Лако-красочные материалы — производство

Non-isocyanate, two pack acrylics are now used in a range of end use sectors, including heavy duty, transport, ACE (agricultural and construction equipment), VR (vehicle refinishing), plastics and general industrial enamels. The variety of application methods used in these sectors include: • brush • conventional spray • air assisted airless spray • airless spray • […]

The curing of a coating will not only depend on the chemistry, but also on the application in which it is utilised. In general, like 2K acrylic/isocyanate systems, the non-isocyanate acrylic must display good cure under ambient temperature and low bake (60-80°C) conditions. The minimum cure requirements, specific to the main end use sectors, have […]

Primary and secondary amine functional systems require a phenolic catalyst to react at ambient temperature and are characterised by a relatively slow cure. Tertiary amines are also used to crosslink epoxy functional acrylics. However, the reaction will only occur in the presence of a protonating agent, such as an acid or moisture. The slow cure […]

Anhydride systems are cured via the base catalysed reaction between a hydroxyl functional acrylic and an anhydride functional acrylic. The reaction is rapid at ambient temperatures. The free acid groups produced would be expected to form a rigidly crosslinked coating due to the high level of hydrogen bonding. The presence of these acid groups could […]

Ketimine systems cure by a two stage process. The first reaction involves a reaction of the ketimine with atmospheric moisture to produce a ketone and a highly reactive amine. The amine can then react with either an acetoacetate functional acrylic, or an unsaturated acrylic polymer. The cure reaction is extremely quick and would result in […]

The Michael reaction requires the use of a highly basic catalyst for the reaction to occur at room temperature. Initial research utilised strong inorganic bases to catalyse this reaction. However, due to the retention of these bases in the final film, very poor water resistance characteristics were observed. Recently, these catalysts have been replaced by […]

(i) Carboxy/epoxy The carboxy/epoxy system displays a very fast lacquer type dry but, in comparison to a 2 pack polyurethane, relatively slow through cure. Tertiary amines can be used to enhance the cure of the coating. However, careful selection of the catalyst is critical since some amines can also make the coating water sensitive. There […]

1. Curing Two pack non-isocyanate acrylics, due to their ability to cure at ambient temperatures, are normally used where the properties of a stoved finish are desired but it is not possible to heat cure the article. This could be due to the sensitivity of the substrate to heat, the size of the component to […]

Due to the complex nature of the chemistries utilised in the range of non-isocyanate acrylics, the catalysts utilised are not only specific to the chemistry, but also to the particular manufacturing system. Readers should consult the manufacturer’s recommendations for catalysts as, in general, these additives can display more adverse affects than benefits if the wrong […]

Non-isocyanate acrylics do, in general, display excellent flow when applied direct from the gun. Additives such as silicone oil or polysiloxane derivative have been shown to enhance the final finish in terms of flow and gloss. Care should be taken in the selection of additives to avoid adversely affecting the intercoat adhesion. Taking into consideration […]