Azamethine dyes

Additional Chromophores. Other types of dyes that have been studied as chromophores in dye developers include rhodamine dyes, azamethine dyes, indophenol dyes, and naphthazarin dyes (21). Cyanine dyes, although not generally stable enough for use as image dyes, have also been incorporated in dye developers (31). 

Azamethano[ 10]annulenes synthesis, 3, 424 Azamethine dyes stabilizers... 

When treated with 4-dimethylaminobenzaldehyde, diazonium salts, or phthalic anhydride, these salts produced the corresponding styryl or azamethine dyes derived from l,2,3-thiadiazolo[4,5-/] or [5,4-/]quinolines. The Xmax of azamethine... 

Certain dyes derived from somep-phenylenediamines satisfy the requirements of practical image dyes. For example, the developer of Scheme 5 gives yellow and magenta azamethine dyes, respectively, with benzoylacetanilides and 2-pyrazolin-5-ones as couplers, and cyan indoaniline dyes result from phenols and naphthols. 

In other types of metallizable conventional dyes, the chelating site is not part of the chromo-phore, and thus there is not a large hue shift on metallization. In the yellow (66),133 magenta (67)134 and cyan (68)135 couplers the metallizable site is the l//-imidazo[4,5-/i]quinoline substituent. This allows the option for metallization before or after the generation of the azamethine dyes by reaction with oxidized / -phenylenediamine. Advantages of improved light stability and acid fastness are reported for the metallized dyes. 

The following soluble dyes fall into the category of inherently thermochromic dyes. These materials are molecules that are chemically altered by the addition of heat and display a concurrent color change. Researchers at Akzo Nobel have synthesized several infrared-absorbing azamethine dyes that possess the general formula of Scheme 18. 

Simple methines, often called styryl dyes, were once important as yellow disperse dyes bnt are now only nsed to prodnce bright bine and tnrqnoise dyes. Examples are the mono-methine (2.21), the dimethine (2.22) and the azamethine (2.23). Indophenols (2.24), another class of azamethines, have been nsed as bright bines for transfer printing onto polyester and in digital imaging by dye diffnsion thermal trans-... 

Attempts to produce dyes other than azamethines and indoanilines as images have been reported. The compound (45) with a naphtholic coupler gives a blue azo dye (46) (57GEP963297, 57GEP1000689) and the magenta azine dye (48) is formed from the p- phenylenediamine (47) and phenol. The formation of this dye requires six equivalents of silver halide (53MI11400). 

Second, 1 1 metal-complex azo dyes that contain sulfonic acid or carboxylic acid groups and are present in the form of internal salts. Here, azamethine-metal complexes are also of importance. An examples is C.I. Solvent Yellow 32, 48045 [61931-84-8] (2). 

Yellow Dyes. A yellow D2T2 dye is probably the easiest to obtain both in terms of color and properties. The leading transfer-printing yellow dyes for textiles, such as quinophthalones and azophenols, are inadequate, as are typical photographic yellows such as azamethines. Two of the most widely used dye classes are methine (12) and especially azopyridones (13) [7,11,12],... 

---