High-blackness water-based color ink and preparation method thereof

Abstract

The invention relates to high-blackness water-based color ink and a preparation method thereof. The high-blackness water-based color ink comprises the following raw materials in parts by mass: 20-30 parts of water-based acrylic resin; 10 to 20 parts of a polyurethane emulsion; 20 to 25 parts of carbon black; 1-10 parts of an anti-wear agent; 20 to 40 parts of a solvent; 2.5 to 3 parts of a surfactant; 1-3 parts of an auxiliary agent; wherein the water-based acrylic resin is a copolymer of butyl acrylate and methyl methacrylate, the anti-wear agent is a wax emulsion, the solvent is a mixed solution of water and ethanol, the surfactant is octylphenol polyoxyethylene ether, the auxiliaries comprise a defoaming agent and a flatting agent, the defoaming agent is emulsified silicone oil, and the flatting agent is butyl acrylate. The flatting agent is a mixed solution of isopropanol and propylene glycol. Compared with the prior art, the wear-resistant printing ink has excellent wear resistance and adhesion fastness and stable printing performance, so that printed images and texts are clear, the color is full, and the printing effect is good.

Description

Technical Field

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

[0002] Water-based ink is abbreviated as water ink. The main difference between water-based ink and oil-based ink lies in the different solvents. Water-based ink uses water as the solvent, with a very low VOC (volatile organic compound) content and little environmental pollution; oil-based ink uses organic solvents as the solvent. In the flexible packaging industry, since oil-based ink mainly uses volatile drying, the lower the boiling point of the solvent, the easier it is to volatilize and release toxic gases to pollute the environment, and there are also residual toxic substances on its surface after printing. While the solvents used in water-based ink are water and ethanol excluded from the VOC list, which can greatly reduce the VOC emissions.

[0003] Pigments endow the ink with color characteristics and meet the requirements of printing for colors. Generally, organic pigments and inorganic pigments can be used in water-based ink. Since most of the resins in water-based ink are alkali-soluble, when selecting pigments, pigments resistant to alkalinity must be used. However, the distribution density of pigments in water ink is much larger than that in oil-based ink, and the surface tension and polarity of water are very different from those of organic solvents, making it difficult to disperse pigments, which directly affects the stability, viscosity and pH value of water ink. Especially for water-based black ink, due to its own characteristics, there will be tailing and insufficient blackness during intaglio printing. In addition, during intaglio printing, water-based black ink often shows phenomena such as color flocs and color spots due to uneven mixing of color pastes, which further affects the wear resistance and adhesion fastness of water-based black ink. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-blackness water-based color ink and a preparation method thereof to overcome the problems of tailing, poor wear resistance and adhesion fastness of existing water-based black ink during printing.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a high-blackness water-based color ink, which comprises the following raw materials in parts by mass:

[0007]

[0008]

[0009] Among them, the water-based acrylic resin is a copolymer of butyl acrylate and methyl methacrylate, the anti-wear agent is a wax emulsion, the solvent is a mixture of water and ethanol, the surfactant is octylphenol polyoxyethylene ether, and the auxiliary agents include defoamers and leveling agents.

[0010] In some specific embodiments, the mass ratio of methyl methacrylate to butyl acrylate in the aqueous acrylic resin is 1:0.5 to 1:20.

[0011] In some specific embodiments, the defoaming agent is emulsified silicone oil; the leveling agent is a mixture of isopropanol and propylene glycol, and the mass ratio of isopropanol to propylene glycol is 1:1 to 1.5.

[0012] In some specific embodiments, the mass ratio of water to ethanol in the solvent is 4:1.

[0013] The second technical solution of the present invention is to provide a preparation method of a high-blackness aqueous ink as described in one of the above technical solutions, including the following steps:

[0014] S1. Stir and mix carbon black with a part of the solvent once, and then sequentially add a part of the aqueous acrylic resin, polyurethane emulsion, anti-wear agent, surfactant, and auxiliary agent for secondary stirring and mixing. After primary sanding, an aqueous ink paste is obtained;

[0015] S2. Stir and mix the aqueous ink paste obtained in step S1 with the remaining solvent and aqueous acrylic resin three times. After secondary sanding, a high-blackness aqueous ink is obtained.

[0016] In some specific embodiments, in step S1, the rotation speed of the primary stirring is 700 - 1200 revolutions per minute, and the primary stirring time is 20 - 30 min.

[0017] In some specific embodiments, in step S1, the rotation speed of the secondary stirring is 500 - 800 revolutions per minute, and the secondary stirring time is 25 - 30 minutes.

[0018] In some specific embodiments, in step S1, the process of primary sanding is: first sand at a flow rate of 50 Kg / hour, and then sand at a flow rate of 100 Kg / hour until the fineness is lower than 5 μm.

[0019] In some specific embodiments, in step S2, the rotation speed of the tertiary stirring is 800 - 1000 revolutions per minute, the temperature of the tertiary stirring is 20 - 30 °C, and the tertiary stirring time is 30 min.

[0020] In some specific embodiments, in step S2, the process of secondary sanding is: sand at a flow rate of 100 Kg / hour until the fineness is lower than 15 μm.

[0021] In the present invention, waterborne acrylic resin and polyurethane emulsion are selected as the waterborne binder. The waterborne acrylic resin has excellent weather resistance, adjustable properties, no release of organic solvents, environmental protection and other advantages. After the waterborne acrylic resin and polyurethane emulsion are mixed according to the ratio of the present invention, a binder with a high solid content, a hard and wear-resistant paint film, good mechanical properties, excellent chemical corrosion resistance, good oil and solvent resistance is obtained.

[0022] In addition, the wax emulsion is mainly used to further increase the fastness and scratch resistance of the high-blackness water-based ink. The emulsified silicone oil can play a defoaming role. Isopropyl alcohol and propylene glycol can effectively improve the leveling of the high-blackness water-based ink. Octylphenol polyoxyethylene ether can endow the high-blackness water-based ink with good color spreading and wear resistance, ensuring uniform distribution of the ink and no trailing or color spots on the printed matter.

[0023] By limiting the ratio of each component, the present invention effectively controls the viscosity and properties of the high-blackness water-based ink. Especially for the additives, if the ratio is too high, it is very likely that the structure of each component of the produced high-blackness water-based ink will be damaged and it cannot be used normally. At the same time, the present invention stipulates the feeding order. If the feeding order is disordered, the components of the high-blackness water-based ink cannot be fully mixed, affecting the quality.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) By selecting waterborne acrylic resin and polyurethane emulsion as the waterborne binder and mixing them with carbon black, solvent and additives in proportion, the present invention does not use toxic solvents, reducing the physical harm to production workers and users.

[0026] (2) The high-blackness water-based ink prepared by the present invention has excellent wear resistance, adhesion fastness and stable printing performance, making the printed graphics and texts clear, the colors full and the printing effect good. Detailed Embodiment

[0027] The present invention will be described in detail below with reference to specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and the detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0028] In the following examples and comparative examples, unless otherwise specified, the raw materials or treatment techniques are all conventional commercially available raw material products or conventional treatment techniques in the art.

[0029] The waterborne acrylic resin is a copolymer of butyl acrylate and methyl methacrylate, and is prepared with reference to Example 1 of CN104945556A, with "butyl acrylate" and "styrene" replaced equally.

[0030] Example 1:

[0031] This embodiment provides a high-blackness water-based color ink, which comprises raw materials in the following parts by mass: 20 parts of water-based acrylic resin, 15 parts of polyurethane emulsion, 25 parts of carbon black, 4.5 parts of anti-wear agent wax emulsion, 30 parts of solvent (the mass ratio of deionized water to ethanol is 4 / 1), 3 parts of surfactant octylphenol polyoxyethylene ether, 0.5 part of defoaming agent emulsified silicone oil, and 1 part of leveling agent mixture of isopropanol and propylene glycol (volume ratio is 1:2).

[0032] The specific preparation process is as follows:

[0033] Put 25 parts of carbon black into 20 parts of the solvent under high-speed stirring. First, stir at a speed of 700 revolutions per minute for 60 minutes. Further, then stir at about 1100 revolutions per minute for about 25 minutes until completely and evenly mixed, and then put in 10 parts of water-based acrylic resin, 10 parts of polyurethane emulsion, 4.5 parts of anti-wear agent, 3 parts of surfactant, and 1.5 parts of auxiliary agent. The stirring speed is about 600 revolutions per minute, and the stirring time is about 27 minutes. Grind with a flow rate of 50 Kg / hour, and then grind with a flow rate of 100 Kg / hour to make its fineness less than 5 μm.

[0034] Stir and disperse the ground color paste evenly with the remaining 10 parts of water-based acrylic resin, 5 parts of polyurethane emulsion and 10 parts of solvent. The stirring speed is 800 revolutions per minute, the temperature is about 25 °C, and the stirring time is 30 min. Put the product into a sand mill and grind with a flow rate of 100 Kg / hour to make its fineness less than 15 μm, then the target product is obtained.

[0035] The high-blackness water-based color ink produced in this example has good printing adaptability, and there are no problems such as trailing, color spots, and color flocs during the printing process. In addition, its wear resistance and adhesion fastness are also very excellent.

[0036] Taking 80 g coated paper as an example, coat the high-blackness water-based color ink prepared in this embodiment on the coated paper. The high-blackness water-based color ink has no peeling and color mixing phenomena within the range of 0 °C - 180 °C. Under a pressure of 4 pounds, the wear resistance is more than 200 times, and the wear resistance performance is excellent.

[0037] Taking PET substrate as an example, coat the high-blackness water-based color ink prepared in this embodiment on the PET substrate. The high-concentration water-based black ink has excellent adhesion fastness, no peeling phenomenon under the pull of 3M tape, uniform color concentration, and good printing performance.

[0038] Comparative Example 1

[0039] Compared with Example 1, most of them are the same. The difference is that the polyurethane emulsion is replaced with an equal number of parts of water-based acrylic resin.

[0040] The water-based color ink provided in this comparative example includes raw materials in the following parts by mass: 35 parts of water-based acrylic resin, 25 parts of carbon black, 4.5 parts of anti-wear agent wax emulsion, 30 parts of solvent (the mass ratio of deionized water to ethanol is 4 / 1), 3 parts of surfactant octylphenol polyoxyethylene ether, 0.5 part of defoaming agent emulsified silicone oil, and 1 part of leveling agent mixture of isopropanol and propylene glycol (volume ratio is 1:2).

[0041] The specific preparation process is as follows:

[0042] Put 25 parts of carbon black into 20 parts of the solvent under high-speed stirring. First, stir at a speed of 700 revolutions per minute for 60 minutes. Further, then stir at about 1100 revolutions per minute for about 25 minutes until completely mixed evenly. Then add 10 parts of water-based acrylic resin, 4.5 parts of anti-wear agent, 3 parts of surfactant, and 1.5 parts of other additives. The stirring speed is about 600 revolutions per minute, and the stirring time is about 27 minutes. Grind with a flow rate of 50 Kg / hour, and then grind with a flow rate of 100 Kg / hour to ensure that its fineness is less than 5 μm.

[0043] Stir and disperse the ground color paste evenly with the remaining 25 parts of water-based acrylic resin and 10 parts of solvent. The stirring speed is 800 revolutions per minute, the temperature is about 25°C, and the stirring time is 30 min. Put the product into a sand mill and grind it with a flow rate of 100 Kg / hour to make its fineness less than 15 μm, and then the target product is obtained.

[0044] The water-based color ink produced in this comparative example did not have problems such as trailing, color dots, and color flocs during the printing process, but its wear resistance and adhesion fastness were both mediocre.

[0045] Taking 80g coated paper as an example, coat the water-based color ink prepared in this comparative example on the coated paper. The water-based color ink has no peeling or color adjustment phenomena within the range of 0°C - 180°C. Under a pressure of 4 pounds, the wear resistance does not exceed 100 times, and it cannot be used on products with higher requirements.

[0046] Taking a PET substrate as an example, coat the water-based color ink prepared in this comparative example on the PET substrate. The color concentration of the water-based color ink is relatively uniform, but there are slightly problems with the adhesion fastness, and there is slight peeling under the pull of a 3M tape.

[0047] Mainly because there are no polar groups such as urethane, allophanate, ester bond, and ether bond on the polyurethane emulsion to form hydrogen bonds with the polar groups on the surfaces of various polar substrates such as PET and PA plastics, the prepared water-based color ink has poor wear resistance and adhesion fastness.

[0048] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention as disclosed should be within the protection scope of the present invention.

Claims

1. A high-blackness water-based ink colorant, characterized in that, it comprises raw materials in the following parts by mass: Among them, the water-based acrylic resin is a copolymer of butyl acrylate and methyl methacrylate, the anti-wear agent is a wax emulsion, the solvent is a mixture of water and ethanol, the surfactant is octylphenol polyoxyethylene ether, and the additives include a defoaming agent and a leveling agent.

2. The high-blackness water-based ink colorant according to claim 1, characterized in that, the mass ratio of butyl acrylate to methyl methacrylate in the water-based acrylic resin is 1:0.5 to 1:

20.

3. The high-blackness water-based ink colorant according to claim 1, characterized in that, the defoaming agent is emulsified silicone oil; the leveling agent is a mixture of isopropanol and propylene glycol, and the mass ratio of isopropanol to propylene glycol is 1:1 to 1.

5.

4. The high-blackness water-based ink colorant according to claim 1, characterized in that, the mass ratio of water to ethanol in the solvent is 4:

1.

5. A preparation method of the high-blackness water-based ink colorant according to any one of claims 1-4, characterized in that, it comprises the following steps: S1. First, carbon black is stirred and mixed with a part of the solvent, and then a part of the water-based acrylic resin, polyurethane emulsion, anti-wear agent, surfactant, and additives are successively added for secondary stirring and mixing, and a water-based ink paste is obtained after primary sanding; S2. The water-based ink paste obtained in step S1 is stirred and mixed with the remaining solvent and water-based acrylic resin for the third time, and a high-blackness water-based ink colorant is obtained after secondary sanding.

6. The high-blackness water-based ink colorant according to claim 5, characterized in that, in step S1, the rotation speed of the primary stirring is 700-1200 revolutions per minute, and the primary stirring time is 20-30 min.

7. The high-blackness water-based ink colorant according to claim 5, characterized in that, in step S1, the rotation speed of the secondary stirring is 500-800 revolutions per minute, and the secondary stirring time is 25-30 minutes.

8. The high-blackness water-based ink colorant according to claim 5, characterized in that, in step S1, the process of primary sanding is: first sand at a flow rate of 50 Kg / hour, and then sand at a flow rate of 100 Kg / hour, so that its fineness is lower than 5 μm.

9. The high-blackness water-based ink colorant according to claim 5, characterized in that, in step S2, the rotation speed of the third stirring is 800-1000 revolutions per minute, the temperature of the third stirring is 20-30 °C, and the third stirring time is 30 min.

10. The high-blackness water-based ink colorant according to claim 5, characterized in that, in step S2, the process of secondary sanding is: sand at a flow rate of 100 Kg / hour, so that its fineness is lower than 15 μm.

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