Water-based offset printing ink and preparation method thereof

Abstract

The present invention relates to an aqueous offset ink which can improve the atmospheric environment, provide an environmentally friendly printing environment, produce non-toxic printed matters and maintain the advantages of adhesion, water resistance, wear resistance and the like of synthetic resin, as an aqueous ink using aqueous acrylic acid, aqueous urethane and polyester, and a method for preparing the same.

Description

Technical Field

[0001] The present invention relates to a water-based offset printing ink and a preparation method thereof, and in particular to a water-based offset printing ink which uses water-based acrylic acid, water-based urethane and polyester to improve the atmospheric environment, provide an environmentally friendly printing environment and produce non-toxic printed products while maintaining the advantages of adhesion, water resistance and wear resistance of synthetic resin and a preparation method thereof. Background Art

[0002] Generally, paper printing is done by transferring ink onto a flat plate. Offset printing is used in a wide range of industrial fields, including printed materials and product packaging, so the amount of offset printing ink used in offset printing is very high.

[0003] Generally speaking, the components of offset printing ink are composed of oily materials such as pigments, resins, vegetable oils, petroleum organic solvents, and additives.

[0004] It is known that petroleum-based organic solvents used in offset printing can cause various environmental problems, especially the generation of volatile organic compounds (VOCs), and have harmful effects on the health of workers in the printing industry who use organic solvents and those who are exposed to organic solvents.

[0005] Recently, due to such environmental and health issues, efforts have been made to apply technologies and inks that can replace oil-based inks. However, in terms of technologies that meet the environmental protection, printing quality, and printing process efficiency of printing inks, since the offset printing method uses the chemical properties of oil and water repelling each other, the development of water-based inks is not mature yet.

[0006] When the offset printing process does not contain petroleum-based organic solvents, contrary to the hydrophobic properties of the offset printing method, that is, contrary to the property of repelling water and not mixing with water, it is necessary to develop technology that can maintain printing quality even without containing oil-based ink organic solvents.

[0007] There is a need to develop a commercially viable offset printing ink that is water-based and has environmental friendliness, printing process efficiency, and print quality.

[0008] On the other hand, authorized patent No. 10-1927730 discloses an environmentally friendly offset printing ink and a preparation method thereof. The environmentally friendly offset printing ink does not contain hydroquinone and petroleum-based organic solvents, and its composition is a mixture of 20 weight percent to 40 weight percent of a first rosin-modified phenolic resin binder, 10 weight percent to 30 weight percent of a second rosin-modified phenolic resin binder, 10 weight percent to 30 weight percent of a third rosin-modified phenolic resin binder; 5 weight percent to 25 weight percent of a pigment and 1 weight percent to 3 weight percent of a cyclodextrin-metal desiccant and the remaining weight percent of fatty acid methyl ester as a solvent. Summary of the invention

[0009] Technical issues

[0010] The purpose of the embodiments of the present invention is to provide a commercially available aqueous ink for offset printing and a preparation method thereof, which is non-toxic and odorless and can achieve environmental protection, improve the working environment of workers, and exhibit printing process efficiency and good printing quality.

[0011] Technical Solution

[0012] The water-based offset printing ink of the present invention is characterized in that it consists of 10 to 20 weight percent of water-based acrylic acid, 20 to 30 weight percent of water-based ethyl formate, 10 to 15 weight percent of polyester, 20 to 40 weight percent of water, 5 to 10 weight percent of ethanol, 10 to 20 weight percent of pigment and 0.5 to 5 weight percent of additives.

[0013] Effects of the Invention

[0014] The present invention is free from the components of existing oil-based offset printing inks, and uses water-based materials such as water-based acrylic acid, water-based urethane and polyester as water-based inks, which can improve the atmospheric environment, provide an environmentally friendly printing environment, and produce non-toxic printed products. In addition, the present invention maintains the advantages of synthetic resins such as adhesion, water resistance, and wear resistance.

[0015] The water-based offset ink of the present invention has excellent adhesion to various substrates, can appropriately adjust the drying speed, and unlike the existing oil-based offset ink, does not generate volatile organic compounds (VOCs) and can be used interchangeably in printing devices for oil-based offset inks.

[0016] On the other hand, in the present invention, the types of resins included in the composition are water-based acrylic, water-based urethane, and polyester, and thus the present invention has an advantage of being easy to supply raw materials.

[0017] The effects of the present invention are not limited to the effects described above, and a person skilled in the art to which the present invention belongs can clearly understand other effects not mentioned through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The flowchart is a method for preparing a water-based offset printing ink according to an embodiment of the present invention.

[0019] Figure 2 The figure shows the bleeding experiment of the water-based offset ink according to the embodiment of the present invention.

[0020] Figure 3 The figure shows the bleeding experiment of the water-based offset ink according to the embodiment of the present invention. DETAILED DESCRIPTION

[0021] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into a variety of other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more completely describe the present invention to a person of ordinary skill in the art. Therefore, in order to more clearly describe, the shapes and sizes of the elements in the accompanying drawings may be exaggerated, and the elements represented by the same reference numerals in the accompanying drawings are the same elements.

[0022] Figure 1 The present invention is a flowchart showing a method for preparing a water-based offset printing ink according to an embodiment of the present invention. Figure 2 The figure shows the bleeding experiment of the water-based offset ink according to the embodiment of the present invention.

[0023] The invention relates to a water-based offset printing ink and a preparation method thereof. The structural elements of the ink composition include water-based acrylic acid, water-based urethane, polyester, water, ethanol, pigment and additives.

[0024] The water-based acrylic resin is an acrylic resin with water as solvent, and may contain acrylic monomers such as acrylic acid and methyl methacrylate. The water-based acrylic resin can improve the weather resistance of the ink, prevent the ink from deteriorating under various climatic conditions, and help improve the glossiness. In addition, the water-based acrylic resin can increase the wear resistance of the ink and help improve its adhesion. In a preferred embodiment of the present invention, the composition ratio of the water-based acrylic resin is 10 to 30 weight percent.

[0025] The water-based urethane resin is a urethane resin using water as a solvent, and is used to maintain its adhesion. In a preferred embodiment of the present invention, the composition ratio of the water-based urethane resin is 20 to 30 weight percent.

[0026] Water (H2O) is a solvent for the resin and helps to stabilize the ink. In a preferred embodiment of the present invention, the composition ratio of water is 20 to 40 weight percent.

[0027] The polyester imparts flexibility to the synthetic resin, enabling it to adhere well to the fabric. In a preferred embodiment of the present invention, the polyester comprises 10 to 15 weight percent.

[0028] Ethanol is a medium for dissolving resin and water, and plays a role in making the ink mix well. In a preferred embodiment of the present invention, the composition ratio of the ethanol is 5 to 10 weight percent.

[0029] The pigment determines the color of the ink, and various colors of pigments can be used, and the depth of the ink color can be adjusted according to the amount of the pigment included. In a preferred embodiment of the present invention, the composition ratio of the pigment is 10 to 20 weight percent, and the color of the ink is determined by the weight ratio of the pigment, so the pigment weight ratio is determined by the ink of the desired color, and thus, the overall composition ratio is determined by adjusting the weight ratio of the remaining components.

[0030] In addition, the water-based ink used in the present invention further comprises an additive. The additive is used to ensure that the water-based ink has excellent printing characteristics and can be added in a small amount. In detail, the additive comprises a dispersant, a defoamer, a wax (WAX), and a leveling agent. The dispersant provides a dispersion effect and a surface active effect for the colorant, the defoamer is used to prevent bubbles generated during the ink preparation process, the wax (WAX) is used to prevent the ink from being dirty and improve the gloss of the ink, and the leveling agent improves the leveling property by adjusting the surface tension of the ink surface and ensures storage stability and improves the quality.

[0031] The key to the embodiments of the present invention lies in the composition ratio of the constituent substances. Since offset ink utilizes the property that water and ink do not mix and repel each other, the present invention needs to be directly applicable to commonly used offset printing presses and maintain the same quality as existing oil-based inks. In the offset printing process, if the repulsive force is insufficient or the transmission force to the printing plate and the rubber roller is poor, the printing quality will decrease, but even if it is water-based ink, according to the composition ratio of the embodiments of the present invention, the printing quality is still maintained at a certain level.

[0032] The preparation method of the water-based offset printing ink with the composition ratio as described above is as follows. The preparation method comprises the following steps: stirring 10 to 30 weight percent of water-based acrylic acid, 20 to 30 weight percent of water-based urethane, and 20 to 40 weight percent of water to form a stirred product; mixing 5 to 10 weight percent of ethanol, 10 to 15 weight percent of polyester, 10 to 20 weight percent of pigment, and 0.5 to 5 weight percent of additives with the stirred product to form a mixture; and grinding the mixture.

[0033] In this context, milling refers to uniformly mixing and grinding a composition by heat and mechanical action.

[0034] On the other hand, the embodiments of the preparation method of the present invention can be carried out under heating or pressure, and the temperature needs to be maintained between room temperature and 200 degrees Celsius from the initial stirring step to the grinding step.

[0035] Hereinafter, the present invention will be described in more detail by way of examples. However, these examples are for illustrative purposes only and the scope of the present invention is not limited to these examples.

[0036] Example 1

[0037] First, water-based acrylic acid, water-based urethane, and water are stirred, ethanol, polyester, pigment, and additives are mixed therein, and then the mixture is ground to prepare a water-based offset printing ink. The composition ratio of each component is shown in the following table.

[0038] Table 1

[0039] Element Weight Percent Water-based acrylic 13 Water-based urethane 20 Polyester 11 water 40 Ethanol 5 pigment 10 additive 1

[0040] Example 2

[0041] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0042] Table 2

[0043]

[0044]

[0045] Example 3

[0046] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0047] Table 3

[0048] Element Weight Percent Water-based acrylic 29 Water-based urethane 20 Polyester 10 water 20 Ethanol 10 pigment 10 additive 1

[0049] Example 4

[0050] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0051] Table 4

[0052] Element Weight Percent Water-based acrylic 14 Water-based urethane 20 Polyester 10 water 40 Ethanol 5 pigment 10 additive 1

[0053] Example 5

[0054] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0055] Table 5

[0056]

[0057]

[0058] Example 6

[0059] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0060] Table 6

[0061] Element Weight Percent Water-based acrylic 10 Water-based urethane 24 Polyester 10 water 40 Ethanol 5 pigment 10 additive 1

[0062] Example 7

[0063] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0064] Table 7

[0065]

[0066]

[0067] Example 8

[0068] A water-based offset printing ink was prepared in the same manner as in Example 1. The composition ratio of each component is shown in the following table.

[0069] Table 8

[0070] Element Weight Percent Water-based acrylic 15 Water-based urethane 30 Polyester 14 water 20 Ethanol 10 pigment 10 additive 1

[0071] Comparative Example 1

[0072] A water-based offset printing ink was prepared in the same manner as in Comparative Example 1. The composition ratio of each component is shown in the following table.

[0073] Table 9

[0074] Element Weight Percent Water-based acrylic 21 Water-based urethane 11 Polyester 11 water 45 Ethanol 1 pigment 10 additive 1

[0075] Experimental Example 1: Color bleeding experiment

[0076] The water-based offset inks of Examples 1 to 8 and Comparative Example 1 were printed on paper and checked for bleeding.

[0077] Table 10

[0078]

[0079] The experimental results show that when the water-based offset inks of Examples 1 to 8 are used for printing, no bleeding occurs during the printing process, so the bleeding characteristics are good. The water-based offset ink of Comparative Example 1 bleeds, so its bleeding characteristics are worse than those of the Examples. Figures 2 to 3 This is a photograph of the evaluation of bleeding characteristics based on ethanol content in Experimental Example 1. The contents of the components other than ethanol and water are the same. Example 1 with an ethanol content of 5 weight percent and Comparative Example 1 with an ethanol content of 1 weight percent are printed on paper to confirm whether bleeding occurs. As shown in the figure, it can be seen that the bleeding quality decreases with the ethanol content. Therefore, printing with water-based offset ink may have an adverse effect on the printing quality, so the reasonable ethanol content is more than 5 weight percent. Figure 2 The importance of the composition ratio of the embodiment of the present invention is shown, and it is shown that the embodiment of the present invention can be applied to the offset printing device like the existing oil-based ink.

[0080] As described above, the water-based offset ink of the present invention can solve the environmental and safety problems caused by oil-based offset inks, and at the same time exhibits excellent printability, color bleeding characteristics and other physical properties that are not inferior to oil-based offset inks. It is a useful ink that can replace oil-based offset inks.

[0081] On the other hand, the embodiments of the present invention disclosed in this specification and the drawings are only specific examples for the convenience of explaining the technical content of the present invention and helping to understand the present invention, and are not intended to limit the scope of the present invention. It is obvious to a person skilled in the art that in addition to the embodiments disclosed herein, other variations based on the technical ideas of the present invention may also be implemented.

[0082] Industrial Applicability

[0083] The present invention is free from the components of existing oil-based offset printing inks. As a water-based ink using water-based materials such as water-based acrylic acid, water-based urethane and polyester, it can improve the atmospheric environment, provide an environmentally friendly printing environment, and produce non-toxic printed products, while maintaining the advantages of synthetic resins such as adhesion, water resistance and wear resistance.

Claims

1. A water-based offset printing ink, wherein the offset printing ink does not contain a petroleum-based organic solvent, characterized in that: The invention comprises 10 to 30 weight percent of water-based acrylic acid, 20 to 30 weight percent of water-based urethane, 10 to 15 weight percent of polyester, 20 to 40 weight percent of water, 5 to 10 weight percent of ethanol, 10 to 20 weight percent of pigment and 0.5 to 5 weight percent of additives.

2. The water-based offset printing ink according to claim 1, characterized in that: The additives include a dispersant.

3. The water-based offset printing ink according to claim 1, characterized in that: The additives include a defoamer.

4. The water-based offset printing ink according to claim 1, characterized in that: The additive comprises wax.

5. The water-based offset printing ink according to claim 1, characterized in that: The additives include a leveling agent.

6. A method for preparing a water-based offset printing ink, wherein the offset printing ink does not contain a petroleum-based organic solvent, characterized in that: The steps include: Stirring 10 to 30 weight percent of aqueous acrylic acid, 20 to 30 weight percent of aqueous urethane, and 20 to 40 weight percent of water to form a stirred product; Mixing 5 to 10 weight percent of ethanol, 10 to 15 weight percent of polyester, 10 to 20 weight percent of pigment, and 0.5 to 5 weight percent of additives with the stirred product to form a mixture; and The mixture was ground.

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