Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – With oxygen or halogen containing chemical bleach or oxidant...
Reexamination Certificate
2001-06-12
2003-04-15
Gupta, Yogendra N. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
With oxygen or halogen containing chemical bleach or oxidant...
C510S310000, C510S318000
Reexamination Certificate
active
06548470
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a bleaching compositions which can be used to bleach various surfaces including but not limited to, hard-surfaces as well as fabrics, clothes, carpets and the like.
BACKGROUND OF THE INVENTION
Commonly encountered liquid aqueous cleaning compositions for removal or cleaning stains on fabrics and/or hard-surfaces may comprise a bleaching agent. A number of bleaching agents are known in the art. Halogen bleaches whilst being extremely effective bleaching agents, often also present a number of drawbacks which can sometimes dissuade a consumer from choosing the halogen-containing product. For example halogen bleaches, especially chlorine bleaches, emit a pungent odour during and after use (e.g., on consumer hands and/or surfaces treated therewith) which some consumer find disagreeable.
Furthermore, it is known in the art that halogen bleach-containing compositions (typically hypochlorite) are relatively aggressive to fabrics and may cause damage when used in relatively high concentration and/or repeated usage. In particular the consumer may perceive damage to the fabric itself (e.g. loss of tensile strength) or damage to the colour intensity of the fabric. While colour and fabric damage may be minimised by employing milder oxygen bleaches such as hydrogen peroxide or hydrogen peroxide generating bleaches, the bleach performance characteristics of such peroxygen bleaches are much less desirable than those of the halogen-containing bleaching agents. Therefore, liquid aqueous activated peroxygen bleach-containing compositions have been developed containing activators, i.e., compounds which enhance peroxygen bleaching performance. However these bleaches do not perform as well as hypohalite bleaches in stain removal.
Peroxycarboxylic acid (peracid) bleaches are known in the art. The Applicant has found that such bleaches, in this instance, are particularly useful as they do not present the disadvantages of hypochlorite bleaches and are better performing bleaching agents than the oxygen bleaches. However generally peracid bleach-containing compositions have stability problems as the peracid prematurely begins to degrade. This premature degradation of the peracid is believed to be due to the presence of trace amounts of metal ions in the formulation which may catalyse the further degradation of the peracid.
The present invention thus provides a bleaching composition which is stable, safe to the surfaces treated and delivers improved bleaching performance when used in laundry applications and/or in any household application (e.g. bleaching/disinfecting of hard-surfaces).
Furthermore, it is believed that the solubility of the particulate pre-formed peracid is affected by the level of hardness ions. By ‘hardness ions’ it is meant ions that are present in water and form insoluble salts that precipitate from solution. The most predominant hardness ions are calcium and magnesium ions. The water may be either water used to prepare the composition of the present invention or may be the wash water into which the composition of the present invention is dispensed. Thus, it is another object of the present invention to prevent or at least reduce the precipitation of the peracid from the composition.
The compositions according to the present invention may be useful in any laundry application, e.g., as a laundry detergent or a laundry additive, and when used as a laundry pre-treater. A particular advantage of the compositions of the present invention is that they are suitable for the bleaching of different types of fabrics including natural fabrics, (e.g., fabrics made of cotton, and linen), synthetic fabrics such as those made of polymeric fibres of synthetic origin (e.g., polyamide-elasthane) as well as those made of both natural and synthetic fibres. For example, the bleaching compositions of the present invention herein may be used on synthetic fabrics despite a standing prejudice against using bleaches on synthetic fabrics, as evidenced by warnings on labels of clothes and commercially available bleaching compositions like hypochlorite-containing compositions.
Another advantage of the bleaching compositions according to the present invention is that they can be used in a variety of conditions, i.e., in hard as well as soft water and in either neat or diluted form. More particularly, it has been found that the liquid aqueous compositions of the present invention find a preferred application when used in their diluted form in any application and especially in any conventional laundry application. Indeed, upon dilution (typically at a dilution level of 20 ml/L or more (composition:water)) the compositions of the present invention become less acidic, e.g., from a pH of about 1.5 to about 6.5 or more. The compositions according to the present invention although delivering effective bleaching performance in their neat form surprisingly exhibit further enhanced bleaching performance in their diluted form. Actually, this “pH jump” effect allows to formulate acidic liquid aqueous compositions (i.e. pH below 7, preferably below 3 and more preferably below 2) which are physically and chemically stable upon prolonged periods of storage and which deliver outstanding bleaching performance under diluted usage conditions.
Yet another advantage of the compositions of the present invention is that they exhibit also effective stain removal performance on various stains including enzymatic stains and/or greasy stains.
SUMMARY OF THE INVENTION
According to the present invention there is provided a liquid detergent composition comprising a pre-formed particulate peroxy carboxylic acid containing at least one aromatic group and a co-agent selected from the group consisting of organic acid, homo and copolymer of acidic monomers and mixtures thereof.
In another preferred aspect of the present invention there is provided a liquid bleaching product comprising a first composition comprising a peroxy carboxylic acid containing at least one aromatic group and a second composition comprising a surfactant wherein the product is packaged such that first and second compositions are separated from each other.
The present invention further encompasses methods of bleaching a surface with a composition according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Liquid Bleaching Composition
The compositions according to the present invention are liquid and preferably aqueous. Thus the composition preferably has a water content of from 10% to 99%, more preferably from 30 to 95%, more preferably 40 to 90% by weight of the composition.
Where the composition according to the present invention is liquid is preferably has a pH of below 7. Preferably, the pH of the compositions according to the present invention is from 1 to 6, more preferably from 1 to 5, even more preferably from 2 to 4. Formulating the compositions according to the present invention in the acidic pH range is critical to the chemical stability of the compositions according to the present invention. The pH of the composition is preferably below the pKa of the peracid used. It is believed that the acidic pH controls/limits the formation of highly reactive species which are unstable in acidic medium upon storage, and thus contributes to the stability of the compositions for prolonged periods of storage.
The pH of the compositions may be adjusted by any acid or alkaline species known to those skilled in the art. Examples of acidic species suitable for use herein are organic acids, such as citric acid and inorganic acids, such as sulphuric acid, sulphonic acid and/or metanesulphonic acid. Examples of alkaline species are sodium hydroxide, potassium hydroxide and/or sodium carbonate.
It has been found that the bleaching performance of the composition of the present invention is significantly improved versus the same composition but without either the peroxycarboxylic acid and/or the co-agent. In fact it has been found that a synergy has been identified that could not have been foreseen from bleaching performance dat
de Buzzaccarini Francesco
Delplancke Patrick Firmin
Gagliardini Alessandro
Scialla Stefano
Todini Oreste
Gupta Yogendra N.
McBride James F.
Miller Steven W.
Petruncio John M.
The Procter & Gamble & Company
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