The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 1999
Filed:
Apr. 16, 1997
Dainichiseika Color & Chemicals Mfg. Co., Ltd., Tokyo, JP;
Abstract
An aqueous pigment dispersion is formed of a pigment, an aqueous medium and a dispersant resin. The dispersant resin contains a hydrophobic moiety and a hydrophilic moiety in its molecule. The hydrophobic moiety is a polyester linkage chain formed of ester linkages as primary linkages. The hydrophilic moiety is a water-soluble resin containing sulfonic groups or their salts. The water-soluble resin can be produced, for example, by reacting a polyol with maleic acid and/or fumaric acid to synthesize an unsaturated polyester resin and then adding acid sulfurous acid or its salt to the unsaturated polyester resin to form groups represented by the following formula (I): ##STR1## wherein M.sup.1 represents a hydrogen atom, an alkali metal, an ammonium group or a lower aliphatic quaternary ammonium group. The aqueous pigment dispersion is useful as a water-based ink for writing or recording equipments such as writing instruments, printers, copying machines, fax machines and printing machines.