What are the technical indicators of pigment carbon black?
The technical indicators of pigment carbon black include particle size, specific surface area, DBP absorption value, tinting strength, volatile matter, pH value, hue, heat loss, density, blackness and other indicators. The meanings of each indicator are different, and the following are respectively Introduce the meaning of these technical indicators.
The meaning of various indicators of pigment carbon black
1. Particle size:
The particle size of carbon black refers to the primary particle size of carbon black, which is the average value of a certain number of particle sizes. It is different from the shape of carbon black, that is, the particle size of carbon black has nothing to do with whether carbon black is granule or powder. It is tested by electron microscopy and is the average value of a certain particle size. Pigment carbon black can be divided into high pigment carbon black, medium pigment carbon black and low pigment carbon black according to the particle size.
2. Specific surface area:
The specific surface area index of pigment carbon black represents the surface area per gram of carbon black. It can be determined by BET (Brunauer-Enmet-Teller), that is, low-temperature nitrogen adsorption method. The simple and convenient iodine adsorption method commonly used in the world can also be used. The measurement result represents the surface area per gram, (m2/g).
3.DBP absorption value (absorption value):
is the adsorption of carbon black with dibutyl phthalate (DBP). The amount of DBP consumed when the adsorption is balanced represents the size of the carbon black structure. The higher the adsorption value, the higher the carbon black structure, and vice versa.
4. Tinting power:
The tinting strength of pigment carbon black, also known as tinting strength, is an important indicator of pigment carbon black. It indicates the ability of carbon black to dye white bodies. Generally, the tinting power is high and its covering performance is good. The test method is carried out according to ASTM-3265.
5. Volatile content of carbon black:
It is the oxygen-containing functional groups (carboxyl group, quinone group, lactone group and hydroxyl group, etc.) adsorbed on the surface of carbon black. The content of these groups represents the surface chemical properties of carbon black. It is related to the pH value of carbon black.
6. PH value index of pigment carbon black:
It represents the acidity and alkalinity of carbon black. Generally, furnace carbon black is alkaline (PH>7). Only after post-treatment carbon black its PH value is between 3--5 and its volatile content is higher.
7. Carbon black phase
Pigment carbon black is mainly divided into blue phase and yellow phase, which are mainly adjusted for the color of processed products. This index is very important when making high-end products.
8. Heating loss:
It is to measure the moisture content of carbon black at a certain temperature, which is related to the production environment of carbon black.
9. Density:
The weight per unit volume of carbon black is: (g/L), which indicates the size of the space occupied by various types of carbon black. The larger the granulation size, the greater the apparent density, and vice versa. The dispersibility of black (especially used in plastics and paint inks) has an influence.
10. Blackness:
The blackness of pigment carbon black is also an important indicator, which is usually expressed by the data measured by the "reflectance meter", and in most cases also reflects the original particle size of the pigment carbon black, which is a measure of the market price of the pigment carbon black. one of the important parameters.
Which indicators of pigment carbon black are important?
In fact, the pigment carbon black indicators listed above are relatively important, but they are also the most important. Specifically, the important indicators in pigment carbon black are: particle size, tinting strength, blackness, absorption value, and specific surface area. Of course, it is not to say that other pigment carbon black indicators are not important, but some pigment carbon blacks are used, and this is not very important.