U.S. patent application number 10/488634 was filed with the patent office on 2005-01-27 for laundry compositions for use in a tumble dryer.
Invention is credited to Cooke, Deborah Jane, Felton, Julie, Finch, Timothy David.
Application Number | 20050020478 10/488634 |
Document ID | / |
Family ID | 9921493 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050020478 |
Kind Code |
A1 |
Cooke, Deborah Jane ; et
al. |
January 27, 2005 |
Laundry compositions for use in a tumble dryer
Abstract
A laundry treatment process, which comprises tumble drying
clothes in the presence of a chelating agent which has one nitrogen
atom and at least four carboxylic acid groups per molecule, or a
salt thereof. The preferred chelating agent being is a disuccinnic
acid or a salt thereof of the general formula
HOOC--(R.sub.1.COOH)R.sub.2--NR.sub.5--R.sub.3(R.s-
ub.4.COOH)--COOH wherein R1-R5 are preferably each independently,
C1-C5 alkyl, hydroxy-alkyl or hydrogen.
Inventors: |
Cooke, Deborah Jane;
(Wirral, GB) ; Felton, Julie; (Wirral, GB)
; Finch, Timothy David; (Wirral, GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Family ID: |
9921493 |
Appl. No.: |
10/488634 |
Filed: |
March 3, 2004 |
PCT Filed: |
August 30, 2002 |
PCT NO: |
PCT/EP02/09825 |
Current U.S.
Class: |
510/519 |
Current CPC
Class: |
C11D 17/047 20130101;
C11D 3/33 20130101; C11D 17/041 20130101 |
Class at
Publication: |
510/519 |
International
Class: |
D06L 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 4, 2001 |
GB |
0123941.1 |
Claims
1. Laundry treatment process, which comprises tumble drying clothes
in the presence of a chelating agent which has one nitrogen atom
and at least four carboxylic acid groups per molecule, or a salt
thereof.
2. Process according to claim 1, wherein the chelating agent is a
disuccinnic acid or a salt thereof.
3. Process according to claim 2 wherein the disuccinnic acid is
amine bridged.
4. Process according to claim 1 wherein the chelating agent is of
the general
formulaHOOC--(R.sub.1.COOH)R.sub.2--NR.sub.5--R.sub.3(R.sub.4.COO-
H)--COOHWherein R1-R5 are each independently, C1-C5 alkyl,
hydroxy-alkyl or hydrogen.
5. Process according to claim 4 wherein R1-R4 are methylene and R5
is hydrogen.
6. Process according to claim 1, conducted in the presence of one
or more of a fabric softening agent, fabric conditioning agent,
perfume, anti-static agent, dye-transfer inhibiting polymer, dye
fixing agent, other sequestrant, chlorine scavenging agent,
lubricants, cross-linking polymers, optical brightening agents.
7. Laundry treatment composition comprising a chelating agent which
has one nitrogen atom and at least four carboxylic acid groups per
molecule, or a salt thereof together with instructions to use in
the tumble drier.
8. Composition according to claim 7, in the form of a liquid, foam,
powder, sheet, deformable solid, gel, paste, film, breakable solid
or combination thereof
9. Composition according to claim 7 wherein the chelating agent is
of the general
formulaHOOC--(R.sub.1.COOH)R.sub.2--NR.sub.5--R.sub.3(R.sub.4.COO-
H)--COOHwherein R.sub.1-R.sub.5 are each independently,
C.sub.1-C.sub.5 alkyl, hydroxy-alkyl or hydrogen.
10. A laundry drier sheet comprising a substrate and a chelating
agent is of the general
formulaHOOC--(R.sub.1.COOH)R.sub.2--NR.sub.5--R.sub.3(R.su-
b.4.COOH)--COOHwherein R.sub.1-R.sub.5 are each independently,
C.sub.1-C.sub.5 alkyl, hydroxy-alkyl or hydrogen.
Description
TECHNICAL FIELD
[0001] The present invention relates to improvements to fabric
treatment compositions and a process for use of the same. It is
particularly concerned with a method and compositions for use with
a tumble drier.
BACKGROUND OF THE INVENTION
[0002] Sequestering agents have been used in detergents since
ancient times, when materials such as citric and tartaric acid were
employed to obtain clear products with good solubility. In
particular traces of metals such as ferric iron can cause
discoloration of textiles and it has long been known to use
sequestering agents, such as oxalic acid, to remove them.
[0003] In 1937, IG Farbenindustrie introduced the amino-carboxylic
acid sequestrants for use in the dyeing industry. It is well known
that traces of metals, particularly calcium, magnesium, iron,
copper and aluminium are often responsible for faulty dyeing. These
impurities can be present in a dye bath because of corrosion from
fittings, from the water used or as carry over from a previous
process. The difficulties that occur in the dyeing process are due
to the sensitivity of the dyestuffs to these trivalent and divalent
cations. Dyestuffs form less soluble salts with these metals and
this can lead to precipitation. Additionally, many dyestuffs
contain complexing groups which complex with metal ions and may
lead to changes in the solubility or colour of the dye. This latter
point is particularly true with the mordant dyes. Chrome dyes, on
the other hand intentionally chelate chromium and the replacement
of chromium with iron in the dyestuff leads to a disastrous change
of colour.
[0004] Almost everyone is aware that repeated laundering of clothes
will eventually cause most colours to fade or change in tint or
hue. Consequently, many products have been marketed under the
banner of `colour care`. The first of these merely omitted bleach
and other components which could damage colours. Later developments
have included the incorporation of agents to prevent dye loss or
dye transfer.
[0005] In certain ways, the environment within which laundering
processes occur is similar to that in a dyeing bath. Dyed fabric is
subjected to a combination of heat and water of variable purity and
it is to be expected that the presence of metal ions will cause
similar problems to those that occur in dyeing. In recent years, it
has been suggested that sequestrants can have benefits in the
laundering process.
[0006] The laundering process comprises a series of unit operations
of which several involve the wet treatment of fabrics. These can
include pre-soak and pre-treatment processes, as well as the more
commonplace washing/rinsing process. Often these washing and
rinsing processes are mechanised. Optional processing includes
machine-drying either by centrifuge or by the application of heat,
as in a so-called `tumble drier`. Treatment components can be added
at various stages, for example, with detergents being added in the
wash and conditioners being added in the rinse.
[0007] WO 2000/34427 discloses the use of the sequestrant IDS
(iminodisuccinic acid) at various stages within the laundry process
as part of a non-bleaching detergent composition containing IDS for
colour care and stain-removal benefits. U.S. Pat No. 5,686,376
discloses the possibility of adding sequestering agents in the
rinse to improve colour fidelity.
[0008] Instances of treatment in the drier are less common. Often,
treatment in the drier is restricted to the addition of perfume
(from a so-called `drier sheet`) although it is also possible to
treat fabrics with conditioners/softeners during this
operation.
[0009] U.S. Pat. No. 6,107,270 discloses dryer-added fabric
softener compositions that are said to provide colour and other
fabric benefits. Suggested sequestering agents include TPED
(Quadrol L), EDDS and NTA. U.S. Pat. No. 6,025,321 discloses
further dryer-added fabric softener composition to provide colour
and other fabric benefits, suggesting the same sequestering
agents.
[0010] Persistent staining and colour loss and/or change on fabrics
are major issues for many users of domestic detergent compositions.
There is therefore an ongoing need to find improved sequestering
agents and or the means for delivering them.
BRIEF DESCRIPTION OF THE INVENTION
[0011] We have determined that a particular group of sequestering
agents gives an improved colour benefit and indeed even a colour
restoration benefit when used in the tumble drier. It is believed
that this is in some way due to the removal of metal ions
associated with the fabrics either through staining or through an
earlier step in the laundry process.
[0012] It is believed that treatment with these materials prevents
further transition metal ion colour damage and that such treatment
can give stain removal benefits in the next wash.
[0013] The present invention provides a laundry treatment process,
which comprises tumble drying clothes in the presence of a
chelating agent which has one nitrogen atom and at least four
carboxylic acid groups per molecule, or a salt thereof.
[0014] The present invention also provides a laundry treatment
composition comprising a chelating agent which has one nitrogen
atom and at least four carboxylic acid groups per molecule, or a
salt thereof together with instructions to use in the tumble
drier.
[0015] The present invention also provides a laundry drier sheet
comprising a substrate and a chelating agent is of the general
formula
HOOC--(R.sub.1.COOH)
R.sub.2--NR.sub.5--R.sub.3(R.sub.4.COOH)--COOH
[0016] wherein R.sub.1-R.sub.5 are each independently, C1-C5 alkyl,
hydroxy-alkyl or hydrogen.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Preferred 1-N 4-COOH chelating agents are disuccinnic acids
containing a nitrogen hetero-atom. Preferred materials are
amine-bridged.
[0018] Preferably, the chelating agent is of the general
formula:
HOOC--(R.sub.1.COOH)R.sub.2--NR.sub.5--R.sub.3(R.sub.4.COOH)--COOH
(1)
[0019] wherein R1-R5 are each independently, C1-C5 alkyl,
hydroxy-alkyl or hydrogen. In this arrangement, two of the
carboxylic acid groups are disposed on either side of the bridging
nitrogen atom.
[0020] In a preferred embodiment, R1-R4 in the formula (1) are
methylene and R5 is hydrogen. A particularly preferred material is
therefore iminodisuccinnic acid or a salt thereof. The structure of
which is given below as formula (2).
HOOC--(CH.sub.2.COOH)CH--NH--CH(CH.sub.2.COOH)--COOH (2)
[0021] It is envisaged that the corresponding hydroxy acids can
also be used.
[0022] The process can be conducted in the presence of other fabric
treatment agents. These are preferably one or more of a fabric
softening agents, fabric conditioning agents, perfumes, anti-static
agents, dye-transfer inhibiting polymers, dye fixing agents, other
sequestrants, chlorine scavenging agents, lubricants, cross-linking
polymers, soil release polymers, and optical brightening
agents.
[0023] In its broadest aspect, compositions that embody the present
invention can be in the form of a liquid, gel, paste, foam, powder,
sheet, film, deformable solid, breakable solid or combination
thereof.
[0024] A particularly preferred form is that of the drier sheet.
Preferred sheets are non-woven, and are more preferably embossed. A
range of suitable materials are known including a polyester/rayon
(50:50 mix) in sheet form. Levels of sequestrant are typically such
that the weight of sequestrant is in the range 0.0005-1.0% wt of
the weight of cloth being placed in the drier.
[0025] In order that the invention may be further understood it
will be described below with reference to the following
non-limiting examples.
EXAMPLES
[0026] The reflectance versus wavelength profile of 1%, Direct Red
80 dyed, unfixed, woven, cotton fabric was measured using the large
aperture on a Texicon ICS Spectraflash 500.TM., (excluding the UV
below 420 nm). Sixteen measurements were taken (using 4 cloth
thicknesses over the Spectraflash aperture).
[0027] The Direct Red 80 dyed cotton fabric was obtained from
Campbell Hayward Ltd. (Springvale Works, Shawclough Rd. Waterfoot,
Rossendale, Lancs. BB4 9JZ) and was not made up into garments.
[0028] The fabric was then washed twice in demineralised water
containing transition metal and water hardness ions at the
following concentrations: 1.1 ppm Cu.sup.2+: 2.0 ppm Fe.sup.3+:
0.12 ppm Mn .sup.2+: 2.3 ppm Zn.sup.2+. The levels selected are
quoted in the literature as being representative of the transition
metal ion levels found in the main wash for soiled loads (Patent
WO9403553). Water hardness was: 4.degree. FH Ca.sup.2+: 2.degree.
FH Mg.sup.2+
[0029] Washing was performed in a vertical axis (US) machine
(Whirlpool.TM. Super Capacity Plus Washer) set for a 12 min wash on
a small load setting. Two applications of transition metal ions
were performed in order to damage the fabric by transition metal
ion deposition. This has the effect of changing the hue of the
fabric, to give a visible blue tinge. The fabric was dried in a
tumble dryer (Whirlpool.TM. Super Capacity Dryer) after each
wash.
[0030] The change in colour of the `colour-damaged` fabric when
treated with chelating agents, provides a sensitive measure of
their efficacy. For these experiments, this fabric was cut into 20
cm.sup.2 swatches and overlooked. The reflectance versus wavelength
profile of these swatches was measured using the large aperture on
a Texicon ICS Spectraflash 500.TM., (excluding the UV below 420 nm)
to obtain a comparative measure of damage compared to the new
fabric. Here, 4 measurements were taken per swatch, using 4 cloth
thicknesses over the Spectraflash aperture. Five swatches were used
per drying experiment. The swatches were rewet using demineralised
water, prior to mixing in with a wet ballast load, containing white
non-mercerised, desized woven cotton. The ballast had previously
been put through a rinse cycle with demineralised water.
Examples 1-5 and Comparatives
[0031] The dose response characteristic of IDS was investigated
using the IDS concentrations (% on total weight of fabric in the
load) given in table 1 below.
[0032] To obtain these results a Miele Novotronic.TM. T454 tumble
dryer was allowed to warm up on "extra dry cotton" heat setting for
5 min.
[0033] A nonwoven, embossed, polyester/rayon (50:50 mix) sheet (95
gm.sup.-2) was loaded with 62.5 g of IDS liquid sequestrant
(Iminodisuccinic acid, tetrasodium salt, 40% activity ex. Nippon
Shokubai). This corresponds to 1% IDS on weight of fabric for a 2.5
kg load. The IDS solution was spread out evenly over the sheet,
using a glass rod. The sheet was placed inside the dryer, with the
2.5 kg fabric load comprising white, desized, non-mercerised,
cotton ballast +five 20.times.20 cm `colour damaged`, Direct Red
80, overlocked, cotton test swatches. The load was dried on the
extra dry cotton heat setting.
[0034] Once the load was dry, the test swatches were removed from
the tumble dryer and the reflectance versus wavelength profile was
measured for each using the large aperture on a Texicon ICS
Spectraflash 500.TM., (excluding the UV below 420 nm). Four
measurements were taken per cloth (using 4 cloth thicknesses over
the Spectraflash aperture) giving a total of 20 readings per wash
load. This experiment was repeated for separate wash loads using
concentrations of 0.5%, 0.1%, 0.01 and 0.005% IDS on weight of
fabric based on a 2.5 kg load. N.B. The total volume of IDS
solution added onto the sheet was kept constant at 62.5 g.
[0035] The experiment was performed twice for each IDS
concentration, giving a total of 40 reflectance readings per
concentration. The average reflectance reading at 620 nm for each
concentration is quoted in Table 1.
[0036] Comparison of the reflectance profiles showed that the
reflectance value at 620 nm was found to be the most sensitive
wavelength for measuring differences in the sequestering capability
of the IDS for ions on the fabric surface. The results from the
dose response experiment at 620 nm are shown below in Table 1. (95%
confidence limits were calculated for the experiment using the
Excel.TM. statistical analysis tool.)
1TABLE 1 Dose Response for IDS Mean Reflectance Standard Confidence
Example Treatment at 620 nm Deviation Limits Comparative A Unwashed
46.56 -- -- Comparative B Damaged 35.99 -- -- Comparative C 0% IDS
37.92 1.70 1.49 1 0.005% IDS 39.84 2.71 1.68 2 0.01% IDS 43.68 2.72
1.69 3 0.1% IDS 49.64 4.21 2.61 4 0.5% IDS 54.98 0.88 0.54 5 1% IDS
53.89 1.86 1.15
[0037] From these results it can be seen that washing fabric in the
presence of the metal ions causes a significant lowering of
reflectance at this wavelength (compare comparative A with B). Some
of this loss can be recovered by wetting and drying the fabric with
demineralised water (compare comparative B with C). However, it can
be seen that the presence of even low levels of IDS causes a
significant improvement in the recovery of mean reflectance.
Examples 6 and Comparatives
[0038] A level of 0.01% sequestrant was chosen for the
investigation into the relative performances between the
sequestrants listed below:
[0039] a) TPED (N, N, N', N' tetrakis (2-hydroxy propyl)
ethylenediamine: available as Quadrol.TM. L, 100% activity, ex
BASF).
[0040] b) EDDS (ethylene diamine disuccinic acid tri sodium salt:
available as Octaquest E30.TM. ex Octel 32.7%)
[0041] c) NTA (Nitrilotriacetic acid sodium salt monohydrate 99% ex
Aldrich).
[0042] The method used was the same as that used for examples 1-5.
Results are given in table 2 below:
2TABLE 2 Comparison with other sequestrants Mean Mol. Ref. at Std.
95% Example Treatment Wt. 620 nm Deviation Conf. Comparative A
Unwashed -- 46.56 0.16 0.16 Comparative B Damaged -- 35.99 0.29
0.28 Comparative C 0% IDS -- 37.92 1.70 1.49 6 0.01% IDS 337.1
43.68 2.72 1.69 Comparative D 0.01% EDDS 358 40 3.02 1.87
Comparative E 0.01% TPED 292.42 40 1.70 1.05 Comparative F 0.01%
NTA 257 39 3.9 2.42
[0043] From these results it can be shown that the IDS sequestrant
shows statistically better performance at equivalent weight (0.01%)
than the other sequestrants (TPED, EDDS and NTA, comparatives
D-F).
Example 7 and Comparatives
[0044] Woven fabric dyed with 1% Direct Red 80 (unfixed) was
obtained from Campbell Hayward Ltd. (Springvale Works, Shawclough
Rd. Waterfoot, Rossendale, Lancs. BB4 9JZ)
[0045] The reflectance versus wavelength profile was measured for
the new fabric using the large aperture on a Texicon ICS
Spectraflash 500.TM., (excluding the UV below 420 nm). Sixteen
measurements were taken (using 4 cloth thicknesses over the
Spectraflash aperture).
[0046] The red woven fabric was treated with transition metal ions
as follows:
[0047] The fabric was washed twice in demineralised water
containing transition metal and water hardness ions at the
following concentrations: 1.1 ppm Cu.sup.2+: 2.0 ppm Fe.sup.3+:
0.12 ppm Mn.sup.2+: 2.3 ppm Zn.sup.2+. The levels selected are
quoted in literature (WO9403553) as being representative of the
transition metal ion levels found in the main wash when soiled
loads are used. Water hardness was: 4.degree. FH Ca.sup.2+:
2.degree. FH Mg.sup.2+
[0048] Washing was performed in a vertical axis (US) machine
(Whirlpool.TM. Super Capacity Plus Washer) set for a 12 min wash on
a small load setting. Two applications of transition metal ions
were performed in order to damage the fabric by transition metal
ion deposition. This has the effect of changing the hue of the
fabric, to give a visible blue tinge. The fabric was dried in a
tumble dryer (Whirlpool.TM. Super Capacity Dryer) in between each
wash.
[0049] The change in colour of the `colour-damaged` fabric when
treated with chelating agents, provides a sensitive measure of
their efficacy. For these experiments, this fabric was cut into 20
cm.sup.2 swatches and overlooked. The reflectance of these swatches
was measured to obtain a comparative measure of damage. The
reflectance versus wavelength profile was measured for the
`colour-damaged` fabric using the large aperture on a Texicon ICS
Spectraflash 500.TM., (excluding the UV below 420 nm). Sixteen
measurements were taken (using 4 cloth thicknesses over the
Spectraflash aperture)
[0050] Six (20.times.20 cm) overlooked swatches of the
`colour-damaged` woven fabric dyed with 1% Direct Red 80 (unfixed)
were taken, dampened with demineralised water and mixed randomly
into a 2.5 kg ballast load (white, desized, non-mercerised woven
cotton sheeting) which had previously been put through a rinse
cycle with demineralised water.
[0051] Sequestrants used were:
[0052] TPED: N, N, N', N' tetrakis (2-hydroxy propyl)
ethylenediamine: available as Quadrol.TM. L, 100% activity, ex
BASF.
[0053] EDDS: Ethylene diamine disuccinic acid tri sodium salt:
available as Octaquest E30.TM. ex Octel 32.7%.
[0054] NTA: Nitrilotriacetic acid sodium salt monohydrate 99% ex
Aldrich.
[0055] IDS: Iminodisuccinic acid tetra sodium salt (ex Nippon
Shokubai Co. Ltd 40.2% aqueous solution)
[0056] Moles of all sequestrants used in experiment =2.14e.sup.-3
moles.
[0057] A 50 ml solution of 2.14e .sup.-3 moles IDS in demineralised
water was prepared. A nonwoven, embossed, polyester/rayon (50:50
mix) sheet (95 gm.sup.-2) was loaded with the 50 g IDS sequestrant
solution described above. The IDS solution was spread out evenly
over the sheet, using a glass rod.
[0058] A US Whirlpool.TM. Super Capacity Dryer was allowed to warm
up for 5 minutes on permanent press/heavy setting. The tumble dryer
sheet that had been loaded with IDS was then placed inside the
dryer, with the 2.5 kg fabric load (ballast +6 test swatches). The
load was dried using the permanent press/heavy setting for 90
minutes.
[0059] The process was repeated again with a separate, identical
load.
[0060] The entire regime was repeated with the other sequestrants,
TPED, NTA and EDDS.
[0061] The reflectance versus wavelength profile was measured for
the treated fabrics using the large aperture on a Texicon ICS
Spectraflash 500.TM. (excluding the UV below 420 nm). Four
measurements were taken for each piece of fabric in each load using
4 cloth thicknesses over the Spectraflash aperture. This gave 24
measurements per load and 48 readings per treatment.
[0062] The reflectance value of the coloured fabric at 620 nm is
the most sensitive to the effects of transition metal ions in this
system. The changes in reflectance at 620 nm for the fabric after
treatment with the various sequestrants are shown below (in table
3) for comparison.
3TABLE 3 Comparison with other sequestrants at equimolar
concentration (2.14 .times. 10-3 moles). Mean 95% reflectance
Standard confidence Treatment at 620 nm Deviation Limits Unwashed
46.56 0.16 0.16 Damaged 35.99 0.29 0.28 IDS 44.03 4.48 1.27 TPED
38.23 1.11 0.31 EDDS 39.41 2.99 0.85 NTA 38.45 1.71 0.48
[0063] From these figures it can be seen that the IDS containing
system is significantly better than the other materials at the
concentration used.
* * * * *