A preparation method of softwood lignin derivatives: US9347177B2 patent evaluation

This study, in the form of a patent evaluation, which is a technique for studying the information present within and attached to patents, describes the state of the art by introducing what has been patented in relation to softwood lignin derivatives. Inventors have described and claimed, through the US9347177B2 patent, a method for the preparation of derivatives of native lignin from softwood sources having a certain aliphatic hydroxyl content. The earliest priority date of the US9347177B2 patent was May 28^th, 2009, with 69 patent families and six filled jurisdictions. Based on patent classification, the invention covered by the patent concerns the processes of treating or compounding macromolecular substances and compositions of lignin-containing materials as well as lignin and products derived therefrom. To prove the concept of this invention, recovery of lignin derivatives has been carried out from three softwood species: hybrid spruce trees, radiata pine, and loblolly pine grown in Canada, Chile, and the United States, respectively. The inventors confirmed that choosing native lignin derivatives with a specific aliphatic hydroxyl content results in a product with more consistent antioxidant activity. Furthermore, another aspect of this invention related to the use of the softwood lignin derivatives comprises incorporating the softwood lignin derivatives into polymer compositions.