| 摘要 |
<p>Specific core-shell binders and magnetic additives for use in ink-jet printing ink compositions are provided. One class of specific core/shell binders has the general formula [AmBnC'p]x, where A and B are hydrophobic components in which A exhibits a glass transition temperature Tg between about -150° and +25 °C and B exhibits a glass transition temperature greater than 25 °C, C' is a component that forms a hydrophilic or water-soluble component in the polymer chain, and has an ionic or non-ionic structure, m∫30 wt.%, n⊃40 wt.%, and p∫30 wt.%, with the total of m+n+p = 100 wt.%, and x = 1 to 100,000. The molecular weight (weight average) of the polymer is between about 1,000 and 2,000,000. The polymers useful in the practice of the invention are prepared by emulsifying the monomers and then conducting a free-radical polymerization in water. The foregoing binder polymer is used in conjunction with magnetic additives comprising either (a) inorganic magnetic compounds containing at least one of iron, cobalt, and nickel or (b) organic magnetic complexes containing at least one of iron, cobalt, and nickel or (c) organic charge transfer complexes that exhibit magnetic properties. The ratio of binder (I) to colorant (pigment) is greater than 1 to 10. The concentration of the magnetic additive is within the range of 1 to 30 wt.%. The general ink formulation comprises: 5 to 50 wt.% water-miscible solvent; 0.5 to 10 wt.% colorant; 1 to 30 wt.% magnetic additive; and water.</p> |
