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Inorganic Pigments for Paints, Coatings and Inks

Inorganic pigments are undoubtedly the go-to pigment market for brighter, stable and long lasting pigments.

Want to know more about inorganic pigments?

Find the list of inorganic pigment families discussed in detail here and hence chose the ideal pigment for your paint/coating/ink formulation.

Families of Inorganic Pigments

Inorganic Pigments for Inks and CoatingsThe use of inorganic pigments dates back to the early cave paintings that are 30,000 years old. Although they occur naturally, for the manufacturing of paint they usually require modification. All white pigments are inorganic and a wide range of colored pigments is also available.

Enlighten your knowledge in colored pigments given in detail below or simply click the specific pigment of your choice

Inorganic Red Pigments

Lead chromate Pigment Red 103
CI 77601
  • Good opacity
  • Excellent Light fastness & weatherability
  • Low acids resistance
  • Excellent bases resistance
These pigments are relatively cheap
Lead Molybdate
Pigment Red 104
CI 77605
  • Good opacity durability and heat stability
  • Moderate alkali resistance
  • Excellent solvent resistance
Cadmium red
Pigment Red 108
CI 77202
  • Moderate tinctorial strength
  • Good light fastness
  • Bright color  Excellent  opacity and solvent resistance
  • Bad acid stability
Relatively expensive
Red iron oxide
Pigment Red 101 (synthetic) & Pigment Red 102 (natural)
  • Excellent heat stability, solvent resistance and chemical stability
  • Low tinctorial strength
Economical to use

Inorganic Blue Pigments

The blue pigment range is dominated by one chemical type - Phthalocyanine. It is considered as the ideal pigment to impart blue color in paints and coatings.

Other blue pigments include:

  1. Indanthrone which is used for particular high quality applications
  2. Ultramarine and Prussian blue are two inorganic pigments occasionally used

The printing ink industry uses some cationic toners (phospho tungsto molybdic acid, ferrocyanide and alkali blue pigments), but their poor solvent and chemical resistance coupled with poor light fastness means they have virtually no use in paint.

Prussian blue Pigment Blue 27
CI 77510 / 77520
  • Excellent solvent resistance and good heat stability
  • Excellent light fastness, poor alkali stability. It gives an intense, strong color
  • Because of its hygroscopic nature (approx. 4% of water), Prussian blue is difficult to wet
  • This pigment is flammable. On burning, it produces HCN, NH3, CO, and CO2 gases
This pigment is mainly used in printing inks. It can also be used in industrial coatings and in automotive paints
Pigment Blue 29
CI 77007
  • Excellent solvent resistance and heat stability
  • Good alkali stability and light fastness
  • Poor stability to acids
Cobalt blue Pigment Blue 28
CI 77346
Pigment Blue 36 & Pigment Green 50
  • Excellent chemical and heat stability
  • Good solvent resistance
Used in powder coatings, silicone paints and inks

Inorganic Green Pigments

The green spectrum is dominated by copper phthalocyanine pigments. The common method to reach green is by mixing yellows and blues, the desired brightness and economics being the two main factors determining the best approach. Inorganic pigments play a comparatively insignificant role.

Chrome green Pigment Green 15 Obtained by co-precipitation or dry blending of Chrome Yellow and Prussian Blue
  • These pigments have the same properties as the pigments used for their preparation
  • They have a tendency to float or flood because they wet out at different rates
Chromium oxide green Pigment Green 17
CI 77288
  • Excellent solvent resistance, heat- & chemical stability, light fastness & weatherability
  • Good opacity
  • Low tinctorial strength
Hydrated chromium oxide Pigment Green 18
CI 77289
Cr2O(OH)4 - Similar in chemistry to chromium oxide
  • Excellent alkalis resistance, light fastness & weatherability
  • Low acids resistance & heat stability

Inorganic Black Pigments

Black pigments are characterized by their origin:

  • Organic blacks
  • Inorganic blacks: iron oxides, graphite
  • Vegetable blacks: peach, charcoal, vine
  • Animal blacks: bones, ivory

Organic or inorganic blacks are the most important groups, as well as carbon black which are the most common black pigment.

Black Iron Oxide Pigment
Black 11
  • Relatively cheap and inert pigment
  • Excellent solvent- & chemical resistance and light fastness
  • Excellent durability and weatherability
  • Low tinctorial strength — An advantage when used as a tinter, as it allows more control
  • Low oil absorption as compared to other black pigments
  • Mainly used in applications where the tendency of carbon black to float cannot be tolerated (for example in grey tones in combination with titanium dioxide)
Black Micaceous Iron Oxide Not listed
  • Inert
  • Greyish appearance and a shiny surface
  • Capacity to absorb UV radiation also protects the polymers when used as binders
  • Plate-like structure prevents the passage of oxygen and moisture
  • Should not be over-dispersed because the platelets can be damaged and rendered ineffective
  • Used in heavy-duty coatings to protect structural steelwork

Inorganic Brown Pigments

Iron oxide is the most important brown pigment, but a few organic pigments are used for specialty applications.

Iron Oxide Brown Pigment Brown
6, 7
  • The natural form of Brown Iron Oxide is called burnt sienna or burnt umber
  • Pigments are made from naturally occurring ores that are then heated, various shades depend on the impurities, especially MnO content
  • Has low tinting strength but is not opaque
  • Imparts a rich brown color and give excellent fastness properties
  • Synthetic brown iron oxides are not used in paint formulations, as similar shades can be obtained using mixtures of cheaper pigments
  • Burnt sienna and burnt umber have become well known due to their use for artists' colors. But they can be used in commercial paints
Metal complex brown Pigment
Brown 33
  • It has a spinel structure
  • Excellent light fastness and high heat stability
  • Mainly used in ceramics
  • Can be used in coil coatings, where its high heat stability and excellent fastness properties make it a useful pigment

White Pigments for Coatings and Inks

All white pigments are inorganic. The more used white pigment is Titanium Dioxide.

Titanium Dioxide became the dominant white pigment after the Second World War. White pigments are compared by their reducing power. This corresponds to the amount of white pigment needed to produce an equal depth of shade when used with a standard amount of colored pigment.

Titanium Dioxide Pigment White 6
CI 77891
  • Exists in three crystal forms: Brookite - Not used as a pigment; Anatase - Used occasionally; Rutile - The most commonly used crystal form
  • High resistance to most chemicals, organic solvents and hea
  • High refractive index
  • Good durability and resistance to industrial atmospheres
  • But, photoreactivity reduces the light fastness of some colored pigments and nearly all organic pigments
  • Has favorable physiological properties due to its inert composition
  • suitable for use in food packaging, toys, and other sensitive applications, provided that it meets purity criteria
  • Can be used in all building and industry coating formulations
White Lead Pigment White 1
  • Formula: 2PbCO3Pb(OH)2
  • Reacts with acidic binders to provide tough and durable elastic films
  • Reacts with sulphurous gases in industrial atmospheres and turns black
  • Use of white lead is severely restricted due to concerns regarding the toxicity of lead compounds
Zinc Oxide Pigment White 4
CI 77947
  • An amphoteric oxide
  • Good white color when it has a high purity (> 99.5%)
  • Hexagonal crystal structure has empty spaces due to the big difference in size between zinc and oxygen atoms resulting in semi-conductor properties
  • In a binder with a low acid index, it produces zinc soaps which improve the wet out of the pigment and make the dispersion easier
  • In a binder with a high acid index, it can cause severe thickening
  • Improves the viscosity of the paint and reduces the sedimentation
  • Excellent bases resistance
  • Can be used as additional pigment with TiO2 to improve chalking resistance, or with lithopone
  • Not very interesting as a white pigment, but it can be used as UV absorber, curing agent or fungicide
Zinc Sulphide Pigment White 7
CI 77975
  • Formula: ZnS, nH2O where n=0 or 1. It can contain traces of copper. ZnO crystallizes in a hexagonal system.
  • Produces a good, strong white color, good opacity and a high degree of chemical inertness
  • It chalks badly
  • Not used very commonly. It can be used in association with other white pigments in coil coatings
Lithopone Pigment White 5
CI 77115
  • Co-precipitate of BaSO4 and ZnS. The mix of the two forms does not separate in the coating
  • Excellent Light fastness & weatherability
  • Can be degraded under UV light and lead to a grayer color.To avoid this degradation, it is possible to add nicker or iron during the preparation of lithopone, before calcination cobalt or copper
  • Can be used in every type of coating
Antimony Oxide Pigment White 11
CI 77052
  • Formula: Sb2O3, It is inert and moderately opaque
  • Originally used to reduce the chalking of anatase titanium dioxide
  • Has excellent light fastness and high heat stability
  • Mainly used in fire-retardant paints, because its heavy gas can choke flames

Yellow Pigments for Coatings and Inks

A large number of organic and inorganic yellow pigments are available. They differ by their:

  • Brightness of shade
  • Opacity
  • Fastness requirements
  • Physiological properties, and
  • Economic considerations

These properties influence the choice of the pigments depending on the end application. As well as being used in yellow paints, yellow pigments are also used in oranges, greens and browns.

Lead chromate Pigment Yellow 34
CI 77600
CI 77603
  • Yellow Lead Chromates have very bright shades and high chroma, making them ideal for full shade yellow paints
  • Excellent opacity and solvent resistance
  • Fading can occur because they are sensitive to alkalis and acids
  • Their light fastness is usually satisfactory in full shade, but they darken on exposure to light
  • Contains both lead and chromium (VI) which effectively limits their application to certain industrial finishes
  • Warning labels are required on European paints using these pigments
  • Disposal of waste can also be problematic and local regulations carefully followed
Cadmium yellow Pigment Yellow 37
CI 77199
  • Gives good quality light fastness in full shades, however, when exposed to industrial atmospheres it discolors and fades
  • Presents bright colors with high chroma
  • Offers excellent solvent and alkali resistance and high heat stability
  • Toxic in nature. Thus, in Europe, its use in nearly all coatings is prohibited for environmental reasons
Yellow oxides Pigment
Yellow 42 & 43
  • Excellent light fastness, durability, dispersibility
  • High resistance to chemicals and solvents
  • High refractive index and good hiding power
  • Limited heat stability - When exposed to temperatures higher than 105°C they begin to lose water, causing their shade to shift towards red. This color shift accelerates as the temperature or time of exposure increases
Bismuth vanadate Pigment Yellow 184
  • An intense, bright yellow pigment with a greenish shade
  • When combined with organic pigments, it generates very bright shades with high chroma and high covering power
  • Has high opacity, light fastness, excellent heat and solvent resistance and good hiding power
  • Can only be harmful at high concentrations. Low dusting grades minimize this risk

Extender Pigments for Coatings and Inks

  • Extender pigments are added in order to reduce the cost of a paint formulation. They are also used to modify the flow (viscosity), sedimentation stability and film strength.
  • Most extender pigments appear white and possess a refractive index similar to commonly used binders.
  • Most of the extender pigments occur naturally and others can be produced synthetically.
  • Aluminium silicate, magnesium silicate (talc), silica, calcium carbonate (synthetic and natural) and barium sulfate are some commonly used extender in paints and coatings.

Aluminium silicate (china clay) Pigment White 19
  • Formula: Al2O3, 2SiO2, 2H2O
  • Inert and has a good color
  • Excellent chemical stability and light fastness
  • An inexpensive flatting agent that produces a structure that improves the suspension of other pigments
  • Imparts some thixotropy in paints
  • Mainly used in water-borne decorative paints
Magnesium silicate Pigment White 26
  • Formula: 3MgO.4SO2 H2O
  • Inert and hydrophobic
  • Does not settle in the wet paint because of its plate-like form
  • Provides some resistance to humidity, improves flow behavior, and enhances the sanding properties of paint films
  • Used in both water- and solvent-based decorative paints, in undercoats and industrial finishes, in coatings for building and construction, and in anti-corrosion paints
Silica Pigment White 27
  • Formula: SiO2
  • Fine particle size
  • Has excellent chemical stability
  • Used as a matting agent to reduce paints gloss
  • Improves intercoat adhesion and the sanding properties of the paint film
Calcium carbonate Pigment White 18
  • Formula: CaCO3
  • used in water- and solvent-based paints, for interior and exterior decoration, and in many other coatings
Barium sulphate Pigment White 21, 22
  • Formula: BaSO4
  • Very inert and insoluble
  • Natural barium sulphate is used in anti-corrosion paints, industrial paints and coatings for building and construction
  • Synthetic barium sulphate is used in primers, undercoats, and industrial finishes

Corrosion Inhibiting Pigments for Coatings & Inks

Corrosion is the destruction or degradation of metal by chemical attack. Corrosion inhibiting pigments can help prevent corrosion by:

  • Physically obstructing the passage of water and oxygen
  • Protecting the anodic sites that have become pitted
  • Providing soluble pacifying ions to protect the metal
  • Producing an insoluble film to prevent active corrosion

Most of these pigments can be toxic because of lead or chrome VI they contain. Corrosion inhibiting pigments have to be selected carefully depending on the application.

Red lead Pigment Red 105
  • Formula: Pb3O4
  • Reacts with the acidic groups in the resin to produce lead soaps that passivate iron and steel surfaces
  • Mainly used in primers for metal protection
Basic lead silicochromate  
  • Formula: PbSiO3 3PbO PbCrO4 PbO3
  • Easily dispersible
  • Imparts a high quality metal protection in automotive paints and structural steel
  • Finer grades find use in electrocoat paints
Zinc chromate Pigment Yellow 36
  • Formula: ZnCrO4
  • Liberates chromate ions, which passivate metal surfaces, producing a protective film at the anodes that prevents the anodic reaction
  • In the past they have been used for iron, steel and aluminium protection, however their physiological properties make them unsuitable
Calcium, strontium and zinc molybdate  
  • Formula:CaMoO4, SrMoO4, ZnMoO4
  • These three pigments passivate the anode
  • Their use has grown considerably in recent years on account of their more favorable physiological properties
Calcium plumbate Pigment Brown 10
  • Formula:Ca2PbO4
  • A powerful oxidizing agent which also reacts with the acid groups in binders and fatty acid groups such as linseed oil to produce lead and calcium soaps
  • Its corrosion-inhibiting effect is a result of the pigments capacity to oxidize soluble iron compounds formed in anodic areas, which then form an insoluble film of iron compounds at the anode. This neutralizes that element of the corrosion cell and restricts any further corrosion
  • Promotes adhesion in the paint film and confers toughness
Zinc phosphate Pigment White 32
  • Formula: Zn3(PO4)2 2H2O
  • offers good durability, excellent intercoat adhesion and good flow properties in paint systems
  • In industrial atmospheres, it reacts with ammonium sulphate to form complex hetero acids, which inhibit corrosion
Zinc dust Pigment Metal 6 & Pigment Black 16
  • Formula: Zn
  • Fine bluish grey powder that reacts with alkalis to produce zincates and with oils to make zinc soaps
  • Corrosion resistance is generated via a sacrificial chemical reaction of the pigment rather than the steel substrate
  • protects film formers in exterior coatings by absorbing UV radiation

Commercially Available Inorganic Pigments

Explore all inorganic pigment grades available in market today!

Polymer Application Understand Pigments Used in Paints, Inks and Coatings Polymer Application Get Detailed Information on Organic Pigments

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1 Comments on "Inorganic Pigments for Paints, Coatings and Inks"
Thaer M Oct 16, 2018
very useful article for R&D Chemists

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