Water-based ink

Abstract

The water-based ink is characterized by containing a synthetic resin, water, ethanol, a defoaming agent, a wetting agent, a dispersant, and a pigment.

Description

[Technical Field]

[0001] The present invention relates to a water-based ink. [Background technology]

[0002] Flexographic printing is a printing method in which ink is applied to an anilox roller and then transferred to a raised, engraved resin plate to print on a substrate. Flexographic printing has many advantages over other printing methods, especially gravure printing, including simpler and cheaper plate making and the ease of plate duplication, which allows for partial plate replacement. Due to its economy, it is also suitable for printing small lots and is used on a variety of materials. For example, flexographic techniques can be used to form printing layers on materials such as PE, PP, PVC, and PS.

[0003] Meanwhile, PP (Polypropylene) is a crystalline plastic that belongs to the polyolefin group and is used as a water-resistant base material for thin packaging sheets, pipe fittings, household items, etc. Flexographic printing on PP film currently uses a method of dissolving and printing with oil-based ink that contains strong solvents, which are harmful chemicals. However, unlike other films, the ink printed on PP is directly exposed to the outside, so the residual solvents in the ink have a significant impact on the environment and human health. Therefore, a technology is needed that can print and adhere PP film without using harmful chemicals or dissolving it.

[0004] Gravure printing is a method of printing ink onto a copper plate engraved with a recessed pattern, removing the rest of the ink with a doctor knife, and then printing the ink onto a film. Gravure printing is suitable for high-volume printing because it allows for high-speed printing and excellent reproducibility of type, letters, and designs. For example, gravure printing can be used to form a printed layer on packaging films such as PVC, PE, OPP, PET, and nylon. The gravure printing industry, which uses large amounts of hazardous organic solvents, is facing increasingly stringent regulations, including hydrocarbon emissions restrictions, the Fire Service Act, the Industrial Safety and Health Act, and the Chemical Substances Control Act. In response to this situation, domestic and international laws and regulations are being strengthened to restrict or ban the use of hazardous chemicals.

[0005] Ink used to print on PVC has excellent adhesion, can be thermally laminated, has excellent abrasion resistance, is odorless, and is light-resistant and durable, allowing it to be used in a variety of applications, including interior and floor renovation sheets. Traditionally, gravure printing on PVC has typically involved dissolving the PVC in oil-based ink containing strong solvents, which are harmful chemicals. However, this method leaves residual solvents after printing, which are harmful to the environment and humans. Therefore, a technology is needed for gravure printing on PVC that can print and adhere without using harmful chemicals and without dissolving the PVC roll.

[0006] Screen printing is a printing method in which printing materials such as ink or paste are squeezed through the openings of a screen printing plate by the sliding action of a squeegee, and the shape of the openings is transferred to the substrate to print the desired pattern. Screen printing is used in many industrial fields due to its high productivity, and in recent years has also been widely used in electronic products such as mobile phones, keypads, PDPs, and LCDs. Printing with a nozzle printer is a printing method that uses a printer to spray ink from a nozzle to print the results of computer work.

[0007] On the other hand, various designs can be printed on textiles such as cotton and silk using gravure printing, screen printing, and nozzle printer printing, but the most important factor in printing on such textiles is fastness to friction, washing, color, etc.

[0008] Currently, there are no water-based inks that can be printed on such textiles and meet the fastness requirements, which are important factors for printing on such textiles, and oil-based inks are used for industrial printing on textiles. Therefore, there is a need for water-based inks that can be printed on such textiles and meet the fastness requirements. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide a water-based ink that can be flexographically printed, adheres to print media, and is highly water-resistant without dissolving PP film or using harmful chemicals.

[0010] Also, embodiments of the present invention aim to provide a water-based ink that can be gravure printed and adhere to print media without hazardous chemicals and without dissolving PVC.

[0011] Another object of the present invention is to provide an aqueous ink for textiles that is capable of producing clear printing on textiles and has excellent fastness.

[0012] Another object of the present invention is to provide an ink that can be printed onto textiles in a variety of ways, including gravure printing, screen printing, and nozzle printer printing.

[0013] Also, embodiments of the present invention aim to provide a water-based ink that can be gravure printed and adhered to print media without hazardous chemicals and without dissolving shrink film. [Means for solving the problem]

[0014] The water-based ink according to an embodiment of the present invention may include a synthetic resin, water, ethanol, a defoaming agent, a wetting agent, a dispersant, and a pigment.

[0015] According to one embodiment, the synthetic resin is water-based urethane and water-based acrylic, and the composition includes 12.5 to 30 wt % of the water-based urethane, 5 to 10 wt % of the water-based acrylic, 20 to 37.5 wt % of the water, 10 to 20 wt % of the ethanol, 0.1 to 0.5 wt % of the defoaming agent, 0.1 to 0.5 wt % of the wetting agent, 2 to 4 wt % of the dispersant, and 10 to 15 wt % of the pigment, and the water-based ink may be for flexographic printing on the surface of a PP film.

[0016] According to one embodiment, the water-based ink further contains wax and includes a composition of 30 to 40 wt % of the synthetic resin, 17 to 46.8 wt % of the water, 10 to 20 wt % of the ethanol, 0.1 to 0.5 wt % of the defoaming agent, 0.1 to 0.5 wt % of the wetting agent, 2 to 4 wt % of the dispersant, 1 to 3 wt % of the wax, and 10 to 15 wt % of the pigment, wherein the synthetic resin includes water-based epoxy, water-based acrylic, or water-based urethane, and the water-based ink may be for gravure printing on a PVC surface.

[0017] According to one embodiment, the water-based ink further includes a wax and a fastness enhancer, and the synthetic resin is a water-based urethane and a water-based acrylic. The water-based ink may include a composition in the following proportions: 15 to 20 wt % of the water-based urethane, 25 to 30 wt % of the water-based acrylic, 17 to 36.7 wt % of the water, 10 to 20 wt % of the ethanol, 0.1 to 0.5 wt % of the defoaming agent, 0.1 to 0.5 wt % of the wetting agent, 2 to 4 wt % of the dispersant, 1 to 3 wt % of the wax, 10 to 15 wt % of the pigment, and 0.1 to 1 wt % of the fastness enhancer. The water-based ink may be for textiles.

[0018] According to one embodiment, the water-based ink further includes a slip agent, and the synthetic resin is water-based urethane and water-based acrylic, and includes a composition in the proportions of 10 to 15 wt % of the water-based urethane, 10 to 25 wt % of the water-based acrylic, 19.5 to 47 wt % of the water, 10 to 20 wt % of the ethanol, 0.1 to 0.5 wt % of the defoaming agent, 0.1 to 0.5 wt % of the wetting agent, 2 to 4 wt % of the dispersant, 10 to 15 wt % of the pigment, and 0.1 to 0.5 wt % of the slip agent, and the water-based ink may be for use in a shrink film.

[0019] According to an embodiment, the pigment may include at least one of an inorganic pigment and an organic pigment.

[0020] According to one embodiment, the wax may include polyethylene.

[0021] According to an embodiment, the fastness enhancer may include at least one of a silane and an alkyl group.

[0022] According to one embodiment, the pigment may include aluminum. [Effects of the Invention]

[0023] The water-based ink of the present invention is compatible with flexographic printing, adheres to print media, and is highly water-resistant, without dissolving PP film or using harmful chemicals.

[0024] Furthermore, the water-based ink of the present invention can be used for gravure printing without using harmful chemicals or dissolving PVC stock, and can adhere to the print medium.

[0025] Furthermore, the water-based ink of the present invention can provide a water-based ink for textiles that is capable of producing clear printing on textiles and has excellent fastness.

[0026] Additionally, the water-based inks of the present invention can be gravure printed and adhered to print media without hazardous chemicals or dissolving shrink film.

[0027] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a flowchart showing a method for producing a water-based ink for flexographic printing according to an embodiment of the present invention. [Figure 2] 1 is a flowchart showing a method for producing a water-based ink for gravure printing according to an embodiment of the present invention. [Figure 3] 1 is a flowchart illustrating a method for producing a water-based ink for textiles according to an embodiment of the present invention. [Figure 4] 1 is a flowchart illustrating a method for producing a water-based ink for a shrink film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] 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 several other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those having ordinary skill in the art. Therefore, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation, and elements denoted by the same reference numerals in the drawings are the same elements.

[0030] FIG. 1 is a flowchart showing a method for producing a water-based ink for flexographic printing according to an embodiment of the present invention.

[0031] Referring to Figure 1, the present invention relates to a method for manufacturing an aqueous ink for flexographic printing on a PP (Polypropylene) film. The manufacturing method includes a blending step, a dispersing step, and a mixing step. The aqueous ink includes a composition composed of an aqueous urethane, an aqueous acrylic, water, ethanol, a defoaming agent, a wetting agent, a dispersant, and a pigment, and may further include a dispersing resin.

[0032] The water-based urethane is printed on the film to maintain its adhesiveness, and in a preferred embodiment of the present invention, it is included in a composition ratio of 12.5 to 30% by weight.

[0033] The water-based acrylic serves to allow the water-based ink to adhere to the film, and may contain acrylic monomers such as acrylic acid, methyl methacrylate, etc. In a preferred embodiment of the present invention, the water-based acrylic is contained in a composition ratio of 5 to 10 wt %.

[0034] On the other hand, the water-based urethane and water-based acrylic help the ink adhere to the substrate and improve water resistance. Therefore, if the composition ratio of the water-based urethane and water-based acrylic is not appropriate, the adhesive strength and water resistance may decrease. For example, if the water-based acrylic is used in a ratio higher than the appropriate ratio, the water resistance of the ink will decrease.

[0035] Water is used as a solvent for the other components, and can be used in an amount of 20 to 37.5% by weight by adjusting the composition ratio as needed.

[0036] Ethanol increases the drying speed during printing, thereby increasing printing productivity. Ethanol is used as a solvent in inks and is not toxic, unlike conventional solvents such as toluene. Ethanol has the advantage of not remaining on the wrapping paper and evaporating as it dries during the printing process. In a preferred embodiment of the present invention, the ethanol is included in a composition ratio of 10 to 20% by weight.

[0037] The antifoaming agent prevents the generation of bubbles in the water during the dispersion process described below, ensuring smooth dispersion. The antifoaming agent also prevents bubbles from appearing in the printed material, ensuring accurate printing. In a preferred embodiment of the present invention, the antifoaming agent is included in a composition ratio of 0.1 to 0.5 wt %.

[0038] The wetting agent prevents the pigment from re-agglomerating, thereby helping to ensure accurate printing. In a preferred embodiment of the present invention, the wetting agent is contained in an amount of 0.1 to 0.5% by weight. The dispersant serves to disperse the pigment, prevent reagglomeration of the pigment, and maintain dispersibility. In a preferred embodiment of the present invention, the dispersant is contained in an amount of 2 to 4 wt %.

[0039] The pigment is a component that colors the water-based ink, and any pigment commonly used in the art can be used. Specifically, inorganic pigments such as carbon black and metal oxides, and organic pigments such as azo pigments, diazo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments can be used. Because the pigment is exposed to sunlight, a preferred embodiment of the present invention uses a pigment with high lightfastness, and more specifically, it is preferable to use a pigment with a lightfastness of grade 7 or higher. In a preferred embodiment of the present invention, the pigment is included in an amount of 10 to 15% by weight.

[0040] The water-based ink according to an embodiment of the present invention can adjust the color density of the ink depending on the amount of pigment contained therein, and can be used by adjusting the amount in the range of 10 to 15% by weight depending on the required color. The aqueous ink containing the above-mentioned composition and its manufacturing method are as follows.

[0041] The process includes a blending step (S11) of blending a dispersion resin, water, a dispersant, a defoamer, and a pigment, a dispersing step (S12) of dispersing the blend to prepare a base, and a mixing step (S13) of mixing water-based urethane, water-based acrylic, a wetting agent, and ethanol into the base.

[0042] In this case, the dispersing resin compounded in step (S11) chemically assists the dispersing action of the pigment in step (S12), and may include epoxy ester resin, vinyl-modified epoxy resin, high acid value alkyd resin, vinyl-modified resin, etc.

[0043] More specifically, in step (S12), the chemical dispersion is performed using a dispersion resin and a dispersant, and the physical dispersion is performed by milling using a bead mill, where milling refers to uniformly mixing and dissolving the composition by heat and mechanical action.

[0044] In this case, the composition ratio excluding the dispersing resin is 12.5 to 30 wt% aqueous urethane, 5 to 10 wt% aqueous acrylic, 20 to 37.5 wt% water, 10 to 20 wt% ethanol, 0.1 to 0.5 wt% antifoaming agent, 0.1 to 0.5 wt% wetting agent, 2 to 4 wt% dispersing agent, and 10 to 15 wt% pigment.

[0045] The present invention will be described in more detail below with reference to examples. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0046] [Example 1] The dispersion resin, water, dispersant, defoamer, and pigment were first blended and dispersed to prepare a base, after which the base was mixed with water-based urethane, water-based acrylic, wetting agent, and ethanol to prepare a water-based ink. The composition ratios of each component, excluding the dispersion resin, are shown in the following table.

[0047] [Table 1]

[0048] [Example 2] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0049] [Table 2]

[0050] [Example 3] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0051] [Table 3]

[0052] [Example 4] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0053] [Table 4]

[0054] [Example 5] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0055] [Table 5]

[0056] [Example 6] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0057] [Table 6]

[0058] [Example 7] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0059] [Table 7]

[0060] [Example 8] A water-based ink was produced in the same manner as in Example 1. The composition ratios of each component are as shown in the following table.

[0061] [Table 8]

[0062] [Comparative Example 1] The ink was prepared by mixing vinyl resin, urethane resin, pigment, and toluene in the composition ratios shown in the following table.

[0063] [Table 9]

[0064] [Test Example 1: Residual Solvent Detection Test] The inks of Examples 1 to 8 and Comparative Example 1 were used to print on PP film, and the presence or absence of residual solvent was confirmed.

[0065] [Table 10]

[0066] Test results showed that no residual solvent was left behind when printed with the water-based inks of Examples 1 to 8. The ink of Comparative Example 1 was shown to leave residual solvent.

[0067] [Test Example 2: Melting test of PP film] The inks of Examples 1 to 8 and Comparative Example 1 were used to print on a PP film having a thickness of 0.04 mm, and the thickness of the printed area of ​​the PP film was measured to confirm the degree to which the ink dissolved the PP film.

[0068] [Table 11]

[0069] The test results showed that when printing with the water-based inks of Examples 1 to 8, the printed area of ​​the PP film did not dissolve and maintained its thickness. When printing with the ink of Comparative Example 1, the thickness of the printed area of ​​the PP film decreased, indicating that printing was performed while dissolving the PP film.

[0070] [Test Example 3: Water Resistance Test] The inks of Examples 1 to 8 and Comparative Example 1 were applied to a PP film to a thickness of approximately 200 μm and dried at room temperature for approximately 24 hours to form a coating. The PP film was then immersed in water, and after 30 minutes, the coating was visually observed to determine whether it was water-soluble. If the coating was not water-soluble, it was evaluated as "good."

[0071] [Table 12]

[0072] The test results showed that the aqueous inks of Examples 1 to 8 and the ink of Comparative Example 1 had excellent water resistance because all of the coating films were insoluble in water. As shown in Test Examples 1 and 2, when an ink contains a strong solvent such as toluene, it dissolves the PP film during printing, leaving residual solvent behind after printing. As shown in Test Example 3, the aqueous ink for PP film according to the present invention had excellent water resistance.

[0073] As described above, the water-based ink of the present invention has excellent water resistance, can be printed without dissolving the PP film, and leaves no residual solvent after printing. Therefore, it eliminates the environmental and safety issues associated with oil-based inks containing strong solvents, which are harmful chemicals, and is a useful ink that can replace oil-based inks containing strong solvents.

[0074] FIG. 2 is a flowchart showing a method for producing a water-based ink for gravure printing according to an embodiment of the present invention.

[0075] 2, the present invention relates to a water-based ink for gravure printing on PVC surfaces and a method for manufacturing the same. The manufacturing method includes a compounding step, a dispersing step, and a mixing step. The water-based ink includes a composition consisting of a synthetic resin, water, ethanol, a defoaming agent, a wetting agent, a dispersant, wax, and a pigment, and may further include a dispersing resin.

[0076] The synthetic resin is the main substance that allows the ink to adhere to the substrate, and can include water-based epoxy, water-based acrylic, and water-based urethane. In a preferred embodiment of the present invention, the synthetic resin is included in a composition ratio of 30 to 40% by weight.

[0077] Water is used as a solvent for the other components, and can be used in an amount of 17 to 46.8% by weight by adjusting the composition ratio as needed.

[0078] Ethanol is added to the ink to improve its quick-drying properties. Ethanol is used as a solvent in the ink, and unlike conventional solvents such as toluene, it is not toxic and does not remain on the substrate. It evaporates during the printing process. In a preferred embodiment of the present invention, the ethanol is included in an amount of 10 to 20% by weight.

[0079] The antifoaming agent prevents the generation of bubbles in the water during the dispersion process described below, ensuring smooth dispersion. The antifoaming agent also prevents bubbles from appearing in the printed material, ensuring accurate printing. In a preferred embodiment of the present invention, the antifoaming agent is included in a composition ratio of 0.1 to 0.5 wt %.

[0080] The wetting agent prevents the pigment from re-agglomerating, thereby helping to ensure accurate printing. In a preferred embodiment of the present invention, the wetting agent is contained in an amount of 0.1 to 0.5% by weight.

[0081] The dispersant serves to disperse the pigment, prevent the pigment from agglomerating, and maintain the dispersibility. In a preferred embodiment of the present invention, the dispersant is contained in an amount of 2 to 4 wt %.

[0082] The wax improves the adhesive strength of the ink. In a preferred embodiment of the present invention, the wax contains polyethylene and is contained in an amount of 1 to 3% by weight.

[0083] The pigment is a component that provides color to the aqueous ink, and any pigment commonly used in the art can be used. Specifically, inorganic pigments such as carbon black and metal oxides, and organic pigments such as azo pigments, diazo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments can be used. In a preferred embodiment of the present invention, the pigment has high lightfastness and heat resistance. More specifically, it is preferred that the pigment has a lightfastness of grade 7 or higher and a heat resistance of 200°C or higher.

[0084] The water-based ink according to an embodiment of the present invention can adjust the color density of the ink depending on the amount of pigment contained therein, and can be used by adjusting the amount in the range of 10 to 15% by weight depending on the required color.

[0085] The aqueous ink containing the above-mentioned composition and its manufacturing method are as follows.

[0086] The process includes a blending step (S21) of blending a dispersion resin, water, a dispersant, an antifoaming agent, a pigment, and a wax, a dispersing step (S22) of dispersing the blend to prepare a base, and a mixing step (S23) of mixing a synthetic resin, a wetting agent, and ethanol into the base.

[0087] In this case, the dispersing resin compounded in step (S21) serves to chemically assist the pigment dispersion in step (S22), and may include epoxy ester resin, vinyl-modified epoxy resin, high acid value alkyd resin, vinyl-modified resin, etc.

[0088] More specifically, in step (S22), chemical dispersion is performed using a dispersing resin and a dispersing agent, and physical dispersion is performed by milling using a bead mill, where milling refers to uniformly mixing and dissolving the composition by heat and mechanical action.

[0089] In this case, the composition ratio excluding the dispersing resin is 30 to 40 wt% synthetic resin, 17 to 46.8 wt% water, 10 to 20 wt% ethanol, 0.1 to 0.5 wt% antifoaming agent, 0.1 to 0.5 wt% wetting agent, 2 to 4 wt% dispersing agent, 1 to 3 wt% wax, and 10 to 15 wt% pigment.

[0090] The present invention will be described in more detail below with reference to examples. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0091] [Example 9] A dispersion resin, water, a dispersant, a defoamer, a pigment, and a wax were blended and dispersed to prepare a base, and then a synthetic resin, a wetting agent, and ethanol were mixed with the base to prepare a water-based ink. The composition ratios of each component, excluding the dispersion resin, are shown in the following table.

[0092] [Table 13]

[0093] [Example 10] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0094] [Table 14]

[0095] [Example 11] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0096] [Table 15]

[0097] [Example 12] A water-based ink was prepared in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0098] [Table 16]

[0099] [Example 13] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0100] [Table 17]

[0101] [Example 14] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0102] [Table 18]

[0103] [Example 15] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0104] [Table 19]

[0105] [Example 16] A water-based ink was produced in the same manner as in Example 9. The composition ratios of each component are as shown in the following table.

[0106] [Table 20]

[0107] Comparative Example 2 The ink was prepared by mixing vinyl resin, urethane resin, pigment, and toluene in the composition ratios shown in the following table.

[0108] [Table 21]

[0109] [Test Example 4: Residual Solvent Detection Test] The inks of Examples 9 to 16 and Comparative Example 2 were used to print on PVC film, and the presence or absence of residual solvent was confirmed.

[0110] [Table 22]

[0111] Test results showed that no residual solvent was left behind when printed with the water-based inks of Examples 9 to 16. The ink of Comparative Example 2 was shown to leave residual solvent.

[0112] [Test Example 5: Melting test of PVC film] The inks of Examples 9 to 16 and Comparative Example 2 were used to print on a PVC film having a thickness of 0.04 mm, and the thickness of the printed area of ​​the PVC film was measured to confirm the degree to which the ink dissolves the PVC film.

[0113] [Table 23]

[0114] The test results showed that when printing was performed with the aqueous inks of Examples 9 to 16, the thickness of the printed area of ​​the PVC film was maintained because it did not dissolve. The ink of Comparative Example 2 reduced the thickness of the printed area of ​​the PVC film, indicating that printing occurred while dissolving the PVC film. As shown in Test Examples 4 and 5, inks containing strong solvents such as toluene dissolve the PVC film during printing, leaving residual solvent after printing. Thus, the aqueous ink of the present invention prints without dissolving the PVC film and leaves no residual solvent after printing, thereby eliminating the environmental and safety issues associated with oil-based inks containing strong solvents, which are hazardous chemicals. Therefore, the ink is a useful alternative to oil-based inks containing strong solvents.

[0115] FIG. 3 is a flowchart showing a method for producing a water-based ink for textiles according to an embodiment of the present invention.

[0116] The present invention relates to a water-based ink for textiles and a manufacturing method thereof, which includes a blending step, a dispersing step, and a mixing step. The water-based ink includes a composition composed of water-based urethane, water-based acrylic, water, ethanol, a defoaming agent, a wetting agent, a dispersant, wax, a pigment, and a fastness enhancer, and may further include a dispersing resin.

[0117] The aqueous urethane is printed on the substrate to maintain adhesiveness, and in a preferred embodiment of the present invention, it is contained in a composition ratio of 5 to 20% by weight.

[0118] The water-based acrylic helps the ink adhere to the substrate and may contain acrylic monomers such as acrylic acid, methyl methacrylate, etc. In a preferred embodiment of the present invention, the water-based acrylic is contained in a composition ratio of 25 to 30 wt %.

[0119] Water is used as a solvent for the other components, and can be used by adjusting the composition ratio appropriately within the range of 17 to 36.7%.

[0120] Ethanol is added to the ink to improve its quick-drying properties. Ethanol is used as a solvent in the ink, and unlike conventional solvents such as ethyl acetate and toluene, it is not toxic, does not remain on the fibers, and evaporates during the printing process. In a preferred embodiment of the present invention, the ethanol is included in a composition ratio of 10 to 20% by weight.

[0121] The antifoaming agent prevents the generation of bubbles in the water during the dispersion process described below, ensuring smooth dispersion. The antifoaming agent also prevents bubbles from appearing in the printed material, ensuring accurate printing. In a preferred embodiment of the present invention, the antifoaming agent is included in a composition ratio of 0.1 to 0.5 wt %.

[0122] The wetting agent prevents the pigment from re-agglomerating, thereby helping to ensure accurate printing. In a preferred embodiment of the present invention, the wetting agent is contained in an amount of 0.1 to 0.5% by weight.

[0123] The dispersant chemically disperses the pigment, prevents the pigment from agglomerating, and maintains its dispersibility. In a preferred embodiment of the present invention, the dispersant is contained in an amount of 2 to 4 wt %.

[0124] The wax improves the frictional slip of the printing surface when printed. In a preferred embodiment of the present invention, the wax contains polyethylene and is contained in a composition ratio of 1 to 3 wt %.

[0125] The pigment is a component that provides color to the aqueous ink, and any pigment commonly used in the art can be used. Specifically, inorganic pigments such as carbon black and metal oxides, and organic pigments such as azo pigments, diazo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments can be used. In a preferred embodiment of the present invention, the pigment has high lightfastness, and more specifically, it is preferred that the pigment has a lightfastness of grade 7 or higher.

[0126] The water-based ink for textiles according to one embodiment of the present invention can adjust the color density of the ink depending on the amount of pigment contained, and can be used by adjusting the amount in the range of 10 to 15 wt % depending on the required color. The fastness enhancer serves to improve the wash fastness and rub fastness of the ink. The fastness enhancer may include silane and alkyl groups, and in a preferred embodiment of the present invention, the fastness enhancer is included in an amount of 0.1 to 1 wt %.

[0127] The water-based ink for textiles containing the above-mentioned composition and its manufacturing method are as follows.

[0128] The process includes a blending step (S31) of blending a dispersion resin, water, a dispersant, an antifoaming agent, a pigment, and a wax, a dispersing step (S32) of dispersing the blend to prepare a base, and a mixing step (S33) of mixing a synthetic resin, a wetting agent, ethanol, and a fastness enhancer with the base.

[0129] In this case, the dispersing resin compounded in step (S31) serves to chemically assist the pigment dispersion in step (S32), and may include epoxy ester resin, vinyl-modified epoxy resin, high acid value alkyd resin, vinyl-modified resin, etc.

[0130] In addition, the synthetic resin is composed of water-based urethane and water-based acrylic, and the ink fastness may vary depending on the ratio. For example, if the ratio of the synthetic resin is not appropriate, the color may migrate when the printed matter printed with the synthetic resin is immersed in water.

[0131] More specifically, in step (S32), the chemical dispersion is performed using a dispersion resin and a dispersant, and the physical dispersion is performed by milling using a bead mill, where milling refers to uniformly mixing and dissolving the composition by heat and mechanical action.

[0132] In this case, the composition ratio excluding the dispersing resin is 15 to 20 wt% aqueous urethane, 25 to 30 wt% aqueous acrylic, 17 to 36.7% water, 10 to 20 wt% ethanol, 0.1 to 0.5 wt% antifoaming agent, 0.1 to 0.5 wt% wetting agent, 2 to 4 wt% dispersant, 1 to 3 wt% wax, 10 to 15 wt% pigment, and 0.1 to 1 wt% fastness enhancer.

[0133] The present invention will be described in more detail below with reference to examples. However, these examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0134] [Example 17] A dispersion resin, water, dispersant, defoamer, pigment, and wax were first blended and dispersed to prepare a base. Then, a synthetic resin, a wetting agent, ethanol, and a fastness enhancer were mixed with the base to prepare a water-based textile ink. The synthetic resin was composed of water-based urethane and water-based acrylic, and the composition ratios of each component, excluding the dispersion resin, were as shown in the following table.

[0135] [Table 24]

[0136] [Example 18] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0137] [Table 25]

[0138] [Example 19] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0139] [Table 26]

[0140] [Example 20] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0141] [Table 27]

[0142] [Example 21] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0143] [Table 28]

[0144] [Example 22] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0145] [Table 29]

[0146] [Example 23] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0147] [Table 30]

[0148] [Example 24] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0149] [Table 31]

[0150] [Example 25] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0151] [Table 32]

[0152] [Example 26] A water-based textile ink was prepared in the same manner as in Example 17. The composition ratios of each component are as shown in the following table.

[0153] [Table 33]

[0154] Comparative Example 3 The ink was prepared by mixing vinyl resin, urethane resin, pigment, and ethanol in the composition ratios shown in the following table.

[0155] [Table 34]

[0156] [Test Example 6: Fastness Evaluation] The inks of Examples 1 to 10 and Comparative Example 1 were refilled into cartridges of an industrial printer VJ-1924 (MUTOH Corporation) equipped with an Epson DX7 printhead, and printing was performed. The print conditions were monochrome, 720 x 720 resolution, and 4 passes. The original fabric was printed onto a roll-type CM40 plain weave cotton fabric, which was then hot-pressed at 180°C for 3 minutes. The prints were then cut to meet the evaluation standards and evaluated for colorfastness. The resulting prints were tested in accordance with KSK ISO 105-X06:2014 (A1S method), and the degree of discoloration and staining was assessed using a standard gray color chart, resulting in a rating of 1 to 5. Grade 1 represents the most severe color fading, and grades closer to grade 5 represent the least severe color fading.

[0157] At the same time, the produced printed textiles are evaluated in accordance with KSK ISO 105-X12:2016 (Crockmeter method), and the degree of contamination is determined using a standard gray color chart and graded from 1 to 5, with grade 5 being the best.

[0158] [Table 35]

[0159] As a result, as can be seen in Table 35, the inks of Examples 17 to 26 according to the present invention show similar light fastness, washing fastness, and rubbing fastness to the ink of Comparative Example 3 prepared using a conventional ink composition. Therefore, the water-based ink for textiles according to the present invention can be expected to have excellent fastness and stability, and is a useful ink that can replace oil-based inks.

[0160] FIG. 4 is a flowchart showing a method for producing a water-based ink for shrink film according to an embodiment of the present invention.

[0161] The present invention relates to a water-based ink for shrink films and a manufacturing method thereof, which includes a blending step, a dispersing step, and a mixing step. The water-based ink includes a composition composed of water-based urethane, water-based acrylic, water, ethanol, a defoaming agent, a wetting agent, a dispersant, a pigment, and a slip agent, and may further include a dispersing resin.

[0162] The water-based urethane is printed on the film to maintain its adhesiveness, and in a preferred embodiment of the present invention, it is included in a composition ratio of 10 to 15% by weight.

[0163] The water-based acrylic helps the ink adhere to the film and may contain acrylic monomers such as acrylic acid, methyl methacrylate, etc. In a preferred embodiment of the present invention, the water-based acrylic is contained in a composition ratio of 10 to 25 wt %.

[0164] Meanwhile, the water-based urethane and water-based acrylic help the ink adhere to the film, so if the ratio of the water-based urethane and water-based acrylic changes, the adhesive strength decreases, which can cause problems in the subsequent process of making shrink labels after printing.

[0165] Water is used as a solvent for the other components, and can be used in an amount of 19.5 to 47% by weight by adjusting the composition ratio as needed.

[0166] Ethanol is added to the ink to improve its quick-drying properties. Unlike conventional solvents such as toluene, ethanol is not toxic and does not remain on the paper wrapper. It evaporates during the printing process. In a preferred embodiment of the present invention, ethanol is included in the ink at a composition ratio of 10 to 20% by weight.

[0167] The antifoaming agent prevents the generation of bubbles in water during the dispersion process described below, ensuring smooth dispersion. The antifoaming agent also prevents bubbles from appearing in the printed material, ensuring accurate printing. In a preferred embodiment of the present invention, the antifoaming agent is included in a composition ratio of 0.1 to 0.5 wt %.

[0168] The wetting agent prevents the pigment from reagglomerating and helps ensure accurate printing. In a preferred embodiment of the present invention, the wetting agent is included in an amount of 0.1 to 0.5% by weight. The dispersant serves to disperse the pigment, prevent the pigment from agglomerating, and maintain the dispersibility. In a preferred embodiment of the present invention, the dispersant is contained in an amount of 2 to 4 wt %.

[0169] The pigment is a component that colors the ink, and any pigment commonly used in the art can be used. Specifically, inorganic pigments such as carbon black and metal oxides, and organic pigments such as azo pigments, diazo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments can be used. Aluminum can also be used depending on the color of the ink.

[0170] The water-based ink for shrink film according to the present invention can adjust the color density of the ink depending on the amount of pigment contained therein, and can be used in a range of 10 to 15% by weight depending on the required color.

[0171] The slip agent serves to reduce friction when the shrink film is wrapped around the container. In a preferred embodiment of the present invention, the slip agent is a silicone slip agent, and is included in an amount of 0.1 to 0.5 wt % of the composition.

[0172] The water-based ink for shrink film containing the above-mentioned composition and its manufacturing method are as follows.

[0173] The process includes a blending step (S41) of blending dispersion resin, water, dispersant, defoamer, and pigment, a dispersing step (S42) of dispersing the blend to prepare a base, and a mixing step (S43) of mixing water-based urethane, water-based acrylic, wetting agent, ethanol, and slip agent into the base.

[0174] In this case, the dispersing resin compounded in step (S41) serves to chemically assist the pigment dispersion in step (S42), and may include epoxy ester resin, vinyl-modified epoxy resin, high acid value alkyd resin, vinyl-modified resin, etc.

[0175] More specifically, in step (S42), chemical dispersion is performed using a dispersing resin and a dispersing agent, and physical dispersion is performed by milling using a bead mill, where milling refers to uniformly mixing and dissolving the composition by heat and mechanical action.

[0176] In this case, the composition ratio excluding the dispersing resin is 10 to 15 wt% of aqueous urethane, 10 to 25 wt% of aqueous acrylic, 19.5 to 47 wt% of water, 10 to 20 wt% of ethanol, 0.1 to 0.5 wt% of antifoaming agent, 0.1 to 0.5 wt% of wetting agent, 2 to 4 wt% of dispersing agent, 10 to 15 wt% of pigment, and 0.1 to 0.5 wt% of slip agent.

[0177] The present invention will be described in more detail below with reference to examples. However, these examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0178] [Example 27] The dispersion resin, water, dispersant, defoamer, and pigment were first blended and dispersed to prepare a base. The base was then mixed with water-based urethane, water-based acrylic, wetting agent, ethanol, and slip agent to prepare a water-based ink for shrink film. The composition ratios of each component, excluding the dispersion resin, are shown in the following table.

[0179] [Table 36]

[0180] [Example 28] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0181] [Table 37]

[0182] [Example 29] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0183] [Table 38]

[0184] [Example 30] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0185] [Table 39]

[0186] [Example 31] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0187] [Table 40]

[0188] [Example 32] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0189] [Table 41]

[0190] [Example 33] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0191] [Table 42]

[0192] [Example 34] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0193] [Table 43]

[0194] [Example 35] A water-based ink for shrink film was prepared in the same manner as in Example 27. The composition ratios of each component are as shown in the following table.

[0195] [Table 44]

[0196] Comparative Example 4 The ink was prepared by mixing vinyl resin, urethane resin, pigment, and toluene in the composition ratios shown in the following table.

[0197] [Table 45]

[0198] [Test Example 7: Residual Solvent Detection Test] The inks of Examples 27 to 35 and Comparative Example 4 were used to print on shrink film, and the presence or absence of residual solvent was confirmed.

[0199] [Table 46]

[0200] Test results showed that no residual solvent was left behind when printed with the water-based shrink film inks of Examples 27 to 35. The ink of Comparative Example 1 was shown to leave residual solvent.

[0201] [Test Example 8: Melting test of shrink film] The inks of Examples 27 to 35 and Comparative Example 4 were used to print on a PVC shrink film having a thickness of 0.04 mm, and the thickness of the printed area of ​​the shrink film was measured to confirm the degree to which the ink dissolved the shrink film.

[0202] [Table 47]

[0203] The test results showed that when printing was performed with the aqueous inks for shrink film of Examples 27 to 35, the thickness of the printed area of ​​the shrink film was maintained because it did not dissolve. The ink of Comparative Example 4 reduced the thickness of the printed area of ​​the shrink film, indicating that printing was performed while dissolving the shrink film.

[0204] As shown in Test Examples 7 and 8, when an ink contains a strong solvent such as toluene, the shrink film is dissolved during printing, and residual solvent remains after printing. As such, the water-based ink for shrink film of the present invention prints without dissolving the shrink film and leaves no residual solvent after printing, thereby eliminating the environmental and safety issues associated with oil-based inks containing strong solvents and making it a useful ink that can replace oil-based inks containing strong solvents.

[0205] Meanwhile, the embodiments of the present invention disclosed in this specification and the drawings are merely specific examples presented to facilitate understanding of the present invention by easily explaining the technical content of the present invention, and are not intended to limit the scope of the present invention. It will be obvious to those skilled in the art to which the present invention pertains that other modifications based on the technical concept of the present invention can be implemented in addition to the embodiments disclosed herein. [Industrial Applicability]

[0206] The water-based ink of the present invention is compatible with flexographic printing, adheres to print media, and is highly water-resistant, without dissolving PP film or using harmful chemicals.

[0207] Furthermore, the water-based ink of the present invention can be used for gravure printing without using harmful chemicals or dissolving PVC stock, and can adhere to the print medium.

[0208] Furthermore, the water-based ink of the present invention can provide a water-based ink for textiles that is capable of producing clear printing on textiles and has excellent fastness.

[0209] Additionally, the water-based ink of the present invention can be gravure printed and adhered to print media without hazardous chemicals or dissolving shrink film.

Claims

1. Contains synthetic resin, water, ethanol, defoamer, wetting agent, dispersant and pigment A water-based ink characterized by:

2. The synthetic resin is a water-based urethane and a water-based acrylic, The composition comprises 12.5 to 30% by weight of the water-based urethane, 5 to 10% by weight of the water-based acrylic, 20 to 37.5% by weight of the water, 10 to 20% by weight of the ethanol, 0.1 to 0.5% by weight of the defoaming agent, 0.1 to 0.5% by weight of the wetting agent, 2 to 4% by weight of the dispersant, and 10 to 15% by weight of the pigment, For flexographic printing on the surface of PP film The aqueous ink of claim 1.

3. Further comprising wax, the composition comprising 30 to 40% by weight of the synthetic resin, 17 to 46.8% by weight of the water, 10 to 20% by weight of the ethanol, 0.1 to 0.5% by weight of the defoaming agent, 0.1 to 0.5% by weight of the wetting agent, 2 to 4% by weight of the dispersant, 1 to 3% by weight of the wax, and 10 to 15% by weight of the pigment; The synthetic resin includes water-based epoxy, water-based acrylic, and water-based urethane; For gravure printing on the surface of PVC The aqueous ink of claim 1.

4. further comprising waxes and fastness enhancers; The synthetic resin is a water-based urethane and a water-based acrylic, The composition comprises 15 to 20% by weight of the water-based urethane, 25 to 30% by weight of the water-based acrylic, 17 to 36.7% by weight of the water, 10 to 20% by weight of the ethanol, 0.1 to 0.5% by weight of the defoaming agent, 0.1 to 0.5% by weight of the wetting agent, 2 to 4% by weight of the dispersant, 1 to 3% by weight of the wax, 10 to 15% by weight of the pigment, and 0.1 to 1% by weight of the fastness enhancer, and is for use in fibers. The aqueous ink of claim 1.

5. further comprising a slip agent; The synthetic resin is a water-based urethane and a water-based acrylic, the composition comprising 10 to 15% by weight of the water-based urethane, 10 to 25% by weight of the water-based acrylic, 19.5 to 47% by weight of the water, 10 to 20% by weight of the ethanol, 0.1 to 0.5% by weight of the defoaming agent, 0.1 to 0.5% by weight of the wetting agent, 2 to 4% by weight of the dispersant, 10 to 15% by weight of the pigment, and 0.1 to 0.5% by weight of the slip agent; For shrink film The aqueous ink of claim 1.

6. The pigment includes at least one of an inorganic pigment and an organic pigment. The aqueous ink of claim 1.

7. The wax comprises polyethylene. The aqueous ink according to claim 3 or 4.

8. The fastness enhancer includes at least one of a silane and an alkyl group. The aqueous ink according to claim 4.

9. The pigment contains aluminum The aqueous ink according to claim 5.

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