US2947692A - Metal drawing lubricant - Google Patents

Description

United States Patent METAL DRAWING LUBRICANT Everett C. Hughes, Shaker Heights, and Harrison M. 'Stine, Lyndhurst, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Filed Nov. 9, 1956, Ser. No. 621,214

1 Claim. (Cl. 252-48) The present invention relates to a method of drawing metals such as in the cold drawing of steel rods and the drawing of aerial bomb noses and to an improved lubricant for such operations.

, Drawing involves the plastic deformation of metal by a hard steel die. High temperatures and pressures are generated between the die surface and the metal being drawn, and sutficient lubrication is required in order to prevent adhesion of the metal to the die surface and to prevent scratching and tearing of the surface of the drawn object. It is necessary for drawing fluids to cool the metal, reduce friction, and diminish seizure. Ease of application and removal of the drawing fluid from the surface of the metal are also important considerations.

Heretofore, mineral lubricants, fatty lubricants, soaps and waxes have been used to provide lubricating films for this type of operation, and a typical drawing compound of the prior art may include sulfurized olein, castor oil and sodium soap. Inert solid materials such as calcium carbonate have also been used as components of lubricating compositions designed for metal drawing operations and have proved to be of great value in forming a solid film between the metal and the die, thereby preventing metal to metal contact under high pressures.

Metal drawing compounds are customarily supplied to the trade as relatively viscous compositions some of which are intended to be diluted with oil and others to be diluted with water-as dictated by the particular requirements in each mode of use. A drawing compound containing an inert solid material, such as calcium carbonate, which can be diluted satisfactorily with either oil or water is desirable. Such a compound must possess the following characteristics:

(1) It must be capable of dilution with oil without settling of the inert solid material.

(2) It must be capable of dilution with water and capable of holding the inert solid material in suspension.

(3) It must' remain the proper consistency when has not been solved. Inert solid materials such as calcium carbonate are not readily suspendable in water and the problem of obtaining a good suspension, in the case of a drawing compound, is complicated by the requirement that the drawing compound be dilutable also with oil.

Another complicating factor is that the compound must be of suitable viscosity for dilution.

In accordance with this invention, there is provided a drawing compound which can be diluted with either oil or water to provide a highly satisfactory lubricant for drawing operations. The lubricants thus prepared provide both oiliness lubrication and solid film-type lubrlcain certain proportions to provide a formulation which meets all of the aforesaid requirements. The compositions include a suspended phase and a suspending phase. The suspended phase includes bentonite and an inert solid material having a hardness of 13.5 on Mohs scale. The suspending phase includes a mineral lubricating oil and an emulsifying agent. The proportions of the ingredients must be so balanced that the suspended phase comprises from 60-75% by weight of the composition and the suspending phase from 40-25% by weight of the composition.

The mineral oil used in the formulation may be any mineral lubricating oil such as conventionally refined neutral oil, solvent extracted oil or any lubricating oil having a viscosity within the range of about 50 to about 500 Saybolt Universal seconds at F. The mineral oil is generally the major ingredient of the suspending phase and may comprise from about 50-88% by weight of the suspending phase. The mineral oil serves a dual role in the composition. It is both a carrier for the inert solid material and it is an auxiliary lubricant.

The emulsifying agent can be any of those surface active agents which are commonly used in the preparation of emulsions, particularly oil-in-Water emulsions, such as alkali metal, ammonium or hydroxylamine salts of fatty acids, petroleum sulfonates including long chain alkyl sulfates and alkyl-aryl sulfonates, polyoxyethylene derivatives of phenols, alcohols, etc., and the like. Preferred emulsifying agents are the sodium salts of petroleum sulfonic acids having molecular weights between 375 and 525. In addition to the emulsifying agent, emulsion stabilizers such as glue or gelatin may also be employed.

The amount of emulsifying agent is not critical. Any amount that emulsifies oil in water in the usual range of dilution intended for the drawing compound of this invention may be employed. Generally, it is preferred to employ from 1250% of the emulsifying agent based on the Weight of the suspending phase. When petroleum sulfonates are used as the emulsifying agent. the maximum amount to be employed is limited by the viscosity to the composition, because petroleum sulfonates are relatively viscous materials. However, higher concentrations of petroleum sulfonates can be used with mineral oils in the lower part of the viscosity range given herein above.

Among the inert solid materials which may be used are those which are substantially insoluble in water or oil and have a hardnessof 1 to 3.5 on Mobs scale of hardness. Such substances include calcium carbonate, zinc sulfide, lithopone, talc, and other types. of clay. The inert material is employed in finely divided form and is preferably fine enough to pass a mesh screen.

A hydrophilic bentonite is employed to maintain the inert solid, such as calcium carbonate, in suspension in the suspending phase of the mixture, after dilution with water, as a result of the formation by the water and the bentonite of a thixotropic gel. The bentonite employed is preferably ground to a fine, odorless gritfree powder, having a particle size sufiiciently small to pass a 200 mesh screen. For the purpose of this invention, it is necessary that the bentonite be in its natural state as in this state it is highly hydrophilic. Organ'ophilic bentonites are not suitable for the purposes of this invention.

'Bentonite and the inert solid material together comprise the suspended phase. The inert solid material comprises the major ingredient of the suspended phase and is preferably employed in amounts ranging from.85-97.% by weight of the suspended phase and the bentonite .in amounts ranging from 15-3% by weight of thesuspended phase. E

A most important factor in the compositions of. this invention is the proportion of the suspending phase" to the suspended phase which is controlled by the consistency of the composition and its stability against separation into two phases. It has been found, for example, ha a c n entra io i h of he su nd d f he ximm, amou t t at c n, be o a d o produce acomposlition with a workable consistency to per.- f ss f rr n "n. th t er, han abo 60% y tl Qf the suspended phasewas found. tobelower eau e omp si s s onta n s Q1 m t e 'efd, 'e aratiqn.q o lpro on sd tandina e dilution of the. drawingc'ompound of this inventedonly by the stability of. the suspensionof; a a n th Q n asaq he qr l iqn- It has beenfound thatthe drawing compound may be diluted wit se eral mes ts wn We g f. i he oil te Gen, owever, the de gree ot dilution will be he qsi v. dcsi d a h i ular haw-ins .n at qn o. he .p ftt me preferred lubricating composition consists of 18%. e sht f, q itim llrfin neu al. o 2%. y. t. stenc l b i mupq o eum fo at of hae fi hdgany acidtype such as, hoseavai a e e i the t rade v names, Petronate, Retromix No. 9, and Hardesty Basel-9,? 64% by weight of precipitated .calciumcarbonate, and 6% I by weight of a natural bentonite. invention; will be. further illustrated by reference tg the following specific examples:

n EXAMPLE: 1

One hundred pounds of a soluble oil consisting of (39% weight of a conventionally refined neutral oil having a. viscosity of lQOSUS' at 100 F and 40% by of. an enuils ifying agent composed of a sodium petroleum sul fonate having a molecular weight ofvabou t were placed; in a vessel. Twohundred ten pounds of precipitated calciumcarbonate and pounds of atura .v bea i e gro nd, o; Pa mesh creen were, slowly added to the soluble .oi l While agitating the ixture it n -barre size L h n m e A smoothcreamy paste resulted.

The u i a compoun was lu e r, us n a drawingpperation with 1% volumes of water per volume a drawin w n EXAMPLES ,2 THROUGH- l2 Aeseries of formulations preparedusing the procedure andingredientsof Example 1. The proportions of ingredients and observations. appear in the following table! p Allofatl e. compositionstor Whiihdata are given in Tabled ..have.proved ;to-,he satista ctory. It. is desirable that the compositions prior to dilution have a viscous paste-like consistency so that they may be easily admixed with water or oil and this characteristic is possessed by the undiluted compositions of Examples 2, 7, 8, and 9. Similarly, it is desirable that the compositions, before dilution, be stable againstseparation of the two phases and this prope y; als is po es ed y he wmpositions of Examples '2, 7, 8, and 9. It should be noticed that bleeding; is a-jfatal defect: if the compositions can be readilyv redisper sed. Although some bleedingoccurred in the compositions of 'Examples '7, 8, and 9; the composii n a e, neuenhe s sawspt hle sqaus the ea i redispersible.

After dilution, it-is desirable that" the diluted compositions have a consistency somewhat like that of heayy cream andall'of ihe diluted compositions, i.e. Examples 3, 4, 5 6', 10, 131, and 12-,jhave desiredconsistency. Similarly, 'the diluted compositions also must be stable against separation into two phases,i',e. a suspendedph ase id 8 usi n ne ase 7 0? he .d ed'a m q q are satisfactory in this respect; Itis noted that-a slight amount of calcium carbonate precipitated to the bottom of the compositionsqf- Examples l1" and'-1 2 on standing. Hgwever, -tl;je amount of' precipitate was so, small as 1 156. ne g b e an v no ie t a b The examples adequately illustrate the adaptability of thercon p ositions of thi s invention to dilution with either a l, orq i n flie. wmrao t a s a r t y a 'i s not possessed by competitive products. A Q

es f, he ubr ca n qmp a n. aw ne a r i ns. shawsd he qmp u ds o h r atis r t fv oth h n i uted w wa e aa i h. il n s. o ra isu nvolv n he. r w a of o s s he. tee new ith ut. rink n Q br a a t nd PQ iS iQEV qffliedis wa 7 eq i e i tinalhe ntir e tr r dn m lsion nre at sl fr m. h lubrisat ns c oa nosit n ofEiwtnpl n r n ed atisfac qril nf e rawia of,ro ds,fronr0.; inch to 0,63 inch. i

t r e obv ou ths ic. kil s r a the rt h tman modifications maybe made within the scope of the pre en on ithout. dsaa tias rsznaths s iri he az a a t staistqbslrestri tediuasw daa c ,qa Q i h da sa s.

An inul ifia le. ubfic im rz sitian compris n .0 to 75%.hvweiehtnf, asusn ade phase cns s inaes m ia v f, boutisfi c y. ei h -o a ue ts Zdl mater al ,selestetl f tn. the r u w sis s.v of .cal carbonate, zinc sulfide, lithopone, ;ant1 ?l. havinga d; ess .1. p nMohs. a e an apar c e s e te fi enough to p 591mm. sm aaaBdabQQtJ19 Table-l [Wtapercent concentrationbt components} Dilution on v01. 7 My 0500 'Bent ntte E nlslfy St bill s' o ,@m :a t ExampleNo. ,(Ground), .200 mesh. lug Agent 011, C.R.N.eutral 1 isiin aiiiii mesh.. VoLQlb Vol. H 0 (Diamond Paraffin a 67.0 6.31 10.7 16.6.... t 67.0., 6.13 10.7 16- verwe ttstacgory (he vy-cream.

V conssenc 67.10 6.3 10.7 16 3., isattstactoriiy' 67.0 6.3, 10.7 8 Satlstactoxyteasfly.dispersed). 66.9 6.4- 5.3 Nagy sagistact'ory (overnight 7 7 ea, in; 66.9 6.4 5.8 21.4 1695 gleedin g (readily redls parse 66.!) 6,4. 5.3. sn g- 1 1.4 S,.E. 10% bleedingcneadlly *il'elusq:

parse 66.9 V 6.4 4.3- 22.4S.E. 500sec. I I 118% bleeding (readily redis- 63 5' 61 i 122 13 3 1 v iirt' V i M x --.a sanacor. 63.5- 6.1 12.2 18.3-. 3 sll amountf of-carbgnate at 63. 5 5.1 x 12.2 ms a -1 6 References Cited in the file of this patent UNITED STATES PATENTS Cross Dec. 17, 1929 Adams Aug. 16, 1932 Rader Aug. 6, 1940 Zimmer Oct. 7, 1941 Roden Dec. 14, 1954 Reamer Nov. 1, 1955 Spring Aug. 28, 1956