KR20020092976A - Multipurpose lubricant based on phosphorus and sulphur compounds - Google Patents

Abstract

The present invention comprises at least one phosphate ester (A) of formula (I) or a salt thereof, and at least one polysulfide compound (B) of formula: wherein the volume ratio is from 0.01 / 1 to 1/1 It is about a multipurpose lubricant:

[Formula I]

Wherein k is 2 or 3, m is 0 to 8, x is 1 or 2, R represents a straight alkyl or alkenyl radical having 10 to 20 carbon atoms,

[Formula B]

Wherein y is 2 to 8 and R 'represents a tert-alkyl radical having 4 to 18 carbon atoms.

Description

Phosphorus compound and sulfur compound type general purpose lubricant {MULTIPURPOSE LUBRICANT BASED ON PHOSPHORUS AND SULPHUR COMPOUNDS}

The present invention relates to the field of lubricants, more particularly to the field of additives which can be used in industrial lubricating formulations, such as gearboxes, gearings, bearings, compressors, turbines, hydraulic fluids, or lubricating formulations for the processing or shaping of metals. .

Lubricant additives are typically classified into three main groups. Boundary additives or lubricants, typically compounds containing fatty chains and polar groups (such as fatty chains), allow for lubrication under conditions of low load, which form monomolecular coverings on the surfaces to be lubricated to reduce friction and Reduces wear As the friction conditions become more severe, an increase in temperature results in the desorption of such so-called boundaries or lubricity additives, so that anti-wear (AW) or extreme pressure (EP) additives are needed to lubricate the contact surfaces. AW and EP additives are typically compounds comprising phosphorus, chlorine or sulfur. Under high loads, the AW additive can significantly reduce the wear of the parts upon contact, while the EP additive can prevent welding and sticking, but can produce some wear. Efficient lubricating formulations should include additives that can be lubricated under three systems (boundary, AW and EP), which are called multipurpose lubricants.

Until the 1990s, chlorinated paraffins were widely used due to their AW and EP spectra, but their use has tended to decrease considerably for reasons of toxicity.

For example, sulfur compounds such as polysulfides, sulfided olefins or sulfided fatty materials have been used for a long time because of their EP capabilities, which can lubricate under high load and / or high temperature conditions. The sole use of sulfur compounds alone results in good EP properties but too much wear. In addition, many sulfur derivatives are not suitable for lubricating yellow metals (copper, copper alloys, etc.) due to their corrosive effect.

The AW action of phosphorus derivatives is well known. It is usually a phosphite or phosphate ester (a mixture of mono- and diesters obtained by the reaction of alcohols with P ₂ O ₅ or triesters obtained by the reaction of PCl ₃ with alcohols). The sole use of phosphorus compounds alone results in a strong reduction in wear, but it is impossible to obtain a system with very stringent friction conditions.

Combinations of sulfur and phosphorus compounds have already been recommended in patents US 3,933,658, DE 2,752,218 and JP 54-154405, which makes it possible to obtain lubricants with AW and EP properties. However, such compositions are typically not lubricating and require the addition of fatty materials in order to avoid stick-slip phenomena and to reduce friction under conditions of lowering and / or temperature. In addition, phosphorus and sulfur compound based compositions often cause problems of corrosion on the yellow metal due to the presence of sulfur compounds.

Combination of phosphate esters and di-tert-alkyl polysulfides on ethoxylated or non-ethoxylated linear fatty alcohol bases to prevent corrosion of yellow metals in the case of polysulphides lacking free sulfur (ASTM Standard D-1662) It has now been found that it is possible to obtain good multipurpose lubricants (boundaries, AW and EP).

Accordingly, the subject of the present invention is that compound A is a phosphate ester of formula (III) or a salt thereof, compound B is a polysulfide of formula (A), and the mass ratio of A / B is from 0.01 / 1 to 1/1, preferably from 0.05 / It is a multipurpose lubricant comprising at least one phosphorus compound (A) and at least one sulfur compound (B), characterized in that from 1 to 0.4 / 1:

Wherein k is 2 or 3, m is 0 to 8, x is 1 or 2, R represents a straight alkyl or alkenyl radical having 10 to 20 carbon atoms,

Wherein y is 2 to 8 and R 'represents a tert-alkyl radical having 4 to 18 carbon atoms.

Another subject of the invention is that a mixture of at least one phosphate ester (A) or salt thereof as described above and at least one polysulfide (B) as described above is preferably from 0.01 / 1 to 1/1, preferably It is an additive for general purpose lubricant comprised from A / B mass ratio of 0.05 / 1-0.4 / 1.

Among the phosphate esters (A), phosphate esters (A) wherein k is 2, m is 2 to 6 and R is a radical having 12 to 18 carbon atoms, more specifically lauryl, stearyl, oleyl or linoleyl radicals Is preferred. Phosphoric acid esters (A), typically mixtures of mono- and diesters having a ratio of 10/90 to 90/10, can be used in acid form or in the form of alkali metal, ammonium or alkanolamine salts.

Among the polysulfides (B), those in which y is 3 to 5 and the R 'radical contains 4 to 12 carbon atoms are preferable. Di-tert-butyl trisulfide, di-tert-nonyl pentasulfide, di-tert-dodecyl trisulfide and di-tert-dodecyl pentasulfide are more particularly preferred.

The additives according to the invention can be prepared simply by mixing the compounds (A) and (B), which are usually liquid at room temperature. In some cases, work can be facilitated by heating.

The multipurpose lubricant according to the present invention may contain 1 to 100 parts of additives per 100 parts of oil, preferably 2 to 50, more specifically 5 to 20, of the additive of the present invention to whole or soluble oils. Can be obtained by introduction. The oil may be mineral or synthetic or animal or vegetable, and may include additives commonly used in lubricants such as lubricants, corrosion inhibitors, emulsifiers, alkalis and the like.

Example

In the following examples, the examples illustrate the invention without limitation, and the parts and percentages shown are by weight. The names and chemical properties of the compounds used in the examples below are detailed in Table 1 below.

Type of product Name chemistry Mineral oil 100NSO3 Paraffin Wax, 100 Neutral Phosphorus compounds Beycostat A684 Phosphoric Acid Ester of Oleyl Alcohol Containing 4.5EO * Beycostat A244 4 Phosphoric Acid Ester of Lauryl Alcohol Containing EO Beycostat AB04 4 Phosphoric Acid Ester of Nonylphenol Containing EO Beycostat A136 Phosphate esters of isotridecyl alcohol containing 6 EO Beycostat A130 Phosphate Ester of Iso-tridecyl Alcohol Beycostat A081 Phosphate Ester of Ethylhexanol Sulfur compounds TPS 20 D-tert-dodecyl trisulfide TPS 32 D-tert-dodecyl pentasulfide TPS 37 Di-tert-nonyl pentasulfide TPS 44 Di-tert-butyl trisulfide * EO = ethylene oxide

Phosphoric acid esters marketed by the present applicant company mainly consist of monoesters. Polysulfide TPS 20, TPS 32, TPS 37 and TPS 44 are commercially available from ATOFINA.

The performance of the lubricant was evaluated according to the following experimental procedure.

4-ball extreme pressure test (ASTM D-2783):

Evaluation of the anti-wear capacity by the maximum possible value of the load before loading (typically ≥100 kg) and the extreme pressure capacity by the maximum possible value of the welding load (typically ≥315 kg).

Condition: 1500 rev / min, incremental dropping for 10 seconds.

2. 4-Ball Wear Test (ASTM D-4172):

Evaluation of the antiwear performance by the minimum possible value of the wear trace (typically ≤0.60 mm).

Conditions: 1500 rev / min, 40 kg, 3600 seconds, 75 ° C.

3. Ball-disk test:

Evaluation of the lubricity or boundary ability of the lubricant by the value of the friction coefficient μ (typically ≤0.05) which should be as low as possible.

The ball-disk test consists of spinning the disk at constant speed under a ball under constant load. Dip the disc and the ball into the lubricant. The coefficient of friction of the ball-disk lubrication contact is measured with a force sensor.

Conditions: 1 rev / min, 1 kg, 30 minutes, 100C6 steel ball on aluminum 3104 disc.

4. Corrosion Resistance to Copper Strips (ASTM D-130):

Because the sulfur additives tend to corrode the yellow metal due to the presence of free sulfur, this test evaluates the corrosiveness of the formulation against copper strips.

The test consisted of immersing a polished copper plate in a test tube containing 30 ml of formulation at 60 ° C. for 24 hours. At the end of the test period, the copper plates are properly cleaned and compared with the reference corrosion strip (range of classification: 1a (minimum corrosion) to 4c (maximum corrosion)).

The 27 additive compositions prepared from the products described in Table 1 are summarized in Table 2 below.

Only compositions 6-15 and 17 are the compositions according to the invention. Other compositions contain no phosphorus compounds (compositions 1 to 4), no sulfur compounds (compositions 5, 16, 18, 20, 22 and 24) or include phosphorus compounds derived from non-linear alcohols (compositions 19, 21, 23 and 25 to 27).

Examples 1 to 30

The composition of Table 2 was diluted in 100 Neutral whole paraffin oil and the performance of the formulation thus obtained was compared to Table 3 below, with the percentage of dilution representing the proportion of the additive composition in the formulation.

Investigation of the results in Table 3 found that the choice of phosphate esters was critical, as the lubricants of Examples 24, 26, 28 and 30 comprising esters not according to the invention had a high coefficient of friction (> 0.05), ie lubricity Because of the lack of. In addition, it was observed that corrosion to yellow metal was suppressed when the polysulfide did not contain free sulfur (Examples 7, 10 and 13).

Examples 31-39

The additive compositions 5, 7, 9, 12, 13, 16, 18, 26 and 27 of Table 2 were dispersed in water to prepare nine lubricants whose performance is compared to Table 4 below.

Examples 31 to 33 correspond to phosphorus compounds dispersed alone in water. Examples 34 to 37 are in accordance with the present invention. Examples 38 to 39 are not in accordance with the present invention.

Examples 40-44

Unadded microemulsion (Example 40) was prepared with 5% 100 Neutral paraffin oil, 9.5% polyethoxylated (4 EO) lauryl alcohol, 0.5% sodium dodecylbenzenesulfonate and 85% water. .

The additive compositions 1, 2, 5 or 7 of Table 2 were added successively to the samples of the microemulsion, and then the mixture was heated to 50 ° C. to homogenize.

The performance of the lubricant obtained above which was translucent at room temperature was compared to Table 5 below.

Claims (12)

Compound A is a phosphate ester of formula (I) or a salt thereof, Compound B is a polysulfide of formula (I) and the mass ratio of A / B is 0.01 / 1 to 1/1, wherein at least one phosphorus compound (A ) And one or more sulfur compounds (B): [Formula A] Wherein k is 2 or 3, m is 0 to 8, x is 1 or 2, R represents a straight alkyl or alkenyl radical having 10 to 20 carbon atoms, [Formula B] Wherein y is 2 to 8 and R 'represents a tert-alkyl radical having 4 to 18 carbon atoms. The lubricant of claim 1 wherein k is 2, m is 2 to 6 and R is a radical having 12 to 18 carbon atoms. The lubricant according to claim 1 or 2, wherein y is 3 to 5 and R 'is a tert-alkyl radical having 4 to 12 carbon atoms. The lubricant according to any one of claims 1 to 3, wherein the A / B mass ratio is 0.05 / 1 to 0.4 / 1. The compound of claim 1, wherein A is a mixture of mono- and diester phosphates, k is 2, m is 4-5, and R is lauryl, stearyl, oleyl or linoleyl. A lubricant that is a radical. The compound B according to any one of claims 1 to 5, wherein the compound B is di-tert-butyl trisulfide, di-tert-nonyl pentasulfide, di-tert-dodecyl trisulfide and di-tert-dodecyl A lubricant that is pentasulfide. At least one phosphate ester (A) of formula (I) or a salt thereof, and at least one polysulfide (B) of formula: wherein the mass ratio of A / B is 0.01 / 1 to 1/1 Multipurpose Lubricant Additives: [Formula A] Wherein k is 2 or 3, m is 0 to 8, x is 1 or 2, R represents a straight alkyl or alkenyl radical having 10 to 20 carbon atoms, [Formula B] Wherein y is 2 to 8 and R 'represents a tert-alkyl radical having 4 to 18 carbon atoms. 8. The additive of claim 7, wherein k is 2, m is 2 to 6 and R is a radical having 12 to 18 carbon atoms. 9. The additive of claim 7 or 8, wherein y is 3 to 5 and R 'is a tert-alkyl radical having 4 to 12 carbon atoms. 10. The additive of any one of claims 7-9, wherein the A / B mass ratio is 0.05 / 1 to 0.4 / 1. The compound of claim 7, wherein A is a mixture of mono- and diester phosphates, k is 2, m is 4-5, and R is lauryl, stearyl, oleyl or lino. An additive that is a rail radical. The compound B according to any one of claims 7 to 11, wherein the compound B is di-tert-butyl trisulfide, di-tert-nonyl pentasulfide, di-tert-dodecyl trisulfide and di-tert-dode Additives that are seal pentasulphides.