[0001] The present invention relates to fabric washing processes and to the compositions
which are adapted for this purpose, using synthetic detergent active compounds together
with phosphate detergency builders. The invention concerns in particular fabric washing
using detergent compositions which contain levels of the phosphate detergency builders
which can be lower than conventional phosphate builder levels, whilst still achieving
good detergency results.
[0002] It is known to include polymer phosphates as builders in detergent compositions.
In US 4 113 644 (Ashcraft) there is described a polymer phosphate granulated with
a material such as polyethylene glycol to improve its stability to degradation. These
granules are used in detergent compositions containing high levels of phosphate detergency
builders, particularly high levels of pyrophosphate.
[0003] It is also known to wash fabrics in two steps. Thus GB 996 193 (Henkel) describes
adding a first concentrate to water to form a wash liquor and subsequently adding
a second concentrate to the same liquor. By suitable choice of components in these
concentrates enhanced bleaching of fabrics can be obtained.
[0004] The present invention on the other hand is concerned with low phosphorus containing
compositions having enhanced building properties.
[0005] According to a first aspect of the invention, there is provided a process for washing
fabrics comprising the steps of:
(i) contacting the fabrics with a wash liquor containing a synthetic detergent active
compound and an alkalimetal or ammonium orthophosphate; and
(ii) subsequently contacting the fabrics with a wash liquor containing a synthetic
detergent active compound and an alkalimetal or ammonium polymer phosphate, each of
said wash liquors having a pH between 8 and 12 and each of said wash liquors containing
substantially no other phosphate detergency builders, characterised in that step (ii)
is carried out at least 15 seconds after step (i).
[0006] The process can be conducted if desired in two stages, for example using a prewash
as step (i) and then a main wash as step (ii), the fabrics being substantially separated
from the prewash liquor before being contacted with the main wash liquor. In this
event there is often some carry-over of the ingredients in the pre-wash into the main
wash, so that there is some benefit from the presence of residual alkalimetal orthophosphate
in the main wash liquor. Many modern domestic washing machines are designed for sequential
pre- and main washes, or the consumer may himself arrange the sequential washing.
[0007] Alternatively, the washing process can be conducted in a single stage, where the
liquor used in step (i) remains in contact with the fabrics during step (ii). This
can be achieved by including the polymer phosphate together with the orthophosphate
and synthetic detergent compound in a single composition, but treating the former
to delay its dissolution so that in step (i) it remains in an undissolved form, or
by adding the polymer phosphate to the wash solution later than the other ingredients.
This can again be achieved manually or automatically. Dissolution of the polymer phosphate
is desirably delayed for at least a quarter of a minute, preferably at least one and
more preferably, at least five minutes, after dissolution of the bulk of the orthophosphate,
to encourage maximum precipitation of calcium orthophosphate before addition of the
former.
[0008] According to the second aspect of the invention there is provided a detergent composition
for carrying out such a method, comprising a synthetic detergent active compound,
an alkalimetal or ammonium orthophosphate and an alkalimetal or ammonium polymerphosphate,
said composition yielding a pH of between 9 and 11 when dissolved in 12°H (Ca) water
(French permanent hardness, calcium only) at 50°C and at a concentration of 0.1% w/v,
and said composition containing not more than 5% by weight alkali metal pyrophosphate
by weight of the composition and substantially no other phosphate detergency builders,
characterised by means for delaying the solubility of said alkalimetal or ammonium
polymer phosphate when the composition is added to water to form a wash liquor.
[0009] The detergent composition may be in the form of two containers, the first container
containing at least a part of said synthetic detergent active compound and the orthophosphate
and the second container containing the polymer phosphate and optionally a further
part of the synthetic detergent active compound. In use, the contents of the first
container are released into water to form a wash liquor for step (i) of the process
and subsequently the contents of the second container are released to form a wash
liquor for step (ii) of the process.
[0010] The delayed addition of the polymer phosphate to the washing solution is advantageous
in giving decreased deposition of inorganic phosphates on the washed fabric, compared
with the simultaneous addition of the polymer phosphate and orthophosphate. It is
believed that this is due to the substantially complete precipitation of calcium orthophosphate
by reaction with hard water before dissolution of the polymer phosphate. This, in
turn, appears to lead to decreased hydrolysis of the polymer phosphate, compared with
the amount of hydrolysis which takes place when the water had not been pre-softened
in this way; one of the products of hydrolysis is alkali metal or ammonium pyrophosphate
which apparently causes high levels of inorganic deposition on the washed fabric,
and hence the control of the rate of hydrolysis of the polymer phosphate as proposed
leads to decreased fabric deposits.
[0011] The washing process of the invention can be accomplished manually, if desired, but
is normally accomplished in a domestic or commercial laundry washing machine. The
latter permits the use of higher wash temperatures and alkalinity, and more effective
agitation, all of which contribute generally to better detergency. High wash temperatures
(at least about 60°C) and high alkalinity (over about pH 10) also particularly assist
the precipitation of the calcium orthophosphate to achieve more effective water softening.
However, any wash temperature between ambient and boiling may be employed with any
normal degree of alkalinity (pH 8-12). The type of washing machine used, if any, is
not significant.
[0012] It is preferred to accomplish the washing process in the joint presence of both the
orthophosphate and the polymer phosphate, but with the dissolution of the latter being
delayed, as described above. This has the advantage of combining the water-softening
action of both phosphates. This means, referring to the process of the invention,
that the first aqueous solution is used to prepare the second aqueous solution. An
added advantage is that the detergent active compound used in both solutions can then
be the same substance or mixture of substances.
[0013] It should be appreciated that when in aqueous solution in hard water, the orthophosphate
and the polymer phosphate will be present wholly or partially in the form of the calcium
or magnesium salts, which are insoluble for the orthophosphates and soluble chelates
in the case of the polymer phosphates. But for convenience the phosphates will be
referred to generally as being in the alkali metal or ammonium salt form as appropriate,
as if the aqueous solutions were prepared with de-ionised water.
[0014] The detergent compositions used in the process of the invention may be either solid
or liquid compositions. Either physical form can be used if the orthophosphate and
polymer phosphate are included in different compositions for separate addition to
the wash liquor. Compositions in liquid form are suitable in particular for commercial
laundry use, in which bulk supplies of aqueous orthophosphate and polymer phosphate
solutions are available and are automatically dosed to the washing machines at the
appropriate times in the wash cycle. But if the orthophosphate and polymer phosphate
are included in a single composition, with the latter being treated to delay its solubility,
the composition will normally be in solid form, e.g. as a powdered or granulated product.
[0015] Suitable processes for the preparation of such detergent compositions according to
the invention include forming a detergent base powder containing a detergent active
compound or compounds and optionally the orthophosphate, and admixing with the base
powder any further orthophosphate and an alkali metal or ammonium polymer phosphate,
treated to delay its dissolution in water. Preferably the base powder is prepared
by spray drying in the normal way using conventional equipment and process conditions.
However, other conventional techniques may be used for preparing the base powder containing
the detergent active compound and usually the orthophosphate. Other heat-sensitive
ingredients may also be admixed with the base powder together with or separately from
the treated alkali metal or ammonium polymer phosphate, for example oxygen bleach
compounds such as sodium perborate.
[0016] The alkali metal polymer phosphate used in the compositions of the invention is preferably
a sodium polymer phosphate, but if desired the potassium or ammonium salts can be
used. For convenience the term alkali metal polymer phosphate is used below to include
the sodium, potassium and ammonium salts. The alkali metal polymer phosphates are
generally represented as having the formula M
20(MP0
3)
", where M is sodium, potassium or ammonium and n is an integer which is at least 4
and up to 100 or more, preferably where n is from 6 to 50. In the case of the latter
sodium polymer phosphates, these figures correspond to a P
20, content of from 60.4% by weight up to a theoretical maximum of 69.6%, preferably
63% to 69% P
20, by weight of the polymer phosphates. To be effective the polymer phosphates must
be water-soluble, although the rate of solution decreases at the longer chain lengths.
It should be appreciated that the chemical structures of the polymer phosphates are
not precisely defined, and some degree of ring formation or branching may be present
in the otherwise normally linear polymer structure, especially with the shorter polymer
chain lengths. The higher polymer phosphates are sometimes also known as glassy phosphates
or Graham's salt.
[0017] If the polymer phosphate is treated to delay its dissolution, for inclusion in a
single composition with the orthophosphate, this may be accomplished in the production
of the polymer phosphate or subsequently. Specifically, the polymer phosphates may
be made with a large particle size and with a particular long-chain length, for example
where n is 50-100 or more, or the polymer phosphate may be coated or encapsulated
with a slowly soluble material such as wax, nonionic detergent compounds, higher fatty
acids or a protein such as gelatin. The rate of solubility of the polymer phosphates
may also be decreased by using them in partial calcium, zinc or other polyvalent salt
form. Two or more of these treatments may also be combined, so as to give close control
over the solubility of the polymer phosphate under the recommended washing conditions.
[0018] The rate of solubility of the polymer phosphate may also be controlled by granulating
the polymer phosphate with sodium silicate. Specifically, the granules may contain
the polymer phosphate and an alkalimetal silicate having a M
20:S'0
2 ratio of from 1:2 to 1:3.75 wherein M is an alkalimetal, the granule being dried
to a moisture content of less than 7% by weight. A particularly useful granule of
this type can be achieved by granulating 1 part of polymer phosphate with 3 parts
of sodium silicate having an Na
2o:S'0
2 ratio of 1:2. The polymer phosphate-containing granule may also contain a portion
of the synthetic detergent active compound.
[0019] US 4 040 988 (Benson) describes granules formed by sequestering builders and alkalimetal
silicates and may be referred to in this connection.
[0020] The delayed solubility of the polymer phosphate may also be achieved by dosing the
composition in a two-compartment sachet, the sachet being so constituted that when
added to water the contents of the first compartment, namely the alkalimetal orthophosphate
and at least some of the synthetic detergent active compound are released before the
contents of the second compartment, namely the alkalimetal or ammonium polymer phosphate
and optionally a further part of the synthetic detergent active compound.
[0021] A suitable sachet construction of this type may be made from a first outer sheet
of polyethylene film, a second outer sheet of acrylic bonded polyester/viscose non-woven
fabric and an inner sheet of thermally bonded polypropylene non-woven fabric, these
three sheets being heat sealed together at the edges to define a sachet with two compartments.
Before sealing the final edge, the first compartment between the two layers of non-woven
fabric may be filled with the orthophosphate and at least some of the synthetic detergent
active compound. The second compartment may be filled with the alkalimetal or ammonium
polymer phosphate and optionally a further part of the synthetic detergent active
compound.
[0022] In use the contents of the second compartment are released after those of the first
compartment because they must pass through the first compartment before entering the
wash liquor.
[0023] The solution of the polymer phosphate may also be delayed by coating or encapsulating
the polymer phosphate with a water-dispersible water-insoluble material or with a
water-soluble material. Examples of such coating materials include fatty acids, alkanolamides
of fatty acids, glycerol esters of fatty acids, long chain hydrocarbon aliphatic alcohols,
paraffin waxes, mineral oil, gelatin, sugar, nonionic surface active agents, polyvinylalcohol
and sodium carboxymethylcellulose as described in US 3 847 830 (Williams) and GB 1
242 247 (Unilever).
[0024] The orthophosphate used is either potassium or preferably sodium orthophosphate,
as the latter is cheaper and more readily available. Ammonium orthophosphate may also
be used, particularly if the product is not prepared by spray drying. Normally the
tri-alkali metals salts are used, but orthophosphoric acid or the di- or mono-alkalimetal
salts, e.g. disodium hydrogen orthophosphate or monosodium dihydrogen orthophosphate
could be used if desired in the production of the compositions. In the latter event
other more alkaline salts should also be present to maintain a high pH in the end
product, i.e. with full neutralisation to the tri-alkalimetal orthophosphate salts.
The use of a mixture of mono-sodium dihydrogen and disodium hydrogen orthophosphates
in the ratio of 1:3 to 2:3, especially about 1:2, is particularly advantageous, as
such a mixture (known as kiln-feed) is made in the production of sodium tripolyphosphate
and is readily available.
[0025] The orthophosphate can be used in the form of the anhydrous or hydrated salts, but
in the former case it is preferred to promote hydration during processing, e.g. by
adding the anhydrous orthophosphate to a detergent slurry and spray drying to form
a base powder. The alkalimetal polymer phosphates do not form hydrated salts as such,
and are normally used in predominantly anhydrous form, but they are hygroscopic and
tend to absorb atmospheric moisture. The amounts of salts used are expressed in anhydrous
form.
[0026] The total amounts of the essential polymer phosphate and orthophosphate are chosen
according to the overall detergency builder level which is desired in the detergent
compositions or according to the maximum permitted phosphorus content. Normally, when
both the orthophosphate and polymer phosphate are present in a single composition,
the total phosphate builder level, which is preferably derived solely from the polymer
phosphate and the orthophosphate, is between 5% and 50%, preferably 10% to 30% by
weight of the composition, with an amount of 2% to 20% each of the polymer phosphate
and orthophosphate. Preferably the amounts of the polymer phosphate and the orthophosphate
are each from 5% to 15%, especially 5% to 10% by weight of the polymer. The total
amount of the polymer phosphate and orthophosphate is preferably from 10% to 25%,
especially 15% to 20%, by weight of the composition.
[0027] It is generally preferred to have amounts of the orthophosphate and the polymer phosphate,
within the ratio of from 3:1 to 1:3 especially 2:1 to 1:2, parts by weight. These
ratios of polymer phosphate to orthophosphate are particularly suitable for detergent
compositions used at relatively high product concentrations, i.e. 0.3% to 0.8% by
weight as is common practice in Europe, especially in front-loading automatic washing
machines, and where moderate levels of phosphates are allowed in the products, i.e.
equivalent to 2% to 7% P.
[0028] The only phosphate detergency builders used in the process of the invention should
be the polymer phosphate and the orthophosphate. In particular, it is desirable to
use no alkalimetal, i.e. sodium or potassium, pyrophosphates in the compositions as
this tends to increase inorganic deposition as mentioned above.
[0029] Some pyrophosphate is generally found as impurities at low levels in other commercial
alkali metal phosphates, and some pyrophosphate may also be formed by hydrolysis of
any polymer phosphate during processing, for example during slurry making. Hence,
total absence of alkali metal pyrophosphate is generally unattainable in the detergent
compositions. Not more than 5% especially not more than 2.5% of alkali metal pyrophosphate
should be present in the compositions, as at higher levels the amounts of inorganic
deposits on the washing machine parts become significantly more noticeable.
[0030] The process of the invention is necessarily accomplished using synthetic anionic,
nonionic, amphoteric or zwitterionic detergent active compounds or mixtures thereof.
Detergent compositions normally include from 2.5% to 50%, preferably 5% to 30%, and
especially 10% to 25% by weight of such ingredients. Many suitable detergent compounds
are commercially available and are fully described in the literature, for example
in "Surface Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and
Berch.
[0031] The preferred detergent compounds which can be used are synthetic anionic and nonionic
compounds. The former are usually 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 being used to include the alkyl portion of higher acyl radicals. Examples
of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates,
especially those obtained by sulphating higher (C
8―C
18) alcohols produced for example from tallow or coconut oil; sodium and potassium alkyl
(C
9―C
20) benzene sulphonates, particularly sodium linear secondary alkyl (C
10-C
15) benzene sulphonates; sodium alkyl glyceryl ether sulphates, especially those ethers
of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived
from petroleum; sodium coconut oil fatty monoglyceride sulphates and sulphonates;
sodium and potassium salts of sulphuric acid esters of higher (C
9―C
18) fatty alcohol-alkylene oxide, particularly ethylene oxide, reaction products; the
reaction products of fatty acids such as coconut fatty acids esterified with isethionic
acid and neutralised with sodium hydroxide; sodium and potassium salts of fatty acid
amides of methyl taurine; alkane monosulphonates such as those derived by reacting
alpha-olefins (C
B-C
20) with sodium bisulphite and those derived from reacting paraffins with S0
2 and CI
2 and then hydrolysing with a base to produce a random sulphonate; and olefin sulphonates,
which term is used to describe the material made by reacting olefins, particularly
C
10―C
20 alpha-olefins, with S0
3 and then neutralising and hydrolysing the reaction product. The preferred anionic
detergent compounds are sodium (C
11―C
15) alkyl benzene sulphonates and sodium (C
18―C
18) alkyl sulphates.
[0032] Suitable nonionic detergent compounds which may be used include in particular 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. Specific nonionic
detergent compounds are alkyl (C
r-C
22) phenols- ethylene oxide condensates, generally 5 to 25 EO, i.e. 5 to 25 units of
ethylene oxide per molecule, the condensation products of aliphatic (C
8―C
18) primary or secondary linear or branched alcohols with ethylene oxide, generally
6 to 30 EO, and products made by condensation of ethylene oxide with the reaction
products of propylene oxide and ethylenediamine. Other so-called nonionic detergent
compounds include long chain tertiary amine oxides, long chain tertiary phosphine
oxides and dialkyl sulphoxides.
[0033] Mixtures of detergent compounds, for example mixed anionic or mixed anionic and nonionic
compounds may be used in the detergent compositions, particularly in the latter case
to provide controlled low sudsing properties. This is beneficial for compositions
intended for use in suds-intolerant automatic washing machines. We have also found
that the use of some nonionic detergent compounds in the compositions decreases the
tendency of insoluble phosphate salts to deposit on the washed fabrics, especially
when used in admixture with some soaps as described below.
[0034] Amounts of amphoteric or zwitterionic detergent compounds can also be used in the
compositions of the invention but this is not normally desired due to their relatively
high cost. If any amphoteric or zwitterionic detergent compounds are used in it is
generally in small amounts in compositions based on the much more commonly used synthetic
anionic and/or nonionic detergent compounds. For example, mixtures of amine oxides
and ethoxylated nonionic detergent compounds can be used.
[0035] Soaps may also be present in the detergent compositions of the invention, but not
as the sole detergent compounds. The soaps are particularly useful at low levels in
binary and ternary mixtures, together with nonionic or mixed synthetic anionic and
nonionic detergent compounds, which have low sudsing properties. The soaps which are
used are the sodium, or less desirably potassium, salts of C
lo-C
14 fatty acids. It is particularly preferred that the soaps should be based mainly on
the longer chain fatty acids within this range, that is with at least half of the
soaps having a carbon chain length of 16 or over. This is most conveniently accomplished
by using soaps from natural sources such as tallow, palm oil or rapeseed oil, which
can be hardened if desired, with lesser amounts of other shorter chain soaps, prepared
from nut oils such as coconut oil or palm kernel oil. The amount of such soaps can
be up to about 25% by weight, with lower amounts of about 0.5% to about 5% being generally
sufficient for lather control. Amounts of soap between about 2% to about 20%, especially
between about 5% and about 15%, can advantageously be used to give a beneficial effect
on detergency and reduced levels of incrustation.
[0036] Apart from the essential detergent active compounds and detergency builders, the
detergent compositions used in the process of the invention can contain any of the
conventional additives in the amounts in which such materials are normally employed
in fabric washing detergent compositions. Examples of these additives include lather
boosters such as alkanolamides, particularly the monoethanolamides derived from palm
kernel fatty acids and coconut fatty acids, lather depressants such as alkyl phosphates,
waxes and silicones, antiredeposition agents such as sodium carboxymethylcellulose
and polyvinyl pyrrolidone optionally copolymerised with vinyl acetate, oxygen- releasing
bleaching agents such as sodium perborate and sodium percarbonate, per-acid bleach
precursors, chlorine-releasing bleaching agents such as trichloroisocyanuric acid
and alkali metal salts of dichloroisocyanauric acid, fabric softening agents, inorganic
salts such as sodium sulphate, sodium carbonate and magnesium silicate, and, usually
present in very minor amounts, fluorescent agents, perfumes, enzymes such as proteases
and amylases, germicides and colourants.
[0037] It is particularly beneficial to include in the detergent compositions an amount
of sodium perborate, preferably between about 10% and 40%, for example about 15% to
about 30%, by weight. It has been found that the bleaching action of sodium perborate
is boosted under the highly alkaline conditions which also give optimum detergency
and building action from the orthophosphate. Thus, it becomes possible to achieve
improved bleaching properties by using the same levels of sodium perborate as normal;
or decreased levels of sodium perborate can be used to give equal bleaching properties
to those of conventional products with higher levels of perborate and sodium tripolyphosphate
as the sole detergency builder. The latter option can also be used to further decrease
the raw materials costs of the compositions, if a cheap filler is used in place of
part of the sodium perborate.
[0038] It is desirable to include one or more antideposition agents in the detergent compositions
of the invention, to decrease the tendency to form inorganic deposits on washed fabrics.
It appears that the effective antideposition agents are materials which stabilise
insoluble calcium orthophosphate particles and thereby inhibit their deposition onto
the fabrics. The most effective antideposition agents are anionic polyelectrolytes,
especially polymeric aliphatic carboxylates. The amount of any such antideposition
agent can be from about 0.01 % to about 10% of the compositions, but is normally from
about 0.1% to about 5% by weight, preferably from about 0.2% to about 2% by weight
of the compositions.
[0039] Specific preferred antideposition agents are the alkali metal or ammonium, preferably
the sodium, salts of homo- and co-polymers of acrylic acid or substituted acrylic
acids, such as sodium polyacrylate, the sodium salt of copolymethacrylamide/acrylic
acid and sodium poly-alphahydroxyacrylate, salts of copolymers of maleic anhydride
with ethylene, acrylic acid vinylmethylether, allyl acetate or styrene, especially
1:1 copolymers, and optionally with partial esterification of the carboxyl groups.
Such copolymers preferably have relatively low molecular weights, e.g. in the range
of about 1,000 to 50,000. Other anti-deposition agents include the sodium salts of
polymaleic acid, polyitaconic acid and polyaspartic acid, phosphate esters of ethoxylated
aliphatic alcohols, polyethylene glycol phosphate esters, and certain phosphates such
as sodium ethane - 1 - hydroxy - 1,1 - diphosphonate, sodium ethylenediamine tetramethylene
phosphonate, and sodium 2-phosphonobutane tricarboxylate. Mixtures of organic phosphonic
acids or substituted acrylic acids or their salts with protective colloids such as
gelatin may also be used. The most preferred antideposition agent is sodium polyacrylate
having a MW of about 10,000 to 50,000, for example about 20,000 to 30,000.
[0040] It is also possible to include in the detergent compositions of the invention minor
amounts, preferably not more than about 20% by weight, of other non-phosphate detergency
builders or sequesterant builders. This is of particular benefit where it is desired
to increase detergency whilst using particularly low levels of the essential polymer
phosphate and orthophosphate builders, so as to achieve especially low phosphorus
contents in the detergent compositions. Examples of such other detergency builders
are amine carboxylates such as sodium nitrilotriacetate, sodium carbonate, sodium
amorphous or crystalline aluminosilicate ion-exchange materials, sodium citrate and
soap, which can function as a detergency builder, as discussed above. However, such
other builder materials are not essential and it is a particular benefit of using
the mixed polymer phosphate and orthophosphate that satisfactory detergency properties
can be achieved at lower total phosphate levels than hitherto considered necessary
without other detergency builders.
[0041] It is generally also desirable to include in the compositions an amount of an alkali
metal silicate, particularly sodium ortho-, meta- or preferably neutral or alkaline
silicate. The presence of such alkali metal silicates at levels of at least about
1 %, and preferably from about 5% to about 15%, by weight of the composition, is advantageous
in decreasing the corrosion of metal parts in washing machines, besides giving processing
benefits and generally improved powder properties. The more highly alkaline ortho-
and meta-silicates would normally only be used at lower amounts within this range,
in admixture with the neutral or alkaline silicates.
[0042] The compositions of the invention are required to be alkaline, but not too strongly
alkaline as this could result in fabric damage and also be .hazardous for domestic
usage. In practice the compositions should normally give a pH of from 9 to 11 in use
in aqueous wash solution. It is preferred in particular for domestic products to have
a minimum pH of at least 9.25 and especially a pH of 9.5 or over, as lower pHs tend
to be less effective for optimum detergency building, and a maximum pH of 10.5, as
more highly alkaline products can be hazardous if misused. The pH is measured at the
lowest normal usage concentration of 0.1% w/v of the product in water of 12°H (Ca),
(French permanent hardness, calcium only) at 50°C so that a satisfactory degree of
alkalinity can be assured in use at all normal product concentrations.
[0043] The pH of the detergent compositions in use is controlled by the amount of orthophosphate
and any other alkaline salts such as alkali metal silicate, sodium perborate and sodium
carbonate present. The presence of such other alkaline salts, especially the alkalimetal
silicates, is particularly beneficial, because the alkalinity of the alkalimetal orthophosphate
is diminished in hard water due to precipitation of the calcium salt. In addition
the alkalimetal polymer phosphate is more stable and resistant to hydrolysis under
moderately alkaline conditions. The other ingredients in the alkaline detergent compositions
of the invention should of course be chosen for alkaline stability, especially the
pH sensitive materials such as enzymes.
[0044] The detergent compositions of the invention are preferably made in particulate form,
by admixture of a spray dried base powder and treated alkalimetal polymer phosphate.
However, if desired, the detergent compositions may be compressed or compacted into
tablets or blocks, or otherwise treated for example by granulation, prior to packaging
and sale. Because of the hygroscopic nature of the alkalimetal polymer phosphates,
it may be desirable to use moisture impermeable packaging for the detergent compositions,
for example in plastic or fabric sachets containing pre-measured doses for washing
machine usage.
[0045] The invention is illustrated by the following Examples in which parts and percentages
are by weight except where otherwise indicated. The terms Calgon, Bauknecht and Tergotometer
referred to in these examples are Trade Marks.
Example 1
[0046] Two detergent compositions were prepared to the following formulations:
[0047] Fabric washing trials were then conducted using the products A and B as prewash and
main wash products respectively, in a Bauknecht automatic washing machine. Water of
hardness 23°(GH) was employed with the recommended dosage levels of 150 g of powder
in both the pre- and main-washes. The same clothes were washed 15 times (boil wash)
after which low levels of inorganic deposits were found on the fabrics as follows:
Example 2
[0048] Experiments were carried out in a Tergotometer to demonstrate the effect of polyphosphates
on fabric incrustation. A detergent composition having the following formulation was
made up by mixing solutions.
[0049] Fabrics were washed using this composition to which orthophosphate, polymer phosphate
(Calgon 322) and polyacrylate were added as set out below. The wash conditions were
40°FH wash water hardness (Ca:Mg 4:1), 30
0FH flood and hand rinse water hardness (Ca:Mg 4:1), wash temperature 90°C, wash time
20 minutes, flood 2 minutes, rinse 5 minutes and product dosage 14 g per litre. The
results were achieved as set out in the following table.
[0050] It is clear from the above table that the delayed addition of polymerphosphate lowers
the level of fabric incrustation, particularly in the presence of polyacrylate.
1. A process for washing fabrics, comprising the steps of:
(i) contacting the fabrics with a wash liquor containing a synthetic detergent active
compounds and an alkali-metal or ammonium orthophosphate; and
(ii) subsequently contacting the fabrics with a wash liquor containing a synthetic
detergent active compound and an alkalimetal or ammonium polymer phosphate, each of
said wash liquors having a pH between 8 and 12, and each of said wash liquors containing
substantially no other phosphate detergency builders,
characterised in that step (ii) is carried out at least 15 seconds after step (i).
2. A process according to Claim 1, characterised by being carried out in two stages,
the fabrics being substantially separated from the wash liquor used in step (i) before
contacted with the wash liquor in step (ii).
3. A process according to Claim 1, characterised in that the wash liquor used in step
(i) remains in contact with the fabrics during step (ii).
4. A process according to Claim 1, characterised in that said alkalimetal of ammonium
polymer phosphate is present in the wash liquor used in step (i) in an undissolved
form.
5. A detergent composition for washing fabrics by a method according to Claim 1, comprising
a synthetic detergent active compound, an alkalimetal or ammonium orthophosphate and
an alkalimetal or ammonium polymerphosphate, said composition yielding a pH of between
9 and 11 when dissolved in 12°H (Ca) (French permanent hardness, calcium only) water
at 50°C and at a concentration of 0.1 % w/v and said composition containing not more
than 5% by weight alkalimetal pyrophosphate by weight of the composition and substantially
no other phosphate detergency builders, characterised by means for delaying the solubility
of said alkalimetal or ammonium polymer phosphate when the composition is added to
water to form a wash liquor.
6. A detergent composition according to Claim 5, characterised by a first container
containing at least a part of said synthetic detergent active compound and said orthophosphate
and a second container containing said polymer phosphate and optionally a further
part of said synthetic detergent active compound.
7. A detergent composition according to Claim 6, characterised in that said first
container and said second container are constituted respectively by a first compartment
and a second compartment of a sachet, said sachet being so constituted that when added
to water the contents of said first compartment are released before the contents of
said second compartment.
8. A detergent composition according to Claim 5, characterised in that said means
for delaying the solubility of said alkalimetal or ammonium polymer phosphate is constituted
by a slowly dissolving material with which said polymer phosphate is granulated or
encapsulated.
9. A detergent composition according to Claim 5, characterised by containing by weight:
from 2.5% to 50% of one or more synthetic detergent active compounds selected from
anionic, nonionic, amphoteric and zwitterionic synthetic detergent compounds:
from 2% to 20% of said alkalimetal or ammonium orthophosphate;
from 2% to 20% of said alkalimetal or ammonium polymer phosphate in such a form as
to delay its solubility when the composition is added to water to form a wash liquor,
the ratio by weight of said orthophosphate to said polymerphosphate being from 3:1
to 1:3;
optionally not more than 20% non-phosphate detergency builders or sequestrant builders;
optionally not more than 25% soap; and
optionally one or more ingredients selected from lather boosters, antiredeposition
agents, oxygen- releasing bleaching agents, per-acid bleach precursors, chlorine-releasing
bleaching agents, fabric softening agents, inorganic salts, fluorescent agents, perfumes,
enzymes, germicides and colourants.
1. Verfahren zum Waschen von Textilien, umfassend die Stufen des
(i) Zusammenbringens der Textilien mit einer Waschflüssigkeit, die eine synthetische,
waschaktive Verbindung und ein Alkalimetall- oder Ammoniumorthophosphat enthält, und
(ii) anschließenden Zusammenbringens der Textilien mit einer Waschflüssigkeit, die
eine synthetische, waschaktive Verbindung und ein Alkalimetall- oder Ammoniumpolymerphosphat
enthält, wobei jede der Waschflüssigkeiten einen pH zwischen 8 und 12 hat und jede
der Waschflüssigkeiten praktisch keine anderen Phosphat-Washmittelbuilder enthält,
dadurch gekennzeichnet, daß Stufe (ii) wenigstens 15 s nach Stufe (i) durchgeführt
wird.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß es in zwei Stufen durchgeführt
wird, wobei die Textilien von der in Stufe (i) verwendeten Waschflüssigkeit im wesentlichen
abgetrennt werden, bevor sie mit der in Stufe (ii) verwendeten Flüssigkeit zusammengebracht
werden.
3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die in Stufe (i) verwendete
Waschflüssigkeit mit den Textilien währen der Stufe (ii) in Kontakt bleibt.
4. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Alkalimetall- oder Ammoniumpolymerphosphat
in der in Stufe (i) verwendeten Waschflüssigkeit in einer ungelösten Form vorhanden
ist.
5. Waschmittel zum Waschen von Textilien nach einem Verfahren gemäß Anspruch 1, das
eine synthetische, waschaktive Verbindung, ein Alkalimetall- oder Ammoniumorthophosphat
und ein Alkalimetall- oder Ammoniumpolymerphosphat enthält, wobei das Mittel einen
pH zwischen 9 und 11 1 ergibt, wenn in 12°H (Ca) (französische Permanenthärte, nur
Calcium) bei 50°C und bei einer Konzentration von 0,1 Gew./Vol..-% gelöst, und wobei
das Mittel nicht mehr als 5 Gew.-% Alkalimetallpyrophosphat, bezogen auf das Gewicht
des Mittels, und praktisch keine anderen Phosphat-Waschmittellbuilder enthält, gekennzeichnet
durch Mittel zum Verzögern der Löslichkeit des Alkalimetall- oder Ammoniumpolymerphosphats,
wenn das Mittel Wasser zur Bildung einer Waschflüssigkeit zugesetzt ist.
6. Waschmittel nach Anspruch 5, gekennzeichnet durch einen ersten Behälter, der wenigstens
einen Teil der synthetischen, waschaktiven Verbindung und des Orthophosphats enthält,
und einen zweiten Behälter, der das polymere Phosphat und gegebenenfalls einen weiteren
Teil der synthetischen, waschaktiven Verbindung enthält.
7. Waschmittel nach Anspruch 6, dadurch gekennzeichnet, daß der erste Behälter und
der zweite Behälter jeweils durch eine erste Kammer und eine zweite Kammer eines Beutels
gebildet sind, wobei der Beutel so aufgebaut ist, daß, wenn er in Wasser gegeben wird,
die Inhalte der ersten Kammer vor den Inhalten der zweiten Kammer freigegeben werden.
8. Waschmittel nach Anspruch 5, dadurch gekennzeichnet, daß das Mittel zum Verzögern
der Löslichkeit des Alkalimetall oder Ammoniumpolymerphosphats aus einem sich langsam
lösenden Material besteht, mit dem das polymere Phosphat granuliert oder eingekapselt
ist.
9. Waschmittel nach Anspruch 5, gekennzeichnet durch folgende Gewichtsgehalte:
2,5 bis 5096 einer oder mehrerer synthetischer waschaktiver Verbindung(en), ausgewählt
unter anionischen, nitchtionischen, amphoteren und zwitterionischen synthetischen
Waschmittelverbindungen;
2 bis 20% des Alkalimetall- oder Ammoniumorthophosphats;
2 bis 20% des Alkalimetall- oder Ammoniumpolymerphosphats in einer solchen Form, daß
seine Löslichkeit verzögert ist, wenn das Mittel zur Bildung einer Waschflüssigkeit
Wasser zugesetzt wird, wobei das Gewichtsverhältnis des Orthophosphats zum Polymerphosphat
3:1 bis 1:3 ist;
gegebenenfalls nicht mehr als 20% Nicht-Phosphat-Waschmittelbuilder oder sequestrierender
Builder;
gegebenenfalls nicht mehr als 25% Seife und
gegebenenfalls ein oder mehrere Bestandteile, ausgewählt unter Schaumverstärkern,
der Widerabscheidung entgegenwirkenden Mitteln, Sauerstoff freisetzenden Mitteln,
Persäure-Bleichvorstufen, Chlor freisetzenden Bleichmitteln, Textil-weichmachenden
Mitteln, anorganischen Salzen, fluoreszierenden Mitteln, Parfums, Enzymen, keimtötenden
Mitteln und färbenden Mitteln.
1. Un procédé pour le lavage des tissus comprenant les étapes de:
(i) Mise en contact des tissus avec une solution de lavage contenant un composé synthétique
détergent actif et un ortho-phosphate de métal alcalin ou d'ammonium; et
(II) Dans la suite, mise en contact des tissus avec une solution de lavage contenant
un composé synthétique détergent actif et un polymère phosphate de métal alcalin ou
d'ammonium, chacune des dites solutions de lavage ayant un pH compris entre 8 et 12
et chacune des dites solutions de lavage ne contenant pas substantiellement d'autres
additifs de détergence phosphatés, caractérisé en ce que l'étape (ii) est affectuée
au point 15 secondes après l'étape (i).
2. Un procédé selon la revendication 1, caractérisé en ce qu'il est effectué en deux
étapes, les tissus étant séparés substantiellement de la solution de lavage utilisée
dans l'étape (i) avant d'être mis en contact avec la solution de lavage utilisée dans
l'étape (ii).
3. Un procédé selon la revendication 1, caractérisé en ce que la solution de lavage
utilisée dans l'étape (i) reste en contact avec les tissus pendant l'étape (ii).
4. Un procédé selon la revendication 1, caractérisé en ce que le dit polymère phosphate
de métal alcalin ou d'ammonium est présent dans la solution de lavage utilisée dans
l'étape (i) sous une forme non dissoute.
5. Une composition détergente pour le lavage des tissus par une méthode selon la revendication
1, comprenant un composé synthétique détergent actif, un orthophosphate de métal alcalin
ou d'ammonium et un polymère phosphate de métal alcalin ou d'ammonium, la dite composition
donnant un pH compris entre 9 et 12 lorsqu'elle est dissoute dans de l'eau 12°H (Ca)
(Dureté française permanente, calcium seulement) à 50°C et à une concentration de
0,1% en poids volumique et la dite composition ne contenant pas plus de 5% de poids
de pyrophosphate de métal alcalin en poids de la composition et ne contenant pas substantiellement
d'autres additifs de détergence phosphaté, caractérisée par des moyens pour retarder
la solubilité du dit polymère phosphate de métal alcalin ou d'ammonium quand la composition
est ajoutée à de l'eau pour former une solution de lavage.
6. Une composition détergente selon la revendication 5, caractérisée en un premier
récipient contenant au moins une partie du dit composé synthétique détergent actif
et ledit orthophosphate et un second récipient contenant le dit polymère phosphate
et facultativement une part supplémentaire du dit composé synthétique détergent actif.
7. Une composition détergente selon la revendication 6, caractérisée en ce que le
dit premier récipient et le dit second récipient sont respectivement constitués par
un premier compartiment et un second compartiment d'un sachet, le dit sachet étant
constitué d'une telle façon que, lorsqu'on l'ajoute à de l'eau, le contenu du dit
premier compartiment est libéré avant le contenu du dit second compartiment.
8. Une composition détergente selon la revendication 5, caractérisée en ce que les
dits moyens pour retarder la solubilité du dit polymère phosphate de métal alcalin
ou d'ammonium sont constitués par un matériau à dissolution lente avec lequel le dit
polymère phosphate est granulé ou encapsulé.
9. Une composition détergente selon la revendication 5, caractérisée en ce qu'elle
contient en poids:
de 2,5% à 50% d'un ou plus composés synthétiques détergents tensio-actifs choisis
parmi les composés synthétiques détergents tensio-actifs anioniques, nonioniques,
amphotériques, et zwitterioniques;
de 2% à 20% du dit orthophosphate de métal alcalin ou d'ammonium;
de 2% à 20% du dit polymère phosphate de métal alcalin ou d'ammonium sous une forme
telle que sa solubilité est retardée quand la composition est ajoutée à de l'eau pour
former une solution de lavage, le rapport du poids du dit orthophosphate au dit polymère
phosphate étant compris entre 3/1 et 1/3;
facultativement pas plus de 20% d'agents complexants de détergence non-phosphate ou
d'agents séquestrants; facultativement pas plus de 25% de savon; et
facultativement un ou plusieurs adjuvants choisis parmi des activateurs de mousse,
des agents antiredéposition, des agents de blanchiment libérant de l'oxygène, des
activateurs de blanchiment per-acides, des agents de blanchiment libérant du chlore,
des agents adoucissants textiles, des sels inorganiques, des agents fluorescents,
des parfums, des enzymes, de germicides et des colorants.