US3304257A - Lubricants - Google Patents

Description

United States Patent 3,304,257 LUBRICANTS Wilhelm Schauzer, Munich, Germany, assignor to Molykote Produktions G.m.b.H., Munich, Germany No Drawing. Filed July 19, 1965, Ser. No. 473,190 Claims priority, application Germany, July 22, 1964,

6 Claims. (Cl. 252-25) This invention relates to novel lubricants which are particularly useful for cold-drawing and otherwise cold shaping metals without splintering the metal.

In deep drawing and shaping metals and similar metal processing wherein significant frictional forces are encountered, the formation of splinters and other difficulties necessitates the use of lubricants. The tools employed for drawing, shaping and forming metals are of great value and must be conserved else their use is economically unfeasible. Further, the development of hot spots and localized overheating, formation of channels, scratches, gouges and pits on the surface of the metal article being processed is wholly undesirable. To avoid damage to the tools employed and to the metal article being processed it is customary to employ a variety of lubricants. The lubricants for metal drawing can be in the form of fluids, pastes, fatty materials as well as solid lubricants. The important characteristic of the lubricants for this use is the reduction of the heating eifect caused by working the metal and this cooling can be accomplished by dissipating the heat at a rapid rate as well as by actual reduction of friction, etc.

Heretofone, soaps such as alkali metal and alkaline earth metal salts of higher fatty acids, 'boric acid and derivatives of boric acid in the form of solids, in aqueous systems, in oily systems and in paste-like preparations have been used as lubricants in the deep drawing of metals. Similarly employed have been inorganic solid lubricants with layer lattice structure. The use of phosphate compounds in such lubricants is also known.

The primary object of this invention is to introduce a novel lubricant for use in deep drawing, forming and machining of metals. Other objects and advantages of this invention are detailed in or will be apparent from this disclosure and appended claims.

It has been unexpectedly found and this invention teaches that aluminum salts of phosphorous-oxygen acids are eminently useful as lubricants for cold processing of metals.

The aluminum salts employed herein are formed from phosphorous-oxygen acids wherein the phosphorous is electropositive and is trior pentavalent. Examples of such acids are ortho, pyroand meta-phosphoric acids, ortho-, pyroand meta-phosphorous acids and the known oligomeric and polymeric phosphorous-oxygen derivatives.

The aluminum salts of the phosphorous-oxygen acids can be employed in a wide variety of forms. They can be employed as dry lubricants alone or in mixture with other lubricants. When these salts are added to other lubricants, it is preferred that they be present to the extent of at least 1% by weight, based on the mixture. Thus, they can be mixed with extenders and/or other lubricating solid organic or inorganic carriers. For example, the aluminum salt can be mixed with polytetrafluoroethylene, polychlorotrifluoroethylene powders or with metal sulfide "ice lubricants and the mixture can be incorporated or worked into organic plastics. Furthermore, the aluminum salts can be admixed with mineral oils and known synthetic lubricating oils as well as petroleum products to produce a variety of lubricants varying from fluids to pastes. Incorporation of the aluminum salt in a wax-like lubricant provides lubricating sticks which can be readily employed in a wide variety of applications. Lubricating greases and viscous natural and synthetic carriers can also be admixed with the aluminum salt to produce a grease or paste-like mass and the carrier may itself be a lubricant.

The aluminum salt can be uniformly distributed throughout the carrier or admixed ingredients in any manner desired. Generally the even distribution is more easily accomplished in the presence of viscosity-modifying materials or materials capable of effecting thixotropy.

The aluminum salts can, of course, be added to fluid carriers which can be inorganic or organic, natural or synthetic but should 'be of sufliciently low viscosity to accomm-odate the aluminum salt without forming a paste of viscous fluid. Such fluid carriers as water, alcohols, mineral oils, polyester fluids, polyphenyl ether and the like can be employed. The fluid carrier can be nonlubricating or it can be a lubricant which is relatively inferior, superior or equal to the aluminum salt. It is generally preferred to employ a lubricating fluid as a carrier if the ultimate product is to be in fluid form. The fluids should contain dispersion stabilizers to insure a uniform product of uniform characteristics.

Basically, the aluminum phosphorous-oxygen compounds used as lubricants in the present invention can be used together with other lubricating materials and other compounds common in the lubricating art, as for example, emulsifiers to make articles easier to clean. The corrosion inhibiting properties of the aluminum phosphates can be augmented by the addition of other corrosion inhibitors.

The following examples serve to clarify the discovery. They also serve to illustrate the exaellent results obtained by observing the teachings of the present discovery.

EXAMPLE 1 Aluminum phosphate in. water The friction scar area was measured on the Reichert friction and wear tester under 30 kg. load and 100 m. sliding contact. Water was employed as the lubricant and the resulting scar area had an average value (three measurements) of 32.6 sq. mm. A mixture of 5 parts by weight aluminum phosphate and 95 parts by weight water was employed as the lubricant and the test was repeated. The friction scar area had an average value (three measurements) of 7.3 sq. mm.

EXAMPLE 2 Aluminum phosphate in emulsions Following the procedure of Example 1, a mixture of parts by weight mineral oil, 9 parts water and 1 part emulsifying agent tested as a lubricant on the Reichert friction and wear tester gave an average friction scar area of 37.2 sq. mm. A mixture of par-ts of the mineral oil, Water, emulsifying agent mixture and 5 parts by weight of aluminum phosphate, similarly tested gave an average friction scar area of 22.9 sq. mm.

3 EXAMPLE 3 Aluminum phosphate in greases A lithium soap grease was tested on the Almen-Wieland lubricant testing machine and on the Shell four-ball extreme pressure lubricant testing machine. A four percent by weight loading of aluminum phosphate was then added to the lithium soap grease and the tests were repeated. The results are tabulated below:

Aluminum phosphate in pastes A mineral oil was tested on the Almen-Wieland machine and thereafter 30 parts by Weight aluminum phosphate was mixed with 70 parts by weight of the mineral oil and the mixture was also tested on the Almen-Wieland machine. The mineral oil had a loading capacity of 200 kg. and the mineral ioil-aluminum salt mixture had a loading capacity of 800 kg.

EXAMPLE 5 Results equivalent to' those set forth above were accomplished when aluminum salts of metaphosphoric acid, phosphorous acid, pyro'phosphoric acid, pyrophosphorous acid and metaphosphorous acid were substituted for the aluminum phosphate (eg. in Example 4).

That which is claimed is:

'1. A lubricating composition containing at least 1 percent by Weight of an aluminum salt of an acid selected from the group consisting of phosphoric and phosphorous acids.

2. A fluid lubricant containing 21()% by weight of an aluminum phosphate.

3. A lubricating oil containing 24% by weight of an aluminum salt of a phosphorous-oxygen acid selected from the group consisting of phosphoric and phosphorous acids.

4. A lubricating grease containing 15-40% by weight of an aluminum salt of a phosphorous-oxygen acid selected from the group consisting of phosphoric and phos phorous acids.

'5. A novel lubricant particularly useful for splinterfree cold met-a1 processing characterized by the presence of at least 1 percent by weight of an aluminum phosphate in the lubricant.

6. in a lubricant, the improvement comprising incorporating therein at least 1 percent by weight of an aluminum salt of an acid selected from the group consisting of phosphoric and phosphorous acids.

References Cited by the Examiner UNITED STATES PATENTS 1,932,454 10/1933 Franks 252-25 X 2,588,234 3/1952 Henricks 25225 X 3,186,945 6/1965 Graue et al. 252- 25 DANIEL E. WYMAN, Primary Examiner.

C. F. DEES, Assistant Examiner.

Claims (1)

1. A LUBRICATING COMPOSITION CONTAINING AT LEAST 1 PERCENT BY WEIGHT OF AN ALUMINUM SALT OF AN ACID SELECTED FROM THE GROUP CONSISTING OF PHOSPHORIC AND PHOSPHOROUS ACIDS.