Ink formulations by mixing anionic waterfast dyes containing two or more carboxyl groups
Patent 5062893 Issued on November 5, 1991. Estimated Expiration Date: 
June 22, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 22, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesWaterfast ink formulations with a novel series of anionic dyes containing two or more carboxyl groups Patent #: 4963189 InventorsApplicationNo. 542862 filed on 06/22/1990US Classes:106/31.52, Plural acyclic azo group component containing106/31.43, Organic nitrogen compound containing106/31.46, The nitrogen is a ring member of a heterocyclic ring106/31.58, Organic oxygen compound containing534/824, Nitrogen, other than as nitro, nitroso or azo, attached indirectly to azo by nonionic bonding534/836, Additional hydroxy or nitrogen, other than as nitro, nitroso or azo, bonded directly to the bicyclo ring system534/837Sulfonic acid group bonded directly to the bicyclo ring system (-(0=)S(=0) OH, wherein H of the -OH may be replaced by the ammonium ion or a Group IA or IIA light metal)ExaminersPrimary: Dixon, William R. Jr.Assistant: Einsmann, Margaret International ClassC09D 011/00AbstractInks are provided comprising (a) at least two dyes corresponding to the formula ##STR1## wherein W is COOH,X is H, or COOH,Y is H, COOH, or SO3 H,Z is H, COOH, or SO3 H, andR is H, CH2 COOH, or CH2 CH2 COOH;with the proviso that there are at least two COOH groups and that the number of COOH groups is equal to or greater than the number of SO3 H groups, and (b) a solvent which may be water or a mixture of water and a water-soluble organic solvent provide excellent waterfast prints on paper. The inks preferably have a pH from about 7 to about 9.5. Also preferably, a phosphate is added to reduce kogation and a metal chelating agent is added to further reduce nozzle clogging. |
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