JPS5829839B2 - Jiyunkatsuyuso Saibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lubricating oil composition containing a specific acrylic acid ester sulfide as an extreme pressure agent.

Such lubricating oil compositions exhibit extreme pressure lubricity and are useful as cutting oils, as well as for lubricating the moving parts of power transmissions, gear systems, and engines, particularly internal combustion engines.

Metal cutting oil must be light in color because it is necessary to carefully observe the material to be cut during operation.

Further, it is desirable that the cutting oil has a pleasant odor, or at least a mild odor, from the viewpoint of the health of the workers and the need to make the work comfortable.

Moreover, the cutting fluid must provide extreme pressure lubrication to the cutting tool so that it can be used for as long as possible between resharpenings or replacements.

If workers are not exposed to the vapors generated by the cutting oil and there is no need to observe the parts being lubricated, the color and odor of the cutting oil may be affected by extreme pressure lubrication and acid spreading properties. It's not an important issue.

However, odor and appearance are important to those who manufacture lubricating oil additives, compound oils, and handle used oils as is.

olefinic compounds such as sulfur and pyrolytic waxes,
The reaction product with lard oil or whale oil has a dark brown or black color even when diluted with oil to the final use level.

Moreover, these reaction products have hydrogen sulfide-like and by-product mercaptan-like odors.

Traditionally, light-colored, mild-odor sulfur compounds used in cutting oils have been produced by treatment with sodium polysulfide followed by chlorination or sulfochlorination.

Such indirect multi-stage reaction processes are too expensive to produce and the cutting fluids produced by this method are therefore expensive.

There is a need for a light-colored, mild-odor lubricating oil produced from inexpensive raw materials by an inexpensive process, preferably a one-step process.

The present invention satisfies these requirements. Smith (Sm
1th) U.S. Patent No. 2,683,119
The issue describes compositions that impart oiliness and film strength to lubricating oils.

This complex acid has at least two carboxylic acid groups and at least one thiol-bonded sulfur atom.

All of the acids exemplified as suitable for this composition contain allylic hydrogen atoms.

U.S. Pat. No. 3,740,333, invented by Hutchinson et al., teaches useful compositions as an alternative to peppered whale oil.

This composition is a blend of triglycerides and wax esters.

The wax esters are derived from unsaturated fatty acids having 18,20 or 22 carbon atoms.

Triglycerides are also made from the same fatty acids.

The blend of wax ester and triglyceride described above is subjected to a sulfurization reaction by conventional methods.

According to the present invention, sulfides of esters selected from the group consisting of 2-lower alkylhexyl acrylates, lower alkyl acrylates and lower alkoxy lower alkyl acrylates are suitable for use in lubricating oils and metal working oils and metal cutting oils. Now discovered as an additive.

A preferred embodiment thereof provides a mixture of sulfides and sulfochlorides, which mixture has a synergistic effect in reducing and improving drilling torque.
tic).

(4) a major amount of an oil of lubricating viscosity; (B) in an amount of about 0.1 to 20% by weight of the composition;
The present invention provides a lubricating oil composition comprising a sulfide of an ester selected from the group consisting of 2-lower alkylhexyl acrylate, lower alkyl acrylate, and lower alkoxy lower alkyl acrylate, which imparts extreme pressure properties to the oil.

Lubricating oil compositions containing these ester sulfides have a relatively light color and a mild odor.

Furthermore, since almost no hydrogen sulfide is generated during the production of the ester sulfide, the production of by-products that cause air pollution can be prevented.

Compositions suitable as additives for use in lubricating oils and metal working and cutting oils are those containing allylic hydrogen-free acrylic acid ester sulfides.

The lubricating oil compositions of the present invention contain (4) a majority of the oil of lubricating viscosity and (B) an effective amount of sulfides of said esters which impart useful effects to said oil, such as extreme pressure properties and anti-wear properties. Consists of.

The above-mentioned ester, which is a raw material for the ester sulfide, is produced from acrylic acid and the alcohols described below, but neither the carboxylic acids nor the alcohols contain an allylic hydrogen atom.

Carboxylic Acids As mentioned above, the esters mentioned above are prepared from allylic hydrogen-free acrylic acid.

Allylic hydrogen atoms are well known to those skilled in the art.

That is, an allylic hydrogen atom is a hydrogen atom bonded to a saturated carbon atom at the alpha position connected to a double bond.

An example of this is shown in equation (1) below. In formula (I), hydrogen atoms marked with * are allylic hydrogen atoms.

An example of a carboxylic acid containing no allylic hydrogen is acrylic acid (CH2=CHCOOH).

An example of a carboxylic acid containing allylic hydrogen is methacrylic acid (CH2-C(CH3)-C00H).

In this methacrylic acid, the methyl group bonded to the alpha carbon atom is a saturated carbon atom, and a hydrogen atom is bonded to this methyl group.

Acrylic acid is bonded to this saturated carbon atom at the alpha position of the double bond, and therefore the hydrogen atom bonded to the methyl group is an allylic hydrogen atom.

Of course, it is also possible to use the anhydrides and acid halides of the acrylic acids mentioned above for the purpose of producing the esters used in the sulfurization reaction, and the present invention also covers the use of these acid anhydrides and acid halides. It is intended.

Alcohols Suitable alcohols generally useful in preparing the lubricating oil compositions of the present invention are represented by formula (IV) below.

In the formula, R represents a moiety other than the hydroxyl group of the alcohol, and is a lower alkyl group, a 2-lower alkylhexyl group, or a lower alkoxy lower alkyl group.

Suitable alcohols include methanol, ethanol, propatool, impropatol, butanol, isobutanol, 5ee-butanol, t-butanol, pentanol, 2-ethylhexanol, ethoxyethanol and the like.

Esters The aforementioned esters used in the lubricating oil compositions of the present invention are prepared from the aforementioned acrylic acids and the aforementioned alcohols.

Methods for producing these esters are methods known to those skilled in the art.

These methods include, for example, the direct combination of acids and alcohols;
In some cases mineral acids are used as catalysts to accelerate the reaction.

The water produced as a result of the reaction is removed to complete the reaction.

In other methods, acid halides or acid anhydrides can also be reacted with alcohols.

The method of preparing the ester is not relevant to the subject matter of the present invention and will not be described further.

Acrylic esters useful in the present invention are 2-lower alkylhexyl acrylate, lower alkyl acrylate, and lower alkoxy lower alkyl acrylate.

Preparation of Ester Sulfides The sulfurization reaction of the esters mentioned above is generally not difficult and can be achieved simply by bonding elemental sulfur, sulfur chloride or sulfur dichloride to the esters mentioned above.

The sulfidation reaction can be carried out at any temperature such that the reaction proceeds below the decomposition temperature of the reactants or reaction products.

Generally, it is desirable to carry out the reaction at high temperature in order to increase the reaction rate.

The reaction between sulfur and the ester is preferably about 10-
Preferably, the temperature is 200°C, particularly 120-200°C.

The reaction generally lasts from 0.5 to 48 hours, preferably from 2 to 24 hours.

The reaction of the ester with sulfur chloride or sulfur dichloride proceeds more easily than the reaction of the ester with elemental sulfur.

This reaction proceeds at a temperature of 60-200°C, preferably 80-180°C.

The reaction generally takes about 0.5-48 hours, preferably 2-36 hours.
Lasts for hours.

The molar ratio of sulfur or sulfur chloride to the ester can vary over a wide range.

For this purpose it is convenient to calculate the number of moles of sulfur or equivalents of sulfur present in sulfur chloride used per mole of olefinic bonds present in the ester.

The ratio of sulfur to olefinic bonds ranges from 0.5-2:1, preferably 0.751.521.

A molar ratio of approximately 1=1 is desirable because this molar ratio allows for a high concentration of sulfur in the reaction product without leaving excess free sulfur in the reaction product by allowing the reactants to stand. This is because it is possible.

Most of the aforementioned low molecular weight esters are liquid at room temperature or at least at the reaction temperature.

That is, no reaction solvent is required.

Generally, the ester and sulfur or sulfur chloride are simply mixed in a reaction vessel and the reactants are heated to the desired temperature with stirring.

Stirring and heating are continued during the reaction, and then the reaction product is allowed to cool to room temperature.

After cooling the reaction to room temperature, the reaction is allowed to stand for 1-3 days to allow unreacted excess sulfur to settle out.

The reaction is filtered to remove this sulfur.

The filtered reaction product can generally be formulated without further purification into lubricating oils used for the lubrication of moving parts of machinery and as cutting fluids in metal processing.

For esters that are not liquid at room temperature, the use of a reaction solvent is generally desirable.

Reaction solvents suitable for use include any solvent that is compatible with the ester, is soluble in the ester, and does not inhibit the sulfidation reaction.

That is, the use of solvents containing double bonds, particularly allylic hydrogen atoms, must be avoided since they may generate hydrogen sulfide and color the reaction product darkly.

When the sulfurization reaction product is liquid at room temperature, a petroleum fraction with a low boiling point can be used as the reaction solvent because it can be easily removed after the sulfurization reaction.

If the reaction product is not liquid at room temperature, it is generally difficult to completely remove the reaction solvent.

In the latter case, it is desirable to use a high-boiling petroleum distillate as the reaction solvent, especially one having a boiling point range and viscosity range similar to that of the lubricating oil to which the ester sulfide is to be added.

The ester sulfide diluent thus becomes a component of the final lubricating oil composition.

When a reaction solvent is used, whether it is a low-boiling reaction solvent that is removed after the reaction is complete or a high-boiling petroleum distillate that is not removed, the amount of solvent used is controlled to increase the concentration of the reactants. It is desirable to use as little amount as possible.

A higher concentration of reactants not only improves the reaction rate but also increases the capacity of the reactor.

Ester sulfides, especially those made from low molecular weight carboxylic esters, such as alkyl acrylates, are liquid at room temperature, have a viscosity low enough to be pumped at room temperature, and are easy to handle at room temperature.

Additionally, these ester sulfides are easily miscible with lubricating oils.

The ester sulfides are also relatively light in color, especially after dilution to normal working concentrations, and are lighter in color than conventional sulfide compounds prepared by direct reaction with sulfur.

Moreover, the ester sulfides have a mild, pleasant odor.

Lubricating and Cutting Oils When the ester sulfides of the present invention, which are liquid at room temperature, are used in metal cutting and machining operations, it is most practical and economical to use them diluted with inexpensive oils.

Oils suitable as diluents are preferably those suitable for use as lubricating oils and cutting oils.

The ester sulfide of the present invention is added in an effective amount to impart extreme pressure lubricity to the lubricating oil in the lubricating oil, metal working oil, and cutting oil of the present invention.

Generally, the effective amount of ester sulfides in the oil ranges from about 0.1 to about 20% by weight, preferably from about 0.5 to about 15% by weight, and more preferably from about 1 to 10% by weight.

When applied to cutting oils, ester sulfides are added to the oil to give it a specific sulfur content.

The cutting oil has a sulfur content of about 0.1-10% by weight, preferably about 0.5-5% by weight, especially about 0.5%. −
2% by weight is desirable.

The ester sulfides described above can be produced as highly concentrated products.

This highly concentrated product is formulated with diluent oil prior to final use.

Among the above ester sulfides, those that are liquid at room temperature are generally produced without a reaction solvent, so high concentration products are
Contains 0% ester sulfide.

Adding diluent oil to these highly concentrated products merely increases shipping costs and generally has no benefit other than ease of handling.

Among these ester sulfides, those that are not liquid at room temperature,
Alternatively, those with very high viscosity at room temperature can be manufactured as highly concentrated products.

In order to keep shipping costs to a minimum, the amount of diluent oil in these highly concentrated products must be kept to a minimum.

Generally, the concentration of ester sulfide is from about 20 to about 90% by weight, with products desirably having a concentration of at least 50%.

Lubricating oil compositions produced according to the present invention include oils of lubricating viscosity.

This oil should be of a viscosity suitable for the purpose of the final composition.

Petroleum base oils of naphthenic or paraffinic, unrefined, acid-treated, solvent-refined or hydrocracked lubricant portions are generally known to meet specific lubrication or cutting purposes.

Synthetic oils meeting the required viscosity requirements and with or without viscosity index improvers or other additives can also be used as base oils.

The viscosity of the lubricating or cutting oil can be selected from a wide range of viscosity depending on the purpose.

By selecting appropriate base oils, mixing different base oils, and/or incorporating various viscosity index improvers available on the market into these base oils or base oil mixtures, the required specifications can be achieved. The production of lubricating oil compositions is well known to those skilled in the art.

In addition to the ester sulfides described in this invention, the oils mentioned above,
In particular, lubricating oils contain a variety of well-known materials that are useful when formulating and preparing lubricating oils, such as dispersants, detergents, extreme pressure agents, and viscosity index improvers, in order to meet various standards required depending on specific uses. may contain additives.

For metal working operations, the compositions of the invention can be applied to the metal to be worked prior to a suitable process such that contact with the metal surface is complete.

For example, the composition can be brushed or sprayed onto the metal surface, or the metal can be immersed in a bath of the lubricating oil composition.

The following examples are included for a better understanding of the invention.

Example 1 8421 (4,5
76 mol) of 2-ethylhexyl acrylate and 1
46P (4,576 moles) of elemental sulfur was added.

The reactants were heated to 160°C in a nitrogen stream with stirring.
After reacting for 1 hour, the reactants were cooled to room temperature (Celai).
(Celite) 545 was used.

955 tons of lachrymal fluid with a sulfur content of 14.0% by weight was collected.

Example 2 In 11 resin flasks equipped with the same equipment as in Example 1, 1
84f (1 mole) of 2-ethylhexyl acrylate and 32P (1 mole) of elemental sulfur were added.

The reactants were heated to 160°C with stirring under a stream of nitrogen and held at 1600-170°C for 14 hours.

Reactant τ cooled, filtered and product 206 with a sulfur content of 13.5% by weight? I got it.

Butyl acrylate sulfide was prepared from butyl acrylate and elemental sulfur by a similar method.

The resulting reaction product contained 20% by weight of sulfur.

In a similar manner, cellosolve acrylate (ethoxyethyl acrylate) was sulfided with elemental sulfur to obtain a reaction product with a sulfur content of 17.7% by weight.

Example 3 In 11 resin flasks equipped with the same equipment as in Example 1, 3
68P (2 moles) of 2-ethylhexyl acrylate was added.

While stirring, 135 f (1 mole) of -sulfur chloride was added dropwise from the dropping funnel over a period of 20 minutes.

No exothermic phenomenon was observed. The reaction was heated to 120° C. under a nitrogen stream while stirring, and this temperature was maintained within ±5° C. for 22 hours.

After completion of the reaction, the reaction product was cooled to room temperature and filtered under reduced pressure to obtain a chlorine content of 10.99% by weight and a sulfur content of 767% by weight.
4532 tears were obtained.

The p-filtered residue was 27 grams, containing 97.1% by weight of sulfur, and the content of chlorine was 0.2% by weight or less.

The melting point of this p-filter residue was 113-114°C.

Example 4 A. Commercially available sulfur dichloride was chlorinated by the following method to ensure purity.
5352f of sulfur dichloride obtained from S.Y.) was placed in a large container and cooled to 10°C, to which 363 g of chlorine was added over 3 hours and the temperature was maintained at 8-10°C.

B, 20,000 r of 2-ethylhexyl acrylate was placed in a large container equipped with a stirring device and a heating device.

If A'' reaction product 56055' was added under stirring for 15 minutes.

This temperature was 23.9°C.

After 15 minutes, the temperature rose to 76.7°C.

After an additional 13 minutes, the temperature rose to 111.1°C, and over the next 7 minutes the temperature fell to 108.9°C.

The reaction mixture was then heated to about 130°C and held at that temperature for 24 hours with stirring.

The reaction mixture was cooled to 15.6°C and filtered through a 3 micron cartridge type filter.

The yield of the product obtained is 237705', and the sulfur content is 6
．． The chlorine content was 41% by weight, and the chlorine content was 11.2% by weight.

EXAMPLE 5 Drilling Torque Test In order to test the properties of the reaction product prepared as described above as a cutting fluid additive, a Drill Torque Test was conducted.

In this test, various loads were applied to the drill, pressure was applied, and
Experiments were carried out at various rotational speeds.

The drilling torque measurement system consists of a rotating sample holder, a table, a torque arm strain gauge, a rondo cell, and a recorder.

Drill bits are high speed steel, joppers length (
3/8 diameter with a drill
An inch and a cutting angle of 13o0 were used.

The drilling samples were blocks of 304 stainless steel measuring 6 inches by 6 inches by 1'-inch.

The torque measurement system was zeroed prior to testing to set the final stop torque to 110 in-lbs.

A precision ground drill was mounted firmly enough in the drill press chuck.

The drill delivery rate was set at 0.014 inches per revolution.

The drill press was adjusted to the desired rate per revolution and the oil pump was started.

The drill was lowered manually until it almost touched the sample block.

Next, I drilled the holes with an automatic feed switching drill.

Once the hole had been drilled, the drill was raised, the sample block was rotated, and a new hole was drilled.

In this method, the drilling torque is 110 at the specified rotation speed.
Continue until the -inch-pound limit is exceeded or until 50 holes have been drilled with one drill bit.

Table 1 shows comparative test results of various sulfides produced by the method of the present application and commercially available cutting oil additives.

The table also shows the results of tests conducted on combinations of esters sulfurized with elemental sulfur, sulfurized with sulfur chloride, and sulfurized with sulfur dichloride.

As seen from the above data, it is clear that the ester sulfide of the present invention provides excellent properties to metal cutting fluids.

In particular, 2-ethylhexyl acrylate sulfide has shown very superior properties in drilling torque tests compared to commercially available cutting oil additives, and esters sulfurized with elemental sulfur alone and esters sulfurized with sulfur chloride. The combination with sulfide is superior to the case of each sulfide alone.

This drilling torque test method correlates well with actual cutting work results, and was discovered through extensive experience in conducting various tests.

Example 6 A variety of the carboxylate sulfides described above were tested to demonstrate their effectiveness as motor oil additives.

Copper piece corrosion test This copper piece corrosion test shows the corrosivity of lubricating oil to non-ferrous metals.

In this test, a copper strip is immersed in a lubricating oil composition containing the additives to be tested.

This lubricating oil composition is held below 250°C (121'C) for 3 hours.

The degree of discoloration of the copper pieces tested was determined using a colorimetric chart (Compa
rison Chart).

A rating designated as 1a indicates a very low degree of discoloration and therefore indicates a very low corrosiveness of the lubricating oil composition to copper.

A high rating such as 2b or 2a indicates a higher reactivity of the composition, which is required for oils used under high load conditions.

For more information regarding this test, please refer to ASTM Test 1 Test Method D-130 (
ASTM Test Method D-130).

Table 2 shows the copper piece corrosion test results for the composition of the present invention.

Oxidator B test The stability of lubricating oil compositions against oxidation is 340'F for 1001 test oil.
This can be determined by measuring the time required to consume 11 oxygen at (171'C).

For convenience, 25P was used as the test oil in the actual test, and the test results were adjusted to the values obtained when a 10M' sample was used.

During the test, 95 ppm copper, 80 ppm iron, 4.8 ppm manganese, 1 l 100 ppm lead, 49
A mixture of oil-soluble metal salts giving ppm of tin is added to the oil.

Table 2 shows the results of testing the lubricating oil composition of the present invention in the oxidation tester B test.

Four-Ball Wear Test The wear resistance of lubricating oil additives under boundary lubrication conditions can be measured by the well-known four-ball test.

In this test, three 1/2 inch diameter steel balls are secured together and immersed in a lubricant sample.

A fourth steel ball is brought into contact with the three fixed steel balls at about 1 soo rotation per minute.

A predetermined load, in this case 20 kg, is applied to the fourth steel ball, which is rotating relative to the three fixed steel balls.

The test is conducted for 60 minutes, the wear marks marked on three fixed steel balls are measured, and the average value of the mark length is reported in mrn.

The smaller the wear marks, the greater the wear resistance of the lubricant.

For example, base oil usually shows 0.00 wear marks under a load of 20 kg.
60mm or larger.

Generally speaking, a lubricant that produces wear marks smaller than 0.5 mm under a load of 20 kg is considered to have acceptable wear resistance; It is believed that lubricants that provide this have very good wear resistance.

Table 2 shows the results of testing the lubricating oil composition of the present invention in a four-ball test.

Falex Extreme Pressure Test The properties of lubricating oil compositions under extreme pressure can be determined with this test.

Falex Extreme Pressure Testing Machine
) is a 7-engine building company located in Chicago, Illinois.
porationof Chicago, l1li
manufactured by Nois).

In this test, blocks with two opposing V-shaped grooves are moved toward each other using a lever in a nutcracker-like mechanism.
A rotating steel shaft inserted into a V-shaped groove is pressed against it.

The rotating shaft is rotated by a chuck via a bronze shear pin.

A V-groove block and pin specimen is immersed at a predetermined temperature into a container of the lubricant to be tested.

The test machine is operated at 290 revolutions per minute and the specimen breaks under a load of 300 pounds.

During the test, the load between the V-groove block and the rotating pin is automatically increased until wear marks appear.

The point of failure is shown for shearing of the bronze pin holding the rotating shaft.

The load at failure, expressed in pounds, represents a quantitative measure of the extreme pressure properties of the lubricating oil compositions tested.

Mineral oils reach failure point at a load of 600-900 pounds.

Lubricants with moderate extreme pressure additives are 1000-2000
The failure point is reached at a load of 3,000 pounds, and the most effective extreme pressure additives tolerate loads of 3000 pounds or more.

The load limit for this tester is 4500 pounds.

The results of this test for the lubricating oil composition of the present invention are shown in Table 2.

A lubricating oil composition according to the invention was prepared from butyl acrylate sulfide containing 20% by weight sulfur and 2-ethylhexyl acrylate sulfide containing 19% by weight sulfur.

The above sulfide additive is 480SUS in 1001-
(Seybold Universal Sec.) was added to the base oil, which is a solvent-refined neutral oil with a viscosity of 100 sec.

This base oil contains a substituted succinic anhydride having a polybutenyl group as a substituent having an average molecular weight of about 95Q, and tetraethylenepentamine in a molar ratio of tetraethylenepentamine to amine per mole of the succinic anhydride. Approximately 0.8
Contains 6% by weight of polyimbutenyl succinimide produced by reacting so as to have a composition of 7.

The base oil also contains 0.1% by weight of telephthalic acid.

Table 2 shows the Farek test results for this test oil.

As is clear from the above data, the lubricating oil compositions of the present invention provide excellent antioxidant properties, anti-wear properties, and extreme pressure properties.

However, its corrosiveness to copper is somewhat high, but not more corrosive than that of lubricating oils containing some sulfur, which are used as good motor oils.

Example 7 Bearing Weight Loss Test The lubricating oil composition of the present invention was tested in the L-38 Bearing Weight Loss Engine Test Method.

In this test, 6% by weight of the same polyisobutenyl succinimide as used in Example 5 above, 0.1% by weight of terephthalic acid, 0.8% by weight of tetrapropenyl succinimide, and sulfur in polysulfide sulfide (sulfur content 17%) were used. .5%) 1.0% by weight, 2-ethylhexyl acrylate sulfide (sulfur content approx. 1
A lubricating oil containing 1.5% by weight (9% by weight) and 0.1% by weight of benzotriazole as copper deactivator was used.

In this test, the copper piece corrosion rating of this test oil was 3a.
was a significant improvement over the 4C rating shown in Table 2, and the bearing weight loss was 331n9 after 40 hours.

In this test, a bearing weight loss of 40771 or less after 40 hours of operation is acceptable.

Example 8 Example 6 was repeated for a lubricating oil composition of the present invention.

No additives were added to the base oil in this series of tests.

The base oil used was a solvent-refined neutral oil with a viscosity of 48O3US at 100'F.

The test results are shown in Table 3. As shown in the above data, the lubricating oil composition of the present invention exhibits excellent antioxidant properties, wear resistance, and extreme pressure lubricity.

Claims (1)

Claims: 1 (A) a major amount of an oil of lubricating viscosity; (B) in an amount of about 0.1 to 20% by weight of the composition;
and a sulfide of an ester selected from the group consisting of di-lower alkylhexyl acrylate, lower alkyl acrylate, and lower alkoxy-lower alkyl acrylate.