DE708331C - Cutting oils - Google Patents

Description

The invention relates to mineral oil emulsions such as those used in the metalworking industry for cutting and grinding. B. can be used by gears, tools, crank pins, ball bearings, pump cylinders. The aim of the invention is to prevent or delay the foaming of these mineral oil preparations during use. These emulsions usually consist of a mineral oil, an emulsifying agent and water. The mineral oil can be a light petroleum lubricating oil fraction, a spindle oil, a white oil, or the like. Crude oil distillates from paraffinic or naphthenic oils having viscosities between 1.85 and 5.7 E ⁰ ° E at 38 ⁰ C are generally useful. Naphthenates or sulfopates of alkalis or nitrogen bases, i.e. Na-

trium, potassium, onium salts come to use ao. Organic naphthenates, such as those of diethanolamine or triethanolamine, can also be used. In general it is good to use mixtures of naphthenates and sulfonates e.g. B. to use in a ratio of 1: 4. It was found that the naphthenates promote the foaming of the emulsions very strongly during use, and they are more water-soluble than the sulfonates. The emulsifying agent may constitute 5 to 4O ° / ₀ of the mineral oil.

It is with the use of such emulsions in mechanical metalworking a known fact that significant amounts of foam are formed as a result of the inevitable agitation of the emulsion, which not only disrupt the mechanical work, but also collection and storage vessels,

which serve to take up or keep the emulsion ready to overflow.

Various proposals have already been made with regard to the foaming ability to suppress these mineral oil emulsions. A common method is to use it a somewhat unstable emulsion that contains free oil. Up to a certain Grade free oil has a foam-suppressing effect.

To this way of working has the problem that with prolonged use it becomes unstable Emulsions tend to disintegrate completely.

Another suggestion recommended the addition of stearic acid or aluminum stearate to the water-soluble oils. But even this path is not feasible because this Additives with available free or by hydrolysis from sodium sulfonates or Naphthenates formed alkali soaps, which lead to oil formation or to the solidification of the soluble oils, which is particularly troublesome.

The present invention now discloses a new way, the propensity of the water-soluble to suppress foaming oils.

It has been found that waxes contain acids with more than 22 carbon atoms in the molecule, the 5 to 50 per cent. of such acids Contained in the free state, have the ability to foam the water-soluble suppress oils. The most suitable wax of this type is the montan wax, however

synthetic waxy products, such as CP and Z wax (cf. E. J. Fischer »Waxes, wax-like substances and technical wax mixtures ”1934, pp. 48 to 57), as well Wool wax useful for the invention. The waxes are made in the water soluble oils Amounts of 0.001 to 0.5 percent by weight are added. The additional amount must not be used in any Fall so large that the wax precipitates at ordinary temperature. Appropriate is to heat the water-soluble oil to the melting temperature of the wax and then to distribute the wax in it by stirring vigorously. Overheating of the Avoid oil.

These waxes are particularly effective in suppressing foam formation in the case of the water-soluble ones oils in which naphthenates are used as emulsifiers.

It should be noted that this effect is not disturbed if the water-soluble oil nor dyes, antioxidants, thickener polymers, or resins other additives customary for mineral oils are made. To the technical effect to show the invention, on the one hand, a soluble oil that z. B. a mixture of Containing sulfonates and naphthenate soap as emulsifiers, mixed with 40 parts of water. A other part of the soluble oil is mixed with about 0.01% montan wax and divided into 40 parts Water emulsified. Both emulsions were made using the Mixmaster whisk processed.

The following figures were obtained:

Mix master foam sample

10 minutes with 700 tours
per minute 500 cc sample Coincide
of the foam in (1) Emulsion with no additive
(2) emulsion + 0.01 ° / ₀
Montan wax Foaming
in percent by volume 20 minutes
ι to 2 seconds 160
0

In another attempt, the

Checked the effect of differently sized additives of the same wax. Was used the surgical wax of the trade (I. G. Farben-

Industrie A.-G.). The samples were carried out again as described above. It turned out the following numbers:

Emulsion without additives

Emulsion + 0.005% surgical wax
Emulsion + 0.010% surgical wax
Emulsion + 0.02 ° / ₀ OP Wax

Foaming
in percent by volume

160

70
40

Coincide
. of the foam
in minutes

The results show that even additions of ο, οΐ ° / ₀ montan wax and 0.02 ° / ₀ OP wax considerably reduce the tendency to foam formation in emulsion water-soluble oils.

Two more typical examples of mixtures according to the invention are given below are given.

No. ι

I2, oo ° / o sodium sulfonate, 3.00 ° / ₀ Naphthenic 0.50 _^0/0 sodium hydroxide, 0.50 ° / ₀ alcohol, 2.00 ° / o water, 0.05 ° / ₀ montan wax, 81, 95 ° / ₀ paraffin oil.

No. 2 I2, oo ° / ₀ sodium sulfonate,

4.60 ° / ₀ resin,

0.50% sodium hydroxide, 0.50 ° / ₀ alcohol, 2, oo ° / o water,

0.05% montan wax, 80.35% paraffin oil.

Opposite the octyl alcohol, which is also proposed as a foam suppressor the waxes used according to the invention have the advantage that they are non-volatile. Of the Octyl alcohol is very unpleasant when used as a defoaming agent Fume off. In addition, octyl alcohol is much more expensive than montan wax, which is of course also of great importance with such a mixture.

Claims (1)

Claim: Use of ester waxes whose acids have at least 22 carbon atoms contained in the molecule and which contain at least 5% free acid, such as montan wax, as a foam-preventing additive to alkali sulfonates or naphthenates containing hydrocarbon emulsions (so-called. Water-soluble oils), the Amount of ester wax added 0.001 to 0.5% of the water-soluble oil amounts to.