The color of the adhesive is red so that the amount and location of it can be easily seen. And it becomes transparent after a while because it was developed by using a photochromic technology and its color disappears in response to light.
When Kokuyo S&T researched complaints about instant adhesives, it found that many users found it difficult to see the amount and location of applied adhesive because they are transparent. Therefore, the company developed the new adhesive, which has a color at the time of application but becomes transparent due to light.
Specifically, it obtained a patent for its technique of adding 0.05-5.0 mass percent of diarylethene-based photochromic compound to an adhesive containing cyanoacrylate.
The adhesive keeps its red color for about three minutes after being applied, making it easy to apply a proper amount of the adhesive to the right point. Then, it begins to gradually become transparent. It takes about 10 to 20 minutes for the adhesive to become completely transparent. The adhesive dries in several seconds to several tens of seconds after being applied.