FI65985C - FOER AVLAEGSNING AV FETT FRAON METAL- OCH ANDRA YTOR LAEMPLIG1,1,1-TRICHLORETAN-PRODUKT - Google Patents

Description

. ".-- I r> 1 ADVERTISEMENT

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England-England (GB) 6595/78 (71) Imperial Chemical Industries Limited, Imperial Chemical House,

Millbank, London SW1P 3JF, England-England (GB) (72) Christopher Storm Allen, Runcorn, Cheshire, England-England (GB) (74) Oy Kolster Ab (54) Suitable for degreasing metal and other surfaces 1,1, The present invention relates to a 1,1,1-trichloroethane product suitable for degreasing metal and other surfaces.

In recent years, there has been an increasing use of 1,1,1-trichloroethane in industrial cleaning processes, particularly in metal degreasing. However, the large-scale use of 1,1,1-trichloroethane, especially in steam degreasing, presents difficulties because reactive metals such as iron, zinc, copper and aluminum have a degrading effect on this solvent. This results in the formation of a tarry substance and the release of large amounts of acid.

It has now been found that certain epoxy esters are very effective in reducing metal-induced degradation of 1,1,1-trichloroethane.

2 65985

The 1,1,1-trichloroethane product according to the invention is characterized in that it contains, as a stabilizing agent, 0.05 to 5% by weight of epoxyalkyl ester, based on 1,1,1-trichloroethane, which ester is derived from a carboxylic acid having 12 to 22 carbon atoms. and an alcohol having 3 to 8 carbon atoms.

By the term "epoxyalkyl ester" is meant a compound in which the epoxy group is attached to the alkyl group of the alcohol and / or the alkyl group of the carboxylic acid from which the ester is derived.

The alkyl ester itself (to which the epoxy group is attached) may be derived from a carboxylic acid containing an n-alkyl, isoalkyl or cycloalkyl group and an alcohol containing an n-alkyl, isoalkyl, alkenyl or cycloalkyl group or which is a polyol.

Examples of epoxyalkyl esters are octyl epoxystearate and butyl epoxystearate. An example of an epoxy isoalkyl ester is epoxy-2-ethylhexyl stearate. An example of an epoxycycloalkyl ester is epoxycyclohexyl stearate.

Mixtures of epoxyalkyl esters can also be used.

A mixture of epoxyalkyl esters derived from long chain fatty acids and glycerol is highly preferred as a stabilizer for the 1,1,1-trichloroethane product of the invention. Particularly good stabilizers are also epoxidized vegetable oils, for example epoxidized soybean oil and epoxidized flaxseed oil, which contain such epoxyalkyl esters.

Epoxyalkyl esters can be prepared in a known manner, for example by epoxidizing the corresponding esters containing ethylenic unsaturation in acid and / or alcohol components.

Fairly small amounts by weight of epoxyalkyl esters, for example epoxidized vegetable oil, are sufficient. Usually the amount of epoxyalkyl ester is greater than 0.05% by weight based on 1,1,1-trichloroethane. For example, very good results can be obtained when the weight of the epoxyalkyl ester is between 0.1 and 2% by weight, based on 1,1,1-trichloroethane.

One or more conventional 1,1,1-trichloroethane stabilizers may also be added in accordance with the invention. For example, good results can be obtained when a stabilizing amount of one or more conventional stabilizing compounds, such as organic nitrates, nitriles, nitroalkanes, cyclic ethers with 3-6-membered rings, is also added to 1,1,1-trichloroethane. , amines, alcohols, alkyl esters and ketones. Any of these known stabilizers are usually present in an amount of up to 4% by weight, based on the solvent. In fact, considerably smaller amounts of said conventional stabilizers can be used if desired.

The product of this invention can also be prepared by diluting concentrated solutions of epoxyalkyl ester in which the weight amounts of epoxyalkyl ester are much higher than the above-mentioned 5% by weight. These solutions may contain from 20 to 70% by weight of epoxyalkyl esters, for example epoxybutyl stearate, and epoxidized vegetable oil based on 1,1,1-trichloroethane. Addition of such a concentrate to pure 1,1,1-trichloroethane or to a product from which the concentration of said epoxyalkyl ester has been consumed can give 1,1,1-trichloroethane containing small amounts of epoxyalkyl ester, which can thus be used for the purification or for other purposes. Concentrates which contain not only a large amount of epoxyalkyl ester by weight but also a large amount of a conventional stabilizer or stabilizers can also be used.

The present invention also relates to a process for preventing the decomposition of 1,1,1-trichloroethane due to the presence of metals, which process is characterized in that the epoxyalkyl ester described above is added to the 1,1,1-trichloroethane product, and optionally other conventional stabilizers.

The invention also relates to a method for degreasing, in particular to degreasing metal and other surfaces, which method is characterized by contacting the surface to be treated with a 1,1,1-trichloroethane product in a liquid or vapor space stabilized with an epoxyalkyl ester, and which product may also contain other conventional stabilizers.

The following example illustrates the invention. When percentages are mentioned, they are percentages by weight.

4

Example 65985

The apparatus consisted of a pear-shaped glass flask (capacity 100 cm) above which was a vertical glass tube leading to a water-cooled reflux condenser. The tubes were also equipped with a horizontal glass side tube bounded by another horizontal glass tube. The ends of both horizontal tubes were thus bent so that by using a spring clip, as desired below, the desired amount of solvent could be removed from the end of the second glass tube. The latter was limited to a third glass tube bent at right angles to connect it to a carbon steel tube (length 15 cm, diameter 0.64 cm). The heat from the Meker burner was applied through a cover tube to the center of a vertical carbon steel tube (length 3 cm). The glass tube connected the steel tube through two rectangular bends to the glass flask.

3 50 cm of 1,1,1-trichloroethane were placed in a glass flask. When the carbon steel tube was heated, 1,1,1-trichloroethane passed through the glass side branches and the carbon steel tube, thus acting as a heat sink. The circulating 1,1,1-trichloroethane was thus subjected to an accelerated stability test in the presence of carbon steel.

Various amounts of epoxyalkyl esters and conventional stabilizers were added to 1,1,1-trichloroethane and the mixture was subjected to an accelerated stability test for 120 minutes. The possible appearance of acidity was detected in steam (condenser) and stabilized solvent by means of a general indicator paper.

The results are shown in the following table.

Table I

Stabilizer Vapor Liquid Acidity Acidity 0.2 Epoxidized Soybean- Not Detected No oil (I), known as acid-formic acid-registered commercial dipping waxy "Paraplex G62" and commercially available from Rohm & Haas (cont. ) 5 65985 (Table I cont.)

Stabilizer Vapor Liquid acidity 0.5% epoxidized soybean- Not observed No oil (I) and 2% isopropylic acid formate nitrate and dark matter 0.5% nitromethane 0.5% epoxidized soybean oil (I) ) and 2% t-butanol and 0,5% nitromethane "" 0,5% epoxidised soybean oil (I) and 2% t-amyl alcohol and 0,5% nitromethane 0,5% epoxidized soybean oil (I) ) and 2% methyl ethyl ketone and 0,5% nitromethane "" 0,5% epoxidised soybean oil (I) and 35% 1,4-dioxane and 0,5% nitromethane 0,5% epoxidised soybean oil (I) ) and 2% isobutyl acetate and "0,5% nitromethane 0,5% epoxidised soybean oil (I) and 2-methyl-3-butyn-2-ol and 0,5% nitromethane" "0,5% epoxidized soybean oil (I) and 2% 1,3-dioxolane, 0,5% nitromethane and 0,05% acetaldehyde dimethylhydrazone "" 0,2% epoxidised linseed oil (II) known under the trade name "Edenol" B316 and commercially available the

Henkel & Co. from "" (cont'd) 6 65985 (Table I cont.)

Stabilizer Vapor Liquid acidity 0.5% epoxidized flaxseed Not observed Seed oil (II) and acid form acid not detected 2% isopropyl nitrate and dark matter 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) and 35 % t-butanol and 0,5% nitromethane "" 0,5% epoxidised linseed oil (II) and 2% t-amyl alcohol and 0,5% nitromethane 0,5% epoxidised linseed oil (II) and 2 % methyl ethyl ketone and 0,5% nitromethane "" 0,5% epoxidised linseed oil (II) and 3,5% 1,4-dioxane and 0,5% nitromethane 0,5% epoxidised linseed oil (II) and 2 % isobutyl acetate and 0,5% nitromethane "" 0,5% epoxidised linseed oil (II) and 2% 2-methyl-3-butyn-2-ol and 0,5% nitromethane 0,5% epoxidised linseed oil seed oil (II) and 2% 1,3-dioxolane, 0,5% nitromethane and 0,05 acetaldehyde dimethylhydrazone "" 0,25% epoxidised linseed oil (II) and 3,5% 1,4 -dioxane, 0.5% nitromethane and 0.25% 1,2-butene oxide (cont'd) (Table I, cont'd) 65985

Stabilizer Vapor Liquid acidity 0.25% epoxidized flax- Not observed No seed oil (II) and acid-formed acid was detected 2.0% methyl ethyl ketone, darkened 2.0% nitromethane and 0.25% 1,2-butene oxide 0.2% epoxyoctyl stearate 0.2% epoxyoctyl stearate and 3.5% 1,4-dioxane and 0.5% nitromethane 0.5% epoxy-2-ethylhexyl stearate (III) known under the trademark "Edenol" B 74 and commercially available

Henkel & Co. "0.5 (III) plus 2% isopropyl nitrate and 0.5% nitromethane" "0.5% (III) and 2% t-butanol and 0.5% nitromethane" "0.5 % (III) and 2% t-amyl alcohol and 0,5% nitromethane 0,5% (III) and 2% methyl ethyl ketone and 0,5% nitromethane 0,5% (III) and 3,5% 1,4 -dioxane and 0,5% nitromethane "" 0,5% (III) and 2% isobutyl acetate and "" 0,5% nitromethane 0,5% (III) and 2% 2-methyl-3-butyn-2-ol and 0.5% nitromethane "" (cont.) (Table I, cont.) 8 65985

Stabilizer Vapor Liquid acidity 0.5% (III) and Not observed Not detected 2% 1,3-dioxolane »acid form acid form 0.5% nitromethane / dark 0.5% acetaldehyde and 35% dimethylhydrazone

0.5% epoxycyclohexyl stearate (IV), known under the trademark "Edenol" HS

235 and commercially available from Henkel & Co. 0.5% (IV) plus 2% isopropyl nitrate and 0.5% nitromethane 0.5% (IV) and 2% t-butanol and 0.5% % nitromethane "" 0,5% (IV) and 2% t-amyl alcohol and "0,5% nitromethane 0,5% (IV) and 2% methyl ethyl ketone and 0,5% nitromethane" "0,5% (IV) and 3.5% 1,4-dioxane and 0.5% nitromethane "" 0.5% (IV) and 2% isobutyl acetate and 0.5% nitromethane "" 0.5 (IV) and 2% 2-methyl-3 -butyn-2-ol and 0.5% nitromethane "" 0.5% (IV) plus 2% 1,3-dioxolane, 0.5% nitromethane and 0.05% acetaldehyde methylhydrazone "" 9 65985

All results obtained from these times indicated that no decomposition occurred in steam or liquid during the 120 minute treatment.

With the stabilized mixture containing 0.5% "Edenol" B 316 and 2% isopropyl nitrate and 0.5% nitromethane, no decomposition could be observed in steam or liquid even after 14 hours of treatment.

Comparison

For comparison, said accelerated thermal stability test was performed to determine the time taken for the development of acidic conditions as indicated by general indicator paper (pH 4) using the known 1,1,1-trichloroethane product. The results are shown in Table II.

Table II

Stabilizer Time to vapor change Time to liquid acidification 0.2% 1,2-butene oxide 5 min 25 min 2% isopropyl nitrate and 4 min 4 min 0.5% nitromethane 2% t-amyl alcohol and 0.5% nitromethane 4 min 19 min 2% t-amyl alcohol and 0.5% nitromethane 15 min 19 min 2% methyl ethyl ketone and 5% nitromethane 20 min 20 min 3.5% 1,4-dioxane and 0.5% nitromethane 15 min 6 min 2% isobutyl acetate and 0.5% nitromethane 2 min 3 min 2% 2-methyl-3-butyn-2-ol and 0.5% nitromethane 3 min 20 min 2% 1,3-dioxolane, 0.5% nitromethane and 0, 05% acetaldehyde dimethyl hydrazone 5 min 40 min (cont.) (Table II, cont.) 10 65985

Stabilizer Time of vapor change- Time of acidification of liquid 2% isopropyl nitrate, 0,5% 1,2-butene oxide 3a 0,5% nitromethane 5 min 5 min 2% 1,3-dioxolane> 0,5% 1, 2-butene oxide and 0.5% nitromethane for 5 min 10 min

Claims (15)

1. Suitable 1,1,1-trichloroethane product suitable for removing fat from metal and other surfaces, characterized in that the solid stabilizing agent contains 0.05 to 5% by weight of epoxy cooling ester, calculated on 1.1 trichloroethane, which ester is derived from a carboxylic acid containing 12-22 carbon atoms and an alcohol containing 3-8 carbon atoms. A 1,1,1-trichloroethane product according to claim 1, characterized in that the epoxy ester is derived from a carboxylic acid containing an n-alkyl, iso-alkyl, alkenyl or cycloalkyl group, and an alcohol containing an n-alkyl -, iso-alkyl, alkenyl or cycloalkyl group, or a polyol. A 1,1,1-trichloroethane product according to claim 2, characterized in that the epoxy alkyl ester is octyl epoxy stearate. 4. A 1,1,1-trichloroethane product according to claim 2, characterized in that the epoxy alkyl ester is butyl epoxy stearate. A 1,1,1-trichloroethane product according to claim 2, characterized in that the epoxy-iso-alkyl ester is an epoxy-2-ethylhexyl stearate. A 1,1,1-trichloroethane product according to claim 2, characterized in that the epoxy cycloalkyl ester is an epoxy cyclohexyl stearate. A 1,1,1-trichloroethane product according to claim 2, characterized in that the stabilizer is a mixture of epoxyalkyl esters derived from long chain fatty acids and glycerol. 8. A 1,1,1-trichloroethane product according to claim 2, characterized in that the stabilizer is an epoxidized vegetable oil. 9. A 1,1,1-trichloroethane product according to claim 8, characterized in that the stabilizer is an epoxidized soybean oil. 10. A 1,1,1-trichloroethane product according to claim 8, characterized in that the stabilizer is an epoxidized linseed oil.