The technical indicators of pigment carbon black include particle size, specific surface area, DBP absorption value, tinting strength, volatile content, PH value, hue, heating loss, density, blackness and other indicators. Each indicator has different meanings. The following are respectively. Introduce the significance of these technical indicators.
- The particle sizes of the various carbon blacks listed in the table represent the primary particle size of the carbon black, which is tested through an electron microscope and is the average value of a certain particle size. Pigment carbon black can be divided into high color carbon black, medium color carbon black and low color carbon black according to different particle sizes.
DBP absorption value (absorption value):
- It is the adsorption of carbon black using dibutyl phthalate (DBP). The amount of DBP consumed when the adsorption is balanced represents the size of the carbon black structure. A high adsorption value indicates a high carbon black structure, and vice versa.
Specific surface area
- It can be measured by BET (Brunauer-Enmet-Teller), the low-temperature nitrogen adsorption method. A simple and simple iodine adsorption method commonly used in the world can also be used. The measurement results represent the surface area per gram (㎡/g).
- The structure of pigment carbon black is a characteristic value of the degree of chain branches formed by the aggregates of carbon black particles. It represents the degree of voids inside the pigment carbon black . Usually expressed as oil absorption value (DBP absorption value).
- The blackness of pigment carbon black is usually expressed by the data measured by a “reflectivity meter”. In most cases, it also reflects the original particle size of the carbon black. It is one of the important parameters for measuring the market price of the carbon black pigment. The lower the reflectivity, the higher the blackness of the carbon black and the smaller the particle size. vice versa.
- It indicates the ability of pigment carbon black to dye white bodies. Generally, the tinting power is high and its hiding performance is good. The test method is carried out according to ASTM-3265.
- It represents the acidity and alkalinity of the pigment carbon blacks. Generally, furnace pigment carbon blacks are alkaline (PH>7). It’s just that after treatment, the pH value of carbon black is between 3-5 and the volatile content is higher.
- The number of oxygen-containing groups carried on the surface of pigment carbon blacks reflects the surface physical properties, electrochemical properties and application performance of the carbon black. It is also one of the important parameters for measuring the market price of carbon black pigment .
- It is to measure the moisture content of pigment carbon black at a certain temperature, which is related to the production environment of pigment carbon blacks.
- The weight of carbon black per unit volume is: (g/L), which represents the size of the space occupied by various types of carbon black. The greater the granulation size, the greater the apparent density, and vice versa. The granulation size has an impact on the carbon black. The dispersion of black (especially used in plastics and paints\inks) has an impact.