JPH0245596A - Heat-resistant synthetic lubricating oil - Google Patents

Abstract

PURPOSE:To obtain a novel synthetic lubricating oil having high viscosity index, stability to thermal oxidation, excellent rubber swelling properties and excellent compatibility with other lubricating oils and additives consisting essentially of an aromatic ester having a specific structure. CONSTITUTION:The aimed lubricating oil containing an aromatic ester shown by the formula (R2 and R2 are H or 1-10C alkyl; R3 and R4 are 2-30C acyl; X and Y are 1-5C alkyl; n and p are 0-4; A and B are 2-4C alkylene; m is 0-30 integer). Esters wherein R1 and R2 are H or 1-4C alkyl, R3 and R4 are 4-24C branched acyl or 1-12C saturated straight-chain acyl, X and Y are t-butyl and m is 1-5 are preferable as the above-mentioned ester. The lubricating oil is useful as hydraulic oil, metal processing oil, compression member oil, grease base oil, heating medium oil, engine oil, turbine oil, turbocharger oil, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a new synthetic lubricating oil, and more specifically to a thermally stable and oxidatively stable lubricating oil whose main component is an aromatic ester having a specific structure. This relates to lubricating oil that has excellent properties.

[Problems to be solved by conventional techniques and inventions] In recent years,
Requests for extension of oil change period and energy saving,
As the performance of mechanical equipment increases, the performance required of lubricating oils is also becoming more severe, and in particular, there is a strong demand for lubricating oils with particularly excellent thermal stability and oxidation stability. It has become to.

In order to meet these demands, polyα-olefin,
Polybutenes, polyalkylene glycols, alkylbenzenes, alkylnaphthalenes, aliphatic diesters, polyol esters, phosphoric esters, etc. have been developed and are used in fields where oxidative stability and thermal stability are required. For example, polyα-olefin is used in automobile engine oil, gear oil, grease base oil, etc., polybutene is used in 2-cycle engine oil, compressor oil, etc., polyalkylene glycol is used in brake oil, hydraulic oil, etc., and alkylbenzene is used in electrical insulation oil. , refrigerating machine oil, etc., aliphatic esters are used in jet engine oils, automobile engine oils, hydraulic oils, grease base oils, precision machine oils, etc., and phosphoric esters are used in hydraulic oils, etc.

However, these synthetic lubricants cannot withstand use under harsher conditions, and silicone-based synthetic lubricants, polyphenyl ethers, fluorine synthetic lubricants, etc. are also used, but they are all very expensive and difficult to use. Limited scope.

Under the above-mentioned circumstances, the present invention aims to provide an inexpensive synthetic lubricating oil with excellent thermal oxidative stability.

Means for Solving Problem C] As a result of intensive research to achieve the above object, the present inventors discovered that an aromatic ester having a specific structure could achieve the object, and completed the present invention. I ended up doing it.

That is, the present invention is based on the general formula (I) (wherein L and Rz are hydrogen or an alkyl group having 1 to 10 carbon atoms, R, R4 is an acyl group having 2 to 30 carbon atoms, X, Y
represents an alkyl group having I to 5 carbon atoms, nl9 represents an integer of 0 to 4, and when n and/or p are 2 or more, Xs or Ys may be the same or different. Also,
A, B are alkylene groups having 2 to 4 carbon atoms, L, III
represents an integer from 0 to 30. ) It provides a heat-resistant synthetic lubricating oil whose vF@ indicates that it contains an aromatic ester represented by the following formula.

In the above formula (I), I? ,, 172 represents hydrogen or an alkyl group having 1 to 10 carbon atoms, but specifically R +
, Rz are hydrogen, or groups such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, octyl, and decyl.

Particularly preferred is hydrogen or an alkyl group having 1 to 4 carbon atoms.

R3, R, represents an acyl group having 2 to 30 carbon atoms, specifically saturated straight chain fatty acids such as acetic acid, propionic acid, caproic acid, heptanoic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, Lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, branched fatty acids 2-ethyl pencunic acid, 2-methylhexanoic acid, 2-
Derived from ethylhexanoic acid, isooctanoic acid, isononanoic acid, isopalmitic acid, isostearic acid, 2-hebutylundecanoic acid, unsaturated fatty acids oleic acid, linoleic acid, erucic acid, aromatic carboxylic acid benzoic acid, etc. Examples include acyl groups. From the viewpoint of low-temperature fluidity, a branched acyl group having 4 to 24 carbon atoms or a saturated linear acyl group having 1 to 12 carbon atoms is preferred.

When using a saturated linear acyl group having 13 or more carbon atoms, it is desirable to use it together with an acyl group having a branched structure.

X and Y represent an alkyl group having 1 to 5 carbon atoms, specifically groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 5ec-butyl, tert7'tyl, pentyl, 5ec-pentyl, etc. Can be mentioned. Among these, particularly preferred is tert-butyl group,
Excellent in terms of thermal stability and oxidative stability. Also, n,
p represents an integer of 0 to 4, but when n and/or ρ is 2 or more, Xs or Ys may be the same or different.

In addition, A and B are alkylene groups having 2 to 4 carbon atoms, 1+
m represents an integer of 0 to 30, and those in which 1m is 1 to 5 are particularly excellent in terms of thermal stability, oxidation stability, and manufacturing cost. In addition, when L+'' is 2 to 30, (OA)L, (B
O), each OA in the % chain, 130 may be the same or different.

The aromatic ester represented by the above general formula (I) can be produced, for example, as follows.

a) 2.6-tert-butylphenol, 2
-tert-butyl-5-methylphenol, 2ter
Alkylphenols such as t-butyl-5-ethylphenol, 2,3゜6-drimethylphenol, 2,6-diisopropylphenol, 2.6-dimethylphenol, 2.5-diethylphenol, or phenols 2 moles of the selected one or two or more of them are added to formaldehyde, acetaldehyde, butanal,
A bisphenol compound is obtained by dehydration condensation with an aldehyde such as octanal or a ketone such as acetone, methyl ethyl ketone, dibutyl ketone, or pentyl methyl ketone in the presence of IIcI or the like.

b) For 1 mol of the bisphenol compound obtained in a), 1 to 60 mol of an alkylene oxide having 2 to 4 carbon atoms is added at a temperature of 100 to 180°C using an alkali catalyst such as Na011. The reaction yields a bisphenol derivative alkylene oxide adduct.

C) Next, 1 mole of the bisphenol M conductor alkylene oxide adduct obtained in b) and 2 moles of carboxylic acid are reacted by a known esterification reaction method to obtain the aromatic ester of the present invention.

The method for synthesizing the aromatic ester of the present invention is not limited to the above method.

More specific examples of the compounds of the present invention include the following esters.

Namely, 4,4''-methylene diphenol polyoxyethylenide cicapric acid ester, 4,4'-methylene diphenol polyoxypropylenide stearate 2-methylhexanoate, 4,4'-methylene diphenol polyoxyethylene Polyoxypropylenide dilauric acid ester, 4.4''-methylene diphenol polyoxybutylenide di-2-ethylhexanoate, 4.4°-('2'', 2''-propylidene) diphenol polyoxyethylenide dilaurate Benzoic acid ester, 4
．． 4"-(2", 2"-propylidene) diphenol polyoxypropylenide myristate 2-methylhexanoate, 4.4"-(2', 2"'-propylidene) diphenol polyoxyethylene polyoxypropylene compound capric acid caprylic acid ester, 4,4“-
(2'', 2#-propylidene) diphenol polyoxybutylenide di-2-hebutyl undecanoate, 4
, 4゛-butylene diphenol polyoxyethylenide caproic acid caprylate ester, 4,4゛-butylene diphenol polyoxypropylenide di-2,4-dinotylhexanoate ester, 4.4''-butylene diphenol polyoxy Ethylene polyoxypropylenide 2-hebutyl undecanoic acid stearate, 4.4”-
Butylene diphenol polyoxybutylenide balmitic acid 2-butyloctanoic acid ester, 4.4'-(2”
22”-butylene) diphenol polyoxyethylenide di2-hexyl decanoate, 4.4”=(2”
2"-butylene) diphenol polyoxypropylenide 2.4-dimethylhexanoic acid caprylate, 4.4'-(2", 2"-butylene) diphenol polyoxyethylene polyoxypropylenide di2-pentylnonanoic acid Ester, 4,4"-(2".

2"-butylene) diphenol polyoxybutylenide caprilate, 4.4"-(3"3" hexylene) diphenol polyoxyethylenide di2-methylhexanoate, 4,4(3", 3") -hexylene) diphenol polyoxypropylenide diundecanoate ester, 4,4'-(3'', 3'-hexylene) diphenol polyoxyethylene polyoxypropylenate di2-ethylhexanoate, 4,4''-
(3"3"-hexylene) diphenol polyoxybutylenide di2-octyldodecanoate, 4.4'
-(5'',5''-hebutylene)diphenol polyoxyethylenide benzoic acid caproic acid ester, 4.4°-
(5'', 5''-hebutylene) diphenol polyoxypropylenide dihebutanoic acid ester, 4.4'-(5''
, 5″-hebutylene) diphenol polyoxyethylene polyoxypropylenide cicapric acid ester, 4.
4'-(5",5"hebutylene)diphenol polyoxybutylenide 2-ethylhexanoic acid lauric acid ester, 4,4-methylene-bis2,6-diter t-butylphenol polyoxyethylenide di2- Decyltetradecanoic acid ester, 4,4゛-methylenebis2,6
-di-tert-butylphenol polyoxypropylenide dinonanoic acid ester, 4,4'-methylenebis2
．． 6-di-tert-butylphenol polyoxyethylene polyoxypropylenide 2-methylhexanoic acid hebutanoate, 44'-methylene-bis2,6-di-tert-butylphenol polyoxybutylenide capric acid laurate, 4 ,4"-(2',
2"-propylidene)-bis2,6-di-tert-butylphenol polyoxyethylenide caproic acid ester, 4.4'-(2",2n-propylidene)-bis2,6-di-tert-butylphenol polyoxy Propylenated di-2-butyl octanoic acid ester, 4.
4゜(2'',2''-propylidene)-bis2,6-dit
er t Butylphenol polyoxyethylene polyoxypropylenide di2-methylhexanoate, 4
．． 4= (2”, 2”-propylidene)-bis2,6
-di-tert-butylphenol polyoxybutylated diundecanoic acid ester, 4.4butylene-bis2
, 6-di-tert-butylphenol polyoxyethylenide di-2-ethylhexanoate, 4,4"-
Butylene-bis-2,6-di-tert-butylphenol polyoxypropylenide di-2-octyldodecanoic acid ester, 4,4-butylene-bis-2,6-di-tert
-Butylphenol polyoxyethylene polyoxyethylene propylenide benzoic acid caproate ester, 4.4"-butylene-bis2.6-diter t-butylphenol polyoxybutylenide dihebutanoate ester, 4.4
'-(2'', 2'-butylene)-bis2,6-dite
r tButylphenol polyoxyethylenide caproic acid caprylate ester, 4,4''-(2'',2''butylene)-bis2,6-di-tert-butylphenol polyoxypropylenide di2-hebutylundecanoate ester, 4 .4"-(2", 2"-butylene)-bis2
, 6-diter L-butylphenol polyoxyethylene polyoxypropylenide capric acid caprylic acid ester, 4.4'-(2'2'-butylene)-bis2,
6-di-tert-butylphenol polyoxybutylenide myristate 2-methylhexanoate, 4.
4'-(3''3''-hexylene)-bis2,6-dite
r t-Butylphenol polyoxyethylenide dibenzoate ester, 4,4''-(3', 3''-hexylene)-bis2,6-di-tert-butylphenol polyoxypropylenide di-2-ethylhexanoate ester, 4 .4°-(3''3''-hexylene)-bis2,6 di-tert-butylphenol polyoxyethylene polyoxypropylenide di-2-butyl octanoic acid ester,
4.4'-(3', 3'-hexylene)-bis26-
Di-tert-butylphenol polyoxybutylenide capric acid laurate, 4,4゛(5'', 5''-hebutylene)-bis2,6-di-Lert-butylphenol polyoxyethylenide capric acid laurate,
4.4'-(5",5"hebutylene)-bis2,6-di-tert-butylphenol polyoxypropylenide 2-methylhexanoic acid hebutanoic acid ester, 4,4°-
(5'',5''-hebutylene)-bis2,6-diter
t-Butylphenol polyoxyethylene polyoxypropylenide dinonanoate ester, 4.4'-(5",
5"-hebutylene)-bis2,6-diLert-butylphenol polyoxybutylenide di2-decyltetradecanoic acid ester, 4,4"-methylene-bis2-ter
t-Butyl-5-methylphenol polyoxyethylenide 2-ethylhexanoic acid laurate, 4,4
゛-Methylene-bis-2-tert-butyl-5-methylphenol polyoxypropylenide caprinic acid ester, 4,4-methylene-bis-2-tert-butyl-5-methylphenol polyoxyethylene polyoxypropylenide stearic acid 2,4-dimethylhexanoic acid ester, 4.4'-methylene-bis-2-jertbutyl-5-methylphenol polyoxybutylenide dilauric acid ester, 4.4'-(2".

2"-propylidene)-bis2-tert-butyl-5
-Methylphenol polyoxyethylated di-2,4-
Dimethylhexanoate, 4.4'-(2'', 2''
-propylidene)-bis2-tert-butyl-5-methylphenol polyoxypropylenide 2-hebutylundecanoic acid stearate, 4.4'-(2”
, 2″-propylidene)-bis2-tert-butyl-
5-Methylphenol polyoxyethylene polyoxypropylenide Balmitic acid 2-butyl octanoate, 4.4'-(2", 2"-propylidene)-bis2 tert-butyl-5-methylphenol polyoxybutylenide 2-hexyl decanoic acid ester, 4
．． 4'-(2'',2''-propylidene)-bis2-te
rt-Butyl-5-methylphenol polyoxyethylenide 2,4-dimethylhexanoic acid caprylate, 4,4゛-butylene-bis-2-tert-butyl-5-
Methylphenol polyoxypropylenide di-2-pentyl nonanoate ester, 44'-butylene-bis2-mert-butyl-5-methylphenol polyoxyethylene polyoxypropylenide cycaprylate ester, 4
．． 4-butylene-bis-2-tert-butyl-5-methylphenol polyoxybutylenide cicapric acid ester, 4.4'-(2'',2'-butylene)bis-2-te
rt-Butyl-5-methylphenol polyoxyethylenide di-2-butyl octanoic acid ester, 4,4°-(
2", 2'-butylene)-bis-2-tert-butyl-5-methylphenol polyoxypropylenide caproic acid ester, 4.4'-(2", 2'-butylene)-bis-2-tert-butyl-5 -Methylphenol polyoxyethylene polyoxypropylenide capric acid laurate, 4.4'-(2'',2''-butylene)-bis2-tert-butyl-5-methylphenol polyoxybutylenide 2-methylhexanoic acid Hebutanoic acid ester, 4,4°-(3”,3”-hexylene)
-bis2-tart-butyl-5-methylphenol polyoxyethylenide dinonanoic acid ester, 4,4°-
(3″,3″-hexylene)bis2-LerL-butyl-5-methylphenol polyoxypropylenide di2
-decyltetradecanoic acid ester, 4.4'-(3",
3''-hexylene)bis2-tert-butyl-5-methylphenolpolyoxyethylenepolyoxypropylenide 2-ethylhexanoic acid laurate,4.
4'-(3'',3''-hexylene)-bis2-tert
Butyl-5-methylphenol polyoxybutylenide caprinic acid ester 1,1.4'-(5',5''hebutylene)-bis2-tert-butyl-5-methylphenol polyoxyethylenide dihebutanoic acid ester,
4.4'-(5'',5''-hebutylene)-bis2-te
rt-Butyl-5-methylphenol polyoxypropylenide benzoic acid caproic acid ester, 4.4'-(5
",5"-hebutylene)-bis2 tert-butyl-5-methylphenol polyoxyethylene polyoxypropylenide di2-octyldodecanoate, 4
,4(5'', 5''-hebutylene)-bis2-tert
-Butyl-5-methylphenol polyoxybutylenide diundecanoic acid ester, 4,4゛-methylenebis2
tert-butyl-5-ethylphenol polyoxyethylenide di2-methylhexanoate, 4,
4'-methylene-bis-2-tert-butyl-5-ethylphenol polyoxypropylenide cacryl ester, 4.4'-methylene-bis-2-tert-butyl-5-ethylphenol polyoxyethylene polyoxypropylenide di2 -pentyl nonanoic acid ester, 44
°-Methylene-bis2-tert-butyl-5-ethylphenol polyoxybutylenide 2-methylhexanoic acid caprylate, 4.4"-(2"2"-propylidene)-bis2-tert-butyl 5-ethyl Phenol polyoxyethylenide di-2-hexyl decanoate, 4.4'-(2''2''-propylidene)-bis2-tert-butyl 5-ethylphenol polyoxypropylenide palmitic acid 2-butyl octanoate, 4.4'-(2'', 2''-propylidene)-
bis2-terLbutyl-5-ethylphenolpolyoxyethylenepolyoxypropylenide 2-hebutylundecanoic acid stearate, 4.4'-(2"2
"-propylidene)-bis2-tert-butyl-5-ethylphenol polyoxybutyrenated di2-methylhexanoic acid ester, 4,4°~butylene-bis2t
ert-7' thyl-5-ethylphenol polyoxyethylenide caproic acid caprylic acid ester, 484゛-
Butylene-bis-2-tert-butyl-5-ethylphenol polyoxypropylenide di-2-hebutyl undecanoate, 4,4'-butylene-bis2te
rt-butyl 5-ethylphenol polyoxyethylene polyoxypropylenide capric acid caprylate ester, 4,4°-butylene-bis2tert-butyl-5-ethylphenol polyoxybutylenide myristic acid 2-methylhexanoate ester, 4.4'-(2
", 2"-butylene)-bis2-tert-butyl-
5-Ethylphenol polyoxyethylenide di-2-ethylhexanoate, 4.4=(2'',2''-butylene)-bis2-tertbutyl-5-ethylphenol polyoxypropylenide dibenzoate ester, 4 ．．
4'-(2".

2''-butylene)-bis2 tert-butyl-5 ethylphenol polyoxyethylene polyoxypropylenide di2-ethylhexanoate, 4.4'-(
2",2"-butylene)-bis2-tert-butyl-
5-Ethylphenol polyoxybutylenide dilauric acid ester, 4,4"-(3",3"-hexylene)
-bis2-tert-butyl-5-ethylphenol polyoxyethylenide stearic acid 2,4-dimethylhexanoate, 4,4°-(3”, 3”-hexylene)-bis2-tert-7’thyl -5-Ethylphenol polyoxypropylenide caprinic acid ester, 4.4″-(3″, 3″-hexylene)-bis2-
tert-butyl-5-ethylphenol polyoxyethylene polyoxypropylenide di-2-methylhexanoate, 4.4'-(3'',3''-hexylene)-bis2-tert-butyl-5-ethylphenol polyoxy Butyrenated di-2-pentyl nonanoic acid ester, 4
．． 4°-(5”,5”-hebutylene)-bis2te
rt-Butyl-5-ethylphenol polyoxyethylenide 2,4-dimethylhexanoic acid caprylate, 4,4"-(5").

5''-hebutylene)-bis2-tert-butyl-5ethylphenol polyoxypropylenide di2-.\xyldecanoic acid ester, 4,4'=(5'.

5″-hebutylene)-bis2-tert-butyl-5ethylphenol polyoxyethylene polyoxypropylenide cycaprylic acid ester, 44′-(5″, 5″
-hebutylene)-bis2-tert-butyl-5-ethylphenol polyoxybutylenide palmitic acid 2-
Butyloctanoic acid ester, 4,4-methylene-bis2
, 3.6-1-limethylphenol polyoxyethylenide + JIyJ2-hebutylundecanoic acid stearate, 4゜4'-methylene-bis2,3.6-)limethylphenol polyoxypropylenide di-2,4 -dimethylhexanoate, 4,4゛-methylene-bis2.3.6-1-limethylphenol polyoxyethylene polyoxypropylenide dilaurate, 4
, 4"-methylene-bis2,3.6-) Limethylphenol polyoxybutylenide Stearic acid 2,4-dimethylhexanoate, 4°4"=(2", 2"-
(propylidene)-bis2,3.6-trimethylphenol polyoxyethylenide cicapric acid ester, 4.
4'-(2'', 2''-propylidene)-bis2,3.6
- Trimethylphenol polyoxypropylene compound 2
-Ethylhexanoic acid laurate, 4,4"-(
2″,2″-propylidene)-bis2.3.6-trimethylphenolpolyoxyethylenepolyoxypropylenide di2-decyltetradecanoic acid ester, 4゜4
"-(2', 2"-propylidene)-bis23.6-
Dolimethylphenol polyoxybutylenide dinonanoic acid ester, 4,4'-butylene-bis236-dolimethylphenol polyoxyethylenide di-2-methylhexanoate, 4,4'-butylene-bis2,3.
6-1-limethylphenol polyoxypropylenide capric acid lauric acid ester, 4,4°-butylene-
bis-2,3.6-dolimethylphenol polyoxyethylene polyoxypropylenide caprinic acid ester,
4゜4゜-Butylene-bis2,3.6-1-limethylphenol polyoxybutylenide di2-butyloctanoic acid ester, 4.4'-(2'',2''-butylene)-bis2,3 .6-1-limethylphenol polyoxyethylenide di2-ethylhexanoate, 4,4°-
(2'',2''-butylene)-bis2.3.61-limethylphenol polyoxypropylenide dibenzoic acid ester, 4.4'-(2''2''-butylene)-bis2
, 3. 6-1-limethylphenol polyoxyethylene polyoxypropylenide caproic acid ester, 4.
4″-(2′, 2″-butylene)-bis2,3.6-
1-limethylphenol polyoxobutylenide myristic acid 2-methylhexanoate, 4.4= (3
″, 3m-hexylene)-bis2,3.6-1-limethylphenol polyoxyethylenide capric acid caprylic acid ester, 4.4′-(3″, 3″-hexylene)
-bis2.3.6-1-limethylphenol polyoxypropylenide di-2-hebutyl undecanoic acid ester,
4.4”-(3”, 3”-hexylene)-bis2,3
゜6-Dolimethylphenol polyoxyethylene polyoxypropylenide dihebutanoic acid ester, 4,4°-
(3'',3''-hexylene)-bis2,3゜6-dolimethylphenol polyoxybutylenide benzoic acid caproic acid ester, 4.4''(51゜5''-hebutylene)
-Bis2,3.6-) Limethylphenol polyoxyethylenide caproic acid caprylic acid ester, 4.4'
-(5'',5''-heptylene)-bis2,3.6-trimethylphenolpolyoxypropylenide di2-octyldodecanoic acid ester, 4.4'-(5'',5#-heptylene)bis2, 3.6-) Limethylphenol polyoxyethylene polyoxypropylenide diundecanoic acid ester, 4.4'-(5″15″-hebutylene)
Bis2,3.6-) Limethylphenol polyoxybutylenide di2-ethylhexanoic acid ester, 4.4-
Methylene-bis2,6-diituprobylphenol polyoxyethylenide cycaprylic acid ester, 4,4゛-
Methylene-bis-2,6-diitupropylphenol polyoxypropylenide di-2-hebutyl undecanoate, 4゜4-methylene-bis-2,6-diitupropylphenol polyoxyethylene polyoxypropylenide di-2-ethyl Hexanoic acid ester, 44゛methylene-
Bis2,6-diitupropylphenol polyoxybutylenide caproic acid caprylic acid ester, 4.4'-(
2″,2″-propylidene)bis2,6-diisopropylphenolboxoxyethylenidedi2-butyloctanoic acid ester, 4.4′-(2″,2″-propylidene)-bis2,6-diisobrobyl Phenol polyoxybrobylenide myristic acid 2,4-dimethylhexanoate, 4.4'-(2", 2"-propylidene)-bis2,6-diitupropylphenol polyoxyethylene polyoxypropylenide di2 -Octyldodecanoic acid ester, 4,4°-(2”.

2"-propylidene)-bis2,6-diitupropylphenol polyoxybutylene sulfide capriic acid ester, 4.4"-butylene-bis2,6-diitupropylphenol polyoxyethylenide benzoic acid caprylic acid Ester, 4,4'-butylene-bis26-diitupropylphenol polyoxypropylenide di2-decyltetradecanoic acid ester, 4,4'-butylene-bis2.
6-Diitubropylphenol polyoxyethylene polyoxypropylenide dilauric acid ester, 4.4”
-Butylene-bis2.6-diitupropylphenol polyoxybutylenide caprylic acid 2-ethylhexanoate, 4.4"(2",2"butylene)-bis2.
6-Diitubrobylphenol polyoxyethylenide stearic acid 2heptyl undecanoate, 4.4
'-(2".

2m-butylene)-bis2,6-diituprobylphenol polyoxypropylenide di2,4-dimethylhexanoate, 4.4'-(2", 2"-butylene)-bis2,6-di Ituprobil phenol polyoxyethylene polyoxypropylenide to butanoic acid 2,4-
Dimethylhexanoate, 4.4'-(2"2"
-butylene)-bis2.6 diisopropylphenol polyoxybutylenide stearic acid 2-ethylhexanoate, 4.4"-(3", 3"-hexylene)
-Bis26-diitupropylphenol polyoxyethylenide dihebutanoic acid ester, 4.4'-(3"3"
-hexylene)-bis2,6-diitupropylphenol polyoxypropylenide di2-ethylhexanoate, 4.4'-(3", 3"-hexylene)-bis2,6-diitupropylphenol Polyoxyethylene polyoxypropylenide caprylic acid capric acid ester, 4.4'-(3''.

3"-hexylene)-bis2,6-diitupropylphenol polyoxybutylenide di2,4-dimethylhexanoate, 4.4"-(5", 5" butylene)
-bis2,6-diituprobylphenol polyoxyethylenide dibenzoic acid ester, 4,4"-(5", 5
"-hebutylene)-bis26-diitupropylphenol polyoxybrobylenide dinonanoic acid ester, 4.
4"(5"5'-heptylene)-bis2,6-diitubrobylphenol polyoxyethylene polyoxyprobylenide palmitic acid 2-ethylhexanoate, 4.4'-(5", 5"- hebutylene)-bis2.6
- dipropylphenol polyoxybutyrenated product di-2-octyldodecanoate, etc.

In addition to the above-mentioned aromatic esters, the lubricating oil of the present invention contains mineral oil, polyα-olefin,
polybutene, alkylbenzene, alkylnaphthalene,
Synthetic oils such as polyalkylene glycols, polyol esters, fatty acid diesters, phosphoric acid esters, polyphenyl ethers, etc., or mixed oils thereof may be blended.

However, the synthetic oils used are not limited to those mentioned above. The weight ratio of the aromatic ester to other lubricating oil components in the lubricating oil of the present invention is preferably used in the range of aromatic ester/other lubricating oil components -100/0 to 1/99.

Furthermore, various commonly used additives such as antioxidants, extreme pressure agents, rust inhibitors, antifoaming agents, and demulsifiers can be added to the lubricating oil of the present invention, if necessary.

Examples of antioxidants include phenolic antioxidants (for example, 2,6-di, monobutyl-4-methylphenol, 4,
4-methylenebis (2,6-di-butyl-phenol), etc.), amine antioxidants (e.g. p+ p+-
Dioctylphenylamine, monooctyldiphenylamine, phenothiazine, 3,7-cyoctylphenothiazine, phenyl-1-naphthylamine, phenyl-2-
naphthylamine, alkylphenyl-1-naphthylamine, alkylphenyl-2-naphthylamine, etc.), sulfur-based antioxidants (e.g., alkyl disulfide, thiodipropionate, benzothiazole, etc.), and zinc dialkyldithiophosphate, zinc diallyldithiophosphate. etc. are available.

As the extreme pressure agent, zinc dialkyldithiophosphate, zinc diallyldithiophosphate, dialkyl polysulfide, triallyl phosphate, trialkyl phosphate, etc. can be used. As the rust preventive agent, alkenylsuccinic acid, alkenylsuccinic acid derivatives, sorbitan monooleate, pentaerythritol monooleate, glycerin monooleate, amine phosphate, etc. can be used.

As the antifoaming agent, silicone oil (for example, dimethylpolysiloxane, etc.), organosilicates (for example, diethyl silicate, etc.), etc. can be used. Moreover, those that can be used as demulsifiers include polyoxyalkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene alkylamide, polyoxyalkylene fatty acid ester, and the like. However, it is not limited to the above.

The amount of these additives is usually 0.01 to 1 of the total amount of lubricating oil.
It is used in a range of 5% by weight. Further, the synthetic lubricating oil according to the present invention can be blended with an emulsifier or a dispersant, emulsified and dispersed in water, and used as a water-based lubricant.

The lubricating oil of the present invention is a hydraulic oil, metal working oil, compression oil, grease base oil, heat transfer oil,
It can be used as engine oil, turbine oil, turbocharger oil, etc., and is particularly effective in fields where high-temperature stability and lubricity are required.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 The viscosity of the lubricating oil base oils Nα1 to 5 of the present invention and conventional lubricating oils Nos. 6 to 12 shown in Table 1 was measured, and the thermal oxidative stability was also investigated by the following method.

The results are shown in Table 1.

<Method for measuring thermal oxidation stability> (+) 300°C thermal decomposition rate When heated at a temperature increase rate of 5°C/min in an air atmosphere using a Rigaku Heat Control Analyzer (TG), 300'
It is shown in percentage (%) that the sample achieved a&ffi in C.

(2) Rotary cylinder type oxidation stability test Performed according to JIS K-2514, 3, 3, from the start of the test IA to the end point, with the end point being the point where the pressure has decreased by 1.75 kgf/cm2 from the maximum pressure. time (min
, ) was calculated.

Table 1 shows that the base oils Nα1 to 5 for metal lubrication of the present invention have a higher thermal decomposition rate at 300°C according to TG and stable oxidation to rotary bombs according to JIS K-2514 than the conventional lubricating oils Nα6 to 12. It can be seen from the temperature test results that it is an excellent heat resistant base oil.

Claims (1)

[Claims] General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 and R_2 are hydrogen or alkyl groups having 1 to 10 carbon atoms, and R_3 and R_4 are 2 carbon atoms. ~30 acyl group, X and Y are alkyl groups having 1 to 5 carbon atoms, n and p are 0 to
represents an integer of 4, and when n and/or p are 2 or more, X
Y may be the same or different. In addition, A and B are alkylene groups having 2 to 4 carbon atoms, l, m
represents an integer from 0 to 30. ) A heat-resistant synthetic lubricating oil characterized by containing an aromatic ester represented by: