Silica
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Silica
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Color Index
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Pigment White 27
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Formula
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SiO2
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Structure
Silica is available in natural and synthetic forms. Natural sources include diatomaceous
earth, "amorphous" silica and crystalline silica (quartz). The synthetic
grades include precipitated silica with extremely small particle size, which can
even be colloïdal.
Properties
Silica can have a fine particle size. Then, it can be used as a matting agent to
reduce paints gloss. It can also improve intercoat adhesion and the sanding properties
of the paint film.
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Properties of silica
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Property
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Quartz
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Precipitated silica
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Refractive Index
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1.5
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1.45
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Density
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2.6
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2.1
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pH
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7
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3-3.5
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Mohs hardness
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7
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-
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SiO2 content
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-
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87-99%
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Specific area
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-
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250-300 m2/g
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Chemical stability
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excellent
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-
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