The present disclosure provides a grease composition with improved water resistance and mechanical stability at high-temperatures, including: at least one base oil; a water insoluble thickener; and a low molecular weight thixotropic polyamide composition having molecular weight distribution characteristics meeting the requirement described by the relationship:
(
A
+
D
)
(
B
+
C
)
≥
0.05
where A=the % mass of the polyamide composition with a molecular weight greater than 1700 AMU; B=the % mass of the polyamide composition with a molecular weight between 1100 AMU and 1300 AMU; C=the % mass of the polyamide composition with a molecular weight between 700 AMU and 1000 AMU; and D=the % mass of the polyamide composition with a molecular weight of 600 AMU or lower (determined by GPC). The grease composition of the present disclosure provides a less than 50 penetration point change as determined by ASTM-D7342, a less than 10 mg weight loss as determined by ASTM-D4170, or both.
本公开提供了一种在高温下具有更好的耐
水性和机械稳定性的润滑脂组合物,其中包括:至少一种基础油;一种
水不溶性
增稠剂;以及一种低分子量触变性聚酰胺组合物,其分子量分布特性符合所述关系的要求:
(
A
+
D
)
(
B
+
C
)
≥
0.05
其中,A=分子量大于 1700
AMU 的聚酰胺组合物的质量百分比;B=分子量介于 1100
AMU 和 1300
AMU 之间的聚酰胺组合物的质量百分比;C=分子量介于 700
AMU 和 1000
AMU 之间的聚酰胺组合物的质量百分比;以及 D=分子量为 600
AMU 或更低的聚酰胺组合物的质量百分比(由
GPC 测定)。根据 ASTM-D7342 测定,本公开的润滑脂组合物的渗透点变化小于 50,根据 ASTM-
D4170 测定,重量损失小于 10 毫克,或两者兼有。