Ink-jet printing

Inkjet printing as its name implies is a printing method in which a jet of ink is fired, in the form of extremely small droplets, onto a receiving medium. It is a primary printing technology as the image is printed directly onto the substrate without any intermediate steps. The ink can be supplied in either a continuous manner or inter- 

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Keta.Is, Trimethylpentanediol reportedly forms a cycHc ketal by heating it with benzophenone ia the presence of sulfonic acid catalysts at reflux temperatures ia toluene (64). These are said to be useful as aprotic solvents for ink-jet printing and as inflammation inhibitors for cosmetic preparations... 

Humectants and low vapor pressure cosolvents are added to inhibit drying of ink in the no22les. Surfactants or cosolvents that lower surface tension are added to promote absorption of ink vehicle by the paper and to prevent bleed. For improvements in durabiUty, additional materials such as film-forming polymers have been added. Ink developments are providing ink-jet prints with improved lightfastness, waterfastness, and durabiUty. As a result, such prints are beginning to rival the quaUty of electrophotographic prints. 

Ink-jet printing is currently experiencing tremendous growth. It is a non-impact means of generating images which involves directing small... 

Figure 10.12 Examples of water-soluble dyes used in ink-jet printing...

Water-soluble phthalocyanine dyes may contain only sulfonic acid groups but normally contain both sulfonic acid and sulfonamido groups. They are used as direct dyes for paper and as reactive dyes for cotton. Representative examples are Cl Direct Blue 199 (38) and Cl Reactive Blue 71 (39). These dyes are also used for the ink jet printing of textiles (see Section 9.12.6.2). 

Ink jet printing is now the dominant non-impact printing technology. It has achieved this position from a platform of low cost, full color, very good (and ever improving) quality, and reasonable speed. For example, good quality color inkjet printers currently retail for ca. US 70, whereas the cheapest color laser printer costs ca. US 1,400 at the time of writing 43... 

For textile ink jet printing, conventional 2 1 Cr3+/Co3+ azo dye complex blacks are used, such as Cl Reactive Black 8 (S8).46... 

There have also been attempts to obtain a black phthalocyanine dye for ink jet printing. Thus, a patent47 from Nippon Kayaku describes reacting the amino phthalocyanine (59) with acrylic or methacrylic acid to produce the black dyes (60). 

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