Лако-красочные материалы — производство

Corrosion inhibition by protective coatings can trace its origins to the earliest days of civilization. Red lead, as an anticorrosive pigment used in linseed oil coatings, estab­lished itself as the standard for corrosion inhibitive coatings [5.57]. Over the years, lead pigments have been proven to be outstanding anticorrosives, which perform par­ticularly well when used in […]

Anticorrosive pigments can affect the performance of protective coatings in several ways, such as • Prevention of underfilm corrosion • Protection of the metal substrate where the paint film is discontinued due to mechanical damage • Prevention of undercutting in damaged areas • Improvement of durability per unit of film thickness • Improvement of durability […]

Corrosion leads to deterioration of metals by chemical or electrochemical reactions resulting from exposure to weathering, moisture, chemicals or other agents in the environment into which they are placed [5.50]. Often corrosion is described as an electrochemically driven process of energy ex­change. Within this process, the metals, which were originally found in nature as ores, […]

5.2.1 Introduction Corrosion protection of metallic materials has, for a long time, been one of the key roles performed by organic coatings. The costs of damage incurred by corrosion of metals can be anything up to 5% of the gross domestic product in leading industrial nations [5.48]. Calculations over the past 50 years have shown […]

A particle size between 0.2 and 0.5 pm is preferred. High quality toners contain oxides with a narrow particle size distribution as demonstrated in Figures 5.6 and 5.7. Fig. 5.6 Magnetite pigment for use in laser printer toners. Fig. 5.7 Magnetite pigment for use in copier toners. The coercivity and remanent magnetization [5.46] of a […]

Black magnetite pigments are typically produced either by precipitation from iron salt solutions or by the Laux process. The production processes are described in detail in Section 3.1.1 (Table 3.2, especially Eqs. (3.10), (3.11) and (3.12)). 5.1.6.2

Many toners used in photocopiers and laser printers contain black magnetic iron oxide pigments (magnetite Fe3O4). The heart of a copier or laser printer is a cylinder coated with an organic photoconductor coating (OPC). Before the actual copying or printing process, the cylinder is electrostatically charged by a high-voltage corona, and then exposed to light […]

Barium ferrite is highly suitable for high-density digital recording, mainly because of its very small particle size and its very narrow switching field distribution. It also has a high anhysteretic susceptibility and is difficult to overwrite [5.38]. This is partly explained by positive interaction fields between particles in the coating layer [5.39]. The high anhysteretic […]

This process was developed by Toshiba [5.36]. The starting materials for barium ferrite production are dissolved in a borate glass melt. The molten material at ca. 1200 °C is quenched by pouring it onto rotating cold copper wheels to produce glass flakes. The flakes are then annealed to crystallize the ferrite in the glass matrix. […]

Iron (Fe(III)), barium, and the dopants are precipitated as their hydroxides and react with an excess of sodium hydroxide solution (up to 6 mol l-1) at 250-350 °C in an autoclave. This is generally followed by an annealing treatment at 750-800 °C to obtain products with the desired magnetic properties. Many variations of the process […]