High-color-rendering water-based ink composition and preparation method thereof

Abstract

The invention relates to a high-color-rendering water-based ink composition and a preparation method thereof. The high-color-rendering water-based ink composition comprises the following components in parts by mass: 30-40 parts of acrylic resin, 8-10 parts of acrylate, 5-20 parts of acrylate, 10-20 parts of pigment, 2-8 parts of modified silicon dioxide, 1-4 parts of a pH regulator, 0.2-0.5 part of salt, 0.1-2 parts of an initiator, 0.2-6 parts of an auxiliary agent and 10-30 parts of a solvent. The modified silicon dioxide is amino acid modified silicon dioxide. The styrene-acrylic emulsion, various acrylic monomers, modified silicon dioxide, zinc salt and ammonia water are compounded, so that the compatibility among different components is improved, the crosslinking degree among substances is improved, the color development effect, stability and strength of the ink are enhanced, the defects in the prior art are overcome, and the ink is suitable for industrial production. The method is of great significance to promotion of industry development and meeting of market diversification requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of inks, in particular to a high-color water-based ink composition and a preparation method thereof. Background Art

[0002] As the printing industry develops towards a green and sustainable future, water-based inks are becoming increasingly popular due to their environmentally friendly properties and are widely used in areas such as packaging paper printing. Market demands for printed product quality are also constantly increasing, and the performance of water-based inks has become a key factor influencing printing results.

[0003] Key components of water-based inks, such as the common styrene-acrylic emulsion, while offering advantages such as excellent adhesion, water resistance, and weather resistance, suffer from relatively high transparency after film formation. This results in weak hiding power and poor color rendering in ink applications. This is particularly true on paper types such as brown kraft, which require high hiding power, making it difficult to meet practical requirements. Traditionally, high-color pigments have been added to enhance ink color rendering. However, these pigments often have fine primary particle sizes and are expensive, significantly increasing the production cost of water-based inks and hindering cost control and large-scale application.

[0004] Existing water-based ink products also suffer from insufficient compatibility between their components. Due to differences in molecular structure, pigments, resins, fillers, and additives are prone to uneven dispersion, stratification, or agglomeration, disrupting uniform color presentation and directly reducing color saturation. Furthermore, poor cross-linking during the ink curing process results in a loose film structure and irregular light scattering within the film. This not only reduces color stability but also significantly compromises color expressiveness, further exacerbating the degradation of color rendering.

[0005] In addition, the loose film structure will also reduce the fixing strength of the particles in the film. As the use time goes by, the pigments are prone to migration or fall off, further aggravating the deterioration of the color rendering effect. The film is also prone to defects such as aging, blistering, and cracking, shortening the effective service life of the printed product.

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

[0007] Based on this, the present invention provides a highly colorable water-based ink composition and its preparation method. This invention utilizes a styrene-acrylic emulsion, multiple acrylic acid monomers, modified silica, zinc salt, and ammonia solution to improve the compatibility between the various components and enhance the degree of cross-linking between the substances, thereby enhancing the color development, stability, and strength of the ink. This addresses the shortcomings of existing technologies 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 highly colorable 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 regulator is aqueous ammonia.

[0013] Furthermore, the auxiliary agent includes an emulsifier, a dispersant and a defoaming agent.

[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 highly color-developing water-based ink composition, wherein the method for preparing the highly color-developing water-based ink composition comprises the following steps:

[0018] S1, adding acrylic resin to a solvent, then adding salt and a pH adjuster, stirring and heating to obtain an intermediate product 1;

[0019] S2, adding acrylate, acrylate, initiator and auxiliary agent to the intermediate product 1, heating and reacting to obtain intermediate product 2;

[0020] S3, hydroxylating the silica, mixing it with amino acid, and heating it for reaction to obtain modified silica;

[0021] S4. Add the modified silica and other ingredients to the intermediate product 2, and stir evenly to obtain a high color-developing 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] Furthermore, in step S3, the mass ratio of silicon dioxide to amino acid 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 development water-based ink composition provided by the present invention uses styrene acrylic emulsion as a base component, and then adds ammonia water and zinc chloride, which react to form a zinc ammonia complex [Zn(NH3)4] 2+ , stably existing in the resin system in the form of ammonia complex ions, and then adding acrylate and acrylate to carry out polymerization reaction to form acrylate-acrylate polymer; at the same time, the present invention also uses hydroxylated silica with high activity to react with 3-hydroxy-L-tyrosine, and the modification is achieved by the reaction of hydroxyl and carboxyl groups on the surface of inorganic particles. As a result, after the ink composition of the present invention is heated and cured to form a film, volatile alkaline components such as ammonia gradually escape, the pH value of the system decreases, the metal complex dissociates, and the Zn with coordination activity is released. 2+ , it undergoes a chelation reaction with the amino and phenolic hydroxyl groups introduced in the modified silica, and the carboxylate groups in the acrylate-acrylate polymer to form cross-links, obtaining a more stable three-dimensional cross-linked structure, which promotes the improvement of ink stability, solvent resistance, strength and other properties. Thanks to the stable cross-linked structure, the migration and agglomeration of components such as pigments are also inhibited, which is conducive to achieving better color rendering effects.

[0028] In addition, the organically modified silica of the present invention has more polar groups, which, on the one hand, enhances the compatibility with components such as the matrix resin, polyacrylate, and pigment, and is beneficial to its own dispersion; on the other hand, it can also form a synergistic effect with components such as dispersants and emulsifiers to further improve the uniformity of the composition; in addition, a large number of active groups in different components can also be cross-linked through chemical bonds, hydrogen bonds, etc., which promotes the improvement of the comprehensive performance of the ink. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0030] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0031] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0032] The styrene acrylic emulsion in the embodiment of the present invention is Budford RS-300S.

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

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

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

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

[0037] The “parts” in the embodiments of the present invention refer to parts by mass.

[0038] Example 1

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

[0040]

[0041] The method for preparing the highly color-developing water-based ink composition comprises the following steps:

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

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

[0044] S3, immersing silicon dioxide (particle size 50-100 nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30 wt %) in a volume ratio of 7:3, and reacting at 80° C. for 1 h to obtain hydroxylated silicon dioxide;

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

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

[0047] Example 2

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

[0049]

[0050]

[0051] The method for preparing the highly color-developing water-based ink composition comprises the following steps:

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

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

[0054] S3, immersing silicon dioxide (particle size 50-100 nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30 wt %) in a volume ratio of 7:3, and reacting at 80° C. for 1 h to obtain hydroxylated silicon dioxide;

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

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

[0057] Example 3

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

[0059]

[0060]

[0061] The method for preparing the highly color-developing water-based ink composition comprises the following steps:

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

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

[0064] S3, immersing silicon dioxide (particle size 50-100 nm) in a mixed solution of concentrated sulfuric acid and hydrogen peroxide (30 wt %) in a volume ratio of 7:3, and reacting at 80° C. for 1 h to obtain hydroxylated silicon dioxide;

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

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

[0067] Comparative Example 1

[0068] A highly color-developing water-based ink composition. The difference between this comparative example and Example 1 is that zinc chloride is replaced by water, and the other ingredients and preparation method are the same as those in Example 1.

[0069] Comparative Example 2

[0070] A highly color-developing water-based ink composition. The difference between this comparative example and Example 1 is that in step S3, 3-hydroxy-L-tyrosine is replaced by lauric acid. Other components and preparation methods are the same as those 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 respectively coated on the surface of a PET substrate and dried at 60° C. for 5 h to obtain samples.

[0073] Adhesion: tested by the 100-grid method.

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

[0075] Water resistance: Hang a paper towel moistened with clean water vertically until water stops dripping, then wipe the sample back and forth 10 times with the wet paper towel. Observe the paper towel, and it is qualified if there is no discoloration.

[0076] Abrasion resistance: Use ink abrasion resistance tester for testing, rub 100 times with 4 pounds of pressure, and it is qualified if there is no fading.

[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 Tinting strength 98.8％ 98.9％ 99.1％ 98.4％ 98.1％ Water resistance qualified qualified qualified Unqualified qualified wear resistance qualified qualified qualified Unqualified Unqualified

[0080] As can be seen from Table 1, the highly colorable water-based ink compositions prepared in Examples 1-3 of the present invention exhibit excellent coloring and color development, good adhesion, and excellent water resistance. They exhibit no fading after wiping with a wet tissue, and possess high strength, with no pigment shedding or migration after friction. However, in Comparative Example 1, where zinc chloride is replaced with water, the composition fails to form a robust structure with multiple components fully cross-linked. This results in reduced adhesion and tinting power, insufficient strength, poor abrasion resistance, and a significantly increased hydrophilicity, leading to fading after wiping with a wet tissue. In Comparative Example 2, due to the modification of silica with lauric acid, the bonding between the components is significantly weakened, and various performance properties also decline to varying degrees.

[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 embodied 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 illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0082] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A highly colorable water-based ink composition, characterized in that: The highly colorable water-based ink composition comprises the following components in parts by mass: The modified silica is amino acid modified silica.

2. The highly color-developing water-based ink composition according to claim 1, characterized in that: The acrylic resin is styrene acrylic emulsion.

3. The highly color-developing water-based ink composition according to claim 1, characterized in that: The pH regulator is aqueous ammonia.

4. The highly color-developing water-based ink composition according to claim 1, characterized in that: The auxiliary agents include emulsifiers, dispersants and defoamers.

5. The highly color-developing water-based ink composition according to claim 1, characterized in that: The salt is zinc chloride.

6. The method for preparing the highly color-developing water-based ink composition according to any one of claims 1 to 5, characterized in that: The preparation method of the highly colorable water-based ink composition comprises the following steps: S1, adding acrylic resin to a solvent, then adding salt and a pH adjuster, stirring and heating to obtain an intermediate product 1; S2, adding acrylate, acrylate, initiator and auxiliary agent to the intermediate product 1, heating and reacting to obtain intermediate product 2; S3, hydroxylating the silica, mixing it with amino acid, and heating it for reaction to obtain modified silica; S4. Add the modified silica and other ingredients to the intermediate product 2, and stir evenly to obtain a high color-developing water-based ink composition.

7. The method for preparing a highly color-developing water-based ink composition according to claim 6, wherein: In step S1, the temperature of the heating reaction is 30-60°C.

8. The method for preparing a highly color-developing water-based ink composition according to claim 6, wherein: In step S2, the temperature of the heating reaction is 50-90°C.

9. The method for preparing a highly color-developing water-based ink composition according to claim 6, wherein: In step S3, the mass ratio of silicon dioxide to amino acid is (0.5-2):

1.

10. The method for preparing a highly color-developing water-based ink composition according to claim 6, wherein: In step S3, the temperature of the heating reaction is 60-90°C.

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