Water-based ink composition

Abstract

The invention provides a water-based ink composition which comprises the following components in percentage by weight: 48.0-70.0% of a solvent, 35.0-50.0% of a coloring agent, 0.3-1.5% of a surface active agent and 0.2-1.0% of a dispersing agent, and the sum of the weight percentages of the components is 100%. Wherein the surfactant is ethoxylated alkynediol, and the dispersing agent is nonionic polyacrylamide and a derivative of the nonionic polyacrylamide. Compared with the prior art, the ethoxylated alkynediol, the nonionic polyacrylamide and the derivative thereof are added into the water-based ink composition, so that the cover opening time of ink can be greatly prolonged, and the jet printing efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of ink technology, and in particular to a water-based ink composition. Background Technology

[0002] Inkjet printing technology, based on existing digital technology, ejects ink droplets onto a substrate in a specific sequence, creating graphics by directly depositing a large number of tiny droplets onto the substrate. Due to its low cost, high quality, and wide applicability to various media, inkjet printing is gradually becoming the mainstream digital graphic printing method.

[0003] Common types of inkjet printing equipment include: continuous inkjet printers (CIJ type), drop-on-demand inkjet printers (DOD type), and piezoelectric inkjet printers (PIJ type). Among these, piezoelectric inkjet printers (PIJ type) use the deformation of piezoelectric crystals to propel ink out, achieving high-precision printing. Piezoelectric inkjet technology offers stronger control over ink droplets, resulting in more regular droplet shapes, more accurate positioning, and improved printing resolution, making it easier to achieve high-precision printing.

[0004] Depending on the application scenario, PIJ inkjet printer inks are generally divided into two types: solvent-based and water-based. Solvent-based inks typically use alcohols or ketones as the main solvent, while water-based inks use water as the main solvent. Currently, the shorter cap opening time of water-based inks significantly impacts printing efficiency. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a water-based ink composition.

[0006] The water-based ink composition of the present invention comprises, by weight percentage, the following components:

[0007]

[0008] The total weight percentage of all components is 100%; wherein the surfactant is ethoxylated acetylenic diol and the dispersant is nonionic polyacrylamide and its derivatives.

[0009] Compared with existing technologies, the present invention adds ethoxylated acetylene glycol and nonionic polyacrylamide and its derivatives to the water-based ink composition, which can greatly extend the ink cap opening time and improve printing efficiency.

[0010] In one embodiment, the water-based ink composition further includes a bactericide, wherein the bactericide is present in a weight percentage of 0.1-0.2%.

[0011] In one embodiment, the bactericide is MBS bactericide.

[0012] In one embodiment, the water-based ink composition further includes a pH adjuster, wherein the pH adjuster is present in a mass percentage of 0.1-5.0%.

[0013] In one embodiment, the pH adjuster is ethanolamine.

[0014] In one embodiment, the water-based ink composition further includes a humectant, wherein the humectant is present in a mass percentage of 0.1-10.0%.

[0015] In one embodiment, the moisturizer is sorbitol.

[0016] In one embodiment, the solvent is a mixture of alcohol and deionized water, wherein the alcohol has a mass percentage of 20.0-40.0% and the deionized water has a mass percentage of 20.0-30.0%.

[0017] In one embodiment, the alcohol is ethylene glycol.

[0018] In one embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0019] Detailed Implementation

[0020] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0021] Specifically, this invention discloses a water-based ink composition, which, by weight percentage, comprises the following components:

[0022]

[0023] The total content of all components is 100%.

[0024] To facilitate viscosity adjustment and improve the stability of printing results, the solvent of this invention is a mixture of alcohol and deionized water. The alcohol comprises 20.0-40.0% by weight, and the deionized water comprises 20.0-30.0% by weight. The alcohol can be any solvent capable of dissolving the colorant, including but not limited to ethanol, isopropanol, n-propanol, isobutanol, n-butanol, ethylene glycol, diethylene glycol, propylene glycol, glycerol, or mixtures thereof. Preferably, ethylene glycol is used in this invention.

[0025] In this invention, the colorant is a pigment, including but not limited to pigment black, pigment blue, and pigment yellow. Preferably, the colorant of this invention is a water-based self-dispersible pigment, the surface of which has hydrophilic groups, allowing it to be stably dispersed in an aqueous system. Specifically, the water-based self-dispersible pigment can be produced using existing chemical grafting or diazotization coupling methods, which will not be elaborated further in this invention.

[0026] To prolong the opening time, the water-based ink composition of the present invention includes a surfactant and a dispersant. The surfactant is selected as ethoxylated acetylene glycol, and the dispersant is selected as nonionic polyacrylamide and its derivatives. To further improve the stability of the ink, the water-based ink composition of the present invention also includes a bactericide, which is a bactericide with good compatibility with the water-based ink composition. Preferably, the bactericide of the present invention is MBS bactericide.

[0027] The additives of this invention include a pH adjuster and a humectant. The pH adjuster has a mass percentage of 0-5.0% and can be ethanolamine, urea, ammonia, etc.; the humectant has a mass percentage of 0-10.0% and can be sorbitol, diethylene glycol, glycerin, etc. Preferably, the pH adjuster is ethanolamine and the humectant is sorbitol.

[0028] Compared to existing technologies, this invention adds ethoxylated acetylene glycol and nonionic polyacrylamide and its derivatives to the water-based ink composition, which can form a dense film layer on the printhead surface, blocking the evaporation of internal volatiles, thereby greatly extending the ink cap opening time and improving printing efficiency.

[0029] To further understand the present invention, the water-based ink composition of the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited to the following embodiments.

[0030] The self-dispersible colorant is from Zhongke Huacai (Tianjin) Technology Development Co., Ltd., specification WP-210;

[0031] Evonik wetting agent 440 is from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0032] The amide dispersant SN-5040 is from Nopco Corporation of Japan, specification Nopco 5040;

[0033] BYK 340 is from BYK Chemicals Ltd.;

[0034] Tego715w is from Evonik Chemical GmbH, Germany, and its specification is TEGO Dispers 715W.

[0035] Tego735w is from Evonik Chemical GmbH, Germany, and its specification is TEGO Dispers 735W.

[0036] Dynol 960 is from Gas Chemicals, Inc., USA;

[0037] BYK 190 is from BYK Chemicals Ltd.;

[0038] Tego 410 is from Evonik Chemical GmbH, Germany.

[0039] Example 1

[0040] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0041]

[0042] The preparation process of the water-based ink composition is as follows:

[0043] Ethylene glycol and deionized water were added to the dispersion vessel and stirred until homogeneous. Then, Evonik wetting agent 440 and amide dispersant SN-5040 were added and stirred. Finally, self-dispersing pigment was added and stirred, filtered, and packaged.

[0044] Example 2

[0045] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0046]

[0047] The preparation process of the water-based ink composition is as follows:

[0048] Ethylene glycol and deionized water were added to the dispersion vessel and stirred. Sorbitol and ethanolamine were then added and stirred until homogeneous. Evonik wetting agent 440 and amide dispersant SN-5040 were added and stirred. Finally, self-dispersing pigment was added and stirred, filtered, and packaged.

[0049] Example 3

[0050] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0051]

[0052] The preparation process of the water-based ink composition is as follows:

[0053] Ethylene glycol and deionized water were added to the dispersion vessel and stirred until homogeneous. Then, Evonik wetting agent 440 and amide dispersant SN-5040 were added and stirred. Finally, self-dispersing pigment was added and stirred, filtered, and packaged.

[0054] Example 4

[0055] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0056]

[0057] The preparation process of the water-based ink composition is as follows:

[0058] Ethylene glycol and deionized water were added to the dispersion vessel and stirred. Then ethanolamine was added and stirred until homogeneous. Next, Evonik wetting agent 440, amide dispersant SN-5040 and MBS bactericide were added and stirred. Finally, self-dispersing color paste was added and stirred. The mixture was then filtered and packaged.

[0059] Example 5

[0060] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0061]

[0062] The preparation process of the water-based ink composition is as follows:

[0063] Ethylene glycol and deionized water were added to the dispersion vessel and stirred. Sorbitol was then added and stirred until homogeneous. Evonik wetting agent 440, amide dispersant SN-5040, and MBS bactericide were then added and stirred. Finally, self-dispersing color paste was added and stirred, filtered, and packaged.

[0064] Example 6

[0065] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0066]

[0067]

[0068] The preparation process of the water-based ink composition is as follows:

[0069] Ethylene glycol and deionized water were added to the dispersion vessel and stirred. Sorbitol and ethanolamine were then added and stirred until homogeneous. Evonik wetting agent 440, amide dispersant SN-5040 and MBS bactericide were then added and stirred. Finally, self-dispersing color paste was added and stirred, filtered, and packaged.

[0070] Example 7

[0071] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0072]

[0073] The preparation method of the water-based ink composition is the same as that in Example 6.

[0074] Example 8

[0075] In this embodiment, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0076]

[0077] The preparation method of the water-based ink composition is the same as that in Example 6.

[0078] Comparative Example 1

[0079] In this comparative example, the mass percentages of the water-based ink composition are as follows:

[0080]

[0081] The preparation method of the water-based ink composition is the same as that in Example 6.

[0082] Comparative Example 2

[0083] In this comparative example, the components of the water-based ink composition and the mass percentage of each component are as follows:

[0084]

[0085] The preparation method of the water-based ink composition is the same as that in Example 6.

[0086] Comparative Example 3

[0087] This comparative example is basically the same as Example 6, except that the surfactant used is polyether-modified organosilicon Tego410.

[0088]

[0089] Comparative Example 4

[0090] This comparative example is basically the same as Example 6, except that the dispersant used is the polyether compound Tego 735W.

[0091]

[0092] The water-based ink compositions prepared in Examples 1-8 and Comparative Examples 1-4 were subjected to the following performance tests, and the results are shown in Table 1.

[0093] Viscosity test: Data were obtained using a Brookfield DVPLUS viscometer at 25°C.

[0094] Surface tension test: Data were obtained using a Q2000 fully automatic surface tension meter / interfacial tension meter at 25℃.

[0095] Specific gravity test: Tested using a TWS-300 specific gravity meter at 25℃.

[0096] pH test: Data were obtained using a SevenDirect SD20 pH meter at 25°C.

[0097] Opening time test: Printing test was conducted on the PIJ digital inkjet printer. The maximum interval between the first and second ink prints was measured, which is the opening time of the ink cap.

[0098] High-speed printing performance: Printing was performed on a PIJ digital inkjet printer. The test was conducted on a rewinder at a speed of 90m / min for 100,000 consecutive prints to check for issues such as missing lines or ink bleeding.

[0099] Table 1 Performance Data of Water-Based Ink Compositions

[0100]

[0101]

[0102] As shown in Table 1, the opening time of the inks in Examples 1-8 of this invention is all above 90 minutes, with Example 6 reaching 150 minutes, representing a significant improvement compared to the comparative examples. Furthermore, the viscosity, specific gravity, pH value, and surface tension of the inks in Examples 1-8 of this invention are all within the required range for inkjet printers, while maintaining good high-speed printing performance. This indicates that the addition of ethoxylated acetylene glycol and nonionic polyacrylamide and its derivatives to the water-based ink composition of this invention can extend the opening time of the ink, and the water-based ink composition exhibits excellent overall performance.

[0103] Referring to Examples 1-6, it can be seen that the addition of bactericides, humectants, and pH adjusters in this invention further extends the opening time of the ink. This indicates that the bactericides, humectants, and pH adjusters can synergistically work with ethoxylated acetylene glycol and nonionic polyacrylamide and its derivatives to improve the ink's opening time.

[0104] Compared to Example 6, Comparative Example 1 does not contain ethoxylated acetylenic diol, Comparative Example 2 does not contain nonionic polyacrylamide and its derivatives, Comparative Example 3 uses other types of surfactants, and Comparative Example 4 uses other types of dispersants. In terms of opening time, the opening time of Example 6 is improved by at least 275%. Therefore, the combined effect of ethoxylated acetylenic diol and nonionic polyacrylamide and its derivatives in this invention is necessary to achieve the technical effect of extending the ink opening time.

[0105] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A water-based ink composition, characterized in that: By weight percentage, it consists of the following components: The total weight percentage of all components is 100%; wherein the surfactant is ethoxylated acetylenic diol and the dispersant is nonionic polyacrylamide and its derivatives.

2. The water-based ink composition according to claim 1, characterized in that: The water-based ink composition further includes a bactericide, wherein the bactericide is present in a weight percentage of 0.1-0.2%.

3. The water-based ink composition according to claim 2, characterized in that: The bactericide is MBS bactericide.

4. The water-based ink composition according to any one of claims 1-3, characterized in that: The water-based ink composition further includes a pH adjuster, wherein the pH adjuster is present in a mass percentage of 0.1-5.0%.

5. The water-based ink composition according to claim 4, characterized in that: The pH adjuster is ethanolamine.

6. The water-based ink composition according to any one of claims 1-3, characterized in that: The water-based ink composition further includes a humectant, wherein the humectant has a mass percentage of 0.1-10.0%.

7. The water-based ink composition according to claim 6, characterized in that: The moisturizer is sorbitol.

8. The water-based ink composition according to any one of claims 1-3, characterized in that: The solvent is a mixture of alcohol and deionized water, wherein the alcohol has a mass percentage of 20.0-40.0% and the deionized water has a mass percentage of 20.0-30.0%.

9. The water-based ink composition according to claim 8, characterized in that: The alcohol is ethylene glycol.

10. The water-based ink composition according to claim 1, characterized in that: The components and their mass percentages in the water-based ink composition are as follows:

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