Development of a safe full-color domestic-life colorant made of naturally occurring dyes

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H00963
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 08030:Family and consumer sciences, and culture and living-related
• Research Institution: Shizuoka University
• Principal Investigator: KOHNO Yoshiumi 静岡大学, 工学部, 准教授 (50334959)
• Co-Investigator(Kenkyū-buntansha): 福原 長寿 静岡大学, 工学部, 教授 (30199260) ; 冨田 靖正 静岡大学, 工学部, 准教授 (50303532)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 天然色素 / 粘土鉱物 / 有機修飾 / 安定化 / 耐久性 / 着色材料 / 三原色 / プラスチック

Outline of Final Research Achievements

From the viewpoint of safety, the shift to naturally occurring dyes for colorants is progressing. However, natural dyes are generally inferior in stability compared to synthetic products, and abundant natural dyes are limited and short to express full-color. In this study, the natural dye β-carotene was intercalated between clay layers to improve its stability. In addition, the condition of the intercalation was found to control the color of the intercalated β-carotene; the three primary colorants were developed, and full-color expression was realized. It was also shown that by including an appropriate stabilizer together with the dye between the layers, the oxidative deterioration of the dye molecules could be suppressed to show significantly improved durability. The β-carotene / clay composite materials thus obtained was heat-molded with various polymers, and it was confirmed that those composite materials could be used as a colorant for some plastics under proper conditions.

Free Research Field

無機有機複合体

Academic Significance and Societal Importance of the Research Achievements

通常では不安定な天然色素βカロテンを，天然に産出する粘土の層間に取り込み複合化することで，大幅な安定性の向上を実現した。複合化の条件によってβカロテンの色を黄色から赤色に調整できた。また，βカロテンに酸を作用させると青色化し，これも，同様に粘土との複合化により安定性を維持できた。以上より色の三原色を表現できる安定な色材としての複合体を得た。さらに，これらが一部のプラスチック素材の着色に使えることを示した。