EB-cured antibacterial skin-feeling wood lacquer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of wood coatings, in particular to EB-cured antibacterial skin-feeling wood paint as well as a preparation method and application thereof. The matte paint comprises the following components in parts by weight: 40-60 parts of polyurethane acrylate, 20-40 parts of a reactive diluent, 0.5-1 part of an acrylate leveling agent, 0.1-0.5 part of a light stabilizer, 0.1-0.5 part of a photoinitiator, 1-5 parts of a radiation curing leveling agent, 1-3 parts of an antibacterial agent, 5-10 parts of matte powder and 0.2-1 part of an organic silicon leveling agent. The product has excellent yellowing resistance after EB curing, the hardness of the coating is greater than 4H, the weather resistance and wear resistance are excellent, the antibacterial property is good, the odor is low, and the actual use effect is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of wood coatings, and in particular to an EB-cured antibacterial skin-feel wood coating and a preparation method and application thereof. Background Art

[0002] Wood paint has the advantages of protection, beauty, easy cleaning, many environmental protection options, wide application, rapid technological progress and simple construction. Although it has high production efficiency, short cycle and is green and environmentally friendly, it still has problems such as curing rate limitation, insufficient deep penetration, monomer residue and strong odor. To solve these problems, EB (electron beam) curing technology came into being. It uses high-energy electron beams to directly act, high-speed curing at room temperature, deep penetration, thorough curing and environmental protection and energy saving, which is 60% more energy-efficient than UV curing. Although UV-curing coatings are excellent in environmental protection, rapid curing and surface performance, there are no UV coatings on the market that meet the requirements of antibacterial, scratch resistance, matte and environmental protection at the same time, especially products combined with EB curing technology. Therefore, it is urgent to develop EB-cured topcoats that have coating performance, soft antibacterial skin feel, excellent hardness and weather resistance.

[0003] Chinese invention patent CN112143356B discloses a water-based skin-feel super-matte wood paint, which is prepared from two components A and B, wherein component A includes the following components by mass: self-matting water-based polyurethane dispersion, water-based self-crosslinking acrylic emulsion, film-forming aid, organic fluorine acid and water; the component B is polymerized aziridine. The water-based skin-feel super-matte wood paint obtained by mixing components A and B has the advantages of excellent adhesion performance, natural super-matte gloss and outstanding skin touch; and the surface of the paint film is endowed with anti-scratch self-repairing properties, and it can also prevent the paint film from leaving hand sweat during the touch process of human hands. However, the invention does not involve the study of anti-scratch and antibacterial properties. Summary of the invention

[0004] The first aspect of the present invention provides an EB-cured antibacterial skin-feel wood paint, which comprises, by weight, 40-60 parts of polyurethane acrylate, 20-40 parts of reactive diluent, 0.5-1 part of acrylate leveling agent, 0.1-0.5 part of light stabilizer, 0.1-0.5 part of photoinitiator, 1-5 parts of radiation-cured leveling agent, 1-3 parts of antibacterial agent, 5-10 parts of matte powder and 0.2-1 part of silicone leveling agent.

[0005] The polyurethane acrylate includes 6-functionality polyurethane acrylate and 3-functionality polyurethane acrylate.

[0006] This application study found that by selecting a compound of 6-functionality polyurethane acrylate and 3-functionality polyurethane acrylate and limiting the viscosity range of the two, the matte performance can be improved, thereby improving the skin feel. It may be that the compounding of the two balances the crosslinking density, curing rate and roughness of the coating surface. Further research found that by limiting the weight ratio of 6-functionality polyurethane acrylate and 3-functionality polyurethane acrylate to 1: (0.5-1.5), the gloss of the paint film can be reduced to below 5°, and the hand feel μs <0.3. The specific compounding ratio changes the roughness of the coating surface and promotes the distribution of matte powder particles, thereby affecting the intensity of scattered light.

[0007] The viscosity of the hexafunctional polyurethane acrylate at 25° C. is 40000-80000 mPa·s.

[0008] Preferably, the viscosity of the hexafunctional polyurethane acrylate at 25° C. is 55000-75000 mPa·s.

[0009] More preferably, the hexafunctional polyurethane acrylate is selected from at least one of the following brands of Changxing Chemical Industry Co., Ltd.: Etercure 6145-100, Etercure 6103, and Etercure 6169.

[0010] The trifunctional polyurethane acrylate has a viscosity of 1000-5000 mPa·s at 60° C.

[0011] Preferably, the trifunctional polyurethane acrylate has a viscosity of 1000-3000 mPa·s at 60°C.

[0012] The weight ratio of the 6-functionality polyurethane acrylate to the 3-functionality polyurethane acrylate is 1:(0.5-1.5).

[0013] Preferably, the weight ratio of the 6-functionality polyurethane acrylate to the 3-functionality polyurethane acrylate is 1:(0.5-1).

[0014] The active diluent includes one or more of TPGDA (tripropylene glycol diacrylate), HDDA (hexanediol diacrylate), DPGDA (dipropylene glycol diacrylate), PEGDA (polyethylene glycol diacrylate), 3EOTMPTA (3-ethoxytrimethylolpropane triacrylate), and DPHA (dipentaerythritol hexaacrylate).

[0015] The active diluent includes 3EOTMPTA and HDDA, and the mass ratio of 3EOTMPTA to HDDA is (1-3):1.

[0016] The applicant has found that the active diluents selected from 3EOTMPTA and HDDA, and the mass ratio of 3EOTMPTA and HDDA is limited to (1-3): 1, can simultaneously improve the hardness and toughness of the paint film, thereby improving the wear resistance of the paint film. Both 3EOTMPTA and HDDA contain acrylate functional groups, which can quickly initiate polymerization reactions under EB radiation, thereby promoting the curing of wood paint. The compound use of these two active diluents can further increase the curing rate of wood paint, shorten the curing time, and improve the bonding strength and production efficiency of the product. In addition, since HDDA has a longer carbon chain, it can provide better flexibility and adhesion, while 3EOTMPTA has a faster curing speed and higher hardness. The combination of the two can achieve a more efficient curing process; 3EOTMPTA can provide better hardness and wear resistance, while HDDA gives the cured film better flexibility and adhesion. After compounding, a good balance between hardness and flexibility can also be achieved.

[0017] Preferably, the mass ratio of 3EOTMPTA to HDDA is (1-2):1.

[0018] The antibacterial agents include guanidine and double-chain quaternary ammonium salts.

[0019] Conventional antimicrobial agents contain long alkyl chains, which reduce compatibility with polyurethane and are prone to antimicrobial agent precipitation, resulting in improved glossiness. This application study found that antimicrobial agents include guanidine groups and double-chain quaternary ammonium salts, which can improve antimicrobial properties while maintaining a matte effect. Guanidine groups have high activity, and polymers are positively charged. Bacteria and viruses can be unable to split and reproduce by adsorption, collapse of cell membrane structure, and formation of closed films, and lose activity. At the same time, double-chain quaternary ammonium salts can produce synergistic effects to further improve adsorption performance and antimicrobial properties due to the presence of two long-chain hydrophobic groups in the molecular structure. At the same time, guanidine groups and double-chain quaternary ammonium salts can promote the dispersion of polyurethane segments with different functionalities, avoiding affecting the paint film drying process and avoiding gloss uniformity.

[0020] Preferably, the antimicrobial agent brand includes Polyphase AF3 and / or KEPUYIN-J139.

[0021] The added amount of the photoinitiator is not higher than 0.3 wt %.

[0022] Preferably, the added amount of the photoinitiator is not higher than 0.2 wt %.

[0023] The weight ratio of the radiation curing leveling agent, the acrylic leveling agent and the silicone leveling agent is 1: (0.05-0.4): (0.2-0.6).

[0024] Preferably, the weight ratio of the radiation curing leveling agent, the acrylate leveling agent and the silicone leveling agent is 1:(0.05-0.2):(0.2-0.4).

[0025] The research in this application found that limiting the weight ratio of radiation curing leveling agent, acrylic leveling agent and silicone leveling agent to 1: (0.05-0.4): (0.2-0.6) can further improve the wear resistance of the paint film and achieve 0.03g of no paint film wear-through. The acrylic leveling agent can effectively reduce the surface tension of wood paint, so that it can form a smoother and more uniform coating during the coating process. The use of radiation curing leveling agent can further reduce the surface tension of wood paint, making it easier to spread on the substrate. During the EB curing process, the fluidity of wood paint is improved, thereby ensuring that the coating has excellent flatness and smoothness after curing. The silicone leveling agent can effectively promote the dispersibility between matt powder particles and the system.

[0026] Preferably, the light stabilizer comprises at least one of the following brands of BASF: Tinuvin 1130, Tinuvin 234, Tinuvin 328, Tinuvin 770, Tinuvin 900, Tinuvin 400, Tinuvin 477, Tinuvin 405, Tinuvin 144, Tinuvin 152.

[0027] The photoinitiator includes one or more of: TPO (diphenyl-(2,4,6-trimethylbenzoyl)phosphine), MBF (methyl phenylacetonate), photoinitiator 184 (1-hydroxycyclohexyl phenyl ketone), photoinitiator 907 (2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone), and ITX (2-isopropylthioxanthone).

[0028] Preferably, the photoinitiator includes: TPO and MBF, both of which can be purchased from Tianjin Jiuri New Materials Co., Ltd.; the mass ratio of TPO to MBF is 1:(0.5-1.5).

[0029] Preferably, the brands of the radiation curing leveling agent include TEGO Rad 2200N and / or TEGO Rad 2700 produced by Evonik Specialty Chemicals GmbH.

[0030] The matte powder includes at least one of the following brands: ED-2, A360Z, RAD2105, C-7, and ED-80.

[0031] Preferably, the matte powder is of brand RAD2105, purchased from Grace Specialty Chemicals.

[0032] The organosilicon leveling agent includes at least one of the following brands of Evonik Specialty Chemicals Co., Ltd.: BYK-331, BYK-378, BYK-3700, TEGO 450, TEGO 2100, and SF-6045.

[0033] Preferably, the brand of the organosilicon leveling agent is TEGO 450.

[0034] The acrylic leveling agent includes at least one of the following brands: EFKA-3777, Levaslip-432, BYK-358N, QH-043, and BYK-354.

[0035] Preferably, the brand of the acrylic leveling agent is BYK-358N, purchased from BYK Chemical.

[0036] The second aspect of the present invention provides a method for preparing an EB-cured antibacterial skin-feel wood paint, comprising the following steps:

[0037] S1. Add polyurethane acrylate and reactive diluent in sequence, and stir to disperse evenly;

[0038] S2, add acrylic leveling agent and light stabilizer, stir and disperse evenly;

[0039] S3, add matte powder and photoinitiator, stir and disperse evenly, and control the fineness of particles in the system to ≤20μm;

[0040] S4. Add radiation curing leveling agent, antibacterial agent and silicone leveling agent, and stir to disperse evenly.

[0041] The stirring speed is 700-1200 rpm.

[0042] Preferably, the method for preparing the EB-cured antibacterial skin-feel wood paint comprises the following steps:

[0043] S1. Add polyurethane acrylate and reactive diluent in sequence, and stir and disperse at 800-1000 rpm for 10-30 to make them completely dispersed;

[0044] S2, then add acrylic leveling agent and light stabilizer, continue to stir and disperse at 800-1000rpm for 10-30 minutes to make it completely dispersed;

[0045] S3, add matte powder and photoinitiator, continue to stir and disperse at 800-1000rpm for 10-30, and control the fineness of particles in the system to be ≤20μm;

[0046] S4. Add radiation curing leveling agent, antibacterial agent and silicone leveling agent, continue stirring and dispersing at 800-1000 rpm for 10-30 minutes to make it completely dispersed, and then cool to room temperature to obtain.

[0047] The third aspect of the present invention provides an application of an EB-cured antibacterial skin-feel wood paint, which is applied to a wood substrate by rubber roller coating, laser roller coating or forward and reverse roller coating.

[0048] Beneficial Effects

[0049] 1. By selecting a compound of 6-functionality polyurethane acrylate and 3-functionality polyurethane acrylate and limiting the viscosity range of the two, the matte performance can be improved, thereby improving the skin feel.

[0050] 2. By limiting the weight ratio of 6-functional polyurethane acrylate to 3-functional polyurethane acrylate to 1:

[0051] (0.5-1.5), the glossiness of the paint film can be reduced to below 5°, and the hand feel μs<0.3.

[0052] 3. The active diluents are 3EOTMPTA and HDDA, and the mass ratio of 3EOTMPTA and HDDA is limited to (1-3):1, which can simultaneously improve the hardness and toughness of the paint film, thereby improving the wear resistance of the paint film.

[0053] 4. The mass ratio of 3EOTMPTA and HDDA is limited to (1-2):1, which can reduce the amount of photoinitiator added to no more than 0.3wt% while maintaining the curing performance.

[0054] 5. The weight ratio of radiation curing leveling agent, acrylic leveling agent and silicone leveling agent is limited to 1:

[0055] (0.05-0.4): (0.2-0.6), which can further improve the wear resistance of the paint film and reach 0.03g without paint film wear.

[0056] 6. Antibacterial agents include guanidine and double-chain quaternary ammonium salts, which can improve the antibacterial performance while maintaining the matte effect.

[0057] 7. The EB-cured antibacterial skin-feel wood paint prepared in the present application can be applied to the coating of the wood substrate by any one of rubber roller coating, laser roller coating, and forward and reverse roller coating.

[0058] 8. The wood paint provided by the present invention has a simple construction process and is easy to operate. The paint surface hardness is ≥5H, the yellowing resistance exceeds the national standard level 1, the weather resistance is excellent, and the scratch resistance is excellent. The product has excellent antibacterial and stain resistance.

[0059] 9. The preparation raw materials do not include organic solvents, and the product is more environmentally friendly. DETAILED DESCRIPTION

[0060] Example 1, Comparative Examples 1-3

[0061] An EB-cured antibacterial skin-feel wood paint, the components by weight are shown in Table 1:

[0062] Table 1

[0063]

[0064]

[0065] The viscosity of the 6-functionality polyurethane acrylate at 25°C is 55000-75000 mPa·s, the brand is Etercure 6145-100, purchased from Changxing Chemical Industry Co., Ltd.; the viscosity of the 3-functionality polyurethane acrylate at 60°C is 1300-2500 mPa·s, the brand is BIG-3900, purchased from Bige New Material Technology Co., Ltd.

[0066] A method for preparing an EB-cured antibacterial skin-feel wood paint comprises the following steps:

[0067] S1. Add polyurethane acrylate and reactive diluent in sequence, and stir and disperse at 800 rpm for 15 minutes to make them completely dispersed;

[0068] S2, then add acrylic leveling agent and light stabilizer, continue to stir and disperse at 800 rpm for 10 minutes to make it completely dispersed;

[0069] S3, then add matte powder and photoinitiator, continue stirring and dispersing at 1000 rpm for 20 min, and control the particle fineness in the system to 20 μm;

[0070] S4. Add radiation curing leveling agent, antibacterial agent and silicone leveling agent, continue stirring and dispersing at 800 rpm for 10 minutes to make it completely dispersed, and then cool to room temperature (25° C.).

[0071] An application of an EB-cured antibacterial skin-feel wood paint is applied to the coating of melamine boards, and the coating steps are:

[0072] 1) Use roller coating to evenly apply a layer of UV yellowing resistant adhesion primer (H-8022) on the surface of the melamine board, with a coating amount of 20g / m 2 ;

[0073] 2) Use a mercury lamp to semi-dry cure the UV yellowing-resistant adhesion primer after coating, with a curing energy of 200mJ / cm2 , so that the UV yellowing resistant adhesion primer is partially cured;

[0074] 3) Use roller coating to apply two coats of UV yellowing resistant hard primer on the surface of the melamine board, with a coating amount of 25g / m 2 This layer of UV yellowing resistant hard primer has a hardening effect, which can improve the hardness and flatness of subsequent wood paint;

[0075] 4) Use a mercury lamp to semi-cure the coated UV yellowing-resistant sanding primer, with a curing energy of 150mJ / cm 2 , so that the UV yellowing resistant hard primer is partially cured;

[0076] 5) Use roller coating to apply a layer of UV yellowing resistant sanding primer on the surface of the melamine board, with a coating amount of 25g / m 2 This layer of UV yellowing resistant sanding primer has a sanding effect, which can improve the adhesion and flatness of subsequent wood paint;

[0077] 6) Use a mercury lamp to fully cure the UV yellowing resistant sanding primer after coating, and the curing energy is 300mJ / cm 2 , ensure that the UV yellowing resistant sanding primer is fully cured to form a hard coating;

[0078] 7) Use 400# and 600# sandpaper to sand the cured coating respectively;

[0079] 8) Continue to apply the prepared antibacterial skin-feel wood paint by rubber roller coating, with a coating amount of 40 g / m 2 ;

[0080] 9) Use LED light to pre-cure the applied skin-feel topcoat with a curing energy of 100mJ / cm 2 ;

[0081] 10) Use excimer curing technology (172nm) to further cure the pre-cured wood paint to form a matte film with a skin-feeling effect, giving the coating a better touch and visual effect;

[0082] 11) The final coating is fully cured using EB curing agent with an electron beam dose of 80KGy to ensure that the coating is fully cured to form a stable and hard protective film.

[0083] Example 2

[0084] The specific implementation method is the same as that in Example 1; the difference is that the application of the EB-cured antibacterial skin-feel wood paint in Example 2, step 8) is: using the forward and reverse roller coating method, applying the prepared antibacterial skin-feel wood paint twice, the coating amount is 40g / m2 .

[0085] Example 3

[0086] The specific implementation method is the same as that in Example 1; the difference is that the application of the EB-cured antibacterial skin-feel wood paint in Example 3, step 8) is: using a laser roller coating method, applying the prepared antibacterial skin-feel wood paint twice, the coating amount is 35g / m 2 .

[0087] Performance Testing Methods

[0088] The coatings prepared in the examples and comparative examples were subjected to the following performance tests. The test methods are shown in Table 2, and the test data are listed in Tables 3-4.

[0089] Performance test data

[0090] Table 2

[0091]

[0092]

[0093]

[0094] Table 3

[0095]

[0096] Table 4

[0097] luster Antimicrobial Wear-resistant Feel Example 1 3-4° Level I 0.03g without paint film wear-through μs<0.3 Comparative Example 1 3-4° Level I Slight wear of paint film μs<0.3 Comparative Example 2 3-4° Level II 0.03g without paint film wear-through μs<0.3 Comparative Example 3 5-6° Level I 0.03g without paint film wear-through μs<0.6

[0098] According to the results in Table 3, no matter whether rubber roller coating, laser roller coating or forward and reverse roller coating is used, the wood paint provided by the present invention has little difference in the final performance parameters after being cured by EB curing. Therefore, the wood paint provided by the present invention meets the requirements of rubber roller coating, laser roller coating and forward and reverse roller coating.

[0099] According to the results in Table 4, compared with Example 1, after 3EOTMPTA in Comparative Example 1 was replaced with TPGDA, the wear resistance decreased significantly; in Comparative Example 2, the proportion of the antibacterial auxiliary agent KEPUYIN-J139 was reduced, and the antibacterial effect became worse; in Comparative Example 3, the proportion of the main resin was adjusted, and the glossiness increased while the skin feel performance decreased significantly.

Claims

1. An EB-cured antibacterial skin-feel wood paint, characterized in that: The components include, by weight: 40-60 parts of polyurethane acrylate, 20-40 parts of active diluent, 0.5-1 parts of acrylate leveling agent, 0.1-0.5 parts of light stabilizer, 0.1-0.5 parts of photoinitiator, 1-5 parts of radiation curing leveling agent, 1-3 parts of antibacterial agent, 5-10 parts of matting powder and 0.2-1 parts of silicone leveling agent.

2. The EB-cured antibacterial skin-feel wood paint according to claim 1, characterized in that: The polyurethane acrylate includes 6-functionality polyurethane acrylate and 3-functionality polyurethane acrylate.

3. The EB-cured antibacterial skin-feel wood paint according to claim 2, characterized in that: The viscosity of the 6-functionality polyurethane acrylate at 25° C. is 40000-80000 mPa·s; the viscosity of the 3-functionality polyurethane acrylate at 60° C. is 1000-5000 mPa·s.

4. The EB-cured antibacterial skin-feel wood paint according to claim 3, characterized in that: The weight ratio of the 6-functionality polyurethane acrylate to the 3-functionality polyurethane acrylate is 1:(0.5-1.5).

5. The EB-cured antibacterial skin-feel wood paint according to claim 1 or 4, characterized in that: The active diluent includes 3EOTMPTA and HDDA, and the mass ratio of 3EOTMPTA to HDDA is (1-3):

1.

6. The EB-cured antibacterial skin-feel wood paint according to claim 5, characterized in that: The antibacterial agent comprises a guanidine group and a double-chain quaternary ammonium salt in its structure.

7. The EB-cured antibacterial skin-feel wood paint according to claim 6, characterized in that: The added amount of the photoinitiator is not higher than 0.3 wt %.

8. The EB-cured antibacterial skin-feel wood paint according to claim 7, characterized in that: The weight ratio of the radiation curing leveling agent, the acrylic leveling agent and the silicone leveling agent is 1: (0.05-0.4): (0.2-0.6)。 9. A method for preparing the EB-cured antibacterial skin-feel wood paint according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Add polyurethane acrylate and reactive diluent in sequence, and stir to disperse evenly; S2, add acrylic leveling agent and light stabilizer, stir and disperse evenly; S3, add matte powder and photoinitiator, stir and disperse evenly, and control the fineness in the system to ≤20μm; S4. Add radiation curing leveling agent, antibacterial agent and silicone leveling agent, and stir to disperse evenly.

10. An application of the EB-cured antibacterial skin-feel wood paint according to any one of claims 1 to 8, characterized in that: The coating is applied to wood substrates by rubber roller coating, laser roller coating or reverse roller coating.

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