What is black?
Carbon black (also known as black carbon) is composed of hydrocarbons (mainly petroleum derivatives) after the quasi graphite structure material or thermal cracking formed approximately spherical colloidal particles of incomplete combustion, exists in the form of aggregates, apparent was pure black powder or granular. The product particle size, structure and surface activity according to the raw material and production process of different have the very big difference. Carbon black is not soluble in water, the pH of the points, combustion produces carbon dioxide. The main component of black carbon is carbon, hydrogen, oxygen, and contains trace amounts of sulfur, ash, tar and water.
What is the pigment carbon black?
As for carbon black pigment coating, ink and plastic called pigment carbon black, or pigment carbon black. Carbon black pigment used in paint, ink, plastic, and conductive, antistatic, UV shielding, prevent resin aging effect, therefore, people used in rubber carbon black, the black pigment broadly called special carbon black.
According to the statistics and forecast America NOTCH Advisory Group: the 2007 world carbon black production capacity of 10160000 tons, is expected in 2012 the world carbon black production capacity will be increased to 12000000 tons. Which was applied to tire and rubber industry rubber with carbon black accounted for more than 90% of total output, only about 10% of the carbon black as a pigment.
Characteristics of carbon black pigment
1 compared with other pigments, coloring carbon black have better and hiding power.
2 compared with other pigments, carbon black has very excellent heat resistance, chemical resistance and light resistance.
3 because of the carbon black particle diameter of only a few nanometers to tens of nanometers, the porosity is 90%, and inorganic material, so ordinary carbon black is very difficult to stably dispersed into the resin and organic system, and through strict control of carbon black pigment and special modified production process can well in coating, ink and plastic system embodied in the dispersion.
4 compared with the rubber carbon black, carbon black pigment of blackness and coloring power, surface activity, conductivity, ash, toluene transmittance, dispersion, liquidity and other quality indicators have more and more special requirements.
Technology of pigment carbon black (production methods)
According to the different production process, carbon black production methods are divided into furnace method, contact method (mainly for the slot method and non groove gas method) and the pyrolysis method three. Carbon black products Yongfeng company will use is the most important and most commonly used in the production process -- Oven method and prepared.
1 furnace is sealed in the reaction furnace, gaseous hydrocarbon (usually natural gas) or liquid hydrocarbon (usually coal tar, anthracene oil) as raw materials, for the right amount of air, the turbulent system closed is formed in the reaction furnace at high temperature by thermal oxidation and decomposition of the formation of carbon (carbon black properties the generated can be controlled through the quenching flame), and then cooled and filtered using a system separated from gas in carbon black production into. The characteristics of furnace method is to choose the scope of raw material is very wide, the properties of carbon black produced variety and diversity.
The use of gaseous hydrocarbon as the main raw material is called gas furnace method, using liquid hydrocarbon as the main raw material is called oil furnace method.
Compared with oil furnace method and other carbon black carbon black manufacturing method, can make the performance of different varieties, and has the technology adjustment means, unit capacity and high utilization rate of heat energy, raw material consumption and low comprehensive energy consumption and low cost, so it has become the dominant method for carbon black manufacturing, currently more than 95% of the world's oil furnace carbon black are used method. The.
2 slot method is solid hydrocarbon (crude anthracene) or liquid hydrocarbon (anthracene) gasifying kettle after gasification, and combustible gas (general use natural gas, also can use coke oven gas or water gas mixed) as raw material, by the network ring arranged into the natural ventilation of the fire room, through the porcelain fire in the channel mouth thousands of incomplete combustion, diffusion flame forming fishtail, channel the reduction layer and slow reciprocating motion of the contact, the CB cracking generation in a channel by channel surface cooling surface, process for producing carbon black collecting. The process for production of carbon black pigment yield is furnace is low, but the primary particle size is small, in the blackness and coloring power performance has better.
No groove gas mixing method is a process improvement method of gas production of carbon black carbon black gas method without fire real channel steel, carbon black flue gas suspension only collect in production. No slot compared gas mixing method and bath method, large production capacity, but due to the cancellation of the channel, to fire control as the slot method and roller method, the formation of carbon black was slightly lower than the slot method or roller method.
Carbon black powder and granular
Pigment carbon black has two existing forms of Physics: powdery and granular. The powder is easy to disperse but high transportation cost, is easy to pollute the environment. Granular acetylene black small dust, high density, more convenient transportation, but compared with the carbon black is difficult to disperse.
The existing state of carbon black aggregates
The performance of carbon black pigment
1 color strength
Also called tint strength. Is white or color pigment and carbon black mixed, coloring ability of carbon black. It is the mixture of carbon black light absorption increasing degree. It is usually a percentage of the form, can be measured by using the blackness reflectometer measurement on reduction of data derived from carbon black slurry. According to the industry standard for carbon black color paste operation, and titanium dioxide (or other white pigments such as Zinc Oxide) mixture and certain solvents. (ASTM D-3849 or GB/T 7050-2003 standard reference measure tinctorial power)
2 specific surface area
The specific surface area of carbon refers to the unit or the quality of carbon black particle surface area per unit volume of the sum, the unit is m2/g. The specific surface area and particle size is one of the basic properties of carbon black. In general, the carbon black surface is relatively smooth (such as rubber with carbon black) specific surface area and particle diameter is inverse, that is, the smaller the particle size is bigger than the surface area, and vice versa. So, such as the carbon black particle is assumed to be spherical, by particle size data calculation of specific surface area.
Carbon black surface area is divided into the external surface area (or smooth surface area), specific surface area (or pore specific surface area and total surface area). Total surface area is equal to the external surface area and total surface area than. A lot of determination of specific surface area, commonly used with nitrogen adsorption method (BET method), iodine absorption method, the method of CTAB (high molecular adsorption), t value method and electron microscopy etc..
The 3 DBP absorption value
Structure of carbon black can be used DBP (Dibutyl Phthlate) to measure the absorption value. According to the experience of low structure carbon black pigment, each 100g black DBP absorption value should be not more than 70ml; and the high structure carbon black pigment, value should be not less than 110ml per 100g black DBP absorption. In the structure of carbon black is somewhere in between. The structure has a substantial impact on the applications of carbon black pigment. (measurement of oil absorption value according to the ASTM D-2414 standard or GB/T 7046-2003)
The pH value of 4
On value of pH number and the surface functional groups. Functional groups on the surface of furnace black less, and there is a small amount of soluble salts, so black itself more neutral or alkaline. In order to improve the carbon black viscosity, stability and liquidity, some pigment carbon black by surface treatment to change the number of surface functional groups, which is acidic. (the pH value measurement according to GB/T 7045)