FI62680C - METALLBEARBETNINGSEMULSION - Google Patents

Description

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SS »C Patent oyCnr.eUy 10 C2 1933 (^ Patent raodde Iät ^ ^ (51) K» .Ht? / I «, a.3 C 10 M 1/06 FINLAND-FINLAND <*»> ftMnttlhtkMMM — Ntantamekntnf 790735 ( 22) H «k * mhpiWI - AnaMmlngadag 05-03-79" * (23) AJkupUvt — CMtlchatadaf 05-03-79 (41) Tullut JulklMkal - vests 08.09- 79 ^ • tant- oeh ragisteratyralMn ^ AmMun uthfToch ucUkrlfc · »ρ & ιμ 29-10.82 (32) (33) (31) Prytety * uo »l» ui — U | in <prior ** ° 7 · 03-76 Sweden-Sweden (SE) 7802533-5 (Tl) AB Karl Shams Oljefabriker, S-292 00 Karlshamn, Sweden-Sweden (SE) (7?) Sune Anälid, Karlshamn, Lennart Linden, Karlshamn, Sweden-Sweden (SE) (7I4) Berggren Oy Ab (5I +) Metalworking Emulsion - Metallbearbetningsemulsion

The present invention relates to an emulsion which has lubricating and cooling properties and which is intended for use in deforming metalworking, primarily in machining, but which is also suitable for pressing and rolling.

In machining metal machining, such as drilling, turning, milling, and grinding, mineral oil product-based cutting fluids are commonly used primarily because of the relative cheapness of the mineral oils. Most often, these are aqueous emulsions, and a wide variety of additives are also used to meet the requirements of the workshop industry, e.g., lubrication-enhancing EP additives (EP = Extreme Pressure).

As more attention has been paid to the working environment and occupational safety in recent years, interest in a new type of metalworking fluid has arisen. Mineral oil-based products cause oil mist and oil mist in the work area, as well as contamination in and around machines. Mineral oil and additives used can cause 62680 skin irritation, rash and allergies. Prolonged skin contact carries a risk of cancer, and inhalation of oily air carries a risk of lung damage. In recent years, information has been received from several parties on the presence of carcinogens in cutting fluids. Mineral oil contains polyaromatic hydrocarbons, e.g., benzpyrenes. In addition, due to the high temperatures in the cutting zone, it is likely that polyaromatics will be formed during use of the products.

Environmental legislation places great demands on the treatment of wastewater from the workshop industry. The cleaning technology for used emulsions and degreasing baths has become complicated as product development has brought with it more and more additives and more and more stable surfactant systems. As a result, the handling of used cutting fluids, primarily emulsions, has become cumbersome and expensive.

Smaller companies then have to use specialized disintegration companies, and only larger companies have their own emulsion disintegration plants, which, however, do not always work satisfactorily. The separation results in an aqueous phase that must be further treated in a conventional treatment plant and an oily sludge that must be disposed of or, at best, used as fuel. oil reuse is not possible.

The industry is therefore very interested in a new type of cutting fluid and is required to cause as little damage to people and the environment as possible. It produces as little oil smoke and oil mist as possible. It allows simple waste treatment without disposal problems. it withstands the attacks of microorganisms.

Fatty oils, i.e. vegetable or animal oils and fats, are functionally suitable raw materials for lubricants. They have been widely used in the past before cheaper mineral oils completely took over the market. Unlike mineral oils, fatty oils are renewable, environmentally friendly and biodegradable.

3,62680

In metal cutting machining, it is most often most advantageous to use a cutting fluid in the form of an aqueous emulsion of the oil-in-water type, whereby a better cooling effect is achieved while maintaining the lubricating power of the oil part. In addition, from an economic point of view, the use of an aqueous emulsion is considerably more advantageous.

Although these emulsions can be prepared in a ready-to-use condition, it is more suitable for transport and handling to first prepare a concentrate which can then be diluted with water at the user's premises, i.e. in the workshop industry.

Such a concentrated emulsion is required to have very good stability and at the same time to be easily and unrestrictedly dilutable with water and to be stable as an emulsion, even when diluted. In order to prepare such an emulsion, special emulsifiers (surfactant) must be used. In this case, strong synthetic tensides can be used, but due to the health and environmental problems mentioned at the beginning, these are avoided.

It is therefore an object of the present invention to provide a metal-working emulsion of the oil-in-water type based on triglyceride oils which meet the requirements for stability and dilutability and at the same time have sufficiently good and lubricating properties as those used in the environment but products harmful to health.

It has now surprisingly been found that starting from triglyceride oils, an emulsion which meets the requirements for stability and dilutability can be prepared by means of an emulsifier system consisting of fatty acid monoglycerides and alkaline soaps of fatty acids. By using only "natural" and completely harmless components, the environmental and health requirements of the product are met.

However, in order for the lubricating and cooling properties of the emulsion to be equivalent to those of mineral oil-based products, additional ingredients must be added.

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Thus, it has been found that the use of an organic amine such as an alkanolamine, e.g. triethanolamine or a fatty amine, considerably increases the wetting properties of the emulsion and thus its cooling effect. In addition, it has been found that the addition of free fatty acid to tri-glyceride oil improves its lubricating properties. In fact, the amine and the fatty acid are mainly present in the form of a salt, i.e. as a soap.

The invention is thus characterized in that the metalworking emulsion contains an oil phase and an aqueous phase and that the oil phase consists of 0.5 to 50 parts by weight of triglyceride oil, 0.1 to 10 parts by weight of fatty acid monoglyceride, 0.05 to 10 parts by weight of fatty acid and 05-10 parts by weight of an alkanolamine or a fatty amine are emulsified in an aqueous phase consisting of 0.05 to 3 parts by weight of alkaline soaps of fatty acids and 45 to 98 parts by weight of water.

Higher amounts of fat components are used in the preparation of emulsion concentrates, which, as stated above, are usually prepared by the manufacturer, while smaller amounts are used in the preparation of ready-to-use emulsions.

in the preparation of the oil phase, the fatty acid monoglyceride, fatty acid and amine are dissolved in triglyceride oil at a temperature of 40-70 ° C.

The aqueous phase is prepared by dissolving alkaline soaps at a temperature of 20-70 ° C, preferably 20-40 ° C.

The oil phase is slowly stirred into the aqueous phase at a temperature of 20-50 ° C.

In the preparation of ready-to-use emulsions, a stronger mixing is then sufficient to obtain a stable emulsion, whereas in the preparation of an emulsion concentrate, homogenization of the product is generally necessary. The homogenization is suitably carried out at a temperature of 40 to 60 ° C in a conventional homogenization apparatus.

Triglyceride oil can be any animal or vegetable oil or oil mixture that has a sufficiently low pour point to safely handle the emulsion in both concentrated and ready-to-use form, but which is also substantially free primarily of linolenic acid, which may otherwise cause oxidation. and polymerization problems. the oil must therefore preferably be flowable at room temperature and have an oleic acid content of at least 40%. From an operational point of view, particularly suitable oils are olive oil, peanut oil and lobster oil (rapeseed oil with a low erucic acid content). Bottom fractions of fractionated fats, such as "palmolein", have also proven to be excellent for this purpose.

The fatty acid monoglyceride must be of the "soft product", ie it must have a melting point below 60 ° C. The best product is pure oleic acid monoglyceride (mono-oleoglycerol), but other commercial products can also be used, such as Dimodan S, a molecularly distilled monoglyceride made by Grindstedvaerket, Denmark, from edible, purified lard with an approximate fatty acid composition of 30% palmitic acid. , 18% stearic acid and 40% oleic acid.

It is also possible to use the so-called. technical monoglycerides prepared by glycerolysis (glycerol esterification) e.g. from Lobra oil. Such products with a monoglyceride content of 40-60% are easy to manufacture without complicated equipment, so they are inexpensive. If such products are used, the ratio of triglyceride to diol glycerolysis product must, of course, be adjusted so that the monoglyceride content of the emulsion is correct.

the oil-soluble monoglyceride is used primarily because of its surfactant properties as a lipophilic component of the emulsifier system. However, the surface activity also brings with it a moisturizing effect, which improves the lubricating efficiency of the oil.

The fatty acid is suitably oleic acid. This component is subject to the same requirements as the oil and the monoglyceride, namely that it is flowable at room temperature, i.e. it has a titer lower than 25 ° C, and does not contain substantial amounts of more unsaturated homologues.

The fatty acid has been found to have a substantially increased lubricating effect. The presence of fatty acid prevents the formation of odor in the harder 6 62 680 machining steps, which can be expected in part due to the improvement in lubricating performance provided by the fatty acid and in part due to the formation of soaps from amine and fatty acid.

As the alkanolamine, an amine having 2 to 4 carbon atoms in the alkanol is suitably used. Particularly suitable is triethanolamine, which, in addition to its good moisturizing and anti-rust properties, has the advantage of its dermatological safety, as evidenced by its abundant use in cosmetic products.

The amine can also be based on a fatty feedstock, achieving the same good wetting and anti-rust properties. Suitably, a fatty amine having 8 to 18 carbon atoms in the chain can be used, and dodecylamine is considered particularly suitable.

The fatty acid soap is suitably composed of the sodium or potassium salt of a fatty acid (palmitic or stearic acid) having 12 to 22 carbon atoms, usually 16 or 18 carbon atoms. Potassium stearate gives a slightly better result than sodium stearate, but it is generally true that if stearin soaps are used, deionized water must be used to prevent the flocculation of calcium and magnesium soaps. This problem is completely avoided when using fatty acid soaps (sodium or potassium), as deionized water is most suitable for the preparation of the concentrate.

In machining steps with particularly high contact pressures, the lubricating properties of the metalworking emulsion can still be improved by the addition of lightly chlorinated and / or sulfurized triglyceride oils. These substances are well suited for the metalworking emulsion according to the invention. Preferably, 20-40% of the triglyceride oil is replaced by such substances in particularly demanding operations.

An antioxidant may be added to prevent oxidation and polymerization problems. Suitable antioxidants include butylated hydroxyanisole, BHA and butylated hydroxytoluene BHT. For example, Eastman Kodak products Tenox 2 or Tenox 6 can be advantageously used. These substances are suitably added to 0.1-1.0% by weight of the concentrated emulsion.

In unfavorable conditions in the workplace environment, 7 6? 680 toast microorganism attacks. If these microorganisms are allowed to develop freely over a relatively long period of time, an unpleasant odor may develop and at the same time the anti-corrosion properties of the emulsion deteriorate due to the formation of acidic decomposition products, as is the case with conventional mineral oil-based products. This is avoided by adding a bactericidal agent to the metalworking emulsion. Preferably, a formaldehyde blocking agent can be used, e.g. Grotan BK manufactured by Schulke &

Mayr GmbH.

The product according to the invention thus offers several advantages to the user:

The product is based entirely on fatty oils or their ingredients. These oils are renewable, environmentally friendly and biodegradable.

The presence of skin irritations, rashes and allergies can be substantially eliminated as well as the risk of cancer.

Due to the higher molecular weight of the triglyceride oils and the associated significantly higher vapor pressure, no harmful oil smoke is generated. In general, this means a much cleaner work environment.

Products based on fatty oils do not present any difficulties in terms of waste treatment. By choosing the right separation method, the greasy part can be easily separated, and the water part does not require special cleaning before removal. The fatty part can be hydrolytically cleaved by the prior art, in which case the recovered fatty acids can be reused.

The invention is further illustrated by the following examples:

Example 1 Preparation of a concentrated metalworking emulsion.

oil phase: 34.7 parts by weight of palmolein

4.9 parts by weight of monoglyceride, Dimodan S

2.7 parts by weight of rapeseed fatty acids 2.7 parts by weight of triethanolamine

Aqueous phase: 1.1 parts by weight of sodium oleate 55, C parts by weight of deionized water.

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Palmolein was formed from the bottom fraction of palm oil fractionation. The oleic acid content of palm olein was 50%.

the components of the oil phase were mixed at 60-70 ° C. The soap was dissolved in water at 25 ° C, after which the oil phase was slowly added to the aqueous phase with stirring. The dispersion thus obtained was then homogenized at 50 ° C in a conventional homogenizer.

The emulsion concentrate was easily and indefinitely dilutable with water of varying hardness (0.12 dH). Both the emulsion concentrate and the diluted emulsions proved to withstand storage without tendencies to oil separation.

The product was tested at a dilution of 1:10 in a multi-spindle drilling machine in production where the work step is threading to aluminum. After one month of use, the effect of the emulsion was unchanged and completely comparable to that of a conventional mineral oil-based emulsion.

Example 2

The metalworking emulsion was prepared for testing in a heavily loaded, numerically controlled automatic lathe. Machining took place with a carbide blade in several ferrous metals, such as cast iron and hardened tool steel. The metalworking emulsion was prepared as follows: Oil phase: 27.9 parts by weight of rapeseed oil 11.7 parts by weight of technical rapeseed oil monoglyceride 2.7 parts by weight of rapeseed fatty acid 2.7 parts by weight of triethanolamine 0.4 parts by weight of antioxidant, tenox 6 parts by weight: aqueous phase sodium oleate 55.0 parts by weight of deionized water.

Rapeseed oil was of the type with a low erucic acid content and an oleic acid content of 52%. The monoglyceride content of the technical monoglyceride was 40%.

The components of the oil phase were stirred at 40-50 ° C, and the sodium oleate was dissolved in water at 25-30 ° C. The oil phase was then added slowly and with stirring to the aqueous phase. The resulting dispersion was homogenized at 50 ° C in a conventional homogenizer.

The emulsion concentrate thus obtained was diluted 1:15 with ordinary tap water and tested on an automatic lathe. After three months of use, the performance of the metalworking emulsion was unchanged. The machined parts did not show any tendency to corrode. The metalworking emulsion did not cause drying coatings, but on the contrary, the cleaning of the machine surfaces was very easy.

Example 3

The purpose of the example is to demonstrate the lubricating-improving action of a fatty acid in an emulsion.

Two metalworking emulsions as a ready-to-use concentrate were prepared for testing in a rotary grinder. Metalworking emulsions were prepared from the following components: Sample A parts by weight Sample B parts by weight oil phase: oil phase: rapeseed oil 2.00 rapeseed oil 1.80 rapeseed oil technical «rapeseed oil technical Q -8 monoglyceride 'monoglyceride' triethanolazine 0.18 0.18

Aqueous phase: Aqueous phase: sodium stearate 0.10 sodium stearate 0.10 deionized water 97 deionized water 97

Rapeseed oil was of the type with a low erucic acid content and an oil-acid content of 60%. The monoglyceride content of the technical monoglyceride was 40%.

the components of the oil phase were mixed at 40-50 ° C and the sodium stearate was dissolved in the aqueous phase at 60-70 ° C. The oil phase was then slowly added to the aqueous phase with efficient stirring to give a stable emulsion.

Metalworking emulsions prepared in this way were tested in a rotary grinder for injection-hardened tool steel. In this case, 10 6 2 6 8 0 it was found that the smoothness of the machined surface and the relative wear of the grinding wheels showed that sample B (with fatty acid addition) gave better results than sample A (without fatty acid addition). On average, the surface smoothness was 10% better and the relative grinding wheel wear 30% lower in Sample B than in Sample A. The results were completely comparable to those obtained with conventional mineral oil-based emulsions without EP additive.

Example 4

The purpose of this example is to demonstrate the wetting effect of triethanolamine in an emulsion.

Two emulsion samples were prepared according to the same method as in Example 3.

Sample A part by weight Sample part B by weight Oil phase: oil phase: rapeseed oil 3.50 rapeseed oil 4.00 oleic acid monoglyceride 1.00 oleic acid monoglyceride * triethanolamine 0.10 Serium

Aqueous phase: Aqueous phase: sodium stearate 0.10 sodium stearate 0.10 deionized water 95 deionized water 95

Rapeseed oil was of the type with a low erucic acid content and an oil-acid content of 60%.

Measurements were performed on wetted steel surfaces of these emulsion samples. In this case, emulsion sample B (without triethanolamine) was found to give a wetting angle of 15-20 ° and emulsion sample A (without triethanolamine) gave a wetting angle of 15-20 °. This latter result was even slightly better than what is achieved with conventional mineral oil-based emulsions.

Example 5

The metalworking emulsion was prepared according to Example 1 from the following materials:

11 6? 6 8 O

oil phase: 34.3 parts by weight of palmolein

4.8 parts by weight of monoglyceride Dimodan S

2.7 parts by weight of rapeseed fatty acids 5.4 parts by weight of triethanolamine

Aqueous phase: 1.1 parts by weight of sodium oleate and 55.0 parts by weight of deionized water.

The cutting emulsion was studied for a long time in a numerically controlled tool machine used for paring and threading. The machine was used to machine rejuvenated hardened steel with a high-speed steel tool. The processing results were compared with those obtained using a conventional emulsion-type cutting fluid to which EP additives had been added. The traditional cutting fluid was specifically intended for heavy machining such as drilling, threading, thread cutting and drawing in various ferrous materials. Both cutting fluids were used at the same dilution, about 15 times, with plain tap water.

The smoothness of the surface of the treated material was the same for the conventional cutting fluid and the cutting fluid according to the invention. The tool life in drilling was as good and even slightly better in threading when using the cutting fluid according to the invention than when using a conventional cutting fluid.

Example 6 The purpose of this example is to show the improved lubricating effect of the metalworking emulsion according to the invention compared to the lubricating effect of cutting fluids of the conventional type.

A metalworking emulsion was prepared according to Example 1 from the following ingredients: oil phase: 34.3 parts by weight of palmolein 4.8 parts by weight of monoglyceride (Dimodan S) 2.7 parts by weight of rapeseed fatty acids 5.4 parts by weight of triethanolamine 6 2 6 8 0 12 aqueous phase: 1, 1 part by weight of sodium oleate 55.5 parts by weight of deionized water

The metal working emulsion was diluted 1:15 by volume with water and tested by drilling with a radial drill. The tool was made of high-speed steel and the material to be machined was hardened Mata-alloyed Ni-Cr-Motor steel. The lubricating effect of the metalworking emulsion was evaluated by measuring the torque of the bore, whereby a lower torque meant a better lubricating effect.

In the same experiment, the lubricating effects of several conventional surgical fluids were evaluated. Both mineral oil-based and non-mineral oil-based products were tested with and without EP additive (Cl and S compounds).

The results of the experiment are summarized in Table 1. As can be seen from Table 1, the metalworking emulsion according to the invention had a better lubricating effect than other types of cutting fluids.

Table 1:

Lubrication effects of various metalworking fluids as measured by torque. The metalworking fluid of the invention is fluid # 6.

Composition Torque

Liquid Type Pit. Miner. Grease Cl S Nm Better no.% Oil oil other

1 10 x x x x 11.31 5 2 6.7 x x xx 11.56 7 3 6.7 x x xx 11.55 6 4 semi-synthetic. 10 x 10.80 4 5 25 x 10.66 3 6 6.7 x 10.05. 1 7 10 x x 11.73 9 8. Synthetic 10 10.20 2 9 Water 11.69 8

Claims (10)

A metalworking emulsion of the oil-in-water type, having good stability and unlimited dilutability, based on triglyceride oils, the emulsion being intended for use in deforming metalworking, primarily cutting, but also suitable for pressing and rolling, characterized in that it consists of an oil phase dispersed in the continuous aqueous phase and that the oil phase consists of: 0.5 to 50 parts by weight of triglyceride oil, 0.1 to 10 parts by weight of fatty acid monoglyceride, 0.05 to 10 parts by weight of fatty acid, and 0.05 to 10 parts by weight of alkanolamine or a fatty amine, and that the aqueous phase consists of: 0.05 to 3 parts by weight of alkaline soaps of fatty acids, and 45 to 98 parts by weight of water. Metalworking emulsion in concentrated form according to Claim 1, characterized in that the oil phase consists of: 15 to 50 parts by weight of triglyceride oil, 2 to 10 parts by weight of fatty acid monoglyceride, 1 to 10 parts by weight of fatty acid, and 1 to 10 parts by weight of alkanolamine or fatty amine , and the aqueous phase consists of: 0.5 to 3 parts by weight of alkaline soaps of fatty acids, and 45 to 60 parts by weight of water. Metalworking emulsion according to Claim 1, in ready-to-use form, characterized in that the oil phase consists of: 0.5 to 10 parts by weight of triglyceride oil, 0.1 to 2 parts by weight of fatty acid monoglyceride, 0.05 to 2 parts by weight of fatty acid, and 0.05 to 1 part by weight. by weight of alkanolamine or fatty amine and the aqueous phase consists of: 0.05 to 0.5 parts by weight of alkaline soaps of fatty acids, and 90 to 98 parts by weight of water. Metalworking emulsion according to Claim 1, characterized in that the triglyceride oil is a fatty oil which is flowable at room temperature and has an oleic acid content (C18: 1) of at least 45% by weight, such as e.g. olive oil, peanut oil and low erucic acid rapeseed oil, and base fractions of fractionated fats such as palmolein or animal oleins. Metalworking emulsion according to Claim 1, characterized in that the fatty acids of the fatty acid monoglyceride are fatty acids having 16 and / or 18 carbon atoms, of which at least 40% by weight consists of oleic acid (C18: 1), preferably pure oleic acid monoglyceride. Metalworking emulsion according to Claim 1, characterized in that a technical product obtained by glycerol esterification of the triglyceride oil according to Claim 4 is used as the fatty acid monoglyceride. 6 2 6 8 0 13 Metalworking emulsion according to Claim 1, characterized in that the fatty acid titer is lower than 25 ° C and is preferably oleic acid. Metalworking emulsion according to Claim 1, characterized in that the alkanolamine is preferably triethanolamine or that the fatty amine is preferably dodecylamine. Metalworking emulsion according to Claim 1, characterized in that the fatty acid soaps are sodium or potassium soap of fatty acids with a titer of less than 25 ° C, and are preferably sodium or potassium oleate. Metalworking emulsion according to Claim 1, characterized in that optionally 20 to 40% by weight of the triglyceride oil is replaced by a substance for high contact pressure, which substance is a lightly chlorinated or sulfurized triglyceride oil.