Nanostructure analysis and discrimination of metallic pigments in automotive coating films for forensic investigation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K01298
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Social systems engineering/Safety system
• Research Institution: Kochi University
• Principal Investigator: Nishiwaki Yoshinori 高知大学, 教育研究部人文社会科学系教育学部門, 准教授 (50632585)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 科学捜査 / 自動車塗膜 / 異同識別 / X線分析 / マイクロビーム / 蛍光X線 / 微量元素 / メタリック顔料

Outline of Final Research Achievements

Discrimination of automobile paint fragments is important for clarifying traffic crimes. However, due to the miniaturization of evidence samples, FT-IR analysis, which is used to identify organic polymers that make up automotive coatings, often fails to discriminate between different types of polymers. In recent years, to improve the design, the number of coating films containing metallic pigments as a brightening agent is increasing. In this study, In this study, a new nondestructive discrimination method focused on the trace element components and nanostructures of metallic pigments was developed for the discrimination of automobile paint fragments by X-ray fluorescence using synchrotron radiation. It was found that this method enables us to discriminate automotive coatings far better than the conventional FT-IR database.

Free Research Field

法化学

Academic Significance and Societal Importance of the Research Achievements

従来、有機高分子によって識別していた自動車塗膜片を、放射光蛍光X線分析を用いて無機物であるメタリック顔料で行うことで、さらに詳細な異同識別を可能にした。安全・安心な社会の実現のため、表面近傍層だけでも車種特定が可能な新たな手法を開発することができた。本研究で開発した手法は多くの微細科学捜査試料の鑑定にも応用でき、社会の安心・安全に貢献できる。