want a good raincoat - tough!!

Architect's memo 82: February 2006

This series of memos normally endeavours to address interesting or topical areas of paint or substrate technology and generally keep at arms length from the commercial aspects of the business. This one, however, is going to veer very close to the commercial and pay a tribute to a remarkable product - Resene X-200.

Resene X-200 has been around a long time and is probably protecting more high-rise buildings in New Zealand than any other product. When asked to what I ascribe its longevity and continued success, the word 'toughness' is the one that springs to mind as being the most appropriate.

My dictionary variously describes 'tough' as durable, hard to break, hardy, unyielding and stubborn - take your pick, they all work!

Resene X-200 was first launched in February 1982 when seven coat, bituminous-based waterproofing systems were still king and the coatings industry was starting to experiment with soft, highly extensible (but not elastic) materials to try and control cracking in buildings.

We at Resene believed that a building was never going to be held together by coatings but that there was a need for a truly high solids coating that could be applied by brush, roller or spray, provide a good water barrier while providing long-term decorative appearance.

It is well known that acrylic resins exist in the wet paint as small spheres. It is also obvious that if you fill a big box full of, say, soccer balls, that there will be lots of spaces in between the balls. Even if the balls are somewhat soft and can be deformed, some spaces will exist. Our simple idea was to take another ball, comparatively the size of a squash ball and mix these in with the soccer balls to 'plug up' all of the minute holes in the film.

This smaller phase also increased the number of points of contact so that the film could 'glue' itself together even better.

Using this smaller phase also allowed us to increase the volume solids as areas that were occupied by water (or subsequently air) were now filled with polymer.

There was also the potential, which was employed, to use different chemistries on each of the phases, so that long-term crosslinking could occur - further strengthening the film.

There has, of course, been significant new developments in paint binders since 1982, the emphasis of which has been to reduce VOCs. This has generally necessitated making the polymers somewhat softer and, while they are meeting the VOC challenge superbly, they don't have, well, the 'toughness' of some of the older systems.

Introducing a two coat system to challenge the existing multi-coat systems was indeed a challenge! To give the product impetus, we gave it an outrageous guarantee - if it failed at any time within the warranted 10 year period, we would fully reinstate it, gratis. We were very confident and it was not misplaced - there has not been a single justifiable claim against the product in its long history. A Resene X-200 warranty comes complete with specification and building inspections providing assurance that the coating is applied to last.

The formulation exists today virtually identical to the day it was launched with elements of new technology bound into the original formulation. Resene X-200, I take my hat off to you - you're a tough old coating.

The Resene X-200 10 year warranty is agreed in writing at the time of specification and cannot be requested once the system has been applied.

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