METHOD FOR THE PREPARATION OF WATER DISPERSIBLE GRANULAR HERBICIDAL COMPOSITIONS WITH INCREASED THERMAL STABILITY

METHODE DE PREPARATION D'UN HERBICIDE GRANULE SOLUBLE A L'EAU, A STABILITE ACCRUE A LA CHALEUR

English Abstract

METHOD FOR THE PREPARATION OF WATER DISPERSIBLE GRANULAR
HERBICIDAL COMPOSITIONS WITH INCREASED THERMAL STABILITY
ABSTRACT
A method for the preparation of water dispersible
granular herbicidal compositions having increased thermal
stability. Compositions are described which contain low-
melting point substituted dinitroaniline compounds.

Claims

-22-
WHAT IS CLAIMED IS:
1. A method for the preparation of dispersible
granular compositions comprising: melting on a weight
basis about 20 to 70% of a compound having the following
structural formula
<IMG> (I)
wherein R1 is hydrogen, C1-C4 straight or branched-chain
alkyl, C3-C4 alkenyl or C3-C4 alkynyl; R2 is C1-C6 straight
or branched chain alkyl and optionally substituted with Cl
or OCH3, C3-C4 alkenyl or C3-C4 alkynyl, R3 is hydrogen,
CH3 or CH2OCH3; R4 is C1-C4 alkyl, CF3 or Cl; and mixing
with said melt on a weight basis about 1 to 3% of sodium
dioctyl sulfosuccinate or ethoxylated .beta.-diamines having
the following structural formula
<IMG>
wherein R5 is C9-C20 alkyl; and heating said mixture at
20 to 25°C above the melting point of the compound of
formula-(I); spraying said melt onto 5 to 25% by weight
of a highly sorptive hydrophilic or hydrophobic precipita-
ted or fumed silica or calcium silicate with agitation
until all of the melt is absorbed; cooling the thus
obtained mixture; adding a clay selected from attapulgite,
montmorillonite, bentonite or kaolin in amounts sufficient
to adjust the sum of all the other ingredient of the
composition to 100%; milling said mixture to a particle
size range of from 5 to 10µm; and granulating same with
an aqueous solution of 2 to 7.5% by weight of a wetting

-23-
agent selected from N-methyl-N-oleoyltaurate, octylphenoxy
polyethoxy ethanol, or nonylphenoxy polyethoxy ethanol,
and 2 to 6% by weight of a dispersing agent selected from
sodium lignin sulfonate and the sodium salt of a naphtha-
lene sulfonic acid-formaldehyde condensate.
2. A method according to Claim 1, wherein said
formula-(I) compound is selected from N-(1-ethylpropyl
2,6-dinitro-3,4-xylidine, .alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro-N,N-
dipropyl-p-toluidine or N-butyl-N-ethyl-.alpha.,.alpha.,.alpha.-trifluoro-2,
6-dinitro-p-toluidine and comprises 30 to 55% by weight
of the formulation.
3. A method according to Claim 2, wherein 40 to
55% by weight of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine
is melted with 1.5 to 2.5% by weight of sodium dioctyl
sulfosuccinate; the amount of highly sorptive silica is
15 to 25% by weight; the wetting agent is sodium N-methyl-
N-oleoyltaurate used in amounts of 2.5 to 5% by weight;
the dispersing agent is the sodium salt of naphthalene
sulfonic acid-formaldehyde condensate; the clay is benton-
ite used in amounts sufficient to total the formulation to
100%.
4. A method according to Claim 3, excepting that
0.5% by weight of fumed silica is used to coat the granules
and the amount of bentonite used is lowered by 0.5%.
5. A method according to Claim 3, wherein the
amount of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine is
51%; the amount of sodium dioctyl sulfosuccinate is 2.5%;
the amount of silica powder is 22.1%; the amount of
bentonite is 13.7%; the amount of sodium N-methyl-N-oleoyl-
taurate is 5% and the amount of the sodium salt of naphtha-
lene sulfonic acid-formaldehyde condensate is 2.5%; and the
amount of bentonite is sufficient to adjust the composition
to 100%.
6. The method according to Claim 5, wherein the
granules are coated with 0.5% by weight of fumed silica.
7. A dispersible granular composition of a 10
to 60 mesh size range comprising a mixture of 20 to 70% by

-24-
weight of a compound having a melting point below 100°C
and having the following structural formula
<IMG> (I)
wherein R1 is hydrogen, C1-C4 straight or branched-chain
alkyl, C3-C4 alkenyl or C3-C4 alkynyl; R2 is C1-C6 straight
or branched-chain alkyl and optionally substituted with
Cl or OCH3, C3-C4 alkenyl or C3-C4 alkynyl; R3 is hydrogen,
CH3 or CH2OCH3; R4 is C1-C4 alkyl, CF3 or Cl; and contain-
ing 1 to 3% by weight of sodium dioctyl sulfosuccinate or
an ethoxylated .beta.-diamine having the following structural
formula
<IMG> (II)
wherein R5 is C9-C20 alkyl, absorbed in the molten state
onto 5 to 25% by weight of a highly sorptive hydrophilic
or hydrophobic precipitated or fumed silica or calcium
silicate and a clay selected from attapulgite, montmoril-
lonite, bentonite or kaolin in amounts sufficient to adjust
the sum of all the other ingredient of said composition to
100% wherein said mixture comprises a particle size range
5 to 10µm prior to granulation with an aqueous solution of
2 to 7.5% by weight of a wetting agent selected from N-
methyl-N-oleoyltaurate, octylphenoxy polyethoxy ethanol,
and 2 to 6% by weight of a dispersing agent selected from
sodium lignin sulfonate and the sodium salt of a naphtha-
lene sulfonic acid-formaldehyde condensate.

Description

;~
28, 826
- ~202500
- 1-
METHOD FOR THE PREPARATION OF WATER DI SPERSIBLE GRANULAR
HERBICIDAL COMPOSITIONS WITH INCREASED THER~L STABILITY
The invention herein described relates to a novel
method for the preparation of water dispersible granular
compositions containing dinitroaniline herbicides having
the following structural formula:
; Rl \ ~ 2
N
02N ~ N02
R3 (I)
R4
wherein Rl is selected from H, Cl-C4 straight or branched-
; 15 chain alkyl, C3-C4 alkenyl or C3-C4 alkynyl; R2 is selected
rom Cl-C6 straight or branched-chain and optlonally
substituted with Cl or dCH3, C3-C4 alkenyl or C3-C4
alkynyl; R3 is H, CH3 or CH20CH3; R4 is Cl-C4 alkyl, CF3
or Cl. Compositions of the above hërbicides are charac-
terized by improved storage stability a~ elevated tempera-
tures.
By way of background, dinitroanaline herbicides
are disclosed in United States Patent Nos. 3,920,742;
4,098,812; 4,101,582; 4,124,639; and 49166,908. A number
of formula-(I) herbicides, such as N-(l-ethylpropyl)-2,6-
dinitro-3,4-xylidine, are desirable for the s,el-ective
control of certain grasses in the presence of agricultural
crops. Some formula-(I) compounds are efficacious for the
control of broadleaf weeds.
Customarily, such herbicides may be formulated
. ~.

~2~ S1~0
as wettable powders, dispersible granulars, emulsifiable
concentrates, flowables, or similar preparations. The
dispersible granular formulations offer ease of handling
coupled with redu~ed du~ting, and the absence o~ an
organic, flammable and possible toxic solvent that would
be present if an emulsifiable concentrate were used
instead.
Unf~rtunately, conventional dispersible granular
compositions (or wettable powders) containing formula-(I)
dinitroaniline herbicides which are solid at room tempera-
ture but have melting points below 100C, have a tendency
~o cake, fuse or lump-up when stored at or exposed to
elevated temperatures. This is due to excessive softening
or partial melting of the herbicides. In general, the
above referred-to conventional compositions are prepared by
blending and milling the appropriate amount of the selected
formula-(I~ dinitroaniline herbicide, a conventional inert
carrier, and one or more wetting and/or dispersing agent(s) 9
followed by granulating said blend in the appropriate
equipment using a binder solution as the granulating agent.
It has been unexpectedly discovered that the
method of present invention permits the preparation of
dispersable granular compositions which remain free-flowing
and do not agglomerate, lump-up or fuse when exposed to
elevated temperatures in the range of about 50C for a
prolonged period of time.
About 20 to 70% and preferably 30 to 55% by weight
of a dinitroaniline of formula-(I) is melted and heated
(preferably 20 to 25C above its melting point) and then
sprayed onto about 5 to 25% by weight of a highly sorptive
carrier selected from hydrophilic or hydrophobic precipi-
tated or fumed silicates or calcium silicates. This mixture
- is agitated until all of the molten herbicide ,is absorbed
and a free flowing powder is obtained. Next, a clay
selected from montmorillonite, attapulgite, bentonite or
kaolin is added in amounts sufficient to adjust the sum of
all the other ingredients of the composition to 100%. The
. .

~z~o~
mixture is then milled (preferably air-milled) to a 5 to
lO~m particle size range.
The thus obtained powder i9 then kept in motion
and sprayed with an aqueous solution containing from
about 2 to 7.5~/O by weight of a formulation of a wetting
agent selected from sodium N-methyl-N-oleoyltaurate,
octylphenoxy~or nonylphenoxy polyethoxy ethanol, or
sodium ~-olefin sulfonate, and a dispersing agent such as
sodium lignin sulfonate or the sodium salt of a naphthalene
sulfonic acid - formaldehyde condensate which has an
average molecular weight of about 600 to 800 Daltons.
Agitation continues until well-formed granules are
obtained. The granules are sorted through sieves to
obtain the desired size range, dried and if desired
blended with about 1 to 5% by weight of a hydrophobic
silica powder to enhance the free-flowing characteristics
of said formulation. The thus prepared granular composi-
tions resist caking and~or lumping when stored at or
exposed to temperatures in the range of about 50C, and
also disperse well in water without the formation of
large particles.
The approximate compositions of the various
clays listed above are tabulated helow in Table I. It
is recognized that said compositions may vary depending
on the origin of the clay in question.

~2~2S~
--4--
_ _
U~ o
c~ O ~ O O r~
o ~ a~ o I o o o o ~ I I I I
~: .
_ _ _ _
a~
C~ D O C~
o ~ 1-- o ~ ~ U~ ~ ~ ~ ,, ~ ~ ~o
V ~ o ~ o C~ o C~i o o ~ I o
~ ~D C`l
a~: :
. . _ .
~ a)
,~
~ o
4~ ~ U~
o ~,~ C~ ...... . . . . . .
1~ 1 ~ ~ O ~ a) o ~ I I 1--
o , , ,. , , , I U I ~i I
o oo~ C~ ~ ~ CO C~ oo
.,~ ~~D ~ O O
J- a~ ~ c:~ ~ JJ o
~ o ~ ~o o o
_ _ .
0?~
:
a~ ~
V
. r~ ~ co ~ .
~ ~ ~ o u~
¢ 0~ ~ C~ o o ~ o I I I I oo
0 ~
¢
~ .
~_ ~ O
O O
~ ,~
O O ~: o o
, C~ ~ ~_ 0 C~
~ ~ ~ Z ~ o
IJ ~ `~
O ~ r~ ) r1 x æ
c~ ~ x a ~ x o ~1
~ 0 1~ .1 0 ~-I ~ a o a) ^ c
.~ ~ rl X X .~ o
U~ ~_ X o ~ o X
~' ~n ~ ' ~i "~ ~ ^
c~ ~ n ~ n ~ o
O r-l ~r1 0 ~ n ,
r~ 5
1 ~ ~ V O ~ ~ O U~
I O O ~ 0 C~l O
'S ,~ F~ X C.) Ct~
.
~Y

~%~
-5
The surfactant, referred to hereinabove as
"octylphenoxy polyethoxy ethanol" has an average molecular
weight of 628 and contains an average of 9 to 10 ethylene
oxide units, representing 67% by weight, of said surfac-
tant. The specific gravity of this surfactant is 1.065at 25C; ~he viscosity is 240 cps at 25C (Brookfield;
12 rpm), and the flash point is >148C (TOC). Nonylphenoxy
polyethoxy e~hanol has an average molecular weight of
640 and contains an average of 9 to 10 ethylene oxide
units. The specific gravity of this surfactant is 1.056
at 25C, the viscosity is 240 cps at 25C (Brookfield;
12 rpm) and the flash point is >148C (TOC).
It should be noted that in the above prepara-
tion equally good results may be obtained if the solid
dinitroaniline herbicide of formula-(I) is added to the
agitated highly sorptive carrier which is preheated and
~aintained at a temperature range approximately 20 to
25C higher ~han the melting point of the respective
herbicide. As a further alternative, the molten herbicide
may be sprayed onto the preheated carrier. This mixture
is then cooled to room temperature prior to proceeding
with additional steps.
As stated above, the described method yields
free flowing non-agglomerating and non-caking compositions
of formula-(I) dinitroaniline herb;cides having melting
points below 100C. Expecially preferred are the herbi-
cides selected from: N-(l-ethylpropyl)-2,6-dinitro-3,4-
xylidine, ~ -trifluoro-2,6-dinitro-N,N-dipropyl-p-
toluidine and N-butyl-N-ethyl-~ -trifluoro-2,6-dinitro-
p-toluidine.
A further advantage of the method of the
present invention is that when certain of dlnitro-aniline
herbicides of formula-(I), which have the progerty of
existing in two polymorphic forms, are melt absorbed on
highly sorptive carriers of the types named above, they
are apparently inhibited from undergoing a polymorphic
change. This change normally occurs while said compounds

-6-
are stored, and usually culminates in the formation o~ large
crystals of the thermodynamically stable polymorphic form from
the originally microcrystalline, compounds of the metastable
; polymorphic form. The presence of such large crystals is undes-
ired in ready-to-use formulations since such crystals may clog
the spray delivery system, and may also result in nonuniform
distribution on the fields being sprayed. Although melt absor-
ption of dinitroaniline herbicides as described above inhibits
the formation of such large crystals, we prefer to use the methods
described and disclosed in United States Patent No. 4,082,537 and
in United States Patent No. ~,150,969. That is, we prefer to
incorporate from about 3g6 by weight of sodium dioctyl sulfosucci-
nate inhibitor or ethoxylated ~-diamine of the following structu-
ral formula:
R5-fH-CH3 fH2CH2OH
N-(CH2)3 N
CH2CH2OH CH2CH2OH (II)
wherein R5 is Cg-C20 alkyl, in the respective dinitroaniline
herbicide of formula-(I) prior to the preparation of the composi-
tions referred to in the body of the present application. If so
desired, other materials, such as ethyl cellulose may also be
used to improve the high-temperature storage stability of said
compositions.
Thus, the preparation of a typical formulation by the
method of the present invention may be illustrated as follows:
~.
`h

50~
-6a
On a weight basis, 56.97% of N~ ethylpropyl)-2,6-
dinitro-3,4-xylidine and 1.51% of sodium dioctyl sulfosuccinate
are heated to 70 to 75C until a homogenous melt forms. The
melt is maintained at 70 to 75C and is sprayed onto 20.76% by
weight of highly sorptive calcium silica-te while the latter is
being agitated by suitable means. When all of the melt is
absorbed, the powdery solid is cooled to room temperature and
13.79% by weight of bentonite is blended in. The mixture is then
,~,

~L2~
jet milled to a 5 to lO~m particle size range. The
resultant powder is tumbled in a suitable granulator and
sprayed with an aqueous solution containing 4.65% by
weight (of formulation) o sodium N-methyl-N-oleoyltaurate
and 2.32% by weight (of formulation) of the sodium salt
of naphthalene sulfonic acid - formaldehyde condensate.
The granules are then dried, separated to the desired
size range (i.e., about 10 to 60 mesh) and, if desired,
coated with about 1 to 5% by weight of a composition of
a finely divided sorptive substrate, such as calcined
powdered clays, diatomaceous earth, fumed silica,
fumed silica which has been made hydrophobic by the
replacement of most of the hydrophilic hydroxyl groups,
which normally populate the silica surface, with trimethyl
siloxyl groups as well as mixtures of said sorpti-~e
substrate, to aid in maintaining the free-flow characteris-
tics of said compositions.
The present invention is further illustrated
by the following examples which are not to be taken as
limitative thereof.
EXAMPLE 1
Evaluation of dispersible granular formulations of
dinitroaniline herbicides prepared by the method of the
invention.
The dinitroaniline herbicide and sodium
dioctyl sulfosuccinate are melted together and the melt
heated to 70 to 75C. The molten material is then sprayed
onto a highly sorptive silica with agitation, and agita-
tion continues until the melt is absorbed. Next, bentonite
is added and the mixture jet milled to a 5 to lO~m particle
size range. The milled powder is agitated and sprayed
with an aqueous solution of sodium N-methyl-N-oleoyltaurate
and the sodium salt of naphthalene sulfonic ac,id formalde-
hyde condensate. Agitation is continued until well formed
granules are obtained. The compositions of two formula-
tions is given in Table II below.
.

~zo~o
:
_ ' _ ~ _ _ _ _ N O
O C l O ~_ N ~ J ~ O
:) E _ _ _ _ _ ___
~ ~ ~ ~ ~ ~ ,o o C)
C ~0 l N ~ ~0 O O .
~ _~ __ _
~ : ~ ~ ~O C~ ~D ~ O
~ . ~ ~ t ~
¢S.. S. cr~ t- J a~ O O ~
:~ ~ bO (\~ l ~r) ~ O O Ir) ~J
bl~, . _ _ _ _ ____
~ 1.~ . ~C O .
a ~

~2al2S(~
g
:
The suspensibility of the above samples is
determined as follows: a 5.0 g sample of the appropriate
composition is mixed with 50 ml water. The resultant
mixture is stirred for 30 seconds, transferred to a 100 ml
5 ~ graduated cylinder, diluted to 100 ml volume, and mixed
throroughly by inverting the cylinder end-over-end 30
times at the rate of one complete cycle every 2 seconds.
The graduated cylinder is then allowed to stand in a water
bath for 30 minutes at 30C. A 25 ml aliquot is then
removed from approximately the middle of the graduated
cylinder, and evaporated to dryness. The residue is
weighed and the % suspension calculated. Another sample
of the suspension is filtered through a wet, 200-mesh
screen to determine the % retention. These tests are run
lS with standard hard water designed to provide a hardness of
342 ppm calculated ~as calcium carbonate [having the follow-
ing composition: 0.304 g CaC12 and 0.139 g MgC12.6H20 per
1000 ml H20] and standard soft water of 34.2 ppm hardness
(as CaCo3). The results are presented in Table III below.
.

l~OZSO~
~ -10-

12~250~
It can be seen from Table II above, ~hat the
granular com~ositions of the invention disperse well both
in soft and hard water and do no~ contain significant
amounts of large particles.
EXAMPLE 2
-
Pre aration of a dis ersible ranular herbicidal com-
P ~ g
position having improved thermal stability.
A sample of the herbicide N-(l-ethylpropyl~-
2,6-dinitro-3,4-xylidine (566.7 g of 90% pure effectively
giving 510 g containing 2.5% by weight of sodium dioctyl
sulfosuccinate) is melted. The melt is then heated to 70
to 75C. Next, a highly sorptive silica powder (221.2 g)
is agitated in a blender and sprayed wich the above molten
herbicide. Agitation continues until all of the molten
herbicide is absorbed. Bentonite (137.1 g) is added and
the blend is then micromilled to a 5 to lO~m particle size
range. The micromilled powder is agitated and is sprayed
while in motion with a solution of sodium N-methyl-N-
oleoyltaurate (S0.0 g) and the sodium salt of naphthalene
sulfonic acid condensate with formaldehyde (25.0 g) in 250
g water. Agitation of the blend continues until well-
formed granules are obtained. The granules are dried and
if so desired, coated with fumed silica (5.0 g), in which
case the amount of bentonite used is lowered by the corres-
ponding amount (5.0 g).
The thus obtained granules disintegrate well
in water and 98% of the particles of the suspension are
not larger than lO~m and not more than 0.5% is retained on
a 325 mesh sieve.
_ AMPLE 3
Comparison of the method of the invention with a con-
ventional preparation of herbicidal compositions to
evaluate the inhibition of polymorphic chan~es.
Two compositions are prepared as follows:
35 A. Sorptive, hydrophilic silica powder
(14.3 g) is agitated and sprayed with molten N-(l-ethyl-
propyl)-2,6-dinitro-3,4-xylidine (36.6 g; 92% pure) held

-12-
a~ 70 to 75C. Next, kaolin (12.0 g) is added and the
blend milled in a jet mill.
B. A control sample is prepared by milling
the above components, and in the same proportion, except
that the dinitroaniline herbicide is not added in a
molten form.
The samples are periodically observed under a
microscope for the presence or absence of the unwanted
orange macrocrystalline poIymorph of N~ ethylpropyl)-
2, 6-dinitro-3,4-xylidine. Results of this experiment
are presented in Table IV below.
.
~0
.

2~
,
- 1 3 -
: ~ ~ __
:~
~: ~ W ~ ~o
o
a) 3
U~
a
C~ ~ ~ O ~
r~ ~ ~ rC ~ ~ O
.~ O ~ ~ ~rl_~
0 ~
.,.~ O O ~ O O
~ :~; Ei O ~J~
a) _
~ . C~ O ~
'O l~i 0 r-(
~ ~ :~ W
~1 r~ C~ ~ O
QJ ~ a) . _
O ~ C~ O o
~ ~ ~ ~ ~1 ~
E~ ~ X ~ ~ JJ
4~ ~ ~ CO L~
C ~J __
,~ .~ O O
~:: .~ 0 '~0 O
.~ _, cn co u~
_ _
O
J~
O ~
. . .

~z~
_14-
The above data show that compositions prepared
by the melt absorption process of the invention
(Composition A) prevent and/or slow down the formation
of the unwanted orange macrocrystalline polymorph.
EXAMPLE 4
; Preparation of_a wettable herbicidal composition having
im~__ved stora~e stability at elevated temperatures.
~ Sorptive silica (16.2 g) is heated to and
agitated at 80C. A blend (17.8 g) comprising. 96.3%
of N~ ethylpropyl) 2,6-dini~ro-3,4-xylidine, 1.1% of
sodium dioctyl sulfosuccinate and 2.6% of ethyl cellulose
is added in small por~ions. The mixture is stirred and
heated until~ all of the molten herbicide is absorbed.
The mixture is then cooled to room temperature and blended
with sodium N-methyl-N-oleoyltaurate (2.0 g), the sodium
saIt of condensed naphthalene sulfonic acid (2.0 g) and
fumed silica (1.7 g). The thus obtained composition is
milled to a particle size range sufficiently small to
allow the entire sample to pass through a 200 mesh screen.
A sample of the above composition is stored
at 50C for 24 hours. This sample remained free-flowing
~no caking~ and also dispersed well in water.
EXAMPLE 5
Preparation of dispersible granular herbicidal composition
in which ranulation is accom~lished bY water onlY.
g
Hydrophilic silica (20.0 g) is agitated and
molten N~ ethylpropyl)-2,6-dinitro-3,4-xylidine (50.7 g,
91% pure; also contains 1.1% sodium dioctyl sulfosuccinate
and 2.6% ethyl cellulose) maintained at 75 to 80C is
sprayed on the silica. The coarse powder obtained is
blended with sodium N-methyl-N-oleoyltaurate (2.6 g), the
sodium salt of condensed naphthalene sulfonic acid (0.90 g)
and kaolin (25.80 g), and the blend milled to,a particle
size range sufficiently small to pass through a 200 mesh
screen.
A sample (10 g) of the thus obtained wettable
powder is agitated while being sprayed with water in

~2~D2
-15-
amounts sufficient to form granules which are then dried
and classified to a 10 to 30 mesh size range.
Part of the granules prepared as described
above are stored at 50C for 24 hours. Tests indicate
that both untreated and heat treated (stressed) granules
do not disperse well in water, larger (ca. 30 to 50~m)
particles~are present and some of the material is retained
on a 200 mesh screen.
EXAMPLE 6
Pre aration of dis ersible ranular herbicidal compositions
p _ p g
in which the herbicide is added as a solid material to a
heated carrier, and the product &ranulated by water only.
The appropriat~ sorptive carrier is agitated
at 60 to 70C and the solid dinitroaniline herbicide added
in small portions. Agitation of the mixture continues for
about 30 minutes at 60 to 70C untill all of the herbicide
is melted and absorbed on the carrier. The ~ixture is
then cooled down. The appropriate dispersing and/or
wetting agent(s) is (are) added followed by the addi~ion
of an inert diluent in amounts sufficient to adjust the
mixture to 100%. The thus obtained composition is blended
and milled to yield a wettable powder with a particle size
distribution such that the composition completely passes
through a 200 mesh screen.
The compositions obtained as described above
are agitated and sprayed with water to yield granules of
lO to 60 mesh size. The compositions prepared are summar-
ized in Table V below.

~25
-16-
c r---- 0 ~ ~ R~ r I
X ¦ ~ I ~ N ~ 5 ~
l ~ ¦ o ~ o ¦ I L ~ ~
~o ~ ~ t- ~ a~ 1~ cr~ : ~ '
~I ~ 5 N N _ N O D
D ¦ ¦ bO ¦ ~0 ~
~1 ~ ~- I -I 0~ -I c~ ~c
¦ ~- ~ ~
L ~ L 5 O O 5 3 5 ~ N
~ I R ~ R - ¦ R ¦ ~I f ~ ~ D ~ ~ ¦ R
C D. O ~ ~ ~3
n :3 ¦ - C C I a D ¦ Ei C

1~02S~)q)
-17-
Samples of each of the above granular
composition are stressed by storage at 50C for four days.
The stressed samples do not disperse well in water although
the wettable powders from which they were prepared have
satisfactory dispersion properties.
EXAMPLE 7
Preparation of wettable powders by conventional methods.
Precipitated silica, octylphenoxy polyethoxy
ethanol, sodium liqnin sulfonate and attapulgite are
thoroughly blended in predetermined proportions. The
resultant blend is agitated and sprayed with the appropri-
ate amount of molten dinitroaniline herbicide at a temper-
ature range of 70 to 80C. Following completion of this
addition the blend is allowed to cool and is then air
milled.
The composition of the samples prepared by
the above method is given in Table VI below.

~zo~o~
- 1 8 -
~ S~ ~ d
~ ~ o o o o o o
~ L ~J ~ O ~D ~ `D 3 O
0;
~o 1 t
~~ o o o o o o
D~D O l ~0 ~ ~0 3 O
D r--_ _ ----r r ~
.~ ~ '~ ~ l
a a o x O o c ,,' ' x na .
o o a 0 ¦ V I ~ ~ ~ c

-19--
Both of the above formulations failed to
absorb the molten dinitroaniline herbicide and on cooling
became~solid and lumpy and had to be hammer milled prior
to air milling. These powders did no~ disperse well in
water, nor could they be granulated in a satisfactory
manner.
EXAMPLE 8
-
Preparat on of dispersible ~ranular herbicidal compositions
dichloro hen l-l-methYl urea.
P Y
The appropriate amounts of l-butyl-3-(3,4-
dichlorophenyl)-l-methylurea, precipitated silica,
octylphenoxy polyethoxy ethanol, sodium lignosulfonate
and attapulgite are mixed and thoroughly blended. Next,
while be;ng agitated, the blend is sprayed with the appro-
priate amount of molten dinitroaniline herbicide main-
tained at 70 to 80C. The mixture is cooled, air milled,
and then granuiated with water using suitable equipment.
The granules are dried and classified according to the
desired particle size range.
These dispersible granular compositions are
then evaluated by the method of Example 1 as to their
suspensibility in water.
The composition of the formulations and the
results of the suspensibility tests are given in Tables
VII and VIIa below. It can be clearly seen that these
compositions and their method of preparation are inferior
as compared to those of the invention.

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