A kind of 3D texture painting UV white ink and preparation method thereof

Abstract

The present invention discloses a 3D texture painting UV white ink. The raw materials for preparing the ink include 10-30% monofunctional polyurethane acrylate, 5-30% multifunctional polyurethane acrylic resin, 30-60% monofunctional acrylic monomer, 0-10% difunctional acrylic monomer, 3-10% initiator, 3-15% white particles, and 3-8% auxiliary agent. The present invention adopts a combination of cyclotrimethylolpropane formal acrylate and acryloylmorpholine as the monofunctional acrylic monomer. When the white ink is subjected to high-thickness 3D printing, there is no odor, and the toughness of the white ink after curing is significantly improved, the brittleness problem of the white ink is solved, and the use effect is excellent. In 3D texture painting printing applications, the ink is printed by multi-nozzle stacking, with small diffusion, high precision, low odor, good flexibility, and no cracking when bent, meeting the application requirements of 3D texture painting.

Description

Technical Field

[0001] The present invention relates to the field of coating compositions, and in particular to a 3D texture painting UV white ink and a preparation method thereof. Background Art

[0002] As people's living standards improve, they are no longer satisfied with single, flat patterns in oil paintings, wallpaper, and textured artworks. The use of 3D technology, which can enhance the texture of artworks, is becoming increasingly popular. The 3D effect in paintings is primarily achieved through the stacking of white ink, achieved through the 3D printer's multiple nozzles, multiple times, and reciprocating printing. To further enhance the texture of paintings, higher requirements are placed on the accuracy, odor, and thickness of the paintings. In addition to optimizing nozzle accuracy, higher requirements are also placed on the odor, leveling, and diffusion of the printed ink. Existing inks retain a significant amount of odor in the product as the thickness increases. Products with fast curing speeds are prone to shrinkage and curling, while those with slow curing speeds are prone to cracking when bent, and are not resistant to low temperatures. Therefore, it is crucial to develop a 3D white ink that cures quickly, has low odor, and does not curl, bend, or crack.

[0003] Chinese invention patent CN117106337A discloses a method for preparing a highly printable starch-based 3D printing ink. The method uses natural starch as a raw material, which is modified with methacrylic anhydride to self-crosslink under ultraviolet light, forming a network structure. This is then compounded with natural starch and high-amylose starch to create a highly printable starch-based 3D printing ink. The ink exhibits controllable photosensitivity, easy extrusion, and high formability, but is also brittle and prone to cracking when bent. Chinese invention patent CN110655824A discloses a novel bio-ink. Using an acrylate emulsion binder and an aqueous polyurethane acrylate binder, this polyurethane aqueous dispersion exhibits rheological properties suitable for 3D printing, including good modulus and shear thinning, as well as good mechanical properties that do not affect cellular bioactivity. However, it is not suitable for printing with painted materials. Summary of the Invention

[0004] In order to develop a 3D white ink with fast curing speed, low odor, and no curling, bending or cracking, the first aspect of the present invention provides a 3D texture painting UV white ink. The preparation raw materials include, by weight percentage, 10-30% monofunctional polyurethane acrylate, 5-30% multifunctional polyurethane acrylic resin, 30-60% monofunctional acrylic monomer, 0-10% difunctional acrylic monomer, 3-10% initiator, 3-15% white particles, and 3-8% additives.

[0005] As a preferred embodiment, the ratio of the number of propylene double bond groups to the carbamate groups in the monofunctional polyurethane acrylate is 1:(1-3), and the mass of the carbamate groups in the monofunctional polyurethane acrylate accounts for 10-30% of the mass of the monofunctional polyurethane acrylate.

[0006] As a preferred embodiment, the ratio of the number of propylene double bond groups to the number of urethane groups in the monofunctional polyurethane acrylate is 1:1.

[0007] As a preferred embodiment, the monofunctional polyurethane acrylate is 2-[[(butylamino)-carbonyl]oxy]ethyl 2-acrylate, CAS number 63225-53-6.

[0008] As a preferred embodiment, the structural formula of the monofunctional polyurethane acrylate is as follows:

[0009]

[0010] As a preferred embodiment, the multifunctional polyurethane acrylic resin has a weight average molecular weight of 800-5000 Da and a viscosity of 15-30 Pa·s at 23° C.

[0011] As a preferred embodiment, the multifunctional polyurethane acrylic resin is selected from one or a combination of BASF 9033 and Sartomer SR9051.

[0012] As a preferred embodiment, the multifunctional polyurethane acrylic resin is BASF 9033.

[0013] As a preferred embodiment, the monofunctional acrylic monomer is at least one selected from cyclotrimethylolpropane formal acrylate, polyethylene glycol o-phenylphenyl ether acrylate, acryloylmorpholine, and N-vinylcarbazole.

[0014] In the present invention, acrylic monomers such as IBOA, THFA, PHEA, and 4-HBA cannot be used because they have slow curing speeds and strong odors.

[0015] As a preferred embodiment, the monofunctional acrylic monomer is a combination of CTFA (cyclotrimethylolpropane formal acrylate) and ACMO (acryloylmorpholine).

[0016] As a preferred embodiment, the weight ratio of CTFA to ACMO is (9-38): (3.5-25).

[0017] As a preferred embodiment, the weight ratio of CTFA to ACMO is 36.8:3.5.

[0018] As a preferred embodiment, the bifunctional acrylic monomer is selected from at least one of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate.

[0019] As a preferred embodiment, the difunctional acrylic monomer is propoxylated neopentyl glycol diacrylate (PO2NPGDA).

[0020] During experiments, the inventors discovered that using a combination of cyclotrimethylolpropane formal acrylate and acryloylmorpholine as monofunctional acrylic monomers resulted in an odorless white ink for 3D printing, demonstrating excellent performance. The authors speculate that this may be due to the fast curing and low odor nature of these monofunctional acrylic monomers. This results in minimal monomer residue during high-speed inkjet printing, thus preventing the odor of the small-molecule monomers from escaping.

[0021] If white ink prepared with only monofunctional acrylic monomers is printed and cured, the substrate will shrink. By introducing the bifunctional acrylic monomer 1,6-hexanediol diacrylate, the cross-linking density of the ink can be increased, thus avoiding the shrinkage problem after printing.

[0022] However, the applicant further discovered that even at a larger printing thickness, there would be no problem of bending and cracking. The glass transition temperature of cyclotrimethylolpropane formal acrylate and acryloylmorpholine monomer is relatively low, and they are relatively brittle after curing. They are prone to bending and cracking when the thickness increases. This application introduces 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, which is a resin containing both propylene double bond groups and carbamate groups, wherein the content of carbamate groups is relatively high, which can significantly improve the toughness of the white ink after curing, thereby solving the brittleness problem of the white ink.

[0023] However, adding too much ethyl 2-[[(butylamino)carbonyl]oxy]acrylate can reduce the viscosity of the white ink, leading to poor stability and reduced printing precision during stacked printing. A controlled weight ratio of ethyl 2-[[(butylamino)carbonyl]oxy]acrylate to multifunctional polyurethane acrylate resin of (10-30):(5-30) is required to achieve the desired ink viscosity while maintaining toughness, suitable for printing at higher thicknesses.

[0024] As a preferred embodiment, the white particles are selected from at least one of titanium dioxide, silicon dioxide, zinc oxide, zirconium oxide, and aluminum oxide.

[0025] As a preferred embodiment, the white particles are titanium dioxide.

[0026] As a preferred embodiment, the initiator is a photoinitiator, and the photoinitiator is selected from at least one of TPO, 819, TPOL and derivatives thereof.

[0027] As a preferred embodiment, the initiator is TPO.

[0028] As a preferred embodiment, the auxiliary agent includes at least one of a dispersant, a leveling agent, an inhibitor, and a defoaming agent.

[0029] As a preferred embodiment, the dispersant includes but is not limited to Lubrizol 36000; the leveling agent includes but is not limited to BYK 361N; and the polymerization inhibitor includes but is not limited to RAHN UV16.

[0030] A second aspect of the present invention provides a method for preparing a 3D texture painting UV white ink, comprising the following steps:

[0031] S1: white particles, dispersant, and monofunctional acrylic monomer are mixed, stirred evenly, added to a grinder, and ground, and filtered to obtain a white color paste;

[0032] S2: Monofunctional polyurethane acrylate, multifunctional polyurethane acrylate, bifunctional acrylic monomer, initiator, and white color paste are mixed and stirred evenly, and filtered to obtain 3D texture painting UV white ink.

[0033] As a preferred embodiment, the prepared 3D texture painting UV white ink has a viscosity of 40-150 cps at 25° C. and a surface tension of 28-34 mN / m.

[0034] As a preferred embodiment, the aperture of the sieve used for filtration in step S1 is 0.45 μm; the aperture of the sieve used for filtration in step S2 is 0.45 μm.

[0035] As a preferred embodiment, the prepared UV white ink is used in high-viscosity nozzle inkjet printers such as Starlight, Xaar, and Xerox.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The 3D texture painting UV white ink of the present invention uses a combination of cyclotrimethylolpropane formal acrylate and acryloylmorpholine as a monofunctional acrylic monomer. The white ink formed has no odor when performing high-thickness 3D printing and has excellent use effect.

[0038] (2) The 3D texture painting UV white ink of the present invention can increase the cross-linking density of the ink curing by introducing 1,6-hexanediol diacrylate bifunctional acrylic monomer, thereby avoiding the shrinkage problem after printing.

[0039] (3) The 3D texture painting UV white ink of the present invention can significantly improve the toughness of the white ink after curing by introducing 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, thereby solving the brittleness problem of the white ink and improving the low-temperature resistance.

[0040] (4) In the 3D texture painting UV white ink of the present invention, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate and multifunctional polyurethane acrylic resin are prepared in a weight ratio of (10-30):(5-30), which ensures the toughness of the ink after curing. At the same time, the ink has moderate viscosity and is suitable for higher printing thickness.

[0041] (5) The 3D texture painting UV white ink of the present invention, in the 3D texture painting printing application, the ink is printed by stacking multiple nozzles, with small diffusion, high precision, low odor, good flexibility, and no cracking when bent, meeting the application requirements of 3D texture painting. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the back view of the 3D texture painting UV white ink prepared in Example 1;

[0043] Figure 2 This is a front view of the 3D texture painting UV white ink prepared in Example 1;

[0044] Figure 3 This is the back view of the 3D texture painting UV white ink prepared in Comparative Example 1;

[0045] Figure 4 This is a front view of the 3D texture painting UV white ink prepared in Comparative Example 1;

[0046] Figure 5 This is a test image of the bending effect of the 3D texture painting UV white ink prepared in Example 1;

[0047] Figure 6 This is a test chart of the bending effect of the 3D texture painting UV white ink prepared in comparative example 3. DETAILED DESCRIPTION

[0048] Example

[0049] A 3D texture painting UV white ink, the preparation raw materials are shown in Table 1 below in terms of weight percentage.

[0050] Table 1

[0051]

[0052] Comparative Example

[0053] A 3D texture painting UV white ink, the preparation raw materials are shown in Table 2 below in terms of weight percentage.

[0054] Table 2

[0055]

[0056]

[0057] A method for preparing UV white ink for 3D texture painting, comprising the following steps:

[0058] S1: white particles, dispersant, and monofunctional acrylic monomer are mixed, stirred evenly, added to a grinder, and ground, and filtered through a 0.45 μm mesh to obtain a white color paste;

[0059] S2: Monofunctional polyurethane acrylate, multifunctional polyurethane acrylate, difunctional acrylic monomer, initiator, and white color paste are mixed and stirred evenly, and filtered through a 0.45 μm mesh to obtain 3D texture painting UV white ink.

[0060] The back of the 3D texture painting prepared in Example 1 is flat and has little odor after printing with UV white ink; Figure 1 , 2. The 3D texture painting prepared in Example 1 has good bending resistance after printing with UV white ink, and will not crack even if the thickness increases and it is folded in half. Figure 5 .

[0061] The 3D texture painting UV white ink printed in Comparative Example 1 had warping, uneven backside, and strong odor. Figure 3 , 4.

[0062] The 3D texture painting prepared in comparative example 3, printed with UV white ink, is prone to cracking after bending. Figure 6 .

[0063] Performance Testing

[0064] 1. Odor test: Using a single XAAR 2002 printhead with a 12W UV lamp and a printhead speed of 0.5m / s, print a 10x10cm color block 20 times on wallpaper with a print thickness of 3±0.3mm. After printing and letting the finished product sit for 12 hours, smell it for any noticeable unpleasant odor. If no odor is detected, it is considered OK; otherwise, it is considered NG.

[0065] 2. Flexibility test: Using a single XAAR 2002 printhead with a 12W UV lamp and a printhead speed of 0.5m / s, print a 10×10cm color block 20 times on wallpaper with a print thickness of 3±0.3mm. After printing and leaving it for 12 hours, bend it 180° and fold it in half twice. If there is no cracking, it is considered OK; otherwise, it is considered NG.

[0066] 3. Curling test: Using a single XAAR 2002 printhead with a 12W UV lamp and a printhead speed of 0.5m / s, print 10cm high uppercase letters ABCD 20 times on wallpaper with a print thickness of 3±0.3mm. After printing and leaving the back side for 12 hours, if there is no shrinkage or wrinkling, it is considered OK; otherwise, it is considered NG.

[0067] 4. Viscosity: Use a rotational viscometer to test the viscosity.

[0068] The test results are shown in Table 3.

[0069] Table 3

[0070] Viscosity / cps odor flexibility crimping Example 1 125.6 OK OK OK Example 2 82.3 OK OK OK Example 3 65.8 OK OK OK Example 4 99.9 OK OK OK Example 5 56.5 OK OK OK Comparative Example 1 131.4 NG OK NG Comparative Example 2 152.2 NG OK NG Comparative Example 3 135.2 OK NG OK Comparative Example 4 117 OK NG NG Comparative Example 5 79.8 OK NG OK

Claims

1. A 3D texture painting UV white ink, characterized by: The raw materials for the preparation include, by weight percentage, 10-30% of monofunctional polyurethane acrylate, 5-30% of multifunctional polyurethane acrylic resin, 30-60% of monofunctional acrylic monomer, 4.7-10% of difunctional acrylic monomer, 3-10% of initiator, 3-15% of white particles and 3-8% of auxiliary agent; The monofunctional polyurethane acrylate is 2-[[(butylamino)-carbonyl]oxy]ethyl 2-acrylate; The multifunctional polyurethane acrylic resin is BASF 9033; The monofunctional acrylic monomer is a combination of cyclotrimethylolpropane formal acrylate and acryloylmorpholine; The bifunctional acrylic monomer is selected from at least one of 1,6-hexanediol diacrylate and propoxylated neopentyl glycol diacrylate.

2. The 3D texture painting UV white ink according to claim 1, characterized in that: The multifunctional polyurethane acrylic resin has a weight average molecular weight of 800-5000 Da and a viscosity of 15-30 Pa·s at 23° C.

3. The 3D texture painting UV white ink according to claim 1, characterized in that: The white particles are selected from at least one of titanium dioxide, silicon dioxide, zinc oxide, zirconium oxide, and aluminum oxide.

4. The 3D texture painting UV white ink according to claim 1, characterized in that: The auxiliary agent includes at least one of a dispersant, a leveling agent, an inhibitor, and a defoaming agent.

5. A method for preparing the 3D texture painting UV white ink according to claim 4, characterized in that: The following steps are involved: S1: white particles, dispersant, and monofunctional acrylic monomer are mixed, stirred evenly, added to a grinder, and ground, and filtered to obtain a white color paste; S2: Monofunctional polyurethane acrylate, multifunctional polyurethane acrylic resin, bifunctional acrylic monomer, initiator, and white color paste are mixed and stirred evenly, and filtered to obtain 3D texture painting UV white ink.

6. The method for preparing 3D texture painting UV white ink according to claim 5, characterized in that: The prepared 3D texture painting UV white ink has a viscosity of 40-150 cps at 25° C. and a surface tension of 28-34 mN / m.

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