U.S. patent application number 15/307143 was filed with the patent office on 2017-02-16 for anionic polyvinyl alcohol copolymer as protective colloid for pesticidal polyurea microcapsules.
The applicant listed for this patent is BASF SE. Invention is credited to Steven BOWE, Matthias BRATZ, Ewelina BURAKOWSKA-MEISE, Wolfgang DENUELL, John FRIHAUF, Joanna MECFEL-MARCZEWSKI, Ronald REPAGE.
Application Number | 20170042143 15/307143 |
Document ID | / |
Family ID | 50677951 |
Filed Date | 2017-02-16 |
United States Patent
Application |
20170042143 |
Kind Code |
A1 |
BURAKOWSKA-MEISE; Ewelina ;
et al. |
February 16, 2017 |
ANIONIC POLYVINYL ALCOHOL COPOLYMER AS PROTECTIVE COLLOID FOR
PESTICIDAL POLYUREA MICROCAPSULES
Abstract
The present invention relates to a process for producing
microcapsules which contain a shell and a core of a liquid
water-insoluble material, where (a) a premix (I) is prepared from
water and a protective colloid; (b) a further premix (II) is
prepared from the water-insoluble material and at least
bifunctional isocyanate (A) or a mixture of two or more different
isocyanates containing (A); (c) the two premixes (I) and (II) are
mixed together until an emulsion is formed; (d) at least a
bifunctional amine is then poured into the emulsion from step (c);
and (e) the emulsion is then heated until the microcapsules are
formed, and where the liquid water-insoluble material comprises a
pesticide, where the protective colloid is a polyvinyl alcohol
copolymer having hydrolysis degrees from 60 to 99.9%, and where the
polyvinyl alcohol copolymer contains comonomers with anionic
groups. Further subject matter are microcapsules obtainable by said
process. The present invention also relates to a method of
controlling phytopathogenic fungi and/or undesired plant growth
and/or undesired insect or mite attack and/or for regulating the
growth of plants, wherein the microcapsules are allowed to act on
the respective pests, their environment or the crop plants to be
protected from the respective pest, on the soil and/or on undesired
plants and/or on the crop plants and/or on their environment.
Inventors: |
BURAKOWSKA-MEISE; Ewelina;
(Reichenbach, DE) ; MECFEL-MARCZEWSKI; Joanna;
(Limburgerhof, DE) ; BRATZ; Matthias; (Maxdorf,
DE) ; DENUELL; Wolfgang; (Mannheim, DE) ;
BOWE; Steven; (Apex, NC) ; REPAGE; Ronald;
(Walldorf, DE) ; FRIHAUF; John; (Lincoln,
NE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Family ID: |
50677951 |
Appl. No.: |
15/307143 |
Filed: |
April 27, 2015 |
PCT Filed: |
April 27, 2015 |
PCT NO: |
PCT/EP2015/059001 |
371 Date: |
October 27, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62139819 |
Mar 30, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 8/11 20130101; A01N
25/28 20130101; A01N 37/22 20130101; B01J 13/18 20130101; A61K
9/5089 20130101; A01N 43/10 20130101; A61K 9/5026 20130101; A01N
43/56 20130101; B01J 13/14 20130101; C11D 3/3753 20130101; B01J
13/16 20130101; A61Q 19/00 20130101; C11D 17/0039 20130101; A01N
43/90 20130101 |
International
Class: |
A01N 25/28 20060101
A01N025/28; B01J 13/18 20060101 B01J013/18; A01N 43/56 20060101
A01N043/56; A01N 43/90 20060101 A01N043/90; A01N 43/10 20060101
A01N043/10; A01N 37/22 20060101 A01N037/22 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 29, 2014 |
EP |
14166360.9 |
Claims
1-15. (canceled)
16: A process for producing microcapsules which contain a shell and
a core of a liquid water-insoluble material, where (a) a premix (I)
is prepared from water and a protective colloid; (b) a further
premix (II) is prepared from the water-insoluble material and at
least bifunctional isocyanate (A) or a mixture of two or more
different isocyanates containing (A); (c) the two premixes (I) and
(II) are mixed together until an emulsion is formed; (d) at least a
bifunctional amine is then poured into the emulsion from step (c);
and (e) the emulsion is then heated until the microcapsules are
formed; and where the liquid water-insoluble material comprises a
pesticide, where the protective colloid is a polyvinyl alcohol
copolymer having hydrolysis degrees from 60 to 99.9%, where the
polyvinyl alcohol copolymer contains comonomers with anionic
groups, and wherein the isocyanate (A) is selected from alicyclic
or aliphatic isocyanates.
17: The process as claimed in claim 16, wherein the polyvinyl
alcohol copolymer contains comonomers with anionic groups selected
from carboxyl- and/or sulfonic acid groups.
18: The process as claimed in claim 16, wherein the polyvinyl
alcohol copolymer contains 0.1 to 30 mol % of the comonomers with
anionic groups.
19: The process as claimed in claim 16, wherein the polyvinyl
alcohol copolymer is used with amounts from 0.1 to 20% by weight,
based on the weight of the microcapsules.
20: The process as claimed in claim 16, wherein the water-insoluble
material comprises a pesticide blended with an oily solvent.
21: The process as claimed in claim 16, wherein the isocyanate (A)
is selected from hexamethylene diisocyanate or derivatives thereof,
or dicyclohexylmethane diisocyanates.
22: The process as claimed in claim 16, wherein a mixture of
isocyanate (A) and an anionically modified isocyanate (B) is used,
wherein the anionically modified diisocyanates (B) are selected
from the group which contain at least one sulfonic acid group in
the molecule.
23: The process as claimed in claim 22, wherein the weight ratio
between the isocyanates (A) and (B) is in the range from 10:1 to
1:10.
24: The process as claimed in claim 16, wherein the at least
bifunctional amine used is a polyethyleneimine.
25: The process as claimed in claim 16, where the pesticide has a
water-solubility up to 10 g/l at 20.degree. C.
26: The process as claimed in claim 16, wherein the core-shell
ratio (w/w) of the microcapsules is 20:1 to 1:10.
27: The process as claimed in claim 16, wherein microcapsules have
a diameter from 1 to 30 .mu.m.
28: The process as claimed in claim 16, wherein the emulsion is
then heated to at least 50.degree. C.
29: A method of controlling phytopathogenic fungi and/or undesired
plant growth and/or undesired insect or mite attack and/or for
regulating the growth of plants, wherein the microcapsules
obtainable by a process as defined in claim 16 are allowed to act
on the respective pests, their environment or the crop plants to be
protected from the respective pest, on the soil and/or on undesired
plants and/or on the crop plants and/or on their environment.
30: The method of claim 29, wherein the polyvinyl alcohol copolymer
contains comonomers with anionic groups selected from carboxyl-
and/or sulfonic acid groups.
31: The method of claim 29, wherein the polyvinyl alcohol copolymer
contains 0.1 to 30 mol % of the comonomers with anionic groups.
32: The method of claim 29, wherein the polyvinyl alcohol copolymer
is used with amounts from 0.1 to 20% by weight, based on the weight
of the microcapsules.
33: The process as claimed in claim 16, wherein the water-insoluble
material comprises a pesticide blended with an oily solvent.
34: The method of claim 29, wherein the isocyanate (A) is selected
from hexamethylene diisocyanate or derivatives thereof, or
dicyclohexylmethane diisocyanates.
35: The method of claim 29, wherein a mixture of isocyanate (A) and
an anionically modified isocyanate (B) is used, wherein the
anionically modified diisocyanates (B) are selected from the group
which contain at least one sulfonic acid group in the molecule.
Description
[0001] The present invention relates to a process for producing
microcapsules which contain a shell and a core of a liquid
water-insoluble material, where [0002] (a) a premix (I) is prepared
from water and a protective colloid; [0003] (b) a further premix
(II) is prepared from the water-insoluble material and at least
bifunctional isocyanate (A) or a mixture of two or more different
isocyanates containing (A); [0004] (c) the two premixes (I) and
(II) are mixed together until an emulsion is formed; [0005] (d) at
least a bifunctional amine is then poured into the emulsion from
step (c); and [0006] (e) the emulsion is then heated until the
microcapsules are formed, and where the liquid water-insoluble
material comprises a pesticide, where the protective colloid is a
polyvinyl alcohol copolymer having hydrolysis degrees from 60 to
99.9%, and where the polyvinyl alcohol copolymer contains
comonomers with anionic groups. Further subject matter are
microcapsules obtainable by said process. The present invention
also relates to a method of controlling phytopathogenic fungi
and/or undesired plant growth and/or undesired insect or mite
attack and/or for regulating the growth of plants, wherein the
microcapsules obtainable by said process are allowed to act on the
respective pests, their environment or the crop plants to be
protected from the respective pest, on the soil and/or on undesired
plants and/or on the crop plants and/or on their environment. The
present invention comprises combinations of preferred features with
other preferred features.
[0007] Microcapsules are usually spherical objects which consist of
a core and a wall material surrounding the core, wherein the core
is a solid, liquid or gaseous substance which is surrounded by the
solid (generally polymeric) wall material. They may be solid, i.e.
consist of a single material. Microcapsules may have a diameter
from 1 to 1000 .mu.m, on average.
[0008] A multitude of shell materials is known for producing the
wall of microcapsules. The shell can consist either of natural,
semisynthetic or synthetic materials. Natural shell materials are,
for example, gum arabic, agar agar, agarose, maltodextrins, alginic
acid or its salts, e.g. sodium alginate or calcium alginate, fats
and fatty acids, cetyl alcohol, collagen, chitosan, lecithins,
gelatin, albumin, shellac, polysaccharides, such as starch or
dextran, polypeptides, protein hydrolyzates, sucrose and waxes.
Semisynthetic shell materials are inter alia chemically modified
celluloses, in particular cellulose esters and cellulose ethers,
e.g. cellulose acetate, ethyl cellulose, hydroxypropylcellulose,
hydroxypropyl methylcellulose and carboxymethylcellulose, and also
starch derivatives, in particular starch ethers and starch esters.
Synthetic shell materials are, for example, polymers such as
polyacrylates, polyamides, polyvinyl alcohol or polyurea.
[0009] Depending on the type of shell material and the production
process, microcapsules are formed in each case with different
properties, such as diameter, size distribution and physical and/or
chemical properties.
[0010] Polyurea core-shell microcapsules obtained by reaction of
two diisocyanates and a polyamine are well known in the art.
[0011] To provide microcapsules with tailored properties novel
production processes need to be developed. Especially microcapsules
produced to encapsulate water-insoluble ingredients like oils need
to have an optimized, enhanced stability against leaking-out of the
oil from the capsules into the external phase, particularly in
surfactant-based formulations. Moreover, an aqueous dispersion of
the microcapsules needs to be stable against separation over a long
period of time.
[0012] There is an ongoing need to provide capsules for the
formulation of pesticides, where the capsule slowly releases the
pesticide over a prolonged period in order to decrease losses by
rain wash or detrimental effects such as phytotoxicity.
[0013] The problem was solved by a process for producing
microcapsules which contain a shell and a core of a liquid
water-insoluble material, where [0014] (a) a premix (I) is prepared
from water and a protective colloid; [0015] (b) a further premix
(II) is prepared from the water-insoluble material and at least
bifunctional isocyanate (A) or a mixture of two or more different
isocyanates containing (A); [0016] (c) the two premixes (I) and
(II) are mixed together until an emulsion is formed; [0017] (d) at
least a bifunctional amine is then poured into the emulsion from
step (c); and [0018] (e) the emulsion is then heated (e.g. up to at
least 50.degree. C.) until the microcapsules are formed, and where
the liquid water-insoluble material comprises a pesticide, where
the protective colloid is a polyvinyl alcohol copolymer having
hydrolysis degrees from 60 to 99.9% (preferably from 85 to 99.9%),
and where the copolymer contains comonomers with anionic groups. In
steps (a), (b), (c), (d), and (e) further auxiliaries may be
present and/or may be added.
[0019] The problem was also solved by microcapsules obtainable by
the process according to the invention.
[0020] According to the invention microcapsules with determined
sizes and/or size distribution can be produced in a targeted
manner. Moreover, it is possible to produce relatively small
microcapsules with diameters from 5 to 30 .mu.m. Advantageously,
capsules with greater enhanced leakage stability against leakage in
surfactant-based formulations are obtainable, which show a better
performance against separation over a long period of time.
[0021] According to the invention a mixture of bifunctional
isocyanates (A) and isocyanates (B) can be added in one step (e.g.
step (b)) or can be added separately from each other.
[0022] According to one embodiment of the invention the
bifunctional isocyanates (A) are dissolved alone or in a mixture
with a further isocyanate (B) in the water-insoluble liquid (also
termed "water-insoluble material") which later forms the core of
the microcapsules; the premixes (I) and (II) are mixed together
until an emulsion is formed and then the amine components are added
and the mixture is heated until the capsules are formed.
[0023] According to a second embodiment of the invention the
bifunctional isocyanates (A) are dissolved alone in the
water-insoluble material which later forms the core of the
microcapsules; the premixes (I) and (II) are mixed together until
an emulsion is formed and then the further isocyanate (B) is added
before the amine components are added and the mixture is heated
until the capsules are formed.
[0024] The temperature for the reaction of the isocyanates with the
amine components (e.g. in step (e)) may be at least 50.degree. C.,
better 60.degree. C., preferably 75 to 90.degree. C. and in
particular 85 to 90.degree. C., in order to ensure sufficiently
rapid reaction progress.
[0025] Here, it may be preferred to increase the temperature in
stages (e.g. in each case by 10.degree. C.) until then, following
completion of the reaction, the dispersion is cooled down to room
temperature (21.degree. C.).
[0026] The reaction time typically depends on the reaction amount
and temperature used. Usually, microcapsule formation is
established between ca. 60 minutes to 6 h or up to 8 h at the
temperatures defined above.
[0027] According to the present teaching, the addition of the amine
also preferably takes place with the input of energy, e.g. by using
a stirring apparatus.
[0028] In order to form an emulsion in the present process, the
respective mixtures are usually emulsified by processes known to
the person skilled in the art, e.g. by introducing energy into the
mixture through stirring using a suitable stirrer until the mixture
emulsifies. The pH is preferably adjusted using aqueous bases,
preference being given to using sodium hydroxide solution (e.g. 5%
strength by weight). It may be advantageous to adjust the pH of
premix (I) from 3 to 12, preferably between 4 to 10, and in
particular in the range from 5 to 10.
Microcapsules
[0029] The microcapsules are preferably obtainable by the process
according to the invention.
[0030] Within the context of the present teaching, the
microcapsules may have a shell made by a polyaddition between at
least bifunctional isocyanates with amines, preferably with
polyamines, which leads to polyurea derivatives.
[0031] The microcapsules are present in the form of aqueous
dispersions, the weight fraction of these dispersions in the
microcapsules being favored between 5 and 50% by weight, preferably
between 15 to 40% per weight and preferably 20 to 40% by weight.
The microcapsules usually have an average diameter in the range
from 1 to 500 .mu.m and preferably from 3 to 50 .mu.m or from 5 to
30 .mu.m. The particle size determinations specified may be carried
out by means of static laser diffraction. The d 50 and d 90 values
may be based on the volume distribution of the particles.
[0032] The microcapsules contain the liquid water-insoluble
material, e.g. an oil. The fraction of this oil can vary in the
range from 10 to 95% by weight, based on the weight of the
microcapsules, where fractions from 70 to 90% by weight may be
advantageous. Result of the process are microcapsules obtainable
which typical core-shell ratios (w/w) from 20:1 to 1:10, preferably
from 5:1 to 2:1 and in particular from 4:1 to 3:1.
[0033] The microcapsules which are obtainable by the present
processes are preferably free from formaldehyde.
Protective Colloid
[0034] It is state of the art to use protective colloids like
polyvinyl alcohols during the reaction between isocyanates and
amines.
[0035] Polyvinyl alcohol (=PVA) corresponds typically in general
according to formula
##STR00001##
with low amounts (up to 2%) of the formula structure
##STR00002##
[0036] In order to get the benefits of the invention it is
essential to use special protective colloids of polyvinyl alcohol.
It was found that the microcapsules have superior properties when
polyvinyl alcohol copolymers are used having a hydrolysis degree
from to 99.9% (preferably from 85 to 99.9%).
[0037] According to the invention the term "polyvinyl alcohol
copolymer" means a polymer of vinyl alcohol/vinyl acetate with
comonomers.
[0038] It is known that polyvinyl alcohol is produced by hydrolysis
(deacetylation) of polyvinyl acetate, whereby the ester groups of
polyvinyl acetate are hydrolysed into hydroxyl groups, thus forming
polyvinyl alcohol.
[0039] The degree of hydrolysis is a criteria of how many groups
are converted into hydroxyl groups. The term "polyvinyl alcohol" in
connection with a given degree of hydrolysis means therefore, in
fact, a vinyl polymer containing ester and hydroxyl groups.
[0040] According to the invention polyvinyl alcohol copolymers with
degrees of hydrolysis from 85 to 99.9%, especially between 85 to
95% may be used. In another form polyvinyl alcohol copolymers with
degrees of hydrolysis from 60 to 99.9%, preferably from 70 to 98%,
more preferably from 75 to 97%, and in particular from 85 to 96%
may be used.
[0041] The degree of hydrolysis of polyvinyl alcohol may be
determined according to DIN 53401.
[0042] The polyvinyl alcohol polymers according to the invention
contain additional comonomers, i.e. other comonomers are
polymerized together with vinylester in a first step, followed by
the hydrolysis of the ester groups to form the copolymer of
polyvinyl alcohol in a second step.
[0043] It is state of the art to prepare copolymers of polyvinyl
alcohol by a radical polymerization reaction between the vinyl
acetate and comonomers.
[0044] According to the invention polyvinyl alcohol copolymers
preferably contain unsaturated hydrocarbons as comonomers. These
unsaturated hydrocarbons are optionally modified with functional
non-charged and/or charged groups.
[0045] In particular the following comonomers are suitable:
unsaturated hydrocarbons having anionic groups like carboxyl-
and/or sulfonic acid groups. In another form the polyvinyl alcohol
copolymer contains comonomers with anionic groups selected from
carboxyl- and/or sulfonic acid groups. In another form the
polyvinyl alcohol copolymer contains 0.1 to 30 mol % (preferably
0.3 to 20 mol %, more preferably 0.5 to 10 mol %) of the comonomers
with anionic groups.
[0046] It is preferred according to the invention to use copolymers
of polyvinyl alcohol with hydrolysis degrees from 85 to 99.9,
preferred 85% to 95% and containing 0.1 to 30 mol % (preferably 0.3
to 20 mol %, more preferably 0.5 to 10 mol %) comonomers with
anionic groups like carboxyl- and/or sulfonic acid groups, wherein
mol % is based on polymerization mixture vinyl
acetate/comonomer.
[0047] In another form it is preferred according to the invention
to use copolymers of polyvinyl alcohol with hydrolysis degrees from
60 to 99.9, preferred 70% to 98%, and containing 0.1 to 30 mol %
(preferably 0.3 to 20 mol %, more preferably 0.5 to 10 mol %)
comonomers with anionic groups like carboxyl- and/or sulfonic acid
groups, wherein mol % is based on polymerization mixture vinyl
acetate/comonomer.
[0048] The polyvinyl alcohol copolymer may have a viscosity from 1
to 100 mPas, preferably from 1.5 to 70 mPas, more preferably from 2
to 50 mPas. The viscosity may be determined according to Brookfield
at 4% in water at 20.degree. C.
[0049] Suitable copolymers of polyvinyl alcohol and anionic
comonomers, are described in EP 2426172, EP 2648211, GB1438449 and
EP0291198, which disclosure is incorporated by reference.
[0050] Following protective colloids are particular suitable for
the production of microcapsules according to the invention: Anionic
polyvinyl alcohol copolymers with the hydrolysis degree
>80%-preferably 85.0%-99.5% and the viscosity 2 mPas-70 mPas (DP
100-6000). In another form anionic polyvinyl alcohol copolymers
with the hydrolysis degree from 60 to 99.9%, preferably from
85.0%-99.5%, and the viscosity from 2 mPas to 70 mPas (DP
100-6000). Examples of such type of colloids are: K-Polymer 25-88KL
from Kuraray (viscosity 20-30 mPas, hydrolysis 85.0-90.0%),
Gohsenal T-350 from Nippon Gohsei (viscosity 27-33 mPas, hydrolysis
93.0-95.0%), Gohseran L-3266 from Nippon Gohsei (viscosity 2.3-2.7
mPas, hydrolysis 86.5-89.0%).
[0051] The protective colloid can be, but does not have to be, a
constituent of the microcapsule shell.
[0052] In general, the protective colloids (e.g. the polyvinyl
alcohol copolymer) are used with amounts from 0.1 to 20% by weight,
but preferably in the range from 1 to 10% by weight and in
particular from 1.5 to 5% by weight, based on the weight of the
microcapsules. The weight of the microcapsules is usually based on
the total sum of the shell and the core materials, e.g. all
isocyanates, all bifunctional amines, all water-insoluble
materials, and the polyvinyl alcohol copolymer.
[0053] Combinations of two or more different protective colloids
may also be beneficial.
Isocyanates
[0054] Isocyanates are N-substituted organic derivatives
(R--N.dbd.C.dbd.O) of isocyanic acid (HNCO) tautomeric in the free
state with cyanic acid. Organic isocyanates are compounds in which
the isocyanate group (--N.dbd.C.dbd.O) is bonded to an organic
radical. Polyfunctional isocyanates are those compounds with two or
more isocyanate groups in the molecule.
[0055] According to the invention, at least bifunctional,
preferably polyfunctional, isocyanates are used as (A), i.e. all
aromatic, alicyclic and aliphatic isocyanates are suitable provided
they have at least two reactive isocyanate groups. Preferably, the
isocyanate (A) is an alicyclic or aliphatic isocyanate, wherein the
alicyclic isocyanate is even more preferred.
[0056] The suitable polyfunctional isocyanates (A) preferably
contain on average 2 to at most 4 NCO groups. Preference is given
to using diisocyanates, i.e. esters of isocyanic acid with the
general structure O.dbd.C.dbd.N--R--N.dbd.C.dbd.O, where R' here is
aliphatic, alicyclic or aromatic radicals.
[0057] Suitable isocyanates (A) are, for example, 1,5-naphthylene
diisocyanate, 4,4'-diphenylmethane diisocyanate (MOI), hydrogenated
MDI (H12MDI), xylylene diisocyanate (XDI), tetramethylxylol
diisocyanate (TMXDI), 4,4'-diphenyldimethylmethane diisocyanate,
di- and tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl
diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene
diisocyanate, the isomers of tolylene diisocyanate (TDI),
optionally in a mixture, 1-methyl-2,4-diisocyanatocyclohexane,
1,6-diisocyanato-2,2,4-trimethylhexane,
1,6-diisocyanato-2,4,4-trimethylhexane,
1-isocyanatomethyl-3-isocyanato-1,5,5-trimethylcyclohexane,
chlorinated and brominated diisocyanates, phosphorus-containing
diisocyanates, 4,4'-diisocyanatophenylperfluoroethane,
tetramethoxybutane 1,4-diisocyanate, butane 1,4-diisocyanate,
hexane 1,6-diisocyanate (HDI), dicyclohexylmethane diisocyanate,
cyclohexane 1,4-diisocyanate, ethylene diisocyanate, phthalic acid
bisisocyanatoethyl ester, also polyisocyanates with reactive
halogen atoms, such as 1-chloromethylphenyl 2,4-diisocyanate,
1-bromomethylphenyl 2,6-diisocyanate, 3,3-bischloromethyl ether
4,4'-diphenyldiisocyanate. Sulfur-containing polyisocyanates are
obtained, for example, by reacting 2 mol of hexamethylene
diisocyanate with 1 mol of thiodiglycol or dihydroxydihexyl
sulfide. Further suitable diisocyanates are trimethylhexamethylene
diisocyanate, 1,4-diisocyanatobutane, 1,2-diisocyanatododecane and
dimer fatty acid diisocyanate.
[0058] Suitable isocyanates of type (A) are at least bifunctional
compounds (i.e. compounds containing at least two isocyanate groups
--N.dbd.C.dbd.O). Typical representatives may be hexamethylene
diisocyanate (HDI), or derivatives thereof, e.g. HDI biuret
(commercially available e.g. as Desmodur N3200), HDI trimers
(commercially available as Desmodur N3300) or else
dicyclohexylmethane diisocyanates (commercially available as
Desmodur W). Toluene 2,4-diisocyanate or diphenylmethane
diisocyanate is likewise suitable.
[0059] Preferred according to the invention are isocyanates of type
(A), selected from the group consisting of hexane 1,6-diisocyanate,
hexane 1,6-diisocyanate biuret or oligomers of hexane
1,6-diisocyanate, in particular trimers thereof or
dicyclohexanemethylene diisocyanate. In another form the isocyanate
(A) is hexane 1,6-diisocyanate, hexane 1,6-diisocyanate biuret,
dicyclohexylmethane diisocyanates, or oligomers of hexane
1,6-diisocyanate.
[0060] One essential feature of the present process is the use of
two structurally different isocyanates (A) and (B).
[0061] The second isocyanate of type (B) is structurally different
from the isocyanate of type (A) and specifically the isocyanate of
type (B) could either be an anionically modified isocyanate or a
polyethylene oxide-containing isocyanate (or any desired mixtures
of these two isocyanate types).
[0062] The anionically modified isocyanates are known per se.
Preferably, these isocyanates of type (B) contain at least two
isocyanate groups in the molecule. One or more sulfonic acid
radicals are preferably present as anionic groups. Preferably,
isocyanates of type (B) are selected which are oligomers, in
particular trimers, of hexane 1,6-diisocyanate (HDI). Commercial
products of these anionically modified isocyanates are known, for
example, under the brand Bayhydur (Bayer), e.g. Bayhydur XP.
[0063] Polyethylene oxide-containing isocyanates (with at least two
isocyanate groups) are also known and are described, e.g. in U.S.
Pat. No. 5,342,556. Some of these isocyanates are self-emulsifying
in water, which may be advantageous within the context of the
present process since it may be possible to dispense with a
separate emulsifying step.
[0064] The weight ratio of the two isocyanates (A) and (B) is
adjusted preferably in the range from 10:1 to 1:10, more preferably
in the range from 5:1 to 1:5 and in particular in the range from
3:1 to 1:1.
[0065] It is also possible to use mixtures of different isocyanates
of types (A) and (B). Besides the isocyanates (A) and (B), further
isocyanates can also additionally be used in the process according
to the invention.
[0066] Preferably, however, a mixture of isocyanate (A) and an
anionically modified isocyanate (B) is used, wherein the
anionically modified diisocyanates (B) are selected from the group
which contains at least one sulfonic acid group, preferably an
aminosulfonic acid group, in the present process.
[0067] In another form In general it is preferred to use 0.5-12 wt.
%, in particular between 4-8 wt. %, total sum of isocyanates (A)
and (B) based on the total weight of the compounds used in the
process.
Amines
[0068] At least bifunctional amines, but preferably
polyethyleneimines (PEI), are used as further component in the
process according to the invention. Polyethyleneimines are
generally polymers in the main chains of which there are NH groups
which are separated from one another in each case by two methylene
groups:
##STR00003##
[0069] Polyethyleneimines belong to the polyelectrolytes and the
complexing polymers. Short-chain, linear polyethyleneimines with a
correspondingly high fraction of primary amino groups, i.e.
products of the general formula H.sub.2N CH.sub.2--CH.sub.2--NH
.sub.nH (n=2: diethylenetriamine; n=3; triethylenetetramine; n=4:
tetraethylenepentamine) are sometimes called polyethyleneamines or
polyalkylenepolyamines.
[0070] In the processes according to the invention,
polyethyleneimines with a molecular weight of at least 500 g/mol,
preferably from 600 to 30 000 or 650 to 25 000 g/mol and in
particular from 700 to 5000 g/mol or 850 to 2500 g/mol, are
preferably used. In general it is preferred to use 0.3-10 wt. %, in
particular between 0.5-5 wt. %, polyethyleneimines. In another form
In general it is preferred to use 0.3-10 wt. %, in particular
between 0.5-5 wt. %, polyethyleneimines based on the total weight
of the compounds used in the process.
[0071] In one form microcapsules are obtained with a diameter from
1 to 30 .mu.m comprising a liquid core of a water-insoluble
material, and a shell of a reaction product of an at least
bifunctional isocyanate (A) or a mixture of two or more different
isocyanates containing (A) and an at least bifunctional amine in
presence of polyvinyl alcohol copolymer with hydrolysis degrees
above 85 to 99.9% as a protective colloid.
Water-Insoluble Material
[0072] The microcapsules produced using the process described above
contain in the interior a material that is preferably
water-insoluble and liquid at 21.degree. C. (i.e. at 21.degree. C.,
a maximum of 10 g of the material can be dissolved in 1 l of
water). This includes all types of hydrophobic water-insoluble
liquids, and any blends thereof. Excluded are usually any
fragrances or perfumes as such materials.
[0073] This water-insoluble material is also referred to herein
below as "oil". These oils must be able, preferably without
auxiliaries, to dissolve the isocyanates in order to be able to use
them in the present process. Should an oil not ensure adequate
solubility of the isocyanates, there is the option of overcoming
this disadvantage by using suitable solubility promoters.
[0074] Besides the aforementioned oils, the microcapsules can also
have further, optionally liquid or solid, ingredients which are
dissolved, dispersed or emulsified in the oil in the
microcapsules.
[0075] The phrase "oil" in the context of the present invention
encompasses all kinds of oil bodies or oil components, in
particular vegetable oils like e.g. rape seed oil, sunflower oil,
soy oil, olive oil and the like, modified vegetable oils e.g.
alkoxylated sunflower or soy oil, synthetic (tri)glycerides like
e.g. technical mixtures of mono, di and triglycerides of C6-C22
fatty acids, fatty acid alkyl esters e.g. methyl or ethyl esters of
vegetable oils (Agnique.RTM. ME 18 RD-F, Agnique.RTM. ME 18 SD-F,
Agnique.RTM. ME 12C-F, Agnique.RTM. ME1270, all products of Cognis
GmbH, Germany) fatty acid alkyl esters based on said C6-C22 fatty
acids, mineral oils and their mixtures. In one form the oil
comprises preferably mineral oils.
[0076] Examples illustrating the nature of suitable hydrophobic
carriers without limiting the invention to these examples are:
Guerbet alcohols based on fatty alcohols having 6 to 18, preferably
8 to 10, carbon atoms, esters of linear C6-C22-fatty acids with
linear or branched C6-C22-fatty alcohols or esters of branched
C6-C13-carboxylic acids with linear or branched C6-C22-fatty
alcohols, such as, for example, myristyl myristate, myristyl
palmitate, myristyl stearate, myristyl isostearate, myristyl
oleate, myristyl behenate, myristyl erucate, cetyl myristate, cetyl
palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl
behenate, cetyl erucate, stearyl myristate, stearyl palmitate,
stearyl stearate, stearyl isostearate, stearyl oleate, stearyl
behenate, stearyl erucate, isostearyl myristate, isostearyl
palmitate, isostearyl stearate, isostearyl isostearate, isostearyl
oleate, isostearyl behenate, isostearyl oleate, cetyl myristate,
cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate,
cetyl behenate, cetyl erucate, behenyl myristate, behenyl
palmitate, behenyl stearate, behenyl isostearate, behenyl oleate,
behenyl behenate, behenyl erucate, erucyl myristate, erucyl
palmitate, erucyl stearate, erucyl isostearate, erucyl oleate,
erucyl behenate and erucyl erucate. Also suitable are esters of
linear C6-C22-fatty acids with branched alcohols, in particular
2-ethylhexanol, esters of C18-C38-alkylhydroxy carboxylic acids
with linear or branched C6-C22-fatty alcohols, in particular
Dioctyl Malate, esters of linear and/or branched fatty acids with
polyhydric alcohols (such as, for example, propylene glycol,
dimerdiol or trimertriol) and/or Guerbet alcohols, triglycerides
based on C6-C10-fatty acids, liquid mono-/di-/triglyceride mixtures
based on C6-C18-fatty acids, esters of C6-C22-fatty alcohols and/or
Guerbet alcohols with aromatic carboxylic acids, in particular
benzoic acid, esters of C2-C12-dicarboxylic acids with linear or
branched alcohols having 1 to 22 carbon atoms or polyols having 2
to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils,
branched primary alcohols, substituted cyclohexanes, linear and
branched C6-C22-fatty alcohol carbonates, such as, for example,
dicaprylyl carbonate (Cetiol.RTM. CC), Guerbet carbonates, based on
fatty alcohols having 6 to 18, preferably 8 to 10, carbon atoms,
esters of benzoic acid with linear and/or branched C6-C22-alcohols,
linear or branched, symmetrical or asymmetrical dialkyl ethers
having 6 to 22 carbon atoms per alkyl group, such as, for example,
dicaprylyl ether, ring-opening products of epoxidized fatty acid
esters with polyols, silicone oils (cyclomethicones, silicone
methicone grades, etc.), aliphatic or naphthenic hydrocarbons, such
as, for example, squalane, squalene or dialkylcyclohexanes, and/or
mineral oils. In one form the oil comprises preferably aliphatic or
naphthenic hydrocarbons, and/or mineral oils.
[0077] Within the context of the present invention, preferred oils
are, Guerbet alcohols based on fatty alcohols having 6 to 18,
preferably 8 to 10, carbon atoms, esters of linear C6-C22-fatty
acids with linear or branched C6-C22-fatty alcohols or esters of
branched C6-C13-carboxylic acids with linear or branched
C6-C22-fatty alcohols, such as e.g. myristyl myristate, myristyl
palmitate, myristyl stearate, myristyl isostearate, myristyl
oleate, myristyl behenate, myristyl erucate, cetyl myristate, cetyl
palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl
behenate, cetyl erucate, stearyl myristate, stearyl palmitate,
stearyl stearate, stearyl isostearate, stearyl oleate, stearyl
behenate, stearyl erucate, isostearyl myristate, isostearyl
palmitate, isostearyl stearate, isostearyl isostearate, isostearyl
oleate, isostearyl behenate, isostearyl oleate, cetyl myristate,
cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate,
cetyl behenate, cetyl erucate, behenyl myristate, behenyl
palmitate, behenyl stearate, behenyl isostearate, behenyl oleate,
behenyl behenate, behenyl erucate, erucyl myristate, erucyl
palmitate, erucyl stearate, erucyl isostearate, erucyl oleate,
erucyl behenate and erucyl erucate.
[0078] Also preferred oils are esters of linear C6-C22-fatty acids
with branched alcohols, in particular 2-ethylhexanol, esters of
C18-C38-alkylhydroxycarboxylic acids with linear or branched
C6-C22-fatty alcohols, linear or branched C6-C22-fatty alcohols, in
particular dioctyl malates, esters of linear and/or branched fatty
acids with polyhydric alcohols (such as e.g. propylene glycol,
dimerdiol or trimertriol) and/or Guerbet alcohols, triglycerides
based on C6-C10-fatty acids, liquid mono-/di-/triglyceride mixtures
based on C6-C18-fatty acids, esters of C6-C22-fatty alcohols and/or
Guerbet alcohols with aromatic carboxylic acids, in particular
benzoic acid, esters of C2-C12-dicarboxylic acids with linear or
branched alcohols having 1 to 22 carbon atoms or polyols having 2
to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils,
branched primary alcohols, substituted cyclohexanes, linear and
branched C6-C22-fatty alcohol carbonates, such as e.g. dicaprylyl
carbonate (Cetiol.TM. CC), Guerbet carbonates based on fatty
alcohols having 6 to 18, preferably 8 to 10, carbon atoms, esters
of benzoic acid with linear and/or branched C6-C22-alcohols (e.g.
Finsolv.TM. TN), linear or branched, symmetrical or asymmetrical
dialkyl ethers having 6 to 22 carbon atoms per alkyl group, such as
e.g. dicaprylyl ether (Cetiol.TM. OE), ring-opening products of
epoxidized fatty acid esters with polyols, silicone oils
(cyclomethicones, silicon methicone types etc.) and/or aliphatic or
naphthenic hydrocarbons, such as e.g. squalane, squalene or
dialkylcyclohexanes.
[0079] Furthermore, liquid linear and/or branched and/or saturated
or unsaturated hydrocarbons or any desired mixtures thereof can be
used as oils within the context of the present invention. These may
be e.g. alkanes having 4 to 22, preferably 6 to 18, carbon atoms,
or any desired mixtures thereof. Also of suitability are the
unsaturated hydrocarbons having 4 to 22 carbon atoms, or
unsaturated hydrocarbons of identical carbon number, and any
desired mixtures of these hydrocarbons. Cyclic hydrocarbons and
aromatics, e.g. toluene and mixtures thereof may also be oils
within the context of the present invention. In another preferred
form the oil comprises aromatics. Also suitable are silicone oils.
Any desired mixtures of all of the specified core materials are
also suitable.
[0080] It is also possible for other liquid, preferably
water-insoluble materials, such as biocides to be used and be
present in the microcapsules. Any desired mixtures of these further
materials may also be present in the microcapsules. In cases where
such material is not oil-soluble, additives may be used for
dispersing or emulsifying it. Otherwise, many actives, as for
example biocides or dyes often only available as blends with an
oily solvent. Those compositions are also useful in the context of
the present invention. In another preferred form the
water-insoluble material comprises a pesticide blended with an oily
solvent (also termed "oil" above). Most preferred is the use of
biocides (in particular pesticides), in the microcapsules of the
present invention.
[0081] In a more preferred form the water-insoluble material
comprises a pesticide blended with an oily solvent selected from
aliphatic and/or aromatic hydrocarbons.
Biocides
[0082] A biocide is a chemical substance capable of killing
different forms of living organisms used in fields such as
medicine, agriculture, forestry, and mosquito control. Usually,
biocides are divided into two sub-groups: [0083] pesticides, which
includes fungicides, herbicides, insecticides, algicides,
moluscicides, miticides and rodenticides, and [0084]
antimicrobials, which includes germicides, antibiotics,
antibacterials, antivirals, antifungals, antiprotozoals and
antiparasites.
Pesticides:
[0085] The U.S Environmental Protection Agency (EPA) defines a
pesticide as "any substance or mixture of substances intended for
preventing, destroying, repelling, or mitigating any pest". The
skilled worker is familiar with such pesticides, which can be
found, for example, in the Pesticide Manual, 16th Ed. (2013), The
British Crop Protection Council, London. A pesticide may be a
chemical substance or biological agent (such as a virus or
bacteria) used against pests including insects, plant pathogens,
weeds, mollusks, birds, mammals, fish, nematodes (roundworms) and
microbes that compete with humans for food, destroy property,
spread disease or are a nuisance. In the following examples,
pesticides suitable for the agrochemical compositions according to
the present invention are given:
Fungicides:
[0086] A fungicide is one of three main methods of pest
control--the chemical control of fungi in this case. Fungicides are
chemical compounds used to prevent the spread of fungi in gardens
and crops. Fungicides are also used to fight fungal infections.
Fungicides can either be contact or systemic. A contact fungicide
kills fungi when sprayed on its surface. A systemic fungicide has
to be absorbed by the fungus before the fungus dies. Examples for
suitable fungicides, according to the present invention, encompass
the following species: (3-ethoxypropyl)mercury bromide,
2-methoxyethylmercury chloride, 2-phenylphenol, 8-hydroxyquinoline
sulfate, 8-phenylmercurioxyquinoline, acibenzolar, acylamino acid
fungicides, acypetacs, aldimorph, aliphatic nitrogen fungicides,
allyl alcohol, amide fungicides, ampropylfos, anilazine, anilide
fungicides, antibiotic fungicides, aromatic fungicides,
aureofungin, azaconazole, azithiram, azoxystrobin, barium
polysulfide, benalaxy, l benalaxyl-M, benodanil, benomyl,
benquinox, bentaluron, benthiavalicarb, benzalkonium chloride,
benzamacril, benzamide fungicides, benzamorf, benzanilide
fungicides, benzimidazole fungicides, benzimidazole precursor
fungicides, benzimidazolylcarbamate fungicides, benzohydroxamic
acid, benzothiazole fungicides, bethoxazin, binapacryl, biphenyl,
bitertanol, bithionol, blasticidin-S, Bordeaux mixture, boscalid,
bridged diphenyl fungicides, bromuconazole, bupirimate, Burgundy
mixture, buthiobate, butyl-amine, calcium polysulfide, captafol,
captan, carbamate fungicides, carbamorph, carbanilate fungicides,
carbendazim, carboxin, carpropamid, carvone, Cheshunt mixture,
chinomethionat, chlobenthiazone, chloraniformethan, chloranil,
chlorfenazole, chlorodinitronaphthalene, chloroneb, chloropicrin,
chlorothalonil, chlorquinox, chlozolinate, ciclopirox, climbazole,
clotri-mazole, conazole fungicides, conazole fungicides
(imidazoles), conazole fungicides (triazoles), copper(II) acetate,
copper(II) carbonate, basic, copper fungicides, copper hydroxide,
copper naphthenate, copper oleate, copper oxychloride, copper(II)
sulfate, copper sulfate, basic, copper zinc chromate, cresol,
cufraneb, cuprobam, cuprous oxide, cyazofamid, cyclafuramid, cyclic
dithiocarbamate fungicides, cycloheximide, cyflufenamid, cymoxanil,
cypendazole, cyproconazole, cyprodinil, dazomet, DBCP, debacarb,
decafentin, dehydroacetic acid, dicarboximide fungicides,
dichlofluanid, dichlone, dichlorophen, dichlorophenyl,
dicarboximide fungicides, dichlozoline, diclobutrazol, diclocymet,
diclomezine, dicloran, diethofencarb, diethyl pyrocarbonate,
difenoconazole, diflumetorim, dimethirimol, dimethomorph,
dimoxystrobin, diniconazole, dinitrophenol fungicides, dinobuton,
dinocap, dinocton, dinopenton, dinosulfon, dinoterbon,
diphenylamine, dipyrithione, disulfiram, ditalimfos, dithianon,
dithiocarbamate fungicides, DNOC, dodemorph, dodicin, dodine,
DONATODINE, drazoxolon, edifenphos, epoxiconazole, etaconazole,
etem, ethaboxam, ethirimol, ethoxyquin, ethylmercury
2,3-dihydroxypropyl mercaptide, ethylmercury acetate, ethylmercury
bromide, ethylmercury chloride, ethylmercury phosphate,
etridiazole, famoxadone, fenamidone, fenaminosulf, fenapanil,
fenarimol, fenbuconazole, fenfuram, fenhexamid, fenitropan,
fenoxanil, fenpiclonil, fenpropidin, fenpropimorph, fentin, ferbam,
ferimzone, fluazinam, fludioxonil, flumetover, flumorph,
fluopicolide, fluoroimide, fluotrimazole, fluoxastrobin,
fluquinconazole, flusilazole, flusulfamide, flutolanil, flutriafol,
folpet, formaldehyde, fosetyl, fuberidazole, furalaxyl, furametpyr,
furamide fungicides, furanilide fungicides, furcarbanil,
furconazole, furconazole-cis, furfural, furmecyclox, furophanate,
glyodin, griseofulvin, guazatine, halacrinate, hexachlorobenzene,
hexachlorobutadiene, hexachlorophene, hexaconazole, hexylthiofos,
hydrargaphen, hymexazol, imazalil, imibenconazole, imidazole
fungicides, iminoctadine, inorganic fungicides, inorganic mercury
fungicides, iodomethane, ipconazole, iprobenfos, iprodione,
iprovalicarb, isoprothiolane, isovaledione, kasugamycin,
kresoxim-methyl, lime sulphur, mancopper, mancozeb, maneb, mebenil,
mecarbinzid, mepanipyrim, mepronil, mercuric chloride, mercuric
oxide, mercurous chloride, mercury fungicides, metalaxyl,
metalaxyl-M, metam, metazoxolon, metconazole, methasulfocarb,
methfuroxam, methyl bromide, methyl isothiocyanate, methylmercury
benzoate, methylmercury dicyandiamide, methylmercury
pentachlorophenoxide, metiram, metominostrobin, metrafenone,
metsulfovax, milneb, morpholine fungicides, myclobutanil,
myclozolin, N-(ethylmercury)-p-toluenesulphonanilide, nabam,
natamycin, nitrostyrene, nitrothal-isopropyl, nuarimol, OCH,
octhilinone, ofurace, organomercury fungicides, organophosphorus
fungicides, organotin fungicides, orysastrobin, oxadixyl, oxathiin
fungicides, oxazole fungicides, oxine copper, oxpoconazole,
oxycarboxin, pefurazoate, penconazole, pencycuron,
pentachlorophenol, penthiopyrad, phenylmercuriurea, phenylmercury
acetate, phenylmercury chloride, phenylmercury derivative of
pyrocatechol, phenylmercury nitrate, phenylmercury salicylate,
phenylsulfamide fungicides, phosdiphen, phthalide, phthalimide
fungicides, picoxystrobin, piperalin, polycarbamate, polymeric
dithiocarbamate fungicides, polyoxins, polyoxorim, polysulfide
fungicides, potassium azide, potassium polysulfide, potassium
thiocyanate, probenazole, prochloraz, procymidone, propamocarb,
pro-piconazole, propineb, proquinazid, prothiocarb,
prothioconazole, pyracarbolid, pyraclostrobin, pyrazole fungicides,
pyrazophos, pyridine fungicides, pyridinitril, pyrifenox,
pyrimethanil, pyrimidine fungicides, pyroquilon, pyroxychlor,
pyroxyfur, pyrrole fungicides, quinacetol, quinazamid,
quinconazole, quinoline fungicides, quinone fungicides, quinoxaline
fungicides, quinoxyfen, quintozene, rabenzazole, salicylanilide,
silthiofam, simeconazole, sodium azide, sodium
orthophenylphenoxide, sodium pentachlorophenoxide, sodium
polysulfide, spiroxamine, streptomycin, strobilurin fungicides,
sulfonanilide fungicides, sulfur, sultropen, TCMTB, tebuconazole,
tecloftalam, tecnazene, tecoram, tetraconazole, thiabendazole,
thiadifluor, thiazole fungicides, thicyofen, thifluzamide,
thiocarbamate fungicides, thiochlorfenphim, thiomersal,
thiophanate, thiophanate-methyl, thiophene fungicides, thioquinox,
thiram, tiadinil, tioxymid, tivedo, tolclofos-methyl, tolnaftate,
tolylfluanid, tolylmercury acetate, triadimefon, triadimenol,
triamiphos, triarimol, triazbutil, triazine fungicides, triazole
fungicides, triazoxide, tributyltin oxide, trichlamide,
tricyclazole, tridemorph, trifloxystrobin, triflumizole, triforine,
triticonazole, unclassified fungicides, undecylenic acid,
uniconazole, urea fungicides, validamycin, valinamide fungicides,
vinclozolin, zarilamid, zinc naphthenate, zineb, ziram, zoxamide
and their mixtures.
Herbicides:
[0087] An herbicide is a pesticide used to kill unwanted plants.
Selective herbicides kill specific targets while leaving the
desired crop relatively unharmed. Some of these act by interfering
with the growth of the weed and are often based on plant hormones.
Herbicides used to clear waste ground are nonselective and kill all
plant material with which they come into contact. Herbicides are
widely used in agriculture and in landscape turf management. They
are applied in total vegetation control (TVC) programs for
maintenance of highways and railroads. Smaller quantities are used
in forestry, pasture systems, and management of areas set aside as
wildlife habitat. In the following, a number of suitable herbicides
are compiled: [0088] 2,4-D, a broadleaf herbicide in the phenoxy
group used in turf and in no-till field crop production. Now mainly
used in a blend with other herbicides that act as synergists, it is
the most widely used herbicide in the world, third most commonly
used in the United States. It is an example of synthetic auxin
(plant hormone). [0089] Atrazine, a triazine herbicide used in corn
and sorghum for control of broadleaf weeds and grasses. It is still
used because of its low cost and because it works as a synergist
when used with other herbicides, it is a photosystem II inhibitor.
[0090] Clopyralid, a broadleaf herbicide in the pyridine group,
used mainly in turf, rangeland, and for control of noxious
thistles. Notorious for its ability to persist in compost. It is
another example of synthetic auxin. [0091] Dicamba, a persistent
broadleaf herbicide active in the soil, used on turf and field
corn. It is another example of synthetic auxin. [0092] Glyphosate,
a systemic nonselective (it kills any type of plant) herbicide used
in no-till burn down and for weed control in crops that are
genetically modified to resist its effects. It is an example of a
EPSPs inhibitor. [0093] Imazapyr, a non-selective herbicide used
for the control of a broad range of weeds including terrestrial
annual and perennial grasses and broadleaved herbs, woody species,
and riparian and emergent aquatic species. [0094] Imazapic, a
selective herbicide for both the pre- and post-emergent control of
some annual and perennial grasses and some broadleaf weeds.
Imazapic kills plants by inhibiting the production of branched
chain amino acids (valine, leucine, and isoleucine), which are
necessary for protein synthesis and cell growth. [0095]
Metoalachlor, a pre-emergent herbicide widely used for control of
annual grasses in corn and sorghum; it has largely replaced
atrazine for these uses. [0096] Paraquat, a nonselective contact
herbicide used for no-till burn down and in aerial destruction of
marijuana and coca plantings. More acutely toxic to people than any
other herbicide in widespread commercial use. [0097] Picloram, a
pyridine herbicide mainly used to control unwanted trees in
pastures and edges of fields. It is another synthetic auxin. [0098]
Triclopyr.
Insecticides:
[0099] An insecticide is a pesticide used against insects in all
developmental forms. They include ovicides and larvicides used
against the eggs and larvae of insects. Insecticides are used in
agriculture, medicine, industry and the household. In the
following, suitable insecticides are mentioned: [0100] Chlorinated
insecticides such as, for example, Camphechlor, DDT,
Hexa-chlorocyclohexane, gamma-Hexachlorocyclohexane, Methoxychlor,
Pentachlorophenol, TDE, Aldrin, Chlordane, Chlordecone, Dieldrin,
Endosulfan, Endrin, Heptachlor, Mirex and their mixtures; [0101]
Organophosphorus compounds such as, for example, Acephate,
Azinphos-methyl, Bensulide, Chlorethoxyfos, Chlorpyrifos,
Chlorpyriphos-methyl, Diazinon, Dichlorvos (DDVP), Dicrotophos,
Dimethoate, Disulfoton, Ethoprop, Fenamiphos, Fenitrothion,
Fen-thion, Fosthiazate, Malathion, Methamidophos, Methidathion,
Methyl-parathion, Mevinphos, Naled, Omethoate, Oxydemeton-methyl,
Parathion, Phorate, Phosalone, Phosmet, Phostebupirim,
Pirimiphos-methyl, Profenofos, Terbufos, Tetrachlorvinphos,
Tribufos, Trichlorfon and their mixture; [0102] Carbamates such as,
for example, Aldicarb, Carbofuran, Carbaryl, Methomyl,
2-(1-Methylpropyl)phenyl methylcarbamate and their mixtures; [0103]
Pyrethroids such as, for example, Allethrin, Bifenthrin,
Deltamethrin, Permethrin, Resmethrin, Sumithrin, Tetramethrin,
Tralomethrin, Transfluthrin and their mixtures; [0104] Plant toxin
derived compounds such as, for example, Derris (rotenone),
Pyrethrum, Neem (Azadirachtin), Nicotine, Caffeine and their
mixtures.
Rodenticides:
[0105] Rodenticides are a category of pest control chemicals
intended to kill rodents. In the following, examples for suitable
rodenticides are given: [0106] Anticoagulants, e.g. difenacoum,
brodifacoum, flocoumafen, bromadiolone, difethialone, warfarin,
coumatetralyl, chlorophacinone, diphacinone, coumachlor, coumafuryl
and pindone; [0107] Metal phosphides; [0108] Phosphides; or [0109]
Hypercalcemia, e.g. Calciferols (vitamins D), cholecalciferol
(vitamin D3) and ergocalciferol (vitamin D2).
Miticides, Moluscicides and Nematicides:
[0110] Miticides are pesticides that kill mites. Antibiotic
miticides, carbamate miticides, formamidine miticides, mite growth
regulators, organochlorine, permethrin and organophosphate
miticides all belong to this category. Molluscicides are pesticides
used to control mollusks, such as moths, slugs and snails. These
substances include metaldehyde, methiocarb and aluminium sulfate. A
nematicide is a type of chemical pesticide used to kill parasitic
nematodes (a phylum of worm). A nematicide is obtained from a neem
tree's seed cake; which is the residue of neem seeds after oil
extraction. The neem tree is known by several names in the world
but was first cultivated in India since ancient times.
[0111] The pesticide usually has a water-solubility up to 10 g/l,
preferably up to 5 g/l, and more preferably up to 1 g/l.
[0112] The pesticide may be solid or liquid at 20.degree. C.
[0113] The pesticide usually does not contain nucleophilic groups
selected from hydroxyl, thiol, primary nitrogen, secondary nitrogen
and carbanion.
[0114] Preferred pesticides are herbicides, insecticides and
fungicides, wherein herbicides are more preferred.
[0115] Examples of suitable herbicides are tepraloxydim,
flufenacet, napropamid, isoxaben, fluazifop-P-butyl, metamitron,
propyzamide, phenmedipham, clethodim, chloridazon, dimethenamid-P,
and pendimethalin. A preferred example is dimethenamid-P.
[0116] Besides the before mentioned compounds the microcapsules of
the present invention may also contain any desired blends of oils,
as well as blends of oil and water in emulsified form. Any kind of
emulsion (water-in-oil or oil-in-water, or multiple emulsions) is
possible.
[0117] For this purpose emulsifiers are needed: The microcapsules
according to the present invention might also contain one or more
emulsifier. Suitable emulsifiers are, for example, nonionic
surfactants from at least one of the following groups: products of
the addition of 2 to 30 mol ethylene oxide and/or 0 to 5 mol
propylene oxide onto linear C.sub.6-22 fatty alcohols, onto
C.sub.12-22 fatty acids, onto alkyl phenols containing 8 to 15
carbon atoms in the alkyl group and onto alkylamines containing 8
to 22 carbon atoms in the alkyl group; alkyl oligoglycosides
containing 8 to 22 carbon atoms in the alkyl group and ethoxylated
analogs thereof; addition products of 1 to 15 mol ethylene oxide
onto castor oil and/or hydrogenated castor oil; addition products
of 15 to 60 mol ethylene oxide onto castor oil and/or hydrogenated
castor oil; partial esters of glycerol and/or sorbitan with
unsaturated, linear or saturated, branched fatty acids containing
12 to 22 carbon atoms and/or hydroxycarboxylic acids containing 3
to 18 carbon atoms and addition products thereof onto 1 to 30 mol
ethylene oxide; partial esters of polyglycerol (average degree of
self-condensation 2 to 8), polyethylene glycol (molecular weight
400 to 5,000), trimethylolpropane, pentaerythritol, sugar alcohols
(for example sorbitol), alkyl gluco-sides (for example methyl
glucoside, butyl glucoside, lauryl glucoside) and polyglucosides
(for example cellulose) with saturated and/or unsaturated, linear
or branched fatty acids containing 12 to 22 carbon atoms and/or
hydroxycarboxylic acids containing 3 to 18 carbon atoms and
addition products thereof onto 1 to 30 mol ethylene oxide; mixed
esters of pentaerythritol, fatty acids, citric acid and fatty
alcohol and/or mixed esters of fatty acids containing 6 to 22
carbon atoms, methyl glucose and polyols, preferably glycerol or
polyglycerol, mono-, di- and trialkyl phosphates and mono-, di-
and/or tri-PEG-alkyl phosphates and salts thereof, wool wax
alcohols, polysiloxane/polyalkyl/polyether copolymers and
corresponding derivatives, block copolymers, for example
Polyethyleneglycol-30 Dipolyhydroxystearate; polymer emulsifiers,
for example Pemulen types (TR-1, TR-2) of Goodrich; polyalkylene
glycols and glycerol carbonate and ethylene oxide addition
products.
[0118] It is likewise possible for the ingredients to migrate from
the core of the microcapsules (i.e. the oil and/or further
materials present in the core) into the shell.
[0119] The invention further provides aqueous dispersions
comprising 5 to 50% by weight, based on the total weight of the
dispersion, preferably from 15 to 40% by weight, of microcapsules
which can be produced by the above process. A further preferred
range is between 20 and 35% by weight. These aqueous dispersions
are preferably obtainable directly from the process described
above.
[0120] The microcapsule dispersions which are obtainable by the
present process can be used in a large number of different
applications, depending on the type of oil.
[0121] The microcapsules may be present in form of an agrochemical
composition. An agrochemical composition comprises a pesticidally
effective amount of the microcapsules. The term "effective amount"
denotes an amount of the composition or of the microcapsules, which
is sufficient for combating undesired plant growth, and/or
infestation of plants by insects and/or infestation of plants by
phytopathogenic and which does not result in a substantial damage
to the treated plants. Such an amount can vary in a broad range and
is dependent on various factors, such as the fungal species to be
controlled, the treated cultivated plant or material, the climatic
conditions and the specific pesticide used.
[0122] The microcapsules of the invention can be formulated in a
variety of agrochemical compositions. Examples for agrochemical
composition types microcapsules formulations (e.g. CS, ZC), pastes,
pastilles, wettable powders or dusts (e.g. WP, SP, WS, DP, DS),
pressings (e.g. BR, TB, DT), granules (e.g. WG, SG, GR, FG, GG,
MG), insecticidal articles (e.g. LN), as well as gel formulations
for the treatment of plant propagation materials such as seeds
(e.g. GF). These and further compositions types are defined in the
"Catalogue of pesticide formulation types and international coding
system", Technical Monograph No. 2, 6.sup.th Ed. May 2008, CropLife
International.
[0123] The compositions are prepared in a known manner, such as
described by Mollet and Grubemann, Formulation technology, Wiley
VCH, Weinheim, 2001; or Knowles, New developments in crop
protection product formulation, Agrow Reports DS243, T&F
Informa, London, 2005.
[0124] The agrochemical compositions may contain the microcapsules
and auxiliaries.
[0125] Suitable auxiliaries are solvents, liquid carriers, solid
carriers or fillers, surfactants, dispersants, emulsifiers,
wetters, adjuvants, solubilizers, penetration enhancers, protective
colloids, adhesion agents, thickeners, humectants, repellents,
attractants, feeding stimulants, compatibilizers, bactericides,
anti-freezing agents, anti-foaming agents, colorants, tackifiers
and binders.
[0126] Suitable solvents and liquid carriers are usually water.
[0127] Suitable surfactants are surface-active compounds, such as
anionic, cationic, nonionic and amphoteric surfactants, block
polymers, polyelectrolytes, and mixtures thereof. Such surfactants
can be used as emulsifier, dispersant, solubilizer, wetter,
penetration enhancer, protective colloid, or adjuvant. Examples of
surfactants are listed in McCutcheon's, Vol. 1: Emulsifiers &
Detergents, McCutcheon's Directories, Glen Rock, USA, 2008
(International Ed. or North American Ed.).
[0128] Suitable anionic surfactants are alkali, alkaline earth or
ammonium salts of sulfonates, sulfates, phosphates, carboxylates,
and mixtures thereof. Examples of sulfonates are
alkylarylsulfonates, diphenylsulfonates, alpha-olefin sulfonates,
lignine sulfonates, sulfonates of fatty acids and oils, sulfonates
of ethoxylated alkylphenols, sulfonates of alkoxylated arylphenols,
sulfonates of condensed naphthalenes, sulfonates of dodecyl- and
tridecylbenzenes, sulfonates of naphthalenes and alkylnaphthalenes,
sulfosuccinates or sulfosuccinamates. Examples of sulfates are
sulfates of fatty acids and oils, of ethoxylated alkylphenols, of
alcohols, of ethoxylated alcohols, or of fatty acid esters.
Examples of phosphates are phosphate esters. Examples of
carboxylates are alkyl carboxylates, and carboxylated alcohol or
alkylphenol ethoxylates.
[0129] Suitable nonionic surfactants are alkoxylates, N-substituted
fatty acid amides, amine oxides, esters, sugar-based surfactants,
polymeric surfactants, and mixtures thereof. Examples of
alkoxylates are compounds such as alcohols, alkylphenols, amines,
amides, arylphenols, fatty acids or fatty acid esters which have
been alkoxylated with 1 to 50 equivalents. Ethylene oxide and/or
propylene oxide may be employed for the alkoxylation, preferably
ethylene oxide. Examples of N-substituted fatty acid amides are
fatty acid glucamides or fatty acid alkanolamides. Examples of
esters are fatty acid esters, glycerol esters or monoglycerides.
Examples of sugar-based surfactants are sorbitans, ethoxylated
sorbitans, sucrose and glucose esters or alkylpolyglucosides.
Examples of polymeric surfactants are home- or copolymers of
vinylpyrrolidone, vinylalcohols, or vinylacetate.
[0130] Suitable cationic surfactants are quaternary surfactants,
for example quaternary ammonium compounds with one or two
hydrophobic groups, or salts of long-chain primary amines. Suitable
amphoteric surfactants are alkylbetaines and imidazolines. Suitable
block polymers are block polymers of the A-B or A-B-A type
comprising blocks of polyethylene oxide and polypropylene oxide, or
of the A-B--C type comprising alkanol, polyethylene oxide and
polypropylene oxide. Suitable polyelectrolytes are polyacids or
polybases. Examples of polyacids are alkali salts of polyacrylic
acid or polyacid comb polymers. Examples of polybases are
polyvinylamines or polyethyleneamines.
[0131] Suitable adjuvants are compounds, which have a neglectable
or even no pesticidal activity themselves, and which improve the
biological performance of the pesticide on the target. Examples are
surfactants, mineral or vegetable oils, and other auxiliaries.
Further examples are listed by Knowles, Adjuvants and additives,
Agrow Reports DS256, T&F Informa UK, 2006, chapter 5.
[0132] Suitable thickeners are polysaccharides (e.g. xanthan gum,
carboxymethylcellulose), anorganic clays (organically modified or
unmodified), polycarboxylates, and silicates.
[0133] Suitable bactericides are bronopol and isothiazolinone
derivatives such as alkylisothiazolinones and
benzisothiazolinones.
[0134] Suitable anti-freezing agents are ethylene glycol, propylene
glycol, urea and glycerin.
[0135] Suitable anti-foaming agents are silicones, long chain
alcohols, and salts of fatty acids.
[0136] Suitable colorants (e.g. in red, blue, or green) are
pigments of low water solubility and water-soluble dyes. Examples
are inorganic colorants (e.g. iron oxide, titan oxide, iron
hexacyanoferrate) and organic colorants (e.g. alizarin-, azo- and
phthalocyanine colorants).
[0137] Suitable tackifiers or binders are polyvinylpyrrolidons,
polyvinylacetates, polyvinyl alcohols, polyacrylates, biological or
synthetic waxes, and cellulose ethers.
[0138] The agrochemical compositions generally comprise between
0.01 and 95%, preferably between 0.1 and 90%, and in particular
between 0.5 and 75%, by weight of the pesticide.
[0139] The agrochemical composition may be employed for the
purposes of treatment of plant propagation materials, particularly
seeds. The compositions in question give, after two-to-tenfold
dilution, active substance concentrations of from 0.01 to 60% by
weight, preferably from 0.1 to 40% by weight, in the ready-to-use
preparations. Application can be carried out before or during
sowing. Methods for applying the pesticide and compositions
thereof, respectively, on to plant propagation material, especially
seeds include dressing, coating, pelleting, dusting, soaking and
in-furrow application methods of the propagation material.
Preferably, the agrochemical compositions, respectively, is applied
on to the plant propagation material by a method such that
germination is not induced, e. g. by seed dressing, pelleting,
coating and dusting.
[0140] When employed in plant protection, the amounts of pesticide
applied are, depending on the kind of effect desired, from 0.001 to
2 kg per ha, preferably from 0.005 to 2 kg per ha, more preferably
from 0.05 to 0.9 kg per ha, and in particular from 0.1 to 0.75 kg
per ha.
[0141] In treatment of plant propagation materials such as seeds,
e. g. by dusting, coating or drenching seed, amounts of active
substance of from 0.1 to 1000 g, preferably from 1 to 1000 g, more
preferably from 1 to 100 g and most preferably from 5 to 100 g, per
100 kilogram of plant propagation material (preferably seeds) are
generally required.
[0142] When used in the protection of materials or stored products,
the amount of active substance applied depends on the kind of
application area and on the desired effect. Amounts customarily
applied in the protection of materials are 0.001 g to 2 kg,
preferably 0.005 g to 1 kg, of active substance per cubic meter of
treated material.
[0143] Various types of oils, wetters, adjuvants, fertilizer, or
micronutrients, and further pesticides (e.g. herbicides,
insecticides, fungicides, growth regulators, safeners) may be added
to the agrochemical compositions comprising them as premix or, if
appropriate not until immediately prior to use (tank mix). These
agents can be admixed with the compositions according to the
invention in a weight ratio of 1:100 to 100:1, preferably 1:10 to
10:1.
[0144] The user applies the agrochemical composition usually from a
predosage device, a knapsack sprayer, a spray tank, a spray plane,
or an irrigation system. Usually, the agrochemical composition is
made up with water, buffer, and/or further auxiliaries to the
desired application concentration and the ready-to-use spray liquor
or the agrochemical composition according to the invention is thus
obtained. Usually, 20 to 2000 liters, preferably 50 to 400 liters,
of the ready-to-use spray liquor are applied per hectare of
agricultural useful area.
[0145] The present invention further relates to a method of
controlling phytopathogenic fungi and/or undesired plant growth
and/or unde-sired insect or mite attack and/or for regulating the
growth of plants, wherein the microcapsules are allowed to act on
the respective pests, their environment or the crop plants to be
protected from the respective pest, on the soil and/or on undesired
plants and/or on the crop plants and/or on their environment.
[0146] Examples of suitable crop plants are cereals, for example
wheat, rye, barley, triticale, oats or rice; beet, for example
sugar or fodder beet; pome fruit, stone fruit and soft fruit, for
example apples, pears, plums, peaches, almonds, cherries,
strawberries, raspberries, currants or goose-berries; legumes, for
example beans, lentils, peas, lucerne or soybeans; oil crops, for
example oilseed rape, mustard, olives, sunflowers, coconut, cacao,
castor beans, oil palm, peanuts or soybeans; cucurbits, for example
pumpkins/squash, cucumbers or melons; fiber crops, for example
cotton, flax, hemp or jute; citrus fruit, for example oranges,
lemons, grapefruit or tangerines; vegetable plants, for example
spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes,
potatoes, pumpkin/squash or capsicums; plants of the laurel family,
for example avocados, cinnamon or camphor; energy crops and
industrial feedstock crops, for example maize, soybeans, wheat,
oilseed rape, sugar cane or oil palm; maize; tobacco; nuts; coffee;
tea; bananas; wine (dessert grapes and grapes for vinification);
hops; grass, for example turf; sweetleaf (Stevia rebaudania);
rubber plants and forest plants, for example flowers, shrubs,
deciduous trees and coniferous trees, and propagation material, for
example seeds, and harvested produce of these plants.
[0147] The term crop plants also includes those plants which have
been modified by breeding, mutagenesis or recombinant methods,
including the biotechnological agricultural products which are on
the market or in the process of being developed. Genetically
modified plants are plants whose genetic material has been modified
in a manner which does not occur under natural conditions by
hybridizing, mutations or natural recombination (i.e. recombination
of the genetic material). Here, one or more genes will, as a rule,
be integrated into the genetic material of the plant in order to
improve the plant's properties. Such recombinant modifications also
comprise posttranslational modifications of proteins, oligo- or
polypeptides, for example by means of glycosylation or binding
polymers such as, for example, prenylated, acetylated or
farnesylated residues or PEG residues.
[0148] The present invention further relates to seed containing the
microcapsules.
[0149] The present invention has various advantages: The invention
increases the stability of the formulation within broad range of
temperatures; the microcapsules may be loaded with both oil and
pesticide, and optionally adjuvants; the microcapsules have a
increased rainfastness; there is a reduced toxicological effect for
the worker and users; the microcapsules are very stable against
UV-light or sunlight; the microcapsules have a high physical
stability; the microcapsules have a excellent biodelivery; the
microcapsules have a very low toxicology (e.g. no eye irritation);
the microcapsules have a low contact angle of the sprayed drops on
leaves; the microcapsules have a high spreading on leaves. The
invention allows for a very slow release of the pesticide, e.g.
over at least 3 weeks. The invention allows for a reduced
phytotoxicity of pesticide; it is possible to mix the microcapsules
with water soluble or dispersed pesticides; or it is possible to
mix the microcapsules comprising a pesticide with microcapsules
comprising another pesticide; or it has a high efficacy.
[0150] The examples below give further illustration of the
invention, which is not, however, restricted to these examples.
EXAMPLE 1
Dimethenamid-P Microcapsules
[0151] Premix (I) was prepared from 50 g of carboxyl group-modified
anionic PVA (Kuraray Poval 25-88 KL from Kuraray with hydrolysis
degree 85%-90% and Brookfield viscosity 20.0-30.0 mPas at 4% in
water at 20.degree. C.) and 668 g of water.
[0152] Premix (II) was prepared from 611 g of dimethenamid-P
(DMTA-P,
S-2-chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)-acetami-
de, liquid, water-insoluble), 78 g of dicyclohexylmethane
diisocyanate and 22 g of Bayhydur.RTM. XP 2547 (anionic
water-dispersible polyisocyanate based on hexamethylene
diisocyanate; NCO about 22.5%, equivalent weight average about 182,
monomeric isocyanate <0.5%). These two premixes were combined
and emulsified with the help of a stirrer for 30 minutes at room
temperature at a speed of 700 rpm. Then, at room temperature a
solution of 40 g of Polyethyleneimine A (average molecular weight
2000, viscosity 10000-20000 mPas at 20.degree. C., pour point
-9.degree. C., water content <2.0%) in 75 g of water was
added.
[0153] The reaction mixture was then subjected to the following
temperature program: heating to 60.degree. C. in 60 minutes,
maintaining this temperature for 60 minutes, then 60 minutes at
70.degree. C., 60 minutes at 80.degree. C. and finally 60 minutes
at 85.degree. C. The mixture was then cooled to room temperature,
giving the desired microcapsule dispersion with a fraction of
nonvolatile components of 39.2% and a particle size d50=5
.mu.m.
EXAMPLE 2 (COMPARATIVE)
Variation of Capsule Wall
[0154] Premix (I) was prepared from 12 g of sodium lignosulfonate
(Reax.RTM. 88B) and 488 g of water. Premix (II) was prepared from
442 g of dimethenamid-P and 49 g of solvent free polyisocyanate
based on 4,4'-diphenylmethane diisocyanate (MDI) (average
functionality of 2,7, NCO content 32 g/100 g). These two premixes
were combined and emulsified with the help of a high shear
homogenizer for 2 minutes at room temperature at a speed of 7000
rpm. Afterwards, the emulsion was further stirred with a Mig
stirrer at room temperature with a stirring speed of 700 rpm. 75 g
of hexamethylenediamine was added over the course of 2 minutes. The
reaction mixture was then stirred at room temperature for 2 hours
to give the desired microcapsule dispersion with a fraction of
nonvolatile components of 54.2% and a particle size d50=7 .mu.m
[0155] The release rate of the pesticide from the microcapsules was
tested stirring the capsules at room temperature in water
containing 10 wt % surfactant to solubilize the released pesticide
in water. The amount of released pesticide was determined by
quantitative HPLC and compared to the release rate of the
microcapsules of Example 1. It was demonstrated that the use of the
shell wall according to Example 1 resulted in a slower release of
the pesticide.
TABLE-US-00001 TABLE 1 Released pesticide from microcapsules (% of
total pesticide) 5 7 21 10 min hours 1 day 3 days days 14 days days
Example 2 6.5 8.7 16.2 19.8 44.1 61.6 -- (Comparative) Example 1 0
0.4 1.5 4.5 9.5 17.1 28.5
EXAMPLE 3
Acetochlor Microcapsules
[0156] The synthesis of Example 1 is repeated with acetochlor
instead of dimethenamid-P at the same concentration. Microcapsules
with a similar particle size are obtained.
EXAMPLE 4
Metazachlor Microcapsules
[0157] The synthesis of Example 1 is repeated with metazachlor
instead of dimethenamid-P at the same concentration. Microcapsules
with a similar particle size are obtained.
EXAMPLE 5
Core with Pesticide and Oily Solvent
[0158] The preparation was made as described in Example 1, except
that premix (II) was prepared from 489 g of Dimethenamid-P, 122 g
of aromatic hydrocarbon solvent (distillation range 232 to
277.degree. C., aromatic content >99 vol %, viscosity 2.74
mm.sup.2/s at 25.degree. C.), 78 g of dicyclohexylmethane
diisocyanate and 22 g of Bayhydur.RTM. XP 2547. The resulting
microcapsule dispersion had a fraction of nonvolatile components of
39.8% and a particle size d50=4 .mu.m.
EXAMPLE 6 (COMPARATIVE)
Neutral Protective Colloid
[0159] The preparation was made as described in Example 5, except
that neutral polyvinylpyrrolidone (PVP K90) was used instead of
carboxyl group-modified anionic PVA at the same concentration.
[0160] The release rate of the pesticide from the microcapsules of
Example 6 was tested as in Example 2 and compared to the release
rate of the microcapsules of Example 5. It was demonstrated that
the use of the anionic protective colloid resulted in a slower
release of the pesticide.
TABLE-US-00002 TABLE 2 Released pesticide from microcapsules (% of
total pesticide) 10 min 5 hours 1 day 3 days 7 days 14 days Example
6 0.1 0.9 4.2 7.8 22.4 40.0 (neutral protective colloid) Example 5
0.1 0.4 1.3 3.1 6.6 12.4 (anionic protective colloid)
EXAMPLE 7 (COMPARATIVE)
Variation of Capsule Wall
[0161] Premix (I) was prepared from 12 g of sodium lignosulfonate
(Reax.RTM. 88B) and 480 g of water. Premix (II) was prepared from
370 g of dimethenamid-P, 96 g aromatic hydrocarbon solvent
(distillation range 232 to 277.degree. C., aromatic content >99
vol %, viscosity 2.74 mm.sup.2/s at 25.degree. C.), and 23 g of
solvent free polyisocyanate based on 4,4'-diphenylmethane
diisocyanate (MDI) (average functionality of 2,7, NCO content 32
g/100 g). These two premixes were combined and emulsified with the
help of a high shear homogenizer for 2 minutes at room temperature
at a speed of 7000 rpm. Afterwards, the emulsion was further
stirred at room temperature with a stirring speed of 700 rpm. 9 g
of hexamethylenediamine was added over the course of 2 minutes. The
reaction mixture was then stirred at room temperature for 2 hours
to give the desired microcapsule dispersion with a fraction of
nonvolatile components of 51% and a particle size d50=8 .mu.m
[0162] The release rate of the pesticide from the microcapsules of
Example 7 was tested (cf. Example 2) and compared to the release
rate of the microcapsules of Example 5. It was demonstrated that
the use of the shell wall according to Example 5 resulted in a
slower release of the pesticide.
TABLE-US-00003 TABLE 3 Released pesticide from microcapsules (% of
total pesticide) 10 min 5 hours 1 day 3 days 7 days 14 days Example
7 2.8 4.9 7.7 16.9 28.7 43.7 (Comparative) Example 5 0.1 0.4 1.3
3.1 6.6 12.4
EXAMPLE 8
Cinmethylin Microcapsules
[0163] The preparation was made as described in Example 1, except
that premix (II) was prepared from 611 g of Cinmethylin (liquid,
boiling point >300.degree. C., solubility in water about 0.06
g/l at 20.degree. C.), 78 g of dicyclohexylmethane diisocyanate and
22 g of Bayhydur.RTM. XP 2547. The resulting microcapsule
dispersion had a fraction of nonvolatile components of 39.5% and a
particle size d50=12 .mu.m.
EXAMPLE 9
Sulfonic Acid Modified Protective Colloid
[0164] The preparation was made as described in Example 1, except
that premix (I) was prepared from 50 g of sulfonic acid group
modified anionic PVA (Gohseran L-3266, Nippon Gohsei, with
hydrolysis degree 86.5%-89.5 mol % and viscosity of 2.3-2.7 mPas at
20.degree. C., 4% in water) and 668 g of water. The resulting
microcapsule dispersion had a fraction of nonvolatile components of
40.0% and a particle size d50=10 .mu.m.
EXAMPLE 10
Phytotoxicity
[0165] In greenhouse trials the postemergence crop safety and
phytotoxicity of dimethenamid-P on soybean and cotton. The plants
were treated with the aqueous tank mix via an AIXR Teejet spray
nozzle at the V2 (soybean) or 2 (cotton) growth stage at an
application rate of 15 gallons per acre (947 g/ha dimethenamid-P).
In all treatments glyphosate was included at a rate of 1120 g
ae/ha. The damage on the plants was visually assessed on 3 and 14
days after treatment (DAT).
[0166] The results in Tables 4 and 5 demonstrated that the
inventive Example 1 caused the least injury on the crop plants
compared to comparative Examples 2 and 7. During the tests there
was no nozzle clothing observed.
TABLE-US-00004 TABLE 4 Phytotoxicity (%) of dimethenamid-P on
soybean 3 DAT 14 DAT Example 1 11 21 Example 2 (comparative) 18 28
Example 7 (comparative) 17 30
TABLE-US-00005 TABLE 5 Phytotoxicity (%) of dimethenamid-P on
cotton 3 DAT 14 DAT Example 1 8 11 Example 2 (comparative) 24 27
Example 7 (comparative) 28 32
EXAMPLE 11
Phytotoxicity and Efficacy
[0167] In field trials in Brazil the phytotoxicity of
dimethenamid-P on soybean and its efficacy on weeds was tested. The
plants were treated with the aqueous tank mix at the V2 growth
stage at an application rate of 200 l/ha (840 g/ha dimethenamid-P).
In all treatments glyphosate was included at a rate of 1080 g/ha or
2160 g/ha, respectively. The damage on the plants was visually
assessed 7 days after treatment (DAT). For control some plants were
not treated. During the tests there was no nozzle clothing
observed.
[0168] The results in Tables 6 and 7 demonstrated that the
inventive Example 1 caused the least injury on the crop plants
compared to comparative Examples 2 and 7. The results in Tables 6
and 7 further demonstrated that the inventive Example 1 has similar
or even higher efficacy against weeds compared to comparative
Examples 2 and 7.
[0169] The efficacy on the following weeds was tested:
[0170] BRADC: Brachiaria decumbens, Surinam grass
[0171] ELEIN: Eleusine indica, Goosegras
[0172] COMBE: Commelina benghalensis, Bengal day flower
[0173] EPHHL: Euphorbia heterophylla, painted spurge
[0174] IPOTR: Ipomoea triloba, three-lobe morning glory
[0175] DIGHO: Digitaria horizontalis, tiende capote
TABLE-US-00006 TABLE 6 Phytotoxicity and efficacy (incl. 1080 g/ha
glyphosate) Untreated Example 2 Example 7 Control Example 1
(comparative) (comparative) Phytotoxicity 13.0 7.7 11.7 11.3 BRADC
4.7 91.7 96.0 91.7 ELEIN 1.7 100 100 100 COMBE 1.0 91.7 86.7 93.3
EPHHL 5.3 61.7 60.0 48.3 IPOTR 3.3 58.3 53.3 55.0 DIGHO 1.0 100 100
100
TABLE-US-00007 TABLE 7 Phytotoxicity and efficacy (incl. 2160 g/ha
glyphosate) Untreated Example 2 Example 7 Control Example 1
(comparative) (comparative) Phytotoxicity 13.0 7.7 11.7 11.3 BRADC
4.7 93.3 90.0 89.3 ELEIN 1.7 100 100 100 COMBE 1.0 92.7 90 88.3
EPHHL 5.3 66.7 70 63.3 IPOTR 3.3 60.0 60 65.0 DIGHO 1.0 100 98.3
100
* * * * *