STORAGE-STABILIZED WASHING AGENT WITH BOOSTED BLEACH ACTION

AGENT DE LAVAGE A ACTION BLANCHISSANTE SURACTIVEE STABILISE EN STOCKAGE

English Abstract

Storage-stabilized washing agent with
boosted bleach action
Abstract of the disclosure:
The invention relates to storage-stabilized washing
agents with a boosted bleach action, containing 2 to
20% by weight of detergents and conventional washing
auxiliaries, including fillers, the washing agent con-
taining 10 to 50% by weight of a crystalline layered
silicate as a builder and a bleach, the quantity of
bleach being such that 0.5 to 4% by weight of washing-
active oxygen (AVOX) is present in the washing agent.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A storage-stabilized washing agent with a boosted bleach
action, with 2 to 20% by weight of detergents and conventional
washing auxiliaries, including fillers, containing 10 to 50% by
weight of a crystalline layered silicate as the builder and a
bleach, the quantity of bleach being such that 0.5 to 4% by weight
of washing-active oxygen (AVOX) is present in the washing agent.
2. The storage-stabilized washing agent as claimed in claim
1, containing 20 to 35% by weight of a crystalline layered sili-
cate as the builder.
3. The storage-stabilized washing agent as claimed in claim
1, wherein the bleach quantity is such that 1.0 to 2.5% by weight
of washing-active oxygen (AVOX) is present in the washing agent.
4. The storage-stabilized washing agent as claimed in claim
1, wherein the crystalline layered silicate is of the general
formula
NaMSi2O5
where M = Na or H.

11
5. The storage-stabilized washing agent as claimed in
claim 1, wherein the crystalline layered silicate
corresponds to the .delta. -modification of Na2Si2O5.
6. The storage stabilized washing agent as claimed in
claim 1, wherein the crystalline layered silicate
has a particle diameter from 0.01 to 1,000µ m.
7. The storage-stabilized washing agent as claimed in
claim 1, wherein the crystalline layered silicate
has a particle diameter from 1 to 20µ m.
8. The storage-stabilized washing agent as claimed in
claim 1, wherein the crystalline layered silicate
has an ion exchange capacity from 400 to
1,200 mmol of Na+/100 g of dry matter.
9. The storage-stabilized washing agent as claimed in
claim 1, containing inorganic phosphates, organic
phosphates, borates, citrates, gluconates,
nitrilotriacetic acid (NTA), iminodiacetates or
mixtures thereof as additional builders in
quantities of up to 20% by weight.
10. The storage-stabilized washing agent as claimed in
claim 1, composed of agglomerate particles having
a particle size in the range from 0.25 to 2.5 mm

12
and obtained by means of a spray-mist mixing pro-
cess.
11. The storage-stabilized washing agent as claimed in
claim 1, wherein the bleach is sodium perborate
tetrahydrate, sodium perborate monohydrate, sodium
percarbonate or mixtures thereof.

Description

~32~
~o~ 881~b~
The present invention relates to a storage-stabilized
washing agent with a boosted bleach action, in
particular a domestic washing agent for heavy laundry,
white laundry and colored laundry~ contalning 2 to 20~
by weight of detergents and conventional washing
auxiliaries, including fillers, as is used in washing
machines.
Due to the increasingly wide use of domestic washing
machines, the washing agent must be adapted to the
changed washing conditions.
15 .
Modern washing agent3 are therefore composed of a com-
bination of detergents as the washing-active sub-
stances, bleaches and additives which boost the washing
power, the so-called builders which, on the one hand,
eliminate the hardnes~ of the washing liquor and, on
the other hand, prevent depositions of inorganic salts
on the material being washed and thereby ensure a ~soft
handle" of the washed material after the washing
process.
Polymeric phosphate~, in particular sodium tripolyphos-
phate, are regarded as excellent builders. Because of
the danger of eutrophication of rivers and lak2s by the

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phosphate content in domestic effluents, the use of
zeolites a~ a builder has been proposed.
It has been found that the use of zeolites as a builder
ha~ the disadvantages that the washed material lo~es
the desired "soft handle" in tha course of a plurality
of washing steps. A further point is that, during the
storage tLme between the production and the consu~ption
of the washing agent, the washing agent lose~ part of
its washing power by decomposition of the bleach.
It has therefore been proposed in US-A-4,728,443 to add
to the washing agent an additional 1 to 20% by weight
of a crystalline layered ~ilicate or alkali metal ~
cate. In this way, it was possible to achieve a "soft
handle" of the washed material even if zeolites were
used as the builders; however, the ~torage stability of
the washing agent was not affected thereby.
It is the ob~ect of the invention to provide a washing
agent which has an improved storage stability and a
boosted bleach action, and maintains the ~'~oft handlel'
in the washed material.
Surpri3ingly, it has baen found that a storage-
stabilized washing agent with a boosted bleach action
is obtained when it contains 10 to 50% by weight, in
particular 20 to 35% by weight, of a crystalline

_ 3 _ 1 3 2 ~
layered silicate as the builder and a bleach, the
quantity of bleach being such that 0.5 to 4% by weight,
in particular 1.0 to 2.5% by weight, of washing-active
oxygen (AVOX) is present in the washing agent.
A crystalline layered silicate of the general formula
NaMsi2os
where M = Na or H,
has proved particularly suitable.
Very particularly good result~ are obtained when the
crystalline layered silicate corre~ponds to the ~-modi-
fication of Na2Si2O5.
Further preferred and selective features of the washing
~ agent according to the invention can be that
1 a) the crystalline layered ~ilicate haq a particle
; diameter from 0.01 to 1,000 ~m, in particular from
1 to 20 ~m,
b) the crystalline layered ~ilicate ha~ an ion
exchange capacity from 400 to 1,200 mmol of
Na+/100 g of dry matter,
c) the bleach is sodium perborate tetrahydrate,
sodium perborate monohydrate and/or sodium percar
bonate,

~L 3 2 ~ 3
d) it contains inorganic and/or organic phosphates,
borates-, citrates, gluconates~ nitrilotriacetic
acid (NTA) and/or iminodiacetates a addi~ional
builders in quantities of up to 20% by weight,
e) it is composed of agglomerate particles having a
particle size in the range from 0.25 to 2.5 mm and
was obtained by a spray-mist mixing proce s,
f~ it contain~, as the detergent, alkali matal salts
of alkylbenzene~ulfonates, higher alkylsulfonates
and/or higher fatty alcohol polyethoxylate-~ul-
fate~, in particular with alkyl radicals having 10
to 18 carbon atoms on average in the alkyl group,
and
g) it contains carboxymethylcellulose, carboxymethyl
starch and~or methylcellulo~e in quantities of up
to 10~ by weight as a washing auxiliary.
,
The crystalline layered cilicates used in the
production of the washing agent according to the
invention can be prepared according to US-A-4,664,839.
Even though all the crystalline layered silicates
listed in US-A-4,664,839 can bs employed in the washing
agent according to the invention, it ha~ been found
that ~-Na2Si2O5 is to ba preferred if a boosted bleach

- 5 _ 1 ~ 2 ~ u ~ ~
action during the washing process is important.
The washing-active oxygen (AVOX) of the bleach and of
the washing agent was determined in accordance with the
instructions by Dr. E. Heinerth, Tenside 2 (1965) 180.
The sodium perborate tetrahydrate (NaB03 x 4H20)
investigated had an AVOX number of 10% by weight;
sodium perborate monohydrate (NaB03 x H20) had an AVOX
number of 15% by weight and odium percarbonate
(2Na2CO3 x 3H202) had an AVOX number of 13.5% by
weight.
The washing power (bleach action) of the washing agent
was determined as the whiteness of the test fabrics
(WFR polye~ter/cotton ~oiled by tea, order code 20 G)
according to DIN 44983.
The washing power (bleach action) of the washing liquor
was determined by the difference method which follow~
from equation I
' ~ WR = % WGg - ~ WGb
where: % W~ = ~ washing power (bleach action)
% WGg = ~ whiteness of the washing material
% WGb = % whiteness of the unwashed material.
The storage te~ts wsre carried out under the following
forced te~t conditions:
Ths wa~hing agent to be investigated was stored in a

- 6 - ~32~
condition cabinet at a relative atmospheric humidity of
70% at a temperature of 37C. During the test, the
washing agent was packed in a waxed carton. The water
vapor permeability of the pac~aging wa 0.4 g~m2 x h.
The tested washing agent formulations are listed in
Table 1.
The degradation values of the bleach as a function of
the time after the forced storage test conditions are
compiled in Table 2. In addition, 2 commercially avail-
able washing agents based on zeolite and sodium tri-
polyphosphate were included in Table 2. The degradation
of bleach, in particular that of sodium percarbonate,
is very high in the preqence of zeolite.
Washing results:
The washing agent formulations 2 and 4 were tested in
accordance with DIN 44983 and calculated acccrding to
equation I. The washing power (bleach action) of
washing agsnt 2 was 30.0%, and that of washing agent 4
according to the invention was 36.5%.
The asse~sment of handle by a panel of experts gave a
markedly "softer handlel~ of the washed material, which
had besn washed with the washing agent 4 according to
the invention, as compared with the washed material
which had baen washed with the zeolite-containing

_ 7 _
washing agent 2.

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