Modified carbon black for water-based ink as well as preparation method and application of modified carbon black

Abstract

The invention discloses modified carbon black for water-based ink as well as a preparation method and application thereof, and the preparation method of the modified carbon black comprises the following steps: mixing carbon black with a hydrogen peroxide solution, and then carrying out pre-oxidation reaction to obtain pre-oxidized carbon black; mixing the pre-oxidized carbon black with a potassium permanganate solution dissolved in strong acid, and carrying out oxidation reaction to obtain oxidized carbon black; adding the oxidized carbon black into dilute acid for soaking, filtering and washing to obtain the modified carbon black. Carbon black is fully oxidized, the dispersion stability of carbon black particles in water-based ink is improved, when the carbon black particles are applied to the water-based ink, the carbon black particles have excellent blue phase, blackness and stability at the same time, and finally the carbon black particles can be widely popularized and applied to the industries of automobile paint, industrial paint and ink-jet printing.

Description

Technical Field

[0001] The present invention belongs to the technical field of inks, and particularly relates to a modified carbon black for water-based inks, a preparation method thereof, and an application thereof. Background Art

[0002] Carbon black is nano-scale carbon particles formed by pyrolysis of hydrocarbon substances at high temperatures, and has good electrical conductivity, thermal conductivity, and adsorption properties. High-pigment carbon black is a special carbon black with extremely high blackness, excellent coloring power, and good dispersibility, and is widely used in high-grade inks, automotive topcoats, cosmetics and other fields. The water-based system has excellent prospects in terms of safety, construction convenience, and user experience compared to the traditional oil-based system.

[0003] Due to the characteristics of small particle size, large specific surface area, and high surface free energy of pigment carbon black itself, strong aggregation forces are easily formed between carbon black particles, making it show hydrophobic properties and difficult to disperse in water-based systems. Currently, there are various carbon black oxidation modification processes for improving the dispersion performance of carbon black in water-based systems. For example, using nitrogen-containing oxidants to chemically oxidize carbon black, but this oxidant not only pollutes the environment, but also easily introduces other by-products and impurities, and the process route for realizing carbon black modification is long and the treatment process is cumbersome and complex. Considering that pigment carbon black particles cannot be fully dispersed in water-based systems, it also leads to the fact that carbon black pastes cannot exhibit high blackness and high blue phase, and thus cannot meet the blackness and blue phase requirements of the high-end market. Therefore, it is of great significance to improve the dispersion stability of pigment carbon black in water so that it can be applied to water-based inks. Summary of the Invention

[0004] Based on the above technical problems, the present invention provides a modified carbon black for water-based inks, a preparation method thereof, and an application thereof. By fully oxidizing carbon black, the dispersion stability of carbon black particles in water-based inks is improved. When it is applied to water-based inks, it can simultaneously have excellent blue phase, blackness, and stability, and can ultimately be widely promoted and applied in the automotive paint, industrial paint, and inkjet printing industries.

[0005] A preparation method of a modified carbon black for water-based inks proposed by the present invention includes the following steps: S1. Mix carbon black with hydrogen peroxide solution and carry out a pre-oxidation reaction to obtain pre-oxidized carbon black; S2. Mix the pre-oxidized carbon black with a potassium permanganate solution dissolved in strong acid and carry out an oxidation reaction to obtain oxidized carbon black; S3. Add the oxidized carbon black to dilute acid for soaking, filter, and wash with water to obtain oxidized carbon black, that is, obtain the modified carbon black.

[0006] Compared with the carbon black obtained by traditional oxidation methods, the degree of oxidation is lower and it cannot achieve the effect of stable dispersion in water. In the present invention, hydrogen peroxide is first used to pretreat the carbon black to activate it, and then potassium permanganate dissolved in strong acid is used to deeply oxidize the carbon black, so that the structural properties of the carbon black surface change, and some oxygen-containing groups with good hydrophilic properties (-COOH, -OH, etc.) are introduced, significantly improving the dispersibility and stability of the carbon black in the aqueous system, solving the technical problem of low dispersion stability of carbon black in the aqueous system in the traditional carbon black modification process, and making the modified carbon black exhibit high blackness and high blue phase, thus making the product more upscale and giving a better visual impression.

[0007] Preferably, in step S1, the carbon black is furnace black; The average particle size of the furnace black is 20 - 25 μm, and the nitrogen adsorption specific surface area is 200 - 300 m 2 / g.

[0008] Preferably, in step S1, the concentration of the hydrogen peroxide is 20 - 30 wt%, the pre-oxidation reaction temperature is 10 - 30 °C, and the time is 20 - 40 min.

[0009] Preferably, in step S2, the strong acid is sulfuric acid, and the concentration is 35 - 50 wt%; The mass ratio of the pre-oxidized carbon black to potassium permanganate is 1:0.1 - 0.3.

[0010] Preferably, in step S2, the oxidation reaction temperature is 40 - 80 °C, and the time is 4 - 12 h.

[0011] Preferably, in step S3, the dilute acid is dilute hydrochloric acid, and the concentration is 1 - 10 wt%; The soaking time is 6 - 8 h.

[0012] Preferably, in step S3, the oxidized carbon black is also modified, and the modification includes first performing a coupling reaction on the oxidized carbon black with a tertiary amine-based silane coupling agent, and then performing a quaternization reaction with (3-bromopropyl) trimethylammonium bromide; Preferably, the tertiary amine-based silane coupling agent is at least one of N, N-diethylaminopropyltrimethoxysilane, (diethylaminomethyl) trimethoxysilane, or N-imidazolylpropyltriethoxysilane; Preferably, the mass ratio of the oxidized carbon black, the tertiary amine-based silane coupling agent, and (3-bromopropyl) trimethylammonium bromide is 1:0.01 - 0.05:0.01 - 0.1.

[0013] In the present invention, the surface of oxidized carbon black is grafted and modified with a tertiary amine silane coupling agent to introduce a tertiary amine group onto the surface of the oxidized carbon black. It can undergo a quaternization reaction with (3-bromopropyl) trimethyl ammonium bromide, and finally a bisquaternary ammonium salt group is introduced onto the surface of the carbon black. It has high polarity, is hydrophilic and easy to disperse at the same time. Therefore, it can further change the polarity of the carbon black itself, and further increase the dispersibility and stability of the carbon black in the aqueous system, ensuring the suspension stability of the color paste and preventing the carbon black particles from settling easily. In addition, the bisquaternary ammonium salt group can form an electrostatic adsorption with the waterborne acrylic resin, thereby increasing the compatibility between the obtained modified carbon black and the waterborne acrylic resin, and further improving the adhesion ability and storage stability of the ink.

[0014] The present invention also provides a modified carbon black for waterborne ink, which is prepared by the above preparation method.

[0015] The present invention also provides a waterborne ink, which comprises the above modified carbon black.

[0016] Preferably, the waterborne ink further comprises a waterborne acrylic resin; Preferably, the dosage of the waterborne acrylic resin is 30-60 wt% of the total amount of the waterborne ink, and the dosage of the modified carbon black is 1-30% of the total amount of the waterborne ink.

[0017] Advantages of the present invention: (1) In the present invention, by selecting a suitable carbon black, pre-oxidizing it with hydrogen peroxide first, and then under suitable reaction conditions, making the carbon black undergo a deep oxidation reaction with potassium permanganate dissolved in strong acid, the oxidized carbon black has good hydrophilicity and can have excellent dispersion stability in the aqueous system.

[0018] (2) In the present invention, the oxidized carbon black is also modified by the surface modification method, and the prepared modified carbon black can be more stably dispersed in water and can be better compatible with the waterborne acrylic resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the infrared spectrum diagram of the modified carbon black described in Example 1 of the present invention; Figure 2 It is the structural schematic diagram of the modified carbon black described in Example 4 of the present invention; Figure 3 It is the effect diagram of the ink product corresponding to Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Next, the technical solutions of the present invention will be described in detail through specific examples. However, it should be clearly stated that these examples are for illustrative purposes only and should not be construed as limiting the scope of the present invention.

[0021] Example 1

[0022] This example presents a preparation method of modified carbon black for water-based ink, which is prepared by the following method: (1) Add furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) into 30 wt% hydrogen peroxide solution, stir and react for 30 min, then evaporate the water to dryness to obtain pre-oxidized carbon black; (2) Add the pre-oxidized carbon black into a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%), the content of potassium permanganate in the solution is 3.6 wt%, the dosage of potassium permanganate is 20 wt% of the furnace black. Stir and react for 8 h under the water bath condition of 60 °C, wait for it to cool naturally to room temperature, add it to dilute hydrochloric acid (concentration is 5 wt%) and soak for 7 h, then filter, wash with water, and dry to obtain the modified carbon black.

[0023] The infrared spectrum of the modified carbon black is as shown in Figure 1 As shown, referring to Figure 1 it can be seen that the -OH bending vibration absorption peak at about 1500 cm -1 in the modified carbon black, the -C=O stretching vibration absorption peak at about 1750 cm -1 in the modified carbon black, the -COOH peak at about 2300 cm -1 in the modified carbon black, and the -OH stretching vibration absorption peak at about 3600 cm -1 in the modified carbon black are significantly enhanced, indicating that the oxygen-containing functional groups of the carbon black, especially -OH and -C=O, are significantly increased after oxidation modification.

[0024] Example 2

[0025] This example presents a preparation method of modified carbon black for water-based ink, which is prepared by the following method: (1) Add furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) into 20 wt% hydrogen peroxide solution, stir and react for 20 min, then evaporate the water to dryness to obtain pre-oxidized carbon black; (2) Add the pre-oxidized carbon black into a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%), the content of potassium permanganate in the solution is 3.6 wt%, the dosage of potassium permanganate is 10 wt% of the furnace black. Stir and react for 4 h under the water bath condition of 80 °C, wait for it to cool naturally to room temperature, add it to dilute hydrochloric acid (concentration is 5 wt%) and soak for 7 h, then filter, wash with water, and dry to obtain the modified carbon black.

[0026] Example 3

[0027] This example presents a preparation method of modified carbon black for water-based ink, which is prepared by the following method: (1) Add furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) into 30 wt% hydrogen peroxide solution, stir and react for 40 min, then evaporate the water to dryness to obtain pre-oxidized carbon black; (2) Add the pre-oxidized carbon black into a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%). The content of potassium permanganate in the solution is 3.6 wt%, and the dosage of potassium permanganate is 30 wt% of the furnace black. Stir and react for 12 h under the water bath condition of 40 °C, wait for it to cool naturally to room temperature, add it to dilute hydrochloric acid (concentration is 5 wt%) and soak for 7 h, filter by suction, wash with water, and dry to obtain the modified carbon black.

[0028] Example 4

[0029] This example provides a preparation method of modified carbon black for water-based ink, which is prepared by the following method: (1) Add furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) into 30 wt% hydrogen peroxide solution, stir and react for 30 min, then evaporate the water to dryness to obtain pre-oxidized carbon black; (2) Add the pre-oxidized carbon black into a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%). The content of potassium permanganate in the solution is 3.6 wt%, and the dosage of potassium permanganate is 20 wt% of the furnace black. Stir and react for 8 h under the water bath condition of 60 °C, wait for it to cool naturally to room temperature, add it to dilute hydrochloric acid (concentration is 5 wt%) and soak for 7 h, filter by suction, wash with water, and dry to obtain oxidized carbon black; (3) Add the oxidized carbon black into water and stir to disperse evenly, add N,N-diethylaminopropyltrimethoxysilane. The dosage of N,N-diethylaminopropyltrimethoxysilane is 3 wt% of the oxidized carbon black. Stir and react for 3 h at 60 °C, then add (3-bromopropyl)trimethylammonium bromide. The dosage of (3-bromopropyl)trimethylammonium bromide is 5 wt% of the oxidized carbon black. Stir and react for 12 h at 80 °C, then centrifuge, wash with water, and dry to obtain the modified carbon black.

[0030] Comparative Example 1 This comparative example provides a preparation method of modified carbon black for water-based ink, which is prepared by the following method: Add furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) into 30 wt% hydrogen peroxide solution, stir and react for 30 min, then evaporate the water to dryness to obtain the modified carbon black.

[0031] Comparative Example 2 This comparative example presents a preparation method for modified carbon black for water-based ink, which is prepared by the following method: The furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) was added to a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%). The content of potassium permanganate in the solution was 3.6 wt%, and the dosage of potassium permanganate was 20 wt% of the furnace black. After stirring and reacting for 8 h under the condition of a 60 °C water bath, it was allowed to cool naturally to room temperature, then added to dilute hydrochloric acid (concentration is 5 wt%) and soaked for 7 h, filtered by suction, washed with water, and dried to obtain the modified carbon black.

[0032] Comparative Example 3 This comparative example presents a preparation method for modified carbon black for water-based ink, which is prepared by the following method: The furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) was added to a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%). The content of potassium permanganate in the solution was 3.6 wt%, and the dosage of potassium permanganate was 20 wt% of the furnace black. After stirring and reacting for 8 h under the condition of a 60 °C water bath, it was allowed to cool naturally to room temperature, then added to 30 wt% hydrogen peroxide solution and stirred for 30 min, then added to dilute hydrochloric acid (concentration is 5 wt%) and soaked for 7 h, filtered by suction, washed with water, and dried to obtain the modified carbon black.

[0033] Comparative Example 4 This comparative example presents a preparation method for modified carbon black for water-based ink, which is prepared by the following method: (1) The furnace black (average particle size is 23 μm, nitrogen adsorption specific surface area is 260 m 2 / g) was added to 30 wt% hydrogen peroxide solution and stirred for 30 min, then the water was evaporated to dryness to obtain pre-oxidized carbon black; (2) The pre-oxidized carbon black was added to a potassium permanganate solution dissolved in sulfuric acid (concentration is 45 wt%). The content of potassium permanganate in the solution was 3.6 wt%, and the dosage of potassium permanganate was 20 wt% of the furnace black. After stirring and reacting for 8 h under the condition of a 60 °C water bath, it was allowed to cool naturally to room temperature, then added to dilute hydrochloric acid (concentration is 5 wt%) and soaked for 7 h, filtered by suction, washed with water, and dried to obtain oxidized carbon black; (3) The oxidized carbon black was added to water and stirred to disperse evenly, then a quaternized silane coupling agent (3-(trimethoxysilylpropyl)dimethyloctadecylammonium chloride) was added. The dosage of the quaternized silane coupling agent was 3 wt% of the oxidized carbon black. After stirring and reacting for 3 h at 60 °C, centrifuged, washed with water, and dried to obtain the modified carbon black.

[0034] The modified carbon blacks obtained in the examples and comparative examples were used in water-based inks. The water-based inks included, by mass percentage: 45 wt% of water-based acrylic resin, 10 wt% of modified carbon black, and the balance was water. A 80-μm wire bar was used to scrape on black and white cardboard. The results of the ink products corresponding to Example 1 were as Figure 3 shown. Then, a six-angle color difference meter (BYK7030) was used to measure the color data (L, a, b) at 45° to calculate the blackness (Mc, My) and the blue phase dM. At the same time, the appearance state was observed. If soft sedimentation occurred, it indicated poor storage stability. The specific test results are shown in Table 1 below.

[0035]

[0036] As can be seen from the above table, the modified carbon blacks provided in the examples of the present invention have excellent blue phase (the smaller the b value, the larger the dM value, and the more excellent the blue phase), blackness (the larger the My value, the higher the blackness), and stability (no soft sedimentation) when used in water-based inks; compared with the single quaternary ammonium salt group modified carbon black (Comparative Example 4), the double quaternary ammonium salt group modified carbon black (Example 4) has obvious modification effects on blackness and blue phase.

[0037] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A preparation method of modified carbon black for water-based ink, characterized in that, It includes the following steps: S1. Mix carbon black with hydrogen peroxide solution and carry out a pre-oxidation reaction to obtain pre-oxidized carbon black; S2. Mix the pre-oxidized carbon black with a potassium permanganate solution dissolved in strong acid and carry out an oxidation reaction to obtain oxidized carbon black; S3. Immerse the oxidized carbon black in dilute acid, filter, wash with water, and obtain oxidized carbon black, which is the modified carbon black.

2. The preparation method of the modified carbon black for water-based ink according to claim 1, characterized in that, In step S1, the carbon black is furnace black; The average particle size of the furnace black is 20-25 μm, and the nitrogen adsorption specific surface area is 200-300 m 2 / g.

3. The preparation method of the modified carbon black for water-based ink according to claim 1, characterized in that, In step S1, the concentration of hydrogen peroxide is 20 - 30 wt%, the temperature of the pre-oxidation reaction is 10 - 30 °C, and the time is 20 - 40 min.

4. The preparation method of the modified carbon black for water-based ink according to any one of claims 1-3, characterized in that, In step S2, the strong acid is sulfuric acid with a concentration of 35 - 50 wt%; The mass ratio of the pre-oxidized carbon black to potassium permanganate is 1:0.1 - 0.

3.

5. The preparation method of the modified carbon black for water-based ink according to any one of claims 1-3, characterized in that, In step S2, the temperature of the oxidation reaction is 40 - 80 °C, and the time is 4 - 12 h.

6. The preparation method of the modified carbon black for water-based ink according to any one of claims 1-3, characterized in that, In step S3, the dilute acid is dilute hydrochloric acid with a concentration of 1 - 10 wt%; The soaking time is 6 - 8 h.

7. The preparation method of the modified carbon black for water-based ink according to any one of claims 1-3, characterized in that, In step S3, it also includes modifying the oxidized carbon black. The modification includes carrying out a coupling reaction on the oxidized carbon black with a tertiary amine-based silane coupling agent first, and then carrying out a quaternization reaction with (3-bromopropyl) trimethylammonium bromide to obtain; The tertiary amine-based silane coupling agent is at least one of N, N-diethylaminopropyltrimethoxysilane, (diethylaminomethyl) trimethoxysilane, or N-imidazolylpropyltriethoxysilane; The mass ratio of the oxidized carbon black, the tertiary amine-based silane coupling agent, and (3-bromopropyl) trimethylammonium bromide is 1:0.01 - 0.05:0.01 - 0.

1.

8. A modified carbon black for water-based ink, characterized in that, It is prepared by the preparation method described in any one of claims 1 - 7.

9. An aqueous ink, characterized in that, It includes the modified carbon black described in claim 8.

10. The water-based ink according to claim 9, characterized in that, It also includes an aqueous acrylic resin; the dosage of the aqueous acrylic resin is 30 - 60 wt% of the total amount of the aqueous ink, and the dosage of the modified carbon black is 1 - 30 wt% of the total amount of the aqueous ink.

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