High-strength UV ink and preparation method thereof

Abstract

The invention relates to high-strength UV ink and a preparation method thereof, and belongs to the technical field of UV ink. The high-strength UV ink comprises the following components: a modified acrylate emulsion, a reaction monomer, a photoinitiator, a pigment, a defoaming agent and a solvent, wherein the modified acrylate emulsion is prepared by the following steps: uniformly stirring and mixing an emulsifier, sodium bicarbonate, deionized water and 2 / 3 of a composite monomer in a reaction kettle to obtain a mixture; and slowly heating the mixture, adding 1 / 3 of the initiator, slowly adding the rest of the composite monomer and the rest of the initiator, carrying out a constant-temperature water bath reaction, and cooling to obtain the product. By changing the surface activity of the pigment, the dispersity of the pigment in a resin system is improved, the interface bonding force between the pigment and resin is improved, and the adhesion firmness and mechanical strength of the composite ink are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of UV inks, and relates to a high-strength UV ink and a preparation method thereof. Background Art

[0002] Among the resins for UV inks, acrylic resins have become one of the best choices for UV ink binders due to their diversity and good physical and chemical properties. Copolymerization monomers carrying different functional groups can improve some properties of the polymer after participating in the polymerization reaction, such as hydrophilicity / hydrophobicity, low / high temperature resistance, acid / alkali resistance, corrosion resistance, etc. In the emulsion polymerization system, monomers are the most important components, and acrylic monomers generally consist of hard monomers, soft monomers, and functional monomers. The types and dosages of monomers determine the chemical properties, mechanical properties, adhesion properties, anti-fouling properties, antibacterial properties, and construction properties of the polymer emulsion.

[0003] Another key to preparing UV ink lies in the dispersion, stability, and viscosity control of pigments. To obtain high-quality UV ink, it is necessary to improve its dispersion stability. At present, the domestic research on pigment dispersion in UV ink mainly uses a ball mill to prepare color paste from pigments, monomers, and dispersants, and then adds oligomers, monomers, and ink additives. However, the ink prepared by this method has low stability, limited improvement in pigment dispersion, insufficient binding force with the resin, low strength of the ink film, and at the same time, partial aggregation of the pigments also leads to low adhesion of the ink to the substrate. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength UV ink and a preparation method thereof. By changing the surface activity of the pigment, increasing its dispersibility in the resin system, and improving the interfacial binding force between it and the resin, the adhesion firmness and mechanical strength of the composite ink are enhanced.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A high-strength UV ink comprises the following components in parts by weight:

[0007] 20 - 30 parts of modified acrylate emulsion, 50 - 70 parts of reaction monomer, 2 - 4 parts of photoinitiator, 14 - 20 parts of pigment, 2 - 3 parts of defoamer, and 20 - 30 parts of solvent;

[0008] As a preferred technical solution of the present invention, the reaction monomer consists of isobornyl methacrylate and triethylene glycol diacrylate in a mass ratio of 12 - 13:20 - 25.

[0009] As a preferred technical solution of the present invention, the photoinitiator is one or more of 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone, benzoin diethyl ether, and 1 - hydroxycyclohexyl phenyl ketone.

[0010] As a preferred technical solution of the present invention, the pigment is one or more of titanium dioxide, carbon black and aluminum silver paste.

[0011] As a preferred technical solution of the present invention, the defoamer is polydimethylsiloxane. The solvent is one or both of organic solvent and deionized water.

[0012] As a preferred technical solution of the present invention, the modified acrylate emulsion comprises the following components in parts by weight: 60-70 parts of composite monomer, 2-5 parts of emulsifier, 2-3 parts of initiator, 1.8-2.4 parts of sodium bicarbonate and 40-60 parts of deionized water.

[0013] As a preferred technical solution of the present invention, the composite monomer is composed of methyl methacrylate, ethyl acrylate and functional monomer in a mass ratio of 35-45:17-21:5-8; the emulsifier is one or both of emulsifier OP-10 and sodium dodecyl sulfate; the initiator is ammonium persulfate.

[0014] As a preferred technical solution of the present invention, the preparation method of the modified acrylate emulsion comprises the following steps:

[0015] S1. Put the emulsifier, sodium bicarbonate, deionized water and 2 / 3 of the composite monomer into a reaction kettle and stir and mix evenly to obtain a mixed material;

[0016] S2. Slowly heat up the mixed material, add 1 / 3 of the initiator, slowly add the remaining composite monomer and the remaining initiator and carry out a constant temperature water bath reaction, and then cool to obtain the product.

[0017] As a preferred technical solution of the present invention, in step S1, the stirring and mixing is carried out at 200-300 r / min for 20-30 min.

[0018] As a preferred technical solution of the present invention, in step S2, the slow heating is to heat up to 70-80 °C; the constant temperature water bath reaction is to react at 80-90 °C for 3-5 h; the cooling is to cool to room temperature.

[0019] As a preferred technical solution of the present invention, the preparation method of the functional monomer comprises the following steps:

[0020] Step 1. Under a nitrogen atmosphere, put diethylenetriaminepropyltrimethoxysilane and absolute ethanol into a dry reaction kettle and stir and mix, add triethylamine, and then slowly dropwise add glycidol while controlling the temperature and stirring, and remove the solvent by vacuum distillation to obtain an intermediate;

[0021] Step 2. Mix the intermediate, glacial acetic acid and absolute ethanol evenly, add a benzaldehyde derivative and stir at a constant temperature, and then centrifuge to obtain the product.

[0022] As a preferred technical solution of the present invention, in step one, the stirring and mixing is carried out at 120 - 160 r / min for 10 - 15 min; the temperature-controlled stirring is carried out at 50 - 60 °C for 2 - 3 h; the continuous stirring is carried out at 50 - 60 °C for 4 - 6 h; the dosage ratio of diethylenetriaminepropyltrimethoxysilane, absolute ethanol, glycidol and triethylamine is 100 - 110 g : 30 - 34 g : 200 - 230 mL : 1.0 - 1.2 g.

[0023] As a preferred technical solution of the present invention, in step two, the constant-temperature stirring is carried out at 55 - 60 °C for 4 - 6 h; the dosage ratio of the intermediate, glacial acetic acid, absolute ethanol and benzaldehyde derivative is 12 - 15 g : 0.02 - 0.03 g : 22 - 25 mL : 3.4 - 3.8 g; the benzaldehyde derivative is an aromatic aldehyde compound with multiple oxygen-containing functional groups, such as syringaldehyde and vanillin, etc.

[0024] The present invention discloses a preparation method of a high-strength UV ink. The preparation method includes the following steps: stirring a reaction monomer, a photoinitiator, a pigment, an antifoaming agent and a solvent at 300 - 800 r / min for 5 - 10 min, and adding a modified acrylate emulsion and stirring for 10 - 20 min to obtain the ink.

[0025] Advantages of the present invention:

[0026] The present invention prepares a high-strength UV ink including raw materials such as a modified acrylate emulsion, a reaction monomer, a photoinitiator, a pigment, an antifoaming agent and a solvent. The functional monomers in the modified acrylate emulsion endow the ink film with excellent adhesion and mechanical strength. The combination of diethylenetriaminepropyltrimethoxysilane, glycidol and benzaldehyde derivative can change the surface activity of the pigment, increase its dispersibility in the resin system, improve the interfacial bonding force between it and the resin, and enhance the adhesion firmness and mechanical strength of the composite ink.

[0027] The acrylic water-based ink involved in the present invention has excellent mechanical strength characteristics and is not prone to deformation. At the same time, it also has very strong adhesion and can achieve firm bonding with various substrates. Specific embodiments

[0028] To further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific embodiments, structures, features and their effects of the present invention in combination with examples.

[0029] Example 1

[0030] A high-strength UV ink includes the following components by weight:

[0031] 20 parts of modified acrylate emulsion, 50 parts of reactive monomer, 2 parts of photoinitiator, 14 parts of pigment, 2 parts of defoamer and 20 parts of solvent; the reactive monomer is composed of isobornyl methacrylate and triethylene glycol diacrylate according to a mass ratio of 12:20; the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone; the pigment is titanium dioxide; the defoamer is polydimethylsiloxane; the solvent is composed of isopropyl alcohol and deionized water according to a mass ratio of 1:4.

[0032] The modified acrylate emulsion by weight includes the following components: 60 parts of composite monomer, 2 parts of emulsifier, 2 parts of initiator, 1.8 parts of sodium bicarbonate and 40 parts of deionized water;

[0033] The composite monomer is composed of methyl methacrylate, ethyl acrylate and functional monomer according to a mass ratio of 35:17:5; the emulsifier is composed of emulsifier OP-10 and sodium dodecyl sulfate according to a mass ratio of 1.0:1; the initiator is ammonium persulfate;

[0034] The preparation method of the modified acrylate emulsion includes the following steps:

[0035] S1. Put the emulsifier, sodium bicarbonate, deionized water and 2 / 3 of the composite monomer into a reaction kettle and stir at 200 r / min for 20 min to obtain a mixture;

[0036] S2. Slowly heat the mixture to 70 °C, add 1 / 3 of the initiator, slowly add the remaining composite monomer and the remaining initiator, react at 80 °C for 3 h, and cool to room temperature to obtain the product.

[0037] The preparation method of the functional monomer includes the following steps:

[0038] Step 1. Under a nitrogen atmosphere, put diethylenetriaminepropyltrimethoxysilane and absolute ethanol into a dry reaction kettle and stir at 120 r / min for 10 min. After adding triethylamine, slowly dropwise add glycidol and stir at 50 °C for 2 h. Remove the solvent by vacuum distillation to obtain an intermediate; the dosage ratio of diethylenetriaminepropyltrimethoxysilane, absolute ethanol, glycidol and triethylamine is 100 g:30 g:200 mL:1.0 g;

[0039] Step 2. Mix the intermediate, glacial acetic acid and absolute ethanol, add syringaldehyde and stir at 55 °C for 4 h. Centrifuge to obtain a yellow viscous liquid; the dosage ratio of the intermediate, glacial acetic acid, absolute ethanol and syringaldehyde is 12 g:0.02 g:22 mL:3.4 g.

[0040] A preparation method of a high-strength UV ink comprises the following steps: reacting monomers, photoinitiator, pigment, defoamer and solvent are stirred at 300 r / min for 5 min, and then modified acrylate emulsion is added and stirred for 10 min to obtain the ink.

[0041] Example 2

[0042] A high-strength UV ink comprises the following components by weight:

[0043] 25 parts of modified acrylate emulsion, 60 parts of reacting monomer, 3 parts of photoinitiator, 17 parts of pigment, 2.5 parts of defoamer and 25 parts of solvent; the reacting monomer consists of isobornyl methacrylate and triethylene glycol diacrylate in a mass ratio of 12.5:22; the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone; the pigment is titanium dioxide; the defoamer is polydimethylsiloxane; the solvent consists of isopropanol and deionized water in a mass ratio of 1:4.

[0044] The modified acrylate emulsion comprises the following components by weight: 65 parts of composite monomer, 4 parts of emulsifier, 2.5 parts of initiator, 2.1 parts of sodium bicarbonate and 50 parts of deionized water;

[0045] The composite monomer consists of methyl methacrylate, ethyl acrylate and functional monomer in a mass ratio of 40:19:6; the emulsifier consists of emulsifier OP-10 and sodium dodecyl sulfate in a mass ratio of 1.2:1; the initiator is ammonium persulfate;

[0046] The preparation method of the modified acrylate emulsion comprises the following steps:

[0047] S1. An emulsifier, sodium bicarbonate, deionized water and 2 / 3 of the composite monomer are placed in a reaction kettle and stirred at 250 r / min for 25 min to obtain a mixture;

[0048] S2. The mixture is slowly heated to 75 °C, 1 / 3 of the initiator is added, and the remaining composite monomer and the remaining initiator are slowly added, and the reaction is carried out at 85 °C for 4 h and then cooled to room temperature to obtain the modified acrylate emulsion.

[0049] The preparation method of the functional monomer comprises the following steps:

[0050] Step 1. Under a nitrogen atmosphere, diethylenetriaminepropyltrimethoxysilane and absolute ethanol are placed in a dry reaction kettle and stirred at 140 r / min for 12 min. After triethylamine is added, glycidol is slowly added dropwise and stirred at 55 °C for 2.5 h. The solvent is removed by vacuum distillation to obtain an intermediate; the dosage ratio of diethylenetriaminepropyltrimethoxysilane, absolute ethanol, glycidol and triethylamine is 105 g:32 g:215 mL:1.1 g;

[0051] Step 2: Mix the intermediate, glacial acetic acid, and absolute ethanol, add syringaldehyde, stir at 58 °C for 5 h, centrifuge to obtain a yellow viscous liquid; the dosage ratio of the intermediate, glacial acetic acid, absolute ethanol, and syringaldehyde is 14 g: 0.025 g: 24 mL: 3.6 g.

[0052] A preparation method of a high-strength UV ink comprises the following steps: Stir the reaction monomer, photoinitiator, pigment, defoamer, and solvent at 550 r / min for 8 min, add the modified acrylate emulsion, and stir for 15 min to obtain.

[0053] Example 3

[0054] A high-strength UV ink comprises the following components by weight:

[0055] 30 parts of modified acrylate emulsion, 70 parts of reaction monomer, 4 parts of photoinitiator, 20 parts of pigment, 3 parts of defoamer, and 30 parts of solvent; the reaction monomer consists of isobornyl methacrylate and triethylene glycol diacrylate in a mass ratio of 13:25; the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone; the pigment is titanium dioxide; the defoamer is polydimethylsiloxane; the solvent consists of isopropyl alcohol and deionized water in a mass ratio of 1:4.

[0056] The modified acrylate emulsion comprises the following components by weight: 70 parts of composite monomer, 5 parts of emulsifier, 3 parts of initiator, 2.4 parts of sodium bicarbonate, and 60 parts of deionized water;

[0057] The composite monomer consists of methyl methacrylate, ethyl acrylate, and functional monomer in a mass ratio of 45:21:8; the emulsifier consists of emulsifier OP-10 and sodium dodecyl sulfate in a mass ratio of 1.5:1; the initiator is ammonium persulfate;

[0058] The preparation method of the modified acrylate emulsion comprises the following steps:

[0059] S1: Place the emulsifier, sodium bicarbonate, deionized water, and 2 / 3 of the composite monomer in a reaction kettle, stir at 300 r / min for 30 min to obtain a mixed material;

[0060] S2: Slowly heat the mixed material to 80 °C, add 1 / 3 of the initiator, slowly add the remaining composite monomer and the remaining initiator, react at 90 °C for 5 h, and cool to room temperature to obtain.

[0061] The preparation method of the functional monomer comprises the following steps:

[0062] Step 1: Under a nitrogen atmosphere, place diethylenetriaminepropyltrimethoxysilane and absolute ethanol in a dry reaction kettle, stir at 160 r / min for 15 min. After adding triethylamine, slowly dropwise add glycidol and stir at 60 °C for 3 h. Then, remove the solvent by vacuum distillation to obtain an intermediate. The dosage ratio of diethylenetriaminepropyltrimethoxysilane, absolute ethanol, glycidol, and triethylamine is 110 g: 34 g: 230 mL: 1.2 g;

[0063] Step 2: Mix the intermediate, glacial acetic acid, and absolute ethanol, add syringaldehyde and stir at 60 °C for 6 h. Centrifuge to obtain a yellow viscous liquid, which is the product. The dosage ratio of the intermediate, glacial acetic acid, absolute ethanol, and syringaldehyde is 15 g: 0.03 g: 25 mL: 3.8 g.

[0064] A preparation method of a high-strength UV ink includes the following steps: Stir the reaction monomers, photoinitiator, pigment, defoamer, and solvent at 800 r / min for 10 min, and then add a modified acrylate emulsion and stir for 20 min to obtain the ink.

[0065] Comparative Example 1

[0066] Compared with Example 3, the difference in Comparative Example 1 is that glycidol is not used, and the other components, preparation steps, and parameters are the same.

[0067] Comparative Example 2

[0068] Compared with Example 3, the difference in Comparative Example 2 is that syringaldehyde is not used, and the other components, preparation steps, and parameters are the same.

[0069] Comparative Example 3

[0070] Compared with Example 3, the difference in Comparative Example 3 is that silane coupling agent KH550 is used instead of diethylenetriaminepropyltrimethoxysilane, and the other components, preparation steps, and parameters are the same.

[0071] Comparative Example 4

[0072] Compared with Example 3, the difference in Comparative Example 4 is that silane coupling agent KH570 is used instead of diethylenetriaminepropyltrimethoxysilane, and the other components, preparation steps, and parameters are the same.

[0073] Comparative Example 5

[0074] Compared with Example 3, the difference in Comparative Example 5 is that ethyl acrylate is used instead of the functional monomer, and the other components, preparation steps, and parameters are the same.

[0075] The inks prepared in Examples 1 - 3 and Comparative Examples 1 - 5 were respectively subjected to the following tests, and the test results are shown in Table 1.

[0076] Adhesion test: According to GB / T13217.7-2009, using PET film as the substrate and selecting 3M tape;

[0077] Tensile strength test: GB / T1040.1-2018;

[0078] Table 1

[0079]

[0080]

[0081] From the test results in Table 1, it can be seen that compared with Comparative Examples 1-5, in Examples 1-3 of the present invention, by using diethylenetriaminepropyltrimethoxysilane, Si-O-Ti chemical bonds can be formed on the surface of inorganic pigments (titanium dioxide), enhancing the interfacial bonding between the resin and the pigment. The amino group at its end reacts with the carboxyl group in the acrylate and the epoxy group of glycidyl, promoting the chemical bonding between the organic and inorganic phases, reducing interfacial defects. At the same time, the flexible long chain of the silane can moderately improve the toughness of the ink film, enhance the cross-linking effect to increase the network density, and improve the tensile strength; the highly polar epoxy group of glycidyl can improve the wettability of the ink film to the substrate and enhance physical adsorption; the epoxy group participates in curing cross-linking, increasing the cross-linking density of the polymer, making the ink film structure more dense and significantly enhancing the mechanical strength; the aldehyde group of the benzaldehyde derivative forms a Schiff base structure with the amino group in diethylenetriaminepropyltrimethoxysilane, and its oxygen-containing functional group can provide additional cross-linking points, strengthening the chemical anchoring between the ink film and the substrate. The oxygen-containing functional group and the Schiff base structure can also adsorb pigments through forces such as hydrogen bonding and electrostatic adsorption, increasing the dispersibility of the pigments and reducing their agglomeration; the rigid benzene ring structure of the benzaldehyde derivative increases the network rigidity and improves the tensile strength.

[0082] In the present invention, a main cross-linking skeleton is formed by diethylenetriaminepropyltrimethoxysilane and glycidol, and syringaldehyde is introduced as a secondary cross-linking point to construct a multi-level network structure, improving the mechanical strength and adhesion of the ink film; through the silane bridging the inorganic pigment and the resin, and glycidol and syringaldehyde enhancing the cohesive energy of the resin, the interfacial stress is reduced together, improving the overall performance.

[0083] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any indirect modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A high-strength UV ink, characterized in that, It comprises the following components by weight parts: 20 - 30 parts of modified acrylate emulsion, 50 - 70 parts of reactive monomer, 2 - 4 parts of photoinitiator, 14 - 20 parts of pigment, 2 - 3 parts of defoamer and 20 - 30 parts of solvent; Among them, the preparation method of the modified acrylate emulsion comprises the following steps: S1. Put the emulsifier, sodium bicarbonate, deionized water and 2 / 3 of the composite monomer into a reaction kettle, stir and mix evenly to obtain a mixture; S2. Slowly heat up the mixture, add 1 / 3 of the initiator, slowly add the remaining composite monomer and the remaining initiator, and carry out a constant temperature water bath reaction, then cool to obtain.

2. A high-strength UV ink according to claim 1, wherein: The reactive monomer is composed of isobornyl methacrylate and triethylene glycol diacrylate according to the mass ratio of 12 - 13:20 - 25; the photoinitiator is one or more of 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone, benzoin diethyl ether and 1 - hydroxycyclohexyl phenyl ketone.

3. The high-strength UV ink according to claim 1, characterized in that: The pigment is one or more of titanium dioxide, carbon black and aluminum silver paste; the solvent is one or two of organic solvent and deionized water.

4. The high-strength UV ink according to claim 1, characterized in that: The modified acrylate emulsion comprises the following components by weight parts: 60 - 70 parts of composite monomer, 2 - 5 parts of emulsifier, 2 - 3 parts of initiator, 1.8 - 2.4 parts of sodium bicarbonate and 40 - 60 parts of deionized water.

5. A high-strength UV ink according to claim 4, characterized in that: The composite monomer is composed of methyl methacrylate, ethyl acrylate and functional monomer according to the mass ratio of 35 - 45:17 - 21:5 - 8; the emulsifier is one or two of emulsifier OP - 10 and sodium dodecyl sulfate.

6. The high-strength UV ink according to claim 1, wherein: In step S1, the stirring and mixing is carried out at 200 - 300 r / min for 20 - 30 min; in step S2, the slow heating up is to heat up to 70 - 80 °C; the constant temperature water bath reaction is carried out at 80 - 90 °C for 3 - 5 h; the cooling is to cool to room temperature.

7. A high-strength UV ink according to claim 1, characterized in that, The preparation method of the functional monomer comprises the following steps: Step 1. Under a nitrogen atmosphere, put diethylenetriaminepropyltrimethoxysilane and absolute ethanol into a dry reaction kettle, stir and mix, after adding triethylamine, slowly dropwise add glycidyl while controlling the temperature and stirring, and remove the solvent by reduced pressure distillation to obtain an intermediate; Step 2. Mix the intermediate, glacial acetic acid and absolute ethanol evenly, add the benzaldehyde derivative and stir at a constant temperature, then centrifuge to obtain.

8. The high-strength UV ink according to claim 7, wherein: In step 1, the stirring and mixing is carried out at 120 - 160 r / min for 10 - 15 min; the temperature - controlled stirring is carried out at 50 - 60 °C for 2 - 3 h; the continuous stirring is carried out at 50 - 60 °C for 4 - 6 h; the dosage ratio of diethylenetriaminepropyltrimethoxysilane, absolute ethanol, glycidyl and triethylamine is 100 - 110 g:30 - 34 g:200 - 230 mL:1.0 - 1.2 g.

9. A high-strength UV ink according to claim 7, characterized in that: In step 2, the constant - temperature stirring is carried out at 55 - 60 °C for 4 - 6 h; the dosage ratio of the intermediate, glacial acetic acid, absolute ethanol and benzaldehyde derivative is 12 - 15 g:0.02 - 0.03 g:22 - 25 mL:3.4 - 3.8 g.

10. A method for preparing a high-strength UV ink according to any one of claims 1 to 9, characterized in that, The preparation method comprises the following steps: stirring and mixing a reaction monomer, a photoinitiator, a pigment, an antifoaming agent and a solvent, and adding a modified acrylate emulsion and continuing to stir to obtain the product.

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