Recoating water-based propylene ink and preparation method thereof

Abstract

The invention discloses recoatable water-based propylene ink and a preparation method thereof. By preferably selecting the resin emulsion and the modified hydrophobic agent, a coating film is endowed with high adhesive force and flexibility, the balance of waterproofness and wettability of the propylene ink coating film is realized, and the problems of hue shift, interlayer adhesive force failure, coating integrity damage and the like in the recoating process of the traditional propylene ink are effectively solved; the performance of the ink in professional painting and industrial application is obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water-based ink, in particular to a water-based acrylic ink with recoatability and a preparation method thereof. BACKGROUND

[0002] To meet the needs of high coverage, fast drying and material universality for art creation, acrylic marker ink emerges as the times require. In recent years, with the upgrading of market demand and the guidance of standardization, environmental protection and non-toxicity and functional compounding have become the main development trend in this field. For example, Suzhou Eagle discloses a water-based acrylic marker ink in CN201911416978.5, which completely abandons organic solvents and uses amphiphilic polymers to build a stable system; Zhejiang Best discloses an acrylic marker ink in CN202410283569.70, which innovatively introduces a double filler network (white carbon black / montmorillonite) to improve the suspension stability. However, these inventions still have not broken through the significant technical bottlenecks of traditional acrylic ink in recoatability, adhesion, weather resistance and other aspects, especially the color phase deviation, interlayer adhesion failure and coating integrity damage problems in the recoating process, which seriously limit the performance of acrylic ink in professional painting and industrial applications.

[0003] Recoatability requires that the coating film has certain water resistance to prevent pigments, additives, film-forming resins and other components in the bottom coating film from being affected by the recoating ink, causing diffusion, migration and swelling, and thus causing problems such as color mixing, cracking and adhesion loss. Therefore, a small amount of additive needs to be added to the ink to improve the hydrophobicity of the coating film. The mechanism of the existing ink hydrophobic agent is mostly to reduce the surface tension of the coating film, making it difficult for water to wet, but this also affects the wetting of the recoating ink on the bottom coating film, thereby reducing the recoatability of the ink. Therefore, the inherent contradiction between coating hydrophobicity and wettability needs to be broken through by formula design.

[0004] Therefore, it is an urgent problem in the current technical field to develop a water-based acrylic ink that can balance the water resistance and wettability of the coating film and has excellent recoatability. SUMMARY

[0005] The purpose of the present application is to solve the defects of the prior art and to improve the recoatability of water-based acrylic ink. In view of the above technical bottlenecks, the present application aims to develop a water-based acrylic ink with recoatability and a preparation method thereof.

[0006] The ink of the present application gives the coating film high adhesion and flexibility by optimizing the resin emulsion and modified hydrophobic agent, while balancing the water resistance and wettability of the acrylic ink coating film, thereby giving the ink excellent recoatability.

[0007] The present application is mainly realized by the following technical solutions: The present application provides a recoatable water-based acrylic ink, comprising, by mass fraction: 5-40% colorant, 0-25% pigment paste, 20-40% film-forming resin emulsion, 1-5% modified hydrophobic agent, 1-4% dispersant, 2-6% humectant component, 0.2-0.5% preservative, 0.1-0.5% wetting agent, 0.1-0.5% pH regulator, and the rest being deionized water; The film-forming resin emulsion is one or more of an acrylic resin emulsion, a polyurethane resin emulsion, and an epoxy resin emulsion. The modified hydrophobic agent is one or more of a water-based silicone-acrylate copolymer, a nano-composite hydrophobic agent, and a modified polysiloxane copolymer.

[0008] Preferably, the recoatable water-based acrylic ink comprises, by mass fraction: 5-25% colorant, 0-25% pigment paste, 30-40% film-forming resin emulsion, 3-5% modified hydrophobic agent, 1-3% dispersant, 2-6% humectant component, 0.2-0.5% preservative, 0.1-0.5% wetting agent, 0.1-0.5% pH regulator, and the rest being deionized water. More preferably, the recoatable water-based acrylic ink comprises, by mass fraction: 5-25% colorant, 0-25% pigment paste, 30-40% film-forming resin emulsion, 3-5% modified hydrophobic agent, 1-3% dispersant, 2% humectant component, 0.2% preservative, 0.2% wetting agent, 0.2% pH regulator, and the rest being deionized water.

[0009] More preferably, the film-forming resin emulsion is an acrylic resin emulsion, and the modified hydrophobic agent is a water-based silicone-acrylate copolymer.

[0010] Preferably, in a specific embodiment of the present application, the colorant comprises one or more of titanium dioxide, zinc oxide, and lithopone, preferably titanium dioxide.

[0011] Preferably, in a specific embodiment of the present application, the pigment paste comprises one or more of red pigment paste, blue pigment paste, and green pigment paste.

[0012] Preferably, in a specific embodiment of the present application, the dispersant is a phosphate surfactant.

[0013] Preferably, in a specific embodiment of the present application, the humectant component is selected from one or more of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and hyaluronic acid, preferably polyvinyl alcohol.

[0014] Preferably, in a specific embodiment of the present application, the bactericide is selected from one or more of phenoxyethanol and bronopol, preferably phenoxyethanol.

[0015] Preferably, in a specific embodiment of the present invention, the wetting agent is an organosiloxane polyether.

[0016] Preferably, in a specific embodiment of the present invention, the pH regulator is selected from one or more of NaOH and KOH.

[0017] Another aspect of the present invention further provides a method for preparing any of the above-mentioned recoatable water-based acrylic inks, comprising the following steps: (1) Deionized water, pH regulator, dispersant and colorant are mixed evenly and added into a sand mill, and sand milled at room temperature for 1-2 hours to obtain a colorant paste; (2) Add the obtained colorant paste and pigment paste into the reactor and stir at room temperature for 1-2 hours; (3) While stirring, add the film-forming resin emulsion, and then add the moisturizing component, the wetting agent and the bactericide in sequence, and continue stirring for 1-2 hours to obtain the recoatable water-based acrylic ink.

[0018] Compared with the prior art, the present invention provides a recoatable water-based acrylic ink and a preparation method thereof, which has the following beneficial effects: 1. This invention, through the optimization of resin emulsions and modified hydrophobic agents, imparts high adhesion and flexibility to the coating film, and achieves a balance between the water resistance and wettability of the acrylic ink coating film. This effectively solves the problems of hue shift, interlayer adhesion failure, and coating integrity damage that occur during the recoating process of traditional acrylic inks, significantly improving the performance of inks in professional painting and industrial applications.

[0019] 2. The preferred modified hydrophobic agent added in the present invention constructs a hydrophobic micro-nanostructure with a lotus leaf effect on the coating surface, while retaining some active / polar segments or groups, thereby improving interlayer reactivity and adhesion, allowing the recoating ink to wet the underlying coating film, effectively improving the recoatability of the ink.

[0020] 3. The film-forming resin emulsion selected in the present invention imparts good adhesion and flexibility to the coating film, effectively preventing adhesion loss and mechanical damage during recoating, and significantly improving the durability and reliability of the ink.

[0021] 4. The ink of the present invention contains colorants such as titanium dioxide and pigment paste, which give the coating film bright colors and excellent hiding power. The addition of a polymer moisturizer extends the intermittent writing time of the ink and gives the ink good thixotropy, enabling the ink to maintain uniformity after long-term storage and ensure uniform and smooth ink discharge from the pen under shear force, thereby providing customers with a better writing experience.

[0022] 5. The formula design of the present invention breaks through the mechanism of traditional hydrophobic agents that only reduce the surface tension of the coating film. It not only achieves the hydrophobicity of the coating film surface, but also maintains the wettability of the coating film, overcomes the limitations of the existing technology, and has important practical value. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through practice of the present invention. It should be understood that the following description is only used to explain the present invention and is not intended to limit the present invention.

[0024] Example 1 A recoatable water-based acrylic ink, comprising, by mass fraction: Titanium dioxide 20%, red pigment paste 8%, acrylic resin emulsion 30%, water-based silicone-acrylate copolymer hydrophobic agent 4%, phosphate dispersant 2%, polyvinyl alcohol 2%, phenoxyethanol 0.2%, organosiloxane polyether 0.2%, NaOH 0.2%, and the rest is deionized water.

[0025] The preparation method of the recoatable water-based acrylic ink comprises the following steps: 1) Titanium dioxide, NaOH, phosphate dispersant and deionized water were added to a sand mill at the same time, and sand milled at room temperature for 1 hour to obtain a colorant paste; 2) Add colorant paste, red pigment paste and deionized water into the reaction kettle and stir at room temperature for 1 hour; 3) Add polyvinyl alcohol, organosiloxane polyether, phenoxyethanol, water-based organosilicon-acrylate copolymer hydrophobic agent and acrylic resin emulsion in sequence under stirring, and stir for 1 hour to prepare a recoatable water-based acrylic ink.

[0026] Referring to the preparation method of the recoatable water-based acrylic ink of Example 1, Examples 2 to 6 were prepared. The component ratios (by mass fraction) of Examples 2 to 6 are shown in Table 1.

[0027] Table 1 In order to better demonstrate the superiority of the present technical solution, the present invention provides Comparative Example 1 and Comparative Example 2 as shown in Table 2, and the preparation method thereof refers to Example 1.

[0028] Table 2 The surface drying time, dry rub fastness, wet rub fastness, recoat wettability, multi-coat adhesion, coating cracking and coating color mixing degree of various recoatable water-based acrylic inks in various examples and comparative examples were measured according to the following methods: Surface drying time: Use a test pen to draw 5 consecutive circles with a diameter of 20 mm-30 mm on the surface of the glass plate, repeat 3 times, record the time when there is no water mark on the surface of the coating, and gently wipe it with paper. The time when there is no ink mark on the paper is the surface drying time.

[0029] Dry erase resistance: Use a test pen to draw 5 consecutive circles with a diameter of 20 mm-30 mm on the surface of metal plate, glass plate, and PET film. Repeat 3 times. After the coating is completely dry, use a 500g weight to press on 3 layers of gauze and drag back and forth 3 times to observe whether there are obvious scratches on the surface of the coating.

[0030] Wet rub fastness: Use a test pen to draw 5 consecutive circles with a diameter of 20 mm-30 mm on the surface of metal plate, glass plate, and PET film. Repeat 3 times. After the coating is completely dry, use a 500g weight to press on 3 layers of gauze soaked in water and drag back and forth 3 times to observe whether there are obvious scratches on the surface of the coating.

[0031] Recoat Wettability: Use a test pen to scratch a 3 cm × 3 cm color block on the glass surface, repeat 3 times. After the coating is completely dry, use a test pen of another color to continue scratching a 2 cm × 2 cm color block on the basis of the original color block, repeat 3 times, and observe the wettability of the recoated coating.

[0032] Multi-coat adhesion: Use a test pen to scratch a 3 cm × 3 cm color block on the glass surface, repeat three times. After the coating is completely dry, use a test pen of another color to scratch a 2 cm × 2 cm color block on the original color block, repeat three times. After the coating is completely dry, use 3M tape to adhere the coating and then peel it off at a uniform speed to observe the adhesion of the coating on the 3M tape.

[0033] Coating cracking: Use a test pen to scratch a 3 cm × 3 cm color block on the surface of the glass plate, repeat 3 times. After the coating is completely dry, use a test pen of another color to continue scratching a 2 cm × 2 cm color block on the basis of the original color block, repeat 3 times, and observe whether there are fine cracks on the surface of the coating.

[0034] Coating color mixing: Use a test pen to draw a 3 cm × 3 cm color block on the surface of the glass plate, repeat 3 times. After the coating is completely dry, use a test pen of another color to continue drawing a 2 cm × 2 cm color block on the basis of the original color block, repeat 3 times, and observe whether the coating is dirty.

[0035] The test results of writing with the recoatable water-based acrylic ink prepared with the above-mentioned embodiments and comparative examples are shown in Table 3 below: Table 3 The recoatable water-based acrylic ink has excellent adhesion, fast drying, recoatability, water resistance and scratch resistance on various media surfaces, thus leaving a bright color line on the media surface. The two comparative examples are added with and without conventional hydrophobic agent, respectively. The ink added with conventional hydrophobic agent has excellent hydrophobicity, but it is difficult to wet the underlying paint film and the adhesion between the coating layers is poor. The ink without hydrophobic agent has the problems of dirty color and damage to the integrity of the underlying paint film. In addition, the adhesion and flexibility of the selected resin emulsion do not match, resulting in poor dry and wet rub fastness of the ink. The recoatable water-based acrylic ink prepared by using the above-mentioned formulation of each example has the test results of storage performance as shown in Table 4.

[0036] Table 4 The above-mentioned recoatable water-based acrylic ink has no change in physicochemical indicators after being stored at low temperature (-10℃) and high temperature (50℃) for one month; the intermittent writing performance can reach 1-2 hours at normal temperature and humidity.

[0037] The preferred embodiments of the above disclosed application are only used to help explain the application. The preferred embodiments do not describe all the details and limit the application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the specification. The specification selects and describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited by the claims and their entire scope and equivalents.

Claims

1. A recoatable water-based acrylic ink, characterized in that: Measured by quality score, including: Colorant 5-40%, pigment paste 0-25%, film-forming resin emulsion 20-40%, modified hydrophobic agent 1-5%, dispersant 1-4%, moisturizing component 2-6%, preservative 0.2-0.5%, wetting agent 0.1-0.5%, pH adjuster 0.1-0.5%, and the rest is deionized water; The film-forming resin emulsion is one or more of acrylic resin emulsion, polyurethane resin emulsion, and epoxy resin emulsion; The modified hydrophobic agent is one or more of a water-based organic silicon-acrylate copolymer, a nano-composite hydrophobic agent, and a modified polysiloxane copolymer.

2. A recoatable water-based acrylic ink according to claim 1, characterized in that: Measured by quality score, including: Colorant 5-25%, pigment paste 0-25%, film-forming resin emulsion 30-40%, modified hydrophobic agent 3-5%, dispersant 1-3%, moisturizing component 2-6%, preservative 0.2-0.5%, wetting agent 0.1-0.5%, pH adjuster 0.1-0.5%, and the rest is deionized water; More preferably, the colorant is 5-25%, the pigment paste is 0-25%, the film-forming resin emulsion is 30-40%, the modified hydrophobic agent is 3-5%, the dispersant is 1-3%, the moisturizing component is 2%, the preservative is 0.2%, the wetting agent is 0.2%, the pH adjuster is 0.2%, and the rest is deionized water; The film-forming resin emulsion is an acrylic resin emulsion; and the modified hydrophobic agent is a water-based organosilicon-acrylate copolymer.

3. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The colorant comprises one or more of titanium dioxide, zinc oxide, and lithopone, preferably titanium dioxide.

4. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The pigment paste includes one or more of red pigment paste, blue pigment paste, and green pigment paste.

5. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The dispersant is a phosphate surfactant.

6. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The moisturizing component is selected from one or more of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, and hyaluronic acid, preferably polyvinyl alcohol.

7. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The bactericide is selected from one or more of phenoxyethanol and bronopol, preferably phenoxyethanol.

8. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The wetting agent is organosiloxane polyether.

9. A recoatable water-based acrylic ink according to claim 1 or 2, characterized in that: The pH regulator is selected from one or more of NaOH and KOH.

10. The method for preparing the recoatable water-based acrylic ink according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: (1) Deionized water, pH regulator, dispersant and colorant are mixed evenly and added into a sand mill, and sand milled at room temperature for 1-2 hours to obtain a colorant paste; (2) Add the obtained colorant paste and pigment paste into the reactor and stir at room temperature for 1-2 hours; (3) While stirring, add the film-forming resin emulsion, and then add the moisturizing component, the wetting agent and the bactericide in sequence, and continue stirring for 1-2 hours to obtain the recoatable water-based acrylic ink.

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