Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
6~ ~
- ~ This invention refers to a group of silicic acid
compounds to be used in laundering and with the specific
property of depositing microamounts of silicic acid on
textile fibers during laundering, by which deposition
process the redeposition of soil from the laundry medium
to the textiles is prevented. Hence, the invention is of
special importance for laundering and the treatment of
polyester and cotton textiles which usually show a
decreasing brightness with repeated laundering due to
redeposition of soil from the laundry medium.
Thus, a basic object of the present invention
is to realize a detergent component which prevents soil
redeposition and progressive greying of polyester fibers
and textiles of such fibers.
;~ A further essential object of the present
invention is to provide a detergent component based on
, silicic acid which is usable at a pH of below 10.5 in large
concentrations and which functions as a builder and - -
;~ ~ , . . .
complexing agent such that the polyphosphate component can be
i~
reduced in the detergent composition.
It is well known that soluble alkali silicates
such as sodium metasilicate and waterglasses are used as
;' components in washing detergents. Some of their drawbacks
are a very high alkalinity and the risk of massive and
uncontrolled silica precipitation on textiles if pH
decreases which makes them hard, brittle and grey due to
preC\ ~ Q`+Id~ cl~QC~ .
the inclusion of~soil.
The present invention refers to a new group of
silicic acid complexes which does not form any dangerous
precipitate, even if pH decreases to 8, which is a very
low pH for detergent compositions. Within the pH range of
from 8 to 12 and preferably from 8 to 10.5 these new
compounds deposit a very small amount, a microamount, of
6~,
~silicic acid or silicic acid compounds Oll fibers such as
-polyester and cotton. This microamount is far from
dangerous to the textiles and cannct be measured as an
increased ash content, only qualitatively detected by
electron initiated x-ray emission in an electron microscope.
The degree of deposition is consequently very difficult to
estimate, but an increased ash content can be analyzed down
to 0.01% and because this deposition is even lower it may
be estimated to about 0.001% or 10 ppm of the fiber weight.
For the present discussion, this small amount o
silicic acid deposition will be called "microdeposition",
and the compounds responsible for this microdeposition
"microdepositors". This microdeposition is highly advantageous
with respect to the prevention o~ soil redeposition on textiles,
, ' r
~ because it induces a strong negative electrical charge to
.~; .
the fibers even when positive ions such as Ca , Mg +
; are present.
;
Microdepositing silicic acid compounds or
"microdepositors" are adduct (hydrogen bond) compounds of
oligomer and/or polymer silicic acid and ethylene oxide
products with a critical and limited amount of alkali
.
corresponding to a molar ratio SiO2:M20~ 4 or preferably 6-100,
in which formula M20 is Na20, K20, Li20 or the corresponding
"oxide" of quaternary ammonium compounds. It should be
~` emphasized that this small content of alkali is not sufficient
to give a water soluble silicate such as waterglass. The
highest commercia] ratio in produc-ts available on the market
is about SiO2:M20 = 3.5, and ratios above that limit mostly
give gels which are difficult to handle. For solubilities
of ratios above 4 specific silica structures are required
The ethylene oxide products used for production of
the adduct (hydrogen bond) silicic acid compounds can be the
simple polyethylene glycols, and preferably those with 10-100
.~ .
:~
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ethylene oxide units in the molecule. From the economic point
of view, it is advantageous to use polyethylene oxide products
which are of great value per se in laundering, for ins-tance the
nonionic tensides achieved by reacting nonyl phenols, fatty
alcohols, fatty amines (saturated and unsaturated) etc. with
ethylene oxide. For this special purpose tenside products with
~ up to 30 ethylene oxide units can be used and 10-20 units
,~ in the molecule are to be preferre,d, due to the solubility
properties of the silicic acid adduct.
The molar ratio of Si02:-C~2CH20- is not very
critical for the function of the product as "microdepositor"
of silicic acid but it is important for the efficient use
of the silicic component. The ratio SiO2:-CH2CH20- can be 1
and higher but preferably between 1.5 50. At the higher
ratios some silicic acid will remain as solid particles or
suspended particles in the laundry medium, but will not
precipitate or attach to the textile material in case the
silicic acid is of specific gel type, preferred here and
described below.
, It is known that hydrogen bond adducts ~complexes)
between soluble silicic acid (oligomers) and polyethylene
oxide products occur on the acidic side. Hence a solution
of acidic oligomer silicic acid gives a precipitation of a
hydrogen bond complex with soluble polyethylene oxide compounds.
The new interesting discovery is that these hydrogen bond
~ ~ complexes also form specific complexes on the alkaline side,
`~ which have remarkable solubility properties in spite of a low
alkali~content,~quite different from those of~ only-silicic
acid or only polyethylene oxide compound, especially in the pH
.~ , ,
~,, range of 8-10.5. Below pH 8 they precipitate as a homogeneous
,~ compound, which can be redissolved, if the pH is increased to 8.
Above pH 12 the compounds rapidly disintegrate to common soluble
silicates and polyethylene oxide compounds. Between pH 10.5
5i4
and 12, thi~ disintegration proceeds more slowly, for which
reason laundering can be perf`ormed up to a pH of 11.0 11.5
with some retained microdeposition of silicic acid on the
textile material.
The most important step in producing a silicic
depositor compound is the preparation of the silicic acid
component itself. Even if soluble silicates such as
waterglass are the raw materials for the desired silicic acid
component, it is hardly possible to synthetize the depositor
direct from soluble silicates, especially not when a dry detergent
is required by the market, The best way is to start from a
solid but active silicic acid polymer. Some precipitated
silica trade marks can be used as well as pyrogenic
silica (from silicium tetra chloride) but the final product
achieved is inferior compared with the product achieved
with a solid silica gel having a BET-surface of at least 200 m /gO
Such a solid silica gel can be polycondensated and
precipitated preferably in the presence of the polyethylene
oxide component from a solution of oligomer silicic acid
at a pH below 9 and preferably below 6 and even down to 2-4.
The BET-surface achieved on the silica gel
depends very much on the pH under the precipitation (and
polycondensation stage) which is indicated in the following
- table: -
pH BET-surface m /g
9 200
8 275
6 350
~25
3 500
~ 2 700
-`
The solid silicic acid component can be
polycondensa$ed and precipitated in the presence o~ the
polyethylene oxide compound or this can be added later
~or instance in connection with $he alkalization process.
.~
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Suitable steps of production are the following:
1. Waterglass is rapidly acidified on being poured in-
to sulphuric acid to ~orm soluble oligomer silicic acid.
2a. When the mixture has reached a pH of 2-3 the poly-
ethylene oxide component is added J which will cause the formation
of a second liquid phase which solidifies during the polyconden-
satlon process to a compound gel comprising polysilicic acid and
the polyethylene oxide compound. Polycondensation may be per-
formed in connection with spray-drying.
2b. The soluble oligomer silicic acid ca~ also be poly-
condensated alone without the polyethylene oxide component, but
it is then more necessary to increase the pH and the temperature
to increase the rate of polycondensation The solid gel has to
be broken up to a slurry and then the polyethylene oxide compon-
ent should be added.
2c. To the soluble oligomer silicic acid may also be
added a soluble Al-sulfate or other Al-salt in order to incorpor-
ate A1203 in the depositor product, which seems to increase its
efficiency. The ratio SiO2:A1203 should be above 2 and preferably
between 4 and 40. Also in this case the polyethylene oxide com-
ponent can be added before or after solidification.
3 The intermediate product can, if desired, be washed
free of the sodium sulfa$e formed, and it should be dried to a
water content of about 5-20%.
~` 4. The final step, the alkalization, can be performed
; by grinding the intermediate product with sodium hydro~ide, meta-
silicate or waterglass or any other strongly alkaline salt of weak
acids, e g. perborates and borates at the alkali ratio specified.
~ It is important that some moisture be present during this alkali-
`~ 30 zation step. The alkalization process can preferably be per~ormed
~` simultaneously with the final compounding of the dete:rgent compo-
sition utilizing the s-trong alkalinity of other composition ingre-
dients like perborate, borate and trisodiumphosphotate.
, ? ~
"~`: ' ~
The use of the speclfic silicic acid component ac-
cording to 1 and 2 above, offers the advantage that the silicic
acid component can be in surplus o~ the other compounds, without
precipitation and attaching the textile material, ~hen other
types of sillca (precipitated or pyrogenic) are used the sur-
plus of "unreacted" silica will directly attach to the textiles
and increase the ash content, With increasing BET-surface and
with the addition of Al-salts to the oligomer silicic acid, the
ion exchange capacity o~ the product increases from 90 to 120
mg CaO/G product which is important when hard waters are used
for laundering,
The invention is particularly directed toward a
silicic acid product to be used for laundry purposes with the
property of depositing microamounts of silicic acid on cellulose
~ and polyester ~ibers o-f laundry textiles and thereby preventing
; redepositioD of soil from the laundry medium on the textile
materials, The silicic acid product comprises an adduct
(Hydrogen bond) compound of oligomer and/or polymer silicic
acid with polyethylene oxide compounds together with alkali,
M2O, where M is selected from the group consisting of Na, K,
Li and quaternary ammonium radical, amounting to a molar ratio
SiO2:M2O~ 4, The product is physically or colloidally soluble
in a laundry medium inside a pH of 8-12, in which medium it
serves as a microdepositor for silicic acid on laundry textiles,
The iDVention is also directed toward a process for
manufacturing a silicic acid product comprising the steps,
per~ormed between 0-100C in the presence of water, of: pre-
- paring a solid silicic acid compound ~Gel) with a B~T-sur~ace
o~ more than 200 m2/g by polycondensation and/or precipitation
o~ a soluble (oligomer) silicic acid or alkali silicate by
.~ .
performing the polycondensation/precipitation at a pH below
9; reacting the resulting solid silicic acid compound with a
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polyethylene oxide product, after its solidiflcation or
during the polycondensation/precipltation process; and re-
acting the resulting adduct compound between silicic acid and !::
polyethylene oxide product with alkali, M20, in an amount
corresponding to a molar ratio SiO2/M20 of at least 4
Example I
A solid polyethylene glycol-, "Modopeg* 4000" with
high molecular weight was dissolved in water to a 15% solution
Standard waterglass available on the market containing about
10 360 g SiO2 per litre was diluted to twice the volume and 200 ml
of this mixture was batched, under intensive agitation and in
an extremely fine jet to 100 ml 4- normal sulphuric acid. Once
all of the waterglass had been consumed, the pH of the mixture
was determined at 1.4. To this mixture, which thus contained
about 36 g SiO2 in the form of acidic oligomer silicic acid
(solution) was added 100 ml of the above-disclosed Modopeg
solution which thus corresponds to 15 g of high molecular poly-
ethylene glycol.
./ Immediately `after the mixture, which was carried out
: `
~'`,5 20 at from 20 to 30C, the solution was clouded and a separate
~','f liquid phase which was heavier than the aqueous phase separated
out. After agitation for 3 h, the separated liquid phase as-
sumed a solid crystalline-like structure This was subjected
~. .
5;i. to wet milling, and after 4 h, the "crystals" were filtered
off, washed and dried. The filtrate was checked such that it
showed further clouding on the addition o~ more Modopeg solution,
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which showed that excess oligomer silicic acid was present,
The filtered-off deposit, dried at a tempexature
of at most 80C, weighed 46 g, which corresponds to a silicic
acid absorption of 31 g (slightly in excess of 1/2 mol)
of the batched 15 g Modopeg (1~3 equivalent weight of
ethylene oxide), This, like silica and carbon analysis,
showed that each ethylene oxide group had absorbed 1,56
mol silicic acid (SiO2), The dried powder was milled in
a mortar and rapidly mixed with 17 ml 10-normal NaOH
(slightly in excess of 1/6 mol), After 30 s the mixture
assumed a pasty consistency~ but hardened to a solid
crystalline substance within 3 minutes, This proved to be
of unrestricted storage life and was to 95% soluble in 60C
warm water, It is possible to obtain solutions with up
to 15% dry content, These have a pH of 11, whereas 1%
solutions display a pH of 9,6,
; In the acid addition to a 1% solution, ethoxy
silicate at pH 7-8 was deposited, The deposition appeared ;.
to be total at pH 3-5, The deposition is easily filtered
and easily dried, It gives a ratio C/Si which suggests
that each ethoxy group binds 1,43 SiO2 units. The product
; obtained was examined as a detergent component and it
proved that the product prevented greying simultaneously
as silicic acid was deposited,
~- Example 2
~ The same oligomer silicic acid as in Example 1
;~ was prepared anew and batched to a 10% solution of oc-tadecyl
;~ alcohol, reacted with 18 mol ethylene oxide, In this case
use was made of 200 ml of 10% tenside solution (20 g)
;3~ together with 300 ml acidic oligomer silicic acid, containing
120 g SiO2 per litre ~36 g), The deposition which was first
obtained was more waxy and assumed, after 2 h, a hard
crystalline character, After 4 h, it was filtered off
and washed. It was checked that -the filtrate contained
excess oligomer silicic acid. After drying, 48 g o-f
the product was obtained. This weight, together with
C/Si analysis, showed that each ethylene oxide group had
reacted with 1.44 mol silicic acid.
The product which contained slightly less than
1/2 mol SiO2, was alkalized with 15 ml 10-n NaO~. The
product thus obtained was soluble to from 96 to 97% in
warm water and it was possible to obtain a 12~o solution
thereof. In the 1~ solution, the pH was 9.1. On -the
addition of sulphuric acid to a 1% solution, the product
precipitated at pH 7.2. The deposition seemed to be
finely crystalline and could easily be filtered ~nd
washed. The thus-obtained secondary deposition had a
C/Si ratio corresponding to 1.56 Si02 per mol ethylene
oxide.
The product which was obtained directly after
the alkalization was used as a detergent component in a
detergent mixture of low phosphate content, This mixture
~O was used for washing polyester fabric 10 times. The
results were striking, inasmuch as the polyester -fibers did
not grey in comparison with the case when washed in a washing
; solution which contained a corresponding detergent
composition b~t wi-thout the ethoxy silicic acid adduct,
A scanning analysis with electron initiation of the
.
surface of the washed polyester fibers clearly showed a
deposition of silica on the samples which were washed
when the ethoxy silicic acid adduct was present.
Exam~e 3
~` A polysilicic acid was prepared. As starting
materials, use was made of a waterglass solution consisting
of equal par-ts of water and waterglass with a ratio SiO2:Na20
of 3,3~ 400 par-ts by volume of the waterglass solutlon
~ . '
were batched in the form of fine jets to 160 parts by
volume 2.5 molar sulphuric acid under intensive agitation,
The thus-obtained solution of oligomer silicic acid was
adjusted with NaOH to pH 2,5. This solution was then
mixed with 50 parts by volume of a non-ionactive tenside
which consi.sted of a 10% nonylphenol polyglycolether
:solution (16 E0). Air was then whisked into the tenside-
containing solution of oligomer silicic acid by means
of an extremely high-speed double agitator and the
temperature was raised to 60C, $he silicic acid polycondensing
to a solid gel. The -thus-obtained solid gel was dried in ~:
a drumdrier at 110C to a residual moisture content of
about 20% and was then subjec-ted to comminutio.n in a
: pinned disc mill to a particle size of from 1 to 1000 ~.
Example 4 -
The same procedure i.s here applied as in Example 3,
apart from that the solution of oligomer silicic acid, after
the addition of non-ionactive tenside, was not foamed by
~: whisking but instead introduced into a spray-dryer (Niro
Atomizer). In the treatment in the spray-dryer, the solution
of oligomer silicic acid was atomized and given highly
;~ voluminous form, The temperature in the air entering the
spray-dryer was about 320C and the temperature of the
. ~ exhaust air was about 130C. Because of the high temperature
prevailing in the spray-dryer, the silicic acid solution
, ~
gelled and a solid, polycondensed silicic acid in voluminous
~; pulverulent form was obtainedO The particle size of the
; thus-obtained polysilicic acid was within the order of
magnitude.of from 1 to 1000 ~ and no further comminution
was necessary.
Thus, the use of a spray dryer creates a simplified
process in which the realization of voluminous form,
polycondensation, drying and comminution take plac~e, as i$
were, in the same operation.
The acidic product achieved can be used directly as
additive to the detergent composition provlded that the required
alkali 1s supplied together with other ingredients like strongly
alkaline phosphates and perborates.
E~ample_5
In order to clarify the greying effects and ash contents
in the use of conventional detergents as compared with the case
involving detergents containing polysilicic acid with a large BET- `~
surface of more than 200 mZ/g washing experiments were carried out
with the help of a terg-0-Tometer (a laboratory washing machine
from the United States Testing Company Inc.). The greying of the
wash was determined by reflexion measurement (Elrepho) be~ore the
washing experiments and`after ten washes. The ash content of the
wash after the wash experiments were determined in accordance with
SIS 87 21 Ol.
The conditions in the washing experiments were as follows:
Temperature: 60C `
. Water hardness: 15dH
20 Dosage: 5 g/l
Time: 35 min
Speed: lO0 cycles/min
Amount o-f soili~g: 0.4 g/l air-filter dust and -i
l g/l synthetic skin grease
Number of washes: lO
Test fabrics: 100% cotton, bleached (WFK test fabric)
lG0% polyester tTerylene ~ , from ICI)
~; Polyester/cotton 65/35 ~"Hot-box',
commercial fabric~
30 Rinsing: under cold running water `
,~
Detergent: As the detergent base use was made of Test
Detergent A according to Swedish Standard
SIS 18 2410 with the following components:
- 10 -
~ ! ~
Z~
Detergent A: Dodecylbenzene sulphonate 100% 5%
Tallow fat alcohol, 50 EO5%
Soap, tallow type, 100% 4%
Pentasodium triphosphate (Na5P3010~ 30~O
~ Waterglass (Na2O.3~2SiO2.4H20) 5%
; Soda, calcined (Na2C03) 5%
Na-CMC, 100% 1%
Magnesium silicate (MgSiO3) 1%
- EDTA-Na4, 100% ` 0.2%
Sodium sulphate, calcined, 100%
Trisodium phosphate (Na3P04.12H20) 10%
I
~~ Sodium perborate (NaB03.4H20) 25%
. Water and salts from dodecylbenzene
sulphonate, soap, waterglass, Na-CMC
and EDTA-Na~ to 100%
Detergent B: as per detergent A, wherein 5% of
trisodium phosphate (Na3P04.12H2O) ~ -
were replaced by the product according
to the present invention manufactured
in Example 3.
, The results are accounted for 1n Table 1.
, TABLE 1
,,,: ' ,:
~;; Polyester/Cotton
~;100% Polyest~r 65/35 _ 100% Cotton
Greying, Greying, Greying,
units units units Ash-content
Detergent Ash-content Ash-content
greyer ~% greyer % greyer %
~; A 41 1.43 13 0.80 14 0.24
B 26 0.78 lQ 0.61 16 0.26
It is apparent from Table 1 that detergent B which
was based on the polysilicic acid according to the invention,
resulted in a marked reduction of the greying and ash-content
in the washing o-f polyester material. Also in the washin~g
of mixed ma-terial of polyester/cotton, a reduced greying
and ash-content were obtained, whereas the results in washing
~cotton material were comparable with those obtained by means
, ' .
. 11 ' ~'
of conventional detergent,
Example 6
A commercial washing powder known as VIA, part No,01311,
was tested in relation to a washing powder containing the acidic
compound according to Example 4 and with the -following composition:
The sillcic acid product
of ~x. 4: 5 %
Soda: 5 %
Sodium sulphate 32 %
Non-ionic tenside 8 %
10 Tallow soap ~ %
Magnesium silicate 0.5%
Sodium perborate 20 %
CMC o 5%
~ Sodium tripolyphosphate 25 %
," 100 %
The test procedure was as follows:
Temperature: 60C
Water hardness: 15C
"; Programme: normal coloureds
Dosage: 90 g per wash (15 1 of water)
. Soil loading: one cloth piece with 2.5 ml o-f used
engine oil
~ one cloth piece with 2.5 ml of coffee
:~. one cloth piece with 2.5 ml o~ tea
one cloth piece with 1 g of mustard,
1 g of ketchup, 08.2 g of synthetic
skin grease and 0.18 g or air filter
dust
Weight loading: 2 kg of towels
Test fabrics: 100% polyester, gabardine with 65/35%
polyester/cotton from EMPA (Eidgen-
~ssische Materialpr~fungs- und Versuch-
sanstalt)
i~ - 12 -
Results after 10 washing cycles are illustrated in
Table 2:
TABLE 2
Polyester 100% Polyester/Cotton 65/35
Products Greyingl) Ash Content2) Greyingl) Ash Content2)
Commercial
washing powder 44 1.51% 10 0.55%
Washing powder
with product ac-
cording to Ex. 4 22 0.62% 6 0045%
__ _ . _
;
1) Greying is specified in units o~ greyness above the
initial value and determined by means o~ reflection
~ measurement (Elrepho),
.~ 2) As per Swedish S-tandard SIS 872101.
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xample 7
In order to establish the washing e~fect with
respect to greying and ash-content in -the washing o~ soiled
textiles using conven-tional detergent and detergent containing
polysilicic acid according to the present invention t washing
experiments were carried out in a normal domestic washing
machine, Greying and ash-content were determined in the
manner disclosed in Example 5. The experiment conditions
.. were as ~ollows:
Temperature: 60C
.~ Water hardness: 15dH
~; Dosage: 100 g/wash = 15 litres o~ water :
:. Rinsing: 4 times with 30 litres of water/time
Amount of soiling: 2 cloth pieces 20 x 40 cm were soiled
in the washing machine at 90C with
3 g Flammouss ~carbon black) and 0.6 g
black iron oxide.
.' 1 cloth piece smeared with 2.5 ml used
,~: ` motor oil
~,o 1 cloth piece smeared with 2.5 ml coffee
. 1 cloth piece smeared with 2.5 ml tea
1 cloth piece smeared with 1 g mustard,
; 1 g ketchup as well as 1 g synthetic skin
grease and air-filter dust in the ratio 9:2.
Number of washes: 10
Test fabrics: 100% cotton, bleached (Testfabric
International)
100% polyester (Terylenè ~ from ICI~
Polyester/cotton 65/35 ("Hot-box",
; 30 commercial fabric).
Detergent: As detergent base 9 use was made of Test
Detergent A according to Swedish Standard
SIS 18 24 10 as described in Example 4,
Detergent A: Test detergent A
14
Detergent E: as per detergent A, wherein 5% of the tri-
sodium phosphate (Na3P04.12H20) were re-
placed by the product according to the pre-
sent invention.
The results are accounted for in Table 3:
TAB~E 3
, . .
100% Polyester Polyester/Cotton 100% Cotton ;.
65/35
-~Greying, Ash- Greying, Ash- Greying, Ash-
Detergent units content units content units con-tent
10 greyer % greyer %greyer % ~ -
A22 1.09 5.4 0~782.7 0,42
E5 0069 5.1 0.802.9 0.48
~ ' --
; It is apparent ~rom Table 3 tha-t the detergent which con-
tained polysilicic acid according to the present invention gave
; an extremely marked reduction in greying and ash-content as com-
pared with the conventional detergent in the washing of polyester
:-
material, whereas the result in the washing of mixed material of
; polyester/cotton and pure cotton was comparable with that obtained
with the conventional test detergent.
As was mentioned b-y way oE introduction, the polysilicic
acid according to the present invention cannot only be used as a
detergent component but also as sorption agents and carriers for
different subjects. Thus, the polysilicic acid according to the
present invention displays a considerable capacity as a drying
agent and as an absorbing agent/ion exchanger. It is of particu-
lar interest that this acid has an abnormally high absorption ca-
pacity for certain substances and in particular base substances.
It should finally be emphasized that silicic acid de-
positors according to this invention may comprise physically so-
luble ingredients and colloidally soluble ingredients which are
both efEicient from the silicic acid mlcrodepositlon poin-t of
view. The presence o-E sal~s such as sodium sulfa-te depresses the
- 15 -
'~?~
solubility but not the microdeposition power, which may be of
advantage.
Comprehensive tests have shown that polyester and cot-
ton textiles which have been washed with these depositor com-
pounds in the detergent formulation have shown very little loss
of brightness during 20 washing cycles, while washing without
these depositors shows the very well-known loss of brightness
. already after few washings. In all cases when brigh-tness has
been retained, the presence of Si can be cletected on the fibers
by electron initiated X-ray analyzing.
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