DK152356B - FOR DEATHING OF METAL AND OTHER ITEMS SUITABLE WITH AN EPOXYESTER STABILIZED 1,1,1-TRICHLORETHAN PRODUCT AND METHOD OF DEATHING OF METAL AND OTHER ARTICLES USING THE PRODUCT - Google Patents

Description

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The present invention relates to a metal and other article suitable for degreasing, with an epoxy ester stabilized 1.1.1 trichloroethane product, and a method for degreasing metal and other articles using the product.

5 In recent years, there has been a growing use of 1,1,1-tri-chloroethane in industrial purification processes especially for degreasing metals. However, large-scale use of 1,1,1-trichloroethane, especially for steam degreasing, presents difficulties because in contact with reactive metals such as iron, zinc, copper and aluminum, the solvent is attacked. This leads to tar formation and the development of large quantities of acids.

Oet is known from Chemical Abstracts Vol. 81 (1974), Abstract No. 3332 t, to stabilize 1,1,1-trichloroethane down an 'epoxy cycloalkyl ester derived from an acid containing 7 carbon atoms and an alcohol containing 7 carbon atoms. However, these stabilizers are so low molecular weight that they are lost from the liquid solvent when boiled.

It has now been found that certain other epoxy esters or stabilizers containing these epoxy esters are very effective in reducing metal induced decomposition of 1.1.1 trichloroethane.

The product of the present invention is therefore advantageous in that it contains as a stabilizer at least one epoxy alkyl ester derived from a carboxylic acid containing 12-20 carbon atoms and an alcohol containing 3-12 carbon atoms in an amount of 0 , 05-5% by weight.

The carboxylic acid from which the ester is derived may contain, for example, 18 carbon atoms.

The preferred alcohols from which the esters are derived are those containing 3-8 carbon atoms.

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By the term "epoxy alkyl ester" is meant those compounds in which an epoxy group is introduced into the alkyl group in the alcohol and / or in the alkyl group in the carboxylic acid from which the ester is derived.

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The alkyl ester itself (into which the epoxy group is introduced) is derived from a carboxylic acid containing an n-alkyl, isoalkyl, alkenyl or cycloalkyl group and from an alcohol containing an n-alkyl, isoalkyl, alkenyl or cycloalkyl group. 5 group, or which is a polyol.

Examples of epoxy alkyl esters include e.g. octylepo = xystearate and butylepoxystearate. An example of an epoxy isoalkyl ester is epoxy-2-ethylhexyl stearate. An example of an epoxycycloalkyl ester is epoxycyclohexyl stearate. Mixtures of epoxy alkyl esters can be used.

A mixture of epoxy alkyl esters derived from long chain fat = 15 acids and glycerine is very useful as a stabilizing agent for the Γ, Ι, Ι-trichloroethane product of the invention. Particularly useful stabilizers are epoxidized vegetable oils, e.g. epoxidized soybean oil and epoxidized flaxseed oil ... containing such epoxy alkyl esters.

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The epoxy alkyl esters can be prepared in known manner, e.g. by epoxidizing the corresponding esters containing ethylenic unsaturation in the acid component and / or the alcohol component.

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The weight amounts of epoxy alkyl ester used are greater than 0.05% but not greater than 5% relative to the solvent. Eg. very good results can be obtained when the weight amount of the epoxy cooler ester is in the range of 0.1% to 2% by weight relative to the solvent.

One or more usual stabilizers for 1,1,1-trichloroethane may also be used in combination with the present novel stabilizers. Eg. useful results can be obtained when also incorporating the il, 1,1-trichloro-ethane product into a stabilizing amount of one or more of the following usual stabilizing compounds: organic nitrates, nitriles, nitroalkanes, cyclic ethers of 3-6 membered rings, amines , alcohols, alkyl esters

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3 and ketones. As a rule, any of these known stabilizers are present in an amount not greater than 4% by weight relative to the solvent. In fact, significantly lower amounts of the usual stabilizers can be used if desired.

The invention also relates to a method for degreasing metal and other articles which is characterized in that the articles are brought into contact with the above-mentioned stabilized 1,1,1-trichloroethane product in liquid or vapor state. In such a process, the 1,1,1-trichloroethane product may, if desired, also contain usual stabilizers.

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The following example illustrates the invention. The percentages mentioned are weight percentages.

Example 20

The apparatus included a bulb-shaped glass flask (capacity 3 100 cm) on which was mounted a vertical glass tube, which led to a water-cooled ± backbreaker. The tube was also provided with a horizontal glass side tube adjacent to another 25 horizontal glass tube. The ends of both the horizontal tubes were deformed so that by using a spring clip, as shown below, a desired amount of solvent could be withdrawn at the end of the second glass tube. The latter abutted a third glass tube which was bent at a right angle to connect it to a soft steel tube (length 15 cm, diameter 0.64 cm). Heat from a Meker burner was supplied through a center pipe (length 3 cm) of the soft steel vertical pipe. A glass tube connected = the soft steel tube through 2 right-angled bends 35 to the glass flask.

3 50 cm of 1,1,1-trichloroethane was placed in the glass flask. By heating the soft steel tube passed 1, l, l-trichloro =

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thus acted as thermosyphon. Thus, the circulating 1,1,1-trichloroethane was subjected to an accelerated stability test in the presence of soft steel.

Various amounts of epoxy alkyl esters with and without usual stabilizers were incorporated into the l, l, l-tri = 5 chloroethane and the mixture was subjected to an accelerating stability test for 120 minutes. Any initial acidity measured to pH 4 in the vapor (in the capacitor) and in the stabilized solvent was indicated by universal indicator paper.

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The results are shown in Table I.

TABLE I 15

Stabilizer Time for steam Time for liquid to become acidic 20 0.2% epoxidized no evidence of no evidence of soybean oil (I) acidity after acidity after known during the 120 minutes 120 minutes registered va = __ mark "Paraplex" 40 G62 and available from Rohm and Haas 0.5% epoxidized 30 soybean oil (I) plus 2% isopropyl = nitrate ditto ditto 0.5% nitromethane 0.5% epoxidized 35 soybean oil (I) plus ditto ditto 2% t-butanol 0.5% nitromethane 5

Stabilizer Time to steam Time for liquid to become acidic becomes acidic

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0.5% epoxidized no evidence of no evidence of soybean oil (I) acidity after acidity after plus 120 minutes 120 minutes 2% t-amyl alcohol 0.5% nitromethane 0.5% epoxidized soybean oil (I) plus ditto ditto 2% methyl ethyl ketone 0 , 5% nitromethane 0.5% epoxidized soybean oil (I) plus ditto ditto 3 ^ 5% 1,4-dioxane 0.5% nitromethane 0.5% epoxidized soybean oil (I) plus ditto ditto 2% isobutyl acetate 0.5% nitromethane 0.5% epoxidized soybean oil (I) plus ditto ditto 2% methyl 3-butyn-2-ol 0.5% nitromethane 0.5% epoxidized soybean oil (I) plus 2% 1,3-dioxolane ditto ditto 0.5 % nitromethane 0.05% acetaldehyde

Stabilizer Time to steam Time to cool. . gets angry ...... gets angry 6

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0.2% epoxidized in no evidence of no evidence of flaxseed oil (II) acidity after acidity after known under item = 120 minutes 120 minutes labeled "Edeno1" B316 and available from Henkel and Co.

0.5% epoxidized flaxseed oil (II) plus ditto ditto 2% isopropyl nitrate 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) plus ditto ditto 3.5% t-butanol 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) plus ditto ditto 2% t-amyl alcohol 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) plus ditto ditto 2% methyl ethyl = ketone 0.5% nitromethane 0.5% epoxidized flaxseed oil '(II) plus ditto ditto 3.5% 1,4-dioxane 0.5% nitromethane

Stabilizer Time to steam Time for liquid to turn sour 7

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0.5% epoxidized no evidence of no evidence of flaxseed oil (II) acidity after acidity after plus 120 minutes 120 minutes 2% isobutyl acetate 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) plus I ditto ditto 2% 2-methyl -3-j butyn-2-ol 0.5% nitromethane 0.5% epoxidized flaxseed oil (II) plus ditto ditto 2% 1,3-dioxolane 0.5% nitromethane 0.05% acetaldehyde dimethylhydrazone 0.25% epoxidized flaxseed oil (II) plus ditto ditto 3.5% 1,4-dioxane 0.5% nitromethane 0.25% 1,2-butene oxide 0.25% epoxidized flaxseed oil (II) plus ditto ditto 2.0% methyl ethyl = ketone 2, 0% nitromethane 0.25% 1,2-butene oxide ______1___ 0.2% epoxyethyl = ..... stearate. . ... ditto. . . ditto

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Stabilizer Time to steam Time for liquid to become acidic 0.2% epoxyoctyl = no sign of no sign of stearate acidity after acidity after plus 120 minutes 120 minutes 3.5% 1,4-dioxane 0.5% nitromethane 0 , 5% epoxy-2-ethyl hexyl stearate (III) known under product = labeled "Edenol" ditto ditto B74 and available from Henkel and Co 0.5% (III) plus ditto ditto 2% isopropyl nitrate 0.5% nitromethane 0.5% (III) plus ditto ditto 2% t-butanol 0.5% nitromethane 0.5% (III) plus 2% t-amyl alcohol ditto ditto 0.5% nitromethane 0.5% (III) plus 2% methyl ethyl = ditto ditto ketone 0.5% nitromethane

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Stabilizer Time for steam Time for liquid to become acidic, to become acidic 0/5% (III) no evidence of no sign of plus acidity after acidity after 3.5% 1,4-dioxane 120 minutes 120 minutes 0.5% nitromethane 0.5% (III) plus 2% isobutyl acetate ditto ditto 0.5% nitromethane 0.5% (III) plus 2% 2-methyl-3-bu = tyn-2-ol ditto ditto 0.5% nitromethane 0, 5% (III) plus 2% 1,3-dioxolane 0.5% nitromethane ditto ditto 0.5% acetaldehyde dimethylhydrazone 0.5% epoxycyclo = hexyl stearate (IV) known under the trade mark = ditto ditto ditto "Edenol" HS235 and as available from Henkel and Co.

0.5% (IV) plus ditto ditto 2% isopropyl nitrate 0.5% nitromethane

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Stabilizer Time to steam Time for liquid to become acidic. becomes acidic 0.5% (IV).

no signs of no signs of US acidity after acidity after 2% t-butanol, 120 minutes 120 minutes 0.5% nitromethane 0.5% (IV) plus 2% t-amyl alcohol ditto ditto 0.5% nitromethane 0, 5% (IV) plus 2% methyl ethyl = ketone ditto ditto 0.5% nitromethane 0.5% (IV) plus 3.5% 1,4-dioxane ditto ditto 0.5% nitromethane 0.5% (IV) plus 2% isobutyl acetate ditto ditto 0.5% nitromethane 0.5% (IV) plus 2% 2-methyl-3-bu = tyn-2-ol ditto ditto 0.5% nitromethane 0.5% (IV) plus 2% 1,3-dioxolane 0.5% nitromethane ditto ditto 0.05% acetaldehyde dimethylhydrazone

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In these experiments, all possible signs of starting acidity did not appear in the vapor or liquid long after the 120-minute period, even up to several hours. With a stabilizing mixture consisting of 0.5% "Edenol" B316 + 5 2% isopropyl nitrate and 0.5% nitromethane, for example. in = beginning acidity in the steam or in the liquid after 14 hours.

Comparison.

In comparison, said accelerated heat stability = 10 liters test was performed to determine the time to develop acidic conditions shown with universal indicator paper to pH4 with 1,1,1-trichloroethane stabilized with non-inventive stabilizing materials. The results are shown in Table II.

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TABLE II

Stabilizer Time for steam Time for liquid to become acidic becomes 0.2% 1,2-butene = oxide 5 min. 25 min.

2% isopropyl = nitrate 0.5% nitromethane 4 min. 4 min.

2% t-amyl alcohol 0.5% nitromethane 15 min. 19 min.

2% methyl ethyl = ketone 5% nitromethane 20 min. 20 min.

3.5% 1,4-dioxane 0.5% nitromethane 15 min. 6 min.

2% isobutyl acetate 0.5% nitromethane 2 min. 3 min.

2% 2-methyl-3-bu = tyn-2-ol 0.5% nitromethane 3 min. 20 min.

2% 1,3-dioxolane 0.5% nitromethane 0.05% acetaldehyde dimethylhydrazone 5 min. 40 min.

2% isopropyl nitrate 0.5% 1,2-butene oxide 0.5% nitromethane 5 min. 5 min.

2% 1,3-dioxolane 0.5% 1,2-butene oxide 0.5% nitromethane 5 min. 10 min.

Claims (2)

1. For degreasing metal and other articles suitable with an epoxy ester stabilized 1,1,1-trichloroethane product, characterized in that it contains as a stabilizer at least one epoxy alkyl ester derived from a carboxylic acid containing 12-20 carbon atoms and of an alcohol containing 3-12 carbon atoms, in an amount of 0.05-5% by weight. A 1,1,1-trichloroethane product according to claim 1, characterized in that the alcohol component from which the ester is derived contains from 3 to 8 carbon atoms. A 1,1,1-trichloroethane product according to any one of the preceding claims, characterized in that the epoxy ester is derived from a carboxylic acid containing an n-alkyl, isoalkyl, alkenyl or cycloalkyl group and an alcohol containing an n-alkyl -, isoalkyl, alkenyl or cycloalkyl group or one polyol. A 1,1,1-trichloroethane product according to claim 3, characterized in that the epoxy alkyl ester is octyl epoxy stearate. A 1,1,1-trichloroethane product according to claim 3, characterized in that the epoxy alkyl ester is butyl epoxy stearate. A 1,1,1-trichloroethane product according to claim 3, characterized in that the epoxyisoalkyl ester is epoxy-2-ethylhexyl stearate. A 1,1,1-trichloroethane product according to claim 3, characterized in that the epoxycycloalkyl ester is epoxycyclohexyl stearate. A 1,1,1-trichloroethane product according to claim 3, characterized in that the stabilizing agent for 1,1,1-trichloroethane is a mixture of epoxy alkyl esters derived from long chain 35 fatty acids with a maximum of 20 carbon atoms and glycerine. A 1,1,1-trichloroethane product according to claim 8, characterized in that the stabilizer for 1,1,1-trichloroethane is an epoxidized vegetable oil. A 1,1,1-trichloroethane product according to claim 8, characterized in that the stabilizing agent for 1,1,1-trichloroethane is an epoxidized soybean oil. 11. A 1,1,1-trichloroethane product according to claim 8, characterized in that the stabilizer for 1,1,1-trichloroethane is an epoxidized flaxseed oil. 12. A 1,1,1-trichloroethane product according to any one of the preceding claims, characterized in that a further stabilizing amount of one or more of the following usual stabilizing agents is incorporated: organic nitrates, nitriles , nitroalkanes, cyclic ethers of 3-6-membered rings, amines, alcohols, alkyl esters and ketones. Method of degreasing metal and other articles, characterized in that the articles are brought into contact with a stabilized 1,1,1-trichloroethane product according to any one of claims 1-12 in liquid or vapor state. 20 25 30 35