AU628454B2

AU628454B2 - Synthetic metalworking fluid

Info

Publication number: AU628454B2
Application number: AU47136/89A
Authority: AU
Inventors: Joann Adele Quitmeyer
Original assignee: WR Grace and Co Conn; WR Grace and Co
Current assignee: WR Grace and Co Conn
Priority date: 1988-12-21
Filing date: 1989-12-20
Publication date: 1992-09-17
Anticipated expiration: 2009-12-20
Also published as: JPH02225595A; CA2005682A1; EP0375412A1; AU4713689A

Description

628 415

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: i, Ii *i I 1 I P I K.

It 8414 *i iC 41 i 0 i.

o #4 Applicant(s): W.R. Grace Co.-Conn.

1114 Avenue of the Americas, New York, New York, 10036, UNITED STATES OF AMERICA Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: SYNTHETIC METALWORKING FLUID Our Ref 157850 POF Code: 90766/90766 The following statement is a full description of this invention, including oa.I the best method of performing it known to applicant(s): o 1- 6006 P18/7/78 PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia 11 1-1-o SYNTHETIC METALWORKING FLUID 0 00 o 0 0 0 0 0000 "o o o "a 00 0 00 S0 0 0 00 0 0 0 u 0 00 0 0 00 0 0o 0 u 0* 04, This application is a continuation-in-part of U.S.

Application Ser. No. 287,963, filed 12/21/88.

The present invention relates to metalworking fluids and more particularly a synthetic metalworking fluid which provides excellent lubrication and cooling for both hard and soft metals and is relatively bioresistant.

BACKGROUND OF THE INVENTION In most industrial metal working operations, a metalworking fluid is employed. Metalworking fluids act both as a coolant to maintain the temperature of the metal surfaces within a desired range and as a lubricant to lubricate the interface of the tool and metal. The cooling effect of the metalworking fluid adds considerable life to the cutting tools, such as drill bits, metal formers, etc., and also tends to prevent the warping or distortion of the metal. The lubricating properties, on the other hand, reduce the friction between the cutting tool and the metal, thereby reducing the power requirement of the machinery.

There are four types of metalworking fluids: straight oils, soluble oils, semi-synthetics and synthetics.

Straight oils, which include mineral and vegetable oils, provide excellent lubricating properties but only minimal cooling. Soluble oils, i. emulsions of oil in water, provide both lubricity and cooling, and perform well on both hard metals, such as titanium and steel, and soft metals, such as aluminum. However, soluble oils are usually subject to rapid biodegradation and impaired lubricity after repeated use. Semi-synthetics, ie. water solutions with smaller amounts of oil microemulsified, and synthetics, i.e.

I -i 4 I 1 4 t iI r .44 4 4 44 4 4 II 4 48 4t 4 4 I(

I

non-petroleum based emulsions or solutions provide improved lubricity and cooling, can be filtered, and can generally be used for much longer periods of time than soluble oils.

However, neither synthetics nor semi-synthetics, free of chlorine, sulfur or phosphorous, have been successfully used on difficult machining operations, e.g. tapping of both hard and soft metals. Prior art synthetics have used chlorine, sulfur or phosphorus as extreme pressure additives in order to machine hard metals. These additives create a hazard to the environment, and chlorine can cause hydrogen embrittlement (stress cracking). Also, when cutting different metals it has been necessary to change metalworking fluids during the manufacturing process, increasing production time and causing disposal problems.

Soluble oils containing chlorine, sulfur or phosphorous extreme pressure additives have been used when a manufacturing process requires the working of two or more metals of significantly different hardnesses. However, soluble oils have several drawbacks. First, a single soluble oil may not be suitable for all metals in severe deformation processes such as tapping. Secondly, soluble oils have a typical useful life of 2-3 weeks, whereas synthetic fluids may be used for 12 months or more. Also, soluble oils present a disposal problem due to their petroleum base. If chlorine is present, an even greater disposal problem exists.

The present invention provides a synthetic fluid, free of chlorine, sulfur and phosphorous, without the shortcomings of soluble oils, which may be used as a metalworking fluid when working two or more metals of different hardnesses. The metalworking fluid of the present 2 h.- -3invention provides good lubrication and cooling to both hard and soft metals, allowing a single fluid to be used for both types of metal even in severe applications.

The present invention relates to a metalworking fluid containing a polybutene such as an isobutylene-butene copolymer or polyisobutylene; and a polyether glycol having a carboxylate functionality. In one preferred embodiment, the polybutene is a copolymer composed of 95-100% by weight mono-olefins and 0-5% by weight isoparaffins. The metalworking fluid may or may not be diluted with water to form a micro-emulsion.

One embodiment of the present invention is to provide oo Ji a metalworking fluid comprised of an isobutylene-butene Scopolymer, a polyether glycol having a carboxylate functionality, a corrosion inhibitor and a defoamer.

S0o A range of compositions may be prepared in accordance with the invention.

In a further embodiment the invention provides a 0 water dilutable, micro-emulsion metalworking fluid comprising :6 from about 2 to about 50 parts by weight of an isobutylene-butene copolymer or polyisobutylene, and from about 2 to about 50 parts by weight of a polyether glycol having a carboxylate functionality.

The present invention in another embodiment provides a metalworking fluid comprised of a blend of an isobutylenebutene copolymer, or polyisobutylene, a polyether glycol having a carboxylate functionality and an emulsifier, the blend being diluted in a volume of water such that the blend comprises from about 0% to about 95% by volume of the total volume of blend and water.

Another metalworking fluid of the invention comprises an emulsifiable blend of from about 2 to about 50 parts by 39,,-,eight of an isobutylene-butene copolymer, composed of about -4- 95-100% by weight of one or more mono-olefins and about by weight of one or more isoparaffins; from about 2 to about parts by weight of a polyether glycol having a carboxylate functionality; and from about 5 to about 160 parts by weight of one or more emulsifiers.

An additional embodiment of the invention provides a metalworking fluid comprising from about 2 to about 50 parts by weight of a polybutene and from about 2 to about 50 parts by weight of a polyether glycol having a carboxylate functionality.

The present invention also provides a metalworking process comprising the steps of forming a metalworking fluid o^ of an isobutylene-butene copolymer or polyisobutylene; and a V polyether glycol having a carboxylate functionality, applying :the metalworking fluid to a metal to be worked and working the metal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS pThe present invention overcomes the shortcomings of prior metalworking fluids by providing a synthetic metalworking fluid which is useful in working both hard and soft metals.

6 0: The metalworking fluid of the present invention contains two major constituents, a polybutene selected from the group consisting of isobutylene-butene copolymers and polyisobutylenes, to provide the lubricity needed for working soft metals, and a polyether glycol having a carboxylate functionality as an extreme pressure additive for working hard metals. It has been found that this synergistic blend may be used to machine both hard and soft metals. The blend also unexpectedly provides lubricity superior to that obtained when polybutenes are used alone, and extreme pressure properties 3/ 3 9, 11111 0 00 Or gi 00 O 0 000040 I a 0 00 320 ao o o 0 6 00 i 9 i superior to those obtained when polyether glycols are used alone. One or more emulsifiers may be added to the polybutene and the polyether glycol when the concentrate is to be emulsified in water. Other common metalworking fluid constituents may also be added, if desired.

*a i/ The fluid is made in concentrate (neat) form, i without the addition of water. The fluid may be used in its neat form or it may be diluted to a lesser concentration with water, if so desired.

The concentrate will preferably have a pH of from about 8 to about 10.5, more preferably from about 8.5 to about The isobutylene-butene copolymer used in one PrCe.r-ckl/ embodiment of the present invention is composed of about to 100% by weight mono-olefins and about 0% to 5% by weight isoparaffins. Mono-olefins are a class of unsaturated aliphatic hydrocarbons with one double bond, obtained by cracking petroleum fractions at high temperatures.

Isoparaffins are a class of aliphatic hydrocarbons characterized by a straight or branched carbon chain, and have the generic formula C NH2n+2 Various grades of such a copolymer are commercially available fron the Amoco S,00 Corporation and are sold under the tradename INDOPOL®. Any of 0 0 0 these grades may be used in the present invention, but 00oo: preferably those with a viscosity less than 5000 SUS (measured S at 100 0

F).

o 00 o4l One example of a suitable isobutylene-butene copolymer has an average molecular weight of 563, a viscosity of 2441 SUS at 100 0 F, and a flash point of 141 0 C, and is sold under the tradename "Amoco Polybutene H-15". The amount of 0 copolymer used in the present invention can range from about 1 "o oS part by weight to about 50 parts by weight. Preferably, the amount used is from about 2 parts by weight to about 36 parts by weight.

o6 The term polybutene refers to either a polyisobutylene which is essentially pure, or the isobutylene-butene copolymer described above which may contain up to about 5% of other polymers, such as l-butene and 2-butene. The isobutylene-butene copolymer is preferred, as it is less susceptible to crystallization at low temperatures, but similar properties can be obtained using the 99+% polyisobutylene. Mixtures of polyisobutylene and the isobutylene-butene copolymer may also be used.

The isobutylene-butene copolymer, or polyisobutylene, is desired because it provides the lubricity needed to obtain a good surface finish on soft metals such as aluminum.

The second constituent of the metalworking fluid is a polyether glycol having a carboxylate functionality. The polyether glycol having this structure provides additional lubricating properties to the metalworking fluid, and acts as an extreme pressure additive which reduces tool wear when S, machining hard metals such as titanium. Thus it is possible to machine hard metals without the use of traditional "'ri chlorine, sulfur or phosphorus extreme pressure additives, eliminating the hydrogen embrittlement and disposal problems caused by these additives. Suitable polyether glycols are commercially available from the Olin Corporation, under the trademark, POLY-GO.

0oes One example of a suitable polyether glycol is the 0 0 0 proprietary polyoxyalkylene glycol sold by O.in Corporation 0° under the tradename POLY-G® MLB-10X. This polyoxyalkylene t glycol has a viscosity of 587 SUS (at 100 0 F) and a specific gravity of 1.066 at 25°C. The carboxylate functionality of Sthis polyoxyalkylene glycol is acidic in nature.

7 The amount of polyether glycol used in the present invention can range from about 2 parts by weight to about parts by weight. Preferably, the amount used is from about parts by weight to about 36 parts by weight.

A third constituent of the metalworking fluid, if desired, may be one or more emulsifiers. Any oil-in-water emulsifier may be used in the invention, alone or in combination with other emulsifiers.

Examples of suitable emulsifiers that may be used in the present invention include but are not limited to tall oil fatty acids, petroleum sulfonates, fatty acid amines, fatty acid alkanolamides and nonionic, cationic, anionic or amphoteric surfactants.

The selected emulsifiers should completely emulsify the other constituents of the concentrate when mixed with water. The emulsifiers should also be capable of maintaining a stable emulsion during use.

The amount of emulsifier used in the concentrate is Sgenerally from about 5 parts by weight to about 160 parts by weight.

o0 Other conventional metalworking fluid additives may ooo be added so long as they do not adversely affect the emulsion stability or lubricity of the fluid. Such additives include corrosion inhibitors, defoamers, biocides, surfactants, o azeotropes, colorants or dyes and pH buffering agents.

CC Examples of suitable corrosion inhibitors include, •t but are not limited to, amine carboxylates and amine borate esters. Other suitable corrosion inhibitors would be obvious to one skilled in the art and are commercially available.

8 The amount of corrosion inhibitor is generally from about .1 part by weight to about 20 parts by weight, and preferably from about .1 parts by weight to about 15 parts by weight in the concentrate.

Suitable defoamers may be used in the present invention. Such defoamers are generally proprietary products and are known only by their commercial trade names. Suitable, preferably organic, defoamers for use in the present invention include TROYKYD® D666, a proprietary blend available from Troy Chemical, and Foam Ban MS-455 from Ultra Additives. Other suitable defoamers would be obvious to one skilled in the art.

The amount of defoamer is generally from about 0.25 parts by weight to about 10 parts by weight, and preferably from about 0.5 parts by weight to about 5 parts by weight.

The concentrate may be formed in any conventional manner such as adding all of the ingredients simultaneously and mixing them until a completely blended liquid is formed.

However, it is preferred to first add the isobutylene-butene copolymer, or polyisobutylene, to a large mixer, then slowly 4 COG..: add the one or more emulsifiers and then the corrosion oe°, inhibiting agent and polyether glycol, mixing well after each 0.WO addition. Lastly, any other ingredients such as a defoamer and dye are added and thoroughly mixed into a homogeneous, stable blend. If desired, small amounts of water, may be °GO° added subsequent to mixing. The concentrate is then decanted S into containers for storage and shipment.

The metalworking fluid may be used in its neat form ie. as a concentrate or it may be diluted -c ey--mpe -O+ Coo+ cAn A--r +4o wy £ew s c~ 'kJe&.

4 it1 t «9 Preferably, the metalworking fluid is diluted with water such that the amount of concentrate is from about 1% to by volume of the total volume of the water and concentrate. However, in applications where water cannot be tolerated, a 100% solids concentrate can be used.

For example, where lubricity properties are most desired, less water is used so that there is more concentrate present. When cooling properties are most desired, the volume of water is greater than the volume of concentrate.

Generally, where lubricity is primarily required, the amount of water used is about 50% by total volume. Where cooling is primarily required, the amount of water is from about 80% to 99% by total volume.

The metalworking fluid is useful on a variety of metals including but not limited to steel, iron, aluminum, copper, titanium, nickel and alloys thereof.

EXAMPLE 1 A metalworking fluid concentrate of the following formula was mixed together: 4.5 parts by weight of an isobutylene-butene copolymer; parts by weight of a tall oil fatty acid low rosin emulsifier; 12.6 parts by weight of a petroleum sulfonate fatty acid amine blend emulsifier; 8.3 parts by weight of a fatty acid alkanolamide emulsifier; 7.5 parts by weight of polyoxyalkylene glycol, Olin Chemicals POLY-G® o 0 o o 0 o So 0 0 00 0 0 B o o o0o oo S 00 0 00 0 000 0000 0 004 o B a 0 0 0 o ««a 0 00 ct 0 00 0 0 4 t t( 10

I

I 0 o 0 o 0 00 0o o 0o oo.

0 0 O 00 0so0 0 0 0 n a a 0 I o t 0 00 c ci 0.1 parts by weight parts by weight inhibitor; of a surfactant; of an amine carboxylate corrosion of an amine borate ester of a sodium salt of tolyltriazole 1.3 parts by weight corrosion inhibitor; parts by weight corrosion inhibitor; 0.2 parts by weight parts by weight parts by weight parts by weight part by weight of of of of of a citrus fragrance; a glycol ether; a biocide; triethanolamine; a defoamer, Troy Chemicals Troykyd® D666; 0.5 of a second defoamer, Foam Ban MS-455 from Ultra Additives and, 0.06 part by weight of a blue dye.

51.0 deionized water (optional).

The fluid of Example 1 was used to machine hydraulic valve bodies from 2024 and 356 cast aluminums and titanium using a carbide tool. A straight oil was used side by side with the fluid of Example 1 for comparison. Results were as follows: Coolant Type Concentration Sump Life Parts/Tool Milling Reaming Drilling Speed (SFM) Milling Reaming Drilling Finish (RMS) Reaming Straight Oil 100% 2 Months 500 135 200 60 30 100 20-30 Fluid of Example 1 11% concentration in water 4 Months 1000+ 475+ 900+ 600 490 600-800 8-16 11 The metalworking fluid of Example 1 was usable for more than twice as long as the straight oil. This is due both to the greater thermal stability of the fluid of Example 1 and to its reduced susceptibility to contamination by metal fines. The number of parts which could be machined with a given tool was greatly increased. Higher speeds were also obtainable and the surface finish was improved.

While this invention has been discussed in the light of its preferred embodiments, e, as a metalworking fluid for the cutting of hard and soft metals, it is by no means meant to be so limited. The metalworking fluid of this invention may be used in any metalworking operation where its properties would be useful. Examples of such metalworking operations include but are not limited to tapping, grinding, milling and forming.

Further, while this invention has been described with reference to its preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art tand it is intended to cover in the appended claims all such *0 modifications and equivalents as fall within the true spirit ooo and scope of this invention.

2 0 2402P 12

Claims

1. A metalworking fluid for the cutting of both hard and soft metals and that is free of chlorine, sulphur or phosphorus extreme pressure additives and that comprises a polybutene selected from isobutylene-butene copolymers and polyisobutylenes, a polyether glycol having a carboxylate functionality and, optionally, one or more emulsifiers.

2. A fluid according to claim 1 wherein the polybutene is an isobutylene-butene copolymer, composed of 95-100% by weight of one or more mono-olefins and 0-5% by weight of one or more isoparaffins.

3. A fluid according to claim 1 or claim 2 wherein the polybutene is essentially all polyisobutylene. o o 0

4. A fluid according to any preceding claim wherein the 0 polyether glycol is a polyoxyalkylene glycol. 0 1 A fluid according to claim 4 wherein the polyoxyalkylene glycol has acidic carboxylic functionality.

I

6. A fluid according to any preceding claim wherein the amount of polybutene is from 2 to 50 parts by weight, the amount of polyether glycol is from 2 to 50 parts by weight, and the amount of emulsifier is from 5 to 160 parts by weight, wherein the fluid is an emulsifiable blend and includes 1 to parts by weight of one or more corrosion inhibitors and to 15 parts by weight of defoamer.

7. A fluid according to claim 6 wherein the emulsifier is selected from sulfonates, non-ionic, cationic, amphoteric and anionic surfactants, and is preferably a fatty acid alkanolamide.

8. A fluid according to any preceding claim having pH 8 to 10.5. cZ.^ssswa -14-

9. A fluid according to any preceding claim and that includes emulsifier and includes water in an amount of from 1% to 99% by volume of the total volume.

10. A fluid according to claim 9 wherein the water is in an amount in the range of from 50 to 90% by volume of the total volume.

11. A metalworking process comprising applying a metalworking fluid defined according to any one of claims 1 to to the surface of a metal and working the metal.

12. A metalworking process according to claim 11 wherein the metal is selected from the group consisting of steel, iron, aluminium, copper, titanium, nickel and alloys thereof. o

13. A metalworking fluid according to any one of claims 1 to 10 substantially as herein described with reference to the Example. DATED: 19 June 1992 PHILLIPS ORMONDE FITZPATRICK l Attorneys for: W R GRACE CO -CONN 0541S 0