JPS62104898A - Water miscible lubricant for metal working - Google Patents

Abstract

Water-miscible metalworking lubricants containing formaldehyde-liberating compounds as biocides contain acidic organic phosphoric acid esters instead of conventional carboxylic acids in order to maintain prolonged biocide activity and also to reduce frothing upon dilution to aqueous emulsions or solutions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to water-miscible or water-soluble metalworking lubricants.

Water-based metalworking lubricants are a suitable medium for microorganisms and therefore, as emulsions and solutions, they must be protected against microbial attack, otherwise reducing the utilization and Toxicity problems may arise due to contamination of the lubricant.

So-called formaldehyde-releasing biocides have antimicrobial activity at low concentrations and are therefore widely used in this regard. However, the drawback is that metalworking lubricant concentrates have insufficient stability during storage, so that only a small portion of the original biocide is available when they are made into emulsions or solutions.

The amount of biocide obtained makes the biological stability of the emulsion or solution inadequate. The microbial stability of such emulsions or solutions is a decisive factor for their utilization and shelf life. The development of microorganisms in emulsions may result in considerable toxicity problems (rapid microbial growth, development of Escherichia coli with a risk of pathological transmission to humans) and a decrease in pH values (aqueous metal (increased corrosivity of the working lubricant) and incomplete breakage of the emulsion (eventually, as well as displacement of the existing emulsion and loss of the broken emulsion)
(resulting in inadequate mechanical efficiency and reduced useful life of tools)
becomes.

The rate of decomposition of biocides is dependent on the respective composition of the metalworking lubricant.

The present invention solves the problem by improving metalworking lubricants of this type in terms of microbial stability in order to suppress or prevent biocide degradation during storage of metalworking lubricant concentrates. I'm looking for.

According to the invention, there is provided a water-miscible metalworking lubricant comprising a mineral oil, an emulsifier, a solubilizer, a corrosion inhibitor, a biocide and an acid component, the acid component preferably being from 3 to 12% by weight of the composition. A lubricant is provided, wherein the lubricant is comprised of an acidic organophosphate ester, and the biocide comprises a formaldehyde-releasing compound.

Such compositions have the following composition in weight percent: Mineral oil 50 to 55 petroleum sulfonates 16 to 20 glycol ethers 12 to 16 boric acid amino esters 7 no LIO acid organophosphates
3 to 7 biocides 2 to 3
Preferably mineral oil 30 to 35 petroleum sulfonate 18 to 22 glycol ether
12 to 16 boric acid amino ester 5 to 8 fatty acid ester 5 to 8 chloroparaffin 8 to 12 acidic organophosphate ester 6 to 9 biocide 2 to 3 More preferably, mineral oil 2o to 3° nonionic emulsifier 10 to 15 boric acid amino ester
9 to 18 alkanolamines 0 to 7 glycol ethers 6 to 1220 robarafuin 16 to 20 water
5 to 15 acidic organic phosphate esters
7 to 12 Biocide 2 to 5 or mineral oil A to 25 Non-ionogenic emulsifier 10 to 15 Boric acid amino ester
12 to 18 alkanolamines 0 to 7 glycol ethers 6 to 20 corrosion inhibitors 10 to 15 water
5 to 20 acidic organic phosphate esters
5 to 10 biocide 2 to 5
has.

The composition according to the invention prolongs the inhibition of biocide degradation by replacing conventional carboxylic acids (particularly fatty acids) with acidic organophosphates. This significantly slower biocide degradation results in significantly better microbial resistance of the metalworking lubricant of the present invention after storage compared to conventional compositions.

A metalworking lubricant with this composition is an emulsion.

It has now become possible to demonstrate significantly improved foaming behavior in both bottles and solutions. From this point of view as well, it is important that the present composition contains no or only a small amount of carboxylic acid (particularly fatty acid) and instead contains an acidic organic phosphoric acid ester.

Conventional water-miscible metalworking lubricants for metal machinery contain biocides, primarily formaldehyde-releasing biocides, in concentrate for protection against microbial attack on the emulsion or solution during use.

These water-miscible metalworking lubricants also contain alkaline components (e.g. alkanolamines) and carboxylic acids (mainly fatty acids), which neutralize, lubricate, and, in part, emulsify and inhibit corrosion. fulfills the function of

Biocides, often selected by microbiological tests, are found to be good or at least suitable for working emulsions or solutions if they are made fresh or from concentrates that are stored only for short periods of time. Provides appropriate microbial resistance.

The biostability of working emulsions and solutions is determined by the biocide concentration required for microbial protection of working solutions or emulsions (minimum 5 is often unsatisfactory, or at least not completely sufficient, since the resistive concentration) is no longer useful.

The resulting amounts of biocides result in the disadvantages and problems described above.

Regarding the foaming tendency of conventional formulations (containing carboxylic acids), attempts have been made to suppress foaming by using skimmers (often containing silicone). However, such skimmers often become ineffective even after short use (because they adsorb and run off or their particle structure changes). Therefore,
There is a need for a metalworking lubricant that does not foam per se and does not require the use of a skimmer.

In developing the compositions of the present invention, biocides whose effective mechanism does not rely on the release of formaldehyde for antimicrobial action were also investigated. However, these formaldehyde-free biocides have the required broad range of activity (v!1
They were found to be free from all the bacteria, molds and yeasts normally occurring in mechanical emulsions) or to have unclear toxicological or ecological effects.

Furthermore, these formaldehyde-free biocides often cannot be included in concentrates.

Therefore, an attempt was made to determine whether the presence or absence of certain components affected the degradation rate of the biocide concerned by systematic changes in the composition of the concentrate.

The systematic variation of the composition of the concentrates made it possible to show that the rate of decomposition of the biocide during storage of the concentrates can be influenced in a certain range by the chemical composition of the f4 cotton material. The presence or absence of certain components can positively or negatively affect the rate of decomposition.

It has been specifically found that the inclusion of acidic organophosphate esters in the absence of carboxylic acids in metalworking lubricant formulations results in significant retardation of biocide degradation according to the present invention.

Furthermore, it has been possible to show that the complete or at least extensive replacement of carboxylic acids (particularly fatty acids) with acidic organophosphate esters can considerably reduce the foaming of emulsions and solutions.

Cooling lubricant formulations of this type are superior to conventional products in laboratory tests or under real conditions (even under complex situations such as high emulsion concentrations, and unfavorable conditions such as deep blind hole drilling). (below) has no tendency to foam (as an emulsion or solution).

Acidic organic phosphate esters are often used as corrosion-reducing components (extreme pressure components) in metalworking lubricants. However, the stabilizing effect of acidic organophosphates on formaldehyde-releasing biocides (inhibition of biocide decomposition during storage of concentrates) was previously unknown.On the contrary, phosphorus is an element necessary for microbial metabolism. It was considered that the phosphoric acid compound should not be included in terms of microbial growth (and this compound was therefore considered to be a drawback for the biostability of the lubricant).

Considerable foaming reduction for water-miscible metalworking lubricants is also expected.

For the improved foaming properties of the products described herein,
The carbones (particularly fatty acids) normally present in conventional compositions are at least substantially replaced by acidic organophosphate esters.

In order to achieve the improvements according to the invention (biocide degradation during storage/foaming biostability/inhibition), it is not sufficient to simply add an amount of acidic organophosphate to a conventional composition. be.

Particularly suitable acidic phosphate esters for use in the compositions of the invention are monoalkyl phosphates, dialkyl phosphates, monoisoalkyl phosphates, diisoalkyl phosphates, monoalkyl phosphates, dialkenyl phosphates, mono(alkylphenyl) phosphates. esters, di(alkylphenyl) phosphates, mono(isoalkylphenyl) phosphates, di(ynalkylphenyl)gJ acid esters, and mono- and dibolyether phosphoric esters, and the polyether groups may optionally be terminal groups such as alkyl, isoalkyl, Includes phenyl, alkylphenyl, and isoalkylphenyl and hydrogen.

(5 other people)

Claims (4)

[Claims] (1) A water-miscible metalworking lubricant comprising mineral oil, an emulsifier, a solubilizer, a corrosion inhibitor, a biocide, and an acid component, the lubricant comprising:
A lubricant characterized in that the acid component consists of an acidic organophosphate ester, preferably in an amount of 3 to 12% by weight of the composition, and the biocide consists of a formaldehyde-releasing compound. (2) having the following composition in weight percent: mineral oil 50 to 55 petroleum sulfonate 16 to 20 glycol ether 12 to 16 boric acid amino ester 7 to 10 acidic organophosphate ester 3 to 7 biocide 2 to 3 The water-miscible metalworking lubricant according to item 1. (3) The following composition in weight percent: Mineral oil 30 to 35 Petroleum sulfonate 18 to 22 Glycol ether 12 to 16 Boric acid amino ester 5 to 8 Fatty acid ester 5 to 8 Chloroparaffin 8 to 12 Acid organophosphate ester 6 to 9 Biocide 2 3. A water-miscible metalworking lubricant according to claim 1, having a composition of: (4) The following composition in weight percent: Mineral oil 20 to 30 Nonionic emulsifier 10 to 15 Boric acid amino ester 9 to 18 Alkanolamine 0 to 7 Glycol ether 6 to 12 Chloroparaffin 16 to 20 Water 5 to 15 Acidic organic phosphate ester A water-miscible metalworking lubricant according to claim 1, comprising 7 to 12 biocides and 2 to 5 biocides. 5) The following composition in weight percent: Mineral oil 5 to 25 Nonionic emulsifier 10 to 15 Boric acid amino ester 12 to 18 Alkanolamine 0 to 7 Glycol ether 6 to 20 Corrosion inhibitor 10 to 15 Water 5 to 20 Acidic organophosphate ester A water-miscible metalworking lubricant according to claim 1, having 5 to 10 biocides and 2 to 5 biocides. 6) The water-miscible metalworking lubricant according to any one of claims 1 to 5, which is in the form of an aqueous solution or an emulsion.