Comparison of the advantages and disadvantages ...

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(1) White pigment

White pigments include Titanium Dioxide, lithopone, zinc white and antimony white. Hollow polymer microspheres are also good white pigments.

1. Titanium dioxide (TiO2)

A kind of most widely used white pigment, it is characterized by high whiteness, good coloring and covering power, excellent chemical stability, heat resistance and weather resistance. It can be divided into rutile type and anatase type.

1) Rutile (refractive index 2.76) has good weather resistance and no pulverization, which is suitable for outdoor coatings.

2) Anatase (refractive index 2.55) is inferior to rutile in stability, weatherability and pulverization, so it is suitable for indoor coatings.

2. Lithopone (lithopone, baso4zns)

Chemical property: alkali resistant, but decomposes in ACID , releasing H2S.
Strong covering power, easy to darken when exposed to light, poor weather resistance.

3. Zinc white (ZnO)

Advantages: good light resistance, heat resistance, weather resistance, no powder, can be used for outdoor paint.
Disadvantages: poor covering power. Lithopone ' lithopone ' titanium dioxide. It is alkaline and tends to thicken after paint making.
There is a kind of ZnO containing Pb, which is a mixture of ZnO and basic PbSO4. It has better antirust performance than ZnO and can be used in primer.
Nano ZnO can kill bacteria.

1. Antimony white (Sb2O3)
Covering power is second only to titanium dioxide, white appearance, better chalking property than lithopone, good heat resistance, used in fireproof paint. The mechanism is that antimony chloride reacts with chlorine containing Resin at high temperature to prevent fire spreading.

(2) Yellow pigment

1. Chrome Yellow (lead chrome yellow)
Its main component is PbCrO4 or PbCrO4 / xpbso4 mixed crystal. Due to different manufacturing conditions and compositions, the color is between lemon and orange.
Advantages: 1) good covering power and coloring power. With the increase of lead chromate content, the darker the color, the better the covering power. 2) It does not pulverize in the atmosphere.
Disadvantages: 1) under the action of light, the color will darken. 2) When exposed to H2S, it will react with PBS, black and toxic. 3) In case of alkali, it will change into orange chrome yellow, so it is not suitable to be shared with basic pigments. 4) It should be noted that lead compounds can accelerate the drying of dry oil.

2. Iron Oxide yellow (iron yellow, fe2o3h2o)
Good covering power, strong coloring power, light and alkali resistance. It is widely used in building materials.

3. Cadmium yellow (CDS)
The color is very bright, light resistant, heat-resistant, alkali resistant.
Disadvantages: 1) acid resistant; 2) easily powdered when exposed to moisture; 3) hiding power and coloring power are not as good as chrome yellow; 4) expensive.
It is suitable for making high temperature resistant coatings.

(3) Green pigment

1. Chrome oxide green (Cr2O3)
Features: insoluble in acid and alkali, resistant to SO2, H2S gas erosion. Good light and weather resistance, heat resistance, temperature resistance up to 700 '.
Disadvantages: the covering power is poor, the coloring power is worse, and it is not used much in the coating.
Suitable for chemical atmosphere and acid fog resistant coatings. High temperature paint, such as enamel.

2. Chrome Green [PbCrO4 · xpbso4 · yfenh4fe (CN) 6]
It is made of chrome yellow and iron blue. Good covering power and strong coloring power. Alkali resistant. It is widely used.

(4) Blue pigment

1. Iron blue [mxfey [Fe (CN) 6] 2 · nH2O, where M represents potassium or ammonium.
Features: strong coloring power, good light resistance and acid resistance.
Disadvantages: poor covering power, poor alkali resistance, not suitable for use with basic pigments. Hard texture, not easy to grind, surface treatment can improve the dispersion of grinding. Oil is easy to cause spontaneous combustion, especially in the process of slurry mixing and grinding. It is not safe until all particles are moistened by oil.

2. Ultramarine (3na2o · 3Al2O3 · 6sio2 · 2nas)

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Features: light resistant, heat-resistant, alkali resistant, can counteract the yellow phase in white paint and whiten.
Disadvantages: poor coloring power and covering power, easy to sink or float in the coating, so it is appropriate to make a separate color paste.

(5) Red pigment

1. Iron red (iron oxide red, Fe2O3)
Features: light, weather and chemical stability, low price.
It can be used for topcoat and primer in large quantity.

2. Cadmium red (3CDs · 2cdse)
Features: bright color, good coloring power, covering power, light resistance, weather resistance, heat resistance and sulfur resistance.
High price, only for high temperature resistant paint.

3. Molybdenum chrome red
Chemical composition: PbCrO4: 75 ~ 85%; PbMoO4: 10 ~ 15%; PbSO4: 3 ~ 10%
Characteristics: inorganic pigments are bright color, strong coloring power, good light resistance and heat resistance. It can be mixed with other Organic Pigments to obtain the red color of appropriate color.

(6) Black pigment

1. Carbon Black
Carbon black for coating is Pigment Carbon Black.
Features: high covering power, strong coloring power, the best light and weather resistant pigments, stable chemical properties, acid, alkali and high temperature resistance, so it is the most common black pigment.

2. Iron black (Fe3O4)
Features: strong coloring power, low covering power, stable to light and atmosphere, alkali resistance. It can enhance the mechanical strength of the coating film and has a certain anti rust ability. When the metal coating requires a certain mechanical strength, iron black can be used instead of carbon black.

(7) Metallic pigments

1. Aluminum powder (commonly known as silver powder)
1 ~ 2 μ m in thickness and 1 ~ 200 μ m in diameter.
Floating type: it has floatability after surface treatment. It can be arranged parallel to the surface in the film forming process, showing metallic luster and shielding effect. It is mainly used as the topcoat of anti-corrosion coatings.
Non floating type: high surface tension, can not float on the surface, but in the lower layer of the film can be parallel and directional arrangement, mainly used for metal flash paint.

2. Copper powder (commonly known as gold powder)

The flake powder made of zinc copper alloy can be made into gold powder of different colors with different proportion of zinc and copper, which is mainly used for decoration.

(8) organic pigments
Advantages: complete color; bright color; strong coloring power.
Disadvantages: poor covering power.

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The role of titanium dioxide (TiO2) and other white pigment technologies is essential in achieving exterior performance and improving a coating's opacity. As the market for long-lasting products continues to grow, so does the importance of selecting the right' grade of TiO2.

"TiO2 plays a complex role in paint durability," said Carlos Verdejo, global offerings manager, coatings, DuPont Titanium Technologies. "TiO2 itself is extremely durable, but the organic resin of the paint is not. One of the greatest threats to organic resin is UV light, which has enough energy to break chemical bonds in the resin polymer."

According to Verdejo, the primary role of TiO2 in most paints is beneficial, absorbing virtually all of the UV light that it encounters and protecting the underlying resin in the process. However, he pointed out that TiO2 is a photocatalyst, and some of the UV light energy is transformed into reactive chemical energy in the form of chemical radicals. "The best pigment is one that maximizes binder protections and minimizes photocatalytic activity," he added. "This is done by improving pigment dispersion in the final paint film and decreasing photocatalytic activity."

Kelly Green, vice president of market management, Tronox Inc., said durable grades of TiO2 assist in maintaining the integrity of exterior coatings and plastics by ensuring that the the TiO2 does not directly contribute to the degradation of the film and by shielding the interior portions of coatings or plastic from penetrating UV light.

"Coatings or plastic formulated with durable grades of TiO2 will have reduced levels of chalking and will have a better resistance to fading and gloss loss," said Green. "Today's durable grades of TiO2 provide outstanding combinations of durability and optical properties that enhance the paint formulator's tool kit by providing more choices and options to achieve their goals for their exterior paints."

Consumers and contractors have high expectations for their paint in terms of performance, coverage and appearance. TiO2 manufacturers work hard to meet these needs by developing new grades of TiO2.

"New grades are continually being designed to provide greater value to the coatings manufacturer and the coatings consumer," said Verdejo. "We are constantly gathering 'voice of the customer' data so that we can react quickly to market needs."

As a result of this customer feedback, DuPont recently made some enhancements to some of its older TiO2 grades. "Customers like the end-use performance of the original grade, but wanted it to be easier to disperse," said Verdejo. "The result is a grade that retains its original paint performance but allows the coatings producer to cut back on the amount of time and energy required to make the paint."

DuPont Titanium Technologies has recently launched two new products into the coatings market. TD- is designed as a multi-purpose grade with excellent dispersibility and durability. R902+ is an improved version of its R-902. The new product features increased dispersibility while retaining all other performance attributes.

According to Green, TiO2 provides the opacity or hiding power in nearly all paints. "Today's generation of TiO2 pigments do this with even better performance than ever before," he added. "Pigment manufacturers have developed products that provide greater opacity at lower loading levels giving even better performance, with less TiO2 than was previously required. This means that manufacturers have more flexibility in their formulations, which allows them to develop even more new effects in their coatings."

Tronox introduced a new dry hide grade in that now is commercially available. "We are working one-on-one with customers to formulate their products to use the new grade for architectural paints and anticipate increasing sales throughout this year," said Green. "We have new and improved products in the pipeline for nearly every major application and these grades are in various stages of development, from concept to laboratory development and preliminary plant trials."

Facing Rising Prices

Because of rising prices for titanium dioxide, coatings companies may look into using extender pigments to reduce overall costs. Titanium dioxide suppliers Coatings World spoke with cautioned that these cost cutting measures are not always worth it. Many times, especially where quality is concerned, you get what you pay for.

"It is fairly common practice for companies to use fillers of various types in an attempt to reduce TiO2 use and decrease their cost," said Green. "Use of these extenders, which include calcined clay, fine particle size CaCO3 and opaque polymer (polymer microvoid technology), can have a very negative impact on other performance properties important to the end-use paint customer, such as touch-up, wet hiding, stain resistance and scrub resistance."

Tronox works directly with customers to optimize their paint formulations to get the best possible performance from the TiO2 with minimal impact on other key performance properties, according to Green. "By getting the best possible performance from your TiO2, you can maintain the best overall combination of properties in the paint at a reasonable cost," he said. "For example, a slight change in dispersant level, dispersant type or other ingredients can significantly enhance the performance and efficiency of the TiO2, and thus eliminate the need to use lower-cost, lower-performance fillers."

"We believe all coatings markets should be using TiO2 as efficiently as possible, since no one benefits in the long term from waste due to inefficiency," said Verdejo. "That said, there are cases where coatings products are falling short of their hiding power potential. Sometimes reformulation is needed, particularly with respect to keeping the TiO2 particles well dispersed during pigment drying, when the liquid environment is changing rapidly and drastically. The key here is to alter the dispersant and other additives to create a robust dispersion."

In some cases, changing pigment grades can improve performance. New pigment grades are formulated to take maximum advantage of the chemistry of new dispersants and additives, according to Verdejo. "One area where I recommend caution is the notion that the use of certain extenders can greatly reduce the amount of TiO2 needed in a paint," he said. "Every few years we hear this claim from different extender manufacturers. It could well be that some cost improvement can be gained by partially substituting a modest amount of pigment with extender, but improvements at the levels suggested can only occur if the pigment is being used at a very low efficiency to begin with. We simply do not believe that this is the case for the vast majority of the coatings being made toady."

Maintaining open lines of communication to help their customers understand its role and select the best possible TiO2 pigment is key. '

"We have dedicated teams of sales, customer service and technical experts located around the world so we can assist customers where they operate," said Green. "Our customer service includes technical support, formulation optimization, product assistance, problem-solving, weathering facilities, process efficiency and other value-added joint projects. In addition, our research and development teams work closely with customers to enhance existing grades and develop new, high-performance pigment grades that meet customers' increasingly stringent technical requirements and address future needs."

"We always welcome interactions with customers," said Verdejo. "This is an essential way for us to anticipate needs in the industry and respond in a timely fashion. We do this through customer/marketing interactions, as well as those at a more technical level. We really learn a lot through these contacts, and our customers benefit as well."

Developing and growing their business in the Asia-Pacific region is also an important priority.

"The Asia-Pacific region is a key strategic growth area for Tronox," said Green. "This region is experiencing strong growth in excess of six percent and is projected to be the largest market for TiO2 within the next three to five years."

Tronox has a major presence in the region, supported by its operation located in Western Australia. This facility currently supplies the majority of its annual production to customers throughout the Pacific Rim. In addition, the company is increasing its sales and technical support services in the area.

"We project a strong demand for TiO2 as the Chinese economy grows," said Verdejo. "We currently serve Asia with our plant in Taiwan, and are in the early stages of building a world class plant in Dong Ying, in the PRC. This allows us to increase our supply of locally produced material in Asia and to position ourselves to grow with China."

BASF Offers Functional Black Pigments for Solar Heat Management

BASF has recently launched new NIR-transparent black pigments to reduce surface heat on construction elements. Lumogen Black FK and Lumogen Black FK functional black pigments have been designed to reduce the solar heat buildup of dark colored construction elements. According to the company, the solar heat buildup of dark colored, and even black construction elements can be cut in half when using NIR-transparent black pigments. BASF's newly developed functional black pigments offer exceptional transparency in the range of solar infrared radiation from 750 nm up to 2,500 nm. In addition, Lumogen black pigments offer excellent heat resistance, color strength and migration stability, as well as extreme resistance to chemical and physical effects, good dispersibility and insolubility in all common solvent.

Aside from solar heat management in construction, the coatings and printing ink industries are other potential applications for these cool black pigments.

If you want to learn more, please visit our website white pigment supplier.