Tinting

The tendency of the color to become darker with time is often indicative of chemical degradation. The test is conducted with the aid of a colorimeter (NF T 60-104 and ASTM D 1500) and by comparison with colored glass standards. The scale varies from 0.5 to 8. The French specifications stipulate that diesel fuel color should be less than 5, which corresponds to an orange-brown tint. Generally, commercial products are light yellow with indices from 1 to 2. 

Finally, color is always examined since the solvent should be colorless when pure. Traces of heavy aromatics give the solvent a yellow tint. 

The niolcciilar dynamics method is useful for calculating the tint e-dependent properties of an isolated inoleciile. However, more often, one Is interested in th e properties of a molecule that is in ler-aclin. with other molecules. With IlyperC hem, yon can add solvent molecules to the simulation explicitly, but the addition of many solven t molecu les will make the sun u lation much slower. A faster so In Lion is to sim n late them otion of th e m olecu le of in Lercst n sin g Lan gevin dyn am ics. 

An in ilial assuni ption is th at the reaction Lakes place with maxi-rn tint overlap between the HOMO on on e rn oleculc an d th e I.L MO on the other, fti e HOMO of ph en ylbuLadiene h as m ost den sity on the terminal carhon atom. 

Although phenol gives these marked colour changes, the test is unsatisfactory with many other phenols, the precise tint obtained varying with the purity of the phenol, amount of reagents used, and temperature and time of heating. 

Heat reagent-grade material for 1 hr at 255-265°C. Cool in an efficient desiccator. Titrate sample with acid to pH 4-5 (first green tint of bromocresol green), boil the solution to eliminate the carbon dioxide, cool, and again titrate to pH 4-5. Equivalent weight is one-half the formula weight. 

Tin Sol process Tin sphene Tinstone Tin sulfide Tinted contact lenses Tinted sealers Tin tetrachloride... 

Property Ultra fine High tint Low tint... 

The salt is packaged ia 45-kg multiwaH bags or fiber dmms of 45, 170, or 181 kg. It is available ia both powdered and granular forms with densities of 1.04 and 1.44 g/cm (65 and 90 lb/fT), respectively. Only the powdered grade is authorized by and registered with the EPA for use ia pesticide formulations, with the further proviso that it must be tinted blue or green, or otherwise discolored. The word poison appears on all labels together with first-aid information. 

Testing of phthalocyanines includes crystallization (qv), flocculation, and appHcation in paints, plastics (qv), and printing inks (1). The ASTM standard specifications include CuPc in dry powder form for various appHcations (153). The specifications cover color (qv), character or tint, oil absorption, reactions in identification tests, and dispersions and storage stabiUty. Quantitative deterrninations are possible with ceric sulfate (30) or sodium vanadate (154). Identification methods are given (155), including tests for different appHcations. 

Hiding power and tinting strength of a pigment also depend on concentration in the organic matrix. The concentration is usually expressed as the pigment volume concentration ... 

InstmmentaHy, both the hiding power and tinting strength can be determined from the amount of the incident light reflectance of coated white and black substrates. Relationships derived from Kubelka and Munk theory (6) are appHed in actual calculations. 

Reds. Para Red or Pigment Red 1 [6410-10-2] is an intense, reasonably opaque red which shows poor lightfastness, particularly in tints. 

ASTM E20-843 for color strength in ink, and ISO 8781 (parts 1—3) for evaluating tinting strength, fineness of grind, and gloss. 

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