As an amorphous carbon, pigment carbon black is a kind of fine black powder in physical form, with a large specific surface area ranging from 10-3000m2/g. A substance produced by incomplete combustion or heating under conditions of insufficient air. Pigment carbon black can be used as black raw material for the manufacture of inks, paints, coatings, etc. Carbon black is a tiny black powder produced by incomplete combustion of carbonaceous raw materials. It is pure black tiny particles or powder. The level of blackness, the size of particle fineness, and the specific gravity are different from the raw materials used and the manufacturing method. Insoluble in water, acid and alkali; can burn into carbon dioxide in the air. The main component is carbon, and it also contains a small amount of hydrogen, oxygen, sulfur, ash, tar and water. In terms of structural composition, it can be divided into high structure and low structure, and its structure is expressed by the degree to which particles are aggregated into chains or grapes. The finished product consisting of aggregates consisting of aggregate morphology, size, and number of particles in each aggregate is called high-structure pigmented carbon black. At present, the oil absorption value is often used to indicate the level of the structure. The larger the oil absorption value, the higher the structure, and it is easy to form a space network channel, and it is not easy to be damaged. High-structure products have fine particles, densely packed network chains, large specific surface area, and more particles per unit mass, which is conducive to the formation of chain-type conductive structures in polymers. Acetylene carbon black is the best among many varieties. Particles with a wider particle size distribution confer electrical conductivity to the polymer than particles with a narrower distribution, and this phenomenon is explained statistically. For products with a wide particle size distribution, a small number of large-diameter particles need a large number of particles to compensate, and the same average particle size distribution has a larger total number of particles than a narrow distribution.
Pigment carbon black particles can absorb, reflect, refract and transmit light, so they can present certain colors. The blacker the carbon black of screen printing ink, the higher its acid value (PH value is between 2.5 and 4.5), the stronger the adsorption capacity, and it is evenly distributed in the binder in the state of particles. Generally, the pigment is required to have bright color, proper Excellent tinting power and hiding power, and high dispersion. Screen printing ink is easy to adjust and operate before printing, after printing and during the printing process. After printing, the printed matter appears to be full of imprints, bright colors, high gloss, gorgeous and rich, and the printing of complex patterns can also achieve rich levels. It can print bright and High gloss color and other features. During the printing process, an appropriate amount of PH value stabilizer should be added at regular intervals to keep the water-based ink in a good printing state. Generally speaking, when the viscosity of the water-based ink is too high and the pH value is too low, or when the printing machine is running at a relatively fast speed, air bubbles are likely to occur. Will affect the quality of printed matter.
Ordinary screen printing ink carbon black PH value is almost neutral, so its adsorption capacity is not obvious. Since the adsorption capacity has a special influence on the dryness of the paint, the drying rate of the paint film is often reduced due to the adsorption of the drier in the paint. When the pH value is below 4, the greater the acidity, the greater the adsorption capacity of the drier, and the more obvious the effect on the drying performance. The anti-drying effect of pigment carbon black is not shown immediately after the paint is made, but after a period of time after it is completely or partially adsorbed on the drier (storage period). Therefore, when designing the paint formulation, an appropriate increase in the amount of drier should be considered. Mitsubishi Pigment Carbon Black is an imported pigment carbon black product. It has been used as silk screen printing ink carbon black in my country for many years. Its products have the advantages of easy dispersion, good wettability, and stable performance. They are used in my country's coatings, inks and other industries. wider.