Pigment Blue 29 (PB29), commonly known as ultramarine blue, has the CAS number 57455-37-5. Its chemical formula is Na8-10Al6Si6S2-4O24, representing a complex sodium aluminosilicate framework with encapsulated polysulfide chromophores responsible for its characteristic blue color.
The pigment has a refractive index of approximately 1.5, with a relative density of 2.35 g/cm³. Its particle size typically ranges from 0.5 to 8 microns depending on the grade, with finer particles producing more intense tinting in end applications.
PB29 is stable up to approximately 400°C under normal conditions, making it one of the most thermally stable blue pigments available. It is insoluble in water, organic solvents, oils, and most chemicals, contributing to its excellent durability in end products.
Shree Krishna Ultramarine Pigments (P) Limited produces Pigment Blue 29 in multiple grades tailored for different industries. Each grade is tested for color value (1/3 SD), pH, oil absorption, and heat stability before dispatch to ensure compliance with customer specifications.
The pigment complies with major global regulations including EU REACH, RoHS, and various food contact regulations. Its non-toxic, heavy-metal-free composition aligns with the global trend toward safer, more sustainable industrial colorants.