Pure water-based ink for thin film, preparation method of pure water-based ink and application of pure water-based ink in intaglio printing and flexographic printing

Abstract

The invention provides pure water-based ink for a thin film, a preparation method of the pure water-based ink and application of the pure water-based ink in intaglio printing and flexographic printing, and belongs to the technical field of pure water-based ink. According to the invention, the acrylic acid water-soluble resin is used as a binder to disperse and stabilize the pigment; the surface active agent is used for reducing the surface tension of the pure water-based ink and cooperating with the dispersing agent, the pigment and the filler are prevented from being agglomerated and precipitated, the quality and performance of the pure water-based ink are kept, the storage stability of the pure water-based ink is improved, and meanwhile the dispersing agent adjusts the viscosity and improves the fluidity of the pure water-based ink, so that the pure water-based ink is more easily and uniformly coated on a printing stock; the defoaming agent inhibits formation of foam, the coating performance of the pure water-based ink is remarkably improved, a uniform coating film can be formed, and the printing quality and efficiency are improved; the acrylic acid coupling agent can improve the compatibility among the components in the pure water-based ink and improve the uniformity and stability of the pure water-based ink, and finally the pure water-based ink which does not contain an organic solvent, can be printed on a film and is suitable for intaglio printing and flexographic printing is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of water-based ink, and in particular to a pure water-based ink for a film, a preparation method thereof, and applications of the pure water-based ink in gravure printing and flexographic printing. Background Art

[0002] Water-based ink is referred to as water ink. Currently, both water-based ink and oil-based ink are widely used in the printing industry. They each have their own unique advantages and disadvantages, and there are significant differences. The advantages of oil-based ink are: (1) Excellent color performance. Oil-based ink can achieve bright colors and high saturation, which is suitable for high-quality printing needs; (2) Strong adhesion. It has good adhesion performance on a variety of surface materials, especially on paper and certain plastics; (3) Strong weather resistance: After drying, oil-based ink has strong tolerance to humidity and temperature changes, and is suitable for outdoor applications. However, oil-based ink has problems such as poor environmental protection and troublesome cleaning. The VOC generated during the use of oil-based ink may have a certain impact on the environment and human health. The cleaning of oil-based ink is relatively complicated and often requires the use of special cleaning agents.

[0003] Compared with oil-based ink, water-based ink is more environmentally friendly and has a very low VOC (volatile organic compound) content, which helps reduce the negative impact on the environment and is less harmful to the human body. It will not harm the health of ink manufacturers and printing operators, and improves environmental quality. Water-based ink can usually be cleaned with water and soap, which is convenient for equipment maintenance and reduces cleaning costs. Water-based ink has stable ink properties, does not corrode the plate, is easy to operate, is cheap, has good adhesion after printing, and is highly water-resistant. However, water-based ink also has disadvantages: (1) The color performance is relatively weak. In terms of color depth and saturation, water-based ink is not as good as oil-based ink, especially when applied to some special materials; (2) The weather resistance is poor. Water-based ink has weak weather resistance and may not be suitable for long-term outdoor use; (3) The adhesion is limited. The adhesion on some surfaces (such as glossy plastic) is not as good as oil-based ink; (4) The drying speed is affected by the environment. Although the drying speed of water-based ink is relatively fast, the drying speed may slow down in a humid environment.

[0004] The main difference between water-based ink and oil-based ink is the difference in solvents. Oil-based ink uses organic solvents (toluene, xylene, industrial alcohol, etc.) as solvents. The solvents used in water-based inks are water and ethanol excluded from the VOC list, which can greatly reduce VOC emissions. However, the existing water-based inks have dull luster, poor fullness, poor weather resistance, flexibility and impact resistance, and are not suitable for high-speed printing. In addition, in the existing technology, the viscosity of water-based inks is difficult to control, and the viscosity change law is complex. In addition to conventional factors, it is also easily affected by pH value, a small amount of volatile components and certain additives; viscosity refers to the consistency of water-based ink, which is an indicator of the flow of water-based ink; too high viscosity causes poor fluidity and slow drying; low viscosity water-based ink has good fluidity, fast drying, thin ink layer, and less ink consumption, but if the viscosity of water-based ink is too low, the color powder content requirement is high. In the printing process, too low viscosity will cause light color; since the viscosity directly affects the transferability of ink and the quality of printed products, it is very important to control the viscosity of ink.

[0005] Chinese patent CN108659612A discloses a water-based ink, which uses styrene-modified polyacrylate to prepare an ink with excellent adhesion and stability. Chinese patent CN107286303A discloses a method for preparing an acrylic acid-modified polyurethane ink, which solves the adhesion problem of general water-based polyurethane ink on plastic substrates. However, the above patents introduce organic solvents (such as ammonia, ethanol, acetone, etc.) in the process of preparing the resin to reduce the viscosity of the ink and overcome the defects of the matrix resin being easy to agglomerate and slow film formation. The introduction of organic solvents will inevitably cause environmental pollution, and it is impossible to prepare a truly pure water-based ink. Therefore, providing a pure water-based ink that does not contain organic solvents and can be printed on a film is a technical problem that the prior art urgently needs to solve. Summary of the invention

[0006] The purpose of the present invention is to provide a pure water-based ink for a film, a preparation method thereof, and an application in gravure printing and flexographic printing. The pure water-based ink for a film provided by the present invention does not contain an organic solvent, can be printed on a film, and is suitable for gravure printing and flexographic printing.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The invention provides a pure water-based ink for a film, which is prepared by comprising the following raw materials, measured by weight: 22 to 55 parts of acrylic acid water-soluble resin, 10 to 20 parts of pigment, 8 to 14 parts of filler, 1 to 3 parts of dispersant, 0.08 to 0.24 parts of defoamer, 2 to 6 parts of acrylic acid coupling agent, 1 to 3 parts of surfactant and 10 to 35 parts of water.

[0009] Preferably, the preparation method includes the following raw materials, calculated by weight: 25 to 50 parts of acrylic water-soluble resin, 12 to 18 parts of pigment, 10 to 13 parts of filler, 1.5 to 2.5 parts of dispersant, 0.10 to 0.22 parts of defoamer, 3 to 5 parts of acrylic coupling agent, 1.5 to 2.5 parts of surfactant, and 12 to 32 parts of water.

[0010] Preferably, the acrylic water-soluble resin is prepared from the following raw materials, calculated by weight: 20 to 35 parts of isobornyl methacrylate, 10 to 25 parts of n-butyl methacrylate, 10 to 15 parts of isooctyl acrylate, 5 to 10 parts of acrylic acid, 4 to 7 parts of p-isobutyl styrene, and 0.2 to 0.4 parts of initiator.

[0011] Preferably, the initiator is azobisisobutyronitrile.

[0012] Preferably, the preparation method of the acrylic acid water-soluble resin comprises: mixing isooctyl acrylate, acrylic acid, para-isobutyl styrene and an initiator, heating to 70-90° C., adding isobornyl methacrylate and n-butyl methacrylate under stirring conditions, heating to 130-150° C., and conducting a polymerization reaction for 2-4 hours to obtain an acrylic acid water-soluble resin.

[0013] Preferably, the defoaming agent is a non-silicone defoaming agent; the surfactant is sodium lauryl sulfate; and the dispersant is ethylene glycol stearate.

[0014] Preferably, the acrylic coupling agent is one or more of KH-450 water-based silane coupling agent, KH560 silane coupling agent, 3-trimethoxysilane propyl acrylate, and acryloxy triisopropyl silane.

[0015] The present invention also provides a method for preparing the pure water-based ink for thin film described in the above technical solution, comprising the following steps:

[0016] After mixing water, pigment and filler, a mixture is obtained by first stirring.

[0017] A surfactant and a dispersant are added to the mixture, and the mixture is stirred for the second time. Then, an acrylic coupling agent is added, and the mixture is ground and then a defoaming agent is added and mixed uniformly to obtain a pure water-based ink for a film.

[0018] Preferably, the grinding treatment time is 2 to 4 hours, the grinding treatment temperature is 25 to 40° C., and the grinding treatment speed is 1000 to 1500 r / min.

[0019] The present invention also provides an application of pure water-based ink for thin films in gravure printing and flexographic printing. The pure water-based ink for thin films is the pure water-based ink for thin films described in the above technical solution or the pure water-based ink for thin films prepared by the preparation method.

[0020] The present invention provides a pure water-based ink for a film, which uses a certain amount of acrylic acid water-soluble resin as a connecting material, plays a role in dispersing and stabilizing pigments, improving printing quality, and improving fluidity and wettability in the pure water-based ink, and is environmentally friendly; a certain amount of pigment and filler are added to impart color; a dispersant is used to maintain the stability of the pigment and the filler, prevent the two from agglomerating and precipitating, thereby maintaining the quality and performance of the pure water-based ink, and increasing the storage stability of the pure water-based ink; at the same time, the dispersant can adjust the viscosity, improve the fluidity of the pure water-based ink, and make it easier to be evenly coated on a substrate; the defoaming agent can inhibit the formation of foam, avoid the adverse effects of bubbles on the performance of the pure water-based ink, significantly improve the coating performance of the pure water-based ink, and improve the wettability of the pure water-based ink. The invention discloses a pure water-based ink having a good surface tension and fluidity, and is easier to coat on a substrate, and can form a uniform coating, reduce printing defects, and improve printing quality and efficiency; acrylic coupling agents can improve the compatibility between the components in pure water-based ink, enhance the adhesion between pure water-based ink and substrates, improve dispersibility, and can more effectively disperse pigments or other solid particles in pure water-based ink, reduce particle agglomeration and precipitation, improve the uniformity and stability of pure water-based ink, and enhance the weather resistance and water resistance of pure water-based ink; surfactants can reduce the surface tension of pure water-based ink, enhance the stability of pure water-based ink, prevent the agglomeration and precipitation of pigments or other solid particles, and finally obtain a pure water-based ink that does not contain organic solvents and can be printed on a film and is suitable for gravure printing and flexographic printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a comparison chart of the surface drying time after printing with pure water-based ink for the films prepared in Examples 1 to 5 of the present application and pure water-based ink for the films prepared in Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0022] The invention provides a pure water-based ink for a film, which is prepared by comprising the following raw materials, measured by weight: 22 to 55 parts of acrylic acid water-soluble resin, 10 to 20 parts of pigment, 8 to 14 parts of filler, 1 to 3 parts of dispersant, 0.08 to 0.24 parts of defoamer, 2 to 6 parts of acrylic acid coupling agent, 1 to 3 parts of surfactant and 10 to 35 parts of water.

[0023] In the present invention, unless otherwise specified, the raw materials used are conventional commercial products in the art.

[0024] In the present invention, the pure water-based ink for the film is prepared by including the following raw materials, calculated by weight: 25 to 50 parts of acrylic acid water-soluble resin, 12 to 18 parts of pigment, 10 to 13 parts of filler, 1.5 to 2.5 parts of dispersant, 0.10 to 0.22 parts of defoaming agent, 3 to 5 parts of acrylic coupling agent, 1.5 to 2.5 parts of surfactant, and 12 to 32 parts of water.

[0025] In the present invention, the acrylic acid water-soluble resin is preferably prepared by the following raw materials, calculated by weight: 20 to 35 parts of isobornyl methacrylate, 10 to 25 parts of n-butyl methacrylate, 10 to 15 parts of isooctyl acrylate, 5 to 10 parts of acrylic acid, 4 to 7 parts of p-isobutyl styrene, and 0.2 to 0.4 parts of initiator. The present invention controls the type and amount of raw materials used to prepare the acrylic acid water-soluble resin within the above range to improve the promotion of complete monomer reaction, reduce the amount of residual monomers, and at the same time increase the crosslinking density and adjust the glass transition temperature of the prepared acrylic acid water-soluble resin, thereby improving the film-forming performance, water resistance and chemical resistance of the prepared acrylic acid water-soluble resin, and improving the surface drying rate of the pure water-based ink coating for the subsequent thin film.

[0026] In the present invention, the initiator is preferably azobisisobutyronitrile.

[0027] In the present invention, the method for preparing the acrylic acid water-soluble resin preferably comprises: mixing isooctyl acrylate, acrylic acid, p-isobutyl styrene and an initiator, heating to 70-90° C., adding isobornyl methacrylate and n-butyl methacrylate under stirring conditions, heating to 130-150° C., and performing a polymerization reaction for 2-4 hours to obtain an acrylic acid water-soluble resin. The present invention adopts the above method to prepare an acrylic acid water-soluble resin, promotes the full reaction of each component, and obtains an acrylic acid water-soluble resin with low residual monomer content and high film-forming performance.

[0028] In the present invention, the defoamer is preferably a non-silicone defoamer, more preferably BYK-052N defoamer. The present invention utilizes a defoamer to suppress foam, avoid the presence of bubbles causing pores and unevenness in the pure water-based ink coating, and seriously affect the coating performance and printing quality; the defoamer can also significantly improve the coating performance of the pure water-based ink, ensure the smoothness and uniformity of the ink coating, reduce the number of pores on the coating surface, and thus improve the quality of the coating; the defoamer can reduce the surface tension of the coating, thereby improving the wettability and fluidity of the coating, making it easier for the pure water-based ink to be coated on the substrate, and can form a uniform film, reduce printing defects, improve printing quality and efficiency, and optimize the printing effect; the defoamer can also help stabilize the emulsified state of the pure water-based ink, prevent the separation of oil and water in the emulsion, thereby improving the stability and shelf life of the ink, and helping to ensure that the ink maintains excellent performance for a long time.

[0029] In the present invention, the surfactant is preferably sodium dodecyl sulfate. The present invention utilizes surfactants to significantly reduce the surface tension of pure water-based ink, making it easier to spread and penetrate on the substrate, improving the wettability and fluidity of pure water-based ink, thereby improving the quality and efficiency of printed products; surfactants can enhance the stability of pure water-based ink, prevent the agglomeration and precipitation of pigments or other solid particles; surfactants also have dispersing and stabilizing effects, which can ensure that pure water-based ink maintains a uniform dispersion state during long-term storage and use, thereby extending its service life; surfactants can also optimize the printing performance of pure water-based ink by adjusting its viscosity; surfactants can balance the viscosity of pure water-based ink, making it more suitable for different printing methods and substrate types; surfactants can also improve the adhesion between pure water-based ink and substrates, and enhance the adhesion between printed products and substrates, thereby improving the durability and wear resistance of printed products.

[0030] In the present invention, the pigment is preferably one or more of lithopone, carbon black, titanium dioxide, ferric oxide, and ferric hydroxide. In the present invention, the filler is preferably one or more of barium sulfate, nano calcium carbonate, kaolin, and talc.

[0031] In the present invention, the dispersant is preferably ethylene glycol stearate. The present invention utilizes the dispersant to maintain the stability of the pigment and the filler, prevent the two from agglomerating and precipitating, thereby maintaining the quality and performance of the pure water-based ink, increasing the storage stability of the pure water-based ink, and at the same time adjusting the viscosity, improving the fluidity of the pure water-based ink, making it easier to be evenly coated on the substrate.

[0032] In the present invention, the acrylic coupling agent is preferably one or more of KH-450 water-based silane coupling agent, KH560 silane coupling agent, 3-trimethoxysilane propyl acrylate, and acryloxy triisopropyl silane. The present invention utilizes the groups in the acrylic coupling agent that can react with the functional groups on the molecular chain of the water-based acrylic resin to connect different polymer segments through chemical bonds or physical interactions, thereby improving the compatibility between the components in the pure water-based ink. This improvement in compatibility helps to ensure the stability of the pure water-based ink during preparation and use, and prevents separation or precipitation between the components; the acrylic coupling agent can improve the interfacial bonding force between the pure water-based ink and the substrate, thereby enhancing the adhesion. Improve the quality and durability of printed materials, so that pure water-based ink can adhere more closely to the surface of the substrate, reducing the possibility of falling off or peeling; acrylic coupling agent also has a certain dispersing effect, which can disperse pigments or other solid particles in pure water-based ink more effectively, helping to reduce particle agglomeration and precipitation, and improve the uniformity and stability of pure water-based ink. The improvement in dispersibility helps to ensure the uniformity and consistency of the color of printed materials; by introducing acrylic coupling agent, the density and cross-linking degree of pure water-based ink coating can be enhanced, thereby reducing the penetration and erosion of moisture and other harmful substances, and the weather resistance and water resistance of pure water-based ink can be improved, which helps to extend the service life of printed materials and maintain their good appearance.

[0033] The present invention also provides a method for preparing the pure water-based ink for thin film described in the above technical solution, comprising the following steps:

[0034] After mixing water, pigment and filler, a mixture is obtained by first stirring.

[0035] A surfactant and a dispersant are added to the mixture, and the mixture is stirred for the second time. Then, an acrylic coupling agent is added, and the mixture is ground and then a defoaming agent is added and mixed uniformly to obtain a pure water-based ink for a film.

[0036] The present invention has no special limitation on the first stirring treatment and the second stirring treatment, and any technical solution known in the art may be used.

[0037] In the present invention, the grinding time is preferably 2 to 4 hours; the grinding temperature is preferably 25 to 40°C, and the grinding speed is preferably 1000 to 1500 r / min. The present invention significantly refines the pigment and filler particles through grinding, uniformly disperses the pigment particles in the resin, ensures that the pigment particles are fine and evenly distributed, and the fine pigment particles can better penetrate into the surface of the substrate, which helps to improve the printing effect and color saturation of pure water-based ink, improve the adhesion and printing clarity of pure water-based ink, and improve the surface drying rate of the coating. At the same time, the refined pigment particles can also reduce the clogging phenomenon in the printing process and improve the printing efficiency; through grinding, the viscosity, glossiness, tinting power and other key properties of pure water-based ink can be adjusted. At the same time, grinding can also improve the drying speed and friction resistance of the ink, thereby extending the service life of the printed product; during the grinding process, the pigment, resin and additives can be more fully mixed and reacted to form a stable colloidal system, which can resist the interference of external factors, such as changes in temperature and humidity, thereby maintaining the stability of the performance of pure water-based ink.

[0038] The present invention also provides an application of pure water-based ink for thin films in gravure printing and flexographic printing. The pure water-based ink for thin films is the pure water-based ink for thin films described in the above technical solution or the pure water-based ink for thin films prepared by the preparation method.

[0039] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] A pure water-based ink for film is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 3 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 22 parts of water;

[0042] The acrylic acid water-soluble resin is prepared from the following raw materials, by weight: 25 parts of isobornyl methacrylate, 13 parts of n-butyl methacrylate, 12 parts of isooctyl acrylate, 8 parts of acrylic acid, 6 parts of p-isobutyl styrene, and 0.3 parts of initiator.

[0043] The preparation method of the acrylic acid water-soluble resin comprises the following steps: uniformly mixing isooctyl acrylate, acrylic acid, p-isobutyl styrene and an initiator, heating to 75° C., adding isobornyl methacrylate and n-butyl methacrylate under stirring conditions, heating to 140° C., and carrying out polymerization reaction under stirring conditions for 3 hours to obtain the acrylic acid water-soluble resin;

[0044] The method for preparing the pure water-based ink for the film comprises the following steps:

[0045] After mixing water, pigment and filler, stir for the first time at room temperature for 20 minutes to obtain a mixture;

[0046] Add a surfactant and a dispersant to the mixture, stir for a second time at room temperature for 40 minutes, add an acrylic coupling agent, grind for 2.5 hours at 40° C. and a rotation speed of 1200 r / min, add a defoamer and mix well to obtain a pure water-based ink for a film.

[0047] Example 2

[0048] A pure water-based ink for film is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 4 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 22 parts of water;

[0049] According to the method of Example 1, an acrylic water-soluble resin and a pure aqueous ink for a film were prepared.

[0050] Example 3

[0051] A pure water-based ink for film is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 5 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 22 parts of water;

[0052] According to the method of Example 1, an acrylic water-soluble resin and a pure aqueous ink for a film were prepared.

[0053] Example 4

[0054] A pure water-based ink for film is prepared from the following raw materials, measured by weight: 40 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 4 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 28 parts of water;

[0055] According to the method of Example 1, an acrylic water-soluble resin and a pure aqueous ink for a film were prepared.

[0056] Example 5

[0057] A pure water-based ink for film is prepared from the following raw materials, measured by weight: 45 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 4 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 32 parts of water;

[0058] According to the method of Example 1, an acrylic water-soluble resin and a pure aqueous ink for a film were prepared.

[0059] Comparative Example 1

[0060] A pure water-based ink is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of nano calcium carbonate filler, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 1.5 parts of surfactant sodium lauryl sulfate, and 22 parts of water;

[0061] Acrylic water-soluble resin and pure water-based ink were prepared according to the method of Example 1.

[0062] Comparative Example 2

[0063] A pure water-based ink is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 1.5 parts of dispersant ethylene glycol stearate, 0.18 parts of BYK-052N defoamer, 3 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, and 22 parts of water;

[0064] According to the method of Example 1, an acrylic acid water-soluble resin and a pure aqueous ink were prepared.

[0065] Comparative Example 3

[0066] A pure water-based ink is prepared from the following raw materials, measured by weight: 35 parts of acrylic acid water-soluble resin, 12 parts of ferric oxide pigment, 10 parts of filler nano calcium carbonate, 0.18 parts of BYK-052N defoamer, 3 parts of acrylic coupling agent 3-trimethoxysilane propyl acrylate, 1.5 parts of surfactant sodium dodecyl sulfate, and 22 parts of water;

[0067] According to the method of Example 1, an acrylic acid water-soluble resin and a pure aqueous ink were prepared.

[0068] The viscosity of the pure water-based ink for the thin film prepared in Examples 1 to 5 of the present application and the pure water-based ink prepared in Comparative Examples 1 to 3 is set to 13±2s, the viscosity test instrument is: RIGOSHA 4# cup (25°C), the yield value unit is dyn / cm 2 After printing on plastic packaging film, the results are compared as shown in Table 1 and Figure 1 shown.

[0069] Figure 1 This is a comparison chart of the surface drying time after printing with pure water-based ink for the films prepared in Examples 1 to 5 of the present application and pure water-based ink for the films prepared in Comparative Examples 1 to 3.

[0070] Table 1 Printing performance of pure water-based ink for thin films prepared in Examples 1 to 5 and pure water-based ink for thin films prepared in Comparative Examples 1 to 3

[0071]

[0072] In summary, compared with the comparative example, the films prepared in Examples 1 to 5 of the present application are printed with pure water-based ink with deep color, small thixotropy, moderate yield value, bright color and short surface drying time.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pure water-based ink for film, characterized in that: The preparation method comprises the following raw materials, calculated by weight: 22 to 55 parts of acrylic acid water-soluble resin, 10 to 20 parts of pigment, 8 to 14 parts of filler, 1 to 3 parts of dispersant, 0.08 to 0.24 parts of defoamer, 2 to 6 parts of acrylic acid coupling agent, 1 to 3 parts of surfactant and 10 to 35 parts of water.

2. The pure water-based ink for thin film according to claim 1, characterized in that: The preparation method comprises the following raw materials, calculated by weight: 25 to 50 parts of acrylic acid water-soluble resin, 12 to 18 parts of pigment, 10 to 13 parts of filler, 1.5 to 2.5 parts of dispersant, 0.10 to 0.22 parts of defoamer, 3 to 5 parts of acrylic acid coupling agent, 1.5 to 2.5 parts of surfactant and 12 to 32 parts of water.

3. The pure water-based ink for thin film according to claim 1, characterized in that: The acrylic water-soluble resin is prepared from the following raw materials, calculated by weight: 20 to 35 parts of isobornyl methacrylate, 10 to 25 parts of n-butyl methacrylate, 10 to 15 parts of isooctyl acrylate, 5 to 10 parts of acrylic acid, 4 to 7 parts of p-isobutyl styrene, and 0.2 to 0.4 parts of initiator.

4. The pure water-based ink for thin film according to claim 3, characterized in that: The initiator is azobisisobutyronitrile.

5. The pure water-based ink for thin film according to claim 3, characterized in that: The preparation method of the acrylic acid water-soluble resin comprises: mixing isooctyl acrylate, acrylic acid, p-isobutyl styrene and an initiator, heating to 70-90° C., adding isobornyl methacrylate and n-butyl methacrylate under stirring conditions, heating to 130-150° C., and performing polymerization reaction for 2-4 hours to obtain the acrylic acid water-soluble resin.

6. The pure water-based ink for thin film according to claim 1, characterized in that: The defoaming agent is a non-silicone defoaming agent; the surfactant is sodium lauryl sulfate; and the dispersant is ethylene glycol stearate.

7. The pure water-based ink for thin film according to claim 1, characterized in that: The acrylic coupling agent is one or more of KH-450 water-based silane coupling agent, KH560 silane coupling agent, 3-trimethoxysilane propyl acrylate, and acryloxy triisopropyl silane.

8. The method for preparing the pure water-based ink for thin film according to any one of claims 1 to 7, characterized in that: The following steps are involved: After mixing water, pigment and filler, a mixture is obtained by first stirring. A surfactant and a dispersant are added to the mixture, and the mixture is stirred for the second time. Then, an acrylic coupling agent is added, and the mixture is ground and then a defoaming agent is added and mixed uniformly to obtain a pure water-based ink for a film.

9. The method for preparing the pure water-based ink for thin film according to claim 8, characterized in that: The grinding time is 2 to 4 hours, the grinding temperature is 25 to 40° C., and the grinding speed is 1000 to 1500 r / min.

10. Application of pure water-based ink for film in gravure printing and flexographic printing, characterized in that: The pure water-based ink for thin film is the pure water-based ink for thin film according to any one of claims 1 to 7 or the pure water-based ink for thin film prepared by the preparation method according to claim 8 / 9.

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