protrusions, cracking, and blistering; Level 3 means moderate change, and the test area and adjacent areas can be distinguished in several directions, and there is no change in the test surface structure, such as expansion, fiber protrusions, cracking, and blistering; Level 4 means obvious change, and the test area and adjacent areas can be distinguished in all directions, and there is slight change in the test surface structure, such as expansion, fiber protrusions, cracking, and blistering; Level 5 means severe change, and the test surface structure is obviously changed, such as fading, discoloration, bulging, expansion, etc.

[0064] 3. Adhesion: Refer to GB / T 9286-1998 standard, use a grid knife to scratch, and pull the adhesive tape to see if the paint film falls off, and classify it according to the degree of shedding;

[0065] 4. Scratch resistance: Place your finger naturally on the board, with your fingernail touching the paint film, and rub the paint surface clockwise 20 times within a 5cm*5cm area. Under light, if no scratches can be seen from any angle, it is rated as Level 1; if slight scratches can only be seen at one angle, it is rated as Level 2; if slight scratches can be seen at 2-3 angles, it is rated as Level 3; if slight scratches can be seen at multiple angles, it is rated as Level 4; if obvious scratches can be seen at multiple angles, it is rated as Level 5.

[0066] The test results are shown in Table 3.

[0067] Table 3

[0068]

[0069]

[0070] Note: The moisture and heat resistance levels are 1-5, with 1 being the best. The scratch resistance levels are 1-5, with 1 being the best. The adhesion levels are 0-5, with 0 being the best.

[0071] According to the test results in Table 3, it can be obtained that: compared with the results of Examples 1-4, Example 1 has the best moisture and heat resistance and scratch resistance; Example 3 has a lower gloss, but the matte emulsion has poor encapsulation of the white slurry, resulting in decreased scratch resistance and adhesion performance; Example 4 has a higher gloss, the resin does not have self-matting properties, and has poor scratch resistance.

[0072] Comparing the results of Examples 1, 5-7, the matting properties of Examples 5 and 6 are better than those of Example 1, but not as good as those of Example 1 in terms of scratch resistance; Example 7 is comparable to Example 1 in terms of matting property and moisture and heat resistance, but slightly worse in terms of scratch resistance.

[0073] Comparing the results of Examples 1, 8-9, the gloss of Examples 8 and 9 is higher than that of Example 1, and the scratch resistance is not as good as that of Example 1. The mixing of N3800 curing agent into Example 1 has obvious improvements in both matting and scratch resistance.

Claims

1. A highly scratch-resistant water-based two-component matte solid color topcoat, characterized in that: The invention comprises component I and component II. The raw materials for preparing component I include, by weight percentage, 50-60% of main resin, 0.1-1% of defoaming agent, 1-5% of film-forming aid, 0.1-0.5% of wetting dispersant, 1-5% of matting agent, 0.1-1% of thickener, 20-40% of color paste, 0.1-0.5% of mildewproof agent, and water is added to 100%. Component II at least comprises a curing agent.

2. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The main resin includes polyurethane emulsion and acrylic dispersion, and the weight ratio of the polyurethane emulsion to the acrylic dispersion is (40-50): (5-20).

3. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The matting agent is selected from at least one of wax powder, silicon powder, silicon dioxide, polyethylene wax, diatomaceous earth and titanium dioxide.

4. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The wax powder is spherical wax powder, and the particle size of the spherical wax powder is 1-10 μm.

5. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The film-forming aid includes at least one of dipropylene glycol butyl ether, dipropylene glycol methyl ether, ethylene glycol tert-butyl ether, propylene glycol phenyl ether, and propylene glycol dimethyl ether.

6. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The color paste includes color powder, water and auxiliary agents, wherein the auxiliary agents include dispersants and anti-settling agents, and the weight ratio of the dispersants to the anti-settling agents is (1-10): (0.1-0.5).

7. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 6, characterized in that: The weight ratio of the toner, water and auxiliary agent is (60-80):(20-30):(5-11).

8. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 1, characterized in that: The component II includes a solvent and a curing agent, and the weight ratio of the solvent to the curing agent is (15-25): (70-90).

9. The highly scratch-resistant water-based two-component matte solid color topcoat according to claim 8, characterized in that: The curing agent comprises hydrophilic aliphatic polyisocyanate and oily aliphatic isocyanate trimer, and the weight ratio of the hydrophilic aliphatic polyisocyanate to the oily aliphatic isocyanate trimer is (30-50): (30-50).

10. A method for preparing the highly scratch-resistant water-based two-component matte solid color topcoat according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1 prepares color paste for standby use; S2: Add the main resin to the reactor, turn on the stirrer, adjust the speed to 700-900r / min, then add the defoamer, the premixed film-forming aid and water, the wetting dispersant, the matting agent, adjust the speed to 1000-1300r / min, disperse for 20-30min, detect the fineness to <35μm and no shrinkage cavity, adjust the speed to 700-900r / min, add the thickener, color paste, water, mildewproof agent, continue to disperse for 5-15min, and obtain component I; S3 prepares component II, and components I and II are packaged separately.

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