To provide a grease composition capable of achieving a sufficient peeling life and a high temperature scorching life even under a high temperature, high speed and high loading condition and a roller bearing by using the same.
This grease composition contains a lubricating base oil, diurea compounds expressed by formulae (1) to (3) (wherein, R1 is a 7-12C aromatic ring-containing hydrocarbon group; R2 is a 6-15C divalent hydrocarbon group; and R3 is cyclohexyl or a 7-12C alkylcyclohexyl group), a naphthenic acid salt, succinic acid or its salts, and is characterized by that the containing ratios W1, W2 and W3 of the diurea compounds (1) to (3) satisfy expressions (4) and (5) and the containing ratios of the naphthenic acid salt, succinic acid or its salts are each 0.1-10 mass %. (4) 10≤W1+W2+W3≤35. (5) 0≤(W1+0.5×W2)/(W1+W2+W3)≤0.55.
NAKA MICHIHARU
SAKAMOTO KIYOMI
KINOSHITA HIROSHI
NIPPON OIL CORP
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