US3444080A - Lubricant for rolling metals - Google Patents

Description

U.S. Cl. 25249.5 10 Claims ABSTRACT OF THE DISCLOSURE Soluble oil compositions comprising lubricating oil containing a fatty acid, a morpholine, and an alkylene polyol are useful in hot rolling of metals.

Background of the invention The subject matter of the invention pertains to lubricants containing an organic acid and a nitrogen-containing base. More particularly, it pertains to lubricants which may be either water-in-oil or oil-in-Water emulsions.

It is known from the prior art that satisfactory lubricants for use in hot rolling non-ferrous metals such as aluminum are obtained by admixing certain soluble oils with water to form emulsions. US. Patent No. 3,311,557 describes such a soluble oil which comprises a mineral lubricating oil containing an additive combination comprising an alkanolamine, sufiicient fatty acid to provide free fatty acid and an alkylene polyol. The soluble oil when admixed with water forms a finished lubricant for lubricant for use in hot rolling of, for example, aluminum. The lubricant provides good cooling and lubricating properties, bright surface finish, and resistance to staining and metal pickup.

Although the lubricants described in the above-mentioned patent are satisfactory in hot rolling non-ferrous metals, improvements with respect to lubricant emulsion stability, oil aging characteristics, and the method of preparing the oil, Would be highly desirable.

Summary It has now been described that the above-mentioned improvements in the lubricants described in US. Patent No. 3,311,557 can be achieved without adversely affecting the other properties and qualities of the oil by replacing the alkanolamine of the soluble oil with morpholine.

Description of the preferred embodiments Any mineral oil may be used as the base for the soluble oil. Preferably, the oil used is a HVI lubricating oil, i.e. one having the viscosity index (Dean-Davis of at least 80, preferably 90100. Mineral oil fractions of this type are derived from parafiinic, naphthenic or mixed base crudes. Viscosity as determined at 100 F. is in the range from about 75 to 250 SUS, preferably between 100 and 150. A typical mineral base of this kind is a high viscosity index refined mineral lubricating oil having the following properties:

GR, API 60 C 32.2 Color, ASTM 1 Pour point, F. 5 Flash, F. COC 370 Fire, F. 435 Viscoosity, SUS at 100 F. 103 Viscosity index 93 Neutralization number 0.01

The low and medium viscosity index oils (80 VI), however, may also be used as the mineral oil base for the soluble oils of the present invention.

The fatty acid used in the present composition includes fatty acids of from 12 to 30, preferably 14 to 18 carbon nited States Patent 9 F 3,444,080 Patented May 13, 1969 atoms and may be derived from animal, vegetable or mineral sources, such as fatty acid obtained from cotton seed oil, soy bean oil, coconut oil, corn oil, palm oil, lard oil, tallow and pure saturated and unsaturated fatty acids, such as stearic, oleic or linoleic acids. Oleic acid or mixed fatty acids having a high proportion of oleic acid are particularly suitable because of low melting point. A suitable fatty acid is sold by Emery Industries under the trade name of Emery 3305, the major constituents and approximate amount being oleic acid (45% wt.), stearic acid (15% wt.), linoleic acid (15% Wt.), and palmetic acid (15% M) A particularly suitable fatty acid is Emery 3252 which is of low melting point and results in an oil blend of low pour point. The amount of fatty acid used in the soluble oil is from about 10% to about 35% by weight and preferably from about 15% to 30% by weight.

Only sufficient morpholine is used to form the salt of a portion of the fatty acid so as to leave a relatively large amount of free fatty acid in the soluble oil, e.g. sufficient morpholine is used to combine with on the order of from about 1540% of the fatty acid. The amount of morpholine is controlled so that the ratio of the total base neutralization number-electrometric (TBN-E as determined by the ASTM 664 method) to the total acid neutralization number-electrometric (TAN-E as determined by the ASTM 664 method) of the soluble oil is in the range from about 0.15 to 0.4 and preferably from 0.15 to 0.3. In terms of percent by Weight of the composition this amount is from about 1.5% to about 2.0% of morpholine based upon the above quoted percentages of acid. The amount of morpholine is considered to be critical, since when this ratio is too low, emulsions of the soluble oil with water may have poor stability. At high ratios, pick-up of aluminum fines by the emulsions may become excessive.

Surprisingly, if cyclic amines other than morpholine are used to prepare the oils of the present invention, the resulting oils do not form satisfactory emulsions, e.g. oils containing aniline, pyridine, benzyl amine, p-aminophenol, p-phenylenediamine, p-anisidine, 3-aminopyridine, o-phenetidine, 2-pyridol, cyclohexyl amine, piperazine, or dicyclohexylamine show no ability to form emulsions; oils containing piperidine and 2,6-dimethylmorphine yield emulsions, but of poor quality; and oils containing N- methylmorpholine yield emulsions which are inferior to morpholine-containing oils, but better than oils containing any of the other cyclic amines.

Alkylene polyols suitable for use in the composition of the invention are those wherein the alkylene group has from 4-8 carbon atoms. Particularly suitable and preferred alkylene polyols are the diols, such as hexylene glycol, 1,2-hexane diol, 1,5-pentane diol, 1,5-hexane diol and the like. From about 2 to 15% by weight and preferably from 8 to 12% by weight of the alkylene polyol is used in the soluble oil.

Other additives can be added to compositions of this invention in order to improve their performance. For example, emulsions containing fatty acids are susceptible to deterioration, especially when used at elevated temperatures for long periods of time. Such emulsions develop an extremely strong, foul and undesirable odor which renders them objectionable. It is generally desirable to add a small amount of a germicidal agent to inhibit bacterial growth and fermentation. Formalin (aqueous solution of approximately 40% formaldehyde) and phenolic compounds, e.g. phenol, chlorophenols such as tetrachlorophenol, phenyl phenols such as o-phenyl phenol, and the like are Well known germicidal agents. The phenolic germicidal agents are preferred and are available commercially. The amount of germicidal agent used generally does not exceed 5% by weight, usually from 0.1-

1% by weight added to the soluble oil is very effective. Minor amounts, e.g., 0.l1% by weight of antioxidants can be used. A highly suitable antioxidant is 2.,6-ditertiary butyl-4-rnethyl phenol.

Illustrative examples of soluble oils of this invention comprise:

Composition A: Percent weight Emery 3305 fatty acid 23.0 Morpholine 2.0 Hexylene glycol 10.0 HVI neutral (VI 94, 105 SUS at 100 F.) 65.0

100.0 Composition B:

Oleic acid 20.0 Morpholine 1.6 Hexylene glycol 11.0 Minerallubricating oil (same as A) 67.4

100.0 Composition C:

Oleic acid 17.0 Morpholine 1 .5 Hexylene glycol 8.0 Mineral lubricating oil (same as A) 73.0 Germicidal agent (0.25% Wt. Dowicide C.O.

+0.25% wt. Dowicide 6) 0.5

100.0 Composition D:

Emery 3305 fatty acid 23.1 Morpholine 1.7 1,5-Pentane diol 10.0 Mineral lubricating oil (same as A) 65.2

100.0 Composition E:

Emery 3252 fatty acid 23.2 Morpholine 1.8 Hexylene glycol 10.1 Mineral lubricating oil (same as A) 64.4 2,6-ditertiary butyl-4-methyl phenol plus 50 p.p.m. by weight Dow Corning Antifoam A 0.5

100.0 Composition F:

Emery 3305 fatty acid 12.0 Morpholine 1.7 Hexylene glycol 4.0 Mineral lubricating oil (same as A) 82.3

100.0 Composition G:

Emery 3305 fatty acid 25.0 Morpholine 2.9 Hexylene glycol 12.0 Mineral lubricating oil (same as A) 60.1

100.0 Composition H:

Emery 3305 fatty acid 20.0 Morpholine 1.4 Hexylene glycol 8.0 Mineral lubricating oil (same as A) 70.6

100.0 Composition I:

Fatty acid 23.0 Morpholine 1.85 Hexylene glycol 10.0

Mineral lubricating oil (major amount).

In preparing the soluble oil of the present invention the components are merely blended together using conventional mixing means, such as mechanical agitation. Heating may be used, if desired, to facilitate blending, e.g. temperatures of from F. to 120 F. The preparation of the instant morpholine-containing soluble oils is relatively simple when compared to the involved cooking steps required in preparing the alkanolamine-containing soluble oils of the prior art.

Finished emulsions are prepared by admixing, on a volume basis, from about 2% to about 10%, preferably about 3% to 6% soluble oil with water. In general, the present soluble oils can be used in concentrations lower than those used with conventional soluble oils which is advantageous from a cost standpoint. The emulsions form quite readily, which is an important factor since the mixing of the oil and water is done in the field by means such as air agitation, propeller mixing and the like. The composition of the emulsion yields a proper balance among the forces of attraction operating between the oil and water phase, the oil phase and the metal, and the water phase and the metal. The composition of the emulsion is such that an oil-in-Water emulsion and a water-inoil emulsion are almost equally likely to form spontaneously, yet the resulting emulsion is quite stable.

Typical properties of the compositions of the invention are given in Table 1.

TABLE 1 Property: Value Gravity, API at 60 F. 29.5 Color, ASTM 2.0 Pour point, F. 0 Cloud point, F. 28 Flash, F. 300 Viscosity, SSU at F. 113 SSU at 210 F. 40.6 W (ASTM D-567) l. 100 Initial pH 7.5 TBN-E, mg. KOH/g. of oil 12 TAN-E, mg. KOH/g. of oil 44 Ratio TBN-E/TAN-E 0.27 Saponification No. 45

Sulfated ash, percent w. 0.002

To illustrate other properties and qualities of the compositions of the present invention, a comparison is made with a soluble oil (Composition X) comprising:

Percent wt. Emery 3252 fatty acid 25.0 Hexylene glycol 7.5 Diethanolamine 1.5 Mineral lubricating oil (same as A) 66.0

Plus 0.5% W. 2,6-di-t-butyl-4-methyl phenol and 50 p.p.m. Dow Corning Antifoam A.

Since in many instances the soluble oil will be stored prior to preparing the emulsion or finished lubricant, the tendency of the oil to deteriorate when stored is important. To measure this tendency the emulsion stability of emulsions prepared from Compositions E and X was determined using new oil, oil aged at F. for 14 days (equivalent to 2 months at 77 F.) and 110 F. for 28 days (equivalent to 4 months at 77 F.). The emulsion stability is indicated by preparing an emulsion of oil (6% v.) and distilled water, allowing the emulsion to stand 8 hours, and then measuring separation of oil and water from a 100 cc. sample. The results of this test are given in Table 2 below.

TABLE 2.-STORAGE EFFECT ON EMULSION STABILITY The data of Table 2 demonstrates that the compositions of the present invention have less tendency to deteriorate during storage than similar compositions containing an alkanolamine rather than morpholine.

Aging of the emulsion itself is indicated by a test which consists of preparing an emulsion having 3% v. oil and 97% v. distilled water, stirring the resulting emulsion at 180 F. for 14 days with make-up water being added as needed to simulate service conditions, and measuring separation of oil and water from a 100 cc. sample as before. Also the aluminum fines suspension test was carried out to measure the afiinity of the oil for metal. The test consists of mixing 0.1% W. aluminum fines (95% through 200 mesh, 80 to 90% through 325 mesh) with 500 cc. of an emulsion composed of 6% v. oil and 94% v. distilled water. The mixture is shaken for 2 minutes and allowed to stand for 10 minutes in a 500 cc. graduated cylinder. A pipette is used to withdraw a 50 cc. sample from the middle of the mixture which is contained in the 500 cc. cylinder. The remaining steps consist of filtering the sample through an asbestos pad in a Gooch crucible, weighing the amount of aluminum recovered from the sample, and recording the percent of fines which remains dispersed. A small percentage is desirable. The pH of the emulsion is also given in Table 3. The results of these tests are given in Table 3.

1 Trace oil. 0.5% cream. 2 Trace oil, 1% cream. a Trace oil, 1.5% cream.

The data of Table 3 show that the composition of the present invention which contains morpholine rather than a dialkanolamine is more stable than Composition X and gives satisfactory results with respect to metal pickup. The constant pH of 8.0 shows that the emulsion has good resistance to air oxidation.

I claim as my invention:

1. A soluble oil suitable for use in hot rolling nonferrous metals which comprises a major amount of a mineral oil, from about 10% to about 35% by weight of a fatty acid having from 12 to 30 carbon atoms, from about 2% to about 15% by weight of an alkylene polyol wherein the alkylene group has from 4 to 8 carbon atoms, and from about 1.5 to about 2.0% by weight of morpholine.

2. The soluble oil of claim 1 wherein the amount of fatty acid is from 15 to 30% by weight and the amount of alkylene polyol is from 8 to 12% by weight.

3. The soluble oil of claim 2 wherein the alkylene polyol is hexylene glycol.

4. The soluble oil of claim 3 wherein the fatty acid comprises oleic acid.

5. The composition of claim 4 wherein the composition comprises about 23% fatty acid, 10% hexylene glycol, and 1.85% morpholine.

6. The composition of claim 5 containing from about 0.1% to 1% by weight of 2,6-ditertiary butyl-4methyl phenol.

7. The composition of claim 5 wherein the mineral oil has a viscosity at F. of from 100 to SSU.

8. An aluminum hot rolling composition comprising a major amount of water and from about 2 to about 10% by volume of the soluble oil of claim 1.

9. An aluminum hot rolling composition comprising a major amount of water and from about 2 to about 10% by volume of the soluble oil of claim 5.

10. An aluminum hot rolling composition comprising a major amount of water and from about 2 to about 10% by volume of the soluble oil of claim 6.

References Cited UNITED STATES PATENTS 2,815,560 12/1957 Buxton 25252 XR 3,071,544 1/1963 Rue 25249.5 XR 3,268,447 8/1966 Dickey et a1. 252515 XR 3,311,557 3/1967 Schiermeier et a1. 25252 XR DANIEL E. WYMAN, Primary Examiner.

W. I. SHINE, Assistant Examiner.

US. Cl. X.R.