US3337471A

US3337471A - Non-corrosive dry-cleaning composition

Info

Publication number: US3337471A
Application number: US439070A
Authority: US
Inventors: Sheldon G Levy; Donald A Baker; Roger F Monroe
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1965-03-11
Filing date: 1965-03-11
Publication date: 1967-08-22
Anticipated expiration: 1984-08-22
Also published as: BE700834A; NL6709802A; GB1123858A; DE1617079B2; DE1617079A1

Description

United States Patent 3,337 471 N ON-CORROSIVE DRY-CIZEANIN G COMPOSITION Sheldon G. Levy, Donald A. Baker, and Roger F. Monroe, Midland, Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Filed Mar. 11, 1965, Ser. No. 439,070 8 Claims. (Cl. 252'-153) The present invention relates to a novel composition ofmatter and to a process for preventing the corrosion of metals in contact therewith.

It has now been found that certain detergents used widely in the dry-cleaning of fabrics cause deterioration or corrosion of the metal in contact therewith. The marked increase in the use of dry-cleaning solvents containing detergents which remain in the system for more than one cycle, as well as the recent advent of the coinoperated machines, has necessitated the use of many new detergents. Due to lack of control over and the longer retention of these detergents, a problem has arisen which was not foreseen, to wit: the corrosion of the metals, particularly copper, of the machines. This corrosion of copper shows up as a green coloration to the solvent system. The sales appeal is lessened when the coin-operated machine customer observes this green coloration of the solvent. Further, the corrosion is not desirable from a structural standpoint, nor from. the chance fading into (stain) light-colored clothes and fabrics.

It has now been discovered that if a small amount of a benzotriazole is dissolved in the dry-cleaning solvent system containing the detergent the corrosion of the metal surfaces, particularly copper, is prevented, and thus the green coloration of the solvent is prevented. In accordance with the present invention it has been found that when a benzotriazole is added in an amount of from about 10 to 250 or more parts per million parts of use strength or dilution solvent-detergent system the corrosion of the metal parts in contact with this system is prevented. While it is to be understood that more than 250 parts of the benzotriazole compound can be employed at use dilution, there is little if any advantage over that achieved with 250 or less parts. It has been found that about 50 parts of the benzotriazole compound will prevent corrosion under normal conditions as well as short periods of more severe operation. It is to be understood that the nihibitor can be made up as a concentrate of dry-cleaning solvent-drycleaning detergent and about 2000 p.p.m. of inhibitor, which concentrate can be employed to prepare solvent for use in the dry-cleaning operation. The inhibitor may be added to the solvent before the addition of the detergent, simultaneously therewith or after the solvent has been added. Further, it is to be understood that the inhibitor may and preferably should be replenished from time to time, particularly when fresh or makeup solvent and/ or makeup detergent is added to the solvent-detergent system.

Ii has also been found advantageous to maintain at least 10 parts of the triazole compound in solution at all times even after substantial depletion of the detergent. For while it is believed that the triazole compounds of the present invention coat out on the metal or form some complex which prevents attack by the corrosive detergentsolvent-moisture combination, the coating is susceptible to loss of integrity and only if the solvent-detergent syswherein R represents an alkyl radical having from 1 to 18 carbon atoms, n represents an integer from 0 to 4, and preferably the total number of carbon atoms in the R's not exceeding about 12.

The dry-cleaning solvents which are commonly employed in the industry and are compatible with the inhibitor are the chlorinated hydrocarbons, such as, for

example, perchloroethylene, carbon tetrachloride, as Well as the petroleum naphthas, Stoddards solvent, and the like.

It is to be understood that most amine, phosphate and sulfonate-based detergents have been found to promote the corrosion of metals (particularly copper) by the solvent-detergent system. Representative of the types of detergents which have been found to be particularly corrosive in these systems are the petroleum sulfonates, the alkylamine alkylbenzene-sulfonates, such as isopropylamine benzene sulfonate, the aryl phosphate ester-ethylene oxide adducts, alkylphenol-polyethylene oxide adducts, nonyl phenol condensed with four to nine moles of ethylene oxide, and the ammonium dodecyl-benzene sulfonates.

The following examples illustrate the present invention but are not to be construed as limiting.

Example 1 Nine bottles were prepared, each containing ml. of a commercial grade dry-cleaning solvent (perchloroethylene containing the manufacturers stabilizer system for the solvent). To each of three bottles was added a precleaned 2 /2 x /2" x 0.064" strip of copper weighed to the nearest 0.1 mg. To another three bottles was added a like-size strip of iron and to the final three bottles was added a similar size strip of zinc. Each set of three bottles was further prepared as follows: to two of each set of three was added 2.5 percent by volume of an alkyl aryl phosphate ester ethylene oxide adduct detergent used commercially in dry-cleaning. To the third bottle of each set of three, nothing was added. This bottle served as a check to show the non-corrosive nature of the solvent. To one of the two bottles of each set to which the detergent was added, there was also added 50 parts by weight of benzetriazole per million parts by weight of solvent-detergent. As indicated, the other two sets of three bottles containing the zinc or iron strips were similarly prepared. Upon completion of the preparation, the nine bottles of solvent were all placed in a constant-temperature oven held at 3 120 F. for 30 days, after which time the bottles were removed, the strips of metal cleaned and reweighed. From the loss of weight the percent loss was calculated. These data are set down in the following table:

[100 ml. perchloroethylene, 120 F., 30 days] Metal 0.. .1 Zn .1 Fe

Percent Detergent,

Wt. Diti.

Percent Vol.

Benzotriazole, p.p.m.

OOOWOOOMOWUJ Example 2 In another series of tests to further demonstrate the utility of the present invention, 0.25 volume percent of oleic acid was added to each of three bottles containing 100 ml. of perchloroethylene (containing the manufacturers solvent stabilizers) and a strip of copper of the same size as employed in Example I placed in each bottle. To one jar labeled B was added 100 p.p.m. (vol.) of benzotriazole. To bottle B and one labelled A was added 1 percent by weight of a commercial isopropylamine benzene sulfonate dry-cleaning detergent. The third bottle labeled C was left with only the acid, solvent and copper strip. All three bottles were placed in a constant temperature oven held at 120 F. for 24 hours. At the end of this period the bottles were removed and examined visually for evidence of coloration. Bottle A had a green color in the liquid and the metal was patina and greenish in color. Neither bottles B nor C had any evidence of color and the metal remained bright and unaifected.

We claim:

1. A dry-cleaning composition containing a dry-cleaning solvent stabilized against metal corrosion and solvent decomposition, a dry-cleaning detergent selected from the group consisting of anionic and nonionic organic detergents and from about to about 100 parts by weight of a benzotriazole soluble in said solvent and having the formula:

wherein R represents an alkyl radical having from 1 to 18 carbon atoms and n represents an integer from O to 4.

3. Perchloroethylene stabilized against metal catalyzed deterioration containing, an alkyl amine alkylbenzene sulfonate dry-cleaning detergent and from 10 to 250 parts of benzotriazole per million parts of Perchloroethylene and detergent.

3. Dry-cleaning naphtha containing, an alkyl amine alkylbenzene sulfonate dry-cleaning detergent and from 10 to 250 parts of benzotriazole per million parts of naphtha and detergent.

4. Perchloroethylene stabilized against metal catalyzed deterioration, containing an alkyl amine alkylbenzene sulfonate dry-cleaning detergent and 50 parts of benzotriazole per million parts of perchloroethylene and detergent.

5. Perchloroethylene stabilized against metal catalyzed deterioration, containing an aryl phosphate ester ethylene oxide adduct dry-cleaning detergent and from 10 to parts of benzotriazole per million parts of perchloroethylene and detergent.

6. Perchloroethylene stabilized against metal catalyzed deterioration, containing an aryl phosphate ester ethylene oxide adduct dry-cleaning detergent and 50 parts of benzotriazole per million parts of perchloroethylene and detergent.

7. A method for stabilizing a dry-cleaning solvent system containing a dry-cleaning detergent selected from the group consisting of anionic and nonionic organic detergents and protecting the metal parts of the machinery used to clean fabrics and to process the detergent-solvent system which consists of maintaining dissolved in the said system from 10 to 250 parts per million parts of system of a benzotriazole having the formula:

References Cited UNITED STATES PATENTS 2,877,188 3/1959 Liddell 252-390 XR 2,941,953 6/1960 Hatch 252390 XR 3,162,604 12/1964 Michaels 252-171 FOREIGN PATENTS 582,455 9/1959 Canada.

LEON D. ROSDOL, Primary Examiner.

J. T. FEDIGAN, Assistant Examiner,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,337 ,471 August 22 1967 Sheldon G. Levy et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 52, after "weight" insert per million parts of solvent detergent Signed and sealed this 23rd day of December 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. E.

Attesting Officer Commissioner of Patents

Claims

1. A DRY-CLEANING COMPOSITION CONTAINING A DRY-CLEANING SOLVENT STABILIZED AGAINST METAL CORROSION AND SOLVENT DECOMPOSITION, A DRY-CLEANING DETERGENT SELECTED FROM THE GROUP CONSISTING OF ANIONIC AND NONIONIC ORGANIC DETERGENTS AND FROM ABOUT 10 TO ABOUT 100 PARTS BY WEIGHT OF A BENZOTRIAZOLE SOLUBLE IN SAID SOLVENT AND HAVING THE FORMULA: