Note: Descriptions are shown in the official language in which they were submitted.
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Reduction of emissions of volatile compounds by additives
The invention relates to the use of special additives
for reducing the emission of volatile compounds from
compos i ti ons and p roducts whi ch comp ris a cons ti tuents whi ch
can form or release such volatile compounds. In particular,
the invention relates to the provision of additives for the
reduction of emissions of volatile compounds which are
potentially hazardous or cause unpleasant odour, such as HCN,
l0 amines and thio compounds.
The re a re many s ubs tances and compos i ti ons whi ch f o rm
or release volatile compounds which have unpleasant odour and
are potentially hazardous on accumulation. Depending on the
extent of the release or emission of volatile compounds, the
unpleasant odour or the potential hazard occurs in a range
whi ch extends f rom "not pe rceptible" o r "not p res ent" to
"predominant". In particular, a decrease of the emission is
desirable in the case of substances or compositions which
release the compounds in question to a relatively great
extent. Howeve r, even i n the cas a o f s ubs tances and compounds
whi ch releas a thes a s ubs tances i n amounts whi ch a re ve ry
small and are basically negligible, so that in the case of
correct handling, there is no question with regard to odour
pollution or safety hazard, a decrease in emissions can also
be desirable, however, in order to keep the safety margin,
until the individual MAK values are reached, as high as
possible.
Fo r exampl e, the re a re compos i ti ons f rom whi ch, unde r
ce rtai n condi ti ons , compounds s uch as H Q~1, ami nes s uch as NH3
and CH3NH2 o r thi o compounds s uch as HZ S, fo r example, a re
releas ed. In this cas e, a decreas a in the releas e, in
particular, of HCN is of interest, which can proceed in
highly variable extents from, for example, cyanide or
thi ocyanate i ons o r compounds havi ng cyani de o r thi ocyanate
3 5 s ubs ti tuents o r compos i ti ons comp ris i ng s uch compounds .
In addi ti on to the i no rgani c compounds , i n pa rti -
cula r, o rganothi ocyanates , whi ch i nclude a romati c and
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aliphati c o rganothi ocyanates , a re potenti al H CN s ou rces .
Examples of aliphatic and aromatic organothiocyanates are
thi ocyanate-s ubs ti tuted thi azoles , 3-thi ocyanato-N-
octylacrylamide and methylenebisthiocyanate (MSI') . They
frequently have a characteristic unpleasant odour and, under
certain conditions, also release volatile compounds such as,
for example, thio compounds and HCN. The emission values in
this cas a are, at leas t in the cas a of approved comme rci al
p roducts , wi thi n the pe rmi tted limi t values (MAK values ) ,
but, in principle, can also lie above these. Emissions of
this type and, in particular, elevated emissions, represent a
potenti al hazard to pe rs ons handli ng o r us i ng the p roducts
contai ni ng thes a cons ti tuents .
The contents of the i ndi vi dual compounds i n ques ti on
in the surrounding atmosphere serve, for example, as measured
parameter for the emission of a product, e. g. , for the
emission of HCN, the HCN content in the surrounding ai r
serves as indicator, in which case this can be determined
using an appropriate test tube (e. g. a Drager tube: prussic
acid 2/a (hydrogen cyanide) (CH 25701) ).
Quantitative determination of emissions such as HCN
is comparatively complex and frequently cannot be carried out
i n p cacti ce. To remedy this , the refo re, s ubj ecti ve
organoleptic tests, which give highly meaningful results, are
currently customarily also carried out. In this case, the
odour impression of the tested compositions is determined, a
reference sample being tested in conjunction.
The object therefore underlying the invention is to
reduce emissions of volatile compounds such as HCN, thio
3 0 compounds and ami nes , fo r example, whi ch a re potenti ally
hazardous or cause unpleasant odour, from compositions and
p roducts whi ch comp ris a cons ti tuents whi ch fo rm s uch
compounds which are potentially hazardous or cause unpleasant
odour, and, in this regard, to provide low-emission
3 5 compos i ti ons .
This object is achieved by means of the fact that
is othi azolone compounds s uch as N-octylis othi azolone and
benzis othi azolone, me rcapto compounds , cyclodext ri n
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compounds, iodopropynyl butylcarbamate and diiodomethyl
p-tolyl sulphone, zinc oxide, hydrogen peroxide, oz mixtures
o f two o r mo re s uch compounds , a re us ed as addi ti ve f o r the
reduction of emissions of volatile compounds which are
potenti ally hazardous o r caus a unpleas ant odou r f rom
' compos i ti ons whi ch comp ris a cons ti tuents whi ch fo rm s uch
compounds whi ch a re potenti ally haza rdous o r caus a unpleas ant
odou r.
Preferred embodiments are the subject-matter of the
l0 subclaims.
According to the invention, it has been found that
emissions which are potentially hazardous or have unpleasant
odour may be greatly reduced or eliminated by addition of the
abovementioned additive compounds. The extent of the emission
reducti on may be s et vi a the concept rati on of the addi ti ves .
In the case of products which already comply with the legally
prescribed limit values (MAK values ) , according to the
i nventi on, a fu rthe r reducti on o r a limi nati on o f s uch
emissions can increase the safety margin until the MAK values
2 0 a re reached, whe reas i n the cas a o f s ubs tances and compos i -
tions whose emission lies above this, a decrease or
elimination of the emissions can lead to the corresponding
comme rci al p roducts bei ng app roved o r bei ng abl a to be put on
the market.
The reduction can appear in advantages with respect
to odou r ve rs us a compa ris on p roduct whi ch contai ns no
additive according to the invention. The advantage achieved
is, for example, a reduction of the odour strength and/or a
change of the odour note or type of odour.
The following description, to illustrate the
invention, is essentially concerned with reducing the
emission of HCN from organothiocyanate compounds. However,
the i nventi on is not res t ri cted the reto, as the furthe r
qualitative results for emissions of thio compounds show. To
illustrate the reduction of HCN emissions, the test
s ubs tances s elected we re fi rs tly an a romati c
thiocyanatothiazole or 3-thiocyanato-N-octylacrylamide and
secondly aliphatic methylenebisthiocyanate (MBT).
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Suitable emission-reducing additives according to the
invention are, for example, the following isothiazolones and
mixtures of the same: N-octylisothiazolone, 5-chloro-N-
methylisothiazolone, N-methylisothiazolone, a mixture of
5-chloro-N-methylisothiazolone and N-methylisothiazolone,
1, 2-benzisothiazolone, 5, 6-dihydro-2-methyl-2H-
cyclopent(d)isothiazol-3(4H)-one. A suitable mercapto compound
is, for example, Pyrion disulphide. Suitable cyclodextrins
are, for example, a-, Vii- or y-cyclodextrin (cyclohexaamylose,
methylcycloheptaamylose or cyclooctaamylose). In addition,
iodopropynyl butylcarbamate, diiodomethyl p-tolyl sulphone,
zi nc oxi de and hydrogen pe roxi de a re s ui table.
The preferred emission-reducing additive is
N-octylis othi azolone. In the examples , the embodiments
acco rdi ng to the i nventi on p repa red a re p repa rati ons whi ch
comprise the emission-reducing additive, in particular an
isothiazolone, which reduces the emission of the preparations
and, i nte r ali a, als o acts as an HCN t rap.
The invention makes it possible to reduce the release
of HCN both i n aqueous s ys terns ove r a wi de pH range, s uch as
pH 1 to pH 12, e. g. by adding Ovate r-s oluble is othi azolones ,
s uch as N-methylis othi azolone, benzis othi azolone o r 5 , 6-
dihydro-2-methyl-2H-cyclopent(d)isothiazol-3(4H)-one, zinc
oxi de and hyd rogen pe roxi de, and i n li pophi li c medi a, e. g. by
adding N-octylisothiazolone.
According to the invention, therefore, in particular
HC~1 emissions can be reduced from primarily liquid products
(solutions, dispersions, preferably aqueous dispersions ) .
Si nce s ubs tances and compos i ti ons havi ng hi gh H CN
emissions are not suitable for the market, according to the
i nventi on, the pos s i bi li ty i s p rovi ded o f reduci ng thei r
emissions so greatly that marketing is thus possible.
Moreover, according to the invention, by adding the emission-
reducing additives, emissions which are already acceptable
and comply with current safety regulations can further be
dec reas ed, fo r example the o rganolepti c p rope rti es can als o
be imp roved, whi ch can lead to an i nc yeas ed ma rk et
acceptance.
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Furthermore, it is important that the action, e. g. a
biocidal action, ascribed to the treated compositions is not
impaired by the emission-reducing additives.
The invention can be used, for example, in the area
of solutions or dispersions for a fungicidal and algistatic
' finishing of materials and technical preservation. Concrete
areas of application and user products are, for example,
preservatives, disinfectants, impregnating agents, paints,
sizings and adhesives, primers, coatings, lubricants and
plasters.
The emission-reducing additives according to the
invention are used at least in a total amount of 0. O1 ~ by
weight, preferably 0.01 to 10.0 by weight, in particular 0.1
to 7.5 ~ by weight, and preferably 0.5 to 5. 0 ~ by weight,
based on the composition. When a plurality of emission-
reduci ng compounds a re us ed, the p ropo rti on o f each o f thes a
addi ti ve components can be s et acco rdi ng to the s peci fi c
product requi cements.
Experimental results are given below which indicate
the HCI~1 emission from aromatic organothiocyanate-containing
compositions or which confirm the emission-reducing action of
the s ai d addi ti ve compounds .
Aromatic organothiocyanate + HCN trap
Example I
Aqueous dispersions which comprised 7. 8 $ by weight of
aromatic organothiocyanate (in the form of 26~ by weight of a
30~ strength dispersion), based on the weight of the
dispersions, were admixed with various amounts of different
cyclodextrins ( 0. 5 °s, 1. 0 ~, 2. 0 ~, 3. 0 ~ and 5. 0 ~, bas ed on
the
weight of the dispersions, of cyclodextrin (CD) alpha
(Example Ia) or CD beta (Example Ib) or CD gamma (Example Ic)
t
and we re tes ted fo r compati bi li ty and s tabi li ty. The
procedure and the results of "HCN" measurements are reported
below.
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Appearance after storage at room temperature for 12 days or
~ n ~..oov~.
The dis pe rs i ons contai ni ng CD alpha and gamma
(Examples Ia and Ic) were unchanged with respect to
homogeneity and yellowish-white colour. In the case of the
dispersions containing CD beta (Example Ib), slightly
inhomogeneous, unstable brownish dispersions formed, in
pa rti cul a r at the hi ghe r content rati ons .
to Result:
Cyclodextrin alpha and cyclodextrin gamma lead to
homogeneous a romati c-o rganothi ocyanate-contai ni ng and
comparatively stable compositions. Cyclodextrin beta impai rs
the s tabi li ty and homogenei ty of aromati c-o rganothi ocyanate-
contai ni ng compos i ti ons .
Example II
Aqueous dispersions which comprised 7. 8 % by weight of
aromatic organothiocyanate (in the form of 26% by weight of a
% strength dispersion) , based on the weight of the
dispersions, were admixed with various amounts of N-
octylis othi azolone ( 45 % s t rength s oluti on) ( 0. 5 %, 1. 0 %, 2. 0 %,
3. 0 % o r 5 . 0 %, bas ed on the wei ght o f the dis pe rs i on ) and we re
25 tes ted for compatibi li ty and s tabi li ty. The procedure and
results of "HCt~T' measurements are reported below.
Appearance after storage at room temperature for 7 days:
After 7 days, homogeneous yellowish-white dispersions
3 o we re p res ent unchanged.
Example III
HCN measurements using a Draper test tube for HGN (see above)
(5 strokes ) for the dispersions of Examples I and II:
In this tes t, the Drape r tes t tube was us ed togethe r
wi th a pump. 8th ti ps o f the tube we re b rok en o f f and one
end o f the tube was then i ns a rted ti ght ly i nto the pump. The
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_ 7 _
HCN content was tested by holding the other end of the tube
in the air space over the surface of the respective sample in
a 50 ml wide-neck sample vial which was filled with 50 g of
the s ample. The tempe nature was 23. 5 ° C. The s ample vi als had
been sealed for 4 weeks. For measurement, the ai r was sucked
' through the tube. The measurement period was about 60 seconds
for 5 strokes and correspondingly about 24 seconds for 2
strokes. The result was then determined on the basis of the
coloration (reaction of HGN with HgCl2 and methyl red). The
meas a cement method co r res ponds to the Drage r i ns t ructi on
234-257 of 1995.)
Blank value (without additive, aromatic organo-
thi ocyanate-contai ni ng aqueous di s pe rs i ons ) --~ app rox. 1. 5
ppm.
Example Ia:+ 5 CD alpha --> approx. 1.5
o ppm
Example Ib:+ 5 CD beta -~ 1 - 1.5 ppm
o
Example Ib:+ 5 CD gamma ~ approx. 1.5 ppm
~
Example I + 5 N-octylis othi azolone-~ 0 ppm
I: ~
( 45 s t rength s oluti
o on )
HCN measurements using Drager tubes for HCN (see above)
(5 strokes ) for the dispersions according to Example II in a
250 ml wide-neck bottle which contained approximately 40 g of
the respective dispersion:
Blank value: approximately 1 - 2 ppm
All other samples: no HCN detectable! !
Result:
An addition of cyclodextrin somewhat decreases the
HCN emission of aromatic-organothiocyanate-containing
dispersions.
An addi ti on of N-octylis othi azolone ( 45 % s t rength
z
solution) significantly decreases the HCN emission of
a xomati c-o rganothi ocyanate-contai ni ng dis pe rs i ons .
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Example IV
Aqueous dispersions were produced which comprised
7. 8 % by weight of aromatic organothiocyanate (in the form of
13 % by wei ght o f a 60 % s t rength di s pe rs i on ) bas ed on the
wei ght o f the dis pe rs i ons . The dis pe rs i ons we re homogeneous
and whi tis h-yellow (ve ry hi gh quali ty) .
Example V
HCN measurements using Drager tubes (5 strokes) of the
dispersions of Example IV (aromatic organothiocyanate without
and wi th 1. 0 %, 2. 0 %, 3. 0 % and 5. 0 % N-octylis othi azolone ( 45 %
s t rength s oluti on )
The dispersions were measured after storage at room
temperature for 24 hours in a 250 ml wide-neck bottle which
contained approximately 100 g of the respective s ample:
Zero value After1 week at
room temperature
Blank: without 30 ppm > ppm
additive 3o
+ 1% Kathon 893 approx. 25 ppm 8 ppm
+ 2% Kathon 893 approx. 10 ppm 5 ppm
+ 3% Kathon 893 approx. 5 ppm 2-3 ppm
+ 5% Kathon 893 approx. 2 ppm 2 ppm
The dispersions remained unchanged with respect to
homogeneity and whitish-yellow colour. There was a marked
odour improvement with respect to the blank value.
The aromatic organothiocyanate content of the
dispersions containing 0 or 1 % N-octylisothiazolone (45 %
strength solution) was:
wi thout N-octylis othi azolone 7. 1 %
wi th 1 % N-octylis othi azolone 7. 1 %
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Res a 1 t:
An addi ti on of N-octylis othi azolone s i gni fi cantly
decreases the HCt~ emission of aromatic-organothiocyanate-
containing dispersions. The odour of such dispersions is
improved in this case. There is no decomposition of the
organothiocyanate active compound.
Example VI
Solutions containing aromatic organothiocyanate +
N-octylisothiazolone:
Li qui d p repa rati ons bas ed on a romati c o rgano-
thi ocyanate ( 60 o s t rength s oluti on) and N-octylis othi azolone
( 45 ~ s t rength s o luti on ) ( data i n pa its by wei ght ) , H CN
emission measurement (see above):
N-octylisothiazolone 0 90 80 70 60 50 40 30 20 10
( 45 s s t rength
s oluti on )
Organothiocyanate 100 10 20 30 40 50 60 70 80 90
60 ~ s t rength
s oluti on )
HCN emission in ppm, measured using Drager tubes at
22°C, measurement vessel 100 ml wide-neck bottle filled with
100 g of solution:
After 48 h < < < < 2
1 1 1 1
30
After 96 h < < < <
1 1 1 1
After 1 < < 1 1 2
1 1
week
The s oluti ons had not changed afte r s to rage at room
' 25 temperature for 2 months.
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Example VII
Solutions containing aromatic organothiocyanate +
N-oct~lisothiazolone:
Li qui d p repa rati ons bas ed on a romati c o rgano-
thi ocyanate ( 60 % s t rength s oluti on) and N-octylis othi azolone
45 % s t rength s oluti on ) ( data i n pa its by wei ght ) , H CN
emission measurement (see above):
N-octylisothiazolone8 6 4 2
( 45 % s t rength
solution)
Organothiocyanate 92 94 96 98
( 60 % s t rength
s oluti on)
HCN emission in ppm, measured using Drager tubes at
l0 22 ° C, measurement vess el 100 ml wide-neck bottle fi lled wi th
100 g of solution:
After 48 h 1-3 4-5 17 > 30a
After 1 week 2-3 5 7 17-18
2 s t rok es
Result:
B,~ addi ng N-octylis othi azolone to a romati c-
thiocyanate-containing solutions, homogeneous mixtures which
have a significantly decreased HCN emission are obtained in
all mixing ratios.
Further additives decreasing the HCN emission of aromatic
organothiocyanate
In the s tud_i es , furthe r H CN t raps we re found, whe re
i n each cas a homogeneous dis pe rs i on comp ri s i ng 7. 8 % by wei ght
of aromatic organothiocyanate was prepared containing 2% by
weight of active compound of the respective additive (in the
cas a of H202 ( 30 % s trength) i t was therefore 6. 66 % by
weight) , and the HCN emission was measured as a function of
time using a Drager tube.
HCL~T emission in ppm, measured using Drager tubes at
22 ° C, meas urement vess el 5 0 ml wi de-neck bottle fi lled wi th
25 g of dispersion:
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HCN trap HCN after pH
after 1 week after
48 h ppm 1
i n week
ppm
Wi thout addi ti on > 3 2 0 4 .
0 5
A) Cyclodextrin alpha 20 20 4.5
B) Cyclodextrin beta 25 20 4.5
C) Cyclodextrin beta 25 20 4.5
D) Cyclodextrin gamma 25 20 4.5
E ) Zi nc py ri thi one 25 25 4 .
7
F) 1, 2- Hsnzisothiazolone 5 < 1 4. 6
G) Pyrion disulphide 8 1-2 4.2
H) N-Methylisothiazolone 2-3 2 4.0
I) Iodopropynyl butylcarbamate 10-12 10 4.6
J) Hydrogen peroxide (30 s) 10 7 2. 7
K) Zi nc oxi de 6 8 7. 1
L) Henzothiophene-2-cyclohexyl- 20 20 4.1
ca rbami de S, S-di oxi de'
M) 5,6-Dihydro-2-methyl-2H-cyclo- 0 0 4.1
pent (d)isothiazol-3 (9H)-one"
N) PVP 25 25 4.0
O) PVP + hydrogen peroxide (30 ~) 18 720 2.5
"'
' 5 0 o acti ve content, i ni ti al content rati on = 4 ~
" 5 0 ~ acti ve content, i ni ti al content rati on = 4 0
"' 12 $ HZO2; i ni ti al content rati on = 16. 6 ~
Res ult: The fu rthe r addi ti ves s tudi ed lead to a reducti on
o f the H CN emis s i on, whi ch reducti on, i n comps ris on wi th the
isothiazolones, is somewhat lesser.
Preferred examples of these further additives lead to
a comparatively high reduction (to < 20 ppm) of the HCN
emission of aromatic-organothiocyanate-containing
compos i ti ons .
HCN emission and stability of commercial compositions which
- comprise aromatic organothiocyanate and N-.octylisothiazoione:
A tes t was made o f whethe r i ns tabi li ti es o r
reducti ons i n acti ve compound occu r du ri ng s to rage o f
i
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comme rci al compos i ti ons whi ch comp ris a a romati c o rgano-
thiocyanate and N-octylisothiazolone.
Res a 1 t:
An addition of N-octylisothiazolone to, for example,
fi lm p res a rvati ves bas ed on compos i ti ons whi ch contai ned
aromatic organothiocyanate, led to optically clear,
homogeneous solutions. The HCN emission was significantly
reduced. The active compound content is virtually unchanged
after storage at room temperature or +40°C for 1 month.
The same applies to the HCN emission of pure acrylic
mas on ry pai nt whi ch was t reated i n a co r res pondi ng manne r.
Res a 1 t:
At the application concentration, no HCN is
detectable and the s tabi li ty was excellent.
Example VIII
3-Thiocvanato-N-octvlacrvlamide:
Preparation of 3-thiocyanato-N-octylacrylamide and
N-octyl-3-thiocyanatoacrylamide from N-octylisothiazolone
(NOITZ, ext racted f rom N-octylis othi azolone ( 45 $ s t rength
s oluti on ) by s haki ng wi th toluene and wate r ) and KCN:
213 g (1 mol) of NOITZ + 65 g (1 mol) of KCN were
sti rred together in 600 ml of water. 10 $ strength HzS09 was
added dropwise with sti rring and cooling (maximum temperature
30°C). The mixture was stirred for 3 hours. The precipitate
was filtered off by suction, taken up in 500 ml of warm DIPE,
dried over Na2S09 and crystallized out with addition of
approximately 1.5 1 of PE. The crystals were filtered off by
s ucti on and was hed wi th PE. Af to r dryi ng, 145 . 4 g o f N-octyl-
3-thiocyanatoacrylamide (60.5 $ yield) resulted, in the form
of yellowish crystals, F: 81°C.
The 3-thiocyanato-N-octylacrylamide which was
isolated in crystalline form is vi rtually insoluble in water
(< 0. 01 $) and dissolves at about 2. 5 to 10 $ in glycols or
glycol ethe rs . The 2. 5 to 10 $ s t rength s oluti ons o f
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3-thiocyanato-N-octylacrylamide in glycols or glycol ethers
emit HCN, that is to say approximately 30 ppm (1 stroke)
after storage at room temperature for 1 week, whereas the
crystalline material had an HC'N emission of approximately
25 ppm at 5 strokes (Drager tube, see above).
Solvent: HC~T ( 1
stroke)
1,2-Propyl glycol approx. completely
2.5 $ soluble
Dipropyl glycol 10$ completely > = 40
soluble
Triethylene glycol 8$ completely approx. 30
s oluble
Phenoxypropanols 10$ completely approx. 30
s oluble
Phenoxyethanol 10$ completely approx. 30
s oluble
1-Methoxy-2- 10$ completely approx. 30
propanol soluble
Hityl diglycol 10 $ completely approx. 30
s oluble
Ethylene glycol 1$ completely approx. 30
soluble
Deioni zed water vi rtually
insoluble
(< 0.
O1 $)
All s oluti ons , afte r s to rage at room tempe rature fo r
2 months were without change, clear and slightly yellowish.
A 5 $ s t rength aqueous dis pe rs i on of 3-thi ocyanato-
N-octylacrylamide is almost white, homogeneous and has an HCN
emission of 13 ppm (5 strokes ) (Draper tube, see above) .
Adding, for example, N-octylisothiazolone
considerably decreased the HCN emission. The results were
roughly as fo r the o rganothi ocyanate tes ted.
Example IX
Emission of thio compounds:
An aqueous Pyri on dis ulphi de s oluti on ( contai ni ng
0. 84 $ active compound) was prepared from 7. 46 g (0. 02 mol)
Pyrion-Na (40 $ strength in water) , 1 g (0. O1 mol) of
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- 14 -
sulphuric acid 96~ and 1.18 g (0.011 mol) of H20Z 30$
strength in 100 g of deionized water. It was clear and
slightly yellow. A marked odour of thio compounds was noted.
If this solution was admixed with 10 g of a mixture
of 5-chloro-N-methylisothiazolone and N-methylisothiazolone
( app roximately 14 ~ by wei ght acti ve compound content ) , the
"thio odour" disappeared.
