EP0151114A4

EP0151114A4 - Acid based variable viscosity compositions such as corrosion and grease removers and polishers.

Info

Publication number: EP0151114A4
Application number: EP19830902583
Authority: EP
Inventors: Richard K Vitek
Original assignee: Fotodyne Inc
Current assignee: JARGOSCH, REINER; LOTT, PETER F., DR.
Priority date: 1983-07-06
Filing date: 1983-07-06
Publication date: 1985-12-05
Also published as: DE3381414D1; JPS60501817A; WO1985000379A1; EP0151114B1; EP0151114A1

Abstract

An improved, highly penetrating rust remover and/or degreaser composition for metallic surfaces, which is chemically inhibited to substantially prevent oxidation-reduction reactions with a metal substrate and limit the action of the composition to a chemical attack on corrosion. The composition is preferably a single phase dispersion and includes respective quantities of an acid such as hydrochloric acid and phosphoric acid, an organic compound containing a nitrogen, oxygen or sulfur atom such as N-(2-hydroxyethyl) oxazolidine, an alcohol or other organic solvent for grease removal, water and one or more emulsifiers (e.g., a derivative of hydrogenated tallow) for stabilizing and lowering the surface tension of the resultant composition. The compositions may be formulated as liquids or with a viscosity control agent such as a polylmer of vinyl pyrrolidone to give a paste-like consistency permitting easy use thereof on vertical surfaces. In other forms, the compositions hereof may include a mild abrasive such as activated silica gel.

Description

ACID BASED VARIABLE VISCOSITY COMPOSITIONS SUCH AS CORROSION AND GREASE REMOVERS AND POLISHERS

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is concerned with improved, acid-based corrosion, grease removal and polishing compositions for treating metallic surfaces and objects. More particularly, it is concerned with such compositions which are compounded so as to substantially prevent oxidation-reduction reactions that would normally take place at a metallic surface, and allow only acid attack of the oxides on the metal. In preferred forms, the compositions hereof may include polyvinyl pyrrolidone as a viscosity control agent and inhibitor, a derivative of hydrogen tated tallow as an emulsifier, and an N-substituted oxazolidine as an acid inhibitor. 2. Description of the Prior Art

Compositions for removing corrosion (metal oxides) from metallic surfaces and objects have long been available. Generally speaking, such materials are acid based, i.e., they rely upon an acidic attack in order to remove corrosion.

A persistent problem encountered in connection with prior corrosion removal compositions and polishes stems from the fact that oxidationreduction reactions can occur between the compositions and the underlying metal surfaces to be cleaned and decorroded. Hence, while many of these prior compositions were effective in corrosion removal and/or polishing, they often were prone to attack the metal substrate and leave the same pitted and unattractive.

Another problem with such prior compositions stems from the fact that they are ineffective as grease removers. Accordingly, if the metallic surfaces desired to be decorroded had substantial amounts of fatty organic (oil) films thereon, the effectiveness of the compositions was reduced, and the acidic and aqueous components thereof hindered in removal of corrosion. Furthermore, such solutions were of uncontrolled viscosity, either being too viscous to prevent application by spray or brush, or too low in viscosity to cling on vertical surfaces.

SUMMARY OF THE INVENTION The present invention overcomes the problems noted above, and provides greatly improved, flowable, aqueous, highly penetrating compositions of acidic pH which are effective for polishing and removal of corrosion from metallic surfaces, and also to degrease the same. The compositions of the present invention may include respective quantities of an acid, an organic compound having a nitrogen, oxygen or sulfur atom therein, an alcohol or other organic solvent, water and at least one emulsifier.

In preferred forms, the acid component is selected from the group consisting of hydrochloric, sulfuric, phosphoric, acetic, citric, nitric, boric and mixtures thereof. The acid is further preferably present at a level of from about 2% to 95% by weight, and more preferably from about 5% to 37% by weight. The organic compound is advantageously selected from the group consisting of N-substituted oxazolidines (most preferably N-(2-hydroxyethyl) oxazolidine), the p-alkyl benzyl pyridine chlorides, phenylthiourea, 2-mercaptobenzothiazole, di-orthotolyl-thiourea, pyridine, quinoline, decylamine, the dibenzyl sulf oxides, 2-butyne-1, 4-diol, 1-hexyne 3-ol, 4-ethyl-1-octyne-3-ol, decyclamine, soyaamine, octadecylamine, trimethylsoyaammonium chloride, trimethyloctadecylammonium chloride, trimethyldodecyl ammonium chloride, trimethyltallowammonium chloride, N-coco-1, 3-diaminopropane, the tetraalkylammonium bromides having an alkyl group with at least 10 carbon atoms therein, the mono-, di-, and tributylamines, hexamethylenediamine, polyvinyl pyrrolidone, 2-(bis) 2-hydroxy ethyl (amino)-1, 3-propanediol, 2-(bis)2-hydroxyethyl (amino)-methanediamine,

1,6,8-triaza-4, 10-dioxabicyclo [5,5,0] dodecane, and mixtures thereof. Such compounds should be used at a level of from about 0.01% to 20% by weight, and more preferably from about .5% to 5% by weight. The alcohol component is most preferably 1-proρanol, but other alcohols could also be employed. As used herein, other alcohols refers to an alcohol having an alkyl group with from about 1 to 10 carbon atoms, inclusive. The alcohol should be used at a level of up to 40% by weight, and most preferably at a level of about 1 to 8% by weight.

The water should be present at a level of from about 30% to 80% by weight, and most advantageously at a level of from about 50% to 80% by weight. The most preferred emulsifiers for use in the invention are selected from the group consisting of the derivatives of hydrogenated tallow (e.g., N, N', N'-tris (2-hydroxy- ethyl)-N-tallow-1, 3-diaminopropane or amine acetate hydrogenated tallow), polyoxyethylene ethers, polyoxyethylene ester alcohols, polyoxyethylene esters of mixed fatty and resin acids and mixtures thereof, although other specific types referred to hereinafter also have utility. The total amount of emulsifier present in the composition should be from about 0.1% to 15% by weight, and more preferably from about .5% to 5% by weight.

A viscosity control agent (thickener) can also be used in the compositions hereof to give variations in viscosity. Such viscosity control has heretofore proved to be difficult or impossible to obtain in acidic compositions, inasmuch as most conventional thickeners tend to flocculate at low pH. The control agents of the invention should be selected from the group consisting of polyvinylpyrrolidone and the allylamine emulsion polymers. The pyrrolidone is preferred, however, inasmuch as it also acts as a corrosion inhibitor on metallic surfaces. The viscosity control agent should be used at a level of up to about 35% by weight, and most preferably at a level of from about 0.5% to 5% by weight.

A synergistic effect is observed by the use of the mixture of polyvinyl pyrrolidone, Ethoduomeen T/13, and N-(2-hydroxyethyl)-oxazolidine as a corrosion inhibitor in preventing base metal attack, inasmuch as the attack with the preferred mixture is less than that of any of the individual corrosion inhibitors.

In further forms of the invention, a mild abrasive such as activated silica gel (at a level of up to about 10% by weight) can be employed. Perfumes and coloring agents can be added as desired. In addition the system can be modified for corrosion removal on metal surfaces having a heavy grease or oil coating by preparing a two-phase emulsified system fay the addition of toluene or related organic solvents.

BRIEF DESCRIPTION OF THE DRAWING

The single feature is a graphical representation depicting the extent of base metal attack when using a commercially available corrosion remover, 10% HCl, and the preferred corrosion removing composition of the invention.

DESCRIPTION OE THE PREFERRED EMBODIMENTS The most preferred rust removal compositions in accordance with the present, invention contain commercial hydrochloric acid, commercial phosphoric acid, 1-propanol, N-(2 hydroxyethyl) oxazolidine, water, a thickening agent, and N,N', N'-tris (2-hydroxyethyl)-N-tallow-1, 3-diaminopropane as an emulsifier. The following table sets forth the single most preferred rust removal composition, as well as ranges of use of the above identified components.

1 N,N',N'-tris(2-hydroxyethyl)-N-tallow-1,3- diaminopropane, Sold by Armak Industrial Chemical Division, Chicago, Illinois.

² Purchased from Sigma Chemical Co., St. Louis, Missouri, and reported to have a molecular weight of 360,000. The oxazolidine base metal inhibitor component of Table I is prepared by slowly adding, with mixing, 435.7 grams of formaldehyde to a beaker containing 564.3 grams of diethanolamine. After all formaldehyde is added, the mixture should be stirred for an additional hour.

In other contexts, a base metal inhibitor component can be produced as the reaction product of a lower aldehyde (i.e., containing from about 1-4 carbon atoms) and an alkanolamine (containing one or more alkyl group each having from about 2-8 carbon atoms).

In formulating the preferred composition of Table I, a beaker containing 590 grams of water is provided. Ten grams of the Ethoduomeen T/13 hydrogenated tallow emulsifier, 270 grams hydrochloric acid, 40 grams phosphoric acid, and 50 grams of 1-propanol are all added to the beaker, with continual mixing. The mixture is then heated to 50° C.; and 30 grams polyvinylpyrrolidine is slowly added thereto. Mixing is continued until all of the polymer has dissolved.

The drawing graphically illustrates the inhibition against base metal attack provided with the preferred composition of Table I. Specifically, a commercially available corrosion remover sold under the designation "Naval Jelly" was tested, along with a solution of 10% hydrochloric acid, and the preferred composition hereof. In all cases, testing conditions were identical, and the extent of attack on a base metal substrate was measured. As can be seen, the extent of such attack is very high with the Naval Jelly and hydrochloric acid, but is significantly lower with the preferred inhibitor composition of the invention.

In the case of a cleaner/polish for brass and copper, the most preferred compositions, and the ranges of use of components, are set forth below:

1'2 Same as in Table I In preparative procedures all of the components save the polyvinylpyrrolidone are simply admixed as a single phase dispersion or solution, whereupon the mixture is heated to 50°C. (although such heating is optional) and the polymer is slowly added thereto with mixing to give a thickened, viscous composition.

As noted above, a number of different materials can be employed for the various components. With respect to the emulsifier (s), surfactants available from ICI Americas, Inc., Wilmington, Delaware, and Armak Chemicals Division, Chicago, Illinois, can be employed in lieu of or in addition to the preferred tallow based emulsifiers. An exemplary list of such surfactants is provided in Table III.

The compositions of the invention are effective to remove corrosion from base metallic surfaces while substantially preventing oxidation-reduction reactions with the metal itself. In addition, grease removal is enhanced by virtue of the presence of a single phase, aqueous system. Use of the preferred single phase system also enhances the penetration of corrosion where the latter is present.

Representative metals which can be cleaned and/ or degreased using the compositions hereof include iron and steel, bronze, brass, copper, monel, nickel, chromium plated metals and aluminum.

A cleaner for tubes of boilers may also be provided by incorporting in the formulation a high foaming agent plus thickeners such as polyvinylpyrrolidone to improve wall adherence. This allows the corrosion remover to be circulated and foamed in place throughout the system by pumping or by an air blast. An additive such as Arlatone G may also be included as desired to help prevent surface rerusting. This type of corrosion remover is advantageous in that a small amount will cover a large surface area and does not require heating to permit the corrosion removal action to take place. Also, since all components are water soluble, removal of the corrosion remover can be performed by flushing water through the system.

An exemplary formulation of a- composition containing at least one foaming agent and a thickener is as follows:

1 , 2 Same as in Table I .

3 See Table III .

The preferred boiler tube cleaner is prepar ed in the same manner as the rust remover and cleaner/ polisher descr ibed above . The Arlatone G component is added initially with the HCl , oxazolidine and Ethoduomeen .

An additional use and formulation for the removal of carbonate deposits and scales for the application of salts to non-metallic surfaces can be made by using the above formulations with the deletion of the base metal corrosion inhibitor . This formulation enhances surface deposit removal without penetration to the base .

An exemplary formulation of a composi tion containing at least one degreasing agent and a thickener is as follows: Other acids such as sulfuric, nitric, phosphoric, acetic, citric, boric, or mixtures thereof can be substituted as well as other salts such as sodium perborate, tri-sodium phosphate, ammonium acetate, sodium chloride, etc.

Claims

AMENDED CLAIMS

[received by the International Bureau on 29 December 1983 (29.12.83); original claims 1.7.and 24 amended; other claims unchanged; three pages comprising the amended claims follow]

The embodiments of the invention in which an exclusive property or privilege is claimed, are defined as follows:

1. In a flowable, aqueous rust removal composition containing sufficient acid to give the composition an acidic pH, the improvement which comprises a minor amount of a viscosity control agent and a minor amount of an inhibitor in the composition to prevent base metal attack by the acid component of the composition, said control agent being in the composition selected from the group consisting of polyvinyl pyrrolidone and the allylamine emulsion polymers.

2. The composition as set forth in Claim 1, said agent being present at a level of up to about 35% by weight.

3. The composition as set forth in Claim 2 , said level being from about 0.5 to 5% by weight.

4. The composition as set forth in Claim 1, said composition including an acid selected from the group consisting of hydrochloric, sulfuric, phosphoric, nitric, acetic, boric and mixtures thereof.

5. The composition as set forth in Claim 1, said acid being present at a level from about 2 to 95% by weight.

6. The composition as set forth in Claim 5, said level being from about 5 to 37% by weight.

7. The composition as set forth in Claim 1, wherein said inhibitor includes at least one emulsifier.

8. The composition as set forth in Claim 7, said emulsifier being present at a level of from about 0.01 to 15% by weight.

9. The composition as set forth in Claim 8, said level being from about 0.5 to 5% by weight.

10. The composition as set forth in Claim 7, said emulsifier comprising a derivative of hydrogenated tallow.

11. The composition as set forth in Claim 10, said emulsifier being N,N',N' -tris-(2-hydroxyethyl)-N- tallow-1, 3-diaminopropane.

12. The composition as set forth in Claim 1, including a quantity of an organic compound having a nitrogen, oxygen or sulfur atom therein.

13. The composition as set forth in Claim 12, said compound being selected from the group consisting of N-substituted oxazolidines, the p-alkyl benzyl pyridine chlorides,phenylthiourea, 2-mercaptobenzothiazole, di-ortho-tolyl-thiourea, pyridine, quinoline, decylamine, the dibenzyl sulfoxides, 2-butyne-1, 4-diol, 1-hexyne-3-ol, 4-theyl-l-octyne- 3-ol, decylamine, soyaamine, octadecylamine, trimethylsoyaammonium chloride, trimethylocta

20. The composition as set forth in Claim 18, said alcohol being present at a level of up to about 20% by weight.

21. The composition as set forth in Claim 20, said level being from about 1 to 8% by weight.

22. The composition as set forth in Claim 1, said composition having water present at a level of from about 30 to 90% by weight.

23. The composition as set forth in Claim 22, said level being from about 50 to 80% by weight.

24. A flowable rust remover composition having a minor amount of an inhibitor to prevent base metal attack by the acid component in said composition, said composition comprising respective quantities of water, acid, an organic compound having a nitrogen, oxygen or sulfur atom therein, a viscosity control agent selected from the group consisting of polyvinyl pyrrolidone and the allylamine emulsion polymers, and said inhibitor comprising a derivative of hydrogenated tallow.

25. The composition as set forth in Claim 24, said derivative being N, N', N'-tris-(2-hydroxyethyl)-N-tallow-1, 3-diaminopropane.

26. A flowable composition comprising respective quantities of water, acid, a viscosity control agent, an emulsifier, and an N-substituted oxazolidine.

27. The composition as set forth in Claim 26, said oxazolidine being N-(2-Hydroxyethyl) oxazolidine.