| abstract |
PCT No. PCT/EP98/02699 Sec. 371 Date Jan. 11, 1999 Sec. 102(e) Date Jan. 11, 1999 PCT Filed May 17, 1998 PCT Pub. No. WO98/53285 PCT Pub. Date Nov. 26, 1998Process for calculating colour formulations of pigmented special-effect shades wherein i) for each pigment on which a colorant system is based a set of calibration panels is created, and the associated reflection factors are determined experimentally, ii) from the measured reflection factors for each pigment on which the colorant system is based, the optical material parameters are determined using a radiation transport model to describe the diffusion of light in particulate media, iii) from all the platelet-like special-effect pigments on which the colorant system is based and in each case a fixed quantity of one or more colouristically inert topology-influencing fillers, so-called pseudopigments are formed whose optical material parameters are likewise determined by way of a calibration scale, iv) and, the formulation components and pigments and/or associated pseudopigments from a colorant system being specified, the reflection spectra of a special-effect shade which is to be rematched are simulated mathematically by reference to the optical material parameters, using a suitable radiation transport model to describe the diffusion of light in particulate media, with the associated quantity resulting in respect of each pigment, each pseudopigment and the topology-influencing filler. |