DK145231B - LUBRICANT FOR USE IN METAL WORKING AND USE OF THE LUBRICANT - Google Patents

Description

(19) DENMARK \ κ ^ /

© (12) PUBLICATION <«) 145231 B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 4445/75 (51) Int.CI.3 C 10 M 1/26 (22) Filing date 2 Oct. 1975 C 10 M 3/20 (24) Running day 2 Oct. 1975 (41) Aim. available Apr 4 1976 (44) Submitted Oct 11 1982 (86) International application no.

(86) International filing day (85) Continuation day - (62) Master application no. -

(30) Priority Oct. 1974, 511776, US

(71) Applicant ALUMINUM COMPANY OF AMERICA, Pittsburgh, US.

(72) Inventor James Estell Knepp, US.

(74) Associate Engineer Hofman-Bang & Boutard.

(54) Lubricant for use in metalworking and the use of lubricant.

The invention relates to a lubricant for use in metalworking, in particular a lubricant for metalworking which can be used in the drawing and smoothing of sheet metal material, and an application of the lubricant.

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^ In the manufacture of metal for intricate shapes, such as e.g.

N the drawing and smoothing steps used in manufacturing fj! of a formed container or can from a plate of e.g. aluminum or steel, there are usually a number of different lubricants involved. There are residual oil residues on most plate surfaces resulting from previous rolling and fabrication operations; a further process lubricant is used for the smoothing operation, and yet another lubricant, namely the mechanical or hydraulic lubricant associated with the pressing equipment, may be at least partially inadvertently mixed with the process lubricants. Normally, these lubricants have different consistency, although it is known to use the same lubricant in both pulling and smoothing operations, albeit in different concentrations.

It is known to mix carboxylic acids, such as fatty acids, with mineral oils to make lubricants. Eg. both U.S. Patent Nos. 2,124,628 and 2,151,353 disclose the use of oleic acid with a mineral oil as a lubricant. However, such lubricants were usually used as pure oils in the 1930s, i.e. they were not further diluted by dispersion or emulsification in an aqueous medium, as is common practice today.

It is also known to disperse fatty acid esters and soaps in mineral oil lubricants. However, such lubricants are difficult to work with in the sense that filters used to filter out impurities and foreign materials (such as metal shavings or the like) are clogged by the soaps. Further, such lubricants containing soaps are usually somewhat alkaline (pH of about 8 or 9), and subsequent treatment of the formed metal piece with acidic cleaners to remove the lubricant therefrom tends to degrade the soap and thus the lubricant cannot be recycled. or reused.

It has also been found in connection with many known lubricants that the residual oils already present on the metal material are not compatible therewith, further providing a contamination type effect. The same applies to the hydraulic and mechanical oils used in the presses, which provide a contamination of the lubricant therefor, rendering them unusable for re-use without re-treatment, because inevitably some mixing occurs.

U.S. Patent No. 3,657,126 discloses an emulsifiable lubricant comprising the combination of a dispersion of an aliphatic carboxylic acid glycol ester in mineral oil with an ear-emulsifier to provide emulsification or dispersion of the pure oil in an aqueous medium. While this lubricant has been effective in certain metalworking operations, it has been found that many of the problems enumerated above still exist when using this oil for tensile and smoothing lubrication.

The invention therefore relates to a lubricant which is dispersible or emulsifiable in water and which can be used at some established concentration both as a drawing and smoothing lubricant, where it can also be used (as a pure oil) as the hydraulic and / or mechanical oil. , which will be compatible with the residual oils usually present on the metal material as a result of prior manufacturing operations. The invention also relates to a lubricant which will be chemically stable in the presence of further acidic purification treatment to remove the oils from the metal, thereby allowing recycle of the lubricant without loss resulting from contact with the acid. The present invention will be apparent from the description of the accompanying flow diagram.

The accompanying drawing is a flow diagram illustrating the components of the lubricant according to the invention.

The lubricant according to the invention, which is of the kind specified in the preamble of claim 1, is characterized by the characterizing part of claim 1.

The constituents can be further dispersed in an aqueous medium comprising deionized water or soft water containing less than ca. 250 ppm hardness. Preferably, the amount of the ingredients referred to hereinafter as the pure oil will be between 4 and 30 parts per 100 parts of the dispersion (pure oil) water. In the present specification, the terms "emulsion" and "dispersion" will be considered identical concepts.

The use of the lubricant according to the invention is characterized by the characterizing part of claim 9.

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The viscosity of the total blend of pure oil should be at least approx. 250 to 450 universal Saybolt seconds (SSU) at 38 ° C, although a somewhat higher viscosity can be used, such as 500-550 SSU (at 38 ° C) when operating at a higher temperature in the treatment equipment. Depending on the amount of the ingredients other than the mineral oil and their effect on the viscosity, the viscosity of the mineral oil will be chosen such that the mixture will have this final viscosity.

In accordance with the invention, the carboxylic acid useful in the invention must possess a good film strength or good load-bearing properties; preferably it should also be able to disperse formed fine metal particles, i.e. have no tendency to agglomerate fine metal particles. It should be sufficiently soluble to have a true solubility at 21 ° C, i.e. it should not become paste-like or only partially soluble when cooled to about room temperature.

The carboxylic acids useful in the invention may be monomeric, straight chain monocarboxylic acids, as well as isomers and dimers of such acids. In general, the carboxylic acids useful in the invention have the formula: ° m%, η-η + 1 C00H> where: m is an integer of at least 11, preferably at least 13; not above 34, and preferably not above 17, and where n is 0 or an even integer between 2 and 6.

Examples of high molecular weight monocarboxylic acids that fit into the above category include oleic acid, linoleic acid, stearic acid, linolenic acid, palmitic acid, myristic acid and lauric acid, as well as isomers of any of the acids listed above.

The aliphatic carboxylic acid ester component of the lubricant comprises the esterified product of monocarboxylic acids of at least 4 carbon atoms with monoalcohols or polyhydroxy alcohols (polyols), including polyhydroxy polyether alcohols. Examples of the monocarboxylic acids which can be used in the ester include butyric acid, capric acid, caprylic acid, capric acid, lauric acid, myristic acid and palmitic acid. Examples of such alcohols include methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol, glycerol, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol. The acids which have been esterified with the alcohol may comprise only one acid or it may be a mixture of acids. A commercially available example of a mixture of such acids is Hallco Plasticizer 4141 sold by C.P. Hall Company which comprises a triethylene glycol caprate caprylate.

The emulsifier or dispersant used in the lubricant of the invention comprises one or more nonionic and nonmetallic emulsifiers which may be an ether or preferably an ester. Such emulsifiers useful in the invention include polyoxyalkylene oxide ethers or esters of C 12 "C 18 alcohols or acids, sorbitan fatty acid esters and chemical or physical mixtures of such ethers and esters. Examples of such compounds include polyoxyalkylene oxide ethers such as polyoxyethylene polyoxyalkylene oxide esters such as polyoxyethylene stearate and polyoxyethylene oleate, sorbitan esters such as sorbitan monolaurate and sorbitan monoleate, or mixed esters such as polyoxyethylene sorbitan monoleate. emulsifiers when there is insufficient stirring or mechanical movement to maintain the emulsification, for example, it has been found that 4 parts of an ether emulsifier per 100 parts of lubricant is sufficient when using stirring, such as by stirring or pump recycling or the like.In other cases , wherein the plate to be manufactured, e.g. however, it has been found that additional emulsifiers must be used, preferably at least a portion of which are ester-based emulsifiers.

The remaining part of the pure oil comprises mineral oil. The mineral oil preferably has a viscosity of more than 250 SSU to provide sufficient viscosity after dilution with the other ingredients to provide a final viscosity of the pure oil of between 250 and 450 SSU, and preferably from 550 to 400 SSU, although as stated in the foregoing may use higher viscosities when operating at higher temperatures in the processing equipment.

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It should be noted that if necessary or desired, minor amounts of other additives such as corrosion inhibitors, bactericides or the like may be added.

The following examples will serve to further illustrate the invention.

EXAMPLE 1 5 parts by weight of oleic acid were mixed with 15 parts by weight of triethylene glycol caprate caprylate (C.P. Hall Plasticizer 4141), 3 parts by weight of polyoxyethylene-lauryl ether (Brij 30) and 77 parts by weight of a mineral oil having a viscosity of approx. 1,000 SSU (Circo X Heavy). The resulting oil was diluted with water to form a series of emulsions with a ratio of 1 part pure oil to 3-9 parts water respectively (by volume). The resulting emulsions had pH values in the range of 5 to 6. In addition, the pure oil was used as the mechanical oil in the drawing press and smoothing press used to conduct the experiments. A 3004-H19 aluminum alloy metal containing residues of roller lubricants on the surface was drawn and smoothed to form cans using the above-mentioned lubricant dilutions of the invention. The resulting cans were examined and found to be superior in comparison to cans prepared under similar conditions using conventional water-mixed lubricants. Further, it was found that the lubricant actually "cleaned" the smoothing equipment and the starting groove machining by dispersing the remaining metallic degraded material in the lubricant.

After drawing and smoothing the material, the drawn and smoothed cans were washed with water, then in a detergent with a pH adjusted to 1.6 with sulfuric acid, followed by subsequent washing with water and a final drying. The remaining lubricant on the drawn and smoothed cans was removed by these washes and recovered by a foam operation. It turned out that the recovered lubricant was not degraded by the action of the acid. The filters used in circulating the lubricant were examined after the tensile operation to determine if any soap formation had occurred resulting in a clogging of the filters used to clean the filter materials. It turned out that the filter materials were in excellent condition with no visible traces of clogging arising from soap.

The same results were obtained using the above-mentioned 3004-H19 aluminum alloy lubricant with residues of numerous oil types and amounts thereon.

EXAMPLE 2

Following the method described in Example 1, cans were drawn and smoothed using a lubricant similar to Example 1, except that the oleic acid was replaced with linoleic acid, isostearic acid and lauric acid, respectively. Similar results were obtained, with the exception of a slightly lower strength of the lubricant film.

EXAMPLE 3

To illustrate the use of a combination of emulsifiers, the following oil-based lubricants were mixed: 5 parts oleic acid 15 parts triethylene glycol caprate caprylate (CP Hall Plasticizer 4141) 4 parts polyoxyethylene lauryl ether (BriJ 30) 4 parts polyoxyethylene stearate ( Marry 45) 72 parts 1400 SSU mineral oil

A portion of the mixed lubricant having a viscosity of 400 SSU was emulsified using 1 part of pure oil for every 5 parts of deionized water. This part was used as the metal lubricant in a drawing press. Another portion of the pure oil-based lubricant was emulsified in a ratio of 1:10 between pure oil and deionized water and used as the metal lubricant in a smoothing press.

In both cases, it was found that the lubricant was sufficiently stable to allow 24 hours of operation (constant operation) without replacement of the lubricant due to interruption of operation. Of course, periodic additions were made in each case because of the discharge of the lubricant resulting from spills and residues

Claims (6)

8 14523 1 on the drawn and smoothed can. It was found that the lubricant gave rise to the formation of cans of superior quality to those made under similar conditions using conventional lubricants. Furthermore, the dispersion qualities of the lubricant proved to be excellent. P_a_t_e_n_t_k_r_a_v__: 1. Metalworking lubricant, which is dispersible in an aqueous medium, characterized in that it comprises per 100 parts of lubricant: a) between 2 and 8 parts of a monocarboxylic acid containing at least 12 carbon atoms; b) between 10 and 20 parts of an aliphatic carboxylic acid ester; c) between 2 and 10 parts of at least one emulsifier; and d) mineral oil available as the remaining number of parts. Lubricant according to claim 1, characterized in that the fatty acid has the formula cmH2m-n + l C00H> where m is an integer from 11 to 34 and where n is 0 or an even integer from 2 to 6. Lubricant according to claim 2, characterized in that m in the formula is an integer between 13 and 17 and that n is 0 or an even number from 2 to 4. Lubricant according to any one of the preceding claims, characterized in that the aliphatic carboxylic acid ester comprises an esterification product of a glycol which is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol or dipropylene glycol, and one or more aliphatic monocarboxylic acids containing 18 carbon atoms. Lubricant according to any one of the preceding claims, characterized in that the emulsifier comprises a nonionic, nonmetallic ester or ether of a monocarboxylic acid containing from 12 to 18 carbon atoms. Lubricant according to claim 5, characterized in that the emulsifier comprises the condensation product of ethylene oxide with an alcohol containing from 12 to 18 carbon atoms.