A pine wood oil-encapsulated UV coating, and a preparation method and application thereof

Abstract

The application discloses a pine wood oil sealing UV paint, and raw materials for preparation include, in weight parts, polyurethane acrylate oligomer 6.0-20.0, epoxy acrylate oligomer 8.0-20.0, polyester acrylate oligomer 5.0-21.0, acidic UV material 4.0-6.0, active monomer 15.0-25.0, photoinitiator 3.0-5.0, catalyst 0.8-1.6, filler 15.0-30.0, defoaming agent 0.1-0.3, leveling agent 0.1-0.3, wetting agent 0.1-0.4. The application can solve the film defect problems of pine wood, such as oil oozing, blistering and delamination at 70 DEG C baking, and can improve the adhesion of the pine wood substrate to the coating at high temperature environment and the appearance is excellent.

Description

Technical Field

[0001] This invention relates to a pine wood sealing UV coating, its preparation method and application, and specifically to the field of coating compositions. Background Technology

[0002] Pine wood has a pine scent and is abundant, making it frequently used for furniture. Pine wood contains a large amount of oil, requiring degreasing treatment before furniture making. However, even after degreasing, oil can still seep out at high temperatures, causing blistering or even peeling of the finish on the pine furniture surface, affecting the product's appearance and quality. The oil in pine wood consists of 30% turpentine and 70% rosin. Turpentine's main components are α-pinene and β-pinene, which are liquid at room temperature. Rosin contains resin acids, fatty acids, and rosin anhydride, with a softening point of 72-76℃. Therefore, rosin in pine wood easily seeps out at temperatures around 70℃, causing the "oil seepage" problem. Existing methods to reduce pine wood oil seepage use sealing coatings to increase adhesion between the coating and the pine wood, thus preventing oil seepage. However, relying solely on sealing is not very effective in preventing oil seepage, and the risk of seepage still exists.

[0003] Chinese invention patent CN202111365123.1 discloses a solvent-free UV-curable coating for sealing pine knot oils and its application method. It uses a high molecular weight, high polarity, and high adhesion resin, effectively reducing the dissolution and extraction of oils from the substrate by the paint, thus effectively preventing oils from entering the paint and sealing them. It also reduces the thermal extraction of oils from the substrate during UV curing, maximizing the sealing of oils within the substrate. However, relying solely on sealing has limited effect on oil restriction; at high temperatures, the oils can damage the adhesion between the coating and the substrate, affecting product quality. Chinese invention patent CN201911327493.9 discloses a UV-curable coating for sealing pine turpentine and its preparation method. It uses a water-soluble UV resin, where the hydrophilic groups can bond with the hydroxyl groups in pine wood via hydrogen bonds, and the lipophilic groups can form a good sealing coating with the UV paint, sealing the turpentine within the pine wood. However, the hydrogen bond bonding in the coating is weak, failing to form a strong sealing film. Summary of the Invention

[0004] To prevent resin seepage during high-temperature processing of pine substrates and to improve the adhesion between the coating and the pine substrate, the first aspect of this invention provides a pine wood sealing UV coating. The raw materials, by weight, include: 6.0-20.0 parts of polyurethane acrylate oligomer, 8.0-20.0 parts of epoxy acrylate oligomer, 5.0-21.0 parts of polyester acrylate oligomer, 4.0-6.0 parts of acidic UV material, 15.0-25.0 parts of active monomer, 3.0-5.0 parts of photoinitiator, 0.8-1.6 parts of catalyst, 15.0-30.0 parts of filler, 0.1-0.3 parts of defoamer, 0.1-0.3 parts of leveling agent, and 0.1-0.4 parts of wetting agent.

[0005] In a preferred embodiment, the acid value of the acidic UV material is ≥200 mg KOH / kg.

[0006] In a preferred embodiment, the acidic UV material is selected from one or a combination of several of the following: Photomer 2203 and Photomer 2204 from IGM Corporation, 648-1 and 649 from Chang Hsing Corporation (Taiwan), Miramer SC6630 and Miramer SC6630 from Miramer Corporation, or M221 from Zi Cai Corporation.

[0007] In a preferred embodiment, the polyurethane acrylate oligomer is an aliphatic polyurethane acrylate oligomer with a functionality ≤6.

[0008] In a preferred embodiment, the aliphatic polyurethane acrylate oligomer with a functionality of ≤6 is selected from one or a combination of several of the following from Chang Hsing Corporation of Taiwan: 6145-100, 6150-100, 6161-100, 6170-100, DR-U198, and DR-U381.

[0009] In a preferred embodiment, the epoxy acrylate oligomer is a difunctional epoxy acrylate oligomer; the polyester acrylate oligomer is selected from one or a combination of several difunctional, trifunctional, and tetrafunctional polyester acrylate oligomers.

[0010] In a preferred embodiment, the bifunctional epoxy acrylate oligomer is selected from one or a combination of several of the following: 621A-80, 623A-80, and 6215-100 from Chang Hsing Corporation of Taiwan, or PE240, EA2235, and EA2280 from Mei Yuan Corporation.

[0011] In a preferred embodiment, the polyester acrylate oligomer is selected from one or a combination of several of the following: 6340, 6353-1, DR-E504 from Chang Hsing Corporation (Taiwan) or 5400, 5363, 5011 from Heng Kwong Corporation.

[0012] In a preferred embodiment, the active monomer is an acrylate monomer containing a double bond, and the acrylate monomer containing a double bond is selected from one or more of monofunctional, difunctional, trifunctional, and tetrafunctional acrylate monomers containing a double bond.

[0013] In a preferred embodiment, the monofunctional acrylate monomer is HEMA from Miki Corporation or EM70 from Chang Hsing Corporation (Taiwan); the difunctional acrylate monomer is SM623 from Miki Corporation or EM221 from Chang Hsing Corporation (Taiwan); the trifunctional acrylate monomer is SM631 from Miki Corporation or EM235 from Chang Hsing Corporation (Taiwan); and the tetrafunctional acrylate monomer is EM242 or 6420 from Chang Hsing Corporation (Taiwan).

[0014] In a preferred embodiment, the photoinitiator is a free radical photoinitiator, which is selected from one or a combination of several of benzoyl initiators, alkyl phenyl ketone initiators, acyl phosphorus oxide initiators, and benzophenone initiators.

[0015] In a preferred embodiment, the photoinitiator is selected from one or a combination of several of BASF's Irgacure 184, Darocur 1173, Irgacure TPO, Irgacure TPO-L, Irgacure 819 and Darocur BP.

[0016] In a preferred embodiment, the catalyst is a Lewis acid catalyst, preferably selected from one or a combination of several of AlCl3, SbCl3, AlBr3, AlCl3(C2H5)O, and BF3(C2H5)O.

[0017] During the experiment, the applicant discovered that by using high-acid-value UV monomers or resins in conjunction with acidic catalysts, the cationic polymerization of α-pinene, β-pinene, and resin acids in pine resin can be promoted. High-acid-value UV monomers or resins can further promote the catalytic reaction. The prepared coating can cause the pine resin on the surface and inside of pine wood to undergo a polymerization reaction. After the pine resin forms a polymer, its softening point increases to over 150°C, which can solve the problem of pine resin softening and seeping out of the substrate during UV curing and baking tests.

[0018] The applicant further discovered that the double bonds of rosin polymerized by cationic polymerization open up and polymerize with the double bonds of UV coating polymerized by free radical polymerization. The rosin and UV coating form a whole, and the polymerized rosin can act as an anchor for the paint film to penetrate into the pine wood substrate, improve the adhesion between the paint film and the pine wood, and further improve the sealing effect of the UV coating.

[0019] In this application, the weight ratio of acidic UV material to catalyst is (4-6):(0.8-1.6). Under the preferred weight ratio, the polymerized rosin has properties close to that of the coating. During the polymerization process, it can polymerize with the double bonds of the coating to improve the adhesion of the coating. However, if the weight ratio is exceeded, the hardness of the polymerized rosin will change, the polymerization effect with the coating will decrease, and the sealing effect will decline.

[0020] In a preferred embodiment, the particle size of the filler is 400-3000 mesh. Preferably, the filler is selected from one or a combination of several of talc, silica, magnesium aluminum silicate, and bentonite.

[0021] In a preferred embodiment, the particle size of the filler is selected from one or a combination of several of 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1250 mesh, and 3000 mesh. The filler is talc powder. Preferably, the talc powder is purchased from Housheng Company.

[0022] In a preferred embodiment, the defoamer is selected from one or a combination of several of the following: BYK 055, BYK 141, BYK 072 (Germany), TEGO Airex 920, TEGO Airex 990 (Evonik Degussa), and KYOEISHA AC270 (Kyoeisha).

[0023] In a preferred embodiment, the leveling agent is selected from one or a combination of several of the following: BYK UV 3575, BYK UV 3576, BYK 333, BYK358N, Evonik Degussa TEGO Glide 100, and TEGO Flow 425.

[0024] In a preferred embodiment, the wetting agent is selected from one or a combination of several of Evonik Degussa TEGO Rad 2011, TEGO Rad 2300, TEGO Wet 270, and BYK 2009, BYK 378, and BYK 3535. In a preferred embodiment, the...

[0025] A second aspect of the present invention provides a method for preparing a pine wood sealing UV coating, comprising the following steps:

[0026] The raw materials are mixed according to their weight proportions and dispersed at a speed of 1300-1700 r / min for 20-30 min to obtain the final product.

[0027] In a preferred embodiment, the prepared pine wood sealing UV coating has a rotational viscosity of 3500-5000 cp at 25°C. More preferably, the prepared pine wood sealing UV coating has a rotational viscosity of 3800-5000 cp at 25°C.

[0028] A third aspect of the present invention provides an application of a pine wood sealing UV coating, which is applied to the surface of a pine wood substrate and the coating method is selected from roller coating, brush coating, spray coating, and curtain coating. Preferably, the coating method is roller coating.

[0029] In a preferred embodiment, the curing energy of the prepared pine wood sealing UV coating is 80-120 mJ / cm². 2 The curing method is ultraviolet curing.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The pine wood sealing UV coating of the present invention uses a high acid value UV monomer or resin and an acid catalyst to promote the cationic polymerization of α-pinene, β-pinene and resin acid in pine resin. The softening point of the polymer formed is increased to above 150°C, and the pine resin will not seep out at 70°C.

[0032] (2) The pine wood sealing UV coating of the present invention opens the double bonds of cationic polymerized pine resin, which will polymerize with the double bonds of free radical polymerized UV coating. The pine resin and UV coating form a whole. The polymerized pine resin can act as an anchor for the paint film to penetrate into the pine wood substrate, improve the adhesion between the paint film and the pine wood, and further improve the sealing effect of the UV coating.

[0033] (3) The pine wood sealing UV coating of the present invention uses a single coating to coat the pine wood substrate, which can solve the problems of paint film defects such as "oil seepage", blistering and delamination when the pine wood is baked at 70℃, improve the adhesion between the pine wood substrate and the coating under high temperature environment, and make the appearance excellent. Attached Figure Description

[0034] Figure 1 The image shows the effect after curing of the pine wood sealing UV coating prepared in Example 1, which was applied by roller to a pine wood substrate containing knots.

[0035] Figure 2 The image shows the effect after curing of the pine wood sealing UV coating prepared in Comparative Example 1, which was applied by roller coating onto a pine wood substrate containing knots. Detailed Implementation

[0036] Example 1

[0037] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 11.0 parts polyurethane acrylate oligomer 6145-100, 19.0 parts epoxy acrylate oligomer 621A-80, 12.8 parts polyester acrylate oligomer 6340, 5.0 parts acidic UV material M221, 15.0 parts active monomer SM623, 8.0 parts active monomer SM631, 3.0 parts free radical photoinitiator Omnirad 1173, 0.5 parts catalyst AlCl3, 0.3 parts catalyst SbCl3, 25.0 parts 400 mesh talc powder, 0.1 parts defoamer BYK 055, 0.2 parts leveling agent BYK UV 3575, and 0.1 parts wetting agent TEGO Rad 2011.

[0038] A method for preparing a UV-cured sealing coating for pine wood includes the following steps:

[0039] The raw materials are mixed according to the weight parts and dispersed at a speed of 1500 r / min for 20 min to obtain the final product.

[0040] The Brookfield rotational viscometer measured a viscosity of 4500 cp at 25°C.

[0041] A UV coating for sealing pine wood was prepared by roller coating on a pine wood substrate containing knots. The cured result is shown in the image below. Figure 1 .

[0042] Example 2

[0043] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 17.0 parts polyurethane acrylate oligomer 6150-100, 15.0 parts epoxy acrylate oligomer 623A-80, 16.5 parts polyester acrylate oligomer 6353-1, 4.0 parts acidic UV material Photomer 2204, 16.0 parts active monomer EM235, 6.0 parts active monomer HEMA, 4.0 parts free radical photoinitiator Omnirad 184, 1.0 part catalyst AlCl3, 20.0 parts 800 mesh talc powder, 0.2 parts defoamer BYK 141, 0.1 parts leveling agent BYK UV 3576, and 0.2 parts wetting agent TEGO Rad 2300.

[0044] A method for preparing a pine wood sealing UV coating is the same as in Example 1.

[0045] The Brookfield rotational viscometer measured a viscosity of 3800 cp at 25°C.

[0046] Example 3

[0047] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 20.0 parts polyurethane acrylate oligomer 6161-100, 20.0 parts epoxy acrylate oligomer 6215-100, 17.5 parts polyester acrylate oligomer DR-E504, 5.0 parts acidic UV material Photomer 2203, 7.0 parts active monomer SM623, 10.0 parts active monomer EM242, 3.5 parts free radical photoinitiator Omnirad MBF, 1.0 part catalyst AlCl3(C2H5)O, 0.5 parts catalyst SbCl3, 15.0 parts 1000 mesh talc powder, 0.1 part defoamer BYK 072, 0.3 parts leveling agent BYK 333, and 0.1 part wetting agent TEGO 270.

[0048] A method for preparing a pine wood sealing UV coating is the same as in Example 1.

[0049] The Brookfield rotational viscometer measured a viscosity of 5000 cp at 25°C.

[0050] Example 4

[0051] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 15.0 parts polyurethane acrylate oligomer 6170-100, 14.0 parts epoxy acrylate oligomer PE240, 5.7 parts polyester acrylate oligomer 5400, 6.0 parts acidic UV material 649, 23.0 parts active monomer EM221, 2.0 parts free radical photoinitiator Omnirad 1173, 2.0 parts free radical photoinitiator Omnirad TPO, 1.0 part catalyst AlCl-3, 0.6 parts catalyst BF3(C2H5)O, 30.0 parts 1000 mesh talc powder, 0.3 parts defoamer TEGO Airex 920, 0.1 parts leveling agent BYK 358N, and 0.3 parts wetting agent BYK 2009.

[0052] A method for preparing a pine wood sealing UV coating is the same as in Example 1.

[0053] The Brookfield rotational viscometer measured a viscosity of 4000 cp at 25°C.

[0054] Example 5

[0055] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 17.0 parts polyurethane acrylate oligomer DR-U198, 8.0 parts epoxy acrylate oligomer EA2235, 13.0 parts polyester acrylate oligomer 5363, 5.0 parts acidic UV material Miramer SC6630, 25.0 parts active monomer SM631, 3.0 parts free radical photoinitiator Omnirad 184, 2.0 parts free radical photoinitiator Omnirad 819, 0.7 parts catalyst AlCl3, 0.7 parts catalyst AlBr3, 25.0 parts 800 mesh talc powder, 0.1 parts defoamer TEGO Airex 990, 0.1 parts leveling agent TEGO Glide 100, and 0.4 parts wetting agent BYK 378.

[0056] A method for preparing a pine wood sealing UV coating is the same as in Example 1.

[0057] The Brookfield rotational viscometer measured a viscosity of 4300 cp at 25°C.

[0058] Example 6

[0059] A pine wood sealing UV coating, the raw materials for which are prepared by weight include: 6.0 parts polyurethane acrylate oligomer DR-U381, 16.0 parts epoxy acrylate oligomer EA2280, 20.6 parts polyester acrylate oligomer 5011, 5.0 parts acidic UV material Miramer SC1400, 21.0 parts active monomer EM242, 3.0 parts free radical photoinitiator Omnirad MBF, 2.0 parts free radical photoinitiator Omnirad TPO-L, 0.6 parts catalyst AlCl3, 0.2 parts catalyst SbCl3, 25.0 parts 1200 mesh talc powder, 0.2 parts defoamer KYOEISHA 425, 0.2 parts leveling agent TEGO Flow 425, and 0.2 parts wetting agent BYK3535.

[0060] A method for preparing a pine wood sealing UV coating is the same as in Example 1.

[0061] The Brookfield rotational viscometer measured a viscosity of 4750 cp at 25°C.

[0062] Comparative Example 1

[0063] A pine wood sealing UV coating and its preparation method are disclosed. The specific raw materials and preparation method are the same as in Example 1, except that the amount of acidic UV material added is 0 and the amount of catalyst added is 0.

[0064] The viscosity measured at 25°C using a Brookfield rotational viscometer was 4650 cp.

[0065] A UV coating for sealing pine wood was prepared by roller coating on a pine wood substrate containing knots. The cured result is shown in the image below. Figure 2 .

[0066] Comparative Example 2

[0067] A pine wood sealing UV coating and its preparation method are disclosed. The specific raw materials and preparation method are the same as in Example 1, except that the amount of catalyst added is 0.

[0068] The viscosity measured at 25°C using a Brookfield rotational viscometer was 4550 cp.

[0069] Comparative Example 3

[0070] A pine wood sealing UV coating and its preparation method are disclosed. The specific raw materials and preparation method are the same as in Example 1, except that the amount of acidic UV material added is 0.

[0071] The Brookfield rotational viscometer measured a viscosity of 4700 cp at 25°C.

[0072] Comparative Example 4

[0073] A pine wood sealing UV coating and its preparation method are disclosed. The specific raw materials and preparation method are the same as in Example 1, except that the amount of acidic UV material added is 15 parts by weight.

[0074] The Brookfield rotational viscometer measured a viscosity of 4000 cp at 25°C.

[0075] Performance testing

[0076] The pine wood sealing UV coatings prepared in the examples and comparative examples were roller-coated onto pine wood substrates containing knots, with a coating weight of 25 g / m². 2 Turn on the mercury lamp in the UV curing machine and adjust the UVA energy to 100 mJ / cm². 2 After curing, the same amount of coating and curing energy were used to repeat the roller coating process. After baking at 70℃ for 2 hours, the properties are shown in Table 1.

[0077] 1. Appearance: Visually inspect for issues such as oil seepage, bubbling, whitening, and delamination;

[0078] 2. Adhesion: The adhesion between the coating and the pine wood substrate after curing was tested in accordance with GB / T9286-2021 standard.

[0079] Table 1

[0080] Paint film appearance Adhesion / Grade Example 1 No abnormalities Level 1 Example 2 No abnormalities Level 1 Example 3 No abnormalities Level 1 Example 4 No abnormalities Level 1 Example 5 No abnormalities Level 1 Example 6 No abnormalities Level 1 Comparative Example 1 Oily, bubbly, white, peeling Level 5 Comparative Example 2 Oily, bubbly, and white Level 3 Comparative Example 3 Oily, bubbly, white, peeling Level 4 Comparative Example 4 Oily, bubbly, white, peeling Level 5

[0081] As can be seen from the table above, the paint film of Comparative Example 1, which did not contain a catalyst or acidic UV material, exhibited oil seepage, bubbling, whitening, and delamination after baking at 70°C for 2 hours, and its adhesion was very poor, significantly inferior to that of the Example. The paint films of Comparative Examples 2 and 3, which only contained a catalyst or acidic UV material, showed slightly better oil seepage and adhesion than Comparative Example 1 after baking at 70°C for 2 hours, but were still significantly inferior to the Example. Excessive addition of acidic material affected the free radical polymerization of the paint film. Therefore, the paint film of Comparative Example 4, after baking at 70°C for 2 hours, exhibited oil seepage, bubbling, whitening, and delamination, and its adhesion was very poor, significantly inferior to that of the Example.

Claims

1. A pine wood oil seal UV coating, characterized by, The raw materials for preparation, by weight, include: 6.0-20.0 parts of polyurethane acrylate oligomer, 8.0-20.0 parts of epoxy acrylate oligomer, 5.0-21.0 parts of polyester acrylate oligomer, 4.0-6.0 parts of acidic UV material, 15.0-25.0 parts of active monomer, 3.0-5.0 parts of photoinitiator, 0.8-1.6 parts of catalyst, 15.0-30.0 parts of filler, 0.1-0.3 parts of defoamer, 0.1-0.3 parts of leveling agent, and 0.1-0.4 parts of wetting agent; The acidic UV material is selected from one or a combination of several of the following: Photomer 2203 and Photomer 2204 from IGM Corporation, 648-1 and 649 from Chang Hsing Corporation (Taiwan), Miramer SC6630 and Miramer SC1400 from Mei Yuan Corporation, or M221 from Zi Cai Corporation. The catalyst is a Lewis acid catalyst, which is selected from one or a combination of several of AlCl3, SbCl3, AlBr3, AlCl3(C2H5)O, and BF3(C2H5)O.

2. The pine oil seal UV coating according to claim 1, characterized in that, The polyurethane acrylate oligomer is an aliphatic polyurethane acrylate oligomer with a functionality of ≤6.

3. The pine oil seal UV coating according to claim 1, characterized in that, The epoxy acrylate oligomer is a difunctional epoxy acrylate oligomer; the polyester acrylate oligomer is selected from one or a combination of several difunctional, trifunctional, and tetrafunctional polyester acrylate oligomers.

4. The pine oil seal UV coating of claim 1, wherein, The active monomer is an acrylate monomer containing a double bond, and the acrylate monomer containing a double bond is selected from one or more of the monofunctional, difunctional, trifunctional, and tetrafunctional acrylate monomers containing a double bond.

5. The pine oil seal UV coating of claim 1, wherein, The photoinitiator is a free radical photoinitiator, which is selected from one or a combination of several of benzoyl initiators, alkyl phenyl ketone initiators, acyl phosphorus oxide initiators, and benzophenone initiators.

6. The pine oil seal UV coating of claim 1, wherein, The filler has a particle size of 400-3000 mesh and is selected from one or a combination of talc, silica, magnesium aluminum silicate, and bentonite.

7. A process for the preparation of a pine oil blocking UV coating according to any one of claims 1 to 6, characterized in that, Includes the following steps: The raw materials are mixed according to their weight proportions and dispersed at a speed of 1300-1700 r / min for 20-30 min to obtain the final product.

8. Use of a pine oil-free UV coating according to any one of claims 1 to 6, characterized in that, It is applied to the surface of pine wood substrates, and the coating method is selected from one of roller coating, brush coating, spray coating, and curtain coating.

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