Metalworking fluid containing a branched alcohol propoxylate

Abstract

The present invention relates to a method of processing a workpiece comprising contacting a tool and a workpiece to effect a change in the shape of the workpiece, and applying a metalworking fluid to a surface area where the tool and the workpiece are in contact, where the metalworking fluid contains a propoxylate of the formula R—O—(C.sub.3H.sub.6O).sub.n—H, where R is a branched C.sub.6 to C.sub.20 alkyl and n is from 3 to 30. The invention further relates to the metalworking fluid, and to a use of the propoxylate as additive in metalworking fluids.

Claims

1. A method of processing a workpiece comprising a) contacting a tool and a workpiece to effect a change in the shape of the workpiece, and b) applying a metalworking fluid to a surface area where the tool and the workpiece are in contact, where the metalworking fluid contains a propoxylate of the formula R—O—(CH.sub.2—CH(CH.sub.3)—O).sub.n—H, where R is a branched C.sub.10 to C.sub.13 alkyl and n is from 5 to 25, and wherein the metalworking fluid is formulated as a straight oil, which contains the at least 80 wt % of a propoxylate, and which is applied without dilution of water; a soluble oil, which contains 30 to 85 wt % mineral oil and up to 20 wt % propoxylate, and which is applied after dilution with water as aqueous emulsion; or a semi-synthetic fluid, which contains 5-30 wt % mineral oil, 30-50 wt % water, and up to 20 wt % propoxylate, and which is applied without dilution of water.

2. The method according to claim 1 where R is a branched C.sub.13 alkyl.

3. The method according to claim 1 where R is a tridecanol mixture, which comprises singly, doubly and triply branched tridecanols.

4. The method according to claim 3 where the tridecanol mixture comprises 20 to 60% of at least triply branched tridecanols, 10 to 50% doubly branched tridecanols, and 5 to 30% singly branched and/or linear tridecanols, and where the percentages are determined by gas chromatography.

5. The method according to claim 1 where the metalworking fluid is formulated as straight oil which contains at least 90 wt % propoxylate and optionally an antioxidant.

6. The method according to claim 1 where the metalworking fluid is formulated as soluble oil which contains 30 to 85 wt % mineral oil, up to 30 wt % water, and up to 10 wt % propoxylate.

7. The method according to claim 1 where the metalworking fluid is applied in a quantity of 5 to 50 ml/h.

8. The method according to claim 1 where the workpiece is made of pure metals or metal alloys.

9. A metalworking fluid as defined in claim 1.

10. A method comprising utilizing the propoxylate as defined in claim 1 as additive in metalworking fluids.

11. The method according to claim 1, wherein R is branched C.sub.13 alkyl or branched C.sub.10 alkyl.

12. The method according to claim 1, wherein R is 2-propyl-heptyl.

Description

EXAMPLES

Example 1—Tridecanol Mixture

(1) A technical mixture of tridecanol was prepared as described in US 2003/0187114 starting from a technical C.sub.4-raffinate. A technical mixture of butane and butenes isomers was subjected to dimerization on a heterogeneous catalyst to produce a mixture of octene isomers and dodecene isomers. The dodecene isomers were separated by distillation. The isomeric dodecenes were hydroformylated with synthesis gas comprising hydrogen and carbon monooxide, and subsequently hydrogenated with hydrogen. The resulting tridecanol mixture was isolated by fractional distillation.

(2) The density of the tridecanol mixture was 0.843 g/cm.sup.3, the refractive index n.sub.D.sup.20 was 1.448, the viscosity was 34.8 mPas, and the boiling range was from 251 to 267° C. (according to DIN 51751).

(3) The fraction of the tridecanol isomers was at least 99.0% by area as determined by gas chromatography according to DIN 55685. The content of dodecanol and of tetradecanol was each below 1% by area as determined by gas chromatography.

(4) The tridecanol mixture was analyzed by gas chromatography as described in US 2003/0187114 using the Kovacs method: A specimen of the isotridecanol was trimethylsilylated using 1 ml of N-methyl-N-trimethylsilyltrifluoroacetamide per 100 μl of specimen for 60 minutes at 80° C. For separation by gas chromatography use was made of a Hewlett Packard Ultra 1 separating column of 50 m in length, based on 100%-methylated silicone rubber, with an internal diameter of 0.32 mm. Injector temperature and detector temperature were 250° C. and the oven temperature was 160° C. (isothermal). The split was 80 ml/min. The carrier gas was nitrogen. The inlet pressure was set to 2 bar. 1 μl of the specimen was injected into the gas chromatograph, and the separated constituents were detected by means of FID.

(5) The reference substances used here were n-undecanol: Retention index (“RI”) 1100; n-dodecanol: Retention index 1200; and n-tridecanol Retention index 1300. For evaluation purposes the gas chromatogram was subdivided into the following regions:

(6) Region 1: Retention index less than 1180

(7) Region 2: Retention index from 1180 to 1217

(8) Region 3: Retention index greater than 1217

(9) The areas of the tridecanol peaks were set to 100 percent by area. The results are summarized in Table A.

(10) TABLE-US-00001 TABLE A Retention index Branching Tridecanol Mixture less than 1180 at least triply branched 46% 1180 to 1217 doubly branched 35% greater than 1217 singly branched and/or linear 19%

Example 2—Propoxylates

(11) Propoxylate A

(12) In a 2 L-autoclave a double metal cyanide (DMC) catalyst (23 mg, prepared according to WO 2003/066706, page 13-14) was suspended in the Tridecanol Mixture (170.3 g). The reactor was closed and three vacuum purge cycles were applied. The mixture was then heated to 135° C. At this temperature propylene oxide (740.5 g) was added steadily over a period of 6.25 h. Afterwards the mixture was stirred for another 5 h at the same temperature and finally cooled down to room temperature. The product (900 g) was obtained as a light yellow oil.

(13) Propoxylate A was obtained having on average 15 propylene oxide units, acid value 0.24 (DGF C-V 2), pour point −51° C. (DIN ISO 3016), kinematic viscosity at 40° C. of 56 mm.sup.2/s, kinematic viscosity at 100° C. of 10 mm.sup.2/s (ASTM D 445).

(14) Propoxylate B

(15) A solution of KOH (8 g) in water (8 g) was added to the Tridecanol Mixture (1200 g) and stirred in a round-bottom flask for 2 h at 100° C. under vacuum. Afterwards the mixture was filled into an autoclave and heated to 130° C. Propylene oxide (2788 g) was then added over a period of 66 h, the mixture was stirred for an additional 6 h and cooled to 100° C. A magnesium silicate absorber (120 g) was added, the mixture was stirred for 2 h at 100° C. and then filtered. The product (3980 g) was obtained as a light yellow oil.

(16) Propoxylate B was obtained having on average 8 propylene oxide units, acid value 0.1, pour point −54° C., kinematic viscosity at 40° C. of 29 mm.sup.2/s, kinematic viscosity at 100° C. of 6 mm.sup.2/s.

(17) Propoxylate C

(18) The Propoxylate C was prepared according to Propoxylate A and B based on a 2-propylheptanol. Propoxylate C was obtained having on average 8 propylene oxide units

Example 3—Application Tests

(19) The application test were made as describe below and the results summarized in Table 1. For comparison a commercially available Synative® AL G 16 (a 2-hexyldecan-1-ol guerbet alcohol) was used (pour point −60° C., kinematic viscosity at 40° C. of 19 mm.sup.2/s, kinematic viscosity at 100° C. of 2.8 mm.sup.2/s). The following test methods were used: Reichert Wear Scar tested as 20 wt % in Nynas® T22 (mid viscosity hydrotreated naphthenic oil for metalworking fluids, KV40 about 22 cSt). The Reichert wear tester consists of two cylinders made of stainless steel (V2A). One is used as the stationary wear member and the second cylinder as the rotating wear member that operates at 90 degrees to the stationary member. The fluid reservoir is filled with a 1 percent solution of the test-substance in water. After 100 m the rotation is stopped, metal-cylinders are washed with ethanol and the wear-scar of the stationary wear member is analysed (measured in mm.sup.2). KV40 (20 wt % in oil): kinematic viscosity at 40° C. of a 20 wt % solution in Nynas® T22. KV100 (20 wt % in oil): kinematic viscosity at 100° C. of a 20 wt % solution in Nynas® T22.

(20) The results showed improvements with regard to a reduced wear scar and an increased VI.

(21) TABLE-US-00002 TABLE 1 Synative ® AL G16 Propoxylate A Propoxylate B Propoxylate C (comparative) Reichert Wear Scar  26 mm.sup.2 30 mm.sup.2  29 mm.sup.2  35 mm.sup.2 KV40 (20 wt % in oil)  26 mm.sup.2/s 22 mm.sup.2/s  21 mm.sup.2/s  18 mm.sup.2/s KV100 (20 wt % in oil) 4.5 mm.sup.2/s  4 mm.sup.2/s 3.8 mm.sup.2/s 3.1 mm.sup.2/s Viscosity Index 76 48 45 42

Example 4—Formulation Stability

(22) A typical metalworking fluid formulation was prepared comprising the following commercially available components listed in Table 2. In addition the formulations contained 1.5% of Propoxylate A, B or the comparative Synative® AL G16.

(23) TABLE-US-00003 TABLE 2 Component Amount [%] Monoethanol Amine 9.1 Triethanolamine 2 Irgacor ® L190Plus 4.1 Deionized water 10.3 Tall Oil Fatty Acid (25/30) 5.2 Ricinoleic acid 7 complex ester based on fatty acids 2.2 Synative ® AC 3499 1 Synative ® AC 3370 V 3 Synative ® EP 5 LV 5.6 NYNAS ® T 22 49

(24) The stability of this metalworking fluid formulation was tested by storing the liquid at room temperature for 2 months at 40° C. followed by 12 months at room temperature (“Long Term”). The visual inspection showed clear liquids at the end of the test periods.

(25) TABLE-US-00004 TABLE 3 Start Long Term Synative ® AL G16 (comparative) clear clear Propoxylate A clear clear Propoxylate B clear clear

Example 5—Foaming

(26) The formulation of example 4 was diluted with tap water to produce a transparent emulsion containing 5 wt % of the formulation. The shaking foam was evaluated as follows: In a 100 ml graduated cylinder with stopper 70 ml of the diluted formulation was carefully filled without generating foam. The the cylinder was shaken 20 times up and down, where one up-down-up process is recorded as one time. The maximum foam height was recorded immediately as the start time and the time intervals given in Table 4.

(27) The data demonstrated that the Propoxylate A, B and C generated less foaming that the comparative formulations.

(28) TABLE-US-00005 TABLE 4 Amount of Foam [ml] Propoxylate Propoxylate Propoxylate Synative ® AL A B C G16 (comparative) Start 25 26 34 40   1 min 5 24 28 38 2.2 min 0 — — —   3 min — 3 8 16 3.5 min — 0 — —   5 min 0 0 4 6

Example 6

(29) The pour point of the Propoxylates A, B and C was measured (DIN ISO 3016) and compared to C16/18 Propoxylate with 2.2 ethylene oxide units. The data in Table 5 demonstrated a very low pour point.

(30) TABLE-US-00006 TABLE 5 Propoxylate Propoxylate Propoxylate C16/18 Propoxylate A B C (comparative) Pour Point −51° C. −54° C. −62° C. 14° C.

Example 7

(31) Samples of the Propoxylate A, B or the comparative Synative® AL G16 were put with aluminum pans into an oven and heated up to 350° C. within 30 min, and then kept for 2 h at 350° C. Then the ash was determined and calculated by weight percent. The data in Table 6 demonstrated that the Propoxylate A and B had a cleaner burn off.

(32) TABLE-US-00007 TABLE 6 Synative ® AL G16 Propoxylate A Propoxylate B (comparative) Ash 0.12 wt % 0.10 wt % 0.34 wt %