Indian PaintIndustry – Current Scenario Introduction of Vimal Microns Limited Importance of Extender in Paint Industry Introduction of 2 Micron Calcium Carbonate – CARB 201 Introduction of 2 Micron Talc – TALC 2 M Introduction of CARB 10 B to Small Scale Paints Manufacturers
Total Market is more than Rs.15,000 Crore Decorative segment has an edge compare to Industrial Segment in ratio of – 70:30 Few Corporate Giants have share of almost 55 % of the entire market Small Scale Paints Manufacturers are catering around 45% of the market demand
Per capita consumption of Paints in India is 1.25 kgs. Compare to other develop countries it is too low Growth of Small Scale Paints Manufacturer – more than 20% during last couple of years. Market Prediction – Should double by 2013.
Founded in 1995-96, under direction of Mr.G.K.Patel. Flagship company of VIMAL GROUP OF INDUSTRIES – Having turnover of more than 1700 Crore INR. Producing around 1,20,000 MT per Annum. Having Two state of the art units located at Mehsana & Alwar. Specialize in Micronizing of Minerals such as CALCITE, TALC, DOLOMITE, BARYTE, CHINA CLAY, SILICA, WHITE WHITING & MICA.
SECONDARY PIGMENT :Which can be used to improvecertain properties in Paints.
Mineralogy (crystal structure, Mohs hardness, etc.) Oil absorption, brightness, pH, refractive index, etc. Chemical Properties Particle size and particle size distribution Particle shape and aspect ratio
Mohs hardness is a relative measure of abrasion resistance of a mineral. Talc is the softest mineral and diamond is the hardest. Harder minerals will have better scrub resistance and better burnish resistance.
The oil absorption of a mineral is a characteristic of the mineral itself and depends how finely it is ground. The denser the mineral, the lower the oil absorption. The oil absorption indicates the amount of the resin the mineral will absorb and affects the viscosity of the paint and the gloss.
The dry brightness and color of a mineral in oil will affect how the mineral appears in a coating. A mineral can have excellent dry brightness but change color when put into a resin. Color in oil can vary from cream to gray or even green, depending on the mineral. The color is usually an effect of minor impurities.
pH is a function of the metallic ions in the structure. Aluminum in the structure makes the mineral acidic. Calcium, potassium, barium or sodium make the mineral alkaline. Some minerals, such as calcite or serpentine, are soluble in acids and can’t be used in coatings that have pH <7.
Extenders do not enhance the true opacity or color of the coating film. The refractive index is a measure of how light is bent when it passes from one medium to another. The higher the refractive index, the more the light is bent which results in greater opacity. Rutile TiO2 has a high refractive index and gives good opacity to paints. All extenders have refractive indexes that fall in a range between 1.45 and 1.65, they have a significantly lower refractive index than TiO2 and don’t contribute to the opacity, but they can be used in conjunction
While the physical aspects of extenders are of particular importance to their use in Paints, so is their chemical make up. Whiting may be of value as a pigment for anti-corrosive paints, Larger particle sized pigments, which are favored for metal primers, give coarser films with better flow and tooth for improved intercoat adhesion. Fine, wet ground and precipitated Carbonates are used in gloss finishes and enamels, while intermediate sized pigments are favored for semi-gloss pigments and flats. Whiting of intermediate fineness is also used in exterior house paints, where the pigments improve mildew resistance, reduce chalking as well as assist in controlling cost. Larger sized grades of whiting are said to give good color retention in exterior house paints.
Mica has also been used as an extender. As mica is more chemical resistant than aluminum, this extender is particularly valuable where the paints is exposed to conditions of extreme pH. China Clay may be used more effectively in inhibitive systems. China clay that are platy like the Talc, will also tend to reinforce the film, and are said to improve the sanding of industrial primers.
Baryteis a small inert nodular pigment that packs well and gives excellent enamel holdout properties. Baryte is available in two forms, naturally ground Baryte and the less common but whiter precipitated grade, which is usually finer and higher in oil absorption than the natural product. Baryte is the heaviest extender with the lowest oil absorption characteristics. It is widely used in low VOC systems, but needs some additional support in order to control settling.
The particle size of a mineral can be expressed in several ways, depending on the method by which it is measured. Common methods of measuring particle size are Hegman fineness, screening, sedimentation and laser light scattering method. Laser Light Scattering method is the latest and most advance method. Each method will yield a distinct result. When comparing data of different minerals, be sure that the particle size distributions are measured the same way.
Hegman fineness measurements indicate only size of the coarsest particles. This is a good first approximation of the fineness of grind and the dispersion of the mineral pigments in the paint. Hegman fineness does not tell anything about the overall distribution of the particle of the mineral.
Screen residue only indicates the % coarser than some given mesh size. Typical mesh sizes are 100, 200, 325, 450 and 500 mesh. These are equal to 150 μm, 75 μm, 44 μm, 32 μm and 30 μm respectively. Screenings can be done dry or wet. Wet screenings usually yield a smaller quantity retained than dry screenings.
The screen residue measures the quantity of particles retained, it does not tell anything about the size of those retained particles except that they are larger than the screen openings. 500 Mesh (30 µm) The screen residue does not tell anything about the sizes of the particles that pass through the screen except that they are smaller than the screen openings.
Sedimentation methods measure particle size by Stokes Law and yield results expressed as equivalent spherical diameter.The median equivalent spherical diameter of the mineral is often given. The median is the size where 50 % of the particles are larger and 50 % are smaller.
Laser diffraction measurement methods give a different particle size and particle size distribution than sedimentation methods. Particle size is usually expressed as D10, D50 and D99. (the percent finer than the stated micron size) Laser diffraction methods usually give a coarser particle size than sedimentation methods.
Particle Size Distribution 100 80Volume (%) 60 40 20 0 0.1 1 10 100 1000 Particle Size (µm) No Name Supplied, Saturday, December 18, 2010 1:59:43 AM
Differencesin shape and size of different extenders can lead to many practical benefits. The make up of the extender package was largely predicated on cost reduction. Since then, if only slowly, we have come to understand that care in apportioning the available extender volume between the various extenders available to the formulator can result in films with enhanced mechanical and even performance characteristics. Different paint types having different usage and performance requirements benefit from different types of extenders.
Some of the most effective fillers in terms of low oil absorption are the nodular extenders such as , Calcium Carbonate, baryte and amorphous silica (as opposed to the fumed and diatomaceous types). These materials provide little value in aesthetics, however, as do the finer Calcium Carbonate, which are used effectively in combination with TiO2 to enhance opacity. This is achieved by optimization of the manner in which the film scatters light, and is discussed below. That being said, nodular pigments contribute little to the mechanical properties of the film.
Flat,platy extenders such as Mica and some Talc and clays are also highly absorbent, again because of their very high surface area per unit weight compared to nodular extenders such as Silica, Baryte or Calcium Carbonate. These extenders tend to enhance the mechanical properties of the film by lateral reinforcement. It has also been reported that platy extenders of this type not only reinforce the film but minimize the accretion of internal stress by allowing better dissipation of stress along the plane of the pigment. Flat, platy pigmentation orientated parallel to the substrate also tends to decrease the porosity of the applied film, sealing it and reducing the tendency of high PVC primer films to bubble when recoated.
Mineral particles come in any of several basic shapes :. Sphere Cube Needle Block Plate / Flake Fiber
Needle/Fiber Aspect D Ratio : Ratio of mean L length to mean diameter Plate Aspect Ratio : Ratio of mean diameter of a circle of the same area as T D the face of the plate to the mean thickness of the plate
Aspect ratio is a description of the overall shape of the particle. It describes the length to diameter ratio, the face to thickness ratio, etc. Cubes or spheres have 1:1 aspect ratio Blocks have 2:1 to 4:1 aspect ratio (length:width) Needles or fibers have 5:1 to 200:1 aspect ratio (length:width) Plates or flakes have 20:1 to 200:1 aspect ratio (face:edge)
Talc is a platy magnesium silicate mineral. Its properties include high oil absorption, softness and high brightness . We are having an excellent quality deposits of Talc situated at Himachal Pradesh and in Rajasthan. The use of talc in coatings contributes to gloss control,TiO2 spacing, anti- settle, sandability of primers, inter-coat adhesion and corrosion/blistering resistance.
PARTICLE SIZE ANALYSIS VIMCRO TALC 2 MPHYSICAL ANALYSISResidue 400 # NilResidue 500 # 1.0% MaxDry Brightness Min. 97.0%Bulk Density [untapped] 300 – 400 Gm/LitOil Absorption 40.0 – 45.0 Gm/100 GmWater Demand 45.0 – 50.0 ml/100GmSpecific Gravity 2.7pH of Sat. Solution 9.0 – 10.0Moisture Content Max. 0.5%CHEMICAL ANALYSIS% of MgO 29.81%% of SiO2 60.32%% of AI2O3 0.67%% of CaO 1.69%% of Fe2O3 0.47%
Natural calcium carbonate (GCC) is one of the most abundant filler minerals. It forms in several crystal shapes. Shapes include blocky (chalk), scalenohedral (calcite), short needle acicular (aragonite). Calcium carbonate has high brightness, low oil absorption, can be ground to ultra fineness, and is relatively inexpensive. It is widely used in all kinds of paints and coatings, especially in interior and exterior paints. Calcium carbonate is unstable in acidic conditions and soft (poor abrasion resistance).
PARTICLE SIZE ANALYSIS VIMCRO CARB 201PHYSICAL ANALYSISResidue 400 # NilResidue 500 # 0.05% MaxDry Brightness Min. 94.0%Oil Absorption 20.0 – 25.0 Gm/100 GmWater Demand 22.0 – 30.0 ml/100GmBulk Density [untapped] 650 – 750 Gm/LitpH of Sat. Solution 9.0 – 10.0Specific Gravity 2.7CHEMICAL ANALYSIS% of CaCO3 95.0± 1.0%% of MgCo3 3.0 ± 1.0%% of Acid Insoluble 1.5 ± 0.5%% Loss On Iginition 43.0 ±1.0%
PARTICLE SIZE ANALYSIS VIMCRO CARB 10 BPHYSICAL ANALYSISResidue 400 # NilResidue 500 # NilDry Brightness Min. 95.0%Oil Absorption 23.0 – 27.0 Gm/100 GmWater Demand 24.0 – 32.0 ml/100GmBulk Density [untapped] 650 – 650 Gm/LitpH of Sat. Solution 9.0 – 10.0Specific Gravity 2.7CHEMICAL ANALYSIS% of CaCO3 95.0± 1.0%% of MgCo3 3.0 ± 1.0%% of Acid Insoluble 1.5 ± 0.5%% Loss On Iginition 43.0 ±1.0%
Natural barium sulfate, known as baryte, is a high brightness, high specific gravity, low oil absorption extender.The specialty of Baryte is High Refrective Index.Baryte is also known for its excellent compatibility with Coloured Pigments.It finds use in powder coatings because of its high specific gravity, good brightness and low oil absorption.
Hydrated Aluminum Silicate – Popularly known as Kaolin is widely used by Paints, Paper, Ceramic & Rubber Industries. Because of its Lamellar form, it gives good coverage. China Clay is chemically inert mineral. It has Higher thicksotropic nature as well as good water absorption capacity. The modified version – Calcined China Clay improves Opacity.
Dolomite is a natural form of Calcium Magnesium Carbonate with high degree of Whiteness. It is also noted for its remarkable wettability and dispersibility as well as its moderate Oil Absorption. It gives good Whiteness to the Paints, because of its Higher Bulk Density, Less Reactive.
Mica is a platy mineral. There are several different forms of mica : Muscovite, Phlogopite, Biotite, etc. Fine dry ground mica is used in joint cement and texture paints for mud crack resistance. Fine wet ground mica is used in exterior latex paints for tint retention and weatherability. Mica is used as the base for special effect pigments.
Natural silica is the most abundant mineral family on Earth. Common varieties include quartz, sandstone, silica sand, tripoli, opal and novaculite (microcrystalline quartz). It has low oil absorption, good brightness, high purity, and excellent abrasion resistance.