JP2549143B2 - New lubricant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a novel lubricant for a special high performance engine or general industrial machine.

[Conventional technology]

In recent years, ester lubricants have found a wide range of application fields as expensive lubricants.

For example, as a lubricating oil for tarbon engine oil (engine oil for aircraft jet engines, engines for high-performance turbo cars, gear oil, hydraulic oil, turbine oil) or general industrial machinery, it is possible to obtain high-grade oil that cannot be obtained with mineral oil. In the fields where physical and chemical properties are required, ester-based lubricating oil is expanding its demand. For these purposes, the properties required of the ester-based lubricating oil are excellent viscosity-temperature behavior, low melting point, high thermo-oxidative stability, low friction coefficient, and high pressure load capacity. Further, it is also an important required performance to sufficiently dissolve additives such as an antioxidant and a detergent-dispersant, and particularly when it is used as a lubricating oil for engine oil, a high dissolving power is required. As it is generally used as an ester-based lubricating oil to meet such required performance, dibasic acids (adipic acid, sebacic acid, etc.) diester and trimethylol obtained from alcohols branches (C ₇ -C ₁₃₎ There is a polyol ester obtained from propane (trivalent) or pentaerythritol (tetravalent) and a C _{3 to} C ₂₀ fatty acid.

[Problems to be Solved by the Invention]

However, these esters satisfy some but not all of the above performance requirements. For example,
The diester obtained from a dibasic acid and a branched alcohol is
Thermo-oxidative stability is insufficient, and tri- or tetra-esters obtained from trimethylolpropane or pentaerythritol and fatty acids have the drawbacks of high melting points and insufficient solubility of lubricating oil additives.

[Means for solving the problem]

Therefore, the inventors of the present invention have conducted extensive studies for the purpose of developing an ester-based oil agent having excellent lubricating properties, and as a result, have identified a specific ester formed from a fatty acid (or ester) and an alcohol (particularly a polyol) as a polymerization reaction or an olefin. Excellent viscosity-temperature behavior, lowering of melting point, improvement of thermal oxidation stability, lubricating oil additive by having a reaction product obtained by an addition reaction as an active ingredient, as compared with an ester which is not polymerized or treated with olefin. It has been found that the dissolving power of can be improved.

That is, the present invention is a kinematic viscosity at 40 ℃ (JIS; JIS 2283
-1956, JIS Z 8803-1959) is 5-500 cst and has two or more ester bonds, saturated aliphatic dibasic acid diester, phthalic acid diester, dihydric alcohol diester, trihydric alcohol triester, tetravalent An ester compound selected from alcohol tetraesters and tribasic acid triesters is polymerized so that the kinematic viscosity at 40 ° C is 1.2 times or more and 50 times or less and 10 to 5000 cst of the original ester compound, or an olefin. The present invention provides a novel lubricating oil agent which is characterized in that a reaction product obtained by addition reaction with is used as an active ingredient.

The ester to be modified in the present invention is 1
Those having at least two or more ester groups in the molecule, for example, saturated aliphatic dibasic acid diesters such as diisodecyl adipate and dioleyl adipate, diethyl phthalate such as dioctyl phthalate and neopentyl glycol dicaprylate, neopentyl glycol Diolates, dihydric alcohol diesters such as ethylene glycol diolate, trimethylolpropane tricaprate, glycerin trioleate, pentaerythritol tetraoleate, coconut oil, beef tallow, tetrahydric alcohol tetraesters such as castor oil or tetrahydric alcohol tetraesters,
Tribasic acid triesters such as triisostearyl trimellitate can be used, but are not limited thereto. Among them, those having 20 or more carbon atoms are preferable.

Further, when polymerizing the ester compound, or in the addition reaction of the olefin, as a radical generator, for example, an organic peroxide, an inorganic peroxide, an azo compound,
Light or radiation can be used. Among them, it is desirable to use an organic peroxide as an initiator, and good organic peroxides include dialkyl peroxide, hydroperoxide, diacyl peroxide, peroxy ester, ketone peroxide, dioxydicarbonate, and peroxy. Examples include ketals and azoisobutyronitrile. Specific examples thereof include ditertiary butyl peroxide, dicumyl peroxide, tertiary butyl hydroperoxide, etc., but are not particularly limited thereto.

The type of olefin is not particularly limited, but preferably
Α-Olefins of about C ₃₀ or less, especially C _{4 to} C ₃₀ , are preferable, and those of C _{8 to} C ₂₀ are more preferable. Also, α, ω
-The use of dienes or trienes etc. promotes crosslinking of the esters.

As a reaction condition for polymerizing the ester compound, generally, a method of adding a radical generator as an initiator to the ester compound heated to 50 to 250 ° C. without a solvent or by diluting with a solvent is added. Alternatively, a method of gradually increasing the temperature by mixing an ester compound and an initiator is adopted.
The amount of the radical generator used during the polymerization is preferably 0.01 to 5 times the equivalent amount of the ester group, and particularly preferably 0.10 to 0.50 times the equivalent amount.

In addition, the reaction conditions for adding olefins include:
Generally, a method of adding an olefin and a radical generator to an ester compound heated to 50 to 250 ° C, or a method of adding a radical generator to a mixture of an ester compound and an olefin, or an ester compound and a radical generator. A method of adding an olefin to a mixture of agents may be used. The amount of the olefin used is preferably not more than 2 times the equivalent of the ester group, but not more than 1 times the equivalent. As the amount of the radical generator used in the olefin addition,
The amount of olefin used is preferably 0.01 to 5 mol times, and particularly preferably 0.05 to 2.00 mol times.

The reaction product thus obtained has a kinematic viscosity at 40 ° C of 1.2 to 50 times that of the original ester compound and 1
It is 0 to 5000 cst, preferably 20 to 2000 cst. 10c
If it is less than st or exceeds 5000 cst, the viscosity of the lubricating oil is too low or too high, which is not preferable.

Further, various additives to the base oil of the present invention as necessary, for example, antioxidants (phenolic antioxidants, zinc dialkyldithiophosphates, zinc diallyldithiophosphates, amine antioxidants, etc.), extreme pressure additives (Dialkyl polysulfide, diallyl polysulfide, zinc dialkyldithiophosphate, etc.), viscosity index improver (methacrylate type additive, etc.), detergent dispersant (alkaline earth metal sulfonate, alkyl hydroxybenzylamine, etc.) may be used in combination. it can.

Lubricants containing esters modified according to the present invention have low melting points despite good viscosity-temperature behaviour, and relatively high viscosities, making them conventionally used as low-melting and high-viscosity ester oils. It can also be advantageously used in the industry where the developed complex ester or branched ester has been retained. Surprisingly, it has been found that the desired viscosity can be obtained depending on the amount of the initiator used, and one of the characteristics of the present invention is that the viscosity can be adjusted depending on the application.

〔Example〕

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples described below.

Synthesis Example 1 357.6 g (0.6 mol) of trimethylolpropane tricaplate was placed in a 1-liter four-necked flask equipped with a stirring rod, a nitrogen gas blowing tube, a thermometer, a dropping device, and a separator with a cooling tube, and a nitrogen atmosphere was obtained. It is heated to 190 ° C under the following conditions and the reaction initiator, ditertiary butyl peroxide (DT
26.3 g (0.18 mol), which is abbreviated as BPO), was added dropwise over 2 hours, and the reaction was carried out while removing the low boiling point compound by-produced outside the system. After the reaction, aged for 30 minutes, then 190 ℃ / 10〜30mm
The low boiling point compound was completely distilled off with Hg, and the reaction product A355.6
g got. The number average molecular weight (vapor pressure equilibrium method) and kinematic viscosity (JIS K-2283-1956, JIS Z 8803-195) of this reaction product.
9) and melting point (JIS K-2269) are shown in Table 1.

Synthesis Example 2 357.6 g (0.6 mol) of trimethylolpropane tricaplate was placed in a 1-liter four-necked flask equipped with a stirring rod, a nitrogen gas blowing tube, a thermometer, a dropping device, and a separator with a cooling tube, and a nitrogen atmosphere was obtained. Under heating to 190 ℃, 26.28 g (0.18 mol) of DTBPO as a reaction initiator and 1-dodecene 100.
A mixed solution of 8 g (0.6 mol) was added dropwise over 2 hours, and the reaction was carried out while removing the low boiling point compound by-produced from the system. After the reaction, it was aged for 30 minutes and then the unreacted olefin was completely distilled off at 190 ° C / 10 to 30 mmHg, and the reaction product D435.7g
I got The number average molecular weight (vapor pressure equilibrium method) and kinematic viscosity (JIS K-2283-1956, JIS Z 8803-195) of this reaction product.
9) and melting point (JIS K-2269) are shown in Table 1.

Similarly, the reaction was carried out under each reaction condition and Table 1
Reaction products A to L were obtained.

Example 1 A to L, M to O as their raw materials, mineral oil, and poly α-olefin were measured for evaporation loss, dynamic friction coefficient, pressure resistance load, and additive solubility by the methods described below. The results are shown in Table 1.

Evaporation weight loss: The evaporation weight loss at 300 ° C was obtained using a thermobalance (manufactured by Rigaku Denki).

Temperature rising rate 5 ° C / min. Dynamic friction coefficient in air atmosphere: The dynamic friction coefficient was measured by the Soda pendulum test.

Sample oil temperature 60 ℃ Pressure resistance load: The pressure resistance capacity was determined by the Soda four-ball friction test.

Rotation speed 250 rpm Additive solubility: Add 5 wt% of polybutenyl succinimide, a lubricating oil additive commonly used for engine lubricating oil, to the sample oil, and after heating, leave it overnight at room temperature to generate turbidity Was visually observed. The one in which turbidity occurred was marked as × Note) TMP; trimethylolpropane NPG; neopentyl glycol The numerical values of the reaction conditions indicate the number of moles.

As is clear from Table 1, the lubricating oil agent of the present invention has an improved viscosity index, a lowered melting point, an improved thermal oxidative stability, and an improved solubility of the lubricating oil additive as compared with the ester ratio before treatment. It has been achieved, and has preferable performance as a lubricating oil. Although the mineral oils and poly α-olefins shown in Comparative Examples are generally known as lubricating oils, the lubricating oil of the present invention has a high viscosity index, a low melting point, good thermal stability, It has a low coefficient of dynamic friction and high pressure-resistant load capacity,
It is clearly a good lubricant.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C10N 20:02 30:02 40:25 70:00 (56) References JP-A-58-65246 ( JP, A)

Claims (3)

(57) [Claims] 1. A kinematic viscosity at 40 ° C. (JIS; JIS2283-1956,
JIS Z 8803-1959) is 5 to 500 cst and has two or more ester bonds, saturated aliphatic dibasic acid diester, phthalic acid diester, dihydric alcohol diester,
An ester compound selected from trihydric alcohol triesters, tetrahydric alcohol tetraesters, and tribasic acid triesters is used as an ester compound whose kinematic viscosity at 40 ° C is the original.
A novel lubricating oil comprising a reaction product obtained by polymerization reaction or addition reaction with an olefin so as to be 1.2 times or more and 50 times or less and 10 to 5000 cst, as an active ingredient. 2. The novel lubricating oil agent according to claim 1, wherein the olefin has 4 to 30 carbon atoms. 3. The novel lubricant according to claim 1, wherein the ester compound has 20 or more carbon atoms.