To provide a grease composition more excellent in heat resistance and lubricating performance and to provide a roller bearing reduced in seizure at high temperatures and in the occurrence of delamination caused by a microstructuralchange with whitening and being excellent also in rust-preventing performance. 耐熱性及び潤滑性能により優れたグリース組成物、並びに高温での焼き付きや、白色組織変化を伴う離性の発生が抑えられ、防錆性能にも優れる転がり軸受を提供する。 - 特許庁