Application of Pigment Carbon Black in Plastic Industry

Shenjia Hydraulic

Release time:

2022-04-21

Application of Pigment Carbon Black in Plastic Industry

1. Carbon black for coloring

Pigment carbon black can generally color plastics well. Pigment carbon black can be selected according to the coloring characteristics or physicochemical properties. The choice of coloring carbon black is basically determined by the blackness that the finished product must achieve. Very fine pigment carbon black can be used to complete the coloring with particularly high blackness requirements; PE garbage bags, plastic bags, cable materials and other products only need a moderate level of blackness, and carbon black varieties with lower specific surface area and higher structure can be used ;When plastic toning, the slight error in carbon black weighing and batching will lead to obvious color difference. Therefore, it is advisable to use low-pigment carbon black with larger particle size and poor tinting strength, so that the amount of carbon black can be slightly Larger, the weighing error is relatively small, and it has the advantages of better dispersion and lower price.

For gray plastics, the use of fine-grained pigment carbon black tends to produce a brownish gray, while the use of coarse-grained pigmented carbon black can produce a bluish gray.

Compared with other organic pigments, carbon black has better properties except that it is difficult to disperse. The scientific amount of carbon black can provide better antistatic or electrical conductivity.

Carbon black is basically non-toxic, but it is easy to fly and cause pollution, so it is often used in the plastics industry in the form of color masterbatch, which not only eliminates pollution but also improves the dispersion of carbon black in plastics.

As a pigment for plastics, carbon black is commonly used in powder and granular forms. Granular carbon black has less flying, but it is difficult to disperse, so powdered carbon black is used in plastic coloring.

Second, the application of UV protection

One of the uses of carbon black in the plastics industry is anti-ultraviolet light aging. Because carbon black has high light absorption, it can effectively prevent the photo-oxidative degradation of plastics due to sunlight. The functions of carbon black as a UV stabilizer in plastics include: converting light energy into heat energy; protecting the plastic surface from radiation of a certain wavelength; intercepting atomic groups to produce anti-aging effects, thereby preventing catalytic degradation. Ultraviolet rays are particularly harmful to polyolefins. Tests have shown that when the concentration of carbon black with a certain fineness is 2%, it can achieve perfect ultraviolet shielding effect.

The protective effect of carbon black on ultraviolet aging of plastics depends on the particle size, structure and surface chemistry of carbon black. Structure and Surface Chemistry.

When the particle size of carbon black is small, due to the increased surface area, its light absorption or shading ability increases, so the UV protection effect is enhanced, but the particle size is less than 20nm, its protective effect tends to the same level, the reason is that when the particle size is too small, the reverse Scattering is reduced, and light that continues forward threatens the stability of the polymer.

When the structure is lower, that is, when the aggregate size is smaller, the protective effect on the polymer will be enhanced due to the smaller geometric volume of the aggregate, which is also the reason why carbon black with lower structure is darker.

There are more oxygen-containing groups on the surface of carbon black, that is, when the volatile content is high, the genes generated when the polymer is decomposed can be eliminated, so the protective effect is also enhanced.

Third, the injection molding masterbatch is divided into advanced and ordinary types

High-grade masterbatch is mainly used in cosmetic packaging boxes, ABS for automobiles, high-grade PVC synthetic leather, housings for household appliances and other high-grade products. It requires uniform dispersion of pigments for color masterbatches, especially colorless spots and color spots for colored products. Pigment carbon black with small particle size and low structure should be used for carbon black, 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, and the higher the blackness. Bright.

Ordinary grade masterbatch is mainly used for PE garbage bags, cables, pipes and other products. Advanced film requires small pigment particles and uniform dispersion. There should be no color point greater than 0.6mm on the film. Ordinary film can choose larger particle size. , ordinary pigment carbon black with high structure, medium blackness and good dispersibility can be used.

2; Fiber masterbatch is mainly divided into polypropylene and polyester. Mainly used for chemical fiber yarn, carpet, non-woven fabric, etc. Carbon black is required to contain high purity, good dispersibility, high tinting strength, no impurities, and pigment particles less than 1um.

4. Carbon black dispersion equipment:

Carbon black shape Dispersion equipment

Powder three-roller, mill, disc disperser, extruder, high-speed mixer

Granular mixer, double roll mill, ball mill, sand mill.

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Shenjia Hydraulic

HUATAO GROUP