Patents
The invention provides water soluble confined organic colourants for colouring application with monodispersed particles. These confined colourants uniformly colour the substrate without any infiuence of the substrate environment especially in leather colouring. The present invention essentially provides an opportunity to colouring leather at any stage of wet processing of leather, rather than the conventional system of leather colouring after tanning and neutralization of the hide/skin. Confinement of colourants inside the novel polymeric matrix ensures this. These colourants are used in colouring application devoid of any influence of the charge and pH of the substrate, leading to uniform colouring and improved fastness and perspiration resistance. Hence the metal organic matrix penetrates and fix into the substrate without any need of fixing agent and colouring auxiliaries.