US3431209A

US3431209A - Solvent degreasing,self-emulsifying cleaning composition

Info

Publication number: US3431209A
Application number: US575929A
Authority: US
Inventors: Myer Rosenfeld
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1966-08-26
Filing date: 1966-08-26
Publication date: 1969-03-04
Anticipated expiration: 1986-03-04
Also published as: CA770083A

Description

4 Claims ABSTRACT OF THE DISCLOSURE A self-emulsifying cleaning composition for removing undesired coatings from metallic and painted surfaces comprising: cyclohexanol; ethylene glycol monobutyl ether; diethylene triamine-diacetone condensate; diglycol oleate; ethanolamine oleate; surface active amine alkyl aryl sulfonate; sorbitan oleate and lauric acid mixed with an organic solvent.

This is a continuation-in-part of application Ser. No. 391,341, filed Aug. 21, 1964 now abandoned for Metal Cleaning Composition.

This invention relates to improvements in one class of self-emulsifying cleaning compositions for removing oils, greases, asphalt, tars and rust preventive compounds, other than wax type, from metallic and painted surfaces.

Cleaning compositions of this type are formulated as additive concentrates containing the condensate of diethylene triamine and diacetone alcohol, as disclosed in U.S. Patent 2,616,856, mixed with surfactants such as diglycol oleate and ethanolamine oleate to improve its solubility in oil.

A particularly effective solvent degreasing cleaner containing the above ingredients forms the subject matter of U.S. Patent 3,146,207, issued jointly to Myer Rosenfeld, the applicant herein, and to Robert E. Wagner, Jr., said cleaner being highly successful for removing lithium base greases that are very resistant to water and organic solvent removal. This previous cleaner was also equally effective for the removal of aged preservative type compounds, sodium and calcium base greases, tars, asphalt and various other soils. The cleaner also displayed improved emulsifying properties whereby stable emulsions were readily obtained with only a small amount of agitation.

The previous additive concentrate as disclosed in the aforementioned patent contained the following ingredi cuts in parts by volume:

Parts Cyclohexanol 1 Ethylene glycol monobutyl ether 0.5 Diethylene triamine-diacetone condensate 0.25 Diglycol oleate 1 Ethanolamine oleate 2.5-4.5 Surface active amine sulfonate 0.5-3 Sorbitan oleate 0.5-1.5

The above parts by volume were mixed with 100 parts by volume of an organic solvent to produce the final cleaning composition.

Although this previous composition has demonstrated the desired cleaning action against thick, resistant layers of grease, it was found to be corrosive to galvanic couples of magnesium, aluminum and steel. Further investigation of the various ingredients separately and in various combinations indicated that the surface active amine sulfonates used in the cleaner, although they olfset some of the nited States Patent 3,431,209 Patented Mar. 4, 1969 corrosion inherent in the rest of the composition, were chiefly responsible for the galvanic corrosion action.

The reason advanced for the cleaners corrosion problem was due to the difference in chemical potential set up between portions of metal which were substantially covered with adsorbed sulfonate and portions of metal which remain uncovered with adsorbed sulfonate.

Therefore, it is the object of this invention to provide an improved cleaning composition which can be used on installations and equipment in which light weight metals of magnesium and aluminum are present, even when galvanically coupled to each other or to steel.

Another object of this invention is to provide a corrosion inhibitor in the cleaner which will not interfere with any of the performance requirements previously introduced into the cleaner but which will overcome corrosion due to galvanic action.

In accordance with the invention, the solvent cleaner described above is improved considerably by incorporating lauric acid therein in concentrations of from about one to 10 grams per ml. of final cleaner. The presence of gram lauric acid in the cleaner has been found to be effective in preventing corrosion. Furthermore, its presence will not interfere with any of the performance requirements built into the cleaner. In accordance with the present findings, lauric acid will afford the necessary protection if the amine sulfonate is present in concentrations not exceeding 1 part in 7.75 parts of additive concentrate by volume. The improved cleaning composition of this invention may be used for cleaning magnesium and aluminum parts, even when galvanically coupled together or to steel, Without any detectable corrosion observed by its use.

That the invention is a fortuitous one may be explained from the various fatty acids (stearic, palmitic, myristic) which were tested but which were found to lessen the cleaning action. Fatty acid molecules having alkyl radicals of 13-17 carbon atoms were found to interfere with the removal of road tar. Also, shorter alkyl chains of less than that of the lauric acid molecule are ineffective for inhibiting galvanic corrosion because it is believed that reduced surface activity prevents penetration of the molecule into narrow channels between galvanically coupled metals.

In the practice of the present invention the addition of lauric acid in concentrations of 1 gram to 10 grams per 100 ml. of final composition is effective for inhibiting corrosion. When the surface active sulfonates are used in relatively low concentrations, as shown in Examples 1, 3, 5, 7, 8 and 9 in the table below, about 1 gram lauric acid is found effective for this purpose. In other examples which include about 1% sulfonate, not less than about 2 grams of lauric acid per 100 ml. of cleaning composition are needed to overcome corrosion. In all permissible sulfonate concentrations, however, up to grams of lauric acid may be included without affecting the cleaning ability of the present composition.

The surface active amine sulfonates which are useful in the practice of the present invention have been designated as (l) the amine salt of alkyl aryl, sulfonate type, such as Emcol HB manufactured by Witco Chemical Co., Inc. and (2) aromatic acyclic amine sulfonate, such as Aromol 10 manufactured by Burkart-Schier Chemical Co. More specifically, the amine sulfonate may comprise an ammonium or amine dodecylbenzene sulfonate in which the dodecyl chain comprises a mixture of branched chains. Other sulfonates may include mixtures of the above compound with those containing the ammonium or amine n-dodecyl benzene sulfonate, and such a mixture may be for example in the weight ratio of 1:4, respectively.

l1lustrative of compositions for which successful galevidence of corrosion on the aluminum and magnesium panels.

ADDITIVE CONCENTRATE-PARTS BY VOLUME Ingredients 1 2 3 4 5 6 7 8 9 Cycloliexanol 1.0 1.0 1.0 1.0 1.0 1.0 1.. 1.0 1.0 Ethylene glycol monobutyl ether"... 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Diethylene triamine-diacetorie condensate 0. 25 0. 25 0. 25 0. 25 0.25 0. 25 0. 25 0. 25 0. 25 Diglycol oleate 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 Ethanolamine oleate 3. 5 3. 5 3. 5 2. 5 2. 5 4. 5 4. 5 2. 5 4. 5

Amine sulfonate 0.5 1.0 .75 1.0 0.5 1.0 0.5 .75 .75 Sorbitan monoolcate- O. 5 0. 5 1. 0 1. 5 0. 5 1. 0 1. 5 0. 5 1. 5

Total parts by volume 7.25 7.75 8.0 7.75 6.25 9.25 9.25 6.5 9.5

The diethylene triamine-diacetone condensate is It will be apparent therefore from the foregoing descripformed by adding 30.3 parts of diethylene triamine droption of this invention that the improved composition dewise with vigorous stirring (air stirrer or other sparkscribed herein provides satisfactory cleaning for systems free stirrer) to 69.7 parts of diacetone alochol. The adcontaining aluminum, magnesium and steel alone or dition is conducted at a rate so that the temperature of galvanically coupled. the mixture does not exceed 34 C. at any time. It has The compositions shown are only exemplary and varbeen found advantageous to carry out the addition at a ious modifications can be made within the scope of inrate of about 2 to 3 milliliters of diethylene triamine vention as defined in the appended claims. per minute for every liter of diacetone alcohol used in What is claimed is: the reaction. .1. A cleaning composition consisting essentially of:

The ethanolamine olate may be conveniently prepared (A) the following additive concentrate in parts by in high flash coal tar naphtha by mixing at room temv lume perature the following ingredients in the order listed:

Cyclohexanol 1 .0 Percent by volume Ethylene glycol monobutyl ether 0.5 High flash coal tar naphtha 50.0 Diethylene triamine-diacetone condensate 0.25 Mono-ethanolainine 7.7 Diglycol oleate 1.0 Oleic acid 42,3 Ethanolamine oleate 2.5-4.5 Surface active amine alkyl aryl sulfonate 0.5-4.0 In preparing the present cleaning composition, the ad- Sorbltan oleate 054-5 ditive concentrate in parts by volume is added to '100 (B) a solvent of about 70 parts by volume high flash parts by volume of a suitable solvent. A solvent mixture coal tar na htha and about 30 arts kerosene 8 id of 70 parts by volume of high flash coal tar naphtha p a o solvent being present in 100 parts by volume, and (minimum flash point 100 F.) and 30 parts by volume (C) lauric acid in a concentration of about '1 to about of kerosene may be employed to better advantage. Other 40 10 grams er 100 ml of said additive cone ntrat solvents which may also be used are Solvesso 100 and and Said i e e Panasol ANI. The lauric acid is then dissolved in the 2. A cleaning composition in accordance with claim 1 33} gg gg m about 1 to 10 grams/100 of wherein said surface active amine alkyl aryl sulfonate is p ammonium dodecylbenzene sulfonate.

GALVANIC CORROSION TEST 3. A cleaning composition in accordance with claim 1 in which said sulfonate is present in a concentration of Corrosion to galvanically coupled metals was tested about 1 to Part P Volume and sa1d launc acld by sandwiching a magnesium panel of larger area between presept m a concentmnoil of about 1 gram per 100 an aluminum panel and a steel panel, FS1020 cold rolled of sa1d concerftrate and E; l steel. The panels were polished with No. 50 aluminum cleaPmg composlflon accordance wlth clalm 1 oxide cloth and with NO 320 Carborundum paper. The in which said sulfonate is present in a concentration of panels were then Washed with 95% ethyl alcohol and 'f 1 part y volume and sa1d launc acld pmseflt dried with paper toweling. The magnesium panel was in a COHCBIIIIBIIOII of about 2 grams per 100 ml. of said then placed between the aluminum and the steel panel, concentrate and sa1d solvent and three panels were then tied together with cotton R f string. The panels were placed in a glass container and e erences covered with cleaning composition. Four sets were used UNITED STATES ATENTS for each composition tested. After 24 hours the panels 3 14 07 8/1964 Rosenfeld at a] were removed from the q p washed with water, 3,215,945 11/5955 Mankowick 252 153 With c h a d dried. Each panel was then ex- 2,281,576 5/1942 cook amined for pitting, for other types of corrosion and for discoloration. Cleaning compositions which contained LEON D. ROSDOL, Primary Examiner. the additive concentrate of Examples 1-9 and lauric acid B BETHS A therein in amounts of about 1-10 grams/ ml. of com- 55 Exammer' position were capable of inhibiting galvanic corrosion. When the identical cleaning composition was tested without the presence of lauric acid therein, there was visual U.S. Cl. X.R.