Tall oil derivative replacements

Abstract

Blends containing a homogeneous mixture of i) vegetable oil fatty acids from annual crop plants and ii) rosin acid are provided for use in metal cutting fluids and in other products employing tall oil derivatives. The blends may be combined with an emulsifying agent and water under high shear conditions to form metal cutting fluid emulsions, may be used as lubricity additives to improve the performance of non-emulsified metal cutting fluids, and may be used in other products including oilfield additives, detergents, soaps, surfactants, mining fluids, and resins.

Description

TALL OIL DERIVATIVE REPLACEMENTSCross-Reference to Related Application

[0001] This application claims priority from U.S. Provisional Application Serial No. 63 / 562,586 filed March 7, 2024 and entitled “METAL CUTTING FLUIDS”, the disclosure of which is incorporated herein by reference.Technical Field

[0002] This invention relates to replacements for tall oil derivatives.Background

[0003] Tall oil derivatives have a number of valuable uses. However, due to increased consumption of crude tall oil (CTO) by the biofuels market, there is decreased CTO availability and increased CTO pricing for other end uses. Similar availability and pricing pressures apply to fractionated products derived from CTO, such as Tall Oil Fatty Acid (TOFA) and distilled tall oil (DTO).

[0004] Metalworking operations frequently employ specialized lubricants to assist in drilling, punching, sawing and other operations involving the cutting of metals. These lubricants are typically referred to as “cutting fluids”, are normally in the form of emulsions, and may be required to meet several industry-standard tests. TOFA and DTO are widely used as emulsifiers and lubricity additives in metal cutting fluids. Both TOFA and DTO contain appreciable quantities of rosin acids. According to metalworking lubricant industry experts, the rosin acids in TOFA and DTO can provide improved lubricity, increased emulsion stability, reduced foaming, and increased microbial resistance in a metal cutting fluid. However, the rosin acid composition of TOFA and DTO can be inconsistent, and this inconsistency may be aggravated when the above- mentioned availability or pricing pressures lead a purchaser to change TOFA or DTO suppliers, or when the supplier changes its own upstream sources. The degree of rosin acid inconsistency may be further appreciated by reviewing the composition ranges shown below in Table 1 for typical TOFA and DTO samples:Table 1Composition TOFA DTO% Fatty Acids 93 - 99.5 % 68 - 75 %% Rosin Acids 0.5 - 5 % 25 - 30 %% Unsaponifiable Matter 0 - 2 % 0 - 2 %Total 100 % 100 %

[0005] As the ratio of fatty acids to rosin acids shifts, cutting fluid formulators must adjust their emulsion or other lubricating fluid formulations and processes to compensate. This can require extra testing, time and expense, and even so may still result in undesirable variation in cutting fluid product quality.Summary

[0006] Better or more consistent replacements for TOFA and DTO would be appreciated within the art. In addition, it would be desirable if such replacements could be biorenewable materials. The present disclosure addresses that need.

[0007] Blends comprising a homogeneous mixture of i) vegetable oil fatty acids from annual crop plants and ii) rosin acid are provided for use as tall oil derivative replacements. The blends may be combined with an emulsifying agent and water under high shear conditions to form metal cutting fluid emulsions, and may also be used as lubricity additives to improve the performance of non-emulsified metal cutting fluids. The disclosed blends also may be used in other products that have employed tall oil derivatives, for example oilfield additives, detergents, soaps, surfactants, mining fluids and resins.

[0008] In some embodiments the blends are heated at an elevated temperature and for a time sufficient to remove or reduce crystallinity such as may be manifested by haziness and light scattering within the blend.

[0009] In some embodiments the disclosed blends are employed in metal cutting fluid emulsions, oilfield additives, detergents, soaps, surfactants, mining fluids or resins comprising an oil phase containing the above-mentioned blends dispersed in an aqueous phase. In other embodiments the disclosed blends are employed in metal cutting fluids,oilfield additives, detergents, soaps, surfactants, mining fluids, or resins comprising a homogenous mixture (e.g., a non-emulsified mixture) of the above-mentioned blends.

[0010] Methods for preparing fluid emulsions are also provided, comprising the steps of combining a homogeneous mixture of i) vegetable oil fatty acids from annual crop plants and ii) rosin acid with water and optionally with another emulsifying agent under high shear conditions to form an emulsion.

[0011] In some embodiments, and unlike TOFA and DTO, the chosen vegetable oil fatty acids typically will not contain rosin acids, which are obtained from trees rather than from annual crop plants. The rosin acid content of the disclosed blends consequently can easily be selected prior to blending, to provide blends whose performance (e.g., in a metal cutting fluid) is more predictable than currently will be obtained using commercially- supplied TOFA or DTO, and while minimizing or eliminating sample-to- sample rosin acid concentration and performance variation. The disclosed blends are derived from readily biorenewable and abundant sources.Brief Description of the Drawing

[0012] In the accompanying Drawing, Fig. l is a graph showing thread cutting torque measurements using several cutting fluids and 6061 aluminum alloy, and

[0013] Fig. 2 is a graph showing thread cutting torque measurements using several cutting fluids and 1018 steel alloy.Detailed Description

[0014] The present specification provides certain definitions and methods to better define the present invention and to guide those of ordinary skill in the art in the practice of the present invention. Provision, or lack of the provision, of a definition for a particular term or phrase is not meant to bely any particular importance, or lack thereof. Rather, and unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art.

[0015] The terms “a” and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0016] The term “about” refers to a range of numbers that may be considered equivalent to a recited value (e.g., having the same function or result), and includes values rounded to the nearest significant figure.

[0017] The terms “first”, “second”, and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[0018] Where ranges are disclosed, the endpoints of all ranges directed to the same component or property are inclusive and independently combinable (e.g., ranges of “up to about 25 wt. %, or, more specifically, about 5 wt. % to about 20 wt. %,” are inclusive of the endpoints and all intermediate values of the ranges of “about 5 wt. % to about 25 wt. %,” etc.). Further, ranges are inclusive of all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4 and 5).

[0019] All parts and percentages are by weight unless otherwise stated.

[0020] Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0021] The term “vegetable oil fatty acids from annual crop plants” refers to fatty acids obtained from plants having a one-year life cycle, and includes both annual and perennial plants but does not include trees.

[0022] The disclosed blends may comprise, consist essentially of, or consist of vegetable oil fatty acid(s) and rosin acid(s). A variety of vegetable oil fatty acids may be used in the disclosed blends. Exemplary vegetable oil fatty acids include, but are not limited to, those found in soybean oil, linseed oil, canola oil, rapeseed oil, cottonseed oil, sunflower oil, palm oil, peanut oil, safflower oil, com oil, com stillage oil, castor oil, any other suitable vegetable oil, and combinations thereof. The fatty acid content in such oils may be increased by de-esterifying the triglycerides that may be present in such oils (e.g., using enzymatic cleavage) to produce fatty acids and glycerine. The vegetable oil fatty acids may also be refined or otherwise further processed to remove excess quantities of gums (e.g., phospholipids), triglycerides, volatile components and other materials that maybe unneeded in or detrimental for the intended use (e.g., for metal cutting fluid use). The disclosed blends may for example contain at least about 65 wt. %, at least about 70 wt. %, at least about 75 wt. % or at least about 80 wt. %, and up to about 99 wt. %, up to about 98 wt. %, up to about 97 wt. %, up to about 96 wt. %, up to about 95 wt. %, up to about 92 wt. % or up to about 90 wt. % vegetable oil fatty acids based on the total weight of the blend.

[0023] Suitable vegetable oil fatty acids are available from a variety of suppliers including Bunge, Cargill Incorporated, Dow Inc., Eastman Chemical Company, Oleon N.V. and Trucent Renewable Chemicals. For example, exemplary products from Trucent include TRUFA™ OA-3080, TRUFA OA-3175, TRUFA OA-3075, TRUFA OA-3060 and TRUFA OA-3100(NK) vegetable oleic acids; TRUFA FA-2100, TRUFA FA-2003, TRUFA FA-2005 and TRUFA FA-2331 soy fatty acids; TRUFA FA-5000 linseed fatty acid; TRUFA FF-1331, TRUFA FF-4005 and TRUFA FF-4009 vegetable fatty acid blends.

[0024] A variety of rosin acids may be used in the disclosed blends. Rosin acids typically are obtained from coniferous trees, examples of which include Pinus kesiya Royle (Khasi Pine), Pinus insularis (Benguet pine), Pinus sylvestris (Scotch Pine) and Pinus strobus (Eastern White Pine). Exemplary rosin acids include, but are not limited to, those obtained from wood rosin (e.g., by extraction of rosin acids from the aged heartwood of pine sumps) and gum rosin (e.g., by extraction of rosin acids from pine gum). Tall oil rosin acids (e.g., rosin acids obtained by crystallization of DTO to separate rosin acids from fatty acids). Due to the purification processes by which they are made, tall oil rosin acids exhibit relatively less sample-to-sample variability in rosin acid content than is the case for TOFA and CTO, but they may to some extent be subject to the above-mentioned availability and pricing concerns if CTO supplies are constrained. Exemplary wood rosin acids and their suppliers include PEXITE™ WW and PEXITE FF wood rosin from Pinova, Inc. Exemplary gum rosin acids and their suppliers can be found in many countries including Brazil, China, Indonesia, Venezuela and the US. Exemplary tall oil rosin acid suppliers include Ingevity and Kraton. Combinations of rosin acids may also be employed. The disclosed blends may for example contain at least about 1 wt. %, at least about 2 wt. %, at least about 3 wt. %, about 4 wt. %, at least about 5 wt. %, at least about 8wt. % or at least about 10 wt. %, and up to about 35 wt. %, up to about 30 wt. %, up to about 25 wt. % or up to about 20 wt. % rosin acids based on the total weight of the blend.

[0025] If desired, TOFA or CTO could also be added to the disclosed blends, subject however to the rosin acid content variability in TOFA and CTO mentioned above.

[0026] The disclosed blends may be translucent, homogenous and free of visibly discernible undissolved or crystalline species, or may include crystalline species. Homogeneity may be improved by heating the blend at an elevated temperature and for a time sufficient to remove or reduce crystallinity such as may be manifested by haziness and light scattering within the blend, and believed to be caused by the presence of crystalline rosin acid species. Exemplary heating times and temperature include heating the blend to 150 - 270°C and mixing for 1 - 4 hours. Blends may be formed using conventional mixing equipment, such as paddle stirrers, LIGHTNIN™ mixers, or homogenizers such as the COWLES™ dissolver that may be used for subsequent emulsion formation.

[0027] The disclosed blends may include a variety of adjuvants. Exemplary such adjuvants include additional emulsifiers. pH control agents, foam control agents, coupling agents, anti-wear additives, corrosion inhibitors, staining inhibitors, biocides, colorants and indicators.

[0028] The disclosed blend may for example have an acid number (a measure of acid content) of at least 150, at least 160, at least 170 or at least 180, and up to about 230, up to about 220, up to about 210 or up to about 200 mg KOH / g. The disclosed blends many have an iodine value (a measure of unsaturation) of at least about 100, at least about 110 or at least about 120, and up to about 200, up to about 180 or up to about 160 grams I2 / IOO g oil. By selecting a desired rosin acid content in the disclosed blends, these and other properties of interest may be adjusted as need be. For example, the blend may be adjusted to exhibit properties falling within one or more of the ranges shown below in Table 2:Table 2Property Test ValueAcid Number, mg KOH / g 184 - 194Iodine Value 122 - 152Color, Gardner 4 - 8Titer Point, °C 10 - 19% Rosin Acids 0.5 - 30

[0029] In some embodiments, the disclosed blends exhibit one or more and preferably each of the properties shown below in Table 3:Table 3Property Test ValueAcid Number, mg KOH / g 187 - 194Iodine Value 125 - 150Color, Gardner 5 - 7Titer Point, °C 6 - 8

[0030] The disclosed blends may be formed into emulsions using techniques like those employed when using TOFA or CTO, and which consequently will be familiar to persons having ordinary skill in the art. Typically, the blend will be added to water and subjected to suitably high mixing energy (using for example a Cowles Dissolver or other appropriate mixing device) to form a storage-stable, uniform emulsion. The disclosed blends may also be used as additives in non-emulsified fluids (e.g., in non-emulsified cutting fluids), using techniques like those employed when using TOFA or CTO, and which will likewise be familiar to persons having ordinary skill in the art.

[0031] Emulsions and non-emulsified cutting fluids made using from the disclosed blends may be subjected to a variety of tests. Representative tests include but are not limited to those shown below in Table 5. For each such test, the latest approved version of the standard as of the present application filing date should be employed:Table 5

[0032] The invention is further illustrated in the following non-limiting examples.Examples 1-4

[0033] Four blend formulations containing varying amounts of TRUFA FA-4005 vegetable oil fatty acid from Trucent and SYLVAROS GRS rosin acid from Kraton were prepared. TRUFA FF-4005 is a mixed fatty acid product manufactured by enzymatic cleavage of the triglycerides found in soybean oil to produce fatty acids and glycerine. Itstypical composition is 7% palmitic acid, 3% stearic acid, 44% oleic acid, 40% linoleic acid, and 6% linolenic acid. SYLVAROS GRS is a mid-grade, tall oil rosin acid. The blends were formed by mixing and heating the ingredients at the top mixing temperature and mixing time indicated below, to yield blends having the properties shown below in Table 6:Table 6Blend Ex. 1 Ex. 2 Ex. 3 Ex. 4TRUFA FF-4005 96.5 % 94.2 % 71.0 % 65.2 %SYLVAROS GRS 3.5 % 5.8 % 29.0 % 34.8 %Total 100.0 % 100.0 % 100.0 % 100.0 %Top Mixing Temp., °C 150°C 150°C 150°C 150°CMixing Time, hours 1 hr 1 hr 1 hr 1 hrAnalytical Properties% Rosin Acids 3.0 5.0 25.0 30.0Acid Number, mg KOH / g 194 192 186 184Iodine Value 122 125 135 138Color, Gardner 4+ 5 7 8Titer Point, °C 19 18 10 12Viscosity @ 25 °C, cP 34.5 36.7 98.3 140Specific Gravity 0.9 0.92 0.94 0.95

[0034] These blends form milky-white cutting fluid emulsions that may be used as drop-in replacements for products (e.g., cutting fluids) made from TOFA or CTO.Examples 5-8 Rosin Source

[0035] In order to evaluate the effect of different rosin sources, four vegetable oil / rosin acid blends were prepared using two tall oil rosin samples and two gum rosin samples using the amounts and having the properties shown below in Table 7:Table 7Blend Ex. 5 Ex. 6 Ex. 7 Ex. 8TRUFA FF-4005 98.5 % 98.5 % 97 % 97 %Tall Oil Rosin A 1.5 %Gum Rosin A 1.5 %Tall Oil Rosin B 3 %Gum Rosin B 3 %Total 100.0 % 100.0 % 100.0 % 100.0 %Acid Number, mg KOH / g 198 201 195 196Viscosity at 25°C, cP 28 29 31 31Gardner Color 4 4 6 4

[0036] The blends were stored for four weeks under a variety of storage conditions viz., at an ambient temperature of 21°C. in a freezer at -5°C, in a refrigerator at 3°C, and in an oven at 60°C) and were observed to remain homogenous and unchanged in appearance under each of these storage conditions.

[0037] The blends were also evaluated in three exemplary cutting fluid emulsions, namely two (Formulation A and Formulation B) for use on aluminum and a third formulation for use on steel. The formulations were also compared to a standard cutting fluid emulsion based on SYLFAT FA-2 TOFA. Overall, the formulations based on the Example 5-8 blends exhibited at most 0.5% more foaming or creaming than the standard cutting fluid emulsion. This did not adversely affect metal cutting performance or performance of the exemplary cutting fluid emulsions in tests like those in Table5. Measurements of thread cutting torque on 6061 aluminum alloy for Formulation A and Formulation B are shown in Fig. 1, and measurements of thread cutting torque on 1018 steel alloy for the third formulation are shown in Fig. 2. The results were comparable to those obtained using the standard cutting fluid emulsion based on SYLFAT FA-2 TOFA.

[0038] The above description is directed to the disclosed blends and methods and is not intended to limit them. Those of skill in the art will readily appreciate that the teachings found herein may be applied to yet other embodiments within the scope of the attached claims. The complete disclosures of all cited patents, patent documents, and publicationsare incorporated herein by reference as if individually incorporated. However, in case of any inconsistencies the present disclosure, including any definitions herein, will prevail.

Claims

Claims:

1. Blends comprising a homogeneous mixture of i) vegetable oil fatty acids from annual crop plants and ii) rosin acid.

2. A blend according to claim 1, wherein the blend comprises one or more vegetable oil fatty acids from soybean oil, linseed oil, canola oil, rapeseed oil, cottonseed oil, sunflower oil, palm oil, peanut oil, safflower oil, corn oil, com stillage oil, castor oil, and combinations thereof.

3. A blend according to claim 1, wherein the vegetable oil fatty acid is from soybean oil.

4. A blend according to claim 1, wherein the vegetable oil fatty acid is from linseed oil.

5. A blend according to any one of the preceding claims, wherein the vegetable oil fatty acid is from canola oil, rapeseed oil, cottonseed oil, sunflower oil, palm oil, peanut oil, safflower oil, corn oil, corn stillage oil or castor oil.

6. A blend according to any one of the preceding claims, wherein the rosin acid comprises wood rosin.

7. A blend according to any one of the preceding claims, wherein the rosin acid comprises gum rosin acid.

8. A blend according to any one of the preceding claims, wherein the rosin acid comprises wood rosin acid.

9. A blend according to any one of the preceding claims, wherein the rosin acid comprises tall oil rosin acid.

10. A blend according to any one of the preceding claims, comprising at least about 65 wt. %, at least about 70 wt. %, at least about 75 wt. % or at least about 80 wt. vegetable oil fatty acids based on the total weight of the blend.

11. A blend according to any one of the preceding claims, comprising up to about 99 wt. %, up to about 98 wt. %, up to about 97 wt. %, up to about 96 wt. %, up to about 95 wt. %, up to about 92 wt. % or up to about 90 wt. % vegetable oil fatty acids based on the total weight of the blend.

12. A blend according to any one of the preceding claims, comprising at least about 1 wt. %, at least about 2 wt. %, at least about 3 wt. %, about 4 wt. %, at least about 5 wt. %, at least about 8 wt. % or at least about 10 wt. %, rosin acids based on the total weight of the blend.

13. A blend according to any one of the preceding claims, comprising up to about 35 wt. %, up to about 30 wt. %, up to about 25 wt. % or up to about 20 wt. % rosin acids based on the total weight of the blend.

14. A blend according to any one of the preceding claims, wherein the blend has been heated at an elevated temperature and for a time sufficient to remove or reduce crystallinity such as may be manifested by haziness and light scattering within the blend.

15. A blend according to any one of the preceding claims, wherein the blend has been heated to 150 - 270°C and mixed for 1 - 4 hours.

16. A blend according to any one of the preceding claims, wherein the blend is translucent, homogenous and free of visibly discernible undissolved or crystalline species.

17. A blend according to any one of the preceding claims, consisting essentially of vegetable oil fatty acid(s) and rosin acid(s).

18. A metal cutting fluid emulsion comprising an oil phase containing a blend according to any one of the preceding claims dispersed in an aqueous phase.

19. Metal cutting fluids comprising a blend according to any one of claims 1 to 18.

20. An oilfield additive comprising a blend according to any one of claims 1 to 18.

21. A detergent, soap or surfactant comprising a blend according to any one of claims1 to 18.

22. A mining fluid comprising a blend according to any one of claims 1 to 18.

23. A resin comprising a blend according to any one of claims 1 to 18.

24. Methods for preparing an emulsion, comprising the steps of combining a homogeneous mixture of i) vegetable oil fatty acids from annual crop plants and ii) rosin acids with water and optionally with another emulsifying agent under high shear conditions to form the emulsion.

25. A method according to claim 24, wherein the blend comprises one or more vegetable oil fatty acids from soybean oil, linseed oil, canola oil, rapeseed oil, cottonseed oil, sunflower oil, palm oil, peanut oil, safflower oil, corn oil, corn stillage oil, castor oil, and combinations thereof.

26. A method according to claim 24, wherein the vegetable oil fatty acid is from soybean oil.

27. A method according to claim 24, wherein the vegetable oil fatty acid is from linseed oil.

28. A method according to any one of claims 24 to 27, wherein the vegetable oil fatty acid is from canola oil, rapeseed oil, cottonseed oil, sunflower oil, palm oil, peanut oil, safflower oil, corn oil, corn stillage oil or castor oil.

29. A method according to any one of claims 24 to 28, wherein the rosin acid comprises wood rosin.

30. A method according to any one of claims 24 to 29, wherein the rosin acid comprises gum rosin acid.

31. A method according to any one of claims 24 to 30, wherein the rosin acid comprises wood rosin acid.

32. A method according to any one of claims 24 to 31, wherein the rosin acid comprises tall oil rosin acid.

33. A method according to any one of claims 24 to 32, wherein the blend comprises at least about 65 wt. %, at least about 70 wt. %, at least about 75 wt. % or at least about 80 wt. vegetable oil fatty acids based on the total weight of the blend.

34. A method according to any one of claims 24 to 33, wherein the blend comprises up to about 99 wt. %, up to about 98 wt. %, up to about 97 wt. %, up to about 96 wt. %, up to about 95 wt. %, up to about 92 wt. % or up to about 90 wt. % vegetable oil fatty acids based on the total weight of the blend.

35. A method according to any one of claims 24 to 34, wherein the blend comprises at least about 1 wt. %, at least about 2 wt. %, at least about 3 wt. %, about 4 wt. %, at least about 5 wt. %, at least about 8 wt. % or at least about 10 wt. %, rosin acids based on the total weight of the blend.

36. A method according to any one of claims 24 to 35, wherein the blend comprises up to about 35 wt. %, up to about 30 wt. %, up to about 25 wt. % or up to about 20 wt. % rosin acids based on the total weight of the blend.

37. A method according to any one of claims 24 to 36, further comprising heating the blend at an elevated temperature and for a time sufficient to remove or reduce crystallinity such as may be manifested by haziness and light scattering within the blend.

38. A method according to any one of claims 24 to 37, wherein the blend has been heated to 150 - 270°C and mixed for 1 - 4 hours.

39. A method according to any one of claims 24 to 38, wherein the blend is translucent, homogenous and free of visibly discernible undissolved or crystalline species.

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