OBAYASHI CORPORATION has developed Scallop Paint, a water-based fluororesin paint using scallop shell powder, and begun applying it at 3 sites, including an experimental building at its technical research institute. The paint uses a biomass filler as a raw material to reduce waste and CO2 emissions.
OBAYASHI CORPORATION has developed Scallop Paint, an exterior water-based fluororesin paint containing a biomass filler made by pulverizing scallop shells. The company aims to make effective use of shells scheduled for disposal while expanding its lineup of environmentally considerate finishing materials. The paint has been applied at 3 locations in total, including Open Lab 3 at the company’s technical research institute.
#### Features of Scallop Paint By reusing scallop shells scheduled for disposal as a paint raw material, the product provides a biomass filler that can replace calcium carbonate. Its distinguishing feature is the use of shells, a marine by-product, instead of limestone-derived calcium carbonate used in conventional paints.
CO2 emissions during paint production are reported at 0.0879 kg-CO2/kg for the conventional limestone-derived product, compared with -0.44 kg-CO2/kg for scallop shells. Scallop Paint is expected to reduce emissions by incorporating 20% shell powder. Carbon fixed in the shells will also be incorporated into the coating and retained as part of the building over an extended period.
#### Verification of weather resistance and application results In an accelerated weathering test of approximately 5,500 hours, corresponding to conditions equivalent to about 30 years in an actual environment, Scallop Paint showed gloss retention and color difference ΔE equivalent to those of the conventional product without shell powder. Applications include Open Lab 3 (interior finishes), a 3D-printed bench at Yokohama Symphostage, and 3D-printed retaining walls at Shin-Marayama Dam.
Going forward, the company will advance commercialization and expand the range of applications, contributing to carbon neutrality and the circular economy.