Currently, color masterbatch has a wide range of applications. The main service objects are the plastics industry, rubber industry and fiber industry and so on.
Color masterbatch classification
According to different uses, color masterbatch can be divided into injection masterbatch, blow molding masterbatch, spinning masterbatch, etc. Each variety can be divided into different levels.
Advanced injection color masterbatch is used for cosmetic packaging boxes, toys, electrical casings, and other advanced products.
Ordinary injection color masterbatch is used for general daily plastic products, industrial containers, etc.
Advanced blow molding color masterbatch is used for blow molding and coloring of ultra-thin products. Ordinary blow molding color masterbatch is used for blow molding and coloring of general packaging bags and woven bags. Spinning masterbatch is used for spinning and coloring of textile fibers with fine particles, high concentration, strong coloring power, good heat and light resistance.
Low-grade color masterbatch is used to manufacture low-grade products which do not require high color quality.
According to different carriers, it can be divided into PE, PP, PVC, PS, ABS, EVA, PC, PET, PEK, phenolic resin, epoxy resin, acrylic resin, unsaturated polyester resin, polyurethane, polyamide, fluorine resin color masterbatch, etc.
According to different functions, it can be divided into anti-static, flame retardant, anti-aging, anti-bacterial, whitening and brightening, transparency, weather resistance, extinction, pearlescence, imitation marble grain (flow grain), wood grain color masterbatch, etc.
According to user usage, it is divided into general color masterbatch and special color masterbatch. Low melting point PE masterbatch is often used as a general masterbatch for coloring other resins besides the carrier resin. The vast majority of legitimate color masterbatch enterprises internationally generally do not produce general color masterbatch which have a very narrow scope of application and poor technical indexes and economic benefits. General color masterbatch presents different colors in different plastics, resulting in poor predictability of coloring effects. General color masterbatch affects the strength of products which are prone to deformation and distortion, making it more obvious for engineering plastics. In order to be general-purpose, general color masterbatches choose higher heat-resistant grade pigments, which is costly and wasteful.
Special color masterbatch has significant advantages in product processing, such as high concentration, good dispersibility, and cleanliness. The heat resistance grade of special color masterbatch is generally compatible with the plastic used for products. It can be used without any worry under the normal temperature, and will only cause different degrees of discoloration if the temperature is out of the normal range and the downtime is too long.
It can also be divided into black, white, yellow, green, red, orange, brown, blue, silver, gold, purple, gray, pink masterbatches, etc. according to the different colors.
Basic components of color masterbatch
Pigments are the basic coloring components, and it is best to first undergo pre-treatment by covering the surface of their fine particles with resin to prevent mutual flocculation and make them easy to disperse. To achieve uniform coating and mixing, solvents that have affinity for pigments and can dissolve resins, such as o-dichlorobenzene, chlorobenzene, xylene, etc., are used. In the case of resin dissolution, disperse the pigment and then recover or remove the solvent.
The carrier is the matrix of the color master batch. At present, the special color masterbatch uses the same resin as the carrier which can ensure the compatibility between the color masterbatch and the colored resin, which is conducive to better dispersion of pigments. There are many types of carrier resins, including polyethylene, random polypropylene, poly (1-butene), and low relative molecular weight polypropylene, etc.
For polyolefin color masterbatch, LLDPE or LDPE with high melt index is generally selected as the carrier resin which has good processing flowability. It is blended with the colored resin to adjust the viscosity of the system, play a role in wetting and dispersing pigments, minimize the amount of dispersant, and even achieve good dispersion effect without dispersant, ensuring that the performance of the colored product does not decrease.
3. Dispersing agent
The dispersant wets and covers the pigment, promoting the uniform dispersion of the pigment in the carrier without agglomeration. Its melting point should be lower than that of the resin, and it has good compatibility with the resin and good affinity with the pigment. There are many types of dispersants available, such as low relative molecular weight polyethylene wax, polyester, stearate, white oil, oxidized low relative molecular weight polyethylene, etc.
In addition to coloring, the color masterbatch also adds flame retardants, antioxidants, antistatic agents, light stabilizers, etc. according to various user requirements, and has multiple functions.