1. Carbon black is used in the paper industry as a black pigment to produce black, gray, or dark paper and cardboard
Compared with other organic pigments, carbon black is relatively cheap, and has good light resistance and chemical resistance. Moreover, it has good coloring and shading properties, and can also make the paper conductive. Therefore, paper colored with carbon black is often used in decoration materials, light-proof packaging materials (such as packaging paper for photosensitive films), various album papers, high-voltage cable paper, etc.
There are two coloring methods for black paper. One is the overall coloring method, that is, adding forming agents, reinforcing agents, fillers and carbon black to the pulp, mixing and dispersing them in a beater, and then making paper. The amount of carbon black added About 6%-7% of solid content. Another method is to contact and color the finished coating liquid or ink on the surface of the paper. Because the overall coloring quality is uniform and stable, and the durability is good, it is a commonly used method.
If powdered or granular carbon black is directly used to make paper, due to the hydrophobicity of commonly used carbon black, it is difficult to mix and disperse in water-based pulp, and it is easy to pollute equipment and the environment. Therefore, cationic or nonionic wetting agents can be added to carbon black, which is to disperse and mix carbon black in pulp.
Carbon black for papermaking can be selected from pigment carbon black with a particle size of 20-30nm, a surface area of 80-120㎡/g, a DBP of 100-140ml/100g, and a tinting power of 100-110%.
2. Application of carbon black in fiber
There are two methods of fiber coloring, one is the traditional dyeing method, that is, dyeing the fiber with organic dyes after spinning or weaving into cloth; Melt coloring. Currently the most widely used for dope coloring
The requirements for carbon black are: good blackness (preferably with blue phase), good dispersion and high purity. For this reason, the general carbon black chooses the particle size of 20-25nm, DBP100-120ml/100g, and the oil furnace pigment carbon black without oxidation treatment. Because the particle size is too small and the structure is too low, the carbon black is difficult to disperse well in the resin. , and the particle size is too large will reduce the blackness of carbon black, and lead to too much addition (generally the content of carbon black in the resin before drawing is 1%-2%) and too high structure will make the melt viscosity higher. Unlike carbon black in coatings and ink applications, carbon black with more surface functional groups (that is, surface-treated carbon black) cannot be used for dope coloring. The purity of carbon black is very important, because before the melt is drawn To ensure the quality of the wire drawing, it must be filtered through a screen with a very small pore size. When there are too many impurities, the screen will be blocked and the production will be affected. This is also a factor that does not require surface treatment of carbon black. When more carbon black is added, such as 10-15% conductive carbon black, it can not only be colored, but also have conductive properties, and can be used to make anti-static work clothes, anti-static carpets, etc.
3. Application of carbon black in cement
Carbon black is often used in cement or asbestos cement coloring, that is, black or gray color finding agent, and also used in roofing materials, asbestos cement boards, cement building boards, and concrete pavement of expressways.
Since cement or asbestos cement is operated and used in water-based media, it has the same requirements for carbon black as papermaking, and it is best to add a wetting agent and carbon black that is easy to disperse in water
Carbon black can also be used as a crushing accelerator in the manufacture of Portland cement, which can shorten the crushing time and make the particle size finer to increase the fluidity of the dry powder. If 1.3% is added, the crushing time can be shortened by one-third
For example, if the cement dry powder is coated with 0.2%-1% asphalt film, and then mixed with 0.2-1.5% carbon black, a wave with low water permeability, high compressive strength and strong adhesion to steel bars can be produced. Tran cement, this cement contains 2%-5% gypsum,
Add carbon black and carbon fiber to concrete, but concrete is conductive
4. Application of carbon black in refractories
Carbon black can be used to make basic refractory bricks, such as magnesia bricks or magnesia bricks, and the life of refractory bricks can be extended due to the reduction of intrusion and penetration of high-temperature materials. The application formula is such as 75-95 parts (mass) of fused or sintered magnesia, 5-25 parts of graphite, 2-10 parts of carbon black, 2-10 parts of pitch powder and 0.5-5 parts of urea-formaldehyde resin. After the film is formed, it is baked at 100-300°
Black cat pigment carbon black color black is carbon black used as coloring pigment in ink, paint, paint, plastic and other products. According to the coloring strength (or blackness) and particle size, it is generally divided into four types: high pigment carbon black, medium pigment carbon black, ordinary pigment carbon black and low pigment carbon black. It is mainly produced by oil furnace method and tank method.