A high color rendering water-based ink composition and its preparation method

Abstract

This invention relates to a high-color-rendering water-based ink composition and its preparation method, comprising the following components in parts by weight: 30-40 parts acrylic resin, 8-10 parts acrylate, 5-20 parts acrylate, 10-20 parts pigment, 2-8 parts modified silica, 1-4 parts pH adjuster, 0.2-0.5 parts salt, 0.1-2 parts initiator, 0.2-6 parts additives, and 10-30 parts solvent; wherein the modified silica is amino acid-modified silica. This invention uses a styrene-acrylic emulsion, various acrylic monomers, modified silica, zinc salt, and ammonia water in a compound, which not only improves the compatibility between different components but also enhances the degree of cross-linking between substances, thereby strengthening the color rendering effect, stability, and strength of the ink. It overcomes the shortcomings of existing technologies and is of great significance for promoting industry development and meeting diversified market demands.

Description

Technical Field

[0001] This invention relates to the field of ink technology, and in particular to a high-color-rendering water-based ink composition and its preparation method. Background Technology

[0002] As the printing industry moves towards green and sustainable development, water-based inks, due to their environmentally friendly properties, are gaining increasing popularity and are widely used in packaging paper printing and other fields. Market demands for print quality are also constantly rising, making the performance of water-based inks a key factor influencing print quality.

[0003] While key components of water-based inks, such as common styrene-acrylic emulsions, offer advantages like excellent adhesion, water resistance, and weather resistance, they also suffer from relatively high transparency after film formation. This results in poor opacity and color development in ink applications, particularly on paper types like brown kraft paper where high opacity is crucial, making it difficult to meet practical needs. Traditional methods to improve ink color development often involve adding high-color-developing pigments. However, these pigments typically have finer primary particle sizes and are expensive, significantly increasing the production cost of water-based inks and hindering cost control and large-scale application in the industry.

[0004] In existing water-based ink products, insufficient compatibility among the components remains a problem. Pigments, resins, fillers, and additives, due to differences in molecular structure, are prone to uneven dispersion, layering, or aggregation, disrupting uniform color presentation and directly weakening color saturation. Simultaneously, poor cross-linking during ink curing results in a loose film structure, causing irregular light scattering within the film layer. This not only reduces color stability but also significantly diminishes color performance, further exacerbating the deterioration of color rendering.

[0005] In addition, a loose film structure reduces the fixation strength of particles in the film. As the usage time increases, pigments are prone to migration or shedding, further exacerbating the deterioration of color development. The film is also prone to defects such as aging, blistering, and cracking, shortening the effective service life of printed materials.

[0006] Therefore, how to develop a new type of high-color-rendering ink product that can overcome the various defects of existing water-based inks and has excellent comprehensive performance has become a key issue that the printing industry urgently needs to solve. Summary of the Invention

[0007] Based on this, the present invention provides a high-color-rendering water-based ink composition and its preparation method. The present invention uses styrene-acrylic emulsion, various acrylic monomers, modified silica, zinc salt, and ammonia water in a compound, which not only improves the compatibility between different components but also enhances the degree of cross-linking between substances, thereby strengthening the color rendering effect, stability, and strength of the ink. This solves the defects existing in the prior art and is of great significance for promoting industry development and meeting diversified market demands.

[0008] One object of the present invention is to provide a high color rendering water-based ink composition, said high color rendering water-based ink composition comprising the following components in parts by weight:

[0009]

[0010] The modified silica is amino acid-modified silica.

[0011] Furthermore, the acrylic resin is a styrene-acrylic emulsion.

[0012] Furthermore, the pH adjuster is ammonia.

[0013] Furthermore, the additives include emulsifiers, dispersants, and defoamers.

[0014] Furthermore, the salt is zinc chloride.

[0015] Furthermore, the acrylate includes alkyl acrylate and hydroxyalkyl acrylate.

[0016] Furthermore, the amino acid is 3-hydroxy-L-tyrosine.

[0017] Another object of the present invention is to provide a method for preparing the above-mentioned high color rendering water-based ink composition, wherein the method for preparing the high color rendering water-based ink composition includes the following steps:

[0018] S1. Add acrylic resin to a solvent, then add salt and pH adjuster, stir and heat to obtain intermediate product 1;

[0019] S2. Add acrylate, acrylate, initiator and auxiliaries to intermediate product 1, and heat to react to obtain intermediate product 2;

[0020] S3. After hydroxylating silica, it is mixed with amino acids and heated to react, thus obtaining modified silica.

[0021] S4. Add the modified silica and other components to intermediate product 2, stir evenly, and obtain a high-color-rendering water-based ink composition.

[0022] Furthermore, in step S1, the temperature of the heating reaction is 30-60°C.

[0023] Furthermore, in step S2, the temperature of the heating reaction is 50-90°C.

[0024] Further, in step S3, the mass ratio of silicon dioxide to amino acids is (0.5-2):1.

[0025] Furthermore, in step S3, the temperature of the heating reaction is 60-90°C.

[0026] The present invention has the following beneficial effects:

[0027] The high-color-rendering water-based ink composition provided by this invention uses styrene-acrylic emulsion as the base component, then adds ammonia and zinc chloride, which react to form a zinc-ammonia complex [Zn(NH3)4]. 2+ The ammonia complex exists stably in the resin system, and then acrylate and acrylate are added for polymerization to form an acrylate-acrylate polymer. Simultaneously, this invention also uses highly reactive hydroxylated silica to react with 3-hydroxy-L-tyrosine, achieving modification through the reaction of hydroxyl and carboxyl groups on the surface of inorganic particles. Therefore, after the ink composition of this invention is heated and cured into a film, volatile alkaline components such as ammonia gradually escape, the pH value of the system decreases, the metal complex dissociates, and coordinate-active Zn is released. 2+ It undergoes a chelation reaction with the amino and phenolic hydroxyl groups introduced in the modified silica, as well as the carboxyl groups in the acrylate-acrylate polymer, to form a crosslink, resulting in a more stable three-dimensional crosslink structure. This promotes the improvement of ink stability, solvent resistance, strength, and other properties. Furthermore, thanks to the stable crosslink structure, the migration and aggregation of pigments and other components are also suppressed, which is conducive to achieving better color development.

[0028] In addition, the silica modified by organic modification in this invention has more polar groups, which on the one hand enhances its compatibility with matrix resins, polyacrylates, pigments and other components, and is beneficial to its own dispersion; on the other hand, it can also form a synergistic effect with dispersants, emulsifiers and other components, further improving the uniformity of the composition; in addition, a large number of active groups in different components can also crosslink through chemical bonds, hydrogen bonds and other forms, promoting the improvement of the overall performance of the ink. Detailed Implementation

[0029] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0030] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0031] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0032] The styrene-acrylic emulsion used in this embodiment of the invention is BADEFU RS-300S.

[0033] The pigment used in this embodiment of the invention is Pigment Yellow 12.

[0034] The ammonia concentration in this embodiment of the invention is 25%.

[0035] The initiator in this embodiment of the invention is ammonium persulfate.

[0036] The additives in this embodiment of the invention are dispersant BYK110, defoamer BYK-141 and emulsifier Tween 100 in a mass ratio of 1:1:2.

[0037] In the embodiments of this invention, "parts" refers to parts by mass.

[0038] Example 1

[0039] A high-color-rendering water-based ink composition, the high-color-rendering water-based ink composition comprising the following components in parts by weight:

[0040]

[0041] The preparation method of the high color rendering water-based ink composition includes the following steps:

[0042] S1. Add the styrene-acrylic emulsion to water according to the above mass proportions, then add zinc chloride and ammonia water, stir at 50°C for 30 min to obtain intermediate product 1;

[0043] S2. Sodium acrylate, butyl acrylate, hydroxyethyl methacrylate, initiator and auxiliaries are added to intermediate product 1, and the mixture is reacted at 80°C for 4 hours under nitrogen protection to obtain intermediate product 2.

[0044] S3. Immerse silica (particle size 50-100nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30wt%) with a volume ratio of 7:3, and react at 80℃ for 1h to obtain hydroxylated silica.

[0045] Using dimethyl sulfoxide as solvent, the hydroxylated silica was mixed with 3-hydroxy-L-tyrosine at a mass ratio of 1:1.5, and the mixture was ultrasonically reacted at 80°C for 10 h. The mixture was then filtered and dried to obtain modified silica.

[0046] S4. Add the modified silica and other components to intermediate product 2, stir evenly, and obtain a high-color-rendering water-based ink composition.

[0047] Example 2

[0048] A high-color-rendering water-based ink composition, the high-color-rendering water-based ink composition comprising the following components in parts by weight:

[0049]

[0050]

[0051] The preparation method of the high color rendering water-based ink composition includes the following steps:

[0052] S1. Add the styrene-acrylic emulsion to water according to the above mass proportions, then add zinc chloride and ammonia water, stir at 50°C for 30 min to obtain intermediate product 1;

[0053] S2. Sodium acrylate, butyl acrylate, hydroxyethyl methacrylate, initiator and auxiliaries are added to intermediate product 1, and the mixture is reacted at 80°C for 4 hours under nitrogen protection to obtain intermediate product 2.

[0054] S3. Immerse silica (particle size 50-100nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30wt%) with a volume ratio of 7:3, and react at 80℃ for 1h to obtain hydroxylated silica.

[0055] Using dimethyl sulfoxide as solvent, the hydroxylated silica was mixed with 3-hydroxy-L-tyrosine at a mass ratio of 1:1.5, and the mixture was ultrasonically reacted at 80°C for 10 h. The mixture was then filtered and dried to obtain modified silica.

[0056] S4. Add the modified silica and other components to intermediate product 2, stir evenly, and obtain a high-color-rendering water-based ink composition.

[0057] Example 3

[0058] A high-color-rendering water-based ink composition, the high-color-rendering water-based ink composition comprising the following components in parts by weight:

[0059]

[0060]

[0061] The preparation method of the high color rendering water-based ink composition includes the following steps:

[0062] S1. Add the styrene-acrylic emulsion to water according to the above mass proportions, then add zinc chloride and ammonia water, stir at 50°C for 30 min to obtain intermediate product 1;

[0063] S2. Sodium acrylate, butyl acrylate, hydroxyethyl methacrylate, initiator and auxiliaries are added to intermediate product 1, and the mixture is reacted at 80°C for 4 hours under nitrogen protection to obtain intermediate product 2.

[0064] S3. Immerse silica (particle size 50-100nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30wt%) with a volume ratio of 7:3, and react at 80℃ for 1h to obtain hydroxylated silica.

[0065] Using dimethyl sulfoxide as solvent, the hydroxylated silica was mixed with 3-hydroxy-L-tyrosine at a mass ratio of 1:1.5, and the mixture was ultrasonically reacted at 80°C for 10 h. The mixture was then filtered and dried to obtain modified silica.

[0066] S4. Add the modified silica and other components to intermediate product 2, stir evenly, and obtain a high-color-rendering water-based ink composition.

[0067] Comparative Example 1

[0068] A high-color-rendering water-based ink composition, the difference between this comparative example and Example 1 is that zinc chloride is replaced with water, while the other components and preparation methods are the same as in Example 1.

[0069] Comparative Example 2

[0070] A high-color-rendering water-based ink composition, the difference between this comparative example and Example 1 is that in step S3, 3-hydroxy-L-tyrosine is replaced with lauric acid, while the other components and preparation methods are the same as in Example 1.

[0071] Test case

[0072] The highly color-developing water-based ink compositions prepared in Examples 1-3 and Comparative Examples 1-2 were coated onto the surface of PET substrates and dried at 60°C for 5 hours to obtain samples.

[0073] Adhesion: Tested using the cross-cut adhesion test.

[0074] Tinting strength: Tested according to GB / T14624.2-2008.

[0075] Water resistance: Hang a paper towel that has been moistened with clean water vertically until the water stops dripping. Wipe the sample back and forth 10 times with the wet paper towel and observe the paper towel. If there is no color fading, it is considered qualified.

[0076] Abrasion resistance: Tested using an ink abrasion tester, with 100 cycles of 4-pound pressure; no color fading is considered acceptable.

[0077] The test results are shown in Table 1.

[0078] Table 1 Performance Test Results

[0079] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesion 3% shedding 3% shedding 2% shedding 5% shedding 4% shedding Coloring power 98.8％ 98.9％ 99.1％ 98.4％ 98.1％ Water resistance qualified qualified qualified Unqualified qualified abrasion resistance qualified qualified qualified Unqualified Unqualified

[0080] As shown in Table 1, the high-color-rendering water-based ink compositions prepared in Examples 1-3 of this invention exhibit good coloring and color-rendering effects, good adhesion, and excellent water resistance. No color fading was observed after wiping with a damp paper towel, and the composition also showed high strength, with no pigment detachment or migration after rubbing. In contrast, Comparative Example 1, where zinc chloride was replaced with water, failed to form a stable cross-linked structure among the various components. This resulted in reduced adhesion and coloring power, insufficient strength, poor abrasion resistance, and a significant increase in hydrophilicity, leading to color fading after wiping with a damp paper towel. Comparative Example 2, due to the modification of silica with lauric acid, significantly weakened the bonding effect between components, resulting in varying degrees of decline in multiple properties.

[0081] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0082] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high chroma water-based ink composition characterized in that, The high color rendering water-based ink composition comprises ingredients in mass parts as follows: acrylic resin 30-40 parts acrylate 5-20 parts pigment 10-20 parts modified silica 2-8 parts ammonia 1-4 parts zinc chloride 0.2-0.5 parts initiator 0.1-2 parts auxiliary 0.2-6 parts solvent 10-30 parts. The modified silica is amino acid modified silica. The preparation method of the high color rendering water-based ink composition comprises the following steps: S1, add acrylic resin to solvent, then add salt and pH adjuster, stir and heat to obtain intermediate product 1; S2, add acrylate, initiator and auxiliary to the intermediate product 1, and heat to react to obtain intermediate product 2; S3, after hydroxylation treatment of silica, mix with amino acid, heat to react to obtain modified silica; S4, add the modified silica and other ingredients to intermediate product 2, stir uniformly to obtain high color rendering water-based ink composition; The amino acid is 3-hydroxy-L-tyrosine. The acrylic resin is styrene-acrylic emulsion.

2. The high chroma water-based ink composition according to claim 1, characterized by, The auxiliary includes emulsifier, dispersant and defoaming agent.

3. The high chroma water-based ink composition according to claim 1, characterized by, In step S1, the temperature of the heating reaction is 30-60℃.

4. The high chroma water-based ink composition according to claim 1, characterized by, In step S2, the temperature of the heating reaction is 50-90℃.

5. The high chroma water-based ink composition according to claim 1, wherein In step S3, the mass ratio of silica to amino acid is (0.5-2):

1.

6. The high chroma water-based ink composition according to claim 1, wherein In step S3, the temperature of the heating reaction is 60-90℃.

7. The high chroma water-based ink composition according to claim 1, wherein ​

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