Research Of Highly Water-Soluble And Weather-Durable Ink-Jet Dyes

Compared with pigment-based inks,dye-based inks have many advantages such as full tone,high optical density,vivid images,low cost and easy preparation.However,dyes are susceptible to light and ozone gas.Dye is the key to sole the problem.Therefore,the research and development of new dyes with new structures and excellent properties are very important for the practical applications.Three sulfonic vat black dyes(vat black 8,vat black 9,vat black 38 and vat black BCN) were synthesized via sulfonation.The sulfonic derivatives of vat black 8 and vat black 38 have not been reported before.When the cation is Na⁺,weather durabilities on Kodak and Epson glossy papers show that vat black 9 has the best properties.In the case of sulfonic vat black 8, N⁺H(CH₂CH₂OH)₃ behaves the best water solubility and Li⁺ with the best weather durability. For sulfonic vat black 38,N⁺(CH₃)₄ shows the best water solubility and Li⁺ with the most excellent weather durability.Various chrome complex dyes(1:1 ratio) of mordant black 1,mordant black 7,mordant black 9 and mordant black 11 have been synthesized and sodium dichromate is been used as mordant agents instead of Cr³⁺ to oxidate dyes sufficiently.The introduction of acids into the reaction make complex dyes highly water soluble and this synthesis process has not been reported before.When the acid is tartaric acid,weather durability tests show that mordant black 7 and mordant black 9 have better properties.The derivatives of mordant black 7 and mordant black 9 have the best water solubility when citric acid is added and the best weather durability when oxalic acid used.New multisulfo-group containing azo ligands for metal complex dyes are synthesized. Instead of 4-amino-3-hydroxy-benzenesulfonic acid,4-amino-3-methoxy-benzenesulfonic acid are used as diazotization agent and make the coupling reaction more easy.Through the weather acceleration tests,5 new dyes with good fastness are obtained.These dyes possess several sulfonic acid groups and behave excellent water solubility in ink,and water fastness and rubber fastness in images.