a pigment of the imagination

Architect's memo 64: November 2000

Most people are aware that paint is a mixture of binders and pigments but it may come as a bit of a surprise that the surface area of these pigments in a litre of say white sheen paint can be over 5,000 square metres! To mix units, that is over one acre of interface between the mainly mineral pigments and the organic binders.

This interface between dissimilar materials can be a potential weakness in paint films, reducing cohesive strength and providing channels and corridors for the passage of water and dissolved salts.

Sheen paints require the presence of relatively coarse minerals to reduce the gloss of the film - often using particle sizes up to half the total thickness of the finished paint film. If such coarse particles are not tightly held by the binder; under the stress of scrubbing and cleaning down these particles can twist, turn and even pop out, leaving behind a damaged, burnished film.

Resene have, for some time, been under pressure to offer the tough enamel-like features of Resene Enamacryl and Resene Lustacryl in a low sheen finish but have been inhibited by the phenomena described above and the lack of an alternative pigment technology.

A series of fortunately timed events gave Resene the opportunity to have input into the design of a new pigment that has the potential to overcome the deficiencies of the traditional minerals.

The product is a cross-linked pure acrylic sphere, precisely sized to achieve optimum flatting. The perfectly spherical particles control not only gloss but also troublesome side-sheen.

By far their greatest technical benefit is however that they meld perfectly with the paint binder, blurring the distinction between pigment and binder. This translates into super tough, cleanable, burnish resistant surfaces.

An unexpected side benefit is that the 'ball bearing' like qualities of the spheres confer extreme ease of application and superior control when 'cutting-in'.

The potential for these spheres is wide including exterior durable flats and clears, 'flop' control in metallics, and a host of other uses. Supply however is still somewhat limited for this infant technology and what is available has been totally committed to Resene.

Our first offering of the technology is in a new product Resene SpaceCote. This product is designed for use in the toughest broadwall areas, such as corridors in schools, institutions and anywhere people gather indoors. It is almost certain however that its combination of toughness, silky smooth surface, and extreme ease of application will see it being used in areas where people simply want 'the best of the best'.

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