Water-based gravure aluminum foil printing ink and its preparation method

Abstract

The present invention provides an aqueous gravure aluminum foil printing ink, which comprises the following components in parts by weight: 40-45 parts of acrylic emulsion, 10-15 parts of aqueous polyurethane emulsion, 8-10 parts of colorant, 2-3 parts of bentonite, 2-3 parts of polydopamine, 2-3 parts of aqueous polyamide, 0.2-0.5 part of defoamer, 0.5-1 part of wetting agent; 2-3 parts of film-forming aid; 3-5 parts of cross-linking agent; 0.3-0.5 part of preservative; wherein, the polydopamine includes first polydopamine and second polydopamine; the colorant is modified by aqueous polyamide and first polydopamine in sequence, and at the same time, the mixture of acrylic emulsion and aqueous polyurethane emulsion is modified by second polydopamine, so as to enhance the interaction force with the resin substrate while the colorant particles are dispersed without aggregation. The aqueous ink of the present invention can improve the dispersibility of colorant particles and the interaction force with the resin substrate, and combine with bentonite to improve the suspension stability of the ink system.

Description

Technical Field

[0001] The present invention relates to the technical field of printing inks, and particularly to an aqueous gravure aluminum foil printing ink and a preparation method thereof. Background Art

[0002] Gravure printing is an important printing technology. Its characteristic is to transfer the ink onto the substrate by using a gravure plate (the printed part of the plate is lower than the blank part) to produce printed matter. During gravure printing, since the ink only exists in the pits, a relatively thick ink layer can be formed during printing, so that the printed matter has full and bright colors. Also, due to the full transfer of the ink and the thickness of the ink layer, the colors of gravure printed products are bright and have high saturation. In addition, gravure printing also has the advantages of stable printing quality and high speed. Therefore, gravure printing is widely used in the fields of printing and packaging and graphic publishing, and occupies an important position in the printing industry.

[0003] Aqueous ink is an environment-friendly printing ink, which is characterized by using water as the main diluent instead of traditional organic solvents. It is particularly suitable for aluminum foil packaging printing products with strict hygiene requirements such as cigarettes, wines, foods, beverages, medicines, and children's toys. In particular, aqueous inks containing large-particle pigments can provide good adhesion and color saturation, and can ensure excellent visual effects and safety when the printed matter is packaged.

[0004] However, large-particle pigments can cause the ink to quickly precipitate after being placed. During the gravure aluminum foil printing process, the aqueous ink needs to maintain stability, and precipitation and stratification phenomena should be avoided to ensure printing quality. At present, in the prior art, anti-precipitants are mostly added to the ink system to prevent the precipitation of the ink, but the effect is not ideal for inks containing large-particle pigments. It is also possible to achieve anti-precipitation by increasing the viscosity of the ink. However, for inks containing large-particle pigments, the viscosity needs to be adjusted to a relatively high range to effectively prevent precipitation, and too high viscosity will affect the transfer performance, drying performance, etc. of the ink in aluminum foil printing, thus affecting the printing quality.

[0005] Therefore, in gravure aluminum foil printing, for aqueous inks containing large-particle pigments, it is urgent to solve the problem of how to effectively prevent precipitation without affecting printing quality. Summary of the Invention

[0006] The purpose of the present invention is to provide an aqueous gravure aluminum foil printing ink and a preparation method thereof for the problem of poor suspension of existing aqueous inks containing large-particle pigments. By sequentially modifying the colorant with aqueous polyamide and polydopamine, and at the same time modifying the resin substrate with polydopamine, the dispersibility of the colorant particles and the interaction force with the resin substrate are improved, and bentonite is combined to improve the suspension stability of the ink system.

[0007] According to the first aspect of the object of the present invention, there is provided an aqueous gravure aluminum foil printing ink, comprising the following components in parts by weight: 40-45 parts of acrylic emulsion, 10-15 parts of aqueous polyurethane emulsion, 8-10 parts of colorant, 2-3 parts of bentonite, 2-3 parts of polydopamine, 2-3 parts of aqueous polyamide, 0.2-0.5 parts of defoaming agent, 0.5-1 part of wetting agent; 2-3 parts of film-forming aid; 3-5 parts of crosslinking agent; 0.3-0.5 part of preservative;

[0008] Among them, the polydopamine includes first polydopamine and second polydopamine;

[0009] The colorant is modified with aqueous polyamide and first polydopamine in sequence, and at the same time, the mixture of acrylic emulsion and aqueous polyurethane emulsion is modified with second polydopamine, so as to disperse the colorant particles without aggregation and enhance the interaction force with the resin substrate.

[0010] Further, the mass ratio of the first polydopamine to the aqueous polyamide is 1:(2-3).

[0011] Further, the colorant is an inorganic pigment and / or an organic pigment.

[0012] Further, the particle size of the colorant is 20-50 μm.

[0013] Further, the defoaming agent is an organosilicon defoaming agent.

[0014] Further, the wetting agent is a fluorine-containing wetting agent.

[0015] Further, the film-forming aid is propylene glycol methyl ether acetate.

[0016] Further, the crosslinking agent is PM-YL100.

[0017] According to the second aspect of the object of the present invention, there is provided a preparation method of an aqueous gravure aluminum foil printing ink, comprising the following steps:

[0018] S1: Weigh the raw materials according to parts by weight, mix the aqueous polyamide, colorant and deionized water evenly, then add the first polydopamine, and continue to mix evenly to obtain a first mixed solution;

[0019] Mix the acrylic emulsion and the aqueous polyurethane emulsion with the second polydopamine to obtain a second mixed solution;

[0020] S2: Mix the first mixed solution, the second mixed solution, and the bentonite and wetting agent, and stir evenly to obtain a third mixed solution;

[0021] S3: Ball mill the third mixed solution to a fineness of ≤20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 200 - 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a cross-linking agent, and a preservative, and continue to stir until uniform to obtain a fourth mixed solution;

[0022] S4: Use deionized water to adjust the solid content of the fourth mixed solution to a range suitable for gravure printing to obtain a water-based gravure aluminum foil printing ink.

[0023] Further, the mass ratio of the first polydopamine to the water-based polyamide is 1:(2 - 3).

[0024] Compared with the prior art, the remarkable beneficial effects of the present invention are as follows:

[0025] For the water-based gravure aluminum foil printing ink of the present invention, the colorant is first modified with a water-based polyamide. On the one hand, the polyamide contains a large number of polar groups, and these groups have strong hydrophilicity, which can adsorb water molecules to form hydrogen bonds, changing the ionic strength and molecular structure of water; on the other hand, the hydroxyl and amine groups in the polyamide molecule can form chemical bonds with the surface of the colorant, reducing the attraction between colorant particles, increasing the chargeability of colorant particles, and thus reducing the binding force between colorants;

[0026] On this basis, the colorant is further modified with polydopamine, and the ratio of polydopamine to polyamide is controlled to ensure that polydopamine does not affect the action of polyamide. At the same time, the resin substrate is modified with polydopamine. In this way, when the colorant and the resin substrate are mixed, the colorant particles and the resin substrate enhance the interaction between the two through hydrogen bonds and / π-π stacking. Combined with bentonite, large particle colorants are evenly dispersed in the system, improving the suspension stability of the ink system.

[0027] For the water-based gravure aluminum foil printing ink of the present invention, the water-based polyamide in the system also improves the wetting and color development of the colorant, as well as the wettability and adhesion of the ink; at the same time, the polydopamine in the system further improves the ink adhesion, so it is more suitable for gravure aluminum foil printing with high color saturation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a process flow chart of the preparation of the water-based gravure aluminum foil printing ink of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] In order to better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0030] Aspects of the present invention are described herein with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those concepts and implementations described in more detail below, can be implemented in any of a number of ways.

[0031] In an exemplary embodiment of the present invention, an aqueous gravure aluminum foil printing ink is provided, which comprises the following components in parts by weight: 40 - 45 parts of acrylic emulsion, 10 - 15 parts of aqueous polyurethane emulsion, 8 - 10 parts of colorant, 2 - 3 parts of bentonite, 2 - 3 parts of polydopamine, 2 - 3 parts of aqueous polyamide, 0.2 - 0.5 part of defoamer, 0.5 - 1 part of wetting agent; 2 - 3 parts of film-forming aid; 3 - 5 parts of cross-linking agent; 0.3 - 0.5 part of preservative;

[0032] Wherein, the polydopamine includes a first polydopamine and a second polydopamine;

[0033] The colorant is modified successively with aqueous polyamide and the first polydopamine. By the modification of polyamide, the binding force between colorants is reduced. At the same time, the second polydopamine is used to modify the mixture of acrylic emulsion and aqueous polyurethane emulsion (both are simply referred to as resin substrates). On the basis of the interaction force between colorant particles, the interaction force between the colorant particles and the resin substrates is increased.

[0034] It can be understood that the ink system further includes deionized water, which is used to dissolve the components that need to be dissolved during the preparation process and for subsequent solid content adjustment.

[0035] As a preferred embodiment, the mass ratio of the first polydopamine to the aqueous polyamide is 1:(2 - 3). By controlling the ratio of polydopamine to polyamide, it is ensured that the polydopamine does not affect the interaction force of the polyamide.

[0036] As a preferred embodiment, the sum of the weight parts of the first polydopamine and the second polydopamine is 2 - 3 parts.

[0037] As a preferred embodiment, the colorant is an inorganic pigment and / or an organic pigment. It can be understood that the types of inorganic pigments and organic pigments are all common types in the art and will not be elaborated herein.

[0038] As a preferred embodiment, the particle size of the colorant is 20 - 50 μm.

[0039] As a preferred embodiment, the defoamer is an organosilicon defoamer, for example, at least one of fluorosiloxane, ethylene glycol siloxane, ethylene glycol siloxane or polydimethylsiloxane, to reduce the generation of ink bubbles.

[0040] As a preferred embodiment, the wetting agent is a fluorine-containing wetting agent, for example, fluorocarbonate FCS-004, which improves the wettability and adhesion of the ink to the aluminum foil surface.

[0041] As a preferred embodiment, the film-forming auxiliary is propylene glycol methyl ether acetate, which helps to form a uniform and dense ink film layer.

[0042] As a preferred embodiment, the cross-linking agent is PM-YL100, which provides excellent chemical resistance and mechanical properties.

[0043] It can be understood that the addition of the preservative is to ensure the stability of the ink during storage and use. Generally, a spectral preservative such as LFY-141 is used.

[0044] Combined Figure 1 As shown, in another exemplary embodiment of the present invention, a method for preparing an aqueous gravure aluminum foil printing ink is further provided, including the following steps:

[0045] S1: Weigh the raw materials by weight. After mixing the aqueous polyamide, the colorant and deionized water evenly, add the first polydopamine, and continue to mix evenly to obtain a first mixed solution;

[0046] Mix the acrylic emulsion and the aqueous polyurethane emulsion with the second polydopamine to obtain a second mixed solution;

[0047] S2: Mix the first mixed solution, the second mixed solution, and bentonite and the wetting agent, and stir evenly to obtain a third mixed solution;

[0048] S3: Ball-mill the third mixed solution until the fineness is ≤20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 200-300 rpm, and sequentially add the film-forming auxiliary, the defoaming agent, the cross-linking agent and the preservative, and continue to stir until uniform to obtain a fourth mixed solution;

[0049] S4: Use deionized water to adjust the solid content of the fourth mixed solution to a range suitable for gravure printing to obtain an aqueous gravure aluminum foil printing ink.

[0050] As a preferred embodiment, the mass ratio of the first polydopamine to the aqueous polyamide is 1:(2-3).

[0051] As a preferred embodiment, when the viscosity and the solid content cannot meet the requirements simultaneously during the adjustment process, the viscosity can be adjusted by adjusting the pH value.

[0052] As a preferred embodiment, the solid content is 30-35%.

[0053] It can be understood that the deionized water used in the preparation process can be added as needed on the basis of not affecting the adjustment of the final solid content.

[0054] For better understanding, the present invention will be further described below in conjunction with several specific examples. However, the preparation process is not limited thereto, and the content of the present invention is not limited thereto.

[0055] Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0056] The defoamer used in the following examples and comparative examples is fluorosilicone, the wetting agent is FCS-004, the film-forming auxiliary is propylene glycol methyl ether acetate, the cross-linking agent is M-YL100, the preservative is LFY-141, and the particle size of the colorant is 20 - 50 μm.

[0057] Example 1

[0058] 40 parts of acrylic emulsion, 10 parts of aqueous polyurethane emulsion, 8 parts of yellow colorant, 2 parts of bentonite, 2 parts of polydopamine, 2 parts of aqueous polyamide, 0.2 part of defoamer, 0.5 part of wetting agent, 2 parts of film-forming auxiliary, 3 parts of cross-linking agent, 0.3 part of preservative.

[0059] S1: Weigh the raw materials according to the parts by weight. Mix the aqueous polyamide, yellow colorant and deionized water evenly at a speed of 300 rpm, then add a part of polydopamine and continue to mix evenly at a speed of 300 rpm to obtain the first mixed solution. At this time, the mass ratio of aqueous polyamide to polydopamine is 2:1.

[0060] Mix the acrylic emulsion and aqueous polyurethane emulsion with the remaining polydopamine to obtain the second mixed solution.

[0061] S2: Mix the first mixed solution, the second mixed solution, as well as bentonite and wetting agent, stir at a speed of 300 rpm for 5 min and then stir at a speed of 600 rpm for 20 min to obtain the third mixed solution.

[0062] S3: Grind the third mixed solution to a fineness of ≤20 μm, then transfer it back to the stirrer, stir evenly at a speed of 300 rpm, and sequentially add the film-forming auxiliary, defoamer, cross-linking agent and preservative, and continue to stir at a speed of 300 rpm until evenly mixed to obtain the fourth mixed solution.

[0063] S4: Use deionized water to adjust the solid content of the fourth mixed solution to 30 - 35% to obtain the aqueous gravure aluminum foil printing ink.

[0064] Example 2

[0065] 45 parts of acrylic emulsion, 15 parts of aqueous polyurethane emulsion, 10 parts of red pigment, 3 parts of bentonite, 3 parts of polydopamine, 3 parts of aqueous polyamide, 0.5 part of defoamer, 1 part of wetting agent, 3 parts of film-forming aid, 5 parts of cross-linking agent, 0.5 part of preservative.

[0066] S1: Weigh the raw materials by weight parts. Mix the aqueous polyamide, red pigment and deionized water evenly at a rotation speed of 300 rpm, then add a part of polydopamine and continue to mix evenly at a rotation speed of 300 rpm to obtain the first mixed solution. At this time, the mass ratio of aqueous polyamide to polydopamine is 3:1.

[0067] Mix the acrylic emulsion and the aqueous polyurethane emulsion with the remaining polydopamine to obtain the second mixed solution.

[0068] S2: Mix the first mixed solution, the second mixed solution, bentonite and wetting agent, stir at a rotation speed of 300 rpm for 5 min and then stir at a rotation speed of 600 rpm for 20 min to obtain the third mixed solution.

[0069] S3: Grind the third mixed solution to a fineness ≤ 20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 300 rpm, and sequentially add the film-forming aid, defoamer, cross-linking agent and preservative, and continue to stir at a rotation speed of 300 rpm until evenly mixed to obtain the fourth mixed solution.

[0070] S4: Use deionized water to adjust the solid content of the fourth mixed solution to 30 - 35% to obtain the water-based gravure aluminum foil printing ink.

[0071] Example 3

[0072] 45 parts of acrylic emulsion, 10 parts of aqueous polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of aqueous polyamide, 0.3 part of defoamer, 0.8 part of wetting agent; 2 parts of film-forming aid; 4 parts of cross-linking agent; 0.4 part of preservative.

[0073] S1: Weigh the raw materials by weight parts. Mix the aqueous polyamide, black pigment and deionized water evenly at a rotation speed of 300 rpm, then add a part of polydopamine and continue to mix evenly at a rotation speed of 300 rpm to obtain the first mixed solution. At this time, the mass ratio of aqueous polyamide to polydopamine is 2:1.

[0074] Mix the acrylic emulsion and the aqueous polyurethane emulsion with the remaining polydopamine to obtain the second mixed solution.

[0075] S2: Mix the first mixed solution, the second mixed solution, bentonite, and a wetting agent, stir at a speed of 300 rpm for 5 min, and then stir at a speed of 600 rpm for 20 min to obtain a third mixed solution.

[0076] S3: Grind the third mixed solution to a fineness of ≤20 μm, then transfer it back to the stirrer, stir evenly at a speed of 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a cross-linking agent, and a preservative, and continue to stir at a speed of 300 rpm until evenly mixed to obtain a fourth mixed solution.

[0077] S4: Use deionized water to adjust the solid content of the fourth mixed solution to 30 - 35% to obtain a water-based gravure aluminum foil printing ink.

[0078] Comparative Example 1

[0079] 45 parts of acrylic emulsion, 10 parts of waterborne polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of waterborne polyamide, 0.3 parts of antifoaming agent, 0.8 parts of wetting agent; 2 parts of film-forming aid; 4 parts of cross-linking agent; 0.4 parts of preservative.

[0080] S1: Weigh the raw materials by weight parts, mix the waterborne polyamide, black pigment, and deionized water evenly at a speed of 300 rpm to obtain a first mixed solution.

[0081] Mix the acrylic emulsion and the waterborne polyurethane emulsion with polydopamine to obtain a second mixed solution.

[0082] S2: Mix the first mixed solution, the second mixed solution, bentonite, and a wetting agent, stir at a speed of 300 rpm for 5 min, and then stir at a speed of 600 rpm for 20 min to obtain a third mixed solution.

[0083] S3: Grind the third mixed solution to a fineness of ≤20 μm, then transfer it back to the stirrer, stir evenly at a speed of 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a cross-linking agent, and a preservative, and continue to stir at a speed of 300 rpm until evenly mixed to obtain a fourth mixed solution.

[0084] S4: Use deionized water to adjust the solid content of the fourth mixed solution to 30 - 35% to obtain a water-based gravure aluminum foil printing ink.

[0085] Comparative Example 2

[0086] 45 parts of acrylic emulsion, 10 parts of waterborne polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of waterborne polyamide, 0.3 parts of antifoaming agent, 0.8 parts of wetting agent; 2 parts of film-forming aid; 4 parts of cross-linking agent; 0.4 parts of preservative.

[0087] S1: Weigh the raw materials by weight parts. After mixing 1 part of polydopamine, black pigment and deionized water evenly at a rotation speed of 300 rpm, a first mixed solution is obtained.

[0088] Mix the acrylic emulsion and the waterborne polyurethane emulsion with the remaining polydopamine to obtain a second mixed solution.

[0089] S2: Mix the first mixed solution, the second mixed solution, bentonite and wetting agent, stir at a rotation speed of 300 rpm for 5 min and then stir at a rotation speed of 600 rpm for 20 min to obtain a third mixed solution.

[0090] S3: Grind the third mixed solution to a fineness ≤ 20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a cross-linking agent and a preservative, and continue to stir at a rotation speed of 300 rpm until evenly mixed to obtain a fourth mixed solution.

[0091] S4: Use deionized water to adjust the solid content of the fourth mixed solution to 30 - 35% to obtain a water-based gravure aluminum foil printing ink.

[0092] Comparative Example 3

[0093] 45 parts of acrylic emulsion, 10 parts of waterborne polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of waterborne polyamide, 0.3 part of antifoaming agent, 0.8 part of wetting agent; 2 parts of film-forming aid; 4 parts of cross-linking agent; 0.4 part of preservative.

[0094] S1: Weigh the raw materials by weight parts. After mixing a part of polydopamine, black pigment and deionized water evenly at a rotation speed of 300 rpm, add waterborne polyamide and continue to mix evenly at a rotation speed of 300 rpm. At this time, the mass ratio of waterborne polyamide to polydopamine is 2:1 to obtain a first mixed solution.

[0095] Mix the acrylic emulsion and the waterborne polyurethane emulsion with the remaining polydopamine to obtain a second mixed solution.

[0096] S2: Mix the first mixed solution, the second mixed solution, bentonite and wetting agent, stir at a rotation speed of 300 rpm for 5 min and then stir at a rotation speed of 600 rpm for 20 min to obtain a third mixed solution.

[0097] S3: Grind the third mixed solution to a fineness ≤ 20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a cross-linking agent and a preservative, and continue to stir at a rotation speed of 300 rpm until evenly mixed to obtain a fourth mixed solution.

[0098] S4: Adjust the solid content of the fourth mixed solution to 30 - 35% using deionized water to obtain the water-based gravure aluminum foil printing ink.

[0099] Comparative Example 4

[0100] 45 parts of acrylic emulsion, 10 parts of waterborne polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of waterborne polyamide, 0.3 part of defoamer, 0.8 part of wetting agent; 2 parts of film-forming aid; 4 parts of crosslinking agent; 0.4 part of preservative.

[0101] S1: Weigh the raw materials by weight parts. Mix the waterborne polyamide, black pigment and deionized water evenly at a speed of 300 rpm, then add polydopamine and continue to mix evenly at a speed of 300 rpm to obtain the first mixed solution.

[0102] S2: Mix the first mixed solution, bentonite and wetting agent, stir at a speed of 300 rpm for 5 min and then stir at a speed of 600 rpm for 20 min to obtain the third mixed solution.

[0103] S3: Grind the third mixed solution to a fineness of ≤20 μm, then transfer it back to the stirrer, stir evenly at a speed of 300 rpm, and sequentially add the film-forming aid, defoamer, crosslinking agent and preservative, and continue to stir at a speed of 300 rpm until evenly mixed to obtain the fourth mixed solution.

[0104] S4: Adjust the solid content of the fourth mixed solution to 30 - 35% using deionized water to obtain the water-based gravure aluminum foil printing ink.

[0105] Comparative Example 5

[0106] 45 parts of acrylic emulsion, 10 parts of waterborne polyurethane emulsion, 10 parts of black pigment, 3 parts of bentonite, 3 parts of polydopamine, 2 parts of waterborne polyamide, 0.3 part of defoamer, 0.8 part of wetting agent; 2 parts of film-forming aid; 4 parts of crosslinking agent; 0.4 part of preservative.

[0107] S1: Weigh the raw materials by weight parts. Mix the waterborne polyamide, black pigment and deionized water evenly at a speed of 300 rpm, then add a part of polydopamine and continue to mix evenly at a speed of 300 rpm to obtain the first mixed solution. At this time, the mass ratio of waterborne polyamide to polydopamine is 2:1.

[0108] Mix the acrylic emulsion and waterborne polyurethane emulsion with the remaining polydopamine to obtain the second mixed solution.

[0109] S2: Mix the first mixed solution, the second mixed solution, and the wetting agent, stir at a speed of 300 rpm for 5 min and then stir at a speed of 600 rpm for 20 min to obtain a third mixed solution.

[0110] S3: Ball-mill the third mixed solution to a fineness of ≤ 20 μm, then transfer it back to the stirrer, stir evenly at a speed of 300 rpm, and sequentially add a film-forming aid, an antifoaming agent, a crosslinking agent, and a preservative, and continue to stir at a speed of 300 rpm until evenly mixed to obtain a fourth mixed solution.

[0111] S4: Adjust the solid content to 30 - 35% using deionized water to obtain a water-based gravure aluminum foil printing ink.

[0112] Performance Test

[0113] [[ID=1B]]Perform performance tests on the water-based inks prepared in Examples 1 - 3 and Comparative Examples 1 - 5. Among them, the viscosity is determined according to the inspection method for the viscosity of liquid inks GB / T13217.4 - 2008, the adhesion fastness is determined according to the inspection method for the adhesion fastness of liquid inks GB / T13217.7 - 2009, the tinting strength is evaluated according to the inspection method for the tinting strength of liquid inks GB / T13217.6 - 2008, and the initial dryness is tested according to the inspection method for the initial dryness of liquid inks GB / T13217.5 - 2008. The results are as follows

[0114]

[0115] It can be seen from the above results that the water-based gravure aluminum foil printing ink prepared by the present invention has excellent suspension stability, and at the same time has excellent printing properties such as transfer performance and drying performance, meets the printing requirements of water-based inks containing large particle pigments, and can also provide good adhesion and color saturation, ensuring excellent visual effects and safety during the packaging of printed products.

[0116] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to what is defined by the claims.

Claims

1. An aqueous gravure aluminum foil printing ink, characterized in that, It comprises components in the following parts by weight: 40 - 45 parts of acrylic emulsion, 10 - 15 parts of aqueous polyurethane emulsion, 8 - 10 parts of colorant, 2 - 3 parts of bentonite, 2 - 3 parts of polydopamine, 2 - 3 parts of aqueous polyamide, 0.2 - 0.5 part of defoamer, 0.5 - 1 part of wetting agent, 2 - 3 parts of film-forming aid, 3 - 5 parts of cross-linking agent, 0.3 - 0.5 part of preservative; Among them, the polydopamine includes first polydopamine and second polydopamine, and the mass ratio of the first polydopamine to the aqueous polyamide is 1:(2 - 3); The colorant is modified successively with aqueous polyamide and first polydopamine, and at the same time the mixture of acrylic emulsion and aqueous polyurethane emulsion is modified with second polydopamine, so that the colorant particles are dispersed without aggregation while enhancing the interaction with the resin substrate.

2. The water-based gravure aluminum foil printing ink according to claim 1, wherein The colorant is an inorganic pigment and / or an organic pigment.

3. The water-based gravure aluminum foil printing ink according to claim 1, characterized in that, The particle size of the colorant is 20 - 50 μm.

4. The water-based gravure aluminum foil printing ink according to claim 1, wherein, The defoamer is a silicone defoamer.

5. The water-based gravure aluminum foil printing ink according to claim 1, characterized in that, The wetting agent is a fluorine-containing wetting agent.

6. The water-based gravure aluminum foil printing ink according to claim 1, characterized in that, The film-forming aid is propylene glycol methyl ether acetate.

7. The water-based gravure aluminum foil printing ink according to claim 1, characterized in that, The cross-linking agent is PM-YL100.

8. A preparation method of the water-based gravure aluminum foil printing ink as described in claim 1, characterized in that, It includes the following steps: S1: Weigh the raw materials according to the parts by weight. Mix the aqueous polyamide, colorant and deionized water evenly, then add the first polydopamine and continue to mix evenly to obtain a first mixed solution; Mix the acrylic emulsion and aqueous polyurethane emulsion with the second polydopamine to obtain a second mixed solution; S2: Mix the first mixed solution, the second mixed solution, and the bentonite and wetting agent, and stir evenly to obtain a third mixed solution; S3: Ball-mill the third mixed solution until the fineness ≤ 20 μm, then transfer it back to the stirrer, stir evenly at a rotation speed of 200 - 300 rpm, and successively add the film-forming aid, defoamer, cross-linking agent and preservative, and continue to stir until uniform to obtain a fourth mixed solution; S4: Use deionized water to adjust the solid content of the fourth mixed solution to the range suitable for gravure printing to obtain an aqueous gravure aluminum foil printing ink.

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