A mixed powder for powder metallurgy comprises: an iron-based powder; and a lubricant, wherein the lubricant consists of a low-melting-point lubricant having a melting point of 86° C. or less and a high-melting-point lubricant having a melting point of more than 86° C., the low-melting-point lubricant has at least one of an amide group, an ester group, an amino group, and a carboxyl group, a ratio R1 of the low-melting-point lubricant to whole of the lubricant is 5 mass % or more and less than 90 mass %, a ratio R2 of a mass of a free lubricant to a mass of a binding lubricant is 0 or more and 15 or less, and an amount R3 of the low-melting-point lubricant contained as the free lubricant is less than 0.10 parts by mass with respect to 100 parts by mass of the iron-based powder.

A mixed powder for powder metallurgy comprises: an iron-based powder; and a lubricant, wherein the lubricant consists of a low-melting-point lubricant having a melting point of 86° C. or less and a high-melting-point lubricant having a melting point of more than 86° C., the low-melting-point lubricant has at least one of an amide group, an ester group, an amino group, and a carboxyl group, a ratio R1 of the low-melting-point lubricant to whole of the lubricant is 5 mass % or more and less than 90 mass %, a ratio R2 of a mass of a free lubricant to a mass of a binding lubricant is 0 or more and 15 or less, and an amount R3 of the low-melting-point lubricant contained as the free lubricant is less than 0.10 parts by mass with respect to 100 parts by mass of the iron-based powder.

Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), and a tricyclic liquid crystal compound of formula (2), and having a mixing mass ratio of the bicyclic liquid crystal compound and tricyclic liquid crystal compound of 95:5 to 15:85. The composition is suitable for use in a clean environment, under a high vacuum, under high temperature and a bearing.

##STR00001##

R.sup.1 and R.sup.2 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR

##STR00002##

R.sup.11 and R.sup.21 are the same or different from each other, and each is —OR. R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is hydrogen or —OR. R is a linear or branched C.sub.nH.sub.2n+1, 1≤n≤20 and R′ is methyl or ethyl.

Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), and a tricyclic liquid crystal compound of formula (2), and having a mixing mass ratio of the bicyclic liquid crystal compound and tricyclic liquid crystal compound of 95:5 to 15:85. The composition is suitable for use in a clean environment, under a high vacuum, under high temperature and a bearing. ##STR00001##
R.sup.1 and R.sup.2 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR ##STR00002##
R.sup.11 and R.sup.21 are the same or different from each other, and each is —OR. R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is hydrogen or —OR. R is a linear or branched C.sub.nH.sub.2n+1, 1≤n≤20 and R′ is methyl or ethyl.

This is to provide an electrically-conductive lubricant having characteristics in combination that it shows liquid crystallinity in a wide temperature range, retains low dynamic friction coefficient, has electrical-conductivity, has almost no loss due to evaporation, decomposition and the like, has a clean appearance, and emits fluorescence, and can find deterioration or leakage immediately.

This electrically-conductive lubricant comprises at least one kind of the compound (1) represented by the formula (1):

##STR00001##

[wherein, R.sup.11 and R.sup.21 are the same or different from each other, and each is hydrogen or a group —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR (R is a linear or branched C.sub.nH.sub.2n+1, 4≤n≤12, and R′ is methyl or ethyl), and R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is a group —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR (R is a linear or branched C.sub.nH.sub.2n+1, 4≤n≤12, and R′ is methyl or ethyl)].

An organogel including a base fluid, cetyl alcohol, and a gelling agent provided in an amount to cause the fluid to change from a liquid state to a gelled state at temperatures below at least 25° C. A nanofluid including an organogel and a nanoparticle component which permits the nanofluid to change from a liquid state to a gelled state at temperatures below at least 25° C., the gelled state helping to maintain the nanoparticle component suspended throughout the base fluid; and a method for preparing a gelled nanofluid.

An organogel including a base fluid, cetyl alcohol, and a gelling agent provided in an amount to cause the fluid to change from a liquid state to a gelled state at temperatures below at least 25° C. A nanofluid including an organogel and a nanoparticle component which permits the nanofluid to change from a liquid state to a gelled state at temperatures below at least 25° C., the gelled state helping to maintain the nanoparticle component suspended throughout the base fluid; and a method for preparing a gelled nanofluid.

A grease composition for a constant-velocity joint includes a mineral oil, a thickener, a molybdenum dithiocarbamate, a potassium borate hydrate, and a zinc dialkyldithiophosphate, wherein a content of the molybdenum dithiocarbamate is 1.2% by mass or more and 8% by mass or less, a content of the zinc dialkyldithiophosphate is 0.3% by mass or more and 2.0% by mass or less, and a content of the potassium borate hydrate is 0.28% by mass or more and 1.9% by mass or less, and wherein a mass ratio of the content of the molybdenum dithiocarbamate to the content of the potassium borate hydrate (molybdenum dithiocarbamate/potassium borate hydrate) is 2 or more and 13 or less, and a mass ratio of the content of the zinc dialkyldithiophosphate to the content of the potassium borate hydrate (zinc dialkyldithiophosphate/potassium borate hydrate) is 0.5 or more and 3.6 or less.

A grease composition for a constant-velocity joint includes a mineral oil, a thickener, a molybdenum dithiocarbamate, a potassium borate hydrate, and a zinc dialkyldithiophosphate, wherein a content of the molybdenum dithiocarbamate is 1.2% by mass or more and 8% by mass or less, a content of the zinc dialkyldithiophosphate is 0.3% by mass or more and 2.0% by mass or less, and a content of the potassium borate hydrate is 0.28% by mass or more and 1.9% by mass or less, and wherein a mass ratio of the content of the molybdenum dithiocarbamate to the content of the potassium borate hydrate (molybdenum dithiocarbamate/potassium borate hydrate) is 2 or more and 13 or less, and a mass ratio of the content of the zinc dialkyldithiophosphate to the content of the potassium borate hydrate (zinc dialkyldithiophosphate/potassium borate hydrate) is 0.5 or more and 3.6 or less.

Provided is a lubricant composition including a bicyclic liquid crystal of formula (1), tricyclic liquid crystal compounds of formula (2), and formula (3). The composition is suitable for use in a clean environment, under a high vacuum, under high temperature and a bearing.

##STR00001##

R.sup.1 and R.sup.2 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR.

##STR00002##

R.sup.11 and R.sup.21 are the same or different from each other, and each is —OR. R.sup.12, R.sup.13, R.sup.22 and R.sup.23 are the same or different from each other, and each is hydrogen or a group —OR.

##STR00003##

R.sup.31 and R.sup.41 are the same or different from each other, and each is —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR. R.sup.32, R.sup.33, R.sup.42, and R.sup.43 are the same or different from each other, and each is hydrogen or —OCH.sub.2CH.sub.2CH(R′)CH.sub.2CH.sub.2OR. R is a linear or branched C.sub.nH.sub.2n+1, 1≤n≤20, and R′ is methyl or ethyl.