3D texture picture UV white ink and preparation method thereof

Abstract

The invention discloses 3D texture picture UV white ink, which is prepared from the following raw materials in percentage by weight: 10 to 30 percent of monofunctional polyurethane acrylate, 5 to 30 percent of polyfunctional polyurethane acrylic resin, 30 to 60 percent of monofunctional acrylic monomer, 0 to 10 percent of bifunctional acrylic monomer, 3 to 10 percent of initiator, 3 to 15 percent of white particles and 3 to 8 percent of assistant. The composition of cyclotrimethylolpropane methylal acrylate and acryloylmorpholine is adopted as the monofunctional acrylic monomer, when the formed white ink is used for high-thickness 3D printing, peculiar smell is avoided, the toughness of the white ink after curing is obviously improved, the brittleness problem of the white ink is solved, and the use effect is excellent. In the 3D texture picture printing application, the ink is printed through multiple nozzles in a stacked mode, diffusion is small, precision is high, meanwhile, smell is low, flexibility is good, cracking is avoided when the ink is bent, and the application requirement of the 3D texture picture is met.

Description

Technical Field

[0001] The 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] With the improvement of people's living standards, people are no longer satisfied with single flat patterns for oil paintings, wallpapers, and texture paintings. The use of 3D technology can increase the texture of painting artworks and is becoming more and more popular. The 3D effect in painting is mainly achieved through the stacking of white ink, and the desired effect is achieved through the multi-nozzle, multi-time, and reciprocating printing of the 3D printer. In order to further improve the texture of the painting, higher requirements are put forward for the accuracy, odor, and thickness of the painting. In addition to optimizing the accuracy of the nozzle, higher requirements are also put forward for the odor and leveling diffusion of the printing ink. After the thickness of the existing ink increases, a large amount of odor will remain in the product. There are problems such as the fast-curing products are prone to shrinkage and curling, the slow-curing products are prone to bending and cracking, and they are not resistant to low temperatures. Therefore, it is very important to develop a 3D white ink with fast curing speed, low odor, no curling, no bending and cracking.

[0003] Chinese invention patent CN117106337A discloses a method for preparing a starch-based 3D printing ink suitable for high printability, wherein natural starch is selected as raw material, the starch is modified by methacrylic anhydride, and self-crosslinking occurs under ultraviolet light to form a network structure, which is compounded with natural starch and high-amylose starch to prepare a starch-based 3D printing ink suitable for high printability, which has the characteristics of photosensitive controllability, easy extrusion, and high formability, but has high brittleness and is easy to crack when bent. Chinese invention patent CN110655824A discloses a new type of biological ink, which is a polyurethane aqueous dispersion with rheological properties suitable for 3D printing, good modulus and shear thinning, and good mechanical properties, and will not affect the biological activity of cells, but is not suitable for printing of painting preparations. Summary of the invention

[0004] In order to develop a 3D white ink with fast curing speed, low odor, no curling, no bending and 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 number of 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 weight average molecular weight of the multifunctional polyurethane acrylic resin is 800-5000 Da, and the viscosity at 23° C. is 15-30 Pa·s.

[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 implementation, 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, acryloyl morpholine, and N-vinyl carbazole.

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

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

[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] The inventors found in the experiment that the combination of cyclotrimethylolpropane methylal acrylate and acryloyl morpholine as monofunctional acrylic monomers can form a white ink with no odor and excellent use effect when used for 3D printing. The possible reason is that the monofunctional acrylic monomers of cyclotrimethylolpropane methylal acrylate and acryloyl morpholine have fast curing speed and low odor. During high-speed inkjet printing, the monomer residue is small, thereby avoiding the dissipation of odor of small molecular monomers.

[0021] If only white ink prepared with monofunctional acrylic monomers is used for printing and curing, the substrate will shrink. By introducing 1,6-hexanediol diacrylate difunctional acrylic monomer, the cross-linking density of the ink can be increased to avoid 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, while cyclotrimethylolpropane methyl acrylate and acryloylmorpholine monoacrylate have a lower glass transition temperature and are more brittle after curing. They are prone to bending and cracking after the thickness increases. In this application, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate is introduced, which is a resin containing both propylene double bond groups and carbamate groups, wherein the content of carbamate groups is relatively high, and can significantly improve the toughness of the white ink after curing, thereby solving the brittleness problem of the white ink.

[0023] However, when the amount of 2-[[(butylamino)carbonyl]oxy]ethyl acrylate added is too large, the viscosity of the white ink will decrease, the stability will be poor during stacking printing, and the printing accuracy will decrease. It is necessary to control the weight ratio of 2-[[(butylamino)carbonyl]oxy]ethyl acrylate to multifunctional polyurethane acrylic resin to (10-30): (5-30) to ensure the toughness and moderate ink viscosity for higher printing thickness.

[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 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 into a grinder for grinding, 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 implementation, the aperture of the sieve used for filtering in step S1 is 0.45 μm; the aperture of the sieve used for filtering 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 adopts a combination of cyclotrimethylolpropane methyl acrylate and acryloyl morpholine as a monofunctional acrylic monomer. The formed white ink 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 and avoid the shrinkage problem after printing by introducing 1,6-hexanediol diacrylate bifunctional acrylic monomer.

[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 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 a 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, has small diffusion, high precision, low odor, good flexibility, and does not crack when bent, thus 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 diagram of the bending effect of the 3D texture painting UV white ink prepared in Example 1;

[0047] Figure 6 This is a test diagram 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 3D texture painting UV white ink, comprising the following steps:

[0058] S1: white particles, dispersant and monofunctional acrylic monomer are mixed, stirred evenly and then added into a grinder for grinding, 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 UV white ink printed by Example 1 is flat and has little odor; Figure 1 , 2. The 3D texture painting UV white ink prepared in Example 1 has good bending resistance after printing, 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 prepared in Comparative Example 1 was warped after printing, the back was uneven, and there was a strong odor. Figure 3 , 4.

[0062] The 3D texture painting prepared in Comparative Example 3 with UV white ink is prone to cracking after bending. Figure 6 .

[0063] Performance Testing

[0064] 1. Odor test: Use a single XAAR 2002 printhead for printing, the UV lamp power is 12W, the printhead moving speed is 0.5m / s, print a 10×10cm color block 20 times, the printing medium is wallpaper, the printing thickness is 3±0.3mm, and after leaving it for 12 hours after printing, smell the finished product to see if there is an obvious unpleasant odor. If there is no unpleasant odor, it is OK, otherwise it is NG.

[0065] 2. Softness test: Use a single XAAR 2002 print head, the UV lamp power is 12W, the print head moving speed is 0.5m / s, print 10×10cm color blocks 20 times, the printing medium is wallpaper, the printing thickness is 3±0.3mm, leave it for 12 hours after printing, bend it 180°, fold it in half twice, if there is no cracking, it is OK, otherwise it is NG.

[0066] 3. Curling test: Use a single XAAR 2002 nozzle for printing, the UV lamp power is 12W, the nozzle moving speed is 0.5m / s, print 10cm high uppercase ABCD letters 20 times, the printing medium is wallpaper, the printing thickness is 3±0.3mm, and after leaving it for 12 hours after printing, observe that if there is no shrinkage or wrinkles on the back side, it is OK, otherwise it is 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 in that: In terms of weight percentage, the raw materials include 10-30% of monofunctional polyurethane acrylate, 5-30% of multifunctional polyurethane acrylic resin, 30-60% of monofunctional acrylic monomer, 0-10% of bifunctional acrylic monomer, 3-10% of initiator, 3-15% of white particles and 3-8% of auxiliary agent.

2. The 3D texture painting UV white ink according to claim 1, characterized in that: The quantity ratio of the acrylic 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.

3. The 3D texture painting UV white ink according to claim 1, characterized in that: The structural formula of the monofunctional polyurethane acrylate is as follows:

4. 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.

5. The 3D texture painting UV white ink according to claim 1, characterized in that: The monofunctional acrylic monomer is at least one selected from cyclotrimethylolpropane formal acrylate, polyethylene glycol o-phenylphenyl ether acrylate, acryloyl morpholine, and N-vinyl carbazole.

6. The 3D texture painting UV white ink according to claim 1, characterized in that: The bifunctional acrylic monomer is at least one selected from 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate.

7. 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.

8. 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.

9. A method for preparing the 3D texture painting UV white ink according to claim 8, characterized in that: The following steps are involved: S1: white particles, dispersant and monofunctional acrylic monomer are mixed, stirred evenly, added into a grinder for grinding, and filtered to obtain a white color paste; 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.

10. The method for preparing 3D texture painting UV white ink according to claim 9, 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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