Silicas for toner applications have to be well distributed over the surface of the toner particles. On an industrial scale, this is called the additive blending step. This step, which takes place after the raw toner has been produced, is when the silica is admixed. The silicas have to be broken down into smaller entities using as little energy as possible, and homogeneously envelop the toner particles. Only in this way will the desired property profile be achieved. To ensure the process runs smoothly, Piglosiewicz and his team are working on the dispersibility of the silica. It is a measure of how easily the additive can be transferred to the carrier particles. “And we can influence more than the dispersibility,” stresses Piglosiewicz. “We are able to customize the properties for the application by treating the surface with a wide range of silanes and siloxanes. It is also important to select precisely the right particle size and to adjust the particle size distribution.”
“You need to follow the market trend,” says Takayoshi Miyatani. He is the sales director at Clariant Japan and, together with his team, markets WACKER’s pyrogenic silica as well as other toner additives. The Japanese market continually demands new solutions to support manufacturers in meeting requirements for higher print speeds, increased image resolution and even cost and sustainability issues. Producers increasingly rely on toners with low glass transition points and smaller, more defined particle sizes and shapes. These powders can be fixed to the paper using less energy. The process is faster, and increasingly higher image resolutions can be achieved. If the composition of the toner changes, it may also be necessary to adapt the silica product. Piglosiewicz’s team in Burghausen needs to respond accordingly – in close consultation with Clariant and the toner producer.