JP2011514912A - Method for producing lubricating composition - Google Patents

Abstract

The present invention includes (a) a step of supplying a base oil composition optionally containing one or more additives, (b) a step of supplying a solvent solution of one or more alkyl-substituted quinolines or oligomer derivatives thereof, and ( c) A method for producing a lubricating composition, particularly a grease, comprising the step of adding the solution of step (b) to the base oil composition of step (a) at a temperature below 150 ° C.
[Selection figure] None

Description

  The present invention relates to a method for producing a lubricating composition, particularly a grease.

  Alkyl-substituted quinolines and polymerized derivatives thereof are known as antioxidants that are extremely effective and inexpensive for various uses including use in lubricating compositions.

  As an example, International Publication No. 94/24235 discloses an alkyl-substituted 1,2-dihydroquinoline (monomer, its dimer, trimer) for motor oil, transmission oil, gear oil, metal squeezed oil, hydraulic oil, grease, etc. And tetramer). Specific examples of these alkyl-substituted 1,2-dihydroquinolines include 2,2,4-trimethyl-1,2-dihydroquinoline, 2-methyl-2,4-diethyl-1,2-dihydroquinoline, 2,2, 4,6-tetramethyl-1,2-dihydroquinoline, 2,2,4,7-tetramethyl-1,2-dihydroquinoline, 6,6′-bis (2,2,4-trimethyl-1,2 -Dihydroquinoline) and the like.

  Further, US Pat. No. 5,246,606 discloses that dimerized, trimerized and tetramerized derivatives of tetrahydroquinoline are suitable for stabilizing organic materials against light-induced, thermal and / or oxidative degradation. U.S. Pat. No. 5,246,606 proposes the use of these compounds among various compounds in functional fluids such as lubricating oils and hydraulic oils.

  Alkyl-substituted quinolines such as 2,2,4-trimethyl-1,2-dihydroquinoline (also referred to as “TMQ”, “TMDQ” and “TMHQ”) and oligomers thereof (ie, dimers, trimers) Bodies and tetramers) are widely used, but they have many disadvantages.

  As an example, TMQ is a brittle solid at room temperature, usually in a mixture of monomers and oligomers, so it does not have a sufficiently limited melting point. This compound softens with increasing temperature, but is still a very viscous and sticky material at about 80-100 ° C., the usual additive addition temperature.

  When TMQ is added to a lubricating composition such as grease at such temperatures typically in the range of 80-100 ° C., it does not disperse well in the grease, resulting in filter clogging, for example in a grease delivery system. Even if the filter load of such a grease delivery system is not sufficient to quickly clog, some amount of this antioxidant is removed from the grease, resulting in a shortened life.

  In view of the above, alkyl-substituted quinolines are typically used at temperatures above 150 ° C., typically 150, after the grease has established a thickener system in the base oil and after completing the critical cooling phase. Added to grease at ~ 160 ° C.

  However, a related problem with this known method is that when the alkyl-substituted quinoline needs to be properly dispersed in the grease, the opportunity for addition is usually narrow. If the alkyl-substituted quinoline is added, for example after 10 minutes, the grease may have been cooled too much, so it may have been too late.

  Another problem with known methods of adding alkyl-substituted quinolines to greases at relatively high temperatures is, for example, more stringent in relation to the danger of hot grease and the risk of fumes when the production container needs to be opened. It is important to consider health and safety issues.

The object of the present invention is to avoid the above problems.
Another object is to provide an alternative method for producing lubricating compositions, particularly greases.

One or more of these or other purposes may include:
(A) providing a base oil composition optionally containing one or more additives;
(B) supplying a solvent solution of one or more alkyl-substituted quinolines or oligomer derivatives thereof; and (c) adding the solution of step (b) to the base oil composition of step (a) at a temperature of less than 150 ° C. The process of
It is obtained by providing a method for producing a lubricating composition comprising at least

  According to the present invention, when the alkyl-substituted quinoline (or oligomer derivative thereof) is added to the base oil composition in a solvent, the alkyl-substituted quinoline can be added at a low temperature while being appropriately dispersed in the base oil composition. It was found unexpectedly.

  An important advantage of the present invention is that alkyl-substituted quinolines (or oligomeric derivatives thereof) can be added at low temperatures, resulting in relaxed stringent safety requirements. Also, since the specific temperature for adding the alkyl-substituted quinoline (or oligomer derivative thereof) is less critical than when no solvent is used, there is more flexibility at the time of addition.

  In step (c), the solution of step (b) is added at a temperature below 120 ° C, preferably in the range of 10 to 110 ° C, more preferably in the range of 15 to 100 ° C.

In a particularly preferred embodiment of the invention, the one or more alkyl-substituted quinolines are alkyl-substituted 1,2-dihydroquinolines (or oligomeric derivatives thereof). Preferably the alkyl substituted 1,2-dihydroquinoline has the general formula (I)

(However, R ^{1 to} R ⁸ are independently selected from hydrogen or an alkyl group having 1 to 8 carbon atoms, and n is 0, 1, 2, or 3)
Have

Preferably R ^{1 to} R ⁸ are independently selected from hydrogen or an alkyl group having 1 to 4, preferably 1 or 2, carbon atoms. Preferably R ⁴ is hydrogen. More preferably, R ^{4 to} R ⁸ are all hydrogen. R ^{1 to} R ³ are preferably all methyl groups.

The average value of n of one or more alkyl-substituted 1,2-dihydroquinolines is 1.0 to 2.0, preferably 1.3 to 1.6.
Also, the solubility of one or more alkyl-substituted quinolines supplied to the solution is preferably less than 0.1% as measured by ASTM D893.

  The alkyl-substituted quinoline compound (or oligomer derivative thereof) used in the present invention can be obtained as a commercial product or can be produced by various reactions known in the art. Examples of production methods are given in the aforementioned WO 94/24235 and US Pat. No. 5,246,606 and references cited in these references (the teachings of these references are also incorporated herein).

A specific example for preparing TMQ (2,2,4-trimethyl-1,2-dihydroquinoline) is R. Vaughan, “Organic Synthesis”, Collective Volume III, pp 329-30, (1955).
There are no particular limitations on the solvent used in the method of the present invention, and various conventional solvents can be conveniently used.

The solvent preferably includes polyglycol, more preferably polyalkylene glycol. Polyglycols are well known in the art and will not be discussed further here.
As an example, polyalkylene glycol (PAG) can represent an alkylene oxide unit (—R—O—) having 1 to 6 carbon atoms as a monomer unit.

Polyalkylene glycols can represent hydrogen end groups, alkyl, aryl, alkylaryl, aryloxy, alkoxy, alkylaryloxy and / or hydroxy end groups. It should be understood that an alkylaryloxy group also means an arylalkyl (ene) oxy group, and an alkylaryl group also means an arylalkyl (ene) group (eg, arylCH ₂ CH ₂ —). The alkyl type end group including the alkoxy type, or the aryl type end group including the alkylaryl type, aryloxy type and alkylaryloxy type is preferably 6 to 24, particularly preferably 6 to 4, based on the aryl type. Represents 18 carbon atoms and preferably represents 1 to 12 carbon atoms based on the alkyl type.

  The polyalkylene glycol of the present invention may be a homogeneous polymer, that is, polypropylene glycol (and / or polypropylene oxide), a copolymer, a terpolymer or the like. In the latter case, the monomer units may represent a random distribution or block structure. If the polyalkylene glycol is not a homogeneous polymer, 20% or more, preferably 40% or more of the total monomer units can be made from polypropylene oxide (PO), and preferably 20% of the total monomer units of these polyalkylene glycols. The above can be produced using ethylene oxide (EO) (PO / EO copolymer). In another embodiment, preferably more than 20%, preferably more than 40% of the total monomer units are obtained from butylene oxide (BO), and preferably more than 20% of the total monomer units of these polyalkylene glycols are ethylene oxide. (BO / EO copolymer).

  When a (poly) alcohol is used, the starting compound is incorporated into the polymer and is also referred to as the end group of the polymer chain in the sense of the present invention. Suitable starting groups are, for example, n-butanol, propylene glycol, ethylene glycol, neopentyl glycol such as pentaerythritol, ethylenediamine, phenol, cresol or other (C1-C16 (mono, di or tri) alkyl) aromatics, It consists of active hydrogen-containing compounds such as (hydroxy) alkyl aromatics, hydroquinone, aminoethanolamine, triethylenetetramine, polyamine, sorbitol or other sugars. Other CH acidic compounds such as carboxylic acids or carboxylic anhydrides can also be used as starting compounds.

  The polyalkylene glycol preferably contains, for example, an aryl group or corresponding heteroaromatic group inserted into the polymer chain as a side group or terminal group. These groups may be substituted with a linear or branched alkyl group or alkylene group, if necessary. Here, the alkyl group or the alkylene group as a whole preferably represents 1 to 18 carbon atoms.

  Cyclic ether alcohols such as hydroxyfurfuryl or hydroxytetrahydrofuran, nitrogen heterocyclic compounds or sulfur-containing heterocyclic compounds can also be used as starting groups. Such polyalkylene glycols are disclosed in WO 01/57164 (the teaching of which is incorporated herein).

The average molecular weight (number average) of the polyalkylene glycol of the present invention is preferably 200 to 3000 g / mol, more preferably 400 to 2000 g / mol. The kinematic viscosity of the polyalkylene glycol is preferably 10 to 400 mm ² / s (cSt) as measured at 40 ° C. according to DIN 51562.

  The polyalkylene glycol used in the present invention can be produced by reacting an alcohol containing a polyalcohol as a starting compound with an oxirane such as ethylene oxide, propylene oxide and / or butylene oxide. After the reaction, the polyalkylene glycol has only one free hydroxy group as a terminal group. Polyalkylene glycols having only one hydroxy group are preferred over those having two free hydroxy groups. For example, polyethylene glycol which no longer contains free hydroxy groups after further etherification is particularly preferred with respect to stability, hygroscopicity and compatibility. Alkylation of the terminal hydroxyl group improves thermal stability. Thus, in a preferred embodiment of the present invention, the PAG base oil comprises a PAG that is end-capped, i.e., free of free hydroxyl groups.

Instead of the aforementioned polyalkylene glycols, esters of neopentyl polyols such as neopentyl glycol, pentaerythritol and trimethylolpropane by addition of linear or branched C _{4 to} C ₁₂ monocarboxylic acids, for example the corresponding dicarboxylic acids Is a suitable neopentyl polyol ester. Pentaerythritol is usually obtained as technical grade pentaerythritol, which is a mixture of monopentaerythritol, dipentaerythritol and tripentaerythritol. However, their condensation products such as dipentaerythritol and / or tripentaerythritol are also suitable as alcohol components.

Particular preference is given to pentaerythritol or a mixture with dipentaerythritol and / or tripentaerythritol, preferably a mixture containing dipentaerythritol as the main component.
Complex esters can be made by proportional esterification of polyhydric alcohols with monohydric acids and dihydric acids such as C _{4 to} C ₁₂ dicarboxylic acids. This method forms dimers and trimers. Complex esters in the case of using neopentyl glycol and / or trimethylolpropane as the alcohol group are preferred.

  There are no particular restrictions on the base oil composition used in the method of the present invention, and various conventional mineral oils and synthetic oils can be conveniently used. For purposes of this description, the term “base oil” is also meant to include a grease base.

It may be advantageous for the base oil composition used in the present invention to contain a mixture of one or more mineral oils and / or one or more synthetic oils.
Mineral oils include liquid petroleum and solvent or acid treated, paraffinic, naphthenic or paraffinic / naphthenic mixed mineral lubricating oils (and may be further refined by hydrofinishing and / or dewaxing). ) Is included.

Suitable base oils for use in the lubricating oil compositions of the present invention are Group I, Group II or Group III base oils, polyalphaolefins, Fischer-Tropsch derived base oils and mixtures thereof.
In the present invention, “Group I” base oil, “Group II” base oil and “Group III” base oil mean lubricating base oils as defined by American Petroleum Institute (API) standards I, II and III. Such API standards are defined in API Publication 1509, 15th edition, Appendix E, April 2002.

  Suitable Fischer-Tropsch derived base oils that can be conveniently used in the lubricating oil composition of the present invention include, for example, EP 0769959, EP 0668342, WO 97/21788, WO 00/15736, WO 00/14188, WO 00/14187, WO 00/14183, WO 00/14179, WO 00/08115, WO 99/41332, EP 1029029, WO 01/18156 and WO 01/57166.

  Synthetic oils include hydrocarbon oils such as olefin oligomers (PAO), dibasic acid esters, polyol esters, and dewaxed waxy raffinates. A synthetic hydrocarbon base oil sold under the name “XHVI” (trade name) by the Shell Group can be conveniently used.

  The total amount of base oil incorporated into the lubricating composition of the present invention is preferably 60-92 wt%, more preferably 75-90 wt%, most preferably 75-88 wt%, based on the total weight of the lubricating composition. It exists in the range of%.

  If desired, the final lubricating composition may further include antioxidants, antiwear agents, dispersants, detergents, friction modifiers, viscosity index improvers, pour point depressants, tackifiers, corrosion inhibitors, demulsifiers, One or more additives such as antifoams and seal fixing or seal matching agents may be included.

  Those skilled in the art are familiar with these and other additives and will not be described further here. These additives may be added to the base oil composition before or after the addition of one or more alkyl-substituted quinolines in step (c). If appropriate, the additive may be added simultaneously with the one or more alkyl-substituted quinolines.

  The additive is usually 0.01 to 12.5% by weight, preferably 0.05 to 10.0% by weight, more preferably 1.0 to 9.0% by weight, based on the total weight of the lubricating composition. Most preferably present in an amount ranging from 2.0 to 5.0% by weight.

  Since the lubricating composition may be in the form of a grease (preferably in the form of a grease), the base oil contained in the lubricating composition may be a metal soap, an organic or inorganic substance such as lithium soap, lithium complex soap, terephthalate One or more thickeners such as sodium acid, urea / urethane compounds and clays may be included or incorporated.

Kinematic viscosity at 100 ° C. of the lubricating composition, preferably in the range of 2~80mm ² / s, more preferably 3~70mm ² / s, most preferably 4~50mm ² / s.

  If the lubricating composition of the present invention is mixed with one or more base oils, and optionally, additives such as those described above that are usually present in lubricating compositions with mineral base oils and / or synthetic base oils, It can be manufactured conveniently. As is customary in the art, the one or more alkyl-substituted quinoline compounds (or oligomeric derivatives thereof) have a sufficiently small particle size (eg, less than 50 μm, preferably less than 20 μm) for easy dispersion in the lubricating composition. Is preferred.

In another aspect, the present invention provides a lubricating composition, particularly a grease, obtained by the method of the present invention.
The invention will now be described with reference to the following examples, which are not intended to limit the scope of the invention in any way.

Solution A of alkyl-substituted quinoline A:
Polyalkylene glycol (from The Dow Chemical Company, USA) before adding 2,2,4-trimethyl-1,2-dihydroquinoline oligomer (solid; obtained from Rhein Chemie Rheinau GmbH under the name "Additin RC7010") “Oxilube 504”) was heated to 100 ° C. to produce 500 ml of 50% m / m polyalkylene glycol solution of 2,2,4-trimethyl-1,2-dihydroquinoline oligomer. 2,2,4-Trimethyl-1,2-dihydroquinoline oligomer was added slowly over about 2 minutes and further dispersed in the liquid prior to addition. The mixture thus obtained was stirred at 100 ° C. for a further 30 minutes. A stable homogeneous solution was formed.

Solution B:
Similar to solution A, 2,2,4-trimethyl-1,2-dihydroquinoline oligomer 50% m / m polyglycol (obtained from The Dow Chemical Company, USA under the trade name “Synalox 50-50B”) 500 ml of solution was produced. A stable homogeneous solution was formed.

Example 1
A grease was prepared using Solution A (50 ml) and a conventional grease substrate (4950 g).
A conventional grease base material has a lithium complex thickener of about 10% m / m, SN 500 and bright stock (viscosity at 40 ° C. according to ASTM D445 = 180 mm ² / g) of about 90 paraffinic mineral base oil. % M / m. Conventional grease substrates also contain an antiwear agent (zinc dialkyldithiophosphate), an extreme pressure additive (sulfurized ester) and a rust inhibitor (zinc naphthenate).

The grease base material and the solution A were preheated to 80 ° C. before mixing, and then mixed for 30 minutes using a laboratory vertical stirrer.
The resulting grease did not show clear defects by visual inspection. No lumps were formed. Also, no separation of 2,2,4-trimethyl-1,2-dihydroquinoline oligomers from the grease occurred after 12 months storage.
Other properties of the resulting grease are shown in Table I below.

  The results in Table I show that the desired properties of the grease, such as mechanical stability, oil retention and surprisingly water stability, are still present in the grease of Example 1, and 2,2,4-trimethyl-1, It shows that it is not influenced by the presence of the solvent (polyalkylene glycol) used to dissolve the 2-dihydroquinoline oligomer.

Example 2
In the same manner as in Example 1, a grease was produced using the solution B.
The resulting grease did not show clear defects by visual inspection. No lumps were formed. Also, after storage for 12 months, separation of 2,2,4-trimethyl-1,2-dihydroquinoline oligomer 2,2,4-trimethyl-1,2-dihydroquinoline from grease did not occur. Similar to Example 1, the grease of Example 2 exhibited the desired properties of mechanical stability, oil retention and water stability.

Comparative Example 1
A grease was prepared using 2,2,4-trimethyl-1,2-dihydroquinoline oligomer (no solvent) and the same grease substrate of Examples 1 and 2.
The grease substrate was heated to about 160 ° C. A portion of this solid 2,2,4-trimethyl-1,2-dihydroquinoline oligomer was then added to the heated grease substrate and left at this temperature for about 10 minutes. Mixing was performed using a laboratory stirrer until the mixture reached a temperature of about 60 ° C.

The mixture was then reheated to about 160 ° C. and left at this temperature for about 30 minutes. Subsequently, the addition and mixing steps were repeated until all 2,2,4-trimethyl-1,2-dihydroquinoline oligomer was added and mixed.
The resulting grease did not show clear defects by visual inspection. No lumps were formed.

Comparative Example 2
A grease was produced in the same manner as Comparative Example 1 except that the heating was about 60 ° C. (instead of about 160 ° C.).
If the solid 2,2,4-trimethyl-1,2-dihydroquinoline oligomer cannot be dispersed in the grease substrate and the grease of Comparative Example 2 is used in, for example, a grease distribution system, severe filter clogging occurs.

Discussion:
As can be seen from the examples, the present invention can provide a deterministic grease that still has the desired properties even when alkyl-substituted quinolines or oligomer derivatives thereof are added at fairly low temperatures. It goes without saying that this is highly desirable from a health and safety standpoint as well as from an actual manufacturing standpoint.
In this connection, it is noted that a stable grease cannot be obtained unless a solvent is used during the addition of the alkyl-substituted quinoline or oligomer derivative thereof (see Comparative Example 2).

International Publication No. 94/24235 US Pat. No. 5,246,606 International Publication No. 01/57164

W. R. Vaughan, “Organic Synthesis”, Collective Volume III, pp 329-30, (1955).

Claims (10)

(A) supplying a base oil composition optionally containing one or more additives,
(B) supplying a solvent solution of one or more alkyl-substituted quinolines or oligomer derivatives thereof; and (c) adding the solution of step (b) to the base oil composition of step (a) at a temperature of less than 150 ° C. The process of
A method for producing a lubricating composition, particularly a grease, comprising at least   The process according to claim 1, wherein in step (c) the solution of step (b) is added at a temperature below 120 ° C, preferably in the range of 10 to 110 ° C, more preferably in the range of 15 to 100 ° C.   The method of claim 1 or 2, wherein the one or more alkyl-substituted quinolines are alkyl-substituted 1,2-dihydroquinolines. The alkyl-substituted 1,2-dihydroquinoline has the general formula (I)

(However, R ^{1 to} R ⁸ are independently selected from hydrogen or an alkyl group having 1 to 8 carbon atoms, and n is 0, 1, 2, or 3)
4. The method of claim 3, comprising: The process according to claim 4, wherein R ^{1 to} R ⁸ are independently selected from hydrogen or an alkyl group having 1 to 4, preferably 1 or 2, carbon atoms. The method according to claim 4 or 5, wherein R ^{4 to} R ⁸ are hydrogen.   The average value of n of the one or more alkyl-substituted 1,2-dihydroquinolines is 1.0 to 2.0, preferably 1.3 to 1.6. the method of.   8. The method of any one of claims 1-7, wherein the solubility of the one or more alkyl-substituted quinolines supplied to the solution is less than 0.1% as measured by ASTM D893.   9. The method according to any one of 1 to 8, wherein the solvent comprises polyglycol, preferably polyalkylene glycol. Lubricating composition obtained by the method according to any one of claims 1 to 9, particularly a grease.