Лако-красочные материалы — производство

X-ray diffraction (XRD) is a very useful characterization tool in today’s pigment industry. It is routinely used to verify RM quality and as a QC tool to control pro­duction. It can also be used to accurately measure lattice constants, study site — occupancies, measure crystallite size (when <100 nm), identify secondary phases, and quantify the […]

6.5.2.1 Particle Size Distributions The antiquated Fisher Sub-Sieve Sizer (FSSS) has been largely replaced by instru­ments that employ light scattering techniques, such as the Horiba LA910. These modern instruments measure particle size distributions (PSDs) over a size range of 0.02-1000 pm (microns or micrometers). Given proper dispersion and operat­ing techniques, very reproducible PSD results can […]

It has been largely assumed that the spectral absorptions of the DR pigments are due to d-d transitions of the dopant chromophores, specifically the Ni2+, Cr3+ and Mn2+ ions. However, it has also been proposed that the transition metal dopants have energy levels intermediate in the TiO2 band gap, and that the optical response is […]

The color properties of pigments are derived from their reflectance spectra over the visible wavelength range (400-700 nm). This will be discussed in Section 6.5.1.1. The near-infrared (NIR) (700-2500 nm) and part of the ultraviolet (UV) (>300 nm) regions are important because they affect the heat build-up and weath­ering of pigmented systems. They are briefly […]

Many of the properties of titanate pigments need to be controlled or monitored to give good, reproducible performance in the various applications. The properties to be discussed are: 1. spectral properties: visible, UV/NIR 2. physical properties: particle size distribution, XRD phase characterization, specific gravity, oil absorption, specific surface area, powder flow and dusting 3. chemical […]

Although the CrSbTi-DR pigments were originally designed for ceramic stain ap­plications, polymer applications dominate the field today. DR pigments can be used in almost any polymer, including vinyl (polyvinyl chloride), high tempera­ture engineering resins such as ABS and PPO, and fiber applications such as poly­propylene and nylon carpeting. MnSbTi DR pigments are used almost exclusively […]

Pseudobrookite, Fe2TiO5, is a stable structure that has even been observed as a decomposition product of overfired ZnFeTi spinel pigments. Despite this, it is dif­ficult to make clean versions of this pigment. The challenge in making high-quality pseudobrookite pigments (base formula Fe2TiO5) is obtaining complete reaction of the Fe2O3. This is a difficult reaction to […]

BaNiTi yellow priderite pigments (BaNiTi7O16) are generally synthesized from BaCO3, basic nickel carbonate, and TiO2 in a high temperature reaction. One of the goals of the synthesis is to minimize the level of acid-soluble Ba in the prod­uct. The manufacturers have various techniques to accomplish this task. One dif­ficulty is achieving complete BaCO3 decomposition while […]

Numerous reactions occur during the synthesis of DR pigments. Some of the important reactions in the formation of an NiSbTi pigment are shown in Scheme 6-1. Note that A represents the anatase TiO2 form and R represents the rutile TiO2 form. Sb2O3 + O2 —У Sb2O4 Sb2O4 + O2 —— Sb2O3 Sb2O3 melts Sb2Ox sublimes […]

Titanate pigments are ultimately formed by solid-state reactions at high tempera­tures. Whether the process involves wet or dry blending of the raw batch, raw batch milling, or precipitation of the raw batch, the pigments are only formed upon high temperature calcination. They are then milled to fine and narrow parti­cle size distributions. Other steps such […]