ALEXANDRIA, Va., March 31 -- United States Patent no. 12,590,214, issued on March 31, was assigned to NIPPON SHOKUBAI Co. LTD. (Osaka, Japan).
"Ink-jet ink" was invented by Keiichi Nakamoto (Suita, Japan), Takumi Ito (Suita, Japan) and Yoshimine Sakamoto (Suita, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "The ink-jet ink of the present invention comprises a solvent S having an SP value of 9.1-9.4, resin emulsion particles and water. It is preferable that the resin emulsion particles contain a (meth)acrylic polymer. It is also preferable that the resin emulsion particles contain a structural unit derived from styrene. It is also preferable that the solvent S is tripropylene glycol monomethyl ether an...