 | Walsroder NC-Chips are a specific form of nitrocellulose containing a plasticizer as their phlegmatizing or stabilizing agent. They are used where normal Walsroder Nitrocellulose cannot meet certain technical requirements. This includes:
- Production of printing inks where only ethyl acetate is to be the solvent used.
- Production of coatings for electrostatic spraying techniques. By using NC-Chips, solvents with a high flash point can be selected (ethanol and isopropanol have a flash point of around 12°C).
- Production of coatings that have a flash point above 55°C and are therefore not classed as flammable and do not require to be labelled as such. This is possible by selecting suitable with a high flash point.
- Use in two-pack polyurethane coatings. The expensive isocyanate component would react with the alcohol and the water in nitrocellulose damped with alcohol. By using NC-Chips it is possible to reduce the amount of isocyanate to obtain a certain cross-linking.
- If the package is opened and not properly reclosed, the phlegmatizing agent cannot evaporate in the case of NC-chips.
- Walsroder NC-Chips are highly suitable for producing coating systems where only one solvent is to be used.
Walsroder NC-Chips with ESO (epoxidized soybean oil) as their plasticizer are mainly used for wood and industrial coatings. A major application is two-pack polyurethane coatings. DBP (dibutyl phthalate), which was in widespread use in the past, is no longer on offer as it is not considered safe due to a possible hormonal effect. The European Union has issued new classification and labelling requirements for DBP. Coatings produced with more than 0.5 per cent DBP, for example, are required to be labelled with the skull and crossbones sign as from July 30, 2002 (28th adaptation of Directive 67/548/EEC). Tried-and-tested alternatives are citrates, phosphates and epoxidized soybean oil.
Dow Wolff Cellulosics had already begun to replace DBP and to discontinue its DBP-chips production prior to the EU’s decision to adopt the amended directive.
Walsroder NC-Chips with ATBC (acetyl tributyl citrate) are used predominantly for manufacturing printing inks containing the solvent ethyl acetate.
Information on the nitrocellulose grades available is given under the heading Product Range.
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