1.
synthetic resin; plastic
A class of man-made, resin-like materials produced by chemical synthesis from petroleum or other feedstocks — in ordinary Japanese, the technical-sounding equivalent of "plastic." Used on product labels, in materials science, and in regulatory language, often where the looser everyday word プラスチック would sound too casual.
Composed of 合成 (synthesis, combining) and 樹脂 (resin — originally the sticky exudate of trees). Although 樹脂 originally meant tree resin, in modern usage 合成樹脂 is essentially the formal Japanese word for plastic. Labels on household products and packaging often use it rather than プラスチック because it sounds more technical and precise.
Usage
- Appears on product labels such as material-composition notes: 材質：合成樹脂 (Material: plastic).
- Used in manufacturing, chemistry, and environmental contexts — e.g., discussions of plastic waste often use 合成樹脂 when sources cite statistics.
- In everyday conversation, speakers usually default to プラスチック or more specific names like ペットボトル (PET bottle).
Common collocations
- 合成樹脂製: made of synthetic resin
- 合成樹脂の容器: a synthetic-resin container
- 合成樹脂を使用する: to use synthetic resin
- 熱可塑性合成樹脂: thermoplastic resin
- 合成樹脂塗料: synthetic-resin paint
Similar words
- 樹脂: resin — the broader term, including both natural tree resin and synthetic resin
- プラスチック: plastic — the everyday loanword
- ビニール: vinyl — often used colloquially for plastic sheeting or bags
- ポリエチレン: polyethylene — a specific common plastic
- 合成繊維: synthetic fiber — a related category of man-made materials used for fabrics