Effects of Single and Blended Coating Pigments on the Inkjet Image Quality of Dye Sublimation Transfer Printed Paper: SiO₂, CaCO₃, Talc, and Sericite

Table 1

Physical properties of the 4 pigments investigated [12, 13].

Item	Silica	GCC, H90	Talc	Sericite
Main ingredients		CaCO3 98.3%		SiO2 54%; Al2O3 31%; K2O 7%
Crystalline structure	Tetragonal	Rhombic	Monoclinic	Monoclinic
External appearance	Platy	Spherical	Platy	Platy
Specific surface area (m^2/g)	>100	14	9~20	57
Hardness (Mohs)	2.2~2.6	3.2~3.5	1.0~1.5	2.2~2.4
Range of particle size (µm)	0.01~0.10	0.1~ 4.0	0.25~5.0	0.8~45.0
Average particle size (µm)	0.09	0.39~0.41	1.2~1.5	10.0~14.0
Specific gravity	3.42	2.67	2.7	2.6~2.7
Refractive index	1.55	1.56	1.57	1.59~1.62
Reflectance (%, at 457 nm)	—	95	97	70
Brightness (% ISO)	85~95	93~96	73~80	65~75
pH	8~11	8.8~9.6	4~5	7~9
Aspect ratio		1	—	30~40
CEC (meq/100 g)		—	−15.7	5.0
PCD (meq/g)		−1.9	72.5	−48.4

GCC: ground calcium carbonate; CEC: cation-exchange capacity; PCD: particle charge detector.