CS240507B1 - Antimicrobial stabilized cutting lubricant for application on metallic materials - Google Patents

Abstract

Stabilized emulsion or oil solution is intended for application to metallic materials especially in engineering and metallurgy. It contains 0.01 to 1.0 wt. synergistic a stabilizing composition consisting of 10 to 25 wt. formaldehyde, 30-75 ° C wt. alkanolamine C2 to C8 preferably monoethanol amine, 0.1 to 5 wt. nitrite sodium or potassium; propanediol containing at least one molecule in the molecule; one of Br, J, NO, NO 2, 1 to 5 wt. di- or triethanolamine and the remainder % to 100 wt. it forms water and falls water-soluble polyethoxamer-based surfactant aliphatic or aromatic substances containing hydrogen.

Description

BACKGROUND OF THE INVENTION The present invention relates to an antimicrobilane-stabilized poly-component machining fluid for application to metallic materials with synergistic effect.

When machining in mechanical engineering, various machining fluids are used. Most widely used and used are aqueous solutions and aqueous emulsions containing 0.5 to 10 wt. emulsifying oils and other additives. The widespread use of these machining fluids brings new problems in terms of occupational hygiene and occupational health. Machining fluids, however, also provide a suitable environment and conditions for the growth of a variety of microorganisms. Microbiological strains that are most commonly found in machining fluids and which reproduce very rapidly in distribution systems and reservoirs include Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Candida albicans. In practice, this means that the primary chemical risk due to the chemical composition of the liquid is compounded by the biological risk. The reproduction of micro-organisms in the organism, and thus the devaluation of the machining liquid under favorable conditions, occurs already in the first to third weeks, thus deteriorating its hygienic and technological properties. In particular, the risk of skin and infectious diseases is increased by contact or inhalation, the working environment deteriorates due to an unpleasant odor, and the stability of the emulsion liquid by degradation of the emulsifier, and thus the lubricating and cooling effects, deteriorates. Finally, corrosion protection is degraded by degradation of the emulsifier, corrosion inhibitors and lowering of pH.

In particular, the microbiologically impaired machining fluid must be replaced and disposed of after a short period of use, resulting in large economic losses.

In connection with the technical development of engineering production, a number of requirements have emerged in recent years for the production of suitable stabilized machining fluids against microbiological attack. A number of additives with antimlcrobial properties are currently used to prevent microbial decomposition of machining fluids. For example, sodium chromate, which is a skin allergen, has been applied and is therefore of limited use for hygiene reasons. Furthermore, a mixture of phenylmercuric chloride with tricresol, which has not been proven in operation, has created problems with the mercury-containing waste. Subsequently, diphenyloxalate, which decomposes readily in the alkaline environment of the machining liquids to form a toxic and irritating phenol. Again, antibiotics are effective for a short time and require daily intervention in the machining fluids and are also technically and economically demanding. The ethoxylated parachlorophenol in turn proved to be ineffective for the microbiological strains of interest found in the machining fluids. However, in other conditions, the active quaternary ammonium compounds are stable in the alkaline environment of the machining fluids, they decompose, smell and manifest themselves as skin allergens. Finally, the known alkylcinoxides cause skin irritation and inflammation and do not have a broad spectrum of antimicrobial activity.

It is clear from the above that the machining fluids used hitherto do not have sufficient antimicrobial properties to prevent the growth and multiplication of the most commonly occurring microbiological strains, so that the hygienic and technological properties of the machining fluids and other emulsions and possibly also of oil solutions are insufficient. However, this problem is solved by our invention in the form of a stabilized emulsion or oil solution for application to metallic materials, consisting of an aqueous emulsion or aqueous oil solution and 0.01 to 1% by weight. % of a stabilizer mixture consisting of 10 to 25 wt. % formaldehyde, 30-75 wt. alkanolamine C ₂ to C ₈ preferably monoethane. % of nolamine, 0.1 to 5 wt. % sodium or potassium nitrite, or 1,3-propanediol containing at least one of Br, J, NO, NO ₂ , 1 to 5 wt. di- or triethanolamine and the remainder up to 100 pens. wt. water.

The advantage of the solution according to the invention is to achieve a high antimicrobial effect at the same time while observing the parameters on the anticorrosive properties of machining fluids and easy application of the synergistic mixture into these fluids. The individual components are relatively readily available. Their action significantly increases the applicability of machining fluids and other emulsions and oil solutions.

The practical application of the invention can be illustrated by the following examples, which are shown in the tables, but which do not limit the scope of the invention.

According to the present invention, both laboratory and operational tests are performed to monitor the antimlrobial effects of the machining fluid.

Examples:

Laboratory tests for the determination of antimicrobial effects are carried out in such a way that the machining liquid consists of an aqueous emulsion of 5% emulsifying oil Emulsin II with additions of individual additives in the range of 0.0 to 0.1% by weight. is artificially infected with selected microbiological strains of Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Candida albicans and microbiological examination to determine the time for which the stabilized cutting fluid remains sterile.

The composition of the tested mixtures is as follows:

Mixture no. 1

21.3% wt. formaldehyde

42.6 wt. monoethanolamine,

0.2 wt. 2-bromo-2-nitro-l, 3-propanediol,

2.0 wt. % triethanolamine, and the remainder to 100 wt. water.

Mixture no. 2

13.3% wt. formaldehyde

64.0 wt. oktylamínaalkoholu.

0.1 wt. sodium nitrite,

3.0 wt. % diethanolamine and the remainder to 100 wt. water.

Mixture no. 3

18.2 wt. formaldehyde

36.8 wt. monoethanolamine,

4.0 wt. 2-iodo-2-nitro-l, 3-propanediol,

5.0 wt. triethanolamine and the remainder to 100% is water.

Mixture no. 4

21.3 wt. formaldehyde

42.6 wt. monoethanolamine,

0.3 wt. 2-bromo-2-nitro-l, 3-propanediol,

0.2 wt. sodium nitrite,

2.0 wt. triethanolamine,

5.0 wt. the polyetoxamer (10) of paranonylphenol and the remainder to 100% by weight is water.

Mixture no. 5

18.2 wt. formaldehyde

37.0 wt. monoethanolamine,

4.5 wt. 2-bromo-2-nitro-l, 3-propanediol,

5.0 wt. triethanolamine,

2.5 wt. the polyetoxamer (15) of lauryl alcohol and the remainder up to 100% by weight is water.

The results of the microbiological examination of the machining fluid are shown in Table 1.

Table 1

additive

Antimicrob. efficiency - sterility in days concentration in% wt.

0.03 0.05 0.10 Mixture no. 1 80 95 118 Mixture no. 2 58 70 91 Mixture no. 3 65 78 102 Mixture no. 4 83 100 120 Mixture no. 5 72 86 105 2-Bromo-2-nitro-l, 3-propanediol 14 18 22 formaldehyde 6 7 8 monoethanolamine 9 15 19 triethanolamine 6 6 7 Operational tests for monitoring anti- the grinding machine microbial effects are done by that sludge and other organic and inorganic swelling liquid consisting of water me impurities. During foundation fresh emulsion of 2 wt. emulsifying oil machining fluid with take samples, and Emulsin II, an alkalizing agent and anti- which are microbiologically examined for

Corrosive additives are stabilized by the addition of synergistic mixture no. 1 in an amount of 0.1 wt. and operates in a central distribution system of approximately 40 m ³ , the number of surviving microorganisms and the results given in Table 2.

Table 2 Time from foundation Without addition of fresh quartz synergistic] on days of mixture

Total number of microorganisms in 1 cm ³ .

2 3 4

1 more than 10 ⁵ WITH WITH WITH WITH WITH 2 3 more than 10 ⁵ WITH WITH WITH WITH WITH WITH WITH 5 more than 10 ⁶ WITH WITH WITH WITH WITH 10 (color and odor change) mixture change) WITH WITH WITH WITH WITH 15 WITH WITH WITH WITH WITH 20 WITH WITH WITH WITH WITH 25 WITH WITH WITH WITH WITH 30 WITH WITH WITH WITH WITH 35 WITH WITH WITH WITH WITH 40 WITH WITH WITH WITH WITH 45 WITH WITH WITH with WITH 50 with WITH WITH , with WITH 55 with more than 10 ⁵ WITH with WITH 60 with more than 10 ⁵ with with WITH 65 with more than 10 ⁵ with with WITH 70 with more than 10 ^β more than 10 ⁵ with WITH 75 with more than 10 ^e more than 10 ³ with more than 10 ³ 80 with change color more than 10 ³ with more than 10 ⁵ 85 with and odor - mixture change 10 ⁶ with more than 10 ⁵ 90 95 More than 10 ^δ More than 10 ⁵ change color more than 10 ^β with more than 10 ⁵ more than 10 ⁶ color change 100 105 more than 10 ⁵ more than 10 ⁶ color and odor change - mixture change and odor - mixture change change color and odor - change the mixture more than 10 ⁶ more than 10 ⁶ color and odor change - mix change and odor - mixture change

Where S stands for sterile environment.

The results in Table 2 show that the stabilized machining fluid has very good antimicrobial effects since already in the freshly prepared [unstabilized machining] fluid at the beginning, the total number of surviving microorganisms is on the order of more than 10 ⁵ in 1 cm ³ . In addition, according to the results of the chemical analyzes, the stabilized machining fluid is more stable, has very good anticorrosive properties and the odor is not seen until 75 days after the addition of the synergistic mixture no. 2, on the 90th day after the addition of mixture no. 3 and 5 and at 105 days after the addition of synergistic mixture no. 1 and 4, while in unstabilized [machining] liquids it smells even after 5 days.

Claims (2)

An antimicrobially stabilized machining liquid for application to metallic materials based on an aqueous emulsion or oil solution, characterized in that it contains from 0.01 to 1% by weight, calculated on the total weight of the stabilized mixture, of a synergistic stabilizing additive 10 to 25 wt. formaldehyde 30 to 75 wt. alkanolamine C ₂ to C _8, preferably monoethanolamine. 0.1 to 5 wt. sodium nitrite or 1,3-propanediol ynAlez containing at least one of Br, J, NO, NO ₂ , 1 to 5 wt. % di- or triethanolamine and the remainder to 100 wt. water. 2. The antimicrobially stabilized machining liquid according to claim 1, further comprising a surfactant of the polyetoxamers type of oxygen compounds with active hydrogen such as lauryl alcohol, p-nonylphenol in a concentration of 0.1 to 8% by weight, calculated on the total weight of the stabilized liquid.