硫化 りゅうか処理 しょりゴムではありませんでした
ryūkashorigomudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 硫化処理ゴム

1. Was not sulfur-treated rubber.; Was not vulcanized rubber.

Past/Perfective
Negative
Polite
Formal Register