Field of the invention
[0001] The present invention relates to a detergent composition for effective stain removal.
The invention has been developed primarily for use in detergent compositions and will
be described hereinafter with reference to this application. However, it will be appreciated
that the invention is not limited to this particular field of use.
Background of the invention
[0002] Any discussion of the prior art throughout the specification should in no way be
considered as an admission that such prior art is widely known or forms part of the
common general knowledge in the field.
[0003] Washing of used fabrics with a detergent composition to remove dirt and stains is
common practice. Surfactants present in the detergent composition act on dirt and
stain and suspend them in the wash liquor. The suspended particles are subsequently
removed at the time of rinsing. Surfactants are prone to precipitate by reacting with
some ions namely Ca
2+ and Mg
2+ which are often present in wash liquor. The precipitation of the surfactants reduces
the cleaning efficiency.
[0004] Builders are added to the detergent composition primarily to complex with Ca
+2 and Mg
2+ and thereby reduce hardness of water. In addition to removing Ca
2+ and Mg
2+ ions, some builders also emulsify soil particles, reduce soil re-deposition by suspending
the soil in the wash liquor and provide alkalinity which assists in dissolving oil-based
soils. Use of an ineffective builder or the use of an ineffective amount of a builder
lessens the cleaning performance of surfactants.
[0005] Builders are classified as sequestering, precipitating or ion exchange builders.
Sodium tripolyphosphate is a phosphate type sequestering builder which, in addition
to removing the dissolved ions, helps disperse and suspend soil in the wash liquor
and emulsifies oily material. For this reason phosphates such as tripolyphosphates
and pyrophosphates have been widely used as builders. The effect of phosphates upon
the eutrophication of lakes and streams has been questioned and their use in detergent
compositions has been subject to government scrutiny and regulation.
[0006] Alternatives for phosphate builders have been known. However such alternatives have
one or the other drawbacks.
[0007] Zeolites, used as alternative builders are ion-exchange builders which provide benefits
comparable to phosphate builders but are not desirable as they are water insoluble
and can foul sewer lines and water treatment facilities.
[0008] Precipitating builders, for example sodium carbonate, are environment friendly and
removes Ca
2+ and Mg
2+ ions as precipitated calcium and magnesium particles. Use of precipitating builders
may reduce the cleaning activity by deposition of precipitated calcium and magnesium
particles on the fabric. Further, as compared to the phosphate builders, precipitating
builders have slow Ca
2+ and Mg
2+ ions removal efficiency and are ineffective at completely preventing precipitation
of surfactants owing to their reaction with calcium and magnesium ions. This further
reduces the cleaning efficiency of detergent composition having precipitating builders.
[0009] Bleaches are yet another widely used ingredient in the detergent composition that
removes stain. Peroxygen bleach compounds can bleach stains without damaging the colour
of the fabrics and hence are widely used. To bleach stains at temperature below 60°C
requires bleach activators in combination with peroxygen bleach compounds. Under the
action of a bleach, stains are oxidized and broken into fragments which are later
suspended in the solution by the surfactant. A lowered efficiency of surfactant in
presence of precipitating builder may also affect the bleach efficiency. Presence
of clay or soil on the fabric further reduces bleaching of hydrophobic stains.
[0010] Hence it is difficult to achieve effective dirt and stain removal with a detergent
composition having precipitating builder but which does not cause eutrophication of
lakes and streams and which is environment friendly. It is therefore desired to provide
a detergent composition with a precipitating builder for effective removal of bleachable
stains. It is further desired to provide a detergent composition having a non-phosphate
precipitating builder that effectively removes tough hydrophobic stains.
[0011] Detergent compositions having peroxygen bleach compound and hydrophobic bleach activator
are known in the art.
[0012] US5043089 (1991, Akzo N.V) discloses a novel p-sulphophenyl alkyl carbonates where the alkyl
group contains 6 to 10 carbon atoms providing an effective bleach activator. This
application also discloses a detergent composition having the bleach activator, a
bleaching agent and a surfactant. This application does not disclose a detergent composition
having non-phosphate builders for providing effective stain removal.
[0013] GB2395488A (2004, Reckitt Benckiser N. V.) discloses a process of removing coloured stains from
hydrophobic surfaces by treating with a formulation having a salt of sulphophenyl
alkyl carbonate. The formulation may additionally include an oxygen source, a builder,
a surfactant and preferably encapsulated enzyme. This application discloses detergent
compositions having phosphate builders.
[0014] It is an object of the present invention to provide a detergent composition having
a non-phosphate precipitating builder which effectively removes hydrophobic stains.
It is yet another object of the present invention to provide a detergent composition
which can be used at lower wash temperatures.
[0015] It is yet another object of the present invention to provide a detergent composition
which is environment friendly.
[0016] It has been determined by the present inventors that a detergent composition having
a combination of specific bleach activator, a non-phosphate precipitating builder
and an enzyme provides for effective removal of stains particularly the tough hydrophobic
stains.
Summary of the invention
[0017] According to the first aspect, the present invention provides a detergent composition
comprising:
- (i) a precipitating builder;
- (ii) 0 to 5 wt% of zeolites or a phosphate sequestering builder or mixtures thereof;
- (iii) 2 to 80 wt% surfactant;
wherein the composition comprises:
- (i) an enzyme; and,
- (ii) a bleach activator of the general formula (I)
and where R is an alkyl group with 6 to 10 carbon atoms and M+ is a cation, characterized
in that the enzyme is a mixture of lipase, mannanase, amylase and protease enzymes.
[0018] According to the second aspect, the present invention provides for a method of bleaching
a bleachable substrate comprising the steps of:
- (i) applying to the substrate a neat or diluted form of the composition of the first
aspect;
- (ii) rinsing the substrate.
[0019] According to the third aspect disclosed is a use of the detergent composition of
the first aspect for bleaching tough hydrophobic stains.
[0020] The invention will now be explained in more details.
Detailed description of the invention
[0021] In accordance with a first aspect, the invention provides a detergent composition
having a precipitating builder, a surfactant, a bleach activator and an enzyme.
Precipitating builder
[0022] Builders used in the detergent composition may be classified in various ways. One
method of classification of detergent builders is based on their mode of action and
includes classification into sequestering, precipitating and ion-exchange builders.
Another conventional method of classification of detergent builders is to classify
them as inorganic and organic detergent builders. Yet another method of classification
is based on their solubility in water and is accordingly classified as water soluble
or water insoluble builders.
[0023] Disclosed detergent composition includes a precipitating builder. In contact with
the ions Ca
2+ and Mg
2+ generally present in the wash liquor precipitating builders precipitate out as a
complex with the water hardness cations (Ca
2+ and Mg
2+), thereby performing a builder function. Specific examples of precipitating builders
include sodium fatty acid sulphonate, long chain fatty acid soaps, water-soluble salts
of carbonates, bicarbonates, sesquicarbonates, silicates, aluminates and oxalates.
Alkali metal salts, especially sodium salts of the foregoing materials are preferred
for convenience and economy. Preferably the precipitating builder is a water-soluble
carbonate salt. It is highly preferred that the precipitating builder is sodium carbonate.
It is highly preferred that the precipitating builder of the present invention is
a non-phosphate precipitating builder. Preferably the precipitating builder is present
from 5 wt% to 80 wt% in the composition, more preferably from 10 wt% to 60 wt%, still
more preferably from 12 wt% to 30 wt% and most preferably from 15 wt% to 25 wt%.
[0024] A crystallization seed may be used in the detergent composition along with the precipitating
builder; such crystallization seed quickens the rate of precipitation of the metal
cations, and thereby removes the hardness before it can adversely affect detergency
performance.
Zeolites and Sequestering builders
[0025] Disclosed detergent composition includes 0 to 5 wt% of a zeolites or a phosphate
sequestering builder or mixtures thereof.
Zeolites:
[0026] Disclosed detergent composition includes 0 to 5 wt% of zeolites. It is preferred
that the detergent composition of the present invention not more than 4wt%, further
preferably not more than 2wt% of zeolites and highly preferred composition is free
of the zeolite builders.
[0027] Zeolites are ion-exchange builders and are substantially water insoluble builders
which are capable of reducing the hardness content of laundering liquors. Ion-exchange
builder may be crystalline or amorphous aluminosilicates. Aluminosilicates can be
naturally occurring aluminosilicates or synthetically derived. Preferred synthetic
crystalline aluminosilicate ion-exchange materials useful herein are available under
the designations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and mixtures thereof.
In an especially preferred embodiment, the crystalline aluminosilicate ion-exchange
material is Zeolite A.
[0028] Another preferred aluminosilicate zeolite is zeolite MAP builder. Zeolite MAP is
described in
EP 384070A (Unilever). It is defined as an alkali metal alumina-silicate of the zeolite P type
having a silicon to aluminium ratio not greater than 1.33, preferably not greater
than 1.15 and, more particularly, not greater than 1.07 and preferably within the
range of from 0.9 to 1.2.
Sequestering builder:
[0029] Disclosed detergent composition includes 0 to 5 wt% of a phosphate sequestering builder.
It is preferred that the detergent composition of the present invention includes not
more than 4wt%, further preferably not more than 2wt% of the phosphate sequestering
builders and highly preferred composition is free of the phosphate sequestering builders.
[0030] Sequestering builders are water soluble builder that forms water soluble complexes
with Ca
2+ and Mg
2+ ions. Phosphate sequestering builders include orthophosphates, tripolyphosphate,
alkali metal pyrophosphates and organic phosphonates. Examples of the phosphate sequestering
builders include sodium tripolyphosphate, tetrasodium pyrophosphate, hexametaphosphate,
and tetrapotassium pyrophosphate. Examples of organic phosphonates includes the sodium
and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts
of ethane 1-hydroxy-1,1 diphosphonic acid, and the sodium and potassium salts of ethane-1,1,2-triphosphonic
acid.
[0031] Examples of non-phosphate sequestering builders that may be present in the detergent
composition of the present invention for use as builders includes hydrocarboxylates
(citrates, tartrates, succinates, gluconates), polycarboxylates, aminocarboxylates
(ethylenediaminetetraacetate(EDTA), and nitrilotriacetate (NTA)) diethylene triamine
pentaacetic acid (DTPA), hydroxyethylene diamine triacetic acid (HEDTA), dihydroxyethyl
glycine (DEG), and triethanolamine.
Surfactant
[0032] Disclosed detergent composition includes 2 to 80 wt% surfactant. It is preferred
that the detergent composition includes atleast 10 wt% surfactant more preferably
at least 20wt% and still more preferably atleast 30wt% of the surfactant. It is preferred
that the disclosed detergent composition includes not more than 70wt%, preferably
not more than 60wt% and more preferably not more than 50wt% and still preferably not
more than 40wt% of the surfactant.
[0033] Disclosed cleaning composition preferably includes a surfactant. The surfactant may
be a soap or an anionic, nonionic, amphoteric, zwitterionic or cationic surfactant
or mixtures thereof. In general, the nonionic and anionic surfactant may be chosen
from the surfactants described in "
Surface Active Agents" Vol. 1, by Schwartz and Perry, Interscience 1949,
Vol. 2 by Schwartz, Perry and Berch, Interscience 1958, in the current edition of "McCutcheon ' s Emulsifiers and Detergents" published
by Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H.Stache, 2nd
Edn., Carl Hauser Verlag, 1981.
[0034] Suitable anionic surfactant includes water-soluble alkali metal salts of organic
sulphates and sulphonates having alkyl radicals containing from about 8 to about 22
carbon atoms, the term alkyl includes the alkyl portion of higher acyl radicals. Examples
of suitable synthetic anionic surfactant are sodium and potassium alkyl sulphates.
Especially preferred are the sodium and potassium sulphates obtainable by sulphating
higher C
8 to C
18 alcohols for example from tallow or coconut oil. Other preferred anionic surfactant
include sodium and potassium alkyl C
9 to C
20 benzene sulphonates, particularly sodium linear secondary alkyl C
10 to C
15 benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those
ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols
derived from petroleum.
[0035] Most preferred anionic surfactants are sodium lauryl ether sulfate (SLES), particularly
preferred are anionic surfactant with 1 to 3 ethoxy groups, sodium C
10 to C
15 alkyl benzene sulphonates (LAS) and sodium C
12 to C
18 alkyl sulphates (PAS). Alkyl ester suphonates such as methyl ester sulphonates (MES)
may be preferably used for replacing a portion or completely replacing the anionic
surfactant.
[0036] Other suitable surfactants are those described in
EP-A-328 177 (Unilever), which shows resistance to salting-out, the alkyl polyglycoside surfactants
described in
EP-A-070 074 and alkyl monoglycosides. The surfactant chain may be branched or linear. Suitable
nonionic surfactants include the reaction products of compounds having a hydrophobic
group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides
or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with
propylene oxide. Preferred nonionic surfactants are C
6 to C
22 alkyl phenol-ethylene oxide condensates, generally having 5 to 25 EO, i.e. 5 to 25
units of ethylene oxide per molecule, and the condensation products of aliphatic C
8 to C
18 primary or secondary linear or branched alcohols with ethylene oxide, generally 5
to 50 EO. Preferably, the non-ionic is 10 to 50 EO, more preferably 20 to 35 EO. Alkyl
ethoxylates are particularly preferred.
[0037] Soaps may also be present. The fatty acid soap used preferably contains from about
16 to about 22 carbon atoms, preferably in a straight chain configuration. Preferred
soap may be derived from saturated and non-saturated fatty acids obtained from natural
sources and synthetically prepared. Examples of such fatty acids include capric, lauric,
myristic, palmitic, stearic, oleic, linoleic and linolenic acid. The anionic contribution
from soap is preferably from 0 to 30 wt% of the total anionic.
[0038] Preferred surfactant systems are mixtures of anionic with nonionic surfactant, in
particular the groups and examples of anionic and nonionic surfactants pointed out
in
EP-A-346 995 (Unilever).
[0039] Amounts of amphoteric or zwitterionic surfactants can also be used in the compositions
of the invention but this is not normally desired owing to their relatively high cost.
If any amphoteric or zwitterionic surfactants are used, it is generally in small amounts
in combinations with anionic and nonionic surfactants.
Enzyme
[0040] Disclosed detergent composition includes a mixture of protease, lipase, amylase and
mannanase enzymes.
Protease:
[0041] Disclosed detergent composition includes a protease. Suitable protease includes those
of animal, vegetable or microbial origin. Protease from microbial origin is preferred.
Protease may also be chemically modified or protein engineered mutant. Preferably
the protease is a serine protease or a metallo protease, preferably an alkaline microbial
protease or a trypsin-like protease. Examples of alkaline proteases are subtilisins,
especially those derived from Bacillus, examples include subtilisin Novo, subtilisin
Carlsberg, subtilisin 309, subtilisin147 and subtilisin 168 (described
WO8906279A1) Examples of trypsin-like proteases are trypsin from porcine or bovine origin and
the Fusarium protease described in
WO8906270A1 and
WO9425583A1. The protease, is preferably from B.subtilis. Preferred commercially available protease
includes Alcalase™, Savinase™, Primase™, Duralase™, Dyrazym™, Esperase™, Everlase™,
Polarzyme™, and Kannase™, Maxatase™, Maxacal™, Maxapem™, Properase™, Purfast®, Effectenz®,
Purafect™, Purafect OxP™, FN2™, and FN3™ (Genencor International Inc.).
[0042] Protease from a strain of Bacillus having maximum activity throughout the pH range
of 8 to 12 is highly preferred and includes commercially available Esperase™ and Savinase™.
[0043] Preferably the detergent composition of the present invention include 0.001 wt% to
10 wt% more preferably from 0.01 wt% to wt% of protease depending upon their activity.
Lipase:
[0044] Disclosed detergent composition includes a lipase. Lipase catalyses hydrolysis of
ester bonds of edible fats and oils, i.e. triglycerides, into free fatty acids, mono-
and diglycerides and glycerol.
[0045] Preferred lipases include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Examples of useful lipases include lipases
from Humicola species (incl. Thermomyces. species) which includes lipase from H. lanuginosus
(T. lanuginosus) as described in
EP0258068B1 and
EP0305216B1 or from H. insolens as described in
WO9613580A1 or lipases from Pseudomonas species which includes lipase from P. alcaligenes or
P. pseudoalcaligenes (
EP0218272 A1), P. cepacia (
EP0331376B1), P. stutzeri (
GB 1 ,372,034), P. fluorescens, Pseudomonas species strain SD 705 (
WO95/06720 and
WO96/27002), P. wisconsinensis (
WO96/12012) or lipases from Bacillus species which includes lipases from B. subtilis (
Dartois et al. (1993), Biochemica et Biophysica Acta, 1131, 253-360), B. stearothermophilus (
JP64/744992) or B. pumilus (
WO 91/16422). Other examples include lipase variants such as those described in
WO92/05249,
WO94/01541,
EP407225,
EP260105,
WO96/35381,
WO96/00292,
WO95/30744,
WO94/25578,
WO95/14783,
WO95/22695,
WO97/04079 and
WO97/07202.
[0046] Preferred commercially available lipases are available under the trademarks Lipoclean®,
Lipolase®, Lipolase® Ultra and Lipex®. LIPEX® is particularly preferred, and LIPEX®
100 T is further particularly preferred. The activity of commercial lipase is commonly
expressed as Lipase Units or LU. Different lipase preparations may have different
activities. For fungal lipases these may range from 2,000 to 2,000,000 LU per gram.
Preferred compositions include lipase having 5 to 20000LU/g.
[0047] In order to prevent accidents and to alleviate safety concerns, commercial lipases
are always coated with an inert material. Therefore, commercial lipases that are used
for detergent powders, bars and tablets are in granular form containing very low amount
of active lipase and balance of adjunct materials. Such granulates contain lipase
concentrate, inorganic salt, binders and coating materials. They are free-flowing
so that there is no lumping, and the granulate dissolve faster. Lipases are also available
in liquid form, example LIPEX ® 100 L.
[0048] Preferred detergent composition has 0.0001wt% to 0.3wt% lipase, more preferably from
0.0001 to 0.1wt% lipase and further preferably 0.0009wt% to 0.00186 wt% lipase.
Amylase:
[0049] Disclosed detergent composition includes an amylase. Suitable amylases (alpha-amylase
and/or beta-amylase) include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Examples of amylase suitable for the present
invention includes alpha-amylase obtained from Bacillus species which includes special
strain of B. licheniformis, described in more detail in
GB 1,296,839, or the Bacillus species strains disclosed in
WO 95/026397 or
WO 00/060060. Other suitable examples of amylases are the variants described in
WO 94/02597,
WO 94/18314,
WO 96/23873,
WO 97/43424,
WO 01/066712,
WO 02/010355 and
WO 02/031124 (which references all incorporated by reference).
[0050] Commercially available amylases are Duramyl(TM), Termamyl(TM), Termamyl Ultra(TM),
Natalase(TM), Stainzyme(TM), Stainzyme Plus(TM), Fungamyl(TM) and BAN(TM) (Novozymes
A/S), Rapidase(TM) and Purastar(TM) (from Genencor International Inc.).
Mannanase:
[0051] Disclosed composition includes mannanase. Examples of suitable mannanase include
those of bacterial or fungal origin. Preferably the mannanase is derived from a strain
of a filamentous fungus genus Aspergillus, preferably Aspergillus niger or Aspergillus
aculeatus (
WO 94/25576).
WO 93/24622 disclosing a mannanase isolated from Trichoderma reese is also preferred. Mannanases
have also been isolated from several bacteria, including Bacillus species. For example,
Talbot et al.,Appl. Environ. Microbiol., Vol.56, No. 11, pp. 3505-3510 (1990) describes a beta-mannanase derived from Bacillus stearothermophilus.
Mendoza et al., World J. Microbiol. Biotech., Vol. 10, No. 5, pp. 551 -555 (1994) describes a beta-mannanase derived from Bacillus subtilis.
JP-A-03047076 discloses a beta-mannanase derived from Bacillus sp.
JP-A-63056289 describes the production of an alkaline, thermostable beta- mannanase.
JP-A-63036775 relates to the Bacillus microorganism FERM P-8856 which produces beta-mannanase and
beta-mannosidase.
JP-A-08051975 discloses alkaline beta-mannanases from alkalophilic Bacillus sp. AM-001. A purified
mannanase from Bacillus amyloliquefaciens is disclosed in
WO 97/11164.
[0052] Examples of preferred commercially available mannanases include Mannaway(TM) available
from Novozymes A/S Denmark.
Bleach activator
[0053] Disclosed detergent composition includes a bleach activator of the general formula
and where R is an alkyl group with 6 to 10 carbon atoms and M
+ is a cation. Preferably the alkyl group R is selected from n-hexyl, n-octyl or 2-ethylhexyl.
[0054] Preferably the cation M
+ is sodium or potassium. It is highly preferred that the bleach activator is sodium
4-sulphophenyl 2-ethylhexyl carbonate.
[0055] The bleach activator may be in the form of a powder or as particulate bodies having
the bleach activator, a binder or agglomerating agent. It is preferred for reasons
of stability and handling that the bleach activator is in the form of particulate
bodies.
Peroxygen bleach compound:
[0056] Disclosed composition preferably includes a peroxygen bleach compound capable of
yielding hydrogen peroxide in aqueous solution. Hydrogen peroxide sources are well
known in the art. Hydrogen peroxide sources are described in details in
Kirk Othmer's Encyclopedia of Chemical Technology, 4th Ed (1992, John Wiley & Sons),
Vol. 4, pp. 271-300 "Bleaching Agents (Survey)", and include the alkali metal salts of sodium perborates
and sodium percarbonates, including various coated and modified forms. Suitable peroxygen
bleach compounds include hydrogen peroxide or any of its solid adducts such as organic
peroxides example; urea peroxide and inorganic persalts such as the alkali metal perborates,
percarbonates, perphosphates, persilicates and persulphates. Mixtures of two or more
such compounds may also be suitable.
[0057] Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and
sodium percarbonate. Percarbonate is stable during storage and dissolves quickly in
the cleaning liquor and is especially preferred. It is believed that such rapid dissolution
results in the formation of higher levels of percarboxylic acid and, thus, enhances
substrate bleaching performance. Highly preferred percarbonate is in uncoated or coated
form. Preferably the average particle size of uncoated and coated percarbonate ranges
from about 400 to about 1200 µm, most preferably from about 400 to about 600 µm. If
coated percarbonate is used, the preferred coating materials include mixtures of carbonate
and sulphate, zeolite, precipitated silica, waxes, borates, polymers, citrates, silicate,
borosilicate or fatty acids.
[0058] Preferably the disclosed detergent composition has 4 to 35 wt% of the peroxygen bleach
compound more preferably 5 to 20 wt % and further preferably 10 to 15 wt% of the peroxygen
bleach compound.
Form of detergent composition:
[0059] Preferably the disclosed detergent composition is a granular detergent composition.
Preferably the granular detergent composition is of a low to moderate bulk density.
Preferred granular detergent composition may be made of any known methods for manufacturing
a granular detergent composition that includes spray-drying, drum drying, fluid bed
drying, and scraped film drying preferably using the wiped film evaporator.
[0060] Alternatively, the granular detergent composition may be in a 'concentrated' or 'compact'
form. Such detergent composition may be prepared by mixing and granulating process,
for example, using a high-speed mixer or granulator, or other non-tower process.
[0061] Preferably the pH of the aqueous solution on dissolution of the detergent composition
is 6 to 12 and more preferably from 7 to 10.5.
Optional ingredients:
[0062] Disclosed detergent composition may include one or more of other ingredients selected
from bleach stabilizer, polymers, perfumes, fluorescers, soil release polymers, germicides,
colourants and coloured speckles. This list is not intended to be exhaustive.
[0063] Disclosed composition may include a bleach stabiliser. Suitable bleach stabilisers
include ethylenediamine tetraacetate (EDTA), ethylenediamine disuccinate (EDDS), and
the aminopolyphosphonates such as ethylenediamine tetramethylene phosphonate (EDTMP)
and diethylenetriamine pentamethylene phosphonate (DETPMP).
[0064] When present the composition may include one or more polymers. Examples include carboxymethylcellulose,
poly (ethylene glycol), poly (vinyl alcohol), polycarboxylates such as polyacrylates,
maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers. Suitable
commercially available polymer includes Sokalan CP5 (ex BASF) which is a polyacrylate,
namely maleic acid-acrylic acid copolymer, with a sodium salt.
[0065] Disclosed detergent composition may also include perfumes. When present the perfumes
could be of natural origin or synthetic. They include single compounds or mixtures
of compounds. By perfume in this context is not only meant a fully formulated product
delivering fragrance, but includes selected components of that fragrance, particularly
those which are prone to loss, such as the so-called top notes. Preferably perfume
may be used in the form of neat oil or in an encapsulated form.
[0066] Disclosed composition may also include fluorescent agent (optical brightener).
[0067] Fluorescent agents are well known and many such fluorescent agents are available
commercially. Usually, these fluorescent agents are supplied and used in the form
of their alkali metal salts, for example, the sodium salts. The total amount of the
fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt%,
more preferably 0.01 to 0.1 wt%. Preferred fluorescent agent includes but not limited
to di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, diamine stilbene
disulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark)
HRH and pyrazoline compounds, e.g. Blankophor SN. Preferred fluorescers are: sodium
2- (4-styryl-3-sulfophenyl) -2H-napthol [1,2-d]triazole, disodium 4, 4'-bis{[(4-anilino-6-
(N methyl-N-2 hydroxyethyl) amino 1,3,5-triazin-2-yl)]amino}stilbene-2-2' disulfonate
and disodium 4,4'- bis (2-sulfoslyryl) biphenyl. Tinopal® DMS is the disodium salt
of disodium 4,4'-bis{[(4-anilino-6-morpholino-1 ,3,5-triazin-2-yl)]amino} stilbene-2-2'
disulfonate. Tinopal® CBS is the disodium salt of disodium 4,4'-bis(2-sulfostyryl)biphenyl.
[0068] Disclosed composition may include a soil release polymer, for example sulphonated
and unsulphonated PET/PEOT polymers, both end-capped and non-end-capped, and polyethylene
glycol/polyvinyl alcohol graft copolymers such as Sokolan (Trade Mark) HP22. Especially
preferred soil release polymer are the sulphonated non-end-capped polyesters described
and claimed in
WO9532997A (Rhodia Chimie)
[0069] In accordance with a second aspect, disclosed invention provides a method of bleaching
a bleachable substrate comprising the steps of applying to the substrate a neat or
diluted form of the composition as according to the first aspect; and rinsing the
substrate.
[0070] In accordance with a third aspect, disclosed invention provides an use of a detergent
composition as claimed in any one of the preceding claims for effective removal of
tough hydrophobic stains.
[0071] The invention will now be explained in details with the help of non-limiting exemplary
embodiments.
Examples
Evaluation of the preferred and the comparative compositions in removal of tough hydrophobic
stains (lipstick stain and tomato ketchup stain):
a) Measurement of Soil Release Index (SRI)
[0072] Soil release index (SRI) is a measure of the amount of a stain present on fabric
that is removed during a washing process. The intensity of any stain after washing
is measured by means of a spectrophotometer and expressed in terms of the difference
between the stained fabric and a clean fabric giving ΔE* for each stain. It is defined
as ΔE* and is calculated as:
[0073] L*, a*, and b* are the coordinates of the CIE 1976 (L*, a*, b*) colour space, determined
using a standard spectrophotometer. ΔE* can be measured before and after the stain
is washed, to give ΔE*bw (before wash) and ΔE*aw (after wash).
[0074] ΔE after wash is the difference in L a b colour space between the clean (unwashed)
fabric and the stained fabric after wash. So a ΔE after wash of zero means that a
stain is completely removed.
[0075] SRI is defined as:
[0076] A SRI of 100 means complete removal of a stain. The higher the SRI value, the greater
is the stain removal potential.
[0077] The clean (or virgin) fabric is an "absolute standard". For each experiment, it refers
to an identical piece of fabric to that to which the stain is applied. Therefore,
its point in L a b colour space stays constant.
b) Preparation of the preferred and comparative detergent composition
[0078] A control detergent composition (Control) was formulated with sodium carbonate as
the precipitating builder and 2.6% zeolite 4A. The control composition had no bleach,
no bleach activator and no enzyme. Other standard laundry detergents were included.
The composition of Control is provided in Table 1.
[0079] A first comparative detergent composition (Comp A) was formulated by adding sodium
4-sulphophenyl 2-ethylhexyl carbonate (bleach activator according to the invention)
and sodium percarbonate (bleach) to the control composition. The first comparative
detergent composition had no enzyme.
[0080] A second comparative detergent composition (Comp B) was formulated by adding enzymes
protease, lipase, amylase and mannanase to the control composition. The second comparative
detergent composition had no sodium 4-sulphophenyl 2-ethylhexyl carbonate (bleach
activator) and sodium percarbonate (bleach).
[0081] A preferred detergent composition (Ex 1) was formulated by addition of sodium 4-sulphophenyl
2-ethylhexyl carbonate (bleach activator according to the present invention), sodium
percarbonate (bleach) and enzymes protease, lipase, amylase and mannanase to the control
composition.
[0082] The formulations of control, comparative compositions (Comp A, Comp B) and preferred
composition (Ex 1) is provided in Table 1.
c) Washing protocol for determining SRI-values
[0083] For the determination of the SRI-values, a standard protocol was used, called the
machine wash protocol.
[0084] Said machine wash protocol is as follows:
- (a) A set of 6 knitted cotton swatches and another set of 6 woven cotton swatches
were taken.
- (b) Each woven cotton swatch was stained with tomato ketchup stain and each of the
knitted cotton swatches were stained with lipstick stain.
- (c) Colour of the two stains on the cotton swatches were measured before washing to
get ΔE*bw (before wash).
- (d) 7gpl of the control composition was added to a Miele Washing machine Softronic
W4165.
- (e) A normal white wash cotton intensive cycle 1 hour 56 minutes was selected with
water temperature of 40°C. The total wash liquor used was 6 litres. The water used
had a hardness 24° French hardness. The wash load was 1.5 kg.
- (f) The wash load included the stained cotton swatches and two SBL soil strips and
the liquor to cloth ratio was 4:1. The stained cotton swatches were not soaked before
washing.
- (g) Post washing the cotton swatches was dried overnight.
- (h) The after wash reading of the stain on the 6 knitted cotton swatches and the 6
woven cotton swatches were recorded.
[0085] Similarly the stained cotton swatches were prepared and washed as described in the
above steps (a) to (h) with comparative compositions (Comp A, Comp B) and preferred
composition (Ex 1) and the reading of the swatches were taken before and after wash.
d) Measurement of the delta SRI values
[0086] The delta SRI value after wash was determined as the difference between the absolute
SRI value for a stained cotton swatch washed with the preferred or comparative composition
and absolute SRI value for a stained cotton swatch washed with the control composition.
[0087] For preferred composition (Ex 1):
[0088] For comparative composition: (Comp, Comp B)
[0089] A delta SRI value higher than the LSD (Least significant difference) value indicates
a statistically significant difference between the absolute SRI values of stained
swatch washed with the preferred composition or comparative composition and the absolute
SRI value of stained swatch washed with control composition.
[0090] The delta SRI values of the cotton swatches stained with lipstick stain and with
tomato ketchup stain after washing with control, comparative, preferred compositions
with the machine wash protocol described above are provided in Table 2.
Table1
Ingredients |
Control (wt%) |
Comp A (wt%) |
Comp B (wt%) |
Ex 1 (wt%) |
Na-LAS |
11.69 |
11.69 |
11.69 |
11.69 |
Non-Ionic 7EO |
1.17 |
1.17 |
1.17 |
1.17 |
Sodium Soap |
0.63 |
0.63 |
0.63 |
0.63 |
Na disilicate |
6.23 |
6.23 |
6.23 |
6.23 |
Soda Ash |
20.64 |
20.64 |
20.64 |
20.64 |
Sodium Sulphate |
49.28 |
34.58 |
34.13 |
34.129 |
SOKLAN CP5 (ex BASF, polymer of maleic acid and acrylic acid) |
0.39 |
0.39 |
0.39 |
0.39 |
SCMC(sodium carboxy methyl cellulose) |
0.23 |
0.23 |
0.23 |
0.23 |
Tinopal CBSx |
0.02 |
0.02 |
0.02 |
0.02 |
Zeolite 4A |
2.613 |
2.613 |
2.613 |
2.613 |
TAED |
0 |
0 |
2.7 |
0 |
sodium 4-sulphophenyl 2-ethylhexyl carbonate |
0 |
2.7 |
0 |
2.7 |
Sodium Percarbonate |
0 |
12.00 |
12.00 |
12.00 |
EDTMP Ca/Na salt (Dequest 2047) |
0.369 |
0.369 |
0.369 |
0.369 |
Citric Acid anhydrous |
1.90 |
1.90 |
1.90 |
1.90 |
EHDP (Dequest 2016D) |
0.246 |
0.246 |
0.246 |
0.246 |
antifoam |
0.40 |
0.40 |
0.40 |
0.40 |
Savinase 24GTT (protease) |
0 |
0 |
0.173 |
0.173 |
Lipex 100TB (lipase) |
0 |
0 |
0.10 |
0.10 |
Mannaway 4T (mannanase) |
0 |
0 |
0.82 |
0.082 |
Stainzyme Plus 12GT (amylase) |
0 |
0 |
0.1 |
0.10 |
Repelotex SF2 |
0.123 |
0.123 |
0.123 |
0.123 |
Dimorpholino Fluorescer Granular |
0.20 |
0.20 |
0.20 |
0.20 |
Blue Carbonate Speckles |
1.00 |
1.00 |
1.00 |
1.00 |
Moisture, Salts, NDOM |
2.87 |
2.87 |
2.87 |
2.87 |
TOTAL |
100.00 |
100.00 |
100.00 |
100 |
Table 2
|
Delta SRI |
LSD95p |
LSD95n |
Lipstick stain |
Control |
0.00 |
8.566 |
- 8.566 |
Comp A |
7.00 |
8.566 |
- 8.566 |
Comp B |
3.54 |
8.566 |
- 8.566 |
Ex 1 |
8.98 |
8.566 |
- 8.566 |
Tomato Ketchup stain |
Control |
0.00 |
0.774 |
-0.774 |
Comp A |
0.22 |
0.774 |
-0.774 |
Comp B |
0.63 |
0.774 |
-0.774 |
Ex 1 |
0.87 |
0.774 |
-0.774 |
[0091] The results in Table 2 clearly shows that the delta SRI of the preferred compositions
(Ex 1) having a specific bleach activator according to the present invention and enzyme
shows statistically significant improvement in removal of lipstick stain and tomato
ketchup stain when compared to the control composition and provides improved performance
as compared to the comparative compositions (Comp A, Comp B).