Learn the basics of masterbatch, this article is enough.

March 08, 2021

1. What is color masterbatch?

Color masterbatch, also known as color species, is a new type of colorant for polymer materials, also known as pigment preparations.
It is composed of three basic elements: pigments or dyes, carriers and additives. It is an aggregate obtained by uniformly attaching an ultra-constant amount of pigments or dyes to the resin. It can be called a pigment concentrate, so its coloring power is high. In the paint itself.
In short, the color masterbatch is an aggregate made by uniformly loading an ultra-constant amount of pigments or dyes in the resin.

2. What are the basic ingredients of color masterbatch?

The basic components of color masterbatch are:
1. Pigments or dyes
Pigments are divided into organic pigments and inorganic pigments.
Commonly used organic pigments are: phthalocyanine red, phthalocyanine blue, phthalocyanine green, light fast red, macromolecular red, macromolecular yellow, permanent yellow, permanent violet, azo red, etc.
Commonly used inorganic pigments are: cadmium red, cadmium yellow, titanium dioxide, carbon black, iron oxide red, iron oxide yellow and so on.
2. Carrier
The carrier is the matrix of the masterbatch. Special color masterbatches generally choose the same resin as the product resin as the carrier, and the compatibility of the two is the best, but at the same time, the fluidity of the carrier should also be considered.
3. Dispersant
Promote the uniform dispersion of the pigment and no longer agglomerate, the melting point of the dispersant should be lower than that of the resin, have good compatibility with the resin, and have a good affinity with the pigment. The most commonly used dispersants are: polyethylene low-molecular wax and stearate.
4. Additives
Such as flame-retardant, brightening, anti-bacterial, anti-static, anti-oxidation and other varieties, generally do not contain the above additives in the color masterbatch unless the customer requests it.

3. What kinds and grades of color masterbatches?

The classification methods of color masterbatches are commonly used as follows:
Classified by carrier: such as PE masterbatch, PP masterbatch, ABS masterbatch, PVC masterbatch, EVA masterbatch, etc.;
Classified by purpose: such as injection masterbatch, blow molding masterbatch, spinning masterbatch, etc.
Each species can be divided into different grades, such as:
1. Advanced injection color masterbatch: used in cosmetic packaging boxes, toys, electrical appliances and other advanced products.
2. Ordinary injection color masterbatch: used for general daily-use plastic products, industrial containers, etc.
3. Advanced blown film masterbatch: used for blow molding coloring of ultra-thin products.
4. Ordinary blown film masterbatch: used for blow molding and coloring of general packaging bags and woven bags.
5. Spinning masterbatch: used for spinning and coloring of textile fibers. The masterbatch has fine pigment particles, high concentration, strong coloring power, good heat resistance and light resistance.
6. Low-grade color masterbatch: used to manufacture low-grade products that do not require high color quality, such as trash cans, low-grade containers, etc.

7. Special masterbatch:
It is a color masterbatch made by selecting the same plastic as the carrier according to the plastic species designated by the user for the product. For example, PP masterbatch and ABS masterbatch use PP and ABS as the carrier respectively.
8. General masterbatch: also use a certain resin (usually low melting point PE) as a carrier, but it can be applied to the coloring of other resins besides its carrier resin.
Universal color masterbatch is relatively simple and convenient, but has many disadvantages. The heat-resistant grade of the special color masterbatch is generally compatible with the plastic used for the product, and it can be used with confidence under normal temperature. Only under the following conditions will cause different degrees of discoloration, one is that the temperature exceeds the normal range, and the other is that the downtime is too long.
9. Compared with granulation coloring, masterbatch coloring has the following advantages:
9.1 Coloring and product processing are completed at one time, avoiding the heating process of pelletizing and coloring on plastics, which is beneficial to protecting the quality of plastic products.
9.2 Minimize the production process of plastic products.
9.3 It can save a lot of power.

4. Why use color masterbatch?

The use of color masterbatch has the following advantages:
1. Make the pigment have better dispersibility in the product
The color masterbatch is an aggregate made by uniformly loading an ultra-constant amount of pigment in the resin.
In the production process of color masterbatch, the pigment must be refined to improve the dispersibility and tinting strength of the pigment. The carrier of the special color masterbatch is the same as the plastic of the product, and it has good matching. After heating and melting, the pigment particles can be well dispersed in the product plastic.
2. Conducive to maintaining the chemical stability of the pigment
If the pigment is used directly, the pigment will absorb water and oxidize due to direct contact with the air during storage and use. After the color masterbatch is made, the resin carrier separates the pigment from the air and moisture, which can make the quality of the pigment long-term change.
3. Ensure the stability of the product color
The masterbatch particles are similar to the resin particles, which are more convenient and accurate in metering. They will not stick to the container during mixing, and the mixing with the resin is more uniform. Therefore, the stability of the addition amount can be ensured to ensure the stability of the product color.
4. Protect the health of operators
The pigment is generally in powder form, which is easy to fly when added and mixed, and it will affect the health of the operator after being inhaled by the human body.
5. Keep the environment clean and not stain the utensils

6. The process is simple, the color is easy to change, saving time and raw materials
Because the pigment is in direct contact with the air during storage and use, it will absorb moisture, oxidize, agglomerate, etc., direct use will cause color spots on the surface of the plastic product, the hue is dark, the color is easy to fade, and cause it when mixing The dust is flying, which affects the health of the operators.
The color masterbatch undergoes mechanical processing during the production process to refine the pigments. The pigments are fully mixed with resin carriers and dispersants to isolate the pigments from air and moisture, thereby enhancing the weather resistance of the pigments and improving the The dispersibility and tinting strength of the pigment, the hue is bright. Since the color masterbatch is similar to the resin particle shape, it is more convenient and accurate in metering, and will not stick to the container during mixing, thus saving the time of cleaning the container and the machine and the raw materials used for the cleaning machine.

5. Precautions for using color masterbatch

1. How to use color masterbatch?
The use of color masterbatch is very simple. It only needs to be mixed with resin particles according to the specified ratio and mixed by hand.
Pay attention to the following issues in the operation of the equipment:
1.1 The mixing cavity of an injection molding machine or extruder generally has multiple temperature zones, among which the temperature near the blanking port should be slightly higher. This is to make the color masterbatch melt quickly after entering the mixing cavity and mix with the plastic resin as soon as possible Uniformity, which is conducive to the good dispersion of the color masterbatch in the product.
1.2 Properly apply back pressure to the injection molding machine, which can improve the mixing effect of the screw and facilitate the dispersion of pigments. The side effect of applying back pressure is to slow down the injection speed.
1.3 Increase the temperature of the die of the extruder appropriately to increase the brightness of the product.
2. How to determine the use ratio of color masterbatch?
The basis for determining the proportion of color masterbatch is to obtain a satisfactory coloring effect. As long as the surface tone of the product is uniform and there are no streaks and spots, it can be approved.
Take the seven-color deer mother as an example, the use ratio can be selected as follows:
1:100 Unless the mixing performance of the equipment is very good, uneven pigment dispersion is likely to occur. Generally, customers are not recommended to use this ratio.
However, due to price pressure, some customers particularly want to use this ratio of color masterbatches. For the sake of customers, they also produce more concentrated color masterbatches with such a low ratio, and the dispersibility of the pigments can generally meet the requirements.
1:50 Used for plastic products with general coloring requirements. PE and PP color masterbatches are mostly used in this ratio.
1:33–1:25 It is used for PO products with high coloring requirements, and ABS products with low coloring requirements or general.
1:20 Used for advanced plastic products, including PO, ABS, and can be widely used in injection molding, blow molding, spinning and other processes.
1:20 and above are generally used for coloring high-grade cosmetics containers, and mostly used for small injection molding machines.

3. How to calculate the cost of using color masterbatch?
The weight of the color masterbatch itself should be deducted when calculating the coloring cost of the masterbatch.
An example is as follows: 2 kg of color masterbatch is added to 100 kg of plastic resin. At this time, the total weight is 102 kg. Assuming that the price of resin is 10 yuan/kg and the price of color masterbatch is 20 yuan/kg, 102 kg of plastic products use color The increased costs for the mother are:
2 kg × (20 yuan/kg-10 yuan/kg)=20 yuan
Converted into the cost of using color masterbatch per 100 kilograms of plastic products:
20 yuan / 102 kg × 100 kg = 19.61 yuan
4. Will using color masterbatch increase product cost?
This is the case in most cases. However, in some cases, coloring with masterbatch is more economical than coloring with toner. The reason is that colorists can achieve the coloring effect of higher-priced pigments by combining several lower-priced pigments.
Also consider the following two phenomena:
(1) In many cases, the pigments selected by plastic manufacturers when matching colors with toners are not the most economical, and because they are not familiar with the pigments, it is very common to waste manpower and materials due to repeated trials when matching colors. The use of color masterbatch does not have this problem.
(2) The grades of products colored with color masterbatches and products colored with toner are completely different, and their prices are also higher. The higher prices are often higher than the increased cost of using color masterbatches, so On the contrary, color masterbatch can create "profit". From this perspective, in some cases, it is more economical to use masterbatch coloring than toner coloring.

5. Do the color masterbatches need to be dried before use?
Color masterbatches generally do not need to be dried and can be used directly. However, except for ABS and NY masterbatches, they should be dried according to conventional processes.
6. How long is the shelf life of color masterbatch?
Masterbatch can be stored for a long time. The pigment in the color masterbatch is dispersed and fixed in the carrier resin and is in a closed state, so its quality will not change even if it is stored for a long time. But it should be stored in a dry and cool environment.
7. Is it possible to use several different color masterbatches to formulate colors?
Several color masterbatches can be used to formulate specific colors for small-dosage customers. However, without the guidance of the company’s technical staff, customers should not make their own claims to use several color masterbatches together, let alone mixed use of color masterbatches produced by different companies. So as not to cause loss due to incompatibility.
8. Will the use of color masterbatch affect other properties of the product?
Some pigments have an impact on the flame retardant effect of the product. When used in flame-retardant products, it should be pointed out to the masterbatch manufacturer.
9. Does the mold affect the use of color masterbatch?
In order to fully display the coloring effect of the masterbatch, the mold must have corresponding quality, especially the surface must be very smooth.

Appendix: Properties of Pigments

1. Heat resistance
The temperature of PVC and PE pigments is 160-180 degrees Celsius;
The temperature of ABS and PS pigments is 250-280 degrees Celsius;
The temperature resistance of PP, PA, PET pigments is above 280 degrees;
Generally, the heat-resistant time of the pigment is required to be 4-10 minutes. Generally, the higher the use temperature, the shorter the heat-resistant time. Phthalocyanine blue pigment can withstand a temperature of 325 degrees Celsius and change color in 10 minutes.
2. Migration
The migration resistance of pigments refers to the fact that colored plastic products have long-term contact with other solid, liquid, gas and other substances or work in a certain environment, and they may have physical and chemical interactions with the above-mentioned substances, which is manifested as the pigment from the inside of the plastic. Migrate to the free surface of the product, or to the adjacent plastic or solvent.

Migration resistance rating standard
Level 1 Level 2 Level 3 Level 4 Level 5
Severe migration Significant migration With migration Minor migration No migration

3. Most inorganic pigments have good light resistance.
4. Weather resistance refers to the color stability of the pigment under natural conditions.
5. Titanium dioxide, also known as titanium dioxide, is divided into: anatase (A) titanium dioxide and rutile (R) titanium dioxide.
Titanium dioxide can improve hiding power, weather resistance, fading resistance, etc., and can effectively diffuse visible light to impart whiteness, brightness, and opacity to plastics.
When the concentration of titanium dioxide is low, the whiteness of PP increases with the increase of its content. When the concentration exceeds 1.5%, the whiteness no longer rises. From 1% to 8%, the whiteness only increases by 2.8%, which means that it exceeds a certain concentration. After the range, increasing the amount of titanium dioxide does not improve the whiteness. In order to further improve the whiteness, fluorescent whitening agent can be used, and only a small amount of fluorescent whitening agent can significantly improve the tinting power of titanium dioxide.
The concentration of titanium dioxide in PP\ABS is 1%; in PVC it ​​is 4%; as the amount of titanium dioxide increases, its hiding power gradually increases, and when the concentration is greater than 8%, it tends to balance.
In general, the finer the titanium dioxide particles, the higher the tinting power and the stronger the hiding power.
6. Cadmium yellow has strong tinting power, excellent light resistance and weather resistance, no migration and no bleeding.
This product can be used as a yellow colorant for plastics. It has bright colors, excellent light resistance, heat resistance, solvent resistance, water resistance and alkali resistance, but it is not acid resistant, coloring, and not too high in hiding power.
7. Ultramarine has the function of whitening and toning, it can remove the yellow shade in white products.