[0001] The invention relates to liquid laundry detergent compositions containing optical
brighteners.
[0002] The use of optical brighteners in laundry detergent compositions has been known for
a long time. In liquid compositions in general, optical brighteners with poor water
solubility are used as dispersions because such products should have enough substantivity,
which means that their affinity to the fibres of the substrate that is to be washed,
should be high enough in order not to be washed out immediately. The use of such products,
however, has the disadvantage that the detergent compositions have a poor storage
stability, that is to say that the optical brightener will precipitate. If, on the
other hand, optical brighteners were to be used which are more soluble in water, these
products would have an insufficient substantivity to the fibres of the substrate to
be washed.
[0003] It has been found that when using optical brighteners of a specific chemical structure
which are water soluble, laundry detergent compositions with sufficient storage stability
can be obtained.
[0004] Similar optical brighteners have been used in liquid detergent compositions as described
in US Patent 4,233,167 and in European patent published application no. 106407. The
problem to solve in these known detergent compositions was to find optical brighteners
which would not counteract the effect of cationic softeners and would not provoke
these softeners to be deposited on fabrics as a yellow film (USP 4,233,167) or optical
brighteners which would not form insoluble complexes with the cationic surfactants
contained in detergent compositions. The preferred compounds mentioned in these patent
specifications do not have the desired substantivity.
[0005] The invention provides a liquid laundry detergent composition containing one or more
optical brighteners of formula I

in alkali salt or alkyl-, hydroxyalkyl-, or ammonium salt form,
in which both groups R, independently, are hydrogen, halogen, C₁₋₂ alkyl, C₁₋₂ alkoxy,
hydroxy or sulfonic acid groups,
each alkylene, independently, is an alkylene group with 2 or 3 carbon atoms,
each X, independently, is halogen, cyano, carboxamido, C₁₋₂ alkoxy or hydroxy,
and R1 is hydrogen or Alkylene -X, with the proviso that if X = hydroxy, R should
not be a sulfonic acid group in the para-position,
or containing optical brighteners of formula II

in which R is as defined above,
both alkyl groups, independently, have 1 or 2 carbon atoms, and both groups M are
hydroxyalkylammonium cations.
[0006] Preferably, in formula I and II, both groups R are the same and both groups X are
the same and the alkyl and alkylene groups have the same number of carbon atoms i.e.
compounds of formulae I and II are preferably symmetrical. More preferably, in compounds
of formula 1, X is other than hydroxy or R₁ is hydrogen. Especially preferred compounds
have the structure of formulae III, IV, V, VI and/or VII. Most preferred compound
is the one of formula III.

[0007] The optical brighteners according to the invention are used in powder form or as
solutions in water. Such solutions have a content of 18 to 75% by weight of active
substance and preferably also contain hydrotropic substances. The active substances
are well known and can be produced according to conventional processes.
[0008] Besides optical brighteners, the liquid laundry detergent compositions according
to the invention contain the usual components of such compositions. In general, such
components include anionic as well as non-ionic surfactants, builders, alkali, hydrotropic
agents, buffers, enzymes and the like will be contained. It is also possible to include
cationic softeners which will not precipitate.
[0009] The amounts of the components of such liquid laundry detergent composition are in
the usual ranges. Typical detergent compositions contain from 0.05 to 0.15% by weight
of optical brighteners (as 100% active substance), from 5 to 30%, preferably from
10 to 25% by weight of fatty acids, from 2 to 20%, preferably from 5 to 15% by weight
of a further anionic surfactant, from 0.5 to 12%, preferably from 1.5 to 8% by weight
of a non-ionic surfactant, to give in total from 20 to 50%, preferably from 30 to
50% by weight of surfactants and from 5 to 15% by weight of builders. The amount of
alkali should be sufficient to neutralize all acids present and to reach a pH value
suitable for washing.
[0010] The fatty acids which are used as anionic surfactants are preferably saturated and
unsaturated C₅₋₂₂ carboxylic acids, more preferably C₁₂₋₁₈. The fatty acids, for example
coco fatty acid or oleic acid are added as such and converted to the salt form by
addition of alkali e.g. NaOH, KOH or an organic base e.g. triethanolamine.
[0011] Further anionic surfactants which can be present may be any of the following conventional
types:
a) sulphates and sulphonates of fatty acids, fatty acid esters and fatty acid amides
b) linear or branched C₅₋₁₈ alkyl sulphates and sulphonates
c) sulphated ethoxylated compounds, particularly sulphated forms of any non-ionic
surfactants which may be present
d) polycarboxylic acid ester sulphates and
e) C₅₋₁₈ alkylbenzenesulphonates and C₁₋₄ alkyl and dialkylnaphthalene sulphonates.
[0012] These compounds may be added in acid form and converted to their salt forms by addition
of alkali.
[0013] A preferred class of surfactants which are only weakly anionic are of the formula
IX
R-O-(CH₂CH₂O

(A-COOH)
x IX
in which R is the residue of a C₈₋₂₂ fatty alcohol or of an alkylphenol having 10-24
C atoms;
A is a methylene or ethylene group;
m is a number from 1-20;
and x is an average value from 0.1 to 1.
[0014] Compounds of formula IX are known or may be prepared by conventional methods from
available starting materials. The most preferred component (B) is a compound of formula
IX obtained by reacting a synthetic lauryl alcohol (C₁₂₋₁₅) with 4-5 moles ethylene
oxide and subsequently with 0.8 mole chloracetic acid. The compounds are normally
used in the form of their alkali metal salts, particularly sodium salts.
[0015] Nonionic surfactants which may be present include ethylene oxide (EO) / propylene
oxide (PO) block copolymers (Pluronics), and the addition products of EO or PO, preferably
EO, to fatty alcohols, fatty amines, fatty acids, fatty acid alkanolamides and alkylphenols.
Such non-ionic surfactants are conventional and commercially available.
[0016] Hydrotropic compounds which may be present include for example urea, dicyandiamide
and its derivatives, alcohols, water-soluble glycols, glycol ethers and glycol esters
and C₁₋₄ alkylbenzenesulphonates, provided that the compounds display no cloud point
in distilled water up to 100°. They act so as to prevent phase separation, that is
to stabilize the liquid composition.
[0017] Sequestering agents include citric acid, nitrilotriacetic acid and other complex
formers. Buffers may be used to stabilise the pH of the wash liquor in the neutral
or alkali region. Buffer substances include sodium bicarbonate, sodium carbonate and
sodium silicate.
[0018] Further optional components include cationic softeners, e.g., products of acylation
and quaternization of a polyalkylene polyamine of the formula X

in which each R₁, independently, is C₁₂₋₁₈ alkyl or C₁₂₋₁₈ alkenyl;
each n, independently, is 2 or 3;
R₂ is C₁₋₄ alkyl, C₁₋₄ hydroxyalkyl, or C₁₋₄ hydroxyalkyl etherified with 1-10 ethylene
oxide groups;
R₃ is C₁₋₄ alkyl or benzyl;
and X
⊖ is a halide, methylsulphate or ethylsulphate anion.
[0019] By selection of these additional components the washing effect of the liquid detergent
can be adjusted for the desired field of use. The liquid detergent compositions of
the invention are primarily useful as domestic laundry detergents. Not only do they
display good washing power, they also produce a soft handle on laundered cotton goods.
Being phosphate-free, they are ecologically acceptable. The liquid compositions of
the invention are stable and do not separate into two phases, nor do the optical brighteners
crystallize and precipitate on storage.
[0020] In the following examples 1 to 7 (table), the carboxymethylated ethylene oxide adduct
of the formula
C₁₂₋₁₅O(CH₂CH₂O)
4,5 - (CH₂COONa)
0,7
as a 50% paste in water, the non-ionic surfactant of the formula

as a 99% paste in water, the softener of the formula

in which R
x = 85% oleic acid and 15% stearic acid residue, as a 90% solution in water, polyacrylic
acid A with MW 100.00 as a solution of 29% of the semi-neutralized acid (sodium salt),
polyacrylic acid B with MW 4500 as a solution of 49% are used as well as the optical
brighteners with the given formulas in the following compositions:
Formula III as an aqueous solution that contains 28% active substance
or as a powder with 89% active substance
Formula IV as an aqueous solution that contains 20% active substance
Formula V as an aqueous solution that contains 23% active substance
or as a powder with 50% active substance
Formula VII as an aqueous solution that contains 34% active substance
Formula VI as an aqueous solution that contains 33% active substance.
[0021] Example 1 is a so-called fabric softener, Example 2 is a liquid laundry detergent
for industrial use, Example 3 is a complete laundry detergent for domestic use, Example
4 is a liquid laundry detergent with fabric softener for domestic use, Examples 5
and 6 are liquid laundry detergents for domestic use, and Example 7 is a concentrated
complete laundry detergent for domestic use.
Table
|
Percentage by weight |
Example |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
Component |
|
|
|
|
|
|
|
Demineralised water |
86.4 |
65.0 |
57.8 |
27.5 |
31.7 |
30.5 |
53.9 |
sodium xylenesulphonate |
- |
4.5 |
6.0 |
- |
- |
- |
6.5 |
isopropanol |
2.0 |
- |
- |
12.0 |
12.0 |
12.0 |
- |
ethylene glycol |
- |
3.0 |
- |
- |
- |
- |
- |
propylene glycol |
5.0 |
- |
- |
- |
- |
- |
- |
dodecylbenzene sulphonic acid |
- |
2.0 |
6.0 |
8.0 |
8.0 |
8.0 |
6.0 |
coco fatty acid |
- |
- |
6.0 |
15.0 |
8.0 |
12.0 |
6.0 |
oleic acid |
- |
2.0 |
- |
5.0 |
5.0 |
5.0 |
- |
Carboxymethylated ethylene oxide adduct |
- |
- |
- |
15.0 |
20.0 |
20.0 |
- |
non-ionic surfactant |
- |
- |
- |
- |
5.0 |
- |
- |
softener |
6.5 |
- |
- |
5.0 |
- |
- |
- |
sodium hydroxide |
- |
2.7 |
- |
- |
1.8 |
- |
- |
potassium hydroxide |
- |
- |
6.2 |
- |
- |
- |
5.1 |
diethanolamine |
- |
- |
- |
11.7 |
- |
8.0 |
- |
triethanolamine |
- |
- |
- |
- |
8.0 |
4.0 |
- |
sodium hydrogen carbonate |
- |
- |
2.5 |
- |
- |
- |
- |
sodium silicate (Na₂O:SiO₂)1:2 |
- |
10.0 |
- |
- |
- |
- |
4.5 |
sodium nitrilotriacetate |
- |
3.0 |
- |
- |
- |
- |
2.0 |
polyacrylic acid A |
- |
- |
15.0 |
- |
- |
- |
15.0 |
polyacrylic acid B |
- |
7.5 |
- |
- |
- |
- |
- |
brightener III liquid |
0.1 |
- |
- |
- |
- |
- |
- |
III powder |
- |
0.3 |
- |
- |
- |
- |
- |
IV liquid |
- |
- |
0.5 |
- |
- |
- |
- |
V liquid |
- |
- |
- |
0.8 |
- |
- |
- |
V powder |
- |
- |
- |
- |
0.5 |
- |
- |
VII liquid |
- |
- |
- |
- |
- |
0.5 |
- |
VI liquid |
- |
- |
- |
- |
- |
- |
1.0 |
|
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
100.0 |
pH of the solution |
5.5 |
13.3 |
9.5 |
7.5 |
7.5 |
7.5 |
12.5 |
1. A liquid laundry detergent composition containing one or more optical brighteners
of formula I

in alkali salt or alkyl-, hydroxyalkyl-, or ammonium salt form,
in which both groups R, independently, are hydrogen, halogen, C₁₋₂ alkyl, C₁₋₂ alkoxy,
hydroxy or sulfonic acid groups,
each alkylene, independently, is an alkylene group with 2 or 3 carbon atoms,
each X, independently, is halogen, cyano, carboxamido, C₁₋₂ alkoxy or hydroxy,
and R₁ is hydrogen or Alkylene -X, with the proviso that if X = hydroxy, R should
not be a sulfonic acid group in the para-position,
or containing optical brighteners of formula II

in which R is as defined above,
both alkyl groups, independently, have 1 or 2 carbon atoms, and both groups M are
hydroxyalkylammonium cations.
2. A liquid laundry detergent composition according to claim 1 in which the optical
brighteners are added in powder form or as solutions in water, also containing hydrotropic
substances.
3. A liquid laundry detergent composition according to any one of claims 1 and 2 containing
anionic as well as non-ionic surfactants, sequestering agents, alkoli, and optionally
buffers, enzymes and/or cationic softeners.
4. A liquid laundry detergent composition according to any one of claims 1 to 3 that
is phosphate free.
5. A liquid laundry detergent composition according to any one of claims 1 to 4 in
which the optical brightener is of formula III.
6. A liquid laundry detergent composition according to any one of claims 1 to 4 in
which the optical brightener is of formula IV.
7. A liquid laundry detergent composition according to any one of claims 1 to 4 in
which the optical brightener is of formula V.
8. A liquid laundry detergent composition according to any one of claims 1 to 4 in
which the optical brightener is of formula VI.
9. A liquid laundry detergent composition according to any one of claims 1 to 4 in
which the optical brightener is of formula VII.
10. A liquid laundry detergent composition as described in any one of the Examples.