CS212712B2 - Emulsion for metal machining processes - Google Patents

Abstract

The emulsion is of the oil-in-water type, the oil phase comprising, by weight: 0.5 - 50 parts of triglyceride oil, 0.1 - 10 parts of fatty acid monoglyceride, 0.05 - 10 parts of fatty acid, and 0.05 - 10 parts of alkanolamine or fatty amine, and the water phase comprising, by weight: 0.05 - 3 parts of an alkali metal soap of a fatty acid, and 45 - 98 parts of water. The emulsion is used in machining to remove metal, deep drawing and rolling.

Description

The present invention relates to an emulsion having lubricating and cooling properties which are intended for use in the deformation treatment of metals, in particular. for - chip machining, but - also suitable for stamping and rolling.

In - chip-machining - such as - - is - drilling, turning, milling, threading - and grinding - - usually - - use cutting '·' fluids based on products - from - - mineral - oils / in particular - due to the - relative - grace - of the mineral oils, - in most cases - they consist of aqueous emulsions - and to satisfy the requirements -. metalworking. Many additives, such as pressure-resistant additives, are added to the industry to increase lubrication. In the last - - years - - has been paying - - increased attention - to the working. - environment - - and - - occupational safety, - and that - created - - interest - - in - new types - - fluids for · - machining - metals. Unsatisfactory - working environment - and - ^: associated ^: - health - problems are general - problems - of - products that are used in the metalworking - - industry today -. ; . v. .--. · -; i,

- Mineral oil-based products cause - oil smoke and 'oil mist' - in the working areas, - as well as - as they contaminate the machines - and - the environment - of the machines. - Mineral - oil - and used - additives - can cause irritation - - skin · - eczema and - allergic - reactions. There is a risk of cancer with prolonged action. . ' / .a. /. ·.

skin and - risk of - lung damage - by inhalation of - oily smoke - and - oil mist. - - Recently - there are several. reports on the presence of carcinogenic substances. - in cutting materials. liquids. Mineral - - oils - contain polyaromatic hydrocarbons - eg - benzpyrenes. Due to the - high - temperatures in the cutting zone, it is also likely that. polyaromatic compounds are formed when these articles are used.

Legislation · - environmental control - lays down - demanding requirements - for handling - waste - water - in the metalworking industry; - - - Technology - - Cleaning ^-: waste emulsions and degreasing - bath - a - complicated, because 'development - - Product - .vede - - to- use other - ^and: others. additive - and more stable - emulsifying systems; This led to - to - torna; - the - treatment - of waste - cutting - - liquids, - especially emulsions - has become - very - difficult and - expensive.

Smaller - companies must benefit. specialized ^: destructive businesses - and only the largest - companies have - - their own - departments on - - - shredding - emulsions ^; which - however - do not always work safely ^; - and - satisfactorily. - e-. mulch leads to ^: - the aqueous phase that must - be. - further - in conventional - treatment facilities, - and - to sludge, - which. it contains - oil which must - be - stored,. - or, at best, usable as fuel. . Oil reuse is not taken into account.

As a result, industry is very interested in a new type of coolant and the requirements for such a coolant are considerable:

- have minimal harmful effects on humans and the environment, - produce very little oil 'smoke and oil mist, - allow easy treatment of waste without disposal problems, - have no complicated composition and have few additives, - be resistant to attack microorganisms.

Fatty oils, that is, vegetable or animal oils, and fats are functionally suitable raw materials for lubricants and have been widely used before cheaper mineral oils have completely dominated the market. Unlike mineral oils, fatty oils are renewable, environmentally friendly and can be completely biodegraded.

For cutting or grinding metals it is most advantageous to use a cutting fluid in the form of a water containing oil-in-water emulsion with which it is applied. achieves a better cooling effect while maintaining the lubricating effect of the oil portion. From an economic point of view, an aqueous emulsion is considerably more advantageous.

These 'emulsions. ·.' may be prepared in an appropriate state. for direct use, but from a transport and handling point of view it is preferable first. to prepare a concentrate which may sooner or later be diluted with water by a user in the metalworking industry.

The requirements for these concentrated emulsions are such that they have very good stability and stability. to be easily and indefinitely diluted with water. and stable in the form of an emulsion, even when diluted. In order to produce such emulsions, special emulsifiers (surfactants) must be used, but strong synthetic surfactants may be used, but due to the health and environmental problems mentioned in the introduction, they should be used. these substances should be eliminated.

It is an object of the present invention to provide an oil-in-water metal-working emulsion based on tri-glyceride oils which are sufficiently stable and can be diluted indefinitely and which at the same time have sufficiently good lubricating properties as compared to the products used to date. undesirable environmental and health aspects.

Now it has surprisingly turned out that when it comes out of. triglyceride oils, an emulsion can be prepared which satisfies the requirements of stability and dilutability by means of. emulsifying system containing 'monoglycerides.' fatty acids and alkaline soaps. of fatty acids. By using only 'natural' and completely harmless ingredients, the environmental requirements of the product are met.

In order to lubricate. and cooling properties. emulsions have been brought to the level of mineral oil product properties. additional ingredients should be added.

The use of an organic amine such as an alkanolamine, for example triethanolamine or a fatty amine, has been shown to greatly increase the wetting properties of the emulsion and thereby its cooling effect. Furthermore, the addition of free fatty acid to the glyceride oil has been shown to increase its lubricating properties. In fact, they are amine and fatty. the acid is particularly present in the form of salts, that is, as a soap.

SUMMARY OF THE INVENTION The present invention is based on an oil-in-water treatment emulsion with good stability and unrestricted dilutability, based on triglyceric oils, which is intended for deformation treatment of metals, in particular by machining, but also suitable for pressing and rolling. continuous aqueous phase. The oil phase is formed, expressed. % by weight of the total emulsion

0.5 to 50% by weight of liquid triglycerin oil containing at least 45% oleic acid,

0.1 to 10% by weight of a monoglyceride of a fatty acid having 16 and / or 18 carbon atoms, of which at least 40% is oleic acid,

From 0.05 to 10% by weight of a fatty acid having from 16 to 22 carbon atoms;

0.05 to 10% by weight of a C8-C18 alkanolamine or aliphatic amine.

The aqueous phase is formed

0.05 to 3% by weight of alkali soaps of fatty acids having from 16 to 18 carbon atoms and up to 98% by weight of water.

Larger amounts of fatty components are used in the preparation of emulsion concentrates that would be. previously mentioned, they are usually prepared by the manufacturer and minor amounts are used in the preparation of ready-to-use emulsions.

When the oil phase is prepared, the fatty acid monoglyceride, the fatty acid, and the amine are dissolved in the triglyceride oil at a temperature of 40 to 70 ° C. The aqueous phase is prepared by dissolving the alkaline soaps at. temperature in the range 20. to 70 ° C, preferably 20 to 70 ° C. Deň: 32 ° C.

The oily phase is slowly added to the aqueous phase, with stirring, at a temperature in the range of 20 to 50 ° C.

For the preparation of suitable emulsions. for direct use it is necessary to mix sufficiently intensively to:. a stable emulsion is obtained,. whereas for homogenizing the emulsion concentrate, homogenization of the product is usually required. Homogenization is preferably carried out. at temperature. in the range of 40 to 60 ° C in a conventional homogenizer.

The triglyceride oil may be any animal or vegetable oil or oil blend having a freezing point sufficiently low to allow convenient handling of the emulsion in the. concentrated state as well as in a suitable state. for direct use, but which is. at the same time free of linolenic acid in particular to avoid oxidation and polymerization difficulties. The oil should therefore preferably be liquid at room temperature and should have an oleic acid content of at least 40%. Particularly suitable oils from a functional point of view are olive oil, peanut oil, and oil. (Low orucic rapeseed oil). The low melting fractions of fractionated Шкдг, such as "palmolein", are excellent for this purpose.

The monoglyceride of the fatty acid was to be of the -type type. "Soft product" means that it should have a melting point below 60 ° C. The best product is pure oleic acid monoglyceride (monooleoglycerol) but also other commercial products such as Dimodan S, a molecularly distilled monoglyceride from edible refined pork lard containing approximately 30% palmitic acid, 18% stearic acid and 40% acid may also be used. oil.

It is also possible to use so-called technical monoglycerides produced by glycerolysis (glycerolesterification), for example lobra-oils. These products containing 40 to 60% monoglyceride are easy to manufacture without complicated equipment and therefore interesting. However, if these products are used, the ratio between the triglyceride oil and the glycerolysis product must be adjusted so that the monoglyceride content of the emulsion is correct.

. The oil-soluble aminoglyceride is used primarily as a lipophilic component of the emulsifier system due to its surface-active properties. The surface activity also imparts a wetting effect which enhances the lubricating effect of the oil.

The fatty acid is preferably oleic acid. The requirements for this component are the same as for oil and monoglyceride to be liquid at room temperature, i.e. to have a titer lower than; 25 ° C and did not contain substantial amounts of unsaturated homologs.

The fatty acid has been shown to increase substantially the lubricating effect. The presence of a fatty acid prevents the formation of odor in more demanding machining operations, which is a ruler of a fatty acid, and in part this may be likely to be dependent on an increase in lubricating damage with the formation of amine and fatty acid soaps.

The alkanolamine is preferably an amine having two to four carbon atoms in the alkanol moiety. Particularly suitable is triethanolamine, which has equally good wetting and anti-rust properties, also has the advantage of being dermatologically innocuous, as is also evident from its widespread use in cosmetic products.

In the same way, higher aliphatic amines can also be used, whereby equally good wetting and anti-rust properties can also be achieved. Preferably, a C8-C18 fatty amine can be used, and dodecylamine is particularly preferred.

The fatty acid soap is preferably a sodium or potassium salt of a C 12 to C 22 fatty acid, usually of 16 or 18 carbon atoms (palmitic or stearic acid). Potassium stearate gives somewhat better results than sodium stearate, but if stear soaps are to be used, deiohized water must be used; to prevent flocculation of calcium and magnesium soaps. When oleic acid (sodium or potassium) soaps are used, this problem is completely eliminated, although deionized water is well used when producing a concentrate. ,.

In metalworking operations at very high contact pressure, the lubricating properties of the metal working emulsion can be further enhanced if necessary by the addition of a slightly chlorinated and / or sulfurized triglyceride oil. These components are very well compatible with the metal working emulsion of the invention. Preferably, 20 to 40% of the triglyceride oil is replaced by these components in extremely difficult operations.

Alternatively, an antioxidant may be added to avoid oxidation and polymerization problems. Suitable antioxidants are butylhydroxyanisole, BHA, and butylhydroxytoluene, BHT. Commercial products are suitably added from 0.1 to 1.0% to a concentrated emulsion.

Under adverse conditions, microorganisms can easily attack. If these microorganisms are allowed to develop indefinitely for an extended period of time, an unpleasant odor may develop as well. the corrosion inhibitory properties of the emulsion may be reduced by the formation of acidic breakdown products in the same way as is the case with traditional mineral oil products. This is avoided by adding a bacterial growth-inhibiting agent to the metal working emulsion. Formaldehyde releasing agents may be used.

. Thus, the product produced according to the invention provides a long number of advantages for the user:

The product is entirely based on fatty oils or their components. These oils can be regenerated, which is environmentally friendly and biodegradable.

The incidence of skin irritation, eczema and allergic reactions can be greatly reduced and the risk of cancer can be excluded.

Due to the higher molecular weight of the triglyceride oils and the associated considerably higher vapor pressure, difficult oil smoke is not produced. This generally means a significantly cleaner working environment.

Products based on fatty oils do not cause any problems in terms of waste treatment. With proper separation technology, the oily phase can be easily separated and the remaining water does not require any special cleaning * before discharge. The fatty phase can be readily cleaved by hydrolysis by known methods, and the fatty acids obtained can be reused. : c! · <

The invention is further elucidated by the following examples:

Example 1

Preparation of an emulsion for working metals in concentrated form

Oil phase:

34.7% by weight of "palmoleins"

4.9% by weight of monoglyceride (Dimodan - S) as specified in the description

2.7% by weight of rapeseed fatty acids. oil (C16 to G22) 2.7 wt% triethanolamine

Aqueous phase:

1.1% by weight, sodium oleate 55.0% by weight, deionized water "Palmoletn" was a low melting fraction of palm oil. The oleic acid content of 'paimolein' was 50%. The oil phase components were mixed at 60-70 ° C. The soap was dissolved in water at 25 ° C, then the oil phase was added slowly to the aqueous phase with stirring. The dispersion thus obtained was then homogenized at 50 ° C in a conventional type homogenizer.

The emulsion concentrate could be diluted with water of different hardness (0 to 12 dH) easily and indefinitely. Both the emulsion concentrate and the diluted emulsions were stable during storage without tendency to oil separation. ý

The product was tested at a 1: 10 dilution on a multi-spindle drill in a production where the threading operation was aluminum. After one month of operation, the emulsion function did not change and was completely comparable to the emulsion function based on conventional mineral oils.

Example 2

The metal working emulsion was prepared for testing on very loaded numerically controlled automatic lathes. Many ferrous metals, such as cast iron and hardened tool steel, were machined with a carbide tip. The metal working emulsion was prepared as follows:

Oil phase:

27,9% by weight of 'rapeseed oil'

11.7% by weight of technical rapeseed oil monoglyceride

2, -7%, by weight, of rapeseed fatty acids

2.7 wt% triethanolamine

0.4% by weight, commercial antloxidant

Aqueous phase:

1.1% by weight, sodium oleate and 55.0% by weight; deionized water

The rapeseed oil was low; erucic acid and oleic acid 52%. Technical; the monoglyceride had a content of 40% of the actual monoglyceride.

The components in the oil phase were mixed at 40-50 ° C. The oil phase was then slowly added to the aqueous phase at 25-30 ° C with stirring. The dispersion obtained was homogenized at 50 ° C in a conventional homogenizer.

The emulsion concentrate obtained in this manner was diluted ^1: 15 with tap water and tested on an automatic lathe. After 3 months of operation, the metal working emulsion is unchanged. The treated parts showed no corrosion tendencies. The metal-working emulsion did not produce coatings after drying, on the contrary, the machine surfaces were very easily kept clean.

Example 3

The example is intended to illustrate the increased lubricating effect caused by a fatty acid in an emulsion.

Two ready-to-use metal concentration emulsions were prepared for testing on a round grinding machine. Metal working emulsions were prepared from the following components:

Sample A

Oil phase rapeseed oil technically rapeseed monoglyceride triethanolamine

Aqueous phase:

sodium stearate deionized water

Sample В

Oilseed: rapeseed oil 'technical monoglycer id Of rapeseed oil ^:

2.0 wt.

0.78% wt.

0.18% wt.

0.10 wt.

% wt.

1.80% wt.

0.78% by weight, 'fatty acids zřepkového pleje (C16-C22) 0.20% triethanolamine ^0.18:%! wt.

Aqueous phase: sodium stearate 0.10 wt%, deionized water 97 wt%.

Rapeseed oil was a low erucic acid oil with an oleic acid content of 60%. The technical monoglyceride had a content of 40% of the actual monoglyceride.

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

The metal working emulsions prepared in this way were tested in a round grinding machine by hardening tool steel. Sample B (with fatty acid addition) was found to give better results than Sample A (without fatty acid addition) in terms of surface quality of the material as well as relative wear of the grinding wheel. and the relative wear of the grinding wheel was 30% lower with Sample B than with Sample A. The results were quite comparable to those obtained using conventional mineral oil emulsions without pressure-resistant additives.

Example 4

This example is intended to elucidate the enhanced wetting function of the emulsion by adding triethanolamine.

Two emulsion samples were prepared in the same manner as in Example 3.

Sample A

Oil phase:

rapeseed oil oleic acid monoglyceride triethanolamine 3.50% 1.00% 0,50% wt. wt. wt. Aqueous phase: sodium stearate 0,10% wt. deionized water 95% wt. Sample B Oil phase: rapeseed oil 4.0% wt. acid monoglyceride oil 1.0 ° / о ^! wt. Aqueous phase: sodium stearate 0,10% wt. deionized water 95% wt.

Rapeseed oil had a low erucic acid content with an oleic acid content of 60%.

The wetting capacity of these emulsions was measured on steel surfaces. The emulsion of sample B (without triethanolamine) was found to have a contact angle of 40 to 45 ° and the emulsion of sample A (with triethanolamine) had a contact angle of 15 to 20 °. This second result was even somewhat better than that obtained with conventional mineral oil emulsions.

Example 5

The metal working emulsion of Example 1 was prepared with the following components:

Oil phase:

34.3% by weight of "palmolein"

4.8 wt% monoglyceride

2.7% by weight of rapeseed oil fatty acids (C16-C22)

5.4% by weight of triethanolamine

Aqueous phase:

1.1% by weight, sodium oleate 55.0% by weight, deionized water

The metal working emulsion has been tested for a long time on a numerically controlled machine tool for drilling and tapping. Hardened steel was machined with high-speed tools on the machine tool. The machining results were compared with those obtained using a conventional emulsion type cutting fluid with pressure-resistant additives. Conventional cutting fluid has been especially designed for heavy machining such as drilling, threading and deep drawing of various ferrous materials. Both cutting fluids were used at the same dilution about 15 times with ordinary tap water.

The surface smoothness of the machined parts was the same for the conventional cutting fluid and the cutting fluid of the present invention. The tool life was equally good for drilling and even slightly better for threading than conventional cutting fluid.

Example 6

The example is intended to illustrate the increased lubricating effect of a metal working emulsion according to the invention by comparison with the lubricating effect of conventional types of cutting fluids.

The metal working emulsion was prepared in the same manner as in Example 1 using the following components:

Oil phase:

34.3 masses, parts of "palmolein"

4.8 parts by weight of monoglyceride

2.7 parts by weight of rapeseed oil fatty acids (C16 to C22);

5.4 parts by weight of triethanolamine.

Aqueous phase:

1.1 parts by weight of sodium oleate 55.0 parts by weight of deionized water

The metal working emulsion was diluted in a volume ratio of 1: 15 with ordinary tap water and tested on a radial drill. The tools were high speed steel and the workpiece material was low nickel, chromium and molybdenum steel. The lubricating effect of the metal working emulsion was determined by measuring the torque during drilling, with lower torque values indicating a better lubricating effect.

The lubricating effect of several conventional cutting fluids was also evaluated in the same way. The measurements were made on products based on n, and mineral and non-mineral oils, with and without pressure-resistant additives (Cl- and S-compounds).

The results of the measurements are summarized in the table

It is clear from the table that the metal working emulsion of the invention showed a better lubricating effect than the other types of cutting fluids. Fluid No. 6 is a metal machining fluid of the present invention.

Table 1

Lubricating effect of various metal working fluids, measured by drilling torque

Liquid 'no. 'Type conc. ° / o 'min. oil Composition ointment. oil Cl with Krout. mom. when drilling order 1 '10' X X X X 11.31 5 2 6.7 1 X X X X 11.56 7 3 1 6,7 ' X X X X 11.55 6 4 polosynt. '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 synthet. '10 10.20 2 9 water 11.69 8

OBJECT OF THE INVENTION

Claims (9)

1. Triglyceride oil based oil-in-water emulsion with good stability and unlimited solubility, intended for deformation of metals mainly by machining, but also suitable for pressing and rolling, characterized in that it contains an oil phase which is dispersed in the continuous aqueous phase and the oil phase is formed by weight percent. in the total emulsion, 0.5 to 50% by weight of a liquid triglyceride oil containing at least 45% oleic acid, 0.1 to 10% by weight of a monoglyceride of a fatty acid having 16 and / or 18 carbon atoms, of which at least 40% is oleic acid, 0.05 to 10% by weight of a C16 -C22 fatty acid; and 0.05 to 10. % by weight of an alkanolamine or an aliphatic amine of 8 to 18 carbon atoms, the aqueous phase consisting of 0.05 to 3 percent by weight of C16 -C18 alkali soaps; 45 to 98 weight percent water. 2. An emulsion for working metal according to item 1 in concentrated form, characterized in that the oil phase is formed 15 to 50 weight percent triglyceride oil 2 to 10 weight percent of a monoglyceride of a fatty acid, 1 to 10% by weight of fatty acid and 1 to 10% by weight of alkanolamine or an aliphatic amine and the aqueous phase consists of 0.05 to 3% by weight of alkali soaps of fatty acids; and 45 to 60 weight percent water. 3. The metal-working emulsion of claim 1 in a form suitable for use, characterized in that the oil phase consists of: 0.5 to 10 weight percent triglyceride oil 0.1 to 2% by weight of a monoglyceride of a fatty acid, 0.05 to 2 weight percent fatty acid 1.05 to 1% by weight of alkanolamine or aliphatic amine and the aqueous phase is formed 0.05 to 0.5% by weight of alkali soaps of fatty acids; and 90 to 98 weight percent water. 4. The metal-working emulsion of claim 1, wherein the triglyceride oil is a fatty oil, liquid at room temperature and having an oleic acid content of at least 45% by weight, such as olive oil, peanut oil and low erucic acid rapeseed oil; the lowest melting fraction of fractionated fats such as palmolein or animal oleins. 5. The metal-working emulsion of claim 1, wherein the fatty acids in the fatty acid monoglyceride are fatty acids having 16 and / or 18 carbon atoms, at least 40% by weight of which is oleic acid, with mono-glyceride of oleic acid being preferred. 6. The metal-working emulsion of claim 1, wherein the fatty acid monoglyceride is a technical product obtained by esterifying triglyceride oil with glycerin. 7. The metal-working emulsion of claim 1, wherein the fatty acid has a titer of less than 25 [deg.] C. and is preferably oleic acid. 8. The metal-working emulsion of claim 1, wherein the alkanolamine is triethanolamine and the aliphatic amine is dodecylamine. 9. The metal-working emulsion of claim 1, wherein the alkaline fatty acid soaps are sodium or potassium fatty acid soaps with a titer below 25 [deg.] C. and is preferably sodium or potassium oleate.