JPS5859293A - Liquid antioxidant for lubricating oil - Google Patents

Abstract

PURPOSE:To obtain a liquid antioxidant for lubricating oil having excellent antioxidizing performance and good workability, by mixing a methylene bisphenol, dinonyldiphenylamine and tridecyl thiodipropionate. CONSTITUTION:A methylene visphenol(I) of formulaI(wherein R1 and R2 are each 1-4 alkyl), dinonyldiphenylamine (II) of formula II and tridecyl thiodipropionate (III) of formula III are mixed in a wt. ratio of(I):(II):(III) of 1:1-20:1-20 and (I):(II)+(III) of 1:3. In said compd. of formulaI, in view of antioxidizing performance, R1 and R2 are each particularly pref. 1-2C alkyl, which is exemplified by 2,2'-methylenebis (6-tert-butyl-4-methylphenol, 2,2'-methylenebis (4,6-di- tert-butylphenol), etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antioxidant that prevents deterioration of lubricating oil due to oxidation.

Generally, when lubricating oils (mineral oil lubricating oils and synthetic lubricating oils are collectively referred to) are used, various additives are added to improve their properties9.

Special Number ζVarious lubricating oils that are exposed to high temperatures in the presence of air, such as hydraulic oil, turbine oil,
Antioxidants are added to these oils to improve their oxidative stability, such as gear oils, etc.), gold-processing oils (rolling oils, cutting oils, etc.).

Conventionally, in order to improve the oxidation stability.

For example, dioctyldifunylamine, phenothiazine,
Aromatic amines such as N,N'-di-tert-butyl-paraphenylene diamici, 2.6-di-tert-butyl-para-cresol%4.4'-bis-(2,6-dibutyl) virphenol).

4.4'-methyledibis-(2#6-di-tert-butylphenol) 4 hiscidadophenol, antimony cyamyl dithiocarbamate.

Although various antioxidants such as metal salts such as zinc cyamyl dithiophosphate have been provided and used, none of these antioxidants can be said to have satisfactory performance, and Most of the antioxidants with relatively good performance are solid, and Ill? When added to oil and dissolved, it was not only difficult to dissolve in the bath, but also had the disadvantage of scattering, which caused problems in workability.

Against this background, liquid 71! has excellent anti-oxidation performance and good workability. There was a strong desire to develop antioxidants for lubricating oils.

In view of this, the present inventors have conducted intensive studies to develop a liquid high-performance antioxidant for lubricating oils. As a result, by mixing the compounds specified in the present invention in a specific ratio, each compound can be used alone. A surprising synergistic effect that could not have been predicted can be obtained, and it has extremely superior antioxidant performance compared to conventionally known antioxidants. The present inventors have discovered that the present invention is also excellent.

That is, the present invention provides methylene bisphenol d (I) represented by the general formula (Il (wherein R1 and Rm may be the same or different and represent an alkyl group having 1 to 4 carbon atoms), the formula dinonylated diphenylamine value shown by (9)) and tridecylthiodipropionate (2) CHg (EHg (X)QCR13grB
(2) CHwOH Fumoto CO
OC1C00C1 (I):(II):IO=1:1~20:
1~2 G (Jewel ratio) Te; 6) Tsu, (I):
The present invention provides a liquid antioxidant for lubricating oil which is mixed in a ratio of (IF)+1Ll=1:8 or more (m gravity ratio).

In the compound of general formula (I) used in the present invention, % substituent R
The meanings of 1 and kan are as described above, but from the viewpoint of antioxidant performance, R1 and R are particularly preferably alkyl groups having 1 to 1 carbon atoms. Specific examples of such compounds of general formula (1) include 2゜2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4- ethylphenol), 2
゜2'-methylenebis(6-tertiary phthyl-4-propylphenol), 2,2'-methylenebis(4,6-di-tertiary butylphenol), 2゜2'-methylenebis(
6-tertiary butyl-4-secondary butylphenol), 2
, 2'-methylenebis (6-@tert-butyl-4-n-butylphenol), etc., but derivatives of these may also be used.

In addition, in the dinonylated diphenylamine of Formula 1,
The substitution position of each nonyl group is not limited in any way and may be the same or different.

The liquid antioxidant of the present invention is a compound of general formula (1) and α
) compound and (2) compound were mixed, and the mixture was heated to 60 to 150°C.
More preferably, it can be easily produced by dissolving it while stirring at 10G to 180T.

The mixing ratio of each component is 1 part of the compound of general formula (1) to 1 to 20 parts of the compound of formula (I) to 1 part of the compound of formula (2). In terms of performance, the compound of formula (2) and the compound of formula (2) are preferably used in an amount of 1 to 10 parts by weight. In addition, from the viewpoint of anti-forging performance and stability as a liquid, the sum of the compound of formula (II) and the compound of formula (2) is more than axii times E than the compound of general formula (1), but 4 to A ratio of 12 iris is particularly preferable in terms of performance.

The lubricating oil that can be used in the present invention is not particularly limited.

For example, they can be synthetic oils or mineral oils based on esters of mono- and/or dicarboxylic acids, but those based on mineral oils are suitable for f8.

The additive type of the liquid antioxidant of the present invention can be lachrylated over a wide range depending on the type of lubricating oil, conditions of use, etc., but it is generally in the range of 0.1 to 1O weight it'X relative to the lubricating oil.

The liquid antioxidant of the present invention may be used in combination with conventionally known antioxidants such as other amine antioxidants, phenolic antioxidants, and zinc dialkyl ditheophosphates, and may improve the performance characteristics of certain noodles. Anti-wear agent, anti-corrosion agent for teaching purposes.

It can also be used in combination with additives such as viscosity index improvers, pour point depressants, Weiki dispersants, and extreme pressure agents.

Next, the present invention will be specifically explained with reference to Examples.

Example I According to the rotary zemp oil oxidation test method according to A8TM-D-2272, the antioxidant of camphorax shown in fi-1 was
．． The test lubricating oil &Of added at two levels of 2% and 0.6% (both m]t) was mixed with distilled water and a copper spiral (
After polishing, washing with ethyl ether and drying), the mixture was placed in a glass container and oxidized in an acidic atmosphere.

The glass container was placed in a stainless steel container connected to a pressure recorder, and the container was placed in an oil bath at 150°C.

It was rotated axially at 100 revolutions/min at an angle of 80 degrees to the horizontal.

The initial oxygen pressure before heating is adjusted to TKIlctd, and as heating progresses, the pressure increases, and remains constant until oxidation begins. The time when the pressure decreased by 2.0 Kf/- was recorded as the acid absorption induction period in minutes.

The results are shown in Table-2. The lubricating oil used was neutral oil #160.

Moreover, the symbols of the compounds shown in Table 1-1 are as follows.

Compound number Compound @ name 2.2'-methylenebis(6-tertiary phthyl-4-methylphenol) B 2.2'-methylenebis(6-tertiary phthyl-4-ethylphenol) (32,!'- Methylenebis(4,6-di-tertiary-butylphenol) D 4.4'-methylenebis(2,6-di-tertiary-butylphenol) E Dinonyl-diphenylamine F
Dioctyl-diphenylamine G Ditridecyl-thiodipropionate Table-1

Claims (1)

[Scope of Claims] Methy, lene bisphenol d(1) represented by the general formula (in the formula, Rr and loss may be the same or different and represent an alkyl group having 1 to 4 carbon atoms), dinonylated diphenylamine represented by I[) and tridecylthiodipropionate (2) represented by formula (2) OHt -G5Hz (3UOC+aHrr8
@) Oklto (Igcol)
c1aHm wo(I):(II):(ll=1: 1~20.:
1 to 20 (weighted) and (1): (II)
+(2) A liquid antioxidant for lubricating oil mixed in a ratio of 2128 or more (by weight).