The main characteristic of these products is their ability to convert ultra violet light into color. This results in extremely high levels of light reflect-ance, which leads to very striking shades of color.

These pigments are closely related to optical brighteners. With one exception (naphthaladzine C.I. Pigment Yellow 101), the products are fluore-scent dyes dissolved in a plastic matrix, as a result of which they are particulate and yield colorants with a pigment character.

The exact composition of the coating determines the applications for which they are suited, so that there are a number of ranges targeted towards certain outlets, such as solvent-based ink, plastics etc.

The advantage of fluorescent pigments is their obvious eye-catching appeal. However, this is offset by their poor light-fastness properties. Direct sunlight breaks down the pigment causing a loss of color, brightness and strength.

When formulating with fluorescent pigments the factors to be considered include:

• Brightness
• Strength
• Solvent resistance
• Heat resistance
• Light fastness
• Health and safety
• Process parameters

Ciba^® IRGALITE^® CG Ciba fluorescent pigments
Ciba^® IRGALITE^® CG fluorescent pigments are used in a wide variety of applications due to their bright glowing colors. They are finely ground resin systems that contain an encapsulated fluorescent dye.

Compared to conventional pigments, fluorescents generally have lower light fastness. Improved stability for some applications can be obtained by formulating with a higher percentage of fluorescent pigments in addition to light stabilizers. Ciba^® TINUVIN^® UV absorbers and HALS are frequently used to enhance performance.

Ciba offers a number of fluorescent pigment series, each designed to give optimum performance in its specific target application as no single fluorescent pigment is suitable for all applications.

We offer Ciba^® IRGALITE^® CG1 and CG2 series for paints and coatings.

Ciba^® IRGALITE^® CG1 series high solvent resistance and temperature stability

Ciba^® IRGALITE^® CG2 series excellent water resistance and brightness

Ciba^® IRGALITE^® CG1 series
IRGALITE^® CG1 range of pigments are dyes encapsulated in a thermoset melamine/formaldehyde/sulphonamide resin complex. The thermoset resin provides good solvent resistance and temperature stability. It is suitable for solvent-based coatings based on strong solvents like ketones, glycol ethers, esters and plasticizers as well as for UV screen applications.

Ciba^® IRGALITE^® CG2 series
IRGALITE^® CG2 range of pigments are dyes encapsulated in a thermoplastic melamine/formaldehyde/sulphonamide resin complex. The thermoplastic resin is resistant to water and weaker aliphatic and aromatic hydrocarbons only. In formulations based on these solvents, the IRGALITE^® CG2 series offers slightly higher brightness than IRGALITE^® CG1.

The IRGALITE^® CG1 and IRGALITE^® CG2 series should be mixed into appropriate varnishes using conventional high-speed stirrers. Three roll milling or beadmilling is neither necessary nor recommended as the pigments are supplied at the optimum particle size for fluorescence.