Лако-красочные материалы — производство

C. I. Pigment Red 254 was introduced to the market in 1986 as the first represen­tative of this new class of pigments. It is a highly saturated medium shade red pigment with good hiding power, excellent fastness to organic solvents, and out­standing light and weather fastness. Because of its interesting properties, it has developed to […]

Many DPP pigments have been introduced to the market since the launch of the first DPP (C. I. Pigment Red 254) in 1986. The current[10] commercial DPP pig­ments range coloristically from orange to bluish reds, with particle sizes allowing for both opaque and transparent colorations and with specific forms and surface modifications for inks, paints, […]

Since pigment properties are dependent not only on the chemistry and solid-state properties of the pigment, but also to a large extent on the application in which the pigment is being used and how it is applied in a defined application, the inter­action between a pigment and a specific application media is of the utmost […]

Solid solution formation, where two or more components form one crystal lattice over a continuous range of compositions, is frequently observed in dye and pig­ment chemistry [49]. As a consequence, the X-ray diffraction (XRD) pattern of such a solid solution is the same or very similar to that of one of the components, the host. […]

DPP pigments with different particle sizes can be prepared by several methods. Classical conditioning (particle growth) in different solvents give rise to larger par­ticles with different morphology depending on the solvent characteristics [36]. Large particles can also be achieved directly in the synthesis through a heat treat­ment after the protonation of the intermediate pigment sodium […]

11.5.1 General Properties A broad spectrum of solid-state shades ranging from yellow to blue-violet have been accomplished by exchanging the substituents in the phenyl rings of the DPP chromophoric unit. Most DPP pigments display high color strength, the high smax values being additional testimony to this. The level of light — and weather fastness of […]

Nucleophilic transformation at the carbonyl group of DPPs without cleavage of the bicyclic ring system corresponding to a formal replacement of O by S, N, and C have also been investigated [5]. Early attempts at direct reaction of nucleophiles with diaryl-DPPs were foiled by the low reactivity of the carbonyl group. However, replacement of O […]

In analogy to other aromatic systems, nucleophilic aromatic substitution can also take place, depending on the substituents on the aromatic ring. For instance, 4,4′-dibromophenyl DPP 24 can react with amines at high temperatures in polar solvents to give 4,4′-diaminosubstituted DPP 26 as illustrated in Scheme 11.9 [32]. Scheme 11.8 11.4.3 W-Alkylation The alkylation of the […]

Diphenyl-DPP 2 was smoothly sulfonated to the corresponding disulfonic acid and acid salts 23 according to Scheme 11.7. Group II metal and ammonium salts of 23 proved to be thermally highly stable compounds and also useful pigment surface treating agents frequently warranting rheological improvement of DPP pigment dispersions in various paint media [29, 30]. 2 […]

A qualitative inspection of the diaryl-DPP molecule (Figure 11.7) reveals several centres of reactivity in the molecule. While the appropriately substituted phenyl rings should be capable of under­going diverse electrophilic and nucleophilic aromatic substitution reactions, the bicyclic lactam chromophore unit incorporates three different functional groups, namely double bonds, carbonyl, and NH groups, each of them […]