Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – With oxygen or halogen containing chemical bleach or oxidant...
Reexamination Certificate
2001-05-07
2002-08-27
Delcotto, Gregory (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
With oxygen or halogen containing chemical bleach or oxidant...
C510S303000, C510S310000, C510S313000, C510S318000, C510S376000, C510S325000
Reexamination Certificate
active
06440921
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 bleaching compositions suitable for the bleaching of stains on fabrics and hard-surfaces are based on halogen bleaches, especially hypochlorite bleaches. Halogen bleaches are extremely effective bleaching agents, however they 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 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, the bleach performance characteristics of such peroxygen bleaches are much less desirable than those of the halogen bleaching agents. Therefore, liquid aqueous activated peroxygen bleach-containing compositions have been developed containing activators, i.e., compounds which enhance peroxygen bleaching performance.
It is thus an object of the present invention to provide a bleaching composition which not only delivers effective bleaching performance, when used in laundry applications and/or in any household application (e.g. bleaching/disinfecting of hard-surfaces), but is also safe to the surfaces treated, e.g. to fabrics per se and/or colours of fabrics.
Also another problem encountered when formulating bleaching compositions, is their tendency to chemical and physical instability upon prolonged periods of storage. Thus it is thus a further object of the present invention to provide bleaching composition delivering effective bleaching performance which are chemically and physically stable upon prolonged periods of storage.
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 pretreater. 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 and soft water as well as when used neat or diluted. 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 bleaching composition comprising a pre-formed peroxycarboxylic acid and a surfactant system comprising at least two surfactants.
The present invention further encompasses a process of bleaching a surface and the use of said composition.
DETAILED DESCRIPTION OF THE INVENTION
The Bleaching Composition
The compositions according to the present invention are preferably liquid compositions as opposed to a solid or a gas. As used herein “liquid” includes “pasty” compositions. The liquid compositions herein are aqueous compositions, comprising water at a level of preferably 10 to 99%, more preferably from 50% to 98% by weight of the bleaching composition. The liquid compositions according to the present invention have a pH below 7. Preferably, the pH of the compositions according to the present invention is from 0.1 to 6.5, more preferably from 0.5 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 instable 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.
The bleaching performance of the present composition may be evaluated by the following test methods on various type of bleachable stains.
A suitable test method for evaluating the bleaching performance on a soiled fabric under diluted conditions is the following: A composition according to the present invention is diluted with water typically at a dilution level of 1 to 100 ml/L, preferably 20 ml/L (composition water), then the soiled fabrics are soaked in it for 20 minutes to 6 hours and then rinsed. Alternatively the bleaching composition can be used in a washing machine at a dilution level of typically at a dilution level of 1 to 100 ml/L (composition water). In the washing machine the soiled fabrics are washed at a temperature of from 30° to 70° C. for 10 to 100 minutes and then rinsed. The reference composition in this comparative test undergoes the same treatment. Soiled fabrics/swatches with for example tea, coffee and the like may be commercially available from E.M.C. Co. Inc.
The bleaching performance is then evaluated by comparing side by side the soiled fabrics treated with a composition of the present invention with those treated with the reference, e.g., the same composition but comprising no bleach or a different bleach. A visual grading may be used to assign difference in panel units (psu) in a range from 0 to 4.
An advantage of the compositions of the present invention is that they are physically and chemically stable upon prolonged periods of storage.
Chemical stability of the compositions herein may be evaluated by measuring the concentration of available oxygen at given storage time after having manufactured the compositions. By “chemically sta
Di Capua Gloria
Dresco Pierre Antoine
Scialla Stefano
Delcotto Gregory
Echler Sr. Richard S.
Zerby Kim W.
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