Color MasterBatch, also called color species. It is a new type of special colorant for polymer materials, also known as Pigment Preparation. Masterbatch is mainly used in plastics. Color masterbatch is composed of three basic elements: pigment or dye, carrier and additive. It is an aggregate made by evenly loading a super-normal amount of pigment into resin. It can be called pigment concentration (Pigment Concentration), so its The tinting power is higher than the pigment itself. During processing, a small amount of color masterbatch is mixed with uncolored resin to achieve a colored resin or product with a designed pigment concentration.

Basic ingredients

Pigments or dyes

Pigments are divided into organic pigments and inorganic pigments.

Commonly used organic pigments include: phthalocyanine red, phthalocyanine blue, phthalocyanine green, light-fast red, macromolecular red, macromolecular yellow, permanent yellow, permanent violet, azo red, etc. Commonly used inorganic pigments include: cadmium red, cadmium yellow, titanium dioxide, carbon black, iron oxide red, iron oxide yellow, etc.

Carrier

It is the matrix of masterbatch. For special masterbatch, the same resin as the product resin is generally selected as the carrier. The two have the best compatibility, but the fluidity of the carrier must also be considered.

Dispersant

To promote the uniform dispersion of pigments and no longer agglomeration, the dispersant should have a lower melting point than the resin, good compatibility with the resin, and good affinity with the pigment. The most commonly used dispersants are: polyethylene low molecular weight wax and stearate.

Additives

Such as flame retardant, brightening, antibacterial, antistatic, antioxidant and other varieties. Unless the customer requests it, the above additives are generally not included in the masterbatch.

Development history

Masterbatch is a new product for coloring plastics and fibers developed in the 1960s. It is a polymer composite made by loading a super-normal amount of pigment evenly into resin. Masterbatch is mainly composed of three parts: colorant, carrier and dispersant.

According to relevant information, the average annual growth rate of demand for color masterbatch in other countries in Asia is about 7%-9%, but the average annual growth rate of demand for color masterbatch in china is about 20%. China is expected to become the market with the fastest growing demand for masterbatch. Especially for colored and additive masterbatches, our country relies on imports. china has become the largest producer and consumer of masterbatch in Asia. There are 330 companies producing masterbatch in china, including 300 plastic-grade masterbatch factories and 30 fiber-grade masterbatch factories. These masterbatch manufacturers are mainly distributed in Fujian, Guangdong, Shandong, Zhejiang, Jiangsu, and Shanghai., Liaoning, Tianjin, Beijing, Hebei and other provinces and cities. There are nearly 50 companies with an annual production capacity of more than 1,000 tons of masterbatch in china. The national masterbatch production capacity is 300,000 tons per year. In 2001, the demand for masterbatch in china was less than 120,000 tons. Serious excess production capacity has led to a general under-operation in the domestic color masterbatch industry. In addition to factors such as the rapid growth of new production equipment and insufficient product orders, an important factor is that the domestic color masterbatch product structure is single and the varieties are incomplete. General-purpose products account for a large proportion. The proportion of high-concentration, ultra-high-concentration, multi-functional color masterbatch and color masterbatch for fine fiber is smaller. In contrast, countries with higher masterbatch technology have a complete range of raw materials such as pigments and dispersants, and have formed a serialized and specialized product structure. In terms of variety development, china’s masterbatch manufacturers have developed masterbatch for fiber, masterbatch for film, masterbatch for wire and cable, polyolefin masterbatch, PVC masterbatch, and masterbatch for injection molding products. Relevant experts believe that in the future, color masterbatch will develop in the direction of multi-functionality, high color content and high technology content. The development of color masterbatch is accompanied by the improvement of production technology.

Advantages

1. Make the pigment have better dispersion in the product. During the production process of the color masterbatch, the pigment must be refined to improve the dispersion and tinting power of the pigment. The carrier of the special color masterbatch is the same as the plastic type of the product, and has good matching. After heating and melting, the pigment particles can be well dispersed in the plastic product.

2. It is helpful to maintain the chemical stability of the pigment. If the pigment is used directly, the pigment will absorb water, oxidize and other phenomena due to direct contact with air during storage and use. After making the color masterbatch, the resin carrier will separate the pigment and air, Moisture isolation can keep the quality of the pigment unchanged for a long time.

3. Ensure the stability of the color of the product. The masterbatch particles are similar to the resin particles, making it more convenient and accurate to measure. They will not stick to the container when mixing, and the mixture with the resin is also relatively uniform. Therefore, the added amount can be ensured to be stable, thereby ensuring Product color stability.

4. Protect the operator’s health. Pigments are generally in powder form and are easy to fly when added and mixed. If inhaled by the human body, it will affect the health of the operator.

5. Keep the environment clean.

6. Easy to use.

Heat resistance

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 at normal temperatures. Different degrees of discoloration will only occur under the following circumstances: first, the temperature exceeds the normal range; second, the downtime is too long.

What is the difference between granulation coloring and masterbatch coloring?

Masterbatch coloring has the following advantages compared with granulation coloring:

1. Coloring and product processing are completed at one time, avoiding the heating process of plastics during granulation and coloring, which is beneficial to protecting the quality of plastic products.

2. Minimize the production process of plastic products.

3. Can save a lot of electricity

Will products colored with masterbatch not fade?

There is no absolutely non-fading product, and products colored with masterbatch may still fade, but the degree is different for different grades of products. Some are more obvious, while others are difficult to detect.

General color masterbatch and special color masterbatch

Special color masterbatch

It is a color masterbatch made according to the plastic type specified by the user and using the same plastic as the carrier. For example, PP masterbatch and ABS masterbatch use PP and ABS as carriers respectively.

Universal color masterbatch

It also uses a certain resin (often 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 it has many shortcomings. It is recommended that you choose special color masterbatch.

Why don’t many companies produce universal color masterbatch?

Most regular masterbatch companies in the world generally do not produce general-purpose masterbatch.

Universal color masterbatch has many shortcomings. In fact, the “universal” range of general masterbatch is very narrow, and the technical indicators and economic benefits are also poor. The specific manifestations are:

1. Poor predictability of coloring effects

Masterbatch is used for coloring. The pigments of general masterbatch will show different colors in different plastics, so the coloring effect is less predictable.

2. Affect other properties of plastic products

Especially affecting the strength, the product is easily deformed and twisted, which is more obvious for engineering plastics.

3.Higher cost

In order to be ‘universal’, general-purpose color masterbatches often use pigments with higher heat-resistant grades, resulting in waste.

In addition to coloring, can masterbatch also have functions such as flame retardant, brightening, antistatic, antioxidant, and UV resistance?

The color masterbatch can have some of these functions at the same time, if the factory requests this.

Sometimes, even though customers have not requested it, the color master company will also suggest users to add some additives according to the needs of the product, such as adding certain additives to the color masterbatch, such as brighteners. Of course, this will increase the cost of the product.

Things to note

1. How to use masterbatch?

The use of color masterbatch is very simple. You only need to mix it with resin particles according to the specified ratio and mix it by hand.

The following issues should be paid attention to during the operation of the equipment:

1.1. The mixing chamber of an injection molding machine or extruder generally has multiple temperature zones. The temperature of the section near the blanking port should be slightly higher. This is to make the color masterbatch melt quickly after entering the mixing chamber and mix with the plastic resin as quickly as possible. Mix evenly so that the masterbatch pigments are well dispersed in the product.

1.2. Appropriately 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. Appropriately increasing the die temperature of the extruder can increase the brightness of the product.

2. How to determine the proportion of color masterbatch used?

The basis for determining the proportion of color masterbatch used is to obtain a satisfactory coloring effect. As long as the surface tone of the product is uniform and there are no streaks or spots, it can be approved. The usage ratio of color masterbatch can be selected as follows:

1:100 Unless the mixing performance of the equipment is very good, uneven pigment dispersion may easily occur. It is generally not recommended for customers to use this ratio.

However, due to price pressure, some customers particularly hope to use this proportion of color masterbatch. For the sake of customers, more concentrated color masterbatch with such a low proportion is produced, and the dispersion of pigments can generally meet the requirements.

1:50 is used for plastic products with general coloring requirements. PE and PP color masterbatches mostly use this ratio.

1:33–1:25 is used for PO products with higher coloring requirements, and ABS products with lower or general coloring requirements.

1:20 is used for high-end plastic products, including PO and ABS, and can be widely used in injection molding, blow molding, spinning and other processes

1:20 or above is generally used for coloring high-end cosmetic containers, and is often used in small injection molding machines.

3. How to calculate the cost of using masterbatch?

When calculating the cost of masterbatch coloring, the weight of the masterbatch itself should be deducted.

For example: add 2 kilograms of color masterbatch to 100 kilograms of plastic resin. At this time, the total weight is already 102 kilograms. Assume that the resin price is 10 rmb/kg and the color masterbatch price is 20 rmb/kg.

Then the increased cost due to the use of color masterbatch in 102 kilograms of plastic products is:

2 kg × (20 rmb/kg-10 rmb/kg) = 20 rmb

Converted into the increased cost due to the use of color masterbatch per 100 kilograms of plastic products:

20 rmb/102 kg × 100 kg = 19.61 rmb

4. Will using masterbatch increase product cost?

In most cases this is the case. But in some cases, using masterbatch coloring is more economical than using toner coloring, because colorists can achieve the coloring effect of higher-priced pigments through a combination of several lower-priced pigments.

There are also two phenomena to consider:

1. In many cases, the pigments selected by plastic product manufacturers when using toners for color matching are not the most economical. Due to lack of familiarity with the pigments, repeated trials during color matching are very common, resulting in a waste of manpower and materials. This problem does not exist when using masterbatch.

2. The grades of products colored with color masterbatch are completely different from those colored with color powder, and their selling price is also higher. The higher selling price is often higher than the increased cost of using color masterbatch, so color On the contrary, the mother can create “profit”. From this perspective, in some cases, it is more “economical” to use masterbatch coloring than toner coloring.

5. Does the color masterbatch need to be dried before use?

Masterbatch generally does not need to be dried and can be used directly. However, except for ABS and NY masterbatch, they should be dried according to conventional processes.

What is the shelf life of masterbatch?

Masterbatch can be stored for a long time.

The pigments in the masterbatch are dispersed and fixed in the carrier resin and are in a closed state. Their quality will not change even if they are stored for a long time. But should be stored in a dry, cool environment

6. Can several different color masterbatch be used to prepare the color?

Generally, companies often use several color masterbatches to prepare specific colors for small-volume customers. However, without the guidance of the company’s technical personnel, customers are not allowed to use several color masterbatches together on their own initiative, let alone mixed use of color masterbatch produced by different companies, to avoid incompatibility and losses.

7. Will the use of masterbatch affect other properties of the product?

Some pigments have an impact on the flame retardant effect of products. When used in flame retardant products, please contact the masterbatch manufacturer.

8. Does the mold affect the use of 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.

Common defects

1. Under sunlight, there are striped pigment bands in the product.

This issue needs to be considered from two aspects: plastic physical and mechanical properties and plastic molding process:

1.1 The temperature of the injection molding equipment is not well controlled, and the masterbatch cannot be fully mixed with the resin after entering the mixing chamber.

1.2 The injection molding machine does not add a certain amount of back pressure, and the mixing effect of the screw is not good.

1.3 The dispersion of the color masterbatch is not good or the resin plasticization is not good.

In terms of process, the following adjustments can be made: 1. Slightly increase the temperature of the mixing cavity near the blanking port. 2. Apply a certain back pressure to the injection molding machine.

If it still does not improve after the above debugging, it may be a dispersion or matching problem with the masterbatch and resin, and you should contact the masterbatch manufacturer for resolution.

2. After using a certain color masterbatch, the product appears to be more likely to break.

This may be due to poor diffusion and miscibility caused by the poor quality of the dispersants or additives selected by the manufacturer, which affects the physical and mechanical properties of the product.

3. After using the masterbatch according to the proportion in the instruction manual, the color is too dark (too light)

Although this question is simple, there are many possibilities, specifically:

3.1. The color masterbatch has not been carefully tested, and the pigment is too little or too much.

3.2. Inaccurate measurement during use, and a large number of some enterprises, especially small and medium-sized enterprises, use arbitrary measurement.

3.3. There is a problem with the matching of color masterbatch and resin. This may be due to improper selection of the color masterbatch carrier, or the manufacturer may change the resin variety at will.

3.4. The machine temperature is improper and the color masterbatch stays in the machine for too long.

Processing procedures: First check whether the resin type matches the masterbatch and whether the measurement is accurate. Secondly, adjust the machine temperature or speed. If there are still problems, please contact the masterbatch manufacturer.

4. With the same color masterbatch, resin and formula, why do the products injected by different injection molding machines have different colors?

This is often caused by the injection molding machine. Different injection molding machines have different mechanical conditions due to different manufacturing, usage time or maintenance conditions, especially the difference in the close contact between the heating element and the barrel, resulting in different dispersion states of the color masterbatch in the barrel. As mentioned above, phenomenon will appear.

5. After changing to another brand of resin, the color of the same masterbatch and formula has changed. Why is this?

The density and melt index of different grades of resin will be different, so the performance of the resin will be different, and the compatibility with the masterbatch will also be different, resulting in color changes. Generally speaking, as long as the density and melt index are the same If it is large, the color difference will not be too big. The color can be corrected by adjusting the amount of color masterbatch.

6. Will pigment migration of masterbatch during storage affect the quality of the product?

Some color masterbatches have a high pigment (or dye) content, in which case migration is normal. Especially when dye is added to the masterbatch, serious migration will occur. But this does not affect the quality of the product, because after the masterbatch is injected into the product, the pigment is at a normal color concentration in the product.

7. Why do some injection products have poor gloss?

There are many possibilities:

7.1. The nozzle temperature of the injection molding machine is too low

7.2. The mold finish of the injection molding machine is not good.

7.3. Product molding cycle is too long

7.4. The color masterbatch contains too much titanium dioxide.

7.5. The dispersion of color masterbatch is not good

8. After a period of time, some plastic products will fade.

The basic pigments used by the manufacturer are of poor quality and drift occurs.

9. Why is ABS masterbatch so prone to color differences?

Different brands of ABS produced in various countries have large color differences. Even for the same brand of ABS, there may be color differences in each batch. Of course, color differences will also occur after using masterbatch coloring. This is caused by the characteristics of ABS, and there is no complete solution internationally. However, this color difference is generally not serious.

Users must pay attention to this characteristic of ABS when using ABS masterbatch.

Production process

Requirements for colorants used in masterbatch

When using colorants for masterbatch, attention must be paid to the matching relationship between the colorants, plastic raw materials, and additives. The key points for selection are as follows.

(1) The pigment cannot react with resin and various additives, and has strong solvent resistance, low migration, and good heat resistance. In other words, masterbatch cannot participate in various chemical reactions. For example, carbon black can control the curing reaction of polyester plastic, so carbon black materials cannot be added to polyester.

Since the molding and processing temperature of plastic products is relatively high, the color material should not decompose and change color under the molding heating temperature. Generally, inorganic pigments have better heat resistance, while organic pigments and dyes have poorer heat resistance. This should be taken into consideration when selecting pigment types.

(2) The dispersion and tinting power of the colorant should be good. When the colorant is unevenly dispersed, it will affect the appearance and performance of the product; when the colorant has poor tinting strength, it will increase the amount of colorant and increase the material cost. The same colorant has different dispersibility and tinting power in different resins, so you should pay attention to this when selecting colorants.

The particle size of the colorant is also related to the dispersion. The smaller the particle size of the colorant, the better the dispersion and the stronger the tinting power.

(3) Other properties of colorants should be understood. For example, for plastic products used in food and children’s toys, colorants are required to be non-toxic; for plastic products used in electrical appliances, colorants with good electrical insulation should be selected; For plastic products used outdoors, colorants with good weather aging resistance should be selected.

Masterbatch production process flow

Masterbatch production process requirements are very strict, and wet processes are generally used. Masterbatch is made by water phase grinding, phase transfer, water washing, drying and granulation. Only in this way can product quality be guaranteed.

In addition, while the pigment is being ground, a series of tests should also be carried out, such as measuring the fineness of the sanding slurry, measuring the diffusion performance of the sanding slurry, measuring the solid content of the sanding slurry, and measuring the fineness of the color paste.

There are four methods in the process flow of color masterbatch production:

(1) Ink method: As the name suggests, it is a production method that uses ink paste in the production of masterbatch, that is, through three-roller grinding, a low-molecular protective layer is coated on the surface of the pigment. The ground fine color paste is mixed with the carrier resin, then plasticized through a two-roller mill (also called a two-roller open mill), and finally granulated through a single-screw or twin-screw extruder.

The process is as follows:

Ingredients are stirred for coarse color slurry, three-roller grinding for fine color slurry, two-roller plasticization, extrusion and granulation.

(2) Flushing method: The pigment, water and dispersant are sanded to make the pigment particles less than 1 μm, and the pigment is transferred into the oil phase through the phase transfer method, and then dried to obtain the color masterbatch. Organic solvents and corresponding solvent recovery devices are required for phase transfer. The process is as follows:

The fine color slurry is washed, evaporated, and the concentrated material is dried, added with a carrier, extruded and granulated.

(3) Kneading method: After mixing the pigment and the oily carrier, the pigment is washed from the water phase into the oil phase by kneading, taking advantage of the lipophilicity of the pigment. At the same time, the surface of the pigment is coated by an oily carrier to stabilize the pigment dispersion and prevent pigment aggregation.

(4) Metal soap method: The pigment is ground to a particle size of about 1 μm, and soap is added at a certain temperature so that the surface layer of each pigment particle is evenly moistened by the soap to form a layer of saponified liquid. When the metal After the salt solution is added, it chemically reacts with the saponification layer on the surface of the pigment to form a protective layer of metal soap (magnesium stearate). This prevents the ground pigment particles from causing flocculation and protects certain fine particles. Spend.

Precautions when using masterbatch

(1) Color masterbatch will absorb moisture after being stored for a period of time, especially PET, ABS, PA, PC, etc., so it must be dried according to the same process as natural color masterbatch and meet the moisture content requirements.

(2) You must be very careful when using color masterbatch to achieve the desired color, as color difference and changes in color and light often occur.

(3) Masterbatch will react with other additives, so be careful when using it.

(4) Attention should be paid to the selection of the dilution ratio of the color masterbatch. Choosing a high dilution ratio will result in lower production costs, but it will also be limited by processing equipment.

Masterbatch classification

The commonly used classification methods for color masterbatch are as follows:

Classified by carrier: such as PE masterbatch, PP masterbatch, ABS masterbatch, PVC masterbatch, EVA masterbatch, etc.

Classified by use: such as injection masterbatch, blow molding masterbatch, spinning masterbatch, etc. Each variety can be divided into different grades, such as:

1. Advanced injection masterbatch

Used in cosmetic packaging boxes, toys, electrical casings and other high-end products.

2. Ordinary injection masterbatch

Used for general daily 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 textile fibers. The masterbatch pigment has fine particles, high concentration, strong tinting power, and good heat resistance and light resistance.

6. Low-grade masterbatch

Used to manufacture low-level products that do not have high requirements on color quality, such as trash cans, low-level containers, etc.

Other

Color masterbatch: Jincheng masterbatch group produces black masterbatch, white masterbatch, red masterbatch, blue masterbatch, yellow masterbatch, green masterbatch, purple masterbatch, silver masterbatch, golden masterbatch

Titanium dioxide: General agent of Jincheng Masterbatch Group; Spain’s Meililian titanium dioxide R-CL69, R-CL595, Britain’s R-TC30, R-FC5, R-PP25, and the United States DuPont titanium dioxide R-902, R-900, R- 706, R-103, R-104, R-105, Japanese titanium dioxide R-930, Panzhihua Iron and Steel Co., Ltd. R-248, Panzhihua Iron and Steel Co., Ltd. R-258, Lomon R-996, etc. imported domestic titanium dioxide

General agent of Carbon Black Jincheng Masterbatch Group; Hualing brand N330, N220, N326, environmentally friendly high-pigment carbon black LT-1, LT-2, LT-3, LT-4, etc., and imported carbon black

Pigment additives: British Ultramarine 5008, British Ultramarine 5006, oily black, titanium blue, titanium green, fluorescent pigments, luminous powder, 2N blue, and other domestic pigments, imported pigments, antioxidants, anti-UV agents, foaming agents, defoaming agent, opening agent, antistatic agent, steel strengthening agent, whitening agent, toughening agent, fire retardant powder, Malaysian EBS, Japan EB-FF, diffusion oil, diffusion powder, filling, recycled materials and other domestic additives, Imported additives.

Application scope

It is widely used in polyethylene, polypropylene, polystyrene, ABS, nylon, PC, PMMA, PET and other resins to produce colorful fibers, clothing, daily plastics, wires and cables, household appliances, agricultural films, automobiles Accessories, health care equipment and other products.

Appendix: Performance of Pigments

1. Heat resistance: PVC and PE pigments have a temperature resistance of 160-180 degrees Celsius. ABS and PS pigments have a temperature resistance of 250-280 degrees Celsius. PP, PA and PET pigments have a temperature resistance of 280 degrees and above. Generally, the heat resistance time of the pigments is 4-10. minutes, generally, the higher the use temperature, the shorter the heat resistance time.

Phthalocyanine blue pigment has a temperature resistance of 325 degrees Celsius and changes color in 10 minutes.

2. The migration resistance of migratory pigments means that when colored plastic products are in long-term contact with other solid, liquid, gas, etc. substances or work in a specific environment, they may have physical and chemical interactions with the above substances, which is manifested as Pigments migrate from within the plastic onto the free surface of the article, or into adjacent plastics or solvents. Migration resistance rating standards: Level 1, Level 2, Level 3, Level 4, Level 5, Severe migration, Significant migration, Slight migration, No migration. 3. Most inorganic pigments have good light resistance.

4. Weather resistance refers to the color stability of pigments under natural conditions.

5. Titanium dioxide is divided into: anatase type (A) titanium dioxide rutile type (R) titanium dioxide. Titanium dioxide can improve hiding power, weather resistance, fading resistance, etc. ~~~ When the concentration of titanium dioxide is low, the whiteness of PP changes with the The increase rate of its content increases. When the concentration exceeds 1.5%, the whiteness no longer increases. From 1% to 8%, the whiteness increases by 2.8%. This shows that after exceeding a certain concentration range, increasing the dosage of titanium dioxide does not improve the whiteness. Spend. In order to further improve the whiteness, fluorescent whitening agents can be used. Only a small amount of fluorescent whitening agents can significantly improve the tinting power of titanium dioxide. Titanium dioxide, alias: titanium dioxide, titanium dioxide can effectively scatter visible light to plastics to impart whiteness, brightness, and opacity. The concentration of titanium dioxide in PP\ABS is 1%; in PVC it ​​is 4%; as the dosage of titanium dioxide increases, its hiding power gradually increases, and tends to balance when the concentration is greater than 8%. Generally speaking, 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, and does not migrate or bleed (toxic pigments). This product can be used as a yellow colorant for plastics. It has bright color, excellent light resistance, heat resistance, solvent resistance, water resistance and alkali resistance, but it is not acid resistant, coloring and covering power is not very high.

7. Ultramarine blue has the function of whitening and toning. It can remove the yellow light in white products.