Researchers worldwide have been striving to enhance the dispersion of carbon black in water. Various methods, including the use of dispersants, surface grafting, and surface oxidation modification, have been explored to improve carbon black's dispersion. However, surface grafting and surface oxidation modification, while effective in achieving stability by modifying the pigment's surface, are complex and costly, making them unsuitable for neutral ink color paste production. In contrast, the dispersant-based dispersion method offers advantages such as cost-effectiveness, process simplicity, and easy control over yield, making it a widely adopted approach.
Our study focused on creating carbon black ink for neutral inks with a particle size distribution (D50) of 100-120nm, a pigment content of 30%, and a viscosity of 350 mPa·s. The research delved into several critical aspects:
We examined three types of carbon black—FW200, Printex U, and MA-100—each with distinct physicochemical properties. By evaluating their wetting characteristics and their impact on ink viscosity and particle size distribution, we determined that MA-100 is the suitable pigment for neutral ink production.
We investigated three representative dispersants: small molecule anionic NNO, polymer non-ionic PVP, and polymer anionic SMA-NH4. Through measurements of ζ-potential, sedimentation rate, and rheological properties of carbon black MA-100 under different conditions, we explored how dispersant structure affects dispersion stability. Our findings highlight that SMA-NH4, at pH 8 with a 4% dosage, yielded ink with outstanding performance.
Considering various grinding methods (ball milling, high-pressure homogenization, and rod-pin milling) and process parameters, we sought to identify the optimal approach for preparing carbon black ink for neutral inks. The most effective process involved a combination of high-speed dispersion, high-pressure homogenization, and rod-pin milling. We used zirconia beads with a diameter of 0.5mm in the rod-pin mill, operated at a speed of 1500rpm, with a 70% filling rate, and a milling time of 1 hour, resulting in ink with the desired particle size distribution (D50) of 100-120nm.
Subsequently, we filled the prepared ink into pens and subjected them to storage under varying conditions, including room temperature, high temperature, and moderate temperature, for two months. Regular tests were conducted to evaluate writing performance. The results demonstrated that ink prepared with SMA-NH4 as the dispersant maintained excellent physicochemical and rheological properties. Even after two months of storage, its writing performance remained satisfactory.
A specified amount of dispersant is added to deionized water, followed by thorough mixing to dissolve the dispersant at a specific speed using an electric stirrer. Defoamers and preservatives are then added, and pigment is introduced. After complete mixing, a premix solution is obtained.
Deionized water is used to dissolve a specified amount of dispersant (SMA-NH4), followed by stirring. Carbon black is gradually added, with the added dispersant constituting 20% of the carbon black weight and carbon black accounting for 30% of the total slurry weight. Different dispersion times are employed with the three milling methods (ball milling, high-pressure homogenization, and rod-pin milling) to prepare water-based carbon black ink.
Particle Size and Size Distribution Analysis:Particle size and distribution were measured using the NANOPHOX nanoparticle size analyzer, which utilizes photon cross-correlation spectroscopy. The system employs a helium-neon laser as the light source, with a wavelength of 632.8 nm, a laser power of 10 mV, and a detection angle of 90°. The testing temperature is maintained at 25°C, and the sample volume is adjusted to ensure a scattering rate exceeding 0.5 for enhanced accuracy.
A comparison of different grinding methods, including ball milling, high-pressure homogenization, and rod-pin milling, revealed that rod-pin milling achieved the smallest particle sizes and the highest grinding efficiency.
To determine the effects of factors such as bead size and grinding speed on ink particle size, experiments were conducted. The optimal parameters identified were zirconia beads with a diameter of 0.5mm, a grinding speed of 1500rpm, and a 70% filling rate.
Recognizing the limitations of individual milling methods, a combination process was chosen. This approach involves the initial creation of a soft fixed paste with part of the liquid and pigment, followed by high-speed dispersion, coarse grinding in a horizontal sand mill, and fine grinding in a rod-pin mill. This combination maximizes efficiency while achieving fine particle size and uniform shape in the ink particles.
The quest for achieving excellence in carbon black ink preparation unveils a pivotal player in the process - ceramic grinding balls. As researchers globally strive to enhance the dispersion of carbon black in water, our study showcases the indispensable role played by these ceramic spheres in optimizing ink characteristics.
Researchers have encountered numerous challenges in dispersing carbon black efficiently. While methods like surface grafting and oxidation modification offer stability, they are complex and costly. In contrast, the dispersant-based dispersion method, coupled with the strategic use of ceramic grinding balls, emerges as a game-changer. These balls facilitate precision in the grinding process, ensuring the attainment of the desired particle size and distribution critical for superior ink performance.
Our study delved into critical aspects, starting with carbon black selection. Evaluating three distinct types - FW200, Printex U, and MA-100 - revealed that MA-100 stood out due to its wetting characteristics, minimal impact on ink viscosity, and ability to achieve the targeted particle size distribution. The subsequent grinding process, empowered by ceramic grinding balls, proved to be instrumental in optimizing efficiency.
The influence of dispersant structure was a key focus, with SMA-NH4 identified as the optimal dispersant. Its interaction with carbon black was enhanced by the efficient action of ceramic grinding balls during the dispersion process. The precise grinding ensured that the ink maintained outstanding physicochemical and rheological properties, even after prolonged storage.
The heart of our optimization process lay in refining grinding methods, and ceramic grinding balls played a crucial role in this endeavor. The combination of high-speed dispersion, high-pressure homogenization, and rod-pin milling, facilitated by these ceramic spheres, yielded ink with the desired particle size distribution (D50) of 100-120nm. The meticulous use of zirconia beads, with a diameter of 0.5mm, further accentuated the efficiency of the grinding process.
Following ink preparation, the ink was subjected to diverse storage conditions, demonstrating that the use of ceramic grinding balls contributed significantly to the ink's longevity. Ink prepared with SMA-NH4 as the dispersant, in conjunction with ceramic grinding balls, showcased consistent writing performance even after two months of storage under varying conditions.
The choice of ceramic grinding balls in our study was not arbitrary. The use of zirconia beads, with their optimal size and material characteristics, played a pivotal role in achieving fine particle size and uniform shape in the ink particles. These ceramic grinding balls acted as catalysts for precision, ensuring that the ink met the stringent specifications for neutral ink production.
our research successfully produced carbon black ink for neutral inks with exceptional performance characteristics. The study covered various aspects, including carbon black selection, the influence of dispersant structure, and the impact of grinding methods and parameters. The combination of high-speed dispersion, high-pressure homogenization, and rod-pin milling proved to be a highly effective approach for achieving the desired particle size and distribution. The resulting ink, prepared with SMA-NH4 as the dispersant, maintained its quality even after two months of storage under different conditions.
Submit your demand,
we will contact you ASAP.
Sanxin New Materials Co., Ltd. focus on producing and selling ceramic beads and parts such as grinding media, blasting beads, bearing ball, structure part, ceramic wear-resistant liners, Nanoparticles Nano Powder
English
English
Russian
French
Spanish
Portuguese
Arabic
