Лако-красочные материалы — производство

Phenolic resins are prepared by condensation of phenolic compounds with aldehyde, commonly formaldehyde. Phenol was initially pre­dominantly used to prepare phenolic resins, but subsequently, a greater variety of alkyl or aryl substituted phenols were explored to tailor the properties of resins by controlling functionality to meet diverse requirements of different coatings. An alkyl group substi- […]

Phenolic resins were among the first synthetic resins explored by the coating industry, initially used to modify properties of oil-based varnishes as a replacement for some natural hard resins. They are essentially solvent-soluble phenol-formaldehyde condensates with reactive methyllol groups. They are widely used as cross-linkers for thermosetting baking finishes, yielding films with excellent solvent and […]

The more significant volume of unsaturated polyester resins are used in fiberglass reinforced plastics, but they also find some applications in coatings and lining materials. The important characteristics of unsaturated polyester systems in coatings are high hardness, high gloss, rapid setting, low volatile content (reactive diluent) and high build capacity. Their low flexibility and high […]

Unsaturated polyester resins are low MW condensation polymers which are transformed to a cross-linked network via radical initia­ted polymerization. The double bonds in the backbone copolymerize with unsaturated monomer (reactive diluent) present in the system. During polymerization, relatively short low MW polyester chains are cross-linked by short bridges consisting of, on average, around two to […]

The chemistry involved in synthesis of unsaturated polyester resins is very similar to that in synthesis of saturated polyester resins, except that part of the dicarboxylic acid is replaced by diacids con­taining unsaturation, such as maleic anhydride and fumaric acid. In addition to this unsaturated acid, the predominant saturated acids used are phthalic anhydride, terephthalic […]

Unsaturated polyester resins are generally linear low MW polyes­ters having unsaturation (reactive double bonds) within their back­bone. They are supplied as a solution of polymerizable monomers (reactive diluents), most commonly in styrene.

Saturated polyesters can be designed for all types of application techniques, including air sprays, airless sprays, electrostatic liquid sprays, electrostatic powder sprays, roller coatings, and curtain coatings. Such coatings are offered as conventional solventbased, high-solid, waterbased systems as well as powder coatings. Due to the broad latitude of raw material selection, they can be desi­gned […]

Polyisocyanates are used with hydroxyl functional polyesters for ambient-cure two-component systems giving rise to films with an excellent combination of mechanical properties, solvent resistance, adhesion, durability and optical properties. More details can be found in Section 2.11. 2.4.6.1 Epoxy resins Epoxy resins are important curing agents for powder coatings based on acid functional polyester resins. […]

Amino resins are the most important curing agent for hydroxyl functional polyester resins to give baking finishes with adequate curing rate and very good mechanical and chemical resistance pro­perties. Mainly butylated melamine and urea formaldehyde resins are used, up to 40 % by weight of the total binder, depending upon the characteristics of the polyester […]

In contrast to alkyd resins, which have unsaturated fatty acid struc­tures capable of yielding a cross-linked network by air-drying via oxidative curing, polyesters need to be cured by a suitable external cross-linking agent to obtain the desired mechanical properties as well as durability and chemical resistance. Depending upon expected performance and application conditions, a range […]