PURPOSE: A resin colorant that is made by allowing an organic pigment such as quinacridone to bind with or adsorb on an inorganic material such as silica gel, thus improving the shrinkage of moldings.
CONSTITUTION: An inorganic material such as silica gel or alumina, treated with a silane coupling agent or titanium one, is made to react with an organic pigment previously treated with thiocyanic acid such as quinacridone or azo pigment, or the inorganic material is added to a solution of the organic pigment in conc. sulfuric acid or alkaline solvent, then the sulfuric acid or the alkali is neutralized or diluted with an alkali or acid or precipitate the organic pigment, thus producing the objective colorant. The inorganic material is preferably 0.1W1μm in the average particle size and the amount is preferably 3W5 times the weight of the orgnanic pigment.
UENO YOSHIMI
MURAYAMA HIROSHI
