Analysis of patents on the recycling technologies for the used polystyrene

In this paper the world wide patents on the recycle of used polystyrene were inspected. The trends and directions of on going and future technologies on this matter were analyzed. The range of search was limited in the open patents and in DB of U.S.A.(USPTO, DELPHION), Japan(PAJ), Europe(EPO), and Korea(KIPRIS). For the search condition the keyword, polystyrene or PS, and IPC classification, B29-017 and C08J-011 were used. The total of 534 cases was selected and analyzed according to years, countries, companies, and technologies.