화학공학소재연구정보센터
Color Research and Application, Vol.41, No.6, 596-610, 2016
Specular gloss versus surface topography for oil-filled nanoparticle coatings on paper
The appearance or printing quality of paper surfaces is mostly characterized by their glossiness, measured with a glossmeter as specular reflectance. The gloss properties of a base paper substrate can be improved after application of a poly(styrene-co-maleimide) nanoparticle coating under pure conditions or in the presence of different vegetable oils. The specular gloss properties of 11 different nanoparticle paper coatings have been determined under 75 degrees and 85 degrees incident light angles, with good relation between values along parallel (machine) and perpendicular (transverse) direction. The gloss properties for the different coatings have been further related to the surface topography. Therefore, the statistical and spatial surface roughness parameters have been studied in detail at two length scales including non-contact profilometry (1 x 1 mm(2)) and atomic force microscopy (2 x 2 m(2)). Based on values of the Rayleigh parameter for non-contact profilometry, the surfaces can be considered as optically rough. The gloss values cannot be directly related to statistical surface roughness parameters. Otherwise, an experimental power-law model for gloss has been proposed as a function of (/Sq) with correlation length and root-mean-square roughness Sq. A best-fit model illustrates that gloss properties of various nanoparticle paper coatings mainly relate to the spatial surface roughness parameters determined from non-contact profilometry. (c) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 596-610, 2016