An LED-curable ink that self-shrinks to form texture and its preparation method

Abstract

This invention belongs to the field of ink technology, specifically relating to an LED-curable ink that self-shrinks to form textures and its preparation method. The self-shrinking texture-forming LED-curable ink comprises the following components by weight percentage: 5-9% photoinitiator, 27-32% tripropylene glycol diacrylate, 18-24% trimethylolpropane triacrylate, 3-7% silicone acrylate, 8-13% modifier, 3-7% pigment, and 5-8% modified nanomaterials, with the balance being polymers; the polymers include epoxy acrylates, polyurethane acrylates, and tetrafunctional acrylate oligomers. The ink prepared by this invention, by adding silicone acrylates, can produce a shrinking effect, spontaneously forming specific texture effects, and is more resistant to harsh environments, showing excellent performance in coated paper packaging materials.

Description

Technical Field

[0001] This invention belongs to the field of ink technology, specifically relating to an LED curable ink that self-shrinks to form texture and its preparation method. Background Technology

[0002] Self-shrinking textured LED-curable ink is an advanced functional ink that can cure rapidly under specific conditions (such as by UV LED light source irradiation) and spontaneously form specific texture effects during the curing process through internal stress or the action of special additives.

[0003] UV LED curable inks have wide applications in the packaging and printing industry, particularly suitable for high-end product packaging and personalized custom packaging. They can be used for packaging boxes and labels of luxury goods, cosmetics, and electronic products, significantly enhancing brand image and product appeal through unique texture effects. Furthermore, they can meet small-batch customization needs, such as limited-edition product packaging and special holiday editions, providing flexible and cost-effective solutions to enhance market competitiveness and customer satisfaction. However, traditional UV inks require two ink sets to produce the shrinkage effect. This type of printing process suffers from high plate-making costs and expensive printing machines, limiting its application to large-volume printing. For small-batch printing, the printing cost is prohibitively high.

[0004] Coated paper is a commonly used material in high-end packaging, widely popular for its excellent printing performance and appearance. However, due to the positioning standards of high-end brands, the inks used in high-end coated paper have higher requirements for properties such as adhesion, gloss, resistance to high and low temperatures, and alcohol resistance, as these characteristics directly affect the performance of the packaging material in actual use and the overall quality of the product. For example: 1. Adhesion: Adhesion refers to the firmness of the ink on the coated paper. If the adhesion is insufficient, the ink may peel off during transportation, storage, or use, resulting in defects on the packaging surface and affecting aesthetics and brand image. Good adhesion ensures that the ink remains stable under various environmental conditions and will not peel off due to friction, scratching, or other external forces. 2. Resistance to high and low temperatures: High-end packaging paper may need to be used in different climates around the world, so it must have good resistance to high and low temperatures. Extreme temperature changes may cause the ink to crack, discolor, or peel off, affecting the overall quality and appearance of the packaging. 3. Alcohol resistance: High-end packaging paper is frequently exposed to various chemicals, such as cleaning agents and disinfectants, among which alcohol is one of the most common solvents. Inks with poor alcohol resistance are easily dissolved or corroded, affecting the appearance of the packaging and the transmission of information. Especially for cosmetics, electronic products, and food packaging, it is essential to ensure that the ink does not fade or peel when in contact with alcohol to guarantee the integrity of the packaging and the clarity of the information.

[0005] CN 111100498 B discloses a UV-LED curable ink and its application. The ink can be used to prepare packaging printing products, but its high and low temperature resistance is poor when used on coated paper. It has excellent folding endurance at room temperature, but poor folding endurance at low temperature, which cannot meet the high requirements of the current market.

[0006] Therefore, there is an urgent need for an LED-curable ink that can self-shrink to form texture and its preparation method. Summary of the Invention

[0007] The purpose of this invention is to provide an LED-curable ink that self-shrinks to form textures and its preparation method. Through formula design, the ink self-shrinks after printing to produce a unique texture.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An LED-curable ink that self-shrinks to form texture comprises the following components by weight percentage: 5-9% photoinitiator, 27-32% tripropylene glycol diacrylate, 18-24% trimethylolpropane triacrylate, 3-7% silicone acrylate, 8-13% modifier, 3-7% pigment, and 5-8% modified nanomaterials, with the balance being polymers; said polymers include epoxy acrylates, polyurethane acrylates, and tetrafunctional acrylate oligomers.

[0010] In a preferred embodiment, the polymer comprises epoxy acrylate, polyurethane acrylate and tetrafunctional acrylate oligomers in a weight ratio of (1.4-1.7):1:(0.3-0.5).

[0011] In a preferred embodiment, the polyurethane acrylate is EBECRYL® 230 from ZINOSURE.

[0012] In a preferred embodiment, the tetrafunctional acrylate oligomer is EBECRYL® 892 polyester resin from Zhanxin Company.

[0013] This invention improves the adhesion of inks to coated paper and its folding resistance by using a specific ratio of epoxy acrylate, polyurethane acrylate, and tetrafunctional acrylate oligomers. By adjusting the proportions of epoxy acrylate, polyurethane acrylate, and tetrafunctional acrylate oligomers, this invention enables the film layer to withstand greater stress during bending or folding without cracking or peeling.

[0014] In a preferred embodiment, the modified nanomaterial is prepared by mixing nano-calcium carbonate, nano-silica, and nano-titanium dioxide and then modifying it with a diamino-functionalized silane.

[0015] In a preferred embodiment, the diamino functional group silane is the silane coupling agent KH602.

[0016] In a preferred embodiment, the weight ratio of the nano-calcium carbonate, nano-silica, and nano-titanium dioxide is (1.2-1.5):(0.5-0.7):1.

[0017] This invention utilizes modified fillers prepared by adding diamino-functionalized silanes to improve the high and low temperature resistance and alcohol resistance of inks. Furthermore, by modifying nanomaterials with diamino-functionalized silanes, this invention enhances the interfacial bonding between nanomaterials and the resin matrix, while simultaneously improving the uniform dispersion of nanomaterials within the resin matrix.

[0018] In a preferred embodiment, the method for preparing the modified nanomaterial includes the following steps:

[0019] (1) Nanoscale calcium carbonate, nanoscale silicon dioxide and nanoscale titanium dioxide are mixed to obtain nanomaterials;

[0020] (2) Mix silane coupling agent KH602, ethanol and water in a weight ratio of 1:3:3 and stir for 15-20 minutes to obtain the modified solution;

[0021] (3) Mix the nanomaterials and the modification liquid at a weight ratio of 1:5, heat to 80-85℃ and stir for 3-4 hours, filter and dry to obtain the modified nanomaterials.

[0022] In a preferred embodiment, the photoinitiator comprises one or both of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone.

[0023] In a preferred embodiment, the photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone.

[0024] In a preferred embodiment, the regulator is an active amine.

[0025] In a preferred embodiment, an LED-curable ink that self-shrinks to form a texture comprises the following components by weight percentage: 4% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 3% 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone, 30% tripropylene glycol diacrylate, 20% trimethylolpropane triacrylate, 5% silicone acrylate, 10% active amine, and the balance being a polymer.

[0026] This invention provides a method for preparing an LED-curable ink that self-shrinks to form texture, comprising the following steps: adding tripropylene glycol diacrylate, trimethylolpropane triacrylate and a polymer sequentially to an initiator, stirring until homogeneous, then adding silicone acrylate, a modifier, a pigment and modified nanomaterials sequentially, stirring until homogeneous, to obtain an LED-curable ink that self-shrinks to form texture.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0028] 1. The curing ink of the present invention contains organosilicon acrylate, which can produce a shrinkage effect and spontaneously form a specific texture effect.

[0029] 2. By adding a specific proportion of polymer, this invention can improve the adhesion of ink to coated paper and its bending resistance.

[0030] 3. The modified filler prepared by adding diamino functional group silane in this invention can improve the high and low temperature resistance and alcohol resistance of ink. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the LED curable ink with self-shrinking texture prepared in Example 1 after curing.

[0032] Figure 2 Packaging paper prepared using the self-shrinking textured LED-curable ink prepared in Example 1. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] All raw materials used in the following embodiments of the present invention are commercially available products:

[0035] The polyurethane acrylate is designated as EBECRIL® 230 by Zhanxin Company.

[0036] The tetrafunctional acrylate oligomer is EBECRIL® 892, a polyester resin from Zhanxin Company.

[0037] Nano calcium carbonate, Shanghai Liangjiang Titanium Dioxide Chemical Products Co., Ltd., model LP400 ink-grade nano active calcium carbonate.

[0038] Nano-silica, Nanjing Tianxing New Materials Co., Ltd., model TSP-H10.

[0039] Nano titanium dioxide, Nanjing Tianxing New Materials Co., Ltd., model TTP-A12.

[0040] Organosilicon acrylate, Guangdong Haohui New Materials Co., Ltd., model CR90822-1.

[0041] Epoxy acrylate, EBECREL 6040.

[0042] Silane coupling agent KH602, Nanjing Pinning Coupling Agent Co., Ltd.

[0043] The active amine is ethylenediamine.

[0044] Example 1

[0045] This embodiment provides an LED-curable ink that self-shrinks to form texture, comprising the following components by weight percentage: 4% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 3% 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone, 30% tripropylene glycol diacrylate, 20% trimethylolpropane triacrylate, 5% silicone acrylate, 10% active amine, 5% pigment, 7% modified nanomaterials, and the balance being polymer.

[0046] The polymer comprises epoxy acrylate, polyurethane acrylate and tetrafunctional acrylate oligomers in a weight ratio of 1.6:1:0.4.

[0047] The preparation method of the modified nanomaterial includes the following steps:

[0048] (1) Nano-calcium carbonate, nano-silica and nano-titanium dioxide in a weight ratio of 1.3:0.6:1 are mixed to obtain nanomaterials;

[0049] (2) Mix silane coupling agent KH602, ethanol and water in a weight ratio of 1:3:3 and stir for 20 min to obtain modified solution;

[0050] (3) Mix the nanomaterials and the modification liquid at a weight ratio of 1:5, heat to 82°C and stir for 3.5 hours, filter and dry to obtain the modified nanomaterials.

[0051] The method for preparing the self-shrinking textured LED curable ink includes the following steps: adding tripropylene glycol diacrylate, trimethylolpropane triacrylate and polymer sequentially to an initiator, stirring until uniform, and then adding organosilicon acrylate, regulator, pigment and modified nanomaterial sequentially, stirring until uniform to obtain the self-shrinking textured LED curable ink.

[0052] Example 2

[0053] This embodiment provides an LED-curable ink that self-shrinks to form texture, comprising the following components by weight percentage: 3% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 5% 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone, 27% tripropylene glycol diacrylate, 24% trimethylolpropane triacrylate, 7% silicone acrylate, 10% active amine, 4% pigment, 6% modified nanomaterials, and the balance being polymer.

[0054] The polymer comprises epoxy acrylate, polyurethane acrylate and tetrafunctional acrylate oligomers in a weight ratio of 1.4:1:0.5.

[0055] The preparation method of the modified nanomaterial includes the following steps:

[0056] (1) Nano-calcium carbonate, nano-silica and nano-titanium dioxide in a weight ratio of 1.3:0.6:1 are mixed to obtain nanomaterials;

[0057] (2) Mix silane coupling agent KH602, ethanol and water in a weight ratio of 1:3:3 and stir for 20 min to obtain modified solution;

[0058] (3) Mix the nanomaterials and the modification liquid at a weight ratio of 1:5, heat to 80°C and stir for 4 hours, filter and dry to obtain the modified nanomaterials.

[0059] The method for preparing the self-shrinking textured LED curable ink includes the following steps: adding tripropylene glycol diacrylate, trimethylolpropane triacrylate and polymer sequentially to an initiator, stirring until uniform, and then adding organosilicon acrylate, regulator, pigment and modified nanomaterial sequentially, stirring until uniform to obtain the self-shrinking textured LED curable ink.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that the polymer is epoxy acrylate.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 1 is that the polymer comprises epoxy acrylate and polyurethane acrylate in a weight ratio of 1.6:1.

[0064] Comparative Example 3

[0065] The difference between this comparative example and Example 1 is that the polymer comprises epoxy acrylate, polyurethane acrylate and tetrafunctional acrylate oligomers in a weight ratio of 1:1:1.

[0066] Comparative Example 4

[0067] The difference between this comparative example and Example 1 is that the modified nanomaterial is prepared by modifying nano-calcium carbonate with a diamino functional group silane.

[0068] The preparation method of the modified nanomaterial includes the following steps:

[0069] (1) Mix silane coupling agent KH602, ethanol and water in a weight ratio of 1:3:3 and stir for 20 min to obtain modified solution;

[0070] (2) Mix nano-calcium carbonate and modification liquid in a weight ratio of 1:5, heat to 82℃ and stir for 3.5h, filter and dry to obtain modified nanomaterials.

[0071] Comparative Example 5

[0072] This comparative example was prepared according to the preparation method of Example 1 in CN 111100498 B, "A UV-LED Curable Ink and Its Application".

[0073] Performance testing

[0074] The LED-curable inks prepared in Examples 1-2 and Comparative Examples 1-5 and 300g of coated paper were placed into a screen printing machine for screen printing and cured by UV-LED lamps. The screen size was 400 mesh and the wire diameter was 0.05 mm. The curing conditions were: light source: 400, energy: 120 mj / cm². Samples were obtained.

[0075] (1) Adhesion test: Use 3M#600 tape and refer to GB / T 9286-2021 cross-cut test.

[0076] (2) Bending resistance test: whether there is any change when bending at 90° at 10℃, and whether the paint film cracks or peels.

[0077] (3) High and low temperature resistance test: (60℃, 3h; -40℃, 3h) Place in the environment for 20 cycles, allow to return to room temperature naturally after the test is completed, check the appearance and perform adhesion test. No cracking or peeling, and the tape should not peel off after being pasted is acceptable; any of the above conditions are unacceptable.

[0078] (4) Alcohol resistance test: A lint-free cloth soaked in anhydrous ethanol is wrapped with rubber in 4 layers. It is 500g force and slides back and forth horizontally 100 times without showing any white. The stroke is 2cm and the frequency is 30 times / min. It is qualified.

[0079] The results are shown in Table 1.

[0080] Table 1 Performance Test Results

[0081] Adhesion Bending resistance test at 25℃ Bending resistance test at 10℃ High and low temperature resistance testing Alcohol resistance test Example 1 Level 0 No cracks, no peeling No cracks, no peeling qualified qualified Example 2 Level 0 No cracks, no peeling No cracks, no peeling qualified qualified Comparative Example 1 Level 1 There are cracks and peeling. There are cracks and peeling. Unqualified Unqualified Comparative Example 2 Level 1 There are cracks, but no peeling. There are cracks and peeling. Unqualified Unqualified Comparative Example 3 Level 1 No cracks, no peeling There are cracks and peeling. Unqualified qualified Comparative Example 4 Level 0 No cracks, no peeling There are cracks and peeling. Unqualified Unqualified Comparative Example 5 Level 0 No cracks, no peeling There are cracks and peeling. Unqualified qualified

[0082] As shown in Table 1, the inks and coated paper prepared in Examples 1-2 of this invention have good adhesion and excellent performance under extreme environmental conditions, which can meet the market requirements for high-grade packaging paper. Figure 1 and Figure 2 It is known that the ink prepared by this invention can shrink on its own to form a texture (also known as a leather texture or glaze), and the packaging paper prepared with it is of excellent quality.

[0083] The polymer described in Comparative Example 1 is epoxy acrylate, which reduces the adhesion of ink to the surface of coated paper and decreases its bending resistance.

[0084] The polymers described in Comparative Example 2 include epoxy acrylate and polyurethane acrylate in a weight ratio of 1.6:1. The ink adhesion on the coated paper surface decreased, and the bending resistance decreased.

[0085] The polymers described in Comparative Example 3 comprised epoxy acrylate, polyurethane acrylate, and tetrafunctional acrylate oligomers in a weight ratio of 1:1:1. The ink adhesion and folding resistance on the coated paper surface decreased. This demonstrates that only by using polymers with specific ratios can the present invention maintain high ink adhesion and excellent folding resistance on the coated paper surface.

[0086] In Comparative Example 4, the modified nanomaterials were prepared using only nano-calcium carbonate, resulting in a decrease in the ink's resistance to high and low temperatures and its alcohol resistance.

[0087] Comparative Example 5 shows that the performance of existing inks under extreme environmental conditions is not ideal. While Comparative Example 5 exhibits good flexural resistance at room temperature, its performance is poor at 10°C, failing to meet the requirements for use in areas with low temperatures. Furthermore, the ink in Comparative Example 5 also shows unsatisfactory high and low temperature resistance at 60°C and -40°C, failing to meet market demands.

[0088] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An LED-curable ink that self-shrinks to form texture, characterized in that, It includes the following components by weight percentage: photoinitiator 5-9%, tripropylene glycol diacrylate 27-32%, trimethylolpropane triacrylate 18-24%, silicone acrylate 3-7%, modifier 8-13%, pigment 3-7%, and modified nanomaterials 5-8%, with the balance being polymer. The polymer comprises epoxy acrylate, polyurethane acrylate and tetrafunctional acrylate oligomers in a weight ratio of (1.4-1.7):1:(0.3-0.5). The modified nanomaterial is prepared by mixing nano-calcium carbonate, nano-silica and nano-titanium dioxide and then modifying it with a diamino functional group silane. The diamino functional group silane is a silane coupling agent KH602. The weight ratio of nano-calcium carbonate, nano-silica and nano-titanium dioxide is (1.2-1.5):(0.5-0.7):

1.

2. The LED-curable ink with self-shrinking texture according to claim 1, characterized in that, The preparation method of the modified nanomaterial includes the following steps: (1) Nanoscale calcium carbonate, nanoscale silicon dioxide and nanoscale titanium dioxide are mixed to obtain nanomaterials; (2) Mix and stir the silane coupling agent KH602, ethanol and water to obtain the modified solution; (3) Mix the nanomaterials and the modified liquid, heat to 80-85℃ and stir for 3-4 hours, filter and dry to obtain the modified nanomaterials.

3. The LED-curable ink for self-shrinking texture formation according to claim 1, characterized in that, The photoinitiator includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone.

4. The LED-curable ink for self-shrinking texture formation according to claim 3, characterized in that, The photoinitiator includes 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-benzyl-2-dimethylamino-1-(4-morpholinylbenzyl)-1-butanone.

5. The LED-curable ink for self-shrinking texture formation according to claim 1, characterized in that, The regulator is an active amine.

6. A method for preparing an LED-curable ink with self-shrinking texture as described in any one of claims 1-5, characterized in that, The process includes the following steps: adding tripropylene glycol diacrylate, trimethylolpropane triacrylate and polymer sequentially to the initiator, stirring until homogeneous, then adding silicone acrylate, regulator, pigment and modified nanomaterial sequentially, stirring until homogeneous, to obtain an LED-curable ink that self-shrinks to form texture.

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