Technical parameters of purchasing equipment for pigment carbon black

Pigment carbon black used for coloring pigments in inks, paints, coatings, plastics, etc. According to the tint strength (or blackness) and particle size, it is generally divided into four kinds: high pigment carbon black, medium pigment carbon black, common pigment carbon black and low pigment carbon black. Mainly process are oil furnace and channel.

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Pigment carbon black generally offer good tint strength for plastic, according to the coloring characteristics or physicochemical properties of the selection of pigment carbon black, color with the selection of carbon black varieties are basically with the product blackness. Very fine pigment carbon black can be used to complete the blackness requirements of the particularly high color; PE garbage bags, plastic bags, cable materials and other products only need a medium level of blackness, can be used with a lower BET surface area, higher structure carbon black; In the process of plastic toning, the slight errors in the weighing and batching of carbon black will lead to obvious color difference. Therefore, it is advisable to use the low pigment carbon black with large particle size and low tint strength, so that the amount of carbon black can be slightly larger, the weighing error is relatively small, and has the advantages of better dispersion and lower price. For  gray plastics, the fine pigment carbon black often presents the grey color brown tone, while the coarse pigment carbon black can produce the grey color blue tone.

2

As a kind of black pigment, carbon black is widely used in the market:

Sealant classes: automobile sealant, construction sealant, ship building sealant, container sealant, special industrial sealant, waterproof sealant, hot melt adhesive, insulating glass sealant, Hollow glass butyl adhesive, Neutral mildew resistant silicone sealant, copper sealant, polyurethane sealant, neutral glass sealant, sealing strip, acidity silicone sealant used, butyl sealant.

Color paste : black synthetic leather color paste, printing paste, water-based color paste, paper paste, apple bag paste, PVC color paste, PU color pulp, oil color paste.

Masterbatch: shoes materials EVA foam, halogen-free cable material, plastic foam, blow film masterbatch, plastic masterbatch, PVC cable materials, PVC colloidal particles, polyester masterbatch, high gloss blue tone masterbatch, chemical fiber masterbatch,  short fiber masterbatch, rolling film, PE cable materials.

Ink: high pigment carbon black machine ink, high pigment carbon black ink, plastic bag ink, printing ink for plastic, plastic composite ink, plastic gravure ink, gravure ink, screen printing ink.

Coating: metal coating, plastic coating, automobile coating, marine coating.

Paints: automobile paint, high temperature resistance paint, epoxy floor paint, antiseptic paint, insulation paint, heat-resistant paint, alkyd paint, weather-resistant coating.

Specialty carbon black and building materials: high pigment carbon black environmental pencil lead, refractory matter, concrete foamed board, ultra-fine pigment carbon black, water soluble pigment carbon black, pigment carbon black green carbon black, pigment carbon black high temperature resistance carbon black, insulated pigment carbon black, high gloss blue pigment carbon black, leather, cement jointing , cosmetic mascara.

3

Compared with other organic pigments, carbon black has better properties except difficult disperse. Scientific carbon black match, can provide better antistatic or electrical conductivity. Carbon black is basically non-toxic, but easier to fly and pollution, so it is often used for plastic industry in the form of masterbatch, in the elimination of pollution while also improving the dispersion of carbon black in plastic. As a pigment for plastics, carbon black is commonly used in powder and granular forms. Granular carbon black is hard to fly, but dispersion is more difficult, so powder carbon black is used in plastic coloring.4

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Application of ultraviolet protection

One of the USES of carbon black in the plastic industry is anti-ultraviolet aging, because carbon black has high light absorption, so it can effectively prevent the plastic by sunlight and photooxidation degradation. Carbon black, as a uv stabilizer, plays a role in plastics: converting light energy into heat energy; Protect the plastic surface from radiation of a certain wavelength; The interception of the atomic group produces anti-aging effect, thus preventing catalytic degradation. Ultraviolet light is particularly harmful to polyolefin, and tests have shown that a perfect shielding effect can be achieved when the concentration of carbon black of a certain fineness is 2%.

Protective effect of carbon black on ultraviolet aging of plastics, depends on its particle size, structure and surface chemistry.

When the particle size of carbon black is small, the BET surface area increases and the absorption or shading capacity increases, so the UV protection effect is enhanced. However, the particle size is less than 20nm, and the protection effect tends to be the same. The reason is that when the particle size is too small, the reverse scattering decreases, and the light moving forward will threaten the stability of the polymer.

Low structure, small aggregate size, because aggregate geometry volume is small, will enhance the protection of the polymer, this is also why the lower structure carbon black is darker.

When the surface of carbon black contains more oxygen groups, that is, when the volatile content is high, it can eliminate the genes produced when the polymer is decomposed, so the protective effect is also enhanced

Injection masterbatches are divided into advanced and ordinary types

Advanced masterbatch is mainly used for cosmetic packaging boxes, automotive ABS, advanced PVC synthetic leather, household electrical shell and other advanced products. Masterbatch is required to disperse evenly with pigment, especially colorless points and spots of colored products. The pigment carbon black should be small particle size and low structure, because the blackness is mainly based on the absorption of light. The smaller the particle size, the higher the light absorption, the weaker the light reflection, the higher the blackness, and the product is generally black and shiny.

Ordinary masterbatch is mainly used for PE garbage bags, cables, pipes and other products. Advanced film requires small pigment particles and uniform dispersion, and no color point greater than 0.6mm should be found on the film. Ordinary film can be used with larger particle size, higher structure, medium blackness and better dispersion.

Fiber masterbatch is mainly divided into polypropylene, polyester. Mainly used for chemical fiber silk, carpets, non-woven cloth, etc. Carbon black is required to contain high purity, good dispersion, high coloring power, no impurities, pigment particles less than

5

Furnace carbon black

Carbon black is generated by incomplete combustion or pyrolysis of natural gas or high aromatic hydrocarbon oil in the reaction furnace. This kind of carbon black is called furnace black, which is the type of carbon black with the largest yield and the largest variety.The significant difference between furnace black and channel black and pyrolysis carbon black is that the degree of melting or coalescence of the particles can be adjusted according to different uses.Therefore, the furnace black with the same particle size range is divided into several derivatives with different structures.In addition, the oxygen content of the furnace black is usually lower than that of the channel black (less than 1%), and the surface is neutral or weakly alkaline.

The characteristics of furnace black production are that the fuel is burned in the reaction furnace to provide the heat required for the pyrolysis of the raw materials, and the combustion and pyrolysis processes occur simultaneously.According to the different forms of raw materials, furnace black production can be divided into gas furnace method and oil furnace method.The fuel used in the gas furnace method is natural gas.The fuel of oil furnace method can be natural gas, coke oven gas or liquid hydrocarbon, and the raw materials are selected from high aromatic hydrocarbon oils such as ethylene oil and anthracene oil.Reaction furnace is the core equipment in the process of furnace black production. It is necessary to use different size reaction furnaces for the production of different types of furnace black.The air and fuel are burned in the reaction furnace, and the raw materials are atomized and sprayed into the burning flame which generates carbon black through high-temperature pyrolysis.The carbon black is suspended in the burning gas to form flue gas. After being rapid cooling, the flue gas is sent to an air preheater,oil preheater for further cooling, and finally sent to a bag filter. The separated carbon black is sent to a granulator for granulation and then dried in a dryer.

Channel carbon black

The carbon black produced by using natural gas as the main raw material and channel steel as the flame contact surface is called channel black.Compared with furnace black and pyrolysis black, the particles are finer and the specific surface area is larger.At the same time, its surface is oxidized due to the specific production method, which contains more oxygen-containing functional groups and becomes acidic. The coalescence degree of these black carbon particles is low.Because it contains more oxygen-containing functional groups, it can delay the vulcanization rate of rubber, improve the weather resistance of polyolefin, and give ink good fluidity and printing performance.The hot cracking method takes natural gas, coke oven gas or heavy liquid hydrocarbon as raw materials, and generates carbon black through high-temperature pyrolysis under the condition of no oxygen and no flame, which is called pyrolysis black.It is the lowest specific surface area of carbon black varieties, basically exists as a single spherical particle, does not fuse or coalesce into aggregates, and its surface oxygen content is also very little (0.1% to 0.3%).

There are three main types of pyrolysis black: medium pyrolysis black, non-polluting medium pyrolysis black and fine pyrolysis black. The nitrogen adsorption specific surface area of the medium pyrolysis black is 6 to 10 m²/g, and the fine pyrolysis black is 10 to 15 m²/g.

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The use of pigment carbon black is primarily based on personal goods to choose, Pigment carbon black as pigment, is widely used in ink, coating, painting, color paste, sealant, plastic, ceramic, plastic, cable and other industrial production scope. Different categories of pigment carbon black functional demand is not the same, even in the same category, because the quality of the goods produced is not the same, the functional demand for materials will also have a greater difference.

The smaller the particle size of pigment carbon black, the higher the blackness. However, because the aggregation energy between particles is larger, so when the need for more energy in the slack, the selection of the appropriate slack agent and a better slack equipment is crucial. So when you’re producing something that doesn’t require a lot of blackness, don’t choose high pigment carbon black, to choose low oil absorption, medium black, better color power in the pigment carbon black to use, its price will not be very high, but also very good to meet the production demand.

In the medium pigment carbon black won’t make the blackness of high pigment carbon black and effect, in the demand for blackness of goods (such as advanced car paint), choose high blackness, through post-processing to improve the poor pigment carbon black goods, will reach outstanding effect.

Basic idea of choosing carbon black

The first thing users should consider before choosing carbon black is:What do you want to achieve with carbon black?Tinting, toning,uvioresistant or conductive?The most important thing is to communicate with the professional technical engineers of carbon black,and jointly evaluate the material system and choose the suitable carbon black variety.

Usually the situation is:

Tinting—-choose carbon black with high blackness and small particle size, but make sure that the carbon black is properly and completely dispersed, otherwise it will run counter to the original requirements.

Toning—-choose carbon black with low blackness, large particle size and easy dispersion.

Uv-resistant—-mainly used in plastics and rubber, choose carbon black with medium particle size and slightly higher structure, they have the best uv-resistant performance.

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The important significance of carbon black dispersion

Pigments must be dispersed into the micro-particle state in accordance with optical properties during application.Carbon black is one of the most difficult pigments to be dispersed among all pigments.Therefore, the dispersion of carbon black will directly affect the blackness, hue and covering ability of carbon black, and directly affect the user’s final use effect.

Common equipment of carbon black dispersion

Tyre of carbon black &Dispersion equipment

Powder: Three-roller machine/Centrifugal mills/Disk dispersion machine/screw extrude/high speed mixer

Granule: Internal mixer/Double roller machine/ball mil/Sand mill

The dispersion process of carbon black is mainly affected by three factors.

a）The essential characteristics of carbon black：The original particle size, structure and surface groups of carbon black will have a great impact on dispersion.Generally speaking, it is difficult to disperse carbon black with small original particle size, low structure and low volatile content. On the contrary,it is relatively easy.

b）User’s formula:The formulation, binder, solvent and resin properties of the carbon black users will significantly affect the final dispersion of carbon black, especially the choice of resin.

c）Dispersing equipment:The dispersion effect of different dispersing devices under the same conditions is completely different. Proper selection of dispersing equipment is a must that users must pay attention to.

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Several typical parameters of pigment carbon black

Blackness(reflectivity)–Carbon blackness is usually expressed by the data measured  “reflectance tester”. In most cases, it also reflects the original particle size of the carbon black and is one of the important parameters to measure the market price of the carbon black. The lower the reflectivity, the higher the blackness and the smaller the particle size. And vice versa.

Volatile component — the number of oxygen-containing groups carried on the surface of carbon black, which reflects the surface physical properties, electrochemical properties and application properties of carbon black, is also one of the important parameters to measure the market price of carbon black.

Structure — the structure of carbon black is the representative value of the degree of branch formed by the aggregate of carbon black particles, which represents the degree of interstitial space in the carbon black. It is usually expressed as oil absorption value (DBP absorption value).

Schematic diagram of the relationship between high and low structure carbon black and application performance

Appearance : black fine powder

Ash Content : ≤0.3%

BET Surface Area : 200~600m2/g

PH Value : 2-8

Heating Loss : ≤4%

Tinting strength : ≥120%