Synthesis of Polyester-Polyamine Dispersants and Their Carbon Dispersing Properties

Abstract

Abstract − We prepared polyester-polyamines to improve the effect of carbon black dispersibility for use in ther-mal transfer ink, and synthesized polymeric dispersing agents by two-step reactions. In the first step, we made polyester by polycondensing 1,6-hexanediol and adipic acid. The resulting polymers had carboxylic acid, which was linked with polyamine via an acid-base reaction. We then characterized the polyester-polyamine structure by NMR spectroscopy and Fourier transform infrared spectroscopy (FT-IR). We also determined the basic char-acterizations such as total acid numbers (TAN) (5.0−67.5 mgKOH/g), hydroxyl values (27.1−67.5 mgKOH/g), and molar masses (Mn = 1.6−8.4 kg mol −1) for the polyester and total base numbers (TBN) (15.3−57.1 mgKOH/g), hydroxyl values (33.0−79.8 mgKOH/g), and nitrogen contents (1.02−3.48%) for the polyester-polyamine polymers. We thus prepared thermal transfer ink using carbon blacks and the polyester-polyamine dis-persing agents, and evaluated the resulting mixtures for printability, adhesive force, storage stability, ink appear-ance, ink gloss, and processability. These mixtures showed significant dispersibility for carbon black in the ink. Thus, we concluded that the dispersibility of the polymeric materials depended on the polyamine structure an