Color-coupling agents

A H ro2c ch2oc- (R = 0- (C12H2,)OC6H4 Ph c.o2h H Yellow photographic color-coupling agents 1030... 

Coccidiostatic, 152 Coding structures. 139 Color-coupling agents, 159 Colorimetry, in sulfathiazole determination. 116... 

Antioxidants Colorants Coupling agents Fillers or extenders... 

Antioxidants Anti-static agents Blowing agents Curing agents Colorants Coupling agents Fillers... 

Another useful reagent for detection and estimation of G-agents is diisonitrosoacetone (16). A magenta color is produced with 1 p.g of GB at pH 8.5. Coupling agents, such as -phenylenediarnine, increase the reaction rate. 

The completeness of coupling may be checked by the R-salt test as follows A few drops of the clear supernatant liquid is added to a small quantity of a solution of R-acid (jS-naphthol-3,6-disulfonic acid) in an excess of 2 TV sodium hydroxide. An intense red color is produced if unreacted diazonium salts are present. Obviously this test is satisfactory only if R-acid couples more rapidly with the diazonium salt than the coupling agent involved in the reactions and if the change to a red color is not obscured by other colors present in the reaction system.]... 

Color photography, now fully perfected, requires a developer like N,N -diethylphenylenediamine which reacts with silver salts. The oxidized derivative obtained reacts with a coupling agent made up of groups (-CH=) or (-CH2-) to produce the desired color. 

Coupling agents such as silanes and titanates will increase light scattering. Both types can impact colorability if they are incorporated at high levels. 

The third reaction of the sequence is the silver-catalyzed oxidation of color developing agent which leads to dye formation by coupling as in normal color development. This process allows a lowering of the coated silver level but still produces a full-density color image (Figure 16). Typically the coated silver level is 10 % of that required for normal color development, which means that 90 % of the dye image is formed by the RX amplification reaction. 

Use Intermediate in manufacture of azo dyes for textiles and plastics and as coupling agent of color pigments in color photography. 

---