Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Patent
1996-09-11
1998-03-31
Hertzog, Ardith
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
510238, 510245, 510247, 510253, 510254, 510269, 510365, 510421, 510423, 510433, 510434, 510477, 510488, 510494, 510496, 510497, 510504, 510506, C11D 304, C11D 320, C11D 1002, C11D 1700
Patent
active
057338590
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to cleaning compositions for hard-surfaces. More specifically, compositions are described which give optimal performance in removing limescale stains and encrustations while ensuring appropriate surface safety, especially when used for cleaning and descaling metal surfaces.
BACKGROUND
Tap water contains a certain amount of solubilized ions which upon water evaporation eventually deposit as salts such as calcium carbonate on surfaces which are often in contact with said water, resulting in an unaesthetic aspect of said surfaces. This limescale formation and deposition phenomenon is even more acute in places where water is particularly hard.
It is well known in the art that limescale can be removed chemically with acidic solutions, and a great variety of acidic cleaning compositions have been described for this purpose.
However, in many instances acidic compositions may cause the problem that the acids which are used damage the surfaces being treated. In particular, some corrosion/staining may occur when metal surfaces such as aluminium, chromed steel or stainless steel are treated with such acids.
It is therefore an object of the present invention to obviate this issue in providing a cleaning composition for the removal of limescale, said composition possessing a superior limescale removing capacity while being also safe to metal surfaces.
It has now been found that for an acid which has a first pKa not exceeding 5, surface safety is improved without compromising on limescale removing capacity by combining said acid or mixtures thereof with maleic acid, in appropriate ratios. Indeed, it has been found that the compositions of the present invention comprising maleic acid and such an acid in appropriate ratios are significantly safer to metal surfaces than the same compositions without maleic acid, while being also particularly effective in removing limescale.
An advantage of this invention is that said compositions are also safe to other surfaces besides metal surfaces including synthetic surfaces.
U.S. Pat. No. 3,277,008 discloses solid compositions suitable for use with water to form aqueous solutions for descaling the internal metal surfaces of the jacket of the glass-lined jacketed equipment. Said compositions comprise a cleaning agent such as sulfamic or hydrochloric acid, maleic acid and a corrosion inhibitor. Surfactants are not disclosed.
DE-3,822,658 discloses compositions useful for removing oxide layers from metal surfaces like copper or bronze. Said compositions comprise a mineral acid for example nitric acid, a carboxylic acid such as maleic acid, phosphonic acid and thioureas. Nonionic surfactants are disclosed as optional ingredients without specifying appropriate amounts.
EP-A-0,496,188 discloses a composition comprising nonionic surfactants together with maleic acid whereby good limescale removal is provided. Citric acid is disclosed together with maleic acid in some of the examples. But citric acid is not effective in removing limescale at low pH.
SUMMARY OF THE INVENTION
The present invention is an aqueous cleaning composition having a pH of from 0.1 to 4.5, suitable for removing limescale from hard-surfaces, comprising from 0.01% to 30% by weight of the total composition of a surfactant or mixtures thereof, maleic acid and an acid which has a first pKa not exceeding 5, with the exception of citric acid, or mixtures thereof, in a weight ratio of maleic acid to said acid such that surface safety is improved.
The present invention also encompasses a process of treating hard-surfaces, especially metal surfaces, wherein a composition according to the present invention is used in its neat or diluted form.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graphical representation of the effect on surface appearance of an aqueous solution containing about 3% sulfamic acid containing various levels of maleic acid.
DETAILED DESCRIPTION OF THE INVENTION
The compositions according to the present invention are designed for removing limescale or soi
REFERENCES:
patent: 3277008 (1966-10-01), Heit
patent: 3915633 (1975-10-01), Ramachandran
patent: 3954630 (1976-05-01), Ramachandran
patent: 4351673 (1982-09-01), Lawson
patent: 4381950 (1983-05-01), Lawson
patent: 4749508 (1988-06-01), Cockrell, Jr. et al.
patent: 4959105 (1990-09-01), Neidiffer et al.
patent: 5656580 (1997-08-01), Carrie et al.
Carrie Michel Jean
Koenig Axel
Vos Eddy
Aylor Robert B.
Hertzog Ardith
The Procter & Gamble & Company
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