Pigments types

Most pigments can be used in any type of binder therefore, paints cannot be identified by pigment type alone. For example, micaceous iron oxide pigment is traditionally in an oil-based binder but is being increasingly used in epoxies, etc. In the paint coating film, the pigment content may vary from 15 to 60 per cent. In the special case of zinc rich primers, it is over 90 per cent. 

Nakamura et al., 1988). These results suggest that F has the structure of a bile pigment type tetrapyrrole. 

The pigment industry produces primarily the more transparent diarylide yellow pigment types. This has its advantages, particularly in the field of printing inks, since yellow is printed as the last color in three or four color printing (Sec. 1.8.1.1). Highly transparent varieties are almost exclusively resinated and are often easy to disperse. 

P.Y.12 and considerably more so in comparison with P.Y.13. A number of the P.Y.14 types are appreciably greener than the standard yellow on the European Scale. P.Y.14 is not only weaker than comparable P.Y.13 varieties with similar physical characteristics, such as specific surface area but it is also less lightfast by 1 to 2 steps on the Blue Scale. Its resistance to solvents is also comparatively poor. This somewhat limits its use for process inks in offset and letterpress application to special cases, which is equally true for P.Y.14 blends with reddish pigments. Types with fine particle sizes, which match highly transparent versions of P.Y.12 and 13, are not available in Europe. 

The technique of having the coupling step precede the condensation is similarly applied to the two types of yellow pigments. Type 1 (see p. 370) is synthesized by coupling two equivalents of diazotized aminobenzoic acid onto bisacetoacetylated aromatic diamine, especially diaminobenzene. Conversion to the disazo acid chloride, followed by condensation with two equivalents of usually carbonamide substituted amine, finally affords the desired pigment. 

Figure 41. Residual gloss and AE%b values for isocyanate-cross-linked polyacrylate resins that contain 15wt% Vossen Blau 2000 (older pigment type which has been replaced by Manox Blue 460 D) relative to the binder and 15 wt% Ti02 (rutile) relative to the iron blue pigment after 1000 h fast exposure to UV [3.193] a) Without clearcoat b) With clearcoat but without UV protection c) With clearcoat and UV protection...

Field of application Pigment type Approximate particle length, pm Specific surface area, m2/g Coercive field strength 7/c, kA/m Saturation magnetization, Ms, pT m3/kg MJMS... 

The various compositions of the five pigment types are summarized as follows ... 

As stated previously throughout this chapter, the pigment types most adversely impacted by this series of federal and state regulations are cadmium, mercury-cadmium, lead chromate, and lead molybdate colorants. Generally, these regulations make a distinction between hexavalent chromium, which is preceived as carcinogenic, and trivalent chromium. It is this distinction that allows the con-... 

Pigment Type Colour Index Name Heat Stability (°C) Tinting Strength Opacity Lightfastness ... 

Figure 10.3. Surface treatment of Ti02 pigments. Types and generalized purpose of coating.

The particle sizes relevant for inorganic pigments stretch between several tens of nanometers for transparent pigment types to approximately two micrometers. For practical applications it is very desirable to determine not only the mean particle size but also the whole distribution. These parameters must not be confused with the crystal size determined by X-ray diffraction, as pigment particles usually are not monocrystals. 

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