JPH07118677A - New synthetic lube oil - Google Patents

Abstract

PURPOSE:To obtain a synthetic lube oil containing a specific polycondensation product, excellent in stability to hydrolysis and heat resistance and useful for a metal processing oil, etc. CONSTITUTION:This synthetic lube oil contains a polycondensation product of one or two or more kinds of aminopolyols among di-, tri- and tetrahydric aminopolyols expressed by formula I to formula V [R1 is a 1-20C alkyl, alkenyl, cyclohexyl or phenyl; R2 is a 1-6C alkyl, cyclohexyl or phenyl; X is H or methyl; (n) is 1-3] and having tertiary nitrogen, a dialkyl carbonate and a monohydric alcohol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbonate compound which exhibits extremely excellent hydrolysis stability against acids and alkalis, such as rolling oil, cutting oil, grinding oil, drawing oil, press oil and the like. It can be used as a metal working oil, a metal plastic working oil, and a lubricating oil having good friction resistance and wear resistance when sliding.

[0002]

2. Description of the Related Art Lubricating oils are widely used in various industrial fields, and their applications are mainly used for the purpose of reducing friction and wear on the contact surfaces during metal working and contact sliding between metals. Further, the physical properties required for the lubricating oil differ depending on the field of use, but generally they are lubricity, oxidation stability, thermal stability, low temperature fluidity, viscosity characteristics and the like.

In order to satisfy such performances, mineral oils, animal and vegetable fats and oils and fatty acids derived from animal and vegetable fats have been conventionally used as base oils and additives for various lubricating oil compositions, and α-olefin oligomers have been used in synthetic products. , Polyalkylene glycol, fatty acid monoesters and diesters, polyol esters, phosphoric acid esters, silicate esters, silanes, silicones, polyphenyl ethers, fluorocarbons, etc. are used. It is used as a lubricating oil composition.

Specifically, in the case of cold rolling oil used for thin steel sheets, animal and vegetable oils (beef tallow, lard, soybean oil, rapeseed oil, palm oil, coconut oil, etc.) as base oils and mineral oils as base oils. Are roughly divided into Generally, a rolling oil based on a mineral oil is used in order to improve rolling lubricity, animal and vegetable fats and oils and fatty acids (capric acid, lauric acid, myristic acid, stearic acid, oleic acid, linolenic acid, etc.) or esters (trimethylolpropane, It is used by adding an oiliness improver such as pentaerythritol, alcohol such as 2-ethylhexyl alcohol, and monoester, diester of carboxylic acid and synthetic ester such as polyester).

On the other hand, lubricating oils used for cutting and grinding metal are mineral oil, animal and vegetable oils, extreme pressure additives, surfactants, defoamers, metal anticorrosives, antioxidants, preservatives and antifungal agents. And the like are appropriately mixed according to the purpose. The cutting fluid is usually diluted with water by 10 to 100 times, but depending on the case, a non-water cutting fluid may be used. The basic conditions that cutting and grinding oil must have are lubricity, cooling properties, rust prevention properties, and other auxiliary conditions such as foaming properties.
It has no rough hands, human toxicity, and odor. The cutting and grinding fluid must have a good balance of the above-mentioned performances even if the emphasis is placed on it depending on the purpose of use and conditions, but a cutting and grinding fluid that can sufficiently satisfy these requirements has not yet been put into practical use. Is the current situation.

[0006]

In other words, with the recent diversification and sophistication of industrial fields, the operating conditions of lubricating oils have become severer, and the performance required by conventional synthetic lubricating oils has been satisfactorily achieved. It's getting harder to meet. Specifically, strong acidity (pH 2-3) and strong alkaline (pH 11)
When using a lubricating oil in an emulsion under the environment of ~ 12) range, higher hydrolysis resistance performance is required. Further, when used at high temperature, there is a need for a lubricating oil having good thermal stability. Therefore, an object of the present invention is to provide a synthetic lubricating oil which has good lubricating properties, and is excellent in hydrolysis resistance in a strongly acidic and strongly alkaline region and in thermal stability.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a lubricating oil containing a specific polycarbonate compound is suitable for this, and completed the present invention. Came to. That is, the present invention is
It is a synthetic lubricating oil containing a polycondensation product of a dihydric carbonate and a dihydric carbonate having a tertiary nitrogen, a dialkyl carbonate and a monohydric alcohol. The polycondensate of the present invention is, so to speak, one type of polycarbonate compound, and may be the one obtained by reacting the above-mentioned aminopolyol, dialkyl carbonate and monohydric alcohol at the same time, but it is preferably a reaction product of aminopolyol and dialkyl carbonate. What reacted with a monohydric alcohol is preferable.

The 2- to 4-valent aminopolyol having a tertiary nitrogen used for synthesizing the polycondensate of the present invention is mainly represented by the following general formula (A), (B), (C), (D) or ( It is preferable that one kind or two or more kinds shown in E) are included, but the present invention is not limited thereto.

[0009]

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10]

However, in the above formulas (A) to (E), R _{1 is} an alkyl group having 1 to 20 carbon atoms, an alkenyl group, a cyclohexyl group or a phenyl group. R ₂ : an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group,
Or a phenyl group. X: H or a methyl group. n: an integer of 1 to 3.

That is, all of the above aminopolyols commonly have an-(CH ₂ CXHO) n-H group (where X = H or a methyl group and an integer of n = 1 to 3) as an alcohol moiety. Among them, the divalent amino alcohol represented by the general formula (A) is a monoamine type diol having an alkyl group, an alkenyl group, a cyclohexyl group or a phenyl group having 1 to 20 carbon atoms as R ₁ , such as methyldiethanolamine and methyl. Diisopropanolamine,
Ethyldiethanolamine, propyldiethanolamine, propyldiisopropanolamine, butyldiethanolamine, butyldiisopropanolamine, cyclohexyldiethanolamine, cyclohexyldiisopropanolamine are preferably used. Moreover, ethylene oxide 2 mol addition dodecyl amine, propylene oxide 3 mol addition octadecyl amine, beef tallow alkyldiisopropanol amine, etc. can also be used.

The dihydric amino alcohol represented by the general formula (B) is a piperazine of diamine type diol, for example, N, N'-bis (2-hydroxyethyl) piperazine, N, N'-bis (2- Hydroxypropyl) piperazine, N, N′-bis (2-hydroxyethyl) -2-
Methylpiperazine and N, N'-bis (2-hydroxypropyl) -2-methylpiperazine are preferred. N, N '
-Bis (ethylene oxide 2 mol addition) piperazine,
N, N'-bis (propylene oxide 3 mol addition) piperazine etc. may be used. The trivalent amino alcohol represented by the general formula (C) is a monoamine type triol, and for example, triethanolamine and triisopropanolamine are preferable. Moreover, ethylene oxide 3 mol addition monoamine, propylene oxide 2 mol addition monoamine, etc. can also be used.

The trihydric amino alcohol represented by the general formula (D) is an isocyanurate of triamine type triols, and for example, tris (2-hydroxyethyl) isocyanurate and tris (2-hydroxypropyl) isocyanurate are preferable. Further, tris (addition of 3 mol of propylene oxide) isocyanurate may be used. The tetravalent amino alcohol represented by the general formula (E) is a diamine type tetraol having an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group or a phenyl group as R ₂ , and is, for example, N, N ′, N, N. Preferred are'-tetrakis (2-hydroxypropyl) ethylenediamine and N, N ', N, N'-tetrakis (2-hydroxyethyl) phenylenediamine. In addition, N, N ', N, N'-tetrakis (2-
Hydroxyethyl) hexylenediamine, N, N ′,
N, N'-tetrakis (ethylene oxide 2 mol addition) ethylenediamine etc. can also be used.

In addition to the above various aminopolyols,
Aminopolyols such as polyoxyethylene octadecylamine and polyoxypropylene beef tallow alkylamine can also be used as the raw material of the present invention.

Next, the dialkyl carbonate preferably has a lower alkyl group having 1 to 6 carbon atoms, and specific examples thereof include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate and dihexyl carbonate. Also, dicyclohexyl carbonate can be used. In the present invention, a dialkyl carbonate having an alkyl group having more than 6 carbon atoms may be used, but in this case, the reaction is difficult to proceed and it tends to be difficult to remove it as an unreacted material.

The monohydric alcohol preferably has 5 to 50 carbon atoms and has a linear or side chain alkyl group, alkenyl group or aryl group, and specific examples thereof include amyl alcohol, hexanol, heptanol and octanol. , Nonanol, decanol, lauryl alcohol, tridecanol, myristyl alcohol, cetanol, stearyl alcohol, oleyl alcohol, eicosenol, Hisocol 246 (a side chain mixed alcohol having 24 to 26 carbon atoms, manufactured by Ito Oil Co., Ltd.), NJ call 3236. (C32-36 side chain mixed alcohol, manufactured by Shin Nippon Rika Co., Ltd.), Unilin alcohol 550
(C50 straight-chain mixed alcohol, manufactured by Petrolite Co., USA), benzyl alcohol and the like can be mentioned.

In synthesizing the polycondensate of the present invention, the compounding ratio of the above raw materials, that is, the reaction molar ratio may be appropriately selected, and the aminopolyol is represented by the general formula (A) or (B). At this time, preferably the aminopolyol / dialkyl carbonate / monohydric alcohol = 1/2
/ 2 to 2/3/2, and when the aminopolyol is represented by the general formula (C) or (D), the aminopolyol / dialkyl carbonate / monohydric alcohol = 1/3/3 to 5/11/7 and when the aminopolyol is represented by the general formula (E), the aminopolyol / dialkyl carbonate / monohydric alcohol = 1/4/4 to 5/18/14 is preferable.
Is. When the aminopolyol is used as a mixture of two or more kinds, it may be set with reference to such a blending ratio.

In the present invention, the polycondensation reaction preferably uses the following two-step reaction. That is, first, the first step reaction is performed with the aminopolyol and the dialkyl carbonate, and then the second step reaction is performed with the reaction product and the monohydric alcohol. In the first-step reaction, dialkyl carbonate may be added in a set molar equivalent amount to the amino polyol, but since it is azeotropically distilled with an alcohol by-produced from the dialkyl carbonate, 1.2 to 1.5 times the set molar equivalent amount of dialkyl carbonate is used. Is good. In the second-step reaction, a monohydric alcohol was added to the first-step reaction product in a set molar equivalent amount, the reaction was terminated when the theoretical amount of alcohol was distilled off, and unreacted dialkyl carbonate was removed under normal pressure or reduced pressure. By distilling off, the polycondensate of the present invention can be obtained.

The reaction temperature is 90 ° C. to 200 ° C., which is near the boiling point of the dialkyl carbonate.
Known transesterification catalysts can be used in such reaction, for example, lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium,
It may be appropriately selected from metals such as cobalt, germanium, tin, lead, antimony, arsenic, and cerium, and alkoxides thereof.

2-4 having tertiary nitrogen thus obtained
The polycondensation product of a valent aminopolyol, a dialkyl carbonate and a monohydric alcohol is a known mineral oil, animal or vegetable fats and oils, fatty acids, extreme pressure additives as it is, or if necessary, within the scope of the object of the present invention, A lubricating oil can be prepared by adding a surfactant, an antifoaming agent, a metal anticorrosive, an antioxidant, an antiseptic, a fungicide, and the like. The amount of the polycondensate compounded in the lubricating oil of the present invention varies depending on the application, purpose and usage of the lubricating oil, but is generally 0.1 to 50% by weight, preferably 1 to 30% by weight.

[0021]

EXAMPLES In the following synthesis examples and examples, parts are based on weight. Synthesis Example 1 A 1-liter four-necked flask equipped with a stirrer and a thermometer was charged with 219 parts (2 mol) of dibutylethanolamine, 184 parts (3 mol) of dimethyl carbonate, and 0.06 part of titanium tetraisopropoxide as a catalyst. , 90 ℃
And reacted for 4 hours. After cooling, further nonanol 196
(2 mol) was added and reacted at 150 ° C. for 3 hours until the theoretical amount of ethanol was distilled off, and unreacted nonanol was distilled off under reduced pressure to obtain a polycondensate of the present invention.

Synthesis Example 2 N, N-bis (2-hydroxyethyl) piperazine 17 was placed in a 1-liter four-necked flask equipped with a stirrer and a thermometer.
4 parts (1 mol), 228 parts of dipropyl carbonate (2
Mol), and sodium methylate as a catalyst 0.01
A portion was charged and the reaction was carried out at 120 ° C. for 4 hours. After cooling, 564 parts (2 mol) of oleyl alcohol was added, and 1 part was added.
The reaction was carried out at 50 ° C. for 5 hours until the theoretical amount of propanol was distilled off to obtain a polycondensate of the present invention.

Synthesis Example 3 A 1-liter four-necked flask equipped with a stirrer and a thermometer was charged with 137 parts (4 mol) of triethanolamine, 244 parts (9 mol) of diethyl carbonate, and 0.02 part of magnesium as a catalyst. The reaction was carried out at 0 ° C for 6 hours. After cooling, 213 parts (5 mol) of lauryl alcohol was further added and reacted until the theoretical amount of ethanol was distilled off, and the unreacted carbonate and lauryl alcohol were distilled off under reduced pressure to obtain the polycondensate of the present invention. .

Synthesis Example 4 Tris (2-hydroxyethyl) isocyanurate 290 was placed in a 1-liter four-necked flask equipped with a stirrer and a thermometer.
(3 mol), 167 parts (5 mol) of dimethyl carbonate, and 0.03 part of titanium tetraisopropoxide as a catalyst were charged and reacted at 90 ° C. for 5 hours. After cooling, 144 parts (3 mol) of 2-ethylhexanol was further added, and the mixture was reacted at 200 ° C. for 5 hours until the theoretical amount of methanol was distilled off, and the unreacted carbonate and 2-ethylhexanol were distilled off under reduced pressure. To obtain the polycondensate of the present invention.

Synthesis Example 5 In a 1 liter four-necked flask equipped with a stirrer and a thermometer, 117 parts (2 moles) of ethylenediaminetetraisopropanol, 160 parts (7 moles) of di-n-propyl carbonate, and sodium methylate as a catalyst of 0. 03 parts were charged and reacted at 120 ° C. for 4 hours. After cooling, 324 parts (6 mol) of isostearyl alcohol was further added and reacted until the theoretical amount of propanol was distilled off, and unreacted carbonate and isostearyl alcohol were distilled off under reduced pressure to obtain the polycondensation of the present invention. It was

Examples 1 to 5 and Comparative Examples 1 to 3 The polycondensates of the present invention obtained in Synthesis Examples 1 to 5 and three kinds of fatty acid esters as comparative examples were tested for acid and alkaline hydrolysis stability. did. The results are shown in Tables 1 and 2. From both test results, it was revealed that the polycondensate of the present invention has excellent stability against hydrolysis in acidic and alkaline conditions.

[Test Method for Acid Hydrolysis Stability] Approximately 2 samples
Correctly weigh g in a saponification value measuring flask, and add correctly 50 ml of 1 / 3N hydrochloric acid (pH = 0.5). Next, the flask was equipped with a condenser and heated at 90 ° C. After heating for a certain period of time and cooling, remove the condenser and add a few drops of thymol blue neutral red indicator,
Titrate with 3N potassium hydroxide standard solution. A blank test will be conducted in parallel with the main test. The saponification value was measured at regular intervals, and the acid hydrolysis rate (%) was calculated from the following formula. Acid hydrolysis rate (%) = V _a / SV × 100 where V _{a is} the saponification value of the sample after a certain period of time. SV: Saponification number of sample (heated with 1N ethanolic potassium hydroxide solution for 6 hours).

[0028]

[Table 1]

[Test Method for Stability of Alkaline Hydrolysis] About 2 g of a sample was accurately weighed in a saponification value measuring flask, and 1 / 3N ethanolic potassium hydroxide solution 2
Add 5 ml correctly. Next, a condenser is attached to the flask and heated at 85 ° C. for a certain period of time, then cooled, the condenser is removed, a few drops of phenolphthalene indicator are added, and titration is carried out with a 1 / 3N hydrochloric acid standard solution. A blank test will be conducted in parallel with the main test. The saponification value was measured at regular intervals, and the alkali hydrolysis rate (%) was calculated from the following formula. Alkaline hydrolysis rate (%) = V _b / SV × 100 where V _b : Saponification value of the sample after a certain period of time. SV: Saponification number of sample (heated with 1N ethanolic potassium hydroxide solution for 6 hours).

[0030]

[Table 2]

Further, general characteristics of the polycondensates of the present invention obtained in Synthesis Examples 1 to 5 and three kinds of fatty acid esters as comparative examples,
Also, the coefficient of dynamic friction and heat resistance as the suitability for lubricating oil were measured. The dynamic friction coefficient was measured at 25 ° C. using a Soda pendulum type oil friction tester, and the heat resistance was measured using a thermobalance. The results are shown in Table 3. It can be seen from Table 3 that the polycondensate of the present invention has an appropriate viscosity as a lubricating oil base, a dynamic friction coefficient equal to or less than that of a conventional lubricating oil base, and excellent heat resistance. Became clear.

[0032]

[Table 3]

[0033]

EFFECT OF THE INVENTION It is possible to provide a synthetic lubricating oil which is excellent in hydrolysis resistance in the strongly acidic and strongly alkaline regions and has good lubricity, which is used for metal working. The lubricating oil of the present invention has applications such as cold rolling oil for steel plates and metal cutting and grinding.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10N 30:08 40:02 40:20

Claims (12)

[Claims] 1. A synthetic lubricating oil comprising a polycondensation product of a dihydric carbonate and a monohydric alcohol with a dihydric to tetrahydric aminopolyol having tertiary nitrogen. 2. The aminopolyol has the following general formula (A):
The lubricating oil according to claim 1, which is one kind or two or more kinds represented by (B), (C), (D) or (E). [Chemical 1] [Chemical 2] [Chemical 3] [Chemical 4] [Chemical 5] However, in the above formulas (A) to (E), R _{1 is} an alkyl group having 1 to 20 carbon atoms, an alkenyl group, a cyclohexyl group, or a phenyl group. R _2: an alkyl group, a cyclohexyl group or a phenyl group having 1 to 6 carbon atoms. X: H or a methyl group. n: An integer of 1 to 3. 3. The aminopolyol represented by the general formula (A) is methyldiethanolamine, methyldiisopropanolamine, ethyldiethanolamine, propyldiethanolamine, propyldiisopropanolamine,
The lubricating oil according to claim 2, which is butyldiethanolamine, butyldiisopropanolamine, cyclohexyldiethanolamine, or cyclohexyldiisopropanolamine. Wherein the general formula (B) amino polyol NN represented by ^'- bis (2-hydroxyethyl) piperazine, ^NN' - bis (2-hydroxypropyl) piperazine, NN ^'- bis (2-hydroxyethyl) 2-methyl piperazine, or NN ^'- bis (2-hydroxypropyl) lubricating oil according to claim 2 which is 2-methylpiperazine. 5. The lubricating oil according to claim 2, wherein the aminopolyol represented by the general formula (C) is triethanolamine or triisopropanolamine. 6. The lubricating oil according to claim 2, wherein the aminopolyol represented by the general formula (D) is tris (2-hydroxyethyl) isocyanurate or tris (2-hydroxypropyl) isocyanurate. 7. The aminopolyol represented by the general formula (E) is N, N ′, N, N′-tetrakis (2-hydroxypropyl) ethylenediamine or N, N ′, N, N′-.
The lubricating oil according to claim 2, which is tetrakis (2-hydroxyethyl) phenylenediamine. 8. The dialkyl carbonate has 1 to 6 carbon atoms.
The lubricating oil according to claim 1, which is an alkyl group of 9. The lubricating oil according to claim 1, wherein the monohydric alcohol has 5 to 50 carbon atoms and has a linear or side chain alkyl group, alkenyl group or aryl group. 10. The reaction molar ratio of the aminopolyol represented by the general formula (A) or (B), the dialkyl carbonate and the monohydric alcohol is such that aminopolyol / dialkylcarbonate / monohydric alcohol = 1/2/2 to 2 / 3 /
The lubricating oil according to any one of claims 1, 2, 3, 4, 8 or 9, which is 2. 11. The reaction molar ratio of the aminopolyol represented by the general formula (C) or (D), the dialkyl carbonate and the monohydric alcohol is such that aminopolyol / dialkylcarbonate / monohydric alcohol = 1/3/3 to 5 / 11
The lubricating oil according to claim 1, 2, 5, 6, 8 or 9. 12. The reaction molar ratio of the aminopolyol represented by the general formula (E), the dialkyl carbonate and the monohydric alcohol is aminopolyol / dialkylcarbonate / monohydric alcohol = 1/4/4 to 5/18/14. The lubricating oil according to any one of claims 1, 2, 7, 8 and 9.