US3653983A

US3653983A - Compositions for displacing water adhering to metal surfaces and process

Info

Publication number: US3653983A
Application number: US876604A
Authority: US
Inventors: Georg Ziehr; Heinz-Dieter Heidenbluth
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1968-11-22
Filing date: 1969-11-13
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04
Also published as: BR6914387D0; ES373762A1; BE742039A; CH542291A; NL6916088A; DE1810245A1; GB1251909A; FR2023901A1; AT288109B; JPS5238989B1

Abstract

A composition for the displacing of an aqueous film or layer adhering to a metal surface consisting essentially of an organic water-immiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to 10 percent of an acid selected from the group consisting of monocarboxylic acid having from seven to 12 carbon atoms and mixtures of monocarboxylic acids having an average of from seven to 12 carbon atoms and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from six to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from 15 to 17; as well as the process of removing adhering liquid utilizing said composition.

Description

States t Ziehr et a1. 5] Apr. 4, 1972 s41 COMPOSITIONS FOR DISPLACING 3,397,150 8/1968 Burt et al. ..252/194 WATER ADHERING TO METAL 3,466,207 9/1969 Vincent et a1. ..l48/6.2 SURFACES AND PROCESS FOREIGN PATENTS OR APPLICATIONS 1721 Invent (1W8 Dusseldorf-flolthausen; 623,004 3/1963 Belgium 148/614 Heinz-Dieter I-Ieidenbluth, Dusseldorf, both of Germany Primary ExaminerRalph S. Kendall [73] Assignee: Henkel & Cie GmbH, Dusseldorf- Att0'"ey Hammnd Lute H 1th G o ausen ermany ABSTRACT 22 F1 d: N 13 1969 1 l C 0v A composition for the displacing of an aqueous film or layer [21] App]. No.: 876,604 adhering to a metal surface consisting essentially of an organic water-immiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less [30] Foreign Apphcauon Prlomy Data than 0.9 gm./ml. and a mixture of miscible organic water-im- Nov. 22, 1968 Germany ..P 18 10 245.9 miscible solvents, said mixture having a density of less than gm./m1., containing from 0.1 to 10 percent of an acid selected 52 us. c1. ..l48/6.14 R, 34 9, 252 194, from the group consisting of monocarboxylic acid having from 5 392 seven to 12 carbon atoms and mixtures of monocarboxylic [51] Int. Cl ..B01d 12/00 acids having an average of from seven to 12 carbon atoms and [58] Field of Search ..148/6.14, 615- 34/9- 252 194 from 8 Percent of alkylamine selwed the 2527392 group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from 56 R f d six to 10 carbon atoms, the average sum of the carbon atoms 1 e erences l e in said acid and said alkylamine being from 15 to 17; as well as UNITED STATES PATENTS the process of removing adhering liquid utilizing said composition. 2,250,508 7/1941 Thompson et al. ..148/6.14 3,003,247 10/1961 Sherliker ..34/9 8 Claims, N0 Drawings COMPOSITIONS FOR DISPLACING WATER ADHERING TO METAL SURFACES AND PROCESS THE PRIOR ART In the surface treatment of metal articles with aqueous solutions it is usually necessary to remove adhering aqueous liquid films or layers from the metal surfaces. After rinsing with water, the parts are generally dried with warm air. When the water is evaporated, small drops are formed which may lead to spots or stains. Frequency the last traces of liquid are only difficulty removed, even by use of compressed air, from blind holes and bore holes in the metal objects. Attempts have also been made to use absorbents for drying moist objects. This method is effective, but is time-consuming and generally unsuitable, for example, for the treatment of objects containing drill holes.

A special method is drying with use of organic solvents. In such case the water may be removed azeotropically by means of solvent vapors. In the immersion process, it is also known to displace the water by organic solvents when certain surfaceactive compounds such as, for example, quaternary ammonium compounds, fatty acid polyglycol esters or similar compounds are added to these solvents. However, it has been found in this known method the displaced water easily becomes emulsified and then residues remain on the surface.

OBJECTS OF THE INVENTION An object of the present invention is the development of a composition and a process for removing adhering aqueous films or layers from metal surfaces while avoiding the drawbacks of the prior art.

Another object of the invention is the obtaining of a composition for the displacing of an aqueous film or layer adhering to a metal surface consisting essentially of an organic waterimmiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to 10 percent of an acid selected from the group consisting of monocarboxylic acid having from seven to 12 carbon atoms and mixtures of monocarboxylic acids having an average of from seven to 12 carbon atoms and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from 6 to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from l to I7.

A yet further object of the invention is, in the process of removing an adhering aqueous film or layer from a metal surface by the steps of displacing said adhering aqueous film or layer on a metal surface with an organic solvent composition and removing said organic solvent from said metal surface the improvement which comprises utilizing, as said organic solvent composition, a composition for the displacing of an aqueous film or layer adhering to a metal surface consisting essentially of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to percent of an acid selected from the group consisting of monocarboxylic acid having from seven to 12 carbon atoms and mixtures of monocarboxylic acids having an average of from seven to 12 carbon atoms and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from six to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from 15 to 17.

These and other objects of the invention will become more apparent as the description thereof proceeds.

DESCRIPTION OF THE INVENTION In one aspect, therefore, the present invention provides a composition, for the removal of aqueous liquid films or layers from a metal surface comprising a water-immiscible organic solvent, or mixture of such solvents having a density or an average density of less than 0.9 gm./ml., containing from 0.1 to 10 percent by weight of a monocarboxylic acid or a mixture of monocarboxylic acids, having an average of from seven to 12 carbon atoms and 0.1 to 8 percent by weight of an alkylamine having six to 10 carbon atoms, or a mixture thereof having an average of from six to 10 carbons atoms, the sum of carbon atoms in the carboxylic acid and the alkylamine being 15 to 17.

In a further aspect, the present invention provides a process for the removal of an aqueous liquid film or layer adhering to a metal surface comprising treating said metal surface with a water-immiscible organic solvent or a mixture of such solvents having a density or an average density of less than 0.9 gm./ml., containing from 0.1 to 10 by weight of a monocarboxylic acid, or a monocarboxylic acid mixture having an average of from seven to 12 carbon atoms, and 0.1 to 8 percent of an alkylamine with six to 10 carbon atoms, or a mixture thereof having an average of from six to 10 carbon atoms, the sum of carbon atoms in the carboxylic acid and alkylamine being l5 to 17, in order to displace said aqueous liquid film or layer from the surface of said metal surface.

Hydrocarbon fractions with a density of less than 0.9 gm./ml. are generally suitable as the organic solvent mixtures immiscible with water. If desired, small amounts of chlorinated hydrocarbons may be added as long as they are water-immiscible and miscible with the hydrocarbon fractions and the average density of the mixture is less than 0.9 gm./ml.

It is generally advantageous to keep the density of the solvent as low as possible in order to bring about a rapid separation of the displaced water. Hydrocarbons with boiling ranges between and 250 C. or fractions from this boiling range are generally used. Apart from this, organic solvents of the said type possess a relatively low flammability and, after the metal articles are removed from the treatment bath, ensure a rapid evaporation of the solvent.

The carboxylic acids used may be straight or branched chains, natural or synthetic monocarboxylic acids or their mixtures, having an average of from seven to 12 carbon atoms in the molecule. For example, alkanoic acids having from seven to 12 carbon atoms, such as oenanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid or the branched acids corresponding to these carboxylic acids may be used. In addition to these aliphatic carboxylic acids, aromatic carbox ylic acids, such as phenylalkanoic acids and alkylphenylalkanoic acids having from seven to 12 carbon atoms, especially benzoic acids, may also be used. The carboxylic acid used can preferably be a readily accessible, commercial fatty acid mixture which contains a preponderance of caprylic, capric and lauric acids. Such mixtures are obtained, for example, as the first distillate during the working up of natural fats and usually consist of about 50 percent of caprylic acid, 40 percent of capric acid and 5 percent of lauric acid, as well as small amounts of lower carboxylic acids. This mixture of alkanoic acids from the first distillate has an average of nine carbon atoms.

Suitable alkylamines having six to 10 carbon atoms are preferably primary amines such as hexylamine, octylamine and decylamine, or mixtures thereof. The monocarboxylic acids or mixtures of monocarboxylic acids and the alkylamines or their mixtures are preferably used in approximatly equimolecular amounts. Small excesses of carboxylic acid or alkylamine, however, have no effect on the activity.

Compositions are preferably used which contain from 0.3 to 3 percent by weight each of carboxylic acid and alkylamine. Basically compositions with a content of carboxylic acid and alkylamine each of less than 0.3 percent can be also make, but their stability is too low for a technical product. With higher concentrations of carboxylic acid and aklylamine, alkylamine, a slight film remains on the metal surfaces which, however, exerts a positive influence on their storability.

It is essential that the total number of carbon atoms in the carboxylic acid and alkylamine should be to 17. In the case of mixtures the calculated average number of carbon atoms is decisive as the carbon number of the carboxylic acid and the alkylamine. If the carbon number is too small, multilayer liquid systems are formed on the introduction of water. The efficiency of the water displacement is too low. If, on the other hand, the total carbon atoms number is too high, emulsions are formed with the displaced water.

In order to remove the aqueous liquid layers, the wet metal surfaces are preferably introduced for a short time into a bath which contains the above-indicated components. In general, a treatment period of a few seconds is sufficient to free the metal surfaces from the adherent film of water. The displaced water is easily separated. No formation of emulsions occurs, so that the water can be easily removed. The metal parts are then taken out of the bath. After evaporating the solvent, hydrophobic surfaces from the residual acid and amine remain which give a temporary protection against corrosion. If it is desired to store the metal objects for a long period, a customary fat for protection against corrosion, such as for example wool fat or vaselines, can be incorporated in the compositions according to the invention.

The following specific embodiments are illustrative of the practice of the invention without being deemed limitative in any respect.

The percentage figures given in the following Examples are percentages by weight, unless the contrary is indicated.

EXAMPLE I la. Dirty metal articles, which were first treated with an alkaline cleaning solution and were then thoroughly rinsed with water, were immersed in the wet state in a bath of the follow' ing composition 1.2 percent of first distillate of a fatty acid mixture from the working up of natural fats (calculated carbon number 9) and 1.0 percent of octylamine, dissolved in a mixture of 93.8 percent of hydrocarbon fraction with a boiling range at 760 mm. Hg of 180 to 210 and 4.0 percent of perchlorethylene (Average sum of the carbon atoms in the acid and amine =17).

The water adhering to the surface was immediately displaced without the information of an emulsion or a multiphase in the bath. On taking the parts from the solvent the small amount of solvent evaporated, and dry hydrophobic metal surfaces were obtained.

Ib. For comparison, the metal objects were treated, with otherwise the same method, with a solution in the immersion process which contained 2 percent caprylic acid 1.5 percent hexylamine 96.5 percent of a hydrocarbon with a boiling range at 760 mm. Hg of 180 to 210C,

The total carbon number of the composition was therefore 14.

A displacement of water from metal surfaces indeed also occurred, but after incorporating a small amount of water, the composition separated into three layers.

Ic. In a further comparative experiment, the metal objects were finally immersed in a solution which contained:

2 percent lauric acid 1 percent hexylamine 97 percent of a hydrocarbon with a boiling range at 760 mm. Hg of 180 to 210 C. with otherwise the same method of operation. The total carbon number of the composition was therefore 18.

A displacement of the film of water likewise occurred, but the water removed formed an emulsion at the interface with the organic phase, particularly when movement of the bath occurred when the parts were put in and taken out.

EXAMPLE 2 Oiled metal sheets contaminated with a machine oil were treated with an acid cleaner and then rinsed with water. The sheets were then dipped in a bath of the following compositlons:

2.2 percent of a mixture of caprylic acid and lauric acid (proportion 2: 1)

1.5 percent hexylamine 96.3 percent of an aliphatic hydrocarbon mixture with a boiling range at 760 mm. Hg of 155 to 195. (Average sum of the carbon atoms in the acid and amine =15 1 3 After taking the sheets out of the bath and evaporating the solvent, clean dry surfaces were obtained.

EXAMPLE 3 Slightly soiled metal parts were treated with a neutral cleaner and then rinsed with water. The metal parts were then immersed in a bath of the following composition:

5.6 percent caprylic acid and 5.0 percent octylamine, dissolved in 89.4 percent of an aliphatic hydrocarbon mixture with a boiling range at 760 mm. Hg of 155 to 210 C.

After a few seconds the water adhering to the surface was displaced, and after the removal of the metal parts from the bath and evaporation of the solvent, a dry hydrophobic metal surface was obtained.

Practically the same results were obtained if, instead of the above-described bath, a bath of the following composition was used:

1.2 percent benzoic acid and 1.6 percent decylamine, dissolved in 92.2 percent of a hydrocarbon with a boiling range at 760 mm. Hgof lto 210C 5.0 percent perchlorethylene.

The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art may be utilized without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. A composition for the displacing of an aqueous film or layer adhering to a metal surface consisting essentially of an organic water-immiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to 10 percent of a monocarboxylic acid having an average of from seven to 12 carbon atoms selected from the group consisting of 1 alkanoic acids, 2) phenylalkanoic acids, 3) alkylphenylalkanoic acids 4) mixtures thereof and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from six to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from 15 to 17.

2. The composition of claim 1 wherein said acid and said alkylamine are present in substantially equimolecular amounts.

3. The composition of claim 1 wherein said acid is a technical fatty acid mixture consisting preponderantly of caprylic, capric and lauric acids.

4. The composition of claim 1 wherein said acid is benzoic acid.

5. The composition of claim 1 wherein said organic waterimmiscible solvent is predominately a hydrocarbon fraction.

6. The composition of claim 5 wherein said hydrocarbon fraction has a boiling point range within the range to 250 C.

7. The composition of claim 5 having a further content of a chlorinated hydrocarbon.

8. In the process of removing an adhering aqueous film or layer from a metal surface by the steps of displacing said adhering aqueous film or layer on a metal surface with an organic solvent composition and removing said organic solvent from said metal surface, the improvement which comprises utilizing as said organic solvent composition, a composition consisting essentially of an organic water-immiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to 10 percent of a monocarboxylic acid having an average of from seven to 12 carbon atoms selected from the group consisting of l) alkanoic acids, 2) phenylalkanoic acids, 3) alkylphenylalkanoic acids and 4) mixtures thereof and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from six to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from 15 to l7.

nun-m

Claims

2. The composition of claim 1 wherein said acid and said alkylamine are present in substantially equimolecular amounts.
3. The composition of claim 1 wherein said acid is a technical fatty acid mixture consisting preponderantly of caprylic, capric and lauric acids.
4. The composition of claim 1 wherein said acid is benzoic acid.
5. The composition of claim 1 wherein said organic water-immiscible solvent is predominately a hydrocarbon fraction.
6. The composition of claim 5 wherein said hydrocarbon fraction has a boiling point range within the range 150* to 250* C.
7. The composition of claim 5 having a further content of a chlorinated hydrocarbon.
8. In the process of removing an adhering aqueous film or layer from a metal surface by the steps of displacing said adhering aqueous film or layer on a metal surface with an organic solvent composition and removing said organic solvent from said metal surface, the improvement which comprises utilizing as said organic solvent composition, a composition consisting essentially of an organic water-immiscible solvent selected from the group consisting of an organic water-immiscible solvent having a density of less than 0.9 gm./ml. and a mixture of miscible organic water-immiscible solvents, said mixture having a density of less than 0.9 gm./ml., containing from 0.1 to 10 percent of a monocarboxylic acid having an average of from seven to 12 carbon atoms selected from the group consisting of 1) alkanoic acids, 2) phenylalkanoic acids, 3) alkylphenylalkanoic acids and 4) mixtures thereof and from 0.1 to 8 percent of an alkylamine selected from the group consisting of alkylamines having from six to 10 carbon atoms and mixtures of alkylamines having an average of from six to 10 carbon atoms, the average sum of the carbon atoms in said acid and said alkylamine being from 15 to 17.