Fastness to soap

Pigment Red 8 affords clean, bluish shades of red. It is primarily used in the printing ink industry. P.R.8 exhibits high tinctorial strength and produces brilliant prints. Commercially available types with specific surface areas between about 50 and 60 m2/g afford transparent prints. P.R.8 is used in prints which require no particular solvent resistance. However, the pigment tolerates solvents much better than the yellower P.R.7 in this respect, P.R.8 matches the yellower, but more light-fast P.R.5. The prints are fast to soap but not entirely stable to butter and paraffin. P.R.8 is sensitive to clear lacquers coatings and to sterilization. It tolerates exposure to 140°C for 30 minutes. 

P.R.184 affords a red which is somewhat on the bluish side of P.R.146, to which it is closely related in terms of chemical constitution. Both products also behave very similarly in application. Their prints are fast to soap, butter, paraffin, dibutyl phthalate, white spirit, and toluene. P.R.184 produces a shade which matches that of the standard magenta for multicolor printing on the European Color Scale CIE 12-66. This shade results from formulating an ink at 15% pigment concentration and printing the ink in a standard layer (1 pm). 

The free sulpbonic acid is blue, the salts are scarlet, and give the same shade on cotton. These shades, though fast to soap, are unfortunately turned blue -by weak acids. This property is less marked in the dyestuff known as Benzopurpurine B. It is obtained [69] from tetrazoditolyl (obtained from o-tolidine and nitrous acid) and the /3-naphthylaminesulphonic acid, obtained by Bronner from Schaeffer s S-naphtholsulphonic acid and ammonia. 

The indophenols are very fast to soap and light their great sensitiveness towards acids and certain difficulties encountered, in their application, hoM ever, render them unable to compete with indigo. Indophenol, however, appears to he of use when combined with indigo, i.e. when a vat of the mixed dyestuffs is used. It is claimed that this mixed vat is more economical than thesimpleindigo vat, while the fastness and beauty of the shades are not affected. 

The shades are very fast to soap. Like canarin and the direct dyeing tetrazo-colours, Cachou de Laval is capable of fixing basic dyestuffs, and the shades can thus be topped at will. 

It is a greenish-blue dyestuff, tolerably fast to soap and light, and recommended as a substitute for indigo-extract. 

USE Has been used to dye Cr mordanted wool yellow. The color is fast to soap. 

Uses Dye for Cr mordanted wool yellow Features Color is fast to soap Manuf./Distrib. Aldrich http //www.sigma-aldrich.com, Fluka http //www.sigma-aldrich.com, Kaden Biochems. http //www.kadenbio.com] Sigma... 

Goumanns. By treatment of flax with escuUn, a glucoside of esculetin [305-01-1] (10), a brightening effect is achieved however, this effect is not fast to washing and light. The use of P-methylumbeUiferone [90-33-5] (11) and similar compounds as brighteners for textiles and soap has been patented. 

P.Y.l prints are comparatively sensitive to most common organic solvents, such as esters, ketones, and aromatic hydrocarbons, but completely fast to alcohols and aliphatic hydrocarbons. The prints are also resistant to soap, alkali, and acid. 

DIN 16 524 solvent blend (Sec. 1.6.2.1). While the pigment lacks butter and paraffin fastness, it is completely resistant to soap. P.O.5 is not used for metal printing or for decorative printing. 

In applications where the pigment is fast enough to solvents to satisfy the requirements, it may also be used for offset, packaging gravure, and flexo printing inks. The resulting prints are soap, alkali, and acid resistant. They are not completely fast to paraffin and quite sensitive to butter and a number of other fats. P.R.14 prints are not fast to clear lacquer coatings and may not be sterilized. Heat stabil-... 

P.R.17 provides medium reddish shades. As a result of poor fastness properties, its commercial significance is somewhat limited and it is sold only in small volume. P.R.17 has the advantage of being fast to acid, alkali, and soap. It is therefore used in offset, gravure, and flexo printing inks wherever tolerance to alkali and soap is a major concern. Moreover, P.R.17 is also employed in connection with mass coloration and surface coloration of paper. 

The prints tolerate white spirit, dibutyl phthalate, butter, soap, alkali, and acid. Moreover, they are also stable to clear lacquer coating their fastness to sterilization, on the other hand, exceeds that of P.R.57 1, but is not perfect. Where sterilization fastness is required, P.R.146 is superseded by P.R.185, a benzimidazolone pigment, which is its coloristically closest neighbor. 

P.R.146 is a suitable candidate for a variety of special applications. The list includes wood stains, in which it is frequently blended with yellow pigments, especially with P.Y.83, and also with black to afford shades of brown. The products are fast to overcoating and stable to nitro and acid catalyzed and polyester varnishes. Intense shades match step 5 on the Blue Scale for lightfastness. Other areas of application include office articles and artists colors, cleaning agents, paper mass coloration, laundry markers, etc. In connection with cosmetics, the pigment frequently lends color to soaps. 

P.R.184 is used especially in applications where P.R.57 1 fails the requirements for alkali, acid, or soap fastness, or where the pigment lake is not lightfast enough to satisfy the demand. Depending on the standard depth of shade, the lightfastness of P.R.184 exceeds that of P.R.57 1 by approximately one step on the Blue Scale. Excellent fastness to solvents makes P.R.184 a suitable candidate for letterpress... 

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