Bio-based lubricants

Abstract

The invention provides biobased lubricants comprising the reaction product of a natural oil, fatty acid or derivative having unsaturation sites with a suitable substrate such as maleic anhydride that is capable of undergoing an “ene” or Diels Alder reaction with the natural oil to form an adduct; followed by a controlled non-aqueous neutralization with a suitable inorganic base such as lithium hydroxide.

Claims

1. Natural oil based lubricants of formulas (i) and (ii) ##STR00007## where R represents the additional carbon and functional moieties associated with a natural oil and where the natural oil or natural oil derivative contains greater than about 80 percent of unsaturated or conjugated unsaturated fatty acids and wherein said lubricant is the reaction product of said natural oil or natural oil derivative with a substrate capable of undergoing a Diels Alder reaction to form an adduct that is further reacted in a neutralization reaction with a lithium base to form an anhydrous gel.

2. The natural oil based lubricants of claim 1, wherein said natural oil is selected from the group consisting of soybean oil, linseed oil, safflower oil, sunflower oil, avocado oil, rapeseed oil, castor oil, tall oil, rosin oil and tung oil.

3. The natural oil based lubricant of claim 1, wherein said substrate is selected from the group consisting of maleic anhydride, itaconic acid, itaconic anhydride, acrylic and methacrylic acid, fumaric acid, aconitic acid, citraconic acid, maleimide and maleamic acid.

4. The natural oil based lubricants of claim 2, wherein said natural oil is soybean oil.

5. The natural oil based lubricants of claim 2, wherein said natural oil is linseed oil.

6. The natural oil based lubricants of claim 2, wherein said natural oil is safflower oil.

7. The natural oil based lubricants of claim 2, wherein said natural oil is avocado oil.

8. The natural oil based lubricants of claim 2, wherein said natural oil is sunflower oil.

9. The natural oil based lubricants of claim 3, wherein said substrate is maleic anhydride.

10. A method for making lubricants based on natural oils and derivatives thereof comprising: (a) reacting the natural oil fatty acid or derivative a suitable substrate that is capable of undergoing a Diels Alder reaction with the natural oil to form an adduct; and (b) subjecting the product of step (a) to a controlled non-aqueous neutralization with a suitable inorganic base.

11. The method of claim 10, wherein said natural oil is selected from the group consisting of soybean oil, linseed oil, safflower oil, sunflower oil, avocado oil, rapeseed oil, castor oil, tall oil, rosin oil and tung oil.

12. The method of claim 11, wherein said natural oil is soybean oil.

13. The method of claim 11, wherein said natural oil is linseed oil.

14. The method of claim 11, wherein said natural oil is safflower oil.

15. The method of claim 11, wherein said natural oil is avocado oil.

16. The method of claim 11, wherein said natural oil is sunflower oil.

17. The method of claim 10 where the substrate is maleic anhydride.

18. The method of claim 10 where the base is lithium hydroxide or lithium carbonate.

19. A natural oil based lubricant obtained by the process of: treating soy bean oil to a form conjugated soil bean oil comprising a conjugated diene; reacting said conjugated diene with an α, β-ethylenically unsaturated dicarboxy compound in a Diels-Alder cycloaddition reaction to form an anhydride ring; and opening said anhydride ring to form a fully or partially neutralized acid salt.

20. A natural oil based lubricant obtained by the process of: treating a natural oil to a form a conjugated natural oil comprising a conjugated diene; reacting said conjugated diene with an α, β-ethylenically unsaturated dicarboxy compound in a Diels-Alder cycloaddition reaction to form an anhydride ring; and opening said anhydride ring to form a fully or partially neutralized acid salt.

21. The natural oil based lubricants of claim 20, wherein said natural oil is selected from the group consisting of soybean oil, linseed oil, safflower oil, sunflower oil, avocado oil, rapeseed oil, castor oil, tall oil, rosin oil, tung oil, linoleic acid, α-linolenic acid, arachidonic acid, icosapentaenoic acid and docosahexaenoic acid.

22. The natural oil based lubricant of claim 20, wherein said α, β-ethylenically unsaturated dicarboxy compound is selected from the group consisting of maleic anhydride, itaconic acid, itaconic anhydride, acrylic and methacrylic acid, fumaric acid, aconitic acid, citraconic acid, maleimide and maleamic acid.

23. The natural oil based lubricants of claim 20 further comprising the reaction product of a second α, β-ethylenically unsaturated dicarboxy compound in an ene reaction.

24. The natural oil based lubricant of claim 23 wherein said second α, β-ethylenically unsaturated dicarboxy compound is selected from the group consisting of maleic anhydride, itaconic acid, itaconic anhydride, acrylic and methacrylic acid, fumaric acid, aconitic acid, citraconic acid, maleimide and maleamic acid.

25. The natural oil based lubricants of claim 20 wherein said acid salt is at least partially neutralized with a salt selected from the group consisting of lithium hydroxide and lithium carbonate.

26. A method for making natural oil based lubricants comprising: forming a conjugated natural oil from a natural oil wherein said conjugated natural oil comprises a conjugated diene having a structure
R.sup.1—CH═CH—CH═CH—R.sup.2 wherein said R.sup.1 and R.sup.2 represent the additional moieties associated with said conjugated natural oil; reacting said conjugated diene with an α, β-ethylenically unsaturated dicarboxy compound to form a maleated natural oil comprising an anhydride ring having a structure: ##STR00008## and opening said anhydride ring.

27. The method for making natural oil based lubricants of claim 26 wherein said opening of said anhydride ring comprises forming a full or partially neutralized acid salt.

28. The method for making natural oil based lubricants of claim 26 wherein said forming of said conjugated natural oil from said natural oil comprises reacting said natural oil with a double bond isomerization catalyst.

29. The method for making natural oil based lubricants of claim 28 wherein said double bond isomerization catalyst is iodine.

30. The method for making natural oil based lubricants of claim 26 wherein said forming of said conjugated natural oil from said natural oil comprises reaction of said natural oil with a second α, β-ethylenically unsaturated dicarboxy compound in an Alder-ene addition.

31. The method for making natural oil based lubricants of claim 30 wherein said second α, β-ethylenically unsaturated dicarboxy compound is selected from the group consisting of maleic anhydride, itaconic acid, itaconic anhydride, acrylic and methacrylic acid, fumaric acid, aconitic acid, citraconic acid, maleimide and maleamic acid.

32. The method for making natural oil based lubricants of claim 26 wherein said opened anhydride ring is at least partially neutralized with a salt selected from the group consisting of lithium hydroxide and lithium carbonate.

33. The method for making natural oil based lubricants of claim 26 wherein said maleated natural oil comprising an anhydride ring has a structure: ##STR00009##

34. The method for making natural oil based lubricants of claim 33 wherein said maleated natural oil comprising an anhydride ring has a structure: ##STR00010## wherein R.sup.3 is R.sup.1 less an alkene.

Description

EXAMPLES

(1) The following examples are intended to demonstrate the usefulness of preferred embodiments of the present invention and should not be considered to limit its scope or applicability in any way.

Examples 1-11

(2) The following method was used to prepare the natural oil based lubricants in Table 1. In a first step, 2000 g of the natural oil and the desired amount (as shown in the table) of maleic anhydride were charged to a 3 L four-neck round-bottom flask. The contents of the flask were gradually heated to 210° C. with agitation under a nitrogen sparge. The reaction mixture was held at this temperature until no free maleic anhydride was detected in the reaction mixture by GC analysis. The reaction mixture was cooled to 50° C. and the desired amount of solid Lithium Hydroxide was added. The reaction mixture was heated at 125-140° C. until the reaction mixture had cleared. Vacuum may be applied to remove excess water but is not necessary. The lubricants obtained had exemplary properties being clear and transparent and exhibited no oil bleed or undissolved saponified triglyceride.

(3) TABLE-US-00001 TABLE 1 Properties of Maleated Triglyceride Oils/Lithium Hydroxide Neutralized Percent Maleic Example Anhydride Clarity Oil Bleed Viscosity (cP) 1) Soybean Oil.sup.a 7.5 Transparent None  1200 2) Soybean Oil.sup.a 10 Transparent None 40000 3) Soybean Oil.sup.a 12 Transparent None Soft Gel (Tacky) 4) Soybean Oil.sup.b 14 Transparent None Hard Gel (no Tack) 5) Linseed Oil.sup.a 10 Transparent None 80000 6) Linseed Oil.sup.a 12 Transparent None Soft Gel (Tacky) 7) Linseed Oil.sup.b 14 Transparent None Hard Gel (no Tack) 8) Safflower Oil.sup.a 10 Transparent None 70000 9) Safflower Oil.sup.b 14 Transparent None Hard Gel (no Tack) 10) Avacodo Oil 12 Transparent None Soft Gel (Tacky) 11) Sunflower 14 Transparent None Hard Gel Oil.sup.b (no Tack) .sup.a(0.25 eq:1.0 eq. Maleic Anhydride) .sup.b(0.5 eq:1.0 eq. Maleic Anhydride)

(4) All patents, patent applications and publications cited in this application including all cited references in those patents, applications and publications, are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual patent, patent application or publication were so individually denoted.

(5) While the many embodiments of the invention have been disclosed above and include presently preferred embodiments, many other embodiments and variations are possible within the scope of the present disclosure and in the appended claims that follow. Accordingly, the details of the preferred embodiments and examples provided are not to be construed as limiting. It is to be understood that the terms used herein are merely descriptive rather than limiting and that various changes, numerous equivalents may be made without departing from the spirit or scope of the claimed invention.