Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Liquid composition
Reexamination Certificate
1998-11-05
2001-02-20
DelCotto, Gregory R. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Liquid composition
C510S245000, C510S254000, C510S433000, C510S435000, C510S499000
Reexamination Certificate
active
06191094
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an aqueous cleaning composition and to a method of using same to clean substrates. More particularly, this invention relates to an alkaline, aqueous cleaning/degreasing composition containing a particular combination of surfactants and to a method of using such composition to remove industrial-type soils from substrate surfaces.
Many industries, such as, for example, automobile parts repair and replacement services and the like, require that component mechanical parts be cleaned prior to inspection, repair, or replacement thereof. Generally, such parts have been exposed to various contaminants such as dirt, grease, oil, ink and the like, which must be removed for effective repair or service.
A variety of metal cleaners have been used to clean such mechanical parts. For example, solvent-based metal cleaners have been used which contain either halogenated or non-halogenated hydrocarbons. Aqueous-based, highly alkaline detergent systems have also been used to clean metal parts. However, the use of such solvent-based or aqueous-based cleaners has raised environmental and/or worker safety concerns.
For example, although halogenated hydrocarbon solvents such as chlorofluorocarbons (CFCs), trichloromethane, methylene chloride and trichloroethane (methyl chloroform) have been widely used in industry for metal cleaning, the safety, environmental and cost factors associated with their use coupled with waste disposal problems are negative aspects of the use of such solvents. A world-wide and U.S. ban on most halogenated solvents is soon in the offing by virtue of the Montreal Protocol, Clean Air Act and Executive and Departmental directives.
Non-halogenated hydrocarbon solvents such as toluene, Stoddard solvent and like organic compounds such as ketones and alcohols are generally flammable and highly volatile and have dubious ability to be recycled for continuous use. These factors, along with unfavorable safety, environmental and cost factors, make the non-halogenated hydrocarbon solvents unattractive for practical consideration. For example, the most useful organic solvents, classified as volatile organic compounds (VOCs), pollute the atmosphere, promote formation of a toxic zone at ground level, and add to the inventory of greenhouse gases.
Aqueous cleaning systems have been developed to overcome some of the inherent negative environmental and health aspects associated with the solvent-based cleaning systems. Unfortunately, aqueous cleaning systems also have drawbacks.
For example, aqueous cleaners containing sodium hydroxide or organic solvents such as alkanolamine, ethers, alcohols, glycols and the like, tend to be exceedingly alkaline, i.e., having pHs of 13 and above. These exceedingly alkaline aqueous solutions are highly corrosive to metal surfaces, highly toxic and can be dangerous to handle, thus requiring extreme safety measures to avoid contact with the skin. The organic solvent-containing aqueous cleaners have the toxicity and environmental problems discussed previously herein.
Although the exceedingly alkaline aqueous cleaners have the aforementioned drawbacks, it has been most difficult to obtain an aqueous detersive solution which has a moderate pH (i.e., less than about 12.0) and which is effective in removing grease and oil contaminants from metal substrates, e.g., metal engine parts, and which would not be corrosive to the metal substrates.
A primary object of this invention is to provide an alkaline aqueous cleaning composition which has a moderate pH and which effectively removes industrial-type soil contaminants from substrates.
Another object of this invention is to provide an alkaline aqueous cleaning composition having a moderate pH and which effectively removes industrial-type soil contaminants from a metal substrate without being excessively corrosive to the metal substrate.
A further object of this invention is to provide an alkaline aqueous cleaning composition having a moderate pH and which effectively removes industrial-type soil contaminants from a substrate, wherein the cleaning composition is not irritating to human skin and is less toxic upon accidental ingestion than are organic-based solvent systems.
Still another object of this invention is to provide a method of cleaning substrates by means of an alkaline aqueous cleaning composition having the properties described in the foregoing objects.
These and other objects which are achieved according to the present invention can be readily discerned from the following description.
SUMMARY OF THE INVENTION
The present invention is based in part on the discovery that the presence in an alkaline aqueous composition of a surfactant mixture composed specifically of an ethoxylated C
12-14
alkanol surfactant having an HLB at 25° C. of from 8 to 12 and at least one aminocarboxylic acid surfactant of formula (I) hereinbelow will provide the aqueous alkaline composition with excellent cleaning abilities, particularly with respect to removing industrial-type soil contaminants from substrates such as plastic and metal substrates. This is true even when the aqueous alkaline composition is moderately alkaline.
The present invention is further based on the discovery that at a particular active-concentration ratio relative to one another, the ethoxylated C
12-14
alkanol surfactant and the aminocarboxylic acid surfactant will have a synergistic effect on the industrial-soil removing properties of the aqueous cleaning composition.
Accordingly, one aspect of the present invention is directed to an aqueous alkaline cleaning composition for cleaning a substrate contaminated with industrial-type soil contaminants, containing:
(i) an aqueous portion and
(ii) an active-ingredient portion composed of:
(A) an alkalinity-providing agent in an amount sufficient to provide the aqueous cleaning composition with an alkaline pH;
(B) a surfactant mixture containing
(a) an active concentration of an ethoxylated C
12-14
alkanol surfactant having an HLB value at 25° C. of from 8 to 12, and
(b) an active concentration of at least one aminocarboxylic acid surfactant of the general formula:
R—N(H)—R′ (I)
wherein R is a straight or branched chain aliphatic organic group having from 10 to 20 carbon atoms, preferably from 12 to 18 carbon atoms, and R′ is a straight or branched chain carboxylic acid having from 1 to 7 carbon atoms, preferably from 2 to 4 carbon atoms;
wherein the active concentration of surfactant (a) and the active concentration of surfactant (b) are such as to render the aqueous cleaning composition capable of removing at least a substantial portion of the contaminants from the substrate.
A further aspect of this invention is directed to a non-aqueous cleaning composition composed of the active-ingredient portion of the aqueous cleaning composition. Such non-aqueous cleaning composition can be combined with an aqueous medium to form the aqueous cleaning composition of this invention.
Still another aspect of this invention is directed to the surfactant mixture used in the active-ingredient portion of the aqueous cleaning composition of this invention.
A further aspect of the present invention is directed to a method of cleaning a substrate contaminated with industrial-type soil contaminants, involving the steps of:
(1) providing the aqueous cleaning composition of this invention, and
(2) contacting the contaminated substrate with the aqueous cleaning composition for a period of time sufficient to remove at least a substantial portion of the contaminants from the substrate.
One advantage of the present invention is that it provides an aqueous cleaning composition which, even at a moderately alkaline pH, is capable of effectively removing industrial-type soil contaminants from a substrate.
Another advantage of the present invention is that it provides a surfactant combination which renders the aqueous cleaning composition capable of effectively removing the industrial-type soil contaminants from the substrate.
Still another advantage of the prese
Cala Francis R.
Reynolds Richard A.
Church & Dwight & Co., Inc.
Delcotto Gregory R.
Fishman Irving M.
LandOfFree
Aqueous cleaning composition for cleaning substrates and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aqueous cleaning composition for cleaning substrates and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aqueous cleaning composition for cleaning substrates and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2567625