Лако-красочные материалы — производство

In the course of the development of pigments for magnetic information storage, CrO2 was the first widely used pigment material that gave a higher recording density than Y-Fe2O3. In the field of audio recording this led to the IEC II standard or “chrome position”. 5.1.3.1

Pigments with a coercive field strength of 50-57 kA m-1 are used in videocassettes, high-biasaudiocassettes (chromium dioxide operating pointlEC II),andhigh-density floppy disks. Depending on the quality of the tape, the particle size varies between 0.2 and 0.4 pm (see Section 5.1.1, Table 5.1, and Figure 5.1). Pigments with a higher coercive field strength (ca. 70 […]

The iron oxide pigments described in Section 5.1.1 are either doped or coated with cobalt: 1. Body-doped pigments contain 2-5 wt.% cobalt that is uniformly distributed throughout the bulk of the pigment particles. It is either incorporated during pro­duction of the FeOOH precursor or precipitated as the hydroxide onto one of the intermediate products [5.13] […]

Cobalt-containing iron oxides form the largest proportion (ca. 71%) of magnetic pigments produced in 2002. Due to their high coercivity, they can be used as an al­ternative to chromium dioxide for the production ofvideotapes, high-bias audiotapes (CrO2 operating point, IEC II), and high-density floppy disks. 5.1.2.1

Magnetic pigments with very different morphological and magnetic properties that depend on the field of application and quality of the recording medium are used. The largest particles (length ca. 0.6 pm) are used in computer tapes. The noise level of the magnetic tape decreases with decreasing particle size. Fine pigments are therefore being used increasingly […]

The shape of the pigment particle is extremely important for ensuring good magnetic properties. Isometric iron oxide pigments produced by direct precipitation are seldom used. Since 1947, needle-shaped y-Fe2O3 pigments have been prepared with a length to width ratio of ca. 5 : 1 to 20 : 1 and a crystal length of 0.1-1 pm […]

5.1 Magnetic Pigments 5.1.1 Iron Oxide Pigments Ferrimagnetic iron oxide pigments are used in magnetic information storage sys­tems such as audio and videocassettes, floppy disks, hard disks, and computer tapes. Cobalt-free iron(III) oxide and non-stoichiometric mixed-phase pigments (so called Berthollide FeO%Fe2O3, with 0<x<1) have been used since the early days of magnetic tape technology. Currently, […]

Carbon black, with the exception of chemically treated and water dispersible carbon black grades, is appropriately andmost often disposed ofin landfills. Itis nontoxicand will not leach or release any constituents to the groundwater from a landfill. Carbon black, like activated carbon, has a very high surface area and a strong adsorptive capacity. Organic materials that […]

Carbon black is classified by the International Agency for Research on Cancer (IARC) as a Group 2B carcinogen (possibly carcinogenic to humans) based on “sufficient ev­idence” in animals and “inadequate evidence” in humans. Recent evidence indicates that the phenomenon of carcinogenicity in the rat lung is species-specific, resulting from persistent lung overload to carbon black […]

Carbon black should be stored in a clean, dry, uncontaminated area away from expo­sure to high temperatures, open flame sources and strong oxidizers. Since carbon black will adsorb moisture and chemical vapors, it should be stored in closed con­tainers. 4.8.4 Confined Space Entry Entry into bins, silos, rail tank cars, tank trucks, or other confined […]