DETERGENT COMPOSITION
This invention relates to a laundry detergent composition which is suitable for laundering fine fabric materials such as wool, silk, nylon, polyester and the like under relatively mild washing conditions.
Laundry detergent compositions generally employ anionic surfactants as the primary detergent-active compounds, such as alkyl benzene sulphonates, fatty alcohol sulphates or alkyl glycol ether sulphates. However, it has been found that a number of anionic surfactants damage the fibre structure of sensitive fabrics upon repeated washing. Fine fabric wash foririulations tend to contain a blend of anionic surfactants with non-ionic or amphoteric surfactants. The non-ionic surfactants are intended to increase detergency. However, when sensitive woollen fabrics are washed with non-ionics, the fabrics tend to feel comparatively hard and brittle. These effects can be intensified with machine washing. An addition of softening amphoteric surfactants does not completely counteract the loss of feel and, although amphoteric surfactants act as fibre-softening agents, some anionic and non-ionic surfactants reduce the softening effect of the amphoteric surfactants. Also, most known softening agents which are incorporated into detergents are detrimental to cleaning performance .
There is therefore a need for a fine fibre wash formulation which can be used to ash delicate fabrics such as woven or knitted wool_en fabrics and silk, which gives a good cleaning performance without having a detrimental effect o^ the properties of the fabric, and whicn ensures that the treated fabric has a soft feel .
In accordance with the present _nve-tion, there is provided a laundry detergent composition for washing delicate fabrics comprising:
one or more anionic, non-iome or amphoteric surfactants or a mixture of two or more thereof; b) a natural and/or synthetic ceramide; c a silicone; and optionally other detergent _ngredιents
Preferably, the detergent compos_tιcn comprises :
a) 2 to 60 wt % of one or more an_onιc, non-ionic or amphoteric surfactants or a mixture thereof;
b) from 0.001 to 5 wt % of one or more ceramides;
c) from 0.05 to 5 wt % of a pc_yd_ ethyl- siloxane; and
d) optionally other detergent _ngredιents to 100 wt %.
_> -
It has been found that the use in the present composition of a silicone and a ceramide lr combination provides a detergent with, simultaneously, a softening effect and an o.erall efficient cleaning performance.
Preferably, the silicone is a silicone f_^ιd, more preferably a silicone emulsion, and most preferably a silicone micro-emulsion Examp_.es of suitable silicones are polyalkyl or polyary_ silicones. Particularly preferred silicones are polydimethylsiloxanes , with organic groups incorporated into the basic silicone backbone, having the following structure:
wherein R is an amino, polyether, epoxy, hydroxyl, polyether/ammo, polyether/epoxy or cyclohexyl functional group; A may be any σroup suitable for ending the silicone chains, for example a hydrogen, methyl or hydroxyl grouo; and a and b are integers, preferably between 7 and 5000.
Examples of suitable silicones are those marketed under the trade names DC 225 (proαuced
by Dow Corning Corporation) and Magnasoft EM 410 oroduced by itco) .
The concentration of silicone in the compositions of the invention suitably lies in tne range from 0.05 to 5 wt %, preferably 0.1 to
2 wt % and most preferably the silicone concentration is about 0.5 wt %.
The ceramide present m the composition of the present invention may be a natural ceramide or a synthetic ceramide, for example an -acylsphmgenme or a derivative thereof. The amide-linked fatty acids are generally characterised by a C16 to C26, C„0/w-OH or C32/w-OH cnain. The long chain amine may be sphmgosme or sphmganme or phytosphingosine .
Particularly preferred ceramides are Bis (N-hydroxyethyl cetyl) Malanomide which is marketed under the trade name Questamide H and produced by Quest (this is synthetic "ceramide 2", with ceramide 2 being naturally found m hair) ; Palmitado-seπnate de myristyl which is marketed under the trade name ceramide A2 and produced by Sederma; Palmitadohexadecanediol which is marketed under the trade name Ceramide ιι and produced by Quest and a glycosphmgolipid marketed under the trade name ceramide PG5 and produced by Seporga.
The composition of the present invention may contain only one ceramide, or, alternatively, two or more different ceramides may be present.
The concentration of ceramiαe m the compositions of the invention suitably lies in the range from 0.001 to 5 wt %, preferably 0.001 to 2 wt % and most preferably 0.01 to 1 wt %.
The desired effects of the present invention are attained by the combined actions of the silicone emulsion and the ceramide in such a detergent formulation.
The composition of the present invention further includes detergent-active compounds. Many suitable detergent-active compounds are available and are fully described in the literature. The total amount of surfactant present in the composition of the present invention ranges from 2 to 60 ,vt _ by weight of the total fine fabric detergent composition, preferably 5 to 40 wt %, and most preferably 10 to 20 wt %.
The choice of anionic surfactant is not limited and any anionic surfactant suitable for use m a laundry composition may be used. Examples of suitable anionic surfactants are alky_benzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C8 -
C15; primary and secondary alkyl sulphates, particularly C8 - C15 primary alkyl sulphates; alkyl ether sulphates; olefm sulphonates; alkyl xylene sulphonates; dialkyi sulphosuccinates and fatty acid ester
sulphonates. Sodium salts are generally preferred .
Particularly preferred anionic surfactants are sodium lauryl ether sulphate, which is available under the trade name EMPICOL ESC3 from Albright &
Wilson; sodium lauryl sulphate, which is available under the trade name EMPICOL LX from
Albright & Wilson; α-olefine sulphonate, which is available under the trade name RHODACAL A 246 L from Rhόne-Poulenc and disodium lauryl sulphonsuccinate, which is available under the trade name REWOPOL 5B F12 from Witco.
The anionic surfactants are desirably present in amounts of 2 to 30 wt %, preferably 5 to 20 wt %, and most suitably the anionic surfactant concentration is about 10 wt %.
The choice of non-ionic surfactant is also not limited and any non-ionic surfactant suitable for use in a laundry composition may be used.
Examples of suitable non-ionic surfactants are primary and secondary alcohol ethoxylates, especially the C8 - C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and most particularly the C10 - C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated non-ionic surfactants include alkyl polyglycosides, glycerol
monoethers, alkanol amides and olyhdroxyamides (glucamide) .
Particularly preferrec. non-ionic surfactants are Coceth-6 (PEG ether of coconut alcohol);
Coceth-10 ( PEG ether of coconut alcohol);
Laureth-6 (PEG ether of lauryl alcohol);
Lauramide DEA, which is availble under the trade name EMPILAN 26224 from Albright & Wilson; and lauryl polyglucoside, which is available under the trade name PLANTERE 12.0CΞ/UP from Henkel .
The non-ionic surfactants are desirably presen; in amount of 0 to 20 wt ., preferably 0.5 to 10 wt %, and most suitably about 1 to 2 wt % .
Particularly preferrec. amphoteric surfactants are cocoamidopropylbetaine, such as that available under the trace name ΞMPIGEN from Albright & Wilson and arr.ine oxides, such as lauramine oxide, which is available under the trade name TEGAMINE OXIDE W from Goldsch.
The amphoteric surfactants are desirably present in amounts of 0.5 t: 2C wt % and preferably 0.5 to 10 wt ..
In addition to the above specified ingredients and water, the compositions of the present invention can optionally contain relatively minor amounts of the usual types of non-surfactant auxiliary ingredients as are commonly employed in conventional laundry detergents, for example inorganic salts such as sodium carbonate, sodium
sulphate or sodium silicate (where the composition is a powder) ; anti-redeposition agents such as cellulosic polymers; preservatives; optical brighteners; pearlescmg agents; colourants; viscosifymg agents such as sodium chloride and pH regulators such as citric acid. This list is not intended to be exhaustive .
Detergent compositions of the invention may be of any suitable form, for example powders or granules, liquids or gels. The manner in which the detergent compositions are prepared or formulated is not particularly critical and such may be prepared by methods well known to those skilled in the art.
The detergent compositions of the present invention are especially well suited and beneficial for the laundering under relatively mild washing conditions (e.g. mild or gentle machine agitation or hand washing and at low or cold wash water temperature) of fine fabric materials such as knitted fabrics of wool and silk, nylon and polyester. In addition to an excellent washing result, these fabrics do not become hard, but instead retain their natural softness, not only with hand washing but also with machine washing.
In order that the invention may be more fully understood, it will now be described with reference to the following examples, m which all percentages are on a weight basis .
Exa pl e 1
A fine fabric wash detergent composition was prepared from the following ingredients:
A fine fabric wash detergent composition was prepared from the following ingredients:
Example 3
A fine fabric wash detergent composition was prepared from the following ingredients:
Example 4
A fine fabric wash detergent composition was prepared from the following ingredients:
Example 5
A fine fabric wash detergent composition was prepared from the following ingredients:
In order to demonstrate the desired effects of the present invention, the following test was performed.
Wool fibres of diameter 0.1 - 0.14 mm were evaluated for elasticity using a Rheometrics RSA 2 Solids analyser fitted with a monofilament geometry to give a sample length of 24 mm. The test used was a steady strain rate test using a constant strain rate of 0.0001 s"1 with the temperature controlled at 20°C. This allowed measurement of Youngs modulus for a strain
between 2 and 3 % in the elastic region of the wool fibre which is equal to the elastic modules G1 . Values of G1 are given in the table below :
Elasticity . Wool without treatment 9. 66 x 107 Pa/%
Wool washed 3 times with water only 3. 23 x 107 Pa/%
Wool washed 3 times with detergent formulation containing a ceramide 3. 73 x 107 Pa/%
Wool washed 3 times with detergent formulation containing a ceramide plus a 6. 79 x 107 Pa/% silicone emulsion
From the results it can be seen that a formulation containing a ceramide and a silicone emul sion significantly increased the elasticity of the wool fibre compared to washing in water alone or with a formulation containing ceramide alone .
Furthermore, further tests carried out on different fabrics showed a noticeable improvement of the softness of each fabric when the fabric was washed in a detergent formulation containing ceramide and silicone emulsion compared to washing in water alone or in a standard detergent formulation which did not contain a silicone derivative or a ceramide. Derived from cosmetics technology, it would appear that the ceramides penetrate into the fibres to restore both their strength and volume. In addition, the silicone appears to impart a softness to all types of textiles .
For example, the following test was performed to demonstrate the improved softness of fabrics washed in a detergent formulation in accordance with the present invention.
Four groups of wool or wool/acrylic fabrics were hand-washed in:
Formulation 1 : the formulation in accordance with Example 3, as described previously;
Formulation 2 : the formulation of Example 3 minus any ceramide or silicone emulsion;
Formulation 3: the formulation in accordance with Example 5, as described previously; and
Formulation 4 : the formulation of Example 5 minus any ceramide or silicone emulsion.
The fabrics were hand-washed with 35 ml of the detergent diluted in 5 litres of water (middle hardness water) at 30°C and then rinsed twice in 5 litres of cold water.
After 3 washes, panellists were asked to compare the softness of the washed fabrics. The figures given in the table below indicate the preceived softness of the fabrics as compared to the softness of the fabrics prior to washing.