Full shade

These pigments are sensitive to heat and bleed ia most paint solvents. They are, however, resistant to acids and bases. Their tinctorial strength is considerably greater than that of inorganic yellows but they are weaker than the diaryUde yellows. They are used extensively ia emulsion paints, paper coating compositions, inks (qv), and, depending on particle size, can ia some cases be used outdoors because of excellent lightfastness ia full shades. 

VoU-ton, m. full tone, full shade, mass tone. 

P.R.123 baked 5% in full shade in alkyd/melamin resin paint 30 min, 120°C 30 min, 240°C 225xl0 10m 340xl0"10m... 

P.R.122 baked 5% in full shade in polyester-modified silicone resin system 60 min, 200°C 60 min, 300°C 245xlO"10m 295xlO-10m... 

Monoazo yellow pigments exhibit good lightfastness and durability in full shades and close to deep shades. In order to optimize the pigment performance for a certain target application, physical parameters, such as particle size or crystallinity, may be adjusted accordingly. It should be mentioned, however, that such techniques do not open up new areas of use. 

P.Y.97 is used in a variety of fields. Even in pastel shades, it is used in industrial finishes while its full shades lend color to automobile refinishes. In emulsion paints, both its medium and full shades are suited to exterior application. The printing ink industry uses P.Y.97 in high grade printing products, especially where excellent fastness is required, such as in stable posters, etc. It lends itself without difficulty to all printing techniques. However, lack of fastness to monostyrene and acetone and therefore a certain tendency to bleed in these media precludes its application in deco printing inks, i.e., for decorative laminates. 

P.Y.167 enjoys only regional importance and is recommended for application in paints. The currently available type provides medium hiding power. In full shade and in similar deep shades, it shows a medium yellow white reductions are greenish yellow and very clean. Its fastness properties correspond to those of other monoazo yellow pigments P.Y.167 is not alkali resistant. 

The paints market shows only limited interest in P.Y.55, although the pigment is occasionally used to lend color to low quality industrial paints. In 1/3 SD white reductions, the pigment matches the lightfastness of P.Y.13 samples its full shades are more lightfast. Addition of TiOz decreases its resistance to light. 

In the paint field P.Y.16 is primarily used in industrial finishes. The similarity to P.Y.l is limited to a likeness in shade but P.Y.16 is fast to overcoating and shows no tendency to bleed in baking enamels. Although its full shade lightfastness equals step 7-8 on the Blue Scale, types that are only slightly reduced with TiOz (1 5) reach only step 5. Only full shades provide good weatherfastness. 

In the paint industry, transparent types are used only to a limited extent. In air drying systems, P.O.34 equals step 6-7 on the Blue Scale in full shades, while opaque colorations with TiOz (1 5) only reach step 3 for lightfastness. In baking enamels, the pigment is not fast to overpainting. 

Although standard types resist light well, especially in full shades, they are not as fast as most monoazo yellow pigments. Lightfastness is lost rapidly with decreasing depth of shade and decreasing pigment area concentration, respectively. The commercially available types disperse easily in most media. 

Full shades of Toluidine Red are extremely lightfast and weatherfast, but deteriorate rapidly as the pigment is reduced with white pigment. In full shades, the lightfastness equals step 7 on the Blue Scale, while 1 4 Ti02 reductions only reach step 4. The pigment is therefore used preferably in full or similarly deep shades. Recommendations include emulsion paints for interior application or short-term advertisement and marking purposes. 

P.R.3 is very likely to bloom in baking enamels. At 120°C, the concentration limit for blooming is 2.5% beyond about 140°C, blooming occurs with certainty, irrespective of the concentration. Therefore, only full shades of P.R.3 are used to color baking enamels, and only where application temperatures are low. The pigment is used extensively in combination with Molybdate Red. 

In plastics, Toluidine Red is practically limited to rigid PVC. Its lightfastness in full shades and slight white reduction is fair. Besides, the pigment is also used to color a number of specific media, such as normal wax crayons and pastel chalks or low-cost watercolors. 

P.R.4 is also known as chlorinated Para Red. It has lost much of its commercial impact in recent years. The pigment affords a yellowish red shade, somewhere between the more yellowish P.O.5 and the more bluish P.R.3. Tinctorially, P.R.4 is the weakest of the three. In order to formulate equal depth of shade in an air drying alkyd system, three equivalents of TiOz are necessary per equivalent of P.R.4 while P.O.5 and P.R.3 require 5 and 6 parts of TiOz, respectively, per equivalent of organic pigment provided all other parameters are equal. Full shades exhibit good lightfastness (step 6), but darken somewhat upon exposure. Addition of even... 

P.R.14 is very lightfast its full shade lightfastness in air drying systems equals step 6-7 on the Blue Scale in baking enamels, it reaches step 7-8. In white reductions (1 7 Ti02), the lightfastness of the same systems equals step 5-6 and 6-7, respectively. 

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