Diffusion of Disperse Dye from Capsules Containing Ferromagnetic Substance into PET Film.

Sublimation/diffusion behavior of a microencapsuled dye (1-aminoanthraquinone(AAQ), C.I. Solvent Blue 35 and C.I. Disperse Red 50) into poly (ethylene terephthalate)(PET) film was evaluated applying the film roll method. Eight kinds of microcapsules (smaller than 15 μm in diameter) containing both dyestuff and ferromagnetic substance or only the dyestuff were prepared by using acrylate resin as capsul material. Fickian diffusion profiles of three kinds of dye were obtained both from free state and from microcapsules in the temperature range from 170 to 200°C. Hence, the diffusion coefficients D could be calculated using the equation (ln C=A−(χ2/4t)·1/D), where C is the concentration at distance χ from surface after time t and A is a constant. From the temperature dependence of the D, the activation energy (ΔE) for diffusion was calculated. ΔE for diffusion from microcapsules was a little larger than from free state. It was also found that there is no influence of ferromagnetic substance on diffusion. This fact indicates that the capsule wall affected as “a very low diffusion barrier”.