CA1223243A

CA1223243A - Soluble oil cutting fluid

Info

Publication number: CA1223243A
Application number: CA000450069A
Authority: CA
Inventors: Anthony P. Rawlinson; James White
Original assignee: BP PLC
Current assignee: BP PLC
Priority date: 1983-03-23
Filing date: 1984-03-21
Publication date: 1987-06-23
Also published as: EP0120665A3; EP0120665B1; DK163284A; DK163284D0; AU558608B2; ATE27174T1; GB8307975D0; ZA842146B; AU2586784A; DE3463673D1; EP0120665A2

Abstract

ABSTRACT OF THE DISCLOSURE

SOLUBLE-OIL CUTTING FLUID

A soluble-oil, suitable when diluted with water, for use as a cutting fluid comprises an alkali or alkaline-earth metal alkyl benzene sulphonate, a fatty acid diethanolamide, a mixed alkanolamine borate, a polyisobutenesuccinimide and a major proportion of mineral oil. The soluble-oil is relatively stable without the need for a conventional coupling agent and some soluble-oil emulsions are bio-static even though conventional biocides are not included.

Description

5452 (2) ~223;2~3 SOLUBLE-OIL CUTTING FLUID

This invention relates to a soluble-oil and to an oil-in-water emulsion containing the soluble-oil, which emulsion is suitable for use as a gutting fluid Soluble-oil emulsions are well known as cutting fluids. The term "soluble-oil" although used throughout the industry it, in fact, a misnomer because the constituents are not soluble in water. The soluble-oils are basically mineral oils blended with emulsifiers and other additives which, when added to water and stirred, form an oil-in-water emulsion. The emulsion allows the good cooling properties of water to be utilized in the metal working process whilst the oil and additives provide lubrication and corrosion inhibiting properties The one or more emulsifiers included in the soluble-oil may not readily form a stable blend with the mineral oil and so a coupling agent is commonly required to bind the emulsifier to the oil, Conventional coupling agents include, for example, volatile alcohols such as sec. buttonhole bottle oxitol or cyclohexanol. The volatility of these coupling agents means that over a period of time coupling agent is lost from the soluble-oil by vaporization This loss of coupling agent reduces the stability of the soluble-oil and is often associated with an objectionable smell. Further, the coupling agents have relatively low flash points which means that great care just be taken when they are blended or otherwise handled.
The present invention relates to a soluble oil which is relatively stable without the need for a conventional coupling agent.
Thus according to the present invention a soluble-oil suitable, ~L~Z3~2~3 when diluted with water, for use as a cutting fluid comprises an alkali or alkaline-earth metal alkyd Bunsen sulphonate, a fatty acid diethanolamide, A mixed alkanolamine borate, a polyisobutene-succinlmide and a major proportion of mineral oil.
Soluble-oil emulsions may become contaminated by bacteria, yeasts and molds The growth of these microorganisms may cause problems such as emulsion breakdown, the production of slimes and finagle mats and the evolution of foul odors. Besides are often therefore included in soluble-oil formulations to control microbial growth. It lo has surprisingly been found that at least some of the soluble-oils according to the present invention are bio-static even though conventional besides are not included in the formulation.
Suitably, the soluble-oil according to the present invention comprises the following amounts of the components;
EYE Amount (I o total White) Alkali or Alkaline-earth metal alkyd Bunsen sulphonate 2 - 10 Fatty acid diethanolamide 2 - 3 Mixed alkanolamine borate 2 - 5 20 Polyisobutenesuccinimide 2 - 6 Mineral Oil balance The alkali metal or alkaline-earth metal of the alkyd Bunsen sulphonate is preferably potassium or calcium or more preferably sodium. The alkyd group is preferably derived from polypropylene.
The alkali or alkaline-earth metal alkyd Bunsen sulphonate may be produced by known methods from synthetic ~ulphonic acids. Preferably the molecular weight of the compound is from 400 to 520. high molecular weight improves the corrosion inhibiting properties of the soluble oil whereas a low molecular weight improves emulsion stability and so the choice of molecular weight involves a compromise. Mixtures of alkyd Bunsen sulphonates may be used.
The fatty acid diethanolamides are preferably formed by the reaction of diethanolamine with naturally occurring fatty acids having from 12 to 20 carbon atoms. The fatty acids may be saturated or unsaturated but are preferably unsaturated.

~2~Z~3 The mixed alkanolamlne borate comprises the reaction products of more than one alkanolamine with boric acid. The alkanolamines may be selected from monoethanolamine, diethanolamine, triethanolamine, NUN dim ethyl ethanol amine. A preferred combination of alkanolamines 5 it moo- and di-ethanolamine.
The polyisobutenesuccinimide is preferably over based with excess amine and preferably has a molecular weight of from 1000 to 3000.
The soluble-oil formulation also preferably contains a small amount of distilled water e.g. from 0 to 2% by weight of the total weight of the soluble-oil. The distilled water improves the stability of the blend.
A deforming agent such as a Friedel Rafts wax may also be included in the soluble oil. A suitable wax is SICILY wax SO 105 supplied by Weber. The amount of deforming agent is preferably in the range 0-0.05% by weight of the total weight of the soluble-oil.
The soluble-oils according to the present invention may also contain other conventional additives for soluble-oils such as for example corrosion inhibiting additives. A suitable commercially available corrosion inhibitor comprises a solution of Bunsen sulfonamide Huxley carboxylic acid in water and N,N-dimethyl amino propel amine. This commercially available corrosion inhibitor is particularly effective when supplemented with triethanolamine.
Alternatively, a mixture of triethanolamine and other carboxylic acids such as, for example, caprylic acid or caprice acid may be used to inhibit corrosion. Typically, the corrosion inhibitor is used up to an amount of 2% by weight of the total weight of the soluble-oil, I
the corrosion inhibitor comprises a mixture of triethanolamine and a carboxylic acid then the two compounds may be present in equal weights up to a combined weight of 2% of the total weight of the soluble-oil.
If a biocidal soluble-oil is required, a conventional buzzed may be included in the formulation.
It is to be understood that the optional components of the soluble-oil are included in the composition in place of some of the mineral oil.
Although a wide range of mineral oils Jay be used in the soluble--I tide marl 3

2 243 oil formulations according to the present invention, base oils design Ed 100 to 500 solvent neutral have been found to be particularly suitable, Leo paraffinic oils typically having kinematic viscosities at 40C in the range 12 to 100 cyst.
The soluble-oil according to the present invention it relatively stable and when mixed with water readily forms an emulsion which may be used in a number of metal working operations e.g. cutting, drilling and grinding. Preferably, the emulsion has a water to soluble-oil ratio of from 10:1 to 40:1 although higher and lower dilutions may be useful in certain applications.
The invention is illustrated with reference to the following example.
Example 1 Two soluble-oil formulations were prepared by mixing the 15 following components:-Component Amount (% by weight) Formulation A Formulation B
Sodium alkyd Bunsen sulphonate 6.25 6.25 (sold by Paramins under the trade name 20 Synacto 416) Fatty acid diethanolamide 2.5 2.5 (sold by Unichema under the trade name Prichem~1859) Mixed alkanolamine borate 2.5 2.5 (sold by Hiawatha Chemicals under the designation MOB) 30 Polyisobutenesuccinimide (sold by Laboriously under the designation L 5602 2.5 2.5 Sicily wax SO 105 - 0.01 (supplied by Weber) Distilled Water 1.0 Paraffinic Base Oil 86.25 85.24 The sodium alkyd Bunsen sulphonate had an average molecular weight of 440 and was used as a 60~ by weight solution on a paraffinic mineral oil. The fatty acid diethanolamine was oleic acid trudge aureole ~2~Z~3 diethanolamide and was approximately 25% over based with excess diethanolamine. The mixed alkanolamine borate was a mixture of boric acid, monoethanolamine and diethanolamine in the approximate weight ratio 30:33:35, The polyisobutene succinimide was formed by the reaction between a polyisobutene having a molecular weight of approximately 1000,succinic acid android and diethanolamine and was over based with a small excess of NUN dim ethyl ethanol amine.
The thermal stability of each formulation was tested after 14 days at temperatures in the range -5C to 50C using a method based Oil the Institute of Petroleum test method IT 311, Thermal Stability of Emulsifiable Cutting Oil. Both formulations were very viscous at temperatures of 0C and below but were stable on warming. Formulation B was also stable at temperatures up to 50C. Formulation A became unstable at temperatures above 40C. However, in the presence of 0.5%
wit of water, Formulation A was also stable up to 50C.
Samples of the two formulations were mixed with mains tap water at ratios of water to oil of from 10:1 to 25:1. The oil readily emulsified in the water at each dilution and each emulsion was subjected to the Institute of Petroleum standard test method IT 125 Aqueous Cutting Fluid Corrosion of Cast Iron. There was no visible staining or pitting at the lower dilutions and the corrosion at the highest dilutions was hardly perceptible.
The propensity to foam of Formulation B was less than that of Formulation A as determined by the Institute of Petroleum standard test method IT 312, Frothing Characteristics of Emulsifiable Cutting Oil. This is presumably due to the inclusion in Formulation B of Sicily wax, a known deforming agent.
A test rig was used to evaluate the microbial degradation of the soluble-oil emulsions in a simulated workshop operation. The rig comprised a reservoir for the cutting fluid and an air lift pump to transfer the fluid from the reservoir to a funnel containing metal cuttings, the funnel being mounted over the reservoir so that the fluid drained back into the reservoir. Duplicate samples of Formulation A diluted with mains tap water in the ratio of water to oil of 20:1 were tested in the test rig. An inoculum prepared from a ~232~3 mixed culture of fungi and bacteria originating from a spoiled cutting oil emulsion was added to the test samples so that an initial total viable count of approximately 106 micro-organisms per milliliter of emulsion was obtained. Air was passed through the rig to circulate and aerate the fluid during normal working hours from Monday to Friday each week. Each Monday morning, viable counts of aerobic bacteria, yeasts and mounds were prepared and the presence of sulfide producing bacteria, evolution of HIS, pal and emulsion stability were determined.
Up to the end of 14 weeks, the emulsion had not evolved HIS or encouraged yeast, mound or finagle growth. The total viable bacteria count remained at approximately 106 organisms per milliliter of emulsion throughout the test. The strength of the emulsion was relatively constant throughout the test and the pi which was initially 9.5 fell to around I after 12 days and then remained at this value for the remainder of the test period.
The results show that Formulation A, which contains no conventional buzzed or coupling agent, forms a stable emulsion which has biostatic properties and does not evolve HIS.

~3;~3 Example 2 Two soluble-oil formulations were prepared by mixing the following components:-Amount I by weight) Formulation C Formulation D
Sodium alkyd Bunsen sulphonate 9 5 9.5 tSynacto 416, ox Paramins) Fatty acid diethanolamide 2.5 2.5 10 (Prichem 1859, ox Unichema) Mixed alkanolamine borate 2.5 2.5 (MOB 12* ox Hiawatha Chemicals) 15 Pol~isobutenesuccinimide 5.0 5.0 (L 5602~ ox Laboriously) Arylsulphonamidocarboxylic acid in - 1.0 water and amine (Hostacor Ho sold by ~1oechst) Triethanolamine - 1.0 Sicily wax So 105 0.01 0.01 (supplied by Weber) Distilled Water 2.0 2.0 Paraffinic Base Oil 78.49 76.49 Formulation D is similar to Formulation C except that it contains a corrosion inhibiting mixture comprising triethanolamine and Hostacor H. Hostacor H is a commercially available corrosion inhibitor comprising a solution of Bunsen sulfonamide Huxley carboxylic acid in water and N,N-dimethyl amino propel amino The thermal stability of each formulation was tested after 14 days at temperatures in the range O to 60C using a method based on the Institute of Petroleum test method IP311, Thermal Stability of Emulsifiable Cutting Oil. Both formulations were stable throughout the temperature range.
Each of the formulations were mixed with mains tap water at ratios of water to soluble-oil of from 10:1 to 40:1. The soluble-oils readily emulsified in the water at each dilution. Each of the emulsions was subjected to the Institute of petroleum standard test method IP125, Aqueous Cutting Fluid Corrosion of Cast Iron.
Formulation C showed no pitting or staining up to dilutions of 20:1 Trudy and Formulation D showed no pitting or staining up to dilutions of 40:1.
The results show that both formulations, which contain no convention Ed coupling agent, form relatively stable emulsions with water and that the inclusion of the triethanolamine and Hostacor H
improve the corrosion inhibiting properties of the soluble-oil.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A soluble-oil suitable, when diluted with water, for use as a cutting fluid comprises as a corrosion inhibitor and emulsion stabiliser an alkali or alkaline-earth metal alkyl benzene sulphonate, as a corrosion inhibitor, a fatty acid diethanolamide, as a corrosion inhibitor, a mixed alkanolamine borate, as a dispersant a polyisobutenesuccinimide and a major proportion of mineral oil.

2. A soluble-oil as claimed in claim 1 comprising the following proportion of the components as percentages of the total weight of the soluble oil:-Alkali or alkaline-earth metal alkyl benzene sulphonate 2-10%
Fatty acid diethanolamide 2- 3%
Mixed alkanolamine borate 2- 5%
Polyisobutenesuccinimide 2- 6%
Mineral Oil balance

3. A soluble-oil as claimed in claim 1 in which the alkali or alkaline-earth metal alkyl benzene sulphonate has a molecular weight of from 400 to 520, the alkali metal or alkaline-earth metal is selected from the group comprising sodium, potassium and calcium and the alkyl group is derived from polypropylene.

4. A soluble-oil as claimed in claim 1 in which the fatty acid diethanolamide is the reaction product of diethanolamine with a naturally occurring fatty acid having from 12 to 20 carbon atoms.

5. A soluble-oil as claimed in claim 1 in which the mixed alkanolamine borate is the reaction product of boric acid and at least two alkanolamines selected from the group comprising monoethanolamine, diethanolamine, triethanolamine and N,N dimethyl ethanolamine.

6. A soluble-oil as claimed in claim 5 in which the alkanolamines are mono- and di-ethanolamine.

7. A soluble-oil as claimed in claim 1 in which the polyisobutenesuccinimide is overbased with excess amine and has a molecular weight of from 1000 to 3000.

8. A soluble-oil as claimed in claim 1 which contains up to 2% of distilled water by weight of the total weight of the soluble-oil.

9. A soluble-oil as claimed in claim 1 which contains up to 0.05% of a defoaming agent by weight of the total weight of the soluble oil.

10. An emulsions suitable for use as a cutting fluid comprising water and a soluble-oil as claimed in claim 1 in a volumetric ratio of 10:1 to 40:1.