U.S. patent application number 14/738461 was filed with the patent office on 2015-10-01 for method for preparation of an aqueous glyphosate concentrate.
The applicant listed for this patent is Nufarm Australia Limited. Invention is credited to Aristos PANAYI, Chad Richard Ord SAYER, Allan SPENCER.
Application Number | 20150272112 14/738461 |
Document ID | / |
Family ID | 45891727 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150272112 |
Kind Code |
A1 |
SPENCER; Allan ; et
al. |
October 1, 2015 |
METHOD FOR PREPARATION OF AN AQUEOUS GLYPHOSATE CONCENTRATE
Abstract
A method for preparing an aqueous mixture of glyphosate salts to
improve the handling of the mixture, the method comprising forming
a homogeneous mixture of at least two bases comprising at least one
alkali metal hydroxide, and at least one further base selected from
alkali metal hydroxides and nitrogen bases and reacting the mixture
of the at least two bases with glyphosate acid in an aqueous
reaction medium to provide an aqueous mixture of glyphosate salts
wherein the concentration of glyphosate (based on glyphosate acid
equivalent) is at least 200 gae/L.
Inventors: |
SPENCER; Allan; (Ferntree
Gully, AU) ; PANAYI; Aristos; (Taylors Hill, AU)
; SAYER; Chad Richard Ord; (Brighton, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nufarm Australia Limited |
Laverton North |
|
AU |
|
|
Family ID: |
45891727 |
Appl. No.: |
14/738461 |
Filed: |
June 12, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13876935 |
Jun 27, 2013 |
9078431 |
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PCT/AU2011/001252 |
Sep 30, 2011 |
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14738461 |
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61431497 |
Jan 11, 2011 |
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61388670 |
Oct 1, 2010 |
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Current U.S.
Class: |
504/127 |
Current CPC
Class: |
A01N 37/04 20130101;
A01N 57/20 20130101; A01N 37/10 20130101; A01N 57/20 20130101; A01N
39/04 20130101; A01N 25/02 20130101; A01N 57/20 20130101; A01N
43/40 20130101; A01N 39/02 20130101; A01N 39/04 20130101; A01N
37/40 20130101; A01N 25/02 20130101; A01N 2300/00 20130101; A01N
37/40 20130101 |
International
Class: |
A01N 25/02 20060101
A01N025/02; A01N 37/40 20060101 A01N037/40; A01N 57/20 20060101
A01N057/20 |
Claims
1. A method for preparing an aqueous concentrate mixture comprising
salts of glyphosate and at least one other acid herbicide to
improve the handling of the mixture, the method comprising: forming
a homogeneous mixture of at least two bases comprising at least one
alkali metal hydroxide, and at least one further base selected from
alkali metal hydroxides and nitrogen bases, forming a mixture of at
least one other acid herbicide with glyphosate acid; and reacting
the mixture of the at least two bases with the mixture of
glyphosate acid and at least one other acid herbicide in an aqueous
reaction medium to provide an aqueous mixture of herbicide salts,
wherein the concentration of glyphosate (based on glyphosate acid
equivalent) is at least 200 gae/L and wherein the total acid
herbicide salts, including glyphosate is at least 360 gae/L and the
mole ratio of total alkali metal hydroxides and nitrogen
bases:total acid herbicides is in the range of 0.9:1 to 1.3:1.
2. The method according to claim 1 wherein said forming the
homogeneous mixture comprises forming a premix of bases by mixing
the bases to form the homogeneous mixture and wherein said reacting
comprises reacting the premix with the mixture of at least one
other acid herbicide with glyphosate acid in the aqueous reaction
medium.
3. The method according to claim 1 wherein the mixture of at least
two bases includes at least one nitrogen base selected from the
group consisting of ammonia, C.sub.1 to C.sub.10 alkylamine,
di-(C.sub.1 to C.sub.6 alkyl)amine, tri-(C.sub.1 to C.sub.6
alkyl)amine, C.sub.1 to C.sub.10 alkanolamine C.sub.1 to C.sub.6
alkyl(C.sub.1 to C.sub.6 alkanol)amines and di-(C.sub.1 to C.sub.6
alkyl)(C.sub.1 to C.sub.6 alkanol)amines.
4. The method according to claim 1 wherein the at least one alkali
metal hydroxide is selected from the group consisting of sodium
hydroxide, potassium hydroxide and lithium hydroxide.
5. The method according to claim 1 wherein the mixtures of bases
include at least two alkali metal hydroxides selected from the
group consisting of sodium hydroxide, potassium hydroxide and
lithium hydroxide.
6. The method according to claim 1 wherein when the mixture of
bases include potassium hydroxide and ammonia or isopropylamine
then at least one further base selected from said alkali metal
hydroxide and said nitrogen base is present.
7. The method according to claim 1 wherein when the mixture of
bases includes at least two of potassium hydroxide, ammonia and
isopropylamine then at least one further base is present selected
from said alkali metal hydroxide and said nitrogen base.
8. The method according to claim 1 wherein the concentrate of
glyphosate salts is at least 360 gae/L.
9. The method according to claim 1 wherein the concentrate of
glyphosate salts is at least 450 gae/L.
10. The method according to claim 1 wherein the concentration of
total acid herbicide salts, including glyphosate, is at least 450
gae/L.
11. The method according to claim 1 wherein the concentration total
acid herbicide salts, including glyphosate is at least 600
gae/L.
12. The method according to claim 1 wherein at least one nitrogen
base is present including at least one of ammonia, mono-(C.sub.1 to
C.sub.10) alkyl amines, di-(C.sub.1 to C.sub.4) alkyl amines and
tri-(C.sub.1 to C.sub.4 alkyl) amines.
13. The method according to claim 1 wherein the nitrogen bases
comprise at least one of ammonia, methylamine, dimethylamine,
isopropylamine, diisopropylamine, triethylamine.
14. The method according to claim 1 wherein the mixture of at least
two bases includes at least one selected from the group consisting
of sodium hydroxide, ammonium, methylamine, dimethylamine and
triethylamine.
15. The method according to claim 1 wherein the mixture of bases
includes at least three bases.
16. The method according to claim 1 wherein said reacting is
carried out at a temperature in the range of from 5.degree. C. to
80.degree. C.
17. The method according to claim 1 wherein the at least one other
acid herbicide is selected from the group consisting of dicamba,
clopyralid, picloram, 2,4-D, MCPA, 2,4-DB, mecoprop, mecoprop-P,
glufosinate, diclofop and fluazifop.
18. The method according to claim 1 wherein the at least one acid
herbicide is selected from the group consisting of dicamba,
clopyralid, 2,4-D, MCPA and mecoprop.
19. The method according to claim 1 further comprising addition of
a surfactant, at a concentration in the range of from 0.1 to 20% by
weight of the aqueous concentrate composition.
20. The method according to claim 19 wherein the surfactant
comprises one or more selected from the group consisting of
quaternary ammonium surfactant; etheramine surfactants; alkylether
and amine surfactant combinations; acetylenic diol and
alkyl(poly)glycoside surfactant combinations; lipophilic fatty
amine ethoxylate surfactants; alkoxylated amine surfactants;
betaine surfactants; alkyl polyglycoside agents; secondary or
tertiary alcohol surfactants; silicone copolymer wetting agents and
trialkylamine oxide or quaternary amine or trialkylbetaine
surfactant combinations; sorbitan fatty acid ester and amine,
quaternary ammonium or alkylglycoside surfactant combinations;
surfactants derived from alkanethiols; polyoxyalkylene trisiloxane
surfactants; super-wetting agents comprising silicone-based and
fluorocarbon-based surfactants; supra-molecular aggregates
comprising one or more amphiphilic salts having a glyphosate anion
and cation derived by protonation of secondary or tertiary oily
amines; falkoxylated primary alcohol surfactants; alkyl
polysaccharide derivates; alkyl polyglycoside and ethoxylated
alcohol combinations; alkylglucosides; surfactants comprising
polyhydroxyhydrocarbyl and amine functionality; alkylglycoside and
alkoxylated alkylamine surfactant combinations; alkyldiamine
tetraalkoxylate surfactants; succinic acid derivatives; alkoxylated
amido amines; sugar glycerides; diamine surfactants; widely-bridged
alcohol polyethoxylates; water-soluble long-chain hydrocarbyl
dimethylamine oxides and quaternary ammonium halide combinations;
hydroxyalkylammonium adjuvants; polyether diamine surfactants;
cationic, anionic, nonionic or zwitterionic silicone adjuvants;
organosilicone surfactants and diphenyl oxide sulfonate surfactant
combinations; a range of ether phosphate adjuvants; phosphorous
surfactant adjuvants; polyglycerol and polyglycerol derivatives;
C.sub.8-C.sub.22 sarcosinate or sarcosinate salts; ethoxylated
vegetable oils; polyethoxylated dialkylamine surfactants;
C.sub.10-C.sub.18 alkylpolyglycol ether sulfates; Sucrose &
Sorbital Surfactants; Sorbitan Esters; Ethoxylated Saccahrose
Esters; Coco Amido Propyl Dimethylamine Akyldimethylamines;
Phosphated Esters Tallow Amine Surfactants; Trisiloxanes; TEA and
MDEA Esterquats; Dimethylethanolamine based Esterquats;
Saccharides; Alkyl Polypentosides (APP); Polyglycerines; Etheramine
Alkoxylates; Sorbitan Monolaurate; Pine Terpinic compounds;
Cocoamine ethoxylates; Acrylates & Latex compounds;
(Ethoxylated) Oleyl Alcohols; Alkylamine Alkoxylates; Etheramine
Alkoxylates/Alkyl Etheramine; Quaternary Ammonium Salts/Ammonium
Quaternary Derivatives; Quat Amines; Amine Oxides; Dialkoxylates
Amines; Alkyl Alkoxylated Phosphates; Aminated Alkoxylated
Alcohols; Dialkoxylated Amines; Carboxylates; Alkylethersulfates;
Disodium sulfosuccinates/Succinates; Polyether Amines;
Cocoamidopropyl betaines and salts of fatty acids.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/876,935, which is a national stage
application under 35 U.S.C. .sctn.371 of PCT Application No.
PCT/AU2011/001252, filed Sep. 30, 2011, which claims the priority
benefit of U.S. Provisional Patent Application Ser. Nos.
61/388,670, filed Oct. 1, 2010, and 61/431,497, filed Jan. 11,
2011.
FIELD
[0002] The invention relates to a method of preparing an aqueous
concentrate of glyphosate involving neutralizing glyphosate acid
with a mixture of bases including an alkali metal base. The
invention further relates to a method of transport and handling of
glyphosate aqueous concentrates and the use of the aqueous
concentrates in controlling plant growth.
BACKGROUND
[0003] Glyphosate is commonly used and distributed as an aqueous
solution of a glyphosate salt such as the isopropyl ammonium
potassium or ammonium salts.
[0004] In order to reduce the transport and handling costs
associated with glyphosate concentrates it is desirable to use a
high loading of glyphosate, that is, the amount of active (usually
expressed as glyphosate acid equivalent per liter of aqueous
formulation) is desirably high within the bounds of the solubility
and ability to conveniently pour and dilute the concentrate.
[0005] U.S. Pat. No. 6,544,930 (Wright) reports that high loadings
can be achieved using the potassium salt of glyphosate and
compositions of the potassium salt are available at loadings of 540
g acid equivalent (ae) per liter of aqueous formulation.
[0006] International Patent Publication No. WO 01/26469 discloses
that aqueous formulations of glyphosate, including highly
concentrated formulations, can be prepared using a mixture of
glyphosate isopropyl amine and ammonium salts particularly in a
weight ratio (expressed on a glyphosate ae basis) of 80:20 to
97:3.
[0007] U.S. Pat. No. 6,881,707 (Howat and Hay) reports a glyphosate
composition comprising a mixture of salts of glyphosate comprising
each of potassium and isopropylammonium salts. International
Publication WO2006/023431 asserts that loadings of at least about
400 g glyphosate acid equivalent can be obtained by formulating in
aqueous solution a mixture of salts of glyphosate at a total
glyphosate ae concentration not less than about 360 gae/L, wherein
(a) said glyphosate is in anionic form accompanied by low molecular
weight non-amphiphilic cations in a total molar amount of about
100% to about 120% of the molar amount of said glyphosate; (b) said
cations comprise potassium and propylammonium (e.g., IPA) cations
in a mole ratio of about 70:30 to about 90:10; and (c) said
potassium and propylammonium cations together constitute about 90
to 100 molar percent of all of said low molecular weight
non-amphiphilic cations in the composition. The patent reports
formulations of up to 590 g glyphosate acid equivalent per liter of
aqueous formulation.
[0008] The concentrate formulation of glyphosate can be difficult
to handle due to viscosity, particularly at low temperatures and
high loadings of active. At high loadings the viscosity of the
composition is increased to such an extent that it is often
difficult to dispense the aqueous solution by pouring or pumping
with normal pump equipment. Also the solution stability of the
salts may be compromised, particularly at low temperatures so that
precipitates form at low temperature which can not be readily
resuspended or solubilised.
[0009] The discussion of documents, acts, materials, devices,
articles and the like is included in this specification solely for
the purpose of providing a context for the present invention. It is
not suggested or represented that any or all of these matters
formed part of the prior art base or were common general knowledge
in the field relevant to the present invention as it existed before
the priority date of each claim of this application.
SUMMARY
[0010] We provide a method for preparing a glyphosate herbicidal
aqueous concentrate to improve the handling and stability thereof,
the method comprising forming a homogeneous mixture of al least two
bases comprising one base selected from alkali metal hydroxides and
at least one further base selected from alkali metal hydroxides and
nitrogen bases and reacting the mixture of the at least two bases
with glyphosate acid in an aqueous reaction medium to provide an
aqueous mixture of glyphosate salts wherein the concentration of
glyphosate (based on glyphosate acid equivalent which is
abbreviated as "ae") is at least 200 gae/L and preferably, at least
360 gae/L.
[0011] The method uses a premix of at least one alkali metal base
selected from alkali metal hydroxides and at least one further base
selected from alkali metal hydroxide and nitrogen base.
[0012] The mixture of bases preferably includes at least one
nitrogen base which is preferably selected from the group
consisting of ammonia, ammonium hydroxide, C.sub.1 to C.sub.10
alkylamine, di-(C.sub.1 to C.sub.6 alkyl)amine, tri-(C.sub.1 to
C.sub.6 alkyl)amine and C.sub.1 to C.sub.10 alkanolamine.
[0013] The concentration of glyphosate salts preferably is at least
450 gae/L, more preferably at least 500 gae/L, still more
preferably at least 550 gae/L and still more preferably 600 gae/L,
such as at least 610 gae/L, at least 620 gae/L, at least 630 gae/L
and at least 640 gae/L, at least 650 gae/L, at least 660 gae/L. In
one preferred set of embodiments the loading of glyphosate is in
the range of from 600 to 750 gae/L particularly 600 to 700 gae/L
(or up to the limit of solubility).
[0014] The alkali metal hydroxide bases are in one set of
embodiments selected from at least one of sodium hydroxide,
potassium hydroxide and lithium hydroxide.
[0015] In a preferred set of embodiments the mixture of bases
includes at least one nitrogen base selected from the group
consisting of ammonia, mono-(C.sub.1 to C.sub.8) alkyl amines,
di-(C.sub.1 to C.sub.6) alkyl amines and tri-(C.sub.1 to C.sub.6
alkyl) amines and more preferably from the group consisting of
potassium hydroxide, ammonia, mono-(C.sub.1 to C.sub.6) alkyl
amines, di-(C.sub.1 to C.sub.6) alkyl amines and tri-(C.sub.1 to
C.sub.6 alkyl) amines.
[0016] In one set of embodiments when the mixture of bases includes
potassium hydroxide and one of ammonia or isopropylamine then at
least one further base selected from said alkali metal hydroxide
and said nitrogen base is present.
[0017] In a further set of embodiments the mixture of bases
includes a first alkali metal hydroxide selected from sodium
hydroxide, potassium hydroxide and lithium hydroxide and a second
alkali metal hydroxide selected from sodium hydroxide, potassium
hydroxide and lithium hydroxide.
[0018] Throughout the description and the claims of this
specification the word "comprise" and variations of the word, such
as "comprising" and "comprises" is not intended to exclude other
additives, components, integers or steps.
[0019] In the specification and claims the terms "ae", "gae" and
"kgae" in relation to glyphosate and its salts refer to acid
equivalent, grams of acid equivalent and kilograms of acid
equivalent respectively. The term gae/L means grams of acid
equivalent of the herbicide per liter of composition.
DETAILED DESCRIPTION
[0020] The method comprises forming a mixture, i.e. a premix, of at
least one alkali metal hydroxide and at least one further base
selected from alkali metal hydroxides and nitrogen bases, and
reacting the base premix with glyphosate acid.
[0021] The alkali metal hydroxides preferably include at least one
selected from the group consisting of sodium hydroxide and
potassium hydroxide.
[0022] The nitrogen bases may be selected from a range of compounds
such as those of formula I:
##STR00001##
wherein:
[0023] R.sup.1 is selected from the group consisting of hydrogen,
C.sub.1 to C.sub.10 alkyl, C.sub.1 to C.sub.10 alkanol and C.sub.1
to C.sub.10 amino alkyl;
[0024] R.sup.2 and R.sup.3 are independently selected from the
group consisting of hydrogen, C.sub.1 to C.sub.6 alkyl, C.sub.1 to
C.sub.6 alkanol, C.sub.1 to C.sub.6 amino alkyl and the group
wherein R.sup.2 and R.sup.3 together complete a 5 or 6 numbered
heterocyclic ring containing the nitrogen in formula I and
optionally a further heteroatom selected from 0 and N as a ring
member and optionally substituted by C.sub.1 to C.sub.6 alkyl.
Examples of compounds of formula I in which R2 and R3 complete a
heterocyclic ring include pirerazine, morpholine and the N-alkyl
derivatives thereof.
[0025] At least one nitrogen bases is preferably present and
includes at least one selected from the group consisting of
ammonia, C.sub.1 to C.sub.10 alkylamine, di-(C.sub.1 to C.sub.6
alkyl)amine, tri-(C.sub.1 to C.sub.6 alkyl)amine, C.sub.1 to
C.sub.10 alkanolamine C.sub.1 to C.sub.6 alkyl(C.sub.1 to C.sub.6
alkanol)amines and di-(C.sub.1 to C.sub.6 alkyl)(C.sub.1 to C.sub.6
alkanol)amines.
[0026] The nitrogen bases, in one set of embodiments contains at
least one selected from the group consisting of ammonia, C.sub.1 to
C.sub.10 alkylamine, di-(C.sub.1 to C.sub.4 alkyl)amine,
tri-(C.sub.1 to C.sub.4 alkyl)amine, C.sub.1 to C.sub.10
alkanolamine C.sub.1 to C.sub.4 alkyl(C.sub.1 to C.sub.4
alkanol)amines and di-(C.sub.1 to C.sub.4 alkyl)(C.sub.1 to C.sub.4
alkanol)amines.
[0027] Specific examples of readily available nitrogen bases
include those selected from the group consisting of ammonia,
methylamine, dimethylamine, trimethylamine, ethylamine,
diethylamine, triethylamine, propylamine, dipropylamine,
tripropylamine, isopropylamine, diisopropylamine, butylamine,
dibutylamine, tributylamine, isobutylamine, diisobutylamine,
triisobutylamine, 1-methylpropylamine (D, L),
bis(1-methyl)propylamine (D,L), 1,1-dimethylethylamine,
pentylamine, dipentylamine, tripentylamine, 2-pentylamine,
3-pentylamine, 2-methylbutylamine, 3-methylbutylamine,
bis(3-methylbutyl)amine and tris(3-methylbutyl)amine.
[0028] Specific examples of the preferred nitrogen bases may be
selected from the group consisting of ammonia, methylamine,
isopropylamine, dimethylamine, diethylamine, diisopropylamine,
triethylamine, triisopropylamine and dimethylethanolamine.
[0029] It is preferred that at least one nitrogen base is present
in the premix and is a non-oxygen containing base such as those
bases composed of nitrogen and at least one of nitrogen and
hydrogen. Thus it is preferred at least one base of the premix is
selected from the group consisting of ammonia, C.sub.1 to C.sub.10
alkylamine, di-(C.sub.1 to C.sub.4 alkyl)amine and tri-(C.sub.1 to
C.sub.4 alkyl)amine. Specific examples of such bases include
ammonia, methylamine, isopropylamine, dimethylamine, diethylamine,
diisopropylamine, trimethylamine triethylamine,
triisopropylamine)
[0030] In one set of embodiments the mixture of bases include at
least one base other than ammonia and isopropylamine.
[0031] The mixture of the bases will preferably comprise at least
3% (preferably at least 5% and more preferably at least 10%) by
weight of each of at least two bases. Further bases may be present
in smaller amounts or in amounts in this range of 5% to 95% by
weight if desired. In one embodiment there is an alkali metal
hydroxide selected from potassium hydroxide and sodium hydroxide
and a nitrogen base in a weight ratio in the range of from 10:90 to
90:10 such as from 20:80 to 80:20.
[0032] Some of the amines are volatile and in these circumstances
it may be preferred to introduce the volatile amine to a less
volatile amine or to form a mixture of amines in a suitable
solvent. In this embodiment the efficiency of the method is
generally significantly improved when compared with conventional
processes as the loss of volatiles is significantly reduced thereby
reducing costs and the problem of volatile emissions which are
particularly problematic in industrial scale exothermic reactions
such as the reaction of bases with glyphosate. Volatility is a
potential issue in exothermic conditions for amines of boiling
point up to 80.degree. C. and in particular up to 60.degree. C.
such as up to 50.degree. C. or up to 40.degree. C. In the case of
bases which are gaseous at room temperature such as ammonia and
methylamine dissolution in a liquid nitrogen base optionally in the
presence of a diluent such as water can improve significantly the
efficiency with which the bases react with glyphosate acid.
[0033] The mixture of at least two bases including an alkali metal
hydroxide and a further base selected from alkali metal hydroxides
and nitrogen bases forms a premix composition, that is a mixture
composition formed before mixing with the glyphosate acid. The
premix is preferably a homogeneous mixture of the bases when it is
added to the glyphosate acid.
[0034] Further bases and/or nitrogen containing adjuvants may be
added to the compositions before or following the combination of
the premix and glyphosate acid however the stoichiometry is
preferably controlled to provide reaction of the base premix with
at least the 50%, more preferably at least 80% and most preferably
at least 90% of the glyphosate acid.
[0035] The glyphosate acid composition which is combined with the
base premix may be in the form of a solid or may comprise a liquid.
In one set of embodiments the glyphosate is a neat dry solid when
combined with the base premix. In one embodiment the glyphosate
acid is in the form of a solution in a suitable solvent for the
glyphosate acid.
[0036] In one preferred set of embodiments the glyphosate acid
composition combined with the nitrogen base premix comprises water.
Glyphosate acid is conveniently manufactured in the form of a
wetcake comprising glyphosate acid and residual water from the
manufacturing process. The glyphosate acid used in the method may
be the wetcake containing glyphosate. Typically the wetcake
composition comprises, for example, at least 50% glyphosate such as
at least 60%, at least 70% or at least 80% glyphosate. In one
embodiment the glyphosate is in the form of a slurry containing
glyphosate acid in particulate form and sufficient water to
facilitate mixing and promote efficient reaction on combination
with the base premix.
[0037] The method may involve addition of the base premix to
glyphosate or addition of glyphosate to the premix. The two
compositions, the base premix and glyphosate acid composition may
also be simultaneously introduced to a reaction vessel. Generally
addition of the base premix to glyphosate is preferred.
[0038] In a preferred set of embodiments the bases are added to the
glyphosate acid aqueous composition in a mole ratio of total
bases:glyphosate acid in the range of from 0.9 to 1.3, preferably
0.9 to 1.2, more preferably 0.9 to 1.13 and still more preferably
1.0 to 1.1.
[0039] The reaction between the glyphosate acid and the bases may
be carried out at a range of temperatures such as from 5.degree. C.
to 90.degree. C. and preferably from 5.degree. C. to 60.degree.
C.
[0040] The mixture of bases may be added in a single addition,
stepwise and may be added quickly or over a period of time. In some
cases, particularly if the glyphosate is neat or in very
concentrated suspension, there may be a significant exothermic
reaction so that it may be appropriate to add the bases more slowly
or to cool the reaction mixture. The composition of the mixture of
bases may comprise a carrier such as water or other suitable liquid
carrier to improve or vary the miscibility of the different bases.
The presence of a carrier may also be used to dilute the bases and
regulate the rate of addition and/or the homogeneity of mixing with
the glyphosate acid.
[0041] The composition and method may utilize more than two bases
such as three, four or five bases but typically the use of two or
three bases is convenient. When used the further bases in addition
to the two bases may be nitrogen bases and/or non-nitrogen bases
such as alkali metal hydroxide or other metal bases.
[0042] On completion of the reaction the composition is a solution
of the glyphosate in the form of a mixture of salts having a
mixture of amine and alkali metal bases in the form of counter
ions, which are generally cations, following neutralization of the
glyphosate acid.
[0043] In general we have found that the viscosity of the aqueous
glyphosate composition prepared by the process involving mixing the
bases prior to reaction with glyphosate acid has a significantly
lower viscosity than the corresponding composition formed by
reacting each of the bases in sequence with glyphosate acid or from
mixing the glyphosate salts formed with the corresponding counter
ions provided by neutralization of glyphosate with the bases. The
method also allows base combinations to be prepared which would not
otherwise be available, for example because of high viscosity or
poor stability, if bases were added sequentially rather than as a
premix.
[0044] The composition is prepared by mixing the composition
comprising the mixture bases with glyphosate acid. Generally the
glyphosate acid will be present as a suspension or solid such as a
precipitate in an aqueous composition. The concentration of the
glyphosate acid will typically be at least 600 gae per liter of
aqueous composition. The concentration of the glyphosate acid is
preferably at least 610 gae/L preferably at least 620 gae/L, more
preferably at least 630 gae/L and still more preferably at least
640 gae/L and most preferably at least 650 gae/L such as at least
650 gae/L, at least 700 gae/L, at least 750 gae/L and up to the
limit of solubility. The optimum concentration of the acid
composition will of course depend on the nature of the bases, their
concentration and reaction conditions.
[0045] The method provides a significant advantage in the transport
and handling of glyphosate concentrate. The ability to reduce
significantly the viscosity of concentrates of a given loading or
increase loading without the normal substantial increase in
viscosity and consequential problems of instability and handling
has significant economic benefits for the manufacturer and farmer.
The cost of transport of a given active glyphosate quantity can be
reduced and/or more economic pumping or dispensing equipment can be
used. Accordingly, in one set of embodiments there is provided a
method as hereinbefore described and further comprising loading the
aqueous mixture of glyphosate salts into containers of volume in
the range of 0.1 to 10,000 liters to substantially fill the
containers, transporting the filled containers and dispensing the
aqueous mixture of glyphosate salts from the containers. The
aqueous mixture of glyphosate salts is preferably pumped into the
containers.
[0046] The glyphosate concentrate may and preferably will comprise
a surfactant. When used the surfactant component may be added at
any time during the preparation process for example it may be
present in the base mixture composition, in the glyphosate acid
aqueous composition or may be added during and/or after reaction of
the glyphosate acid with the mixture of amines.
[0047] The appropriate method will depend on the chemical nature of
the surfactant and base reagents. For example, the caustic nature
of alkali metal hydroxides generally means that addition with the
base is undesirable particularly where such components react with
or are decomposed by alkaline conditions.
[0048] The method may be used in preparing glyphosate compositions
containing adjuvants and co-solvents, such as surfactants,
antifoaming agents, glycols, stickers, penetrants drift reduction
agents and water conditioners such as those selected from the group
consisting of pH adjusters, buffering agents & AMADS
(monocarbamide dihydrogen sulfate i.e. urea+sulfuric acid),
isethonic acid and sulphated glycerine, and the like.
[0049] The method may also be used in preparation of concentrates
to which such adjuvants may be added during tank mixing.
[0050] Thus, in one set of embodiments there is provided a kit for
controlling plant growth comprising a first part comprising the
concentrate composition prepared by the method hereinbefore
described and a second part comprising an adjuvant composition for
mixing with the concentrate on dilution with water such as in a
spray tank prior to application to plants to be controlled.
[0051] The dilute compositions for application to plants whose
growth is to be controlled may be prepared on site by the end-user
shortly before application to the foliage of vegetation to be
controlled, by mixing in the glyphosate concentrate prepared in
accordance with the above method with an aqueous diluent. The
aqueous diluent may further comprise a surfactant such as one or
more of those described above. Such compositions are generally
referred to as "tank-mix" compositions.
[0052] In the case of a solution concentrate adapted for simple
dilution prior to application the composition will preferably
comprise a surfactant. In this set of embodiments the concentration
of the surfactant may be up to 30% by weight (preferably up to 25%
by weight) of the aqueous composition. The range of surfactant
concentrations may, for example be in the range of from 0.1 to 20%
by weight of the aqueous composition and more preferably from 1 to
15% by weight of the aqueous composition.
[0053] The concentration of the surfactant may be up to 30% by
weight of the aqueous composition preferably in the range of from
0.1 to 30% by weight of the aqueous composition and more preferably
from 1 to 25% by weight of the aqueous composition. In one set of
embodiments the total surfactant is present in an amount of no more
than 20% by weight of the total aqueous glyphosate concentrate.
[0054] Amphiphilic agents which have been claimed to enhance the
herbicidal efficacy of formulations comprising glyphosate salts
include the following: quaternary ammonium surfactant; etheramine
surfactants; alkylether and amine surfactant combinations;
acetylenic diol and alkyl(poly)glycoside surfactant combinations;
lipophilic fatty amine ethoxylate surfactants; alkoxylated amine
surfactants; betaine surfactants; alkyl polyglycoside agents;
secondary or tertiary alcohol surfactants; silicone copolymer
wetting agents and trialkylamine oxide or quaternary amine or
trialkylbetaine surfactant combinations; sorbitan fatty acid ester
and amine, quaternary ammonium or alkylglycoside surfactant
combinations; surfactants derived from alkanethiols;
polyoxyalkylene trisiloxane surfactants; super-wetting agents such
as silicone-based and fluorocarbon-based surfactants;
supra-molecular aggregates comprising one or more amphiphilic salts
having a glyphosate anion and cation derived by protonation of
secondary or tertiary oily amines; alkoxylated primary alcohol
surfactants; alkyl polysaccharide derivates; alkyl polyglycoside
and ethoxylated alcohol combinations; alkylglucosides; surfactants
comprising polyhydroxyhydrocarbyl and amine functionality;
alkylglycoside and alkoxylated alkylamine surfactant combinations;
alkyldiamine tetraalkoxylate surfactants; succinic acid
derivatives; alkoxylated amido amines; sugar glycerides such as
rapeseed oil sugar glyceride; diamine surfactants; widely-bridged
alcohol polyethoxylates; water-soluble long-chain hydrocarbyl
dimethylamine oxides and quaternary ammonium halide combinations;
hydroxyalkylammonium adjuvants; polyether diamine surfactants;
cationic, anionic, nonionic or zwitterionic silicone adjuvants;
organosilicone surfactants and diphenyl oxide sulfonate surfactant
combinations; a range of ether phosphate adjuvants; phosphourous
surfactant adjuvants; polyglycerol and polyglycerol derivatives;
C.sub.8-C.sub.22 sarcosinate or sarcosinate salts; ethoxylated
vegetable oils; polyethoxylated dialkylamine surfactants;
C.sub.10-C.sub.18 alkylpolyglycol ether sulfates; Sucrose &
Sorbital Surfactants; Sorbitan Esters; Ethoxylated Saccahrose
Esters; Coco Amido Propyl Dimethylamine Akyldimethylamines;
Phosphated Esters Tallow Amine Surfactants; Trisiloxanes; TEA and
MDEA Esterquats; Dimethylethanolamine based Esterquats; Saccharides
such as Alkyl Polysaccharide as well a glucosides; Alkyl
Polypentosides (APP); Polyglycerines; Etheramine Alkoxylates;
Sorbitan Monolaurate; Pine Terpinic compounds such oligomers etc
(derived from alpha pinene & beta pinene)/Pine Oils; Cocoamine
ethoxylates; Acrylates & Latex compounds; (Ethoxylated)Oleyl
Alcohols; Alkylamine Alkoxylates; Etheramine Alkoxylates/Alkyl
Etheramine; Quaternary Ammonium Salts/Ammonium Quaternary
Derivatives; Quat Amines; Amine Oxides; Dialkoxylates Amines; Alkyl
Alkoxylated Phosphates; Aminated Alkoxylated Alcohols;
Dialkoxylated Amines; Carboxylates; Alkylethersulfates; Disodium
sulfosuccinates/Succinates; Polyether Amines; Cocoamidopropyl
betaines and salts of fatty acids.
[0055] Etheramine surfactants include surfactants having the
representative chemical structure (a):
##STR00002##
wherein R.sub.1 is a straight or branched chain C.sub.6 to about
C.sub.22 alkyl, aryl or alkylaryl group, m is an average number
from 1 to about 10, R.sub.2 in each of the m (O--R.sub.2) groups is
independently C.sub.1-C.sub.4 alkylene, R.sub.3 groups are
independently C.sub.1-C.sub.4 alkylene, and x and y are average
numbers such that x+y is in the range from 2 to about 60; or
(b):
##STR00003##
wherein R.sub.1 is a straight or branched chain C.sub.6 to about
C.sub.22 alkyl, aryl or alkylaryl group, m is an average number
from 1 to about 10, R.sub.2 in each of the m (O--R.sub.2) groups is
independently C.sub.1-C.sub.4 alkylene, R.sub.3 groups are
independently C.sub.1-C.sub.4 alkylene, R.sub.4 is C.sub.1-C.sub.4
alkyl, x and y are average numbers such that x+y is in the range
from 0 to about 60 and A.sup.- is an agriculturally acceptable
anion; or (c)
##STR00004##
wherein R.sub.1 is a straight or branched chain C.sub.6 to about
C.sub.22 alkyl, aryl or alkylaryl group, m is an average number
from 1 to about 10, R.sub.2 in each of the m (O--R.sub.2) groups is
independently C.sub.1-C.sub.4 alkylene, R.sub.3 groups are
independently C.sub.1-C.sub.4 alkylene and x and y are average
numbers such that x+y is in the range from 2 to about 60.
[0056] In one set of embodiments the glyphosate composition
prepared by the method is substantially free of surfactants, prior
to use, for example, when the concentrate is diluted with water in
a spray tank prior to use.
[0057] In a further set of embodiments we provide a method for
controlling plant growth comprising diluting the concentrate with
water, optionally with addition of adjuvant, and applying the
glyphosate to plants by, for example spray or application via a
substrate on which the diluted composition is sorbed.
[0058] In a further set of embodiments the concentrate is applied
without dilution by for example painting or contacting plants with
a substrate such as a rope or wick on which the concentrate is
absorbed.
[0059] One of the important advantages of the glyphosate
compositions prepared according to the method is that the
glyphosate concentration can be increased to very high levels, for
example even over 600 gae/L, yet the surfactant concentration may
still be included in a concentrate adequate to give excellent
herbicidal performance without the end-user requiring to add more
surfactant in the spray tank. In many cases the compositions
prepared by the methods allow incorporation of surfactant which
would not otherwise be possible for corresponding compositions
prepared by combination of preformed salts or compositions prepared
by sequential neutralization of glyphosate acid with different
bases. In other cases the compositions prepared by the method
provides handling characteristics such as pourability and pumping
performance superior to the corresponding compositions prepared by
combination of preformed salts or compositions prepared by
sequential neutralization of glyphosate acid with different bases.
The aqueous concentrates also generally have remarkably good
storage stability under a wide range of temperature conditions
despite the high loading of glyphosate and are generally superior
to corresponding compositions prepared by combination of preformed
salts of monobases (i.e. a glyphosate salt prepared using a single
base in a separate vessel) or compositions prepared by sequential
neutralization of glyphosate acid with different bases.
[0060] Mixtures of glyphosate with other herbicides may also be
prepared from the concentrated prepared by the method described
above. Examples of such other herbicides include glufosinate,
2,4-D, MCPA, dicamba, diclorprop, diphenylethers, imidazolinones,
sulfonylureas, other herbicides, insecticides, plant growth
regulators and fungicides
[0061] In one embodiment the method further comprises forming a
mixture of at least one further acid herbicide with glyphosate acid
and reacting the mixture of the at least two bases with the mixture
of glyphosate acid and at least one other acid herbicide to provide
a composition comprising a mixture of glyphosate salts and a
mixture of salts of said at least one further herbicidal acid. The
further acid herbicide will preferably comprise at least one acid
group selected from phosphonic acid, sulfonic acid and carboxylic
acid and preferably at least one carboxylic acid group.
[0062] The at least one further herbicidal acid may be selected
from the group consisting of: [0063] (i) benzoic acid herbicides
such as acifluorfen chloramben; dicamba; 2,3,6-TBA; tricamba;
[0064] (ii) pyrimidinyloxybenzoic acid herbicides such as
bispyribac and pyriminobac; pyrimidinylthio-benzoic acid herbicides
such as pyrithiobac; [0065] (iii) picolinic acid herbicides such as
aminopyralid, clopyralid and picloram; [0066] (iv)
quinolinecarboxylic acid herbicides such as quinclorac and
quinmerac; [0067] (v) phenoxy acid herbicides such as 4-CPA, 2,4-D,
3,4-DA, MCPA and 2,4,5-T; [0068] (vi) phenoxybutyric herbicides
such as 4-CPB, 2,4-DB, 3,4-DB, MCPB and 2,4,5-TB; [0069] (vii)
phenoxypropionic herbicides such as cloprop, 4-CPP, dichlorprop,
dechlorprop-P, fenoprop, mecoprop, mecoprop-P; [0070] (viii) acid
substituted diphenyl ether herbicide such as ethoxyfen; [0071] (ix)
aryloxy phonoxypropionic acid herbicides such as chlorazifop,
clodinafop, clofop, flueroglycofen, cyhalofop, diclopfop,
fenoxaprop, fenoxaprop-P, fenthiaprop, fluazifop, fheazifoop-P,
haloxyfop, haloxyfop-P, isoxapyrifop, metamifop, propaquizafop,
quizalofop, quizalofop-P and trifop; [0072] (x) herbicides such as
benzoylprop, aryalamine, flamprop and flamprop-M; [0073] (xi) acid
substituted nitro phenyl ether herbicides such as acifluorfen; and
[0074] (xii) organophosphorous herbicides other than glyphosate
such as glufosinate and glufosinate-P
[0075] The more preferred acid herbicides for use in the invention
are selected from the group consisting of dicamba, aminopyralid,
clopyralid, picloram, 2,4-D, MCPA, 2,4-DB, mecaprop, mecoprop-P,
glufosinate, diclofop and fluazifop. Still more preferably, the one
or more further acid herbicides when used with glyphosate acid are
selected from the group consisting of dicamba, clopyralid, 2,4-D,
MCPA and mecoprop.
[0076] Where there are a mixture of acid herbicides it is preferred
that the glyphosate concentration in the final concentrate is at
least 200 gae/L (preferably at least 360 gae/L, more preferably at
least 450 gae/L) and the total acid herbicide salt in the final
concentrate composition is at least 360 gae/L, more preferably at
least 450 gae/L, still more preferably at least 550 gae/L and most
preferably at least 600 gae/L.
[0077] When further acid herbicides are used in the process of the
invention the glyphosate will typically comprise at least 20% by
weight based on acid equivalent of the total acid herbicides
preferably glyphosate acid will constitute at least 40% by weight,
still more preferably at least 60% by weight and most preferably at
least 80% by weight of the total acid herbicides including
glyphosate.
[0078] In one embodiment, the glyphosate acid constitutes at least
95% more preferably at least 98% of the total acid herbicides
(including glyphosate).
[0079] In a further embodiment, the glyphosate composition mixed
with the mixture of at least two bases is free of other herbicidal
acids.
[0080] In the embodiments in which a mixture of acid herbicides
including glyphosate are reacted with the mixture of at least two
bases it is preferred that the molar ratio of total alkali metal
hydroxides and nitrogen bases:total acid herbicides is in the range
of 0.9:1 to 1.3:1.
[0081] Methods of use of glyphosate formulations are well known to
those of skill in the art. Aqueous concentrate compositions
prepared by the method may be diluted in an appropriate volume of
water and applied, for example by spraying, to unwanted vegetation
to be controlled. Compositions prepared by the method may be
applied at glyphosate ae rates in the range of for example from
about 0.1 to about 5 kgae/ha, occasionally more. Typical glyphosate
ae rates for control of annual and perennial grasses and
broadleaves are in the range from about 0.25 to about 3 kgae/ha.
Compositions of the invention may be applied in any convenient
volume of water, most typically in the range from about 30 to about
2000 l/ha. Compositions prepared by the method of the invention
also include solutions which may be applied by spraying for
example. In these solutions, the concentration of glyphosate is
selected according to the volume per unit area of spray solution to
be used and the desired rate of application of glyphosate per unit
area. For example, conventional spraying is done at 30 to 2000
liters (particularly 50-600 liters) of spray solution per hectare,
and the rate of application of glyphosate is typically 0.125 to 1.5
kg of glyphosate acid equivalent per hectare. Spray solution
compositions can be prepared by diluting the aqueous liquid
concentrates preferably comprising surfactant adjuvants or by tank
mixing the aqueous concentrates formed by the method with adjuvants
as described above.
[0082] The invention will now be described with reference to the
following examples. It is to be understood that the examples are
provided by way of illustration of the invention and that they are
in no way limiting to the scope of the invention.
EXAMPLES
[0083] Compositions of glyphosate salts were prepared from
glyphosate acid using the bases identified in Table 1 added in
accordance with (A) comparative process in which bases were reacted
with glyphosate acid by "separate" addition of the bases in
sequence and (B) a process in accordance with the invention in
which the bases were "mixed" and the mixture of bases added to an
aqueous slurry of glyphosate acid.
[0084] (A) In the "separate" addition process the bases identified
in the table were separately added in sequence in the molar base
ratio identified the Table 1 to an aqueous slurry of glyphosate
acid in an amount to neutralise the glyphosate acid. Where
indicated in the table a surfactant was used and was added to the
composition following neutralisation of the glyphosate acid. The
final composition had a glyphosate concentration based on
glyphosate acid equivalent indicated in the table expressed in
grams of glyphosate acid equivalent per liter of composition (gae/L
Glyphosate Acid).
[0085] (B) In the mixed addition process the bases shown in Table 1
were mixed in the molar ratios indicated and were added to an
aqueous slurry of glyphosate acid in an amount to neutralise the
glyphosate acid (equimolar amount). Where indicated in the table a
surfactant was used and was added to the composition following
neutralisation of the glyphosate acid. The final composition had a
glyphosate concentration based on glyphosate acid equivalent
indicated in the table expressed in grams of glyphosate acid
equivalent per liter of composition (gae/1 Glyphosate).
[0086] In Table 1 the following abbreviations are used for the
bases which are used to form glyphosate counter ions:
MMA--monomethylamine MIPA--monoisopropylamine NH3--ammonia
TEA--triethylamine KOH--potassium hydroxide NaOH--sodium hydroxide
MEA--monoethanolamine DMA--dimethylamine
Testing
[0087] Each of the compositions prepared by (A) the separate
addition of bases and (B) the mixed addition of bases were subject
to testing to determine the assay results reported in the table in
the following procedures:
[0088] In the Examples pH was determined by the method described in
CIPAC MT 75.3 at 5% w/V in deionised water. Viscosity was
determined at 5.degree. C. and at 20.degree. C.
[0089] The viscosity of compositions was measured after
equilibrating the composition at the respective temperatures using
a Brookfield viscometer (model DV-1) Spindle 21 in a fixed volume
temperature controlled cylinder to ensure direct comparability
TABLE-US-00001 TABLE 1 Viscosity Viscosity base gae/L Surfactant 5%
mPa s mPa s Ex base ratio process Glyphosate Surfactant g/L pH
5.degree. C. 20.degree. C. Ex1 MMA/MIPA/KOH 45/10/45 premix 650
None 0 4.5 312 143 CE1 MMA/MIPA/KOH 45/10/45 separate 650 None 0
4.49 328.4 147 Ex2 MMA/MIPA/KOH 50/20/30 premix 650 None 0 4.4
332.8 139.7 CE2 MMA/MIPA/KOH 50/20/30 separate 650 None 0 4.51
401.1 155.7 Ex3 MMA/MIPA/KOH 50/20/30 premix 570 Surf A 140 4.45
671.4 268 CE3 MMA/MIPA/KOH 50/20/30 separate 570 Surf A 140 4.55
837.9 282 Ex4 MEA/KOH 45/55 premix 650 None 0 4.54 411.2 154.9 CE4
MEA/KOH 45/55 separate 650 None 0 4.43 528.7 188.9 Ex5 MEA/KOH
45/55 premix 570 Surf A 140 4.59 361.3 198 CE5 MEA/KOH 45/55
separate 570 Surf A 140 4.49 401.1 212 Ex6 MMA/KOH 55/45 premix 723
None 0 4.45 510.2 187 CE6 MMA/KOH 55/45 separate 723 None 0 4.45
538.3 199 Ex7 MMA/KOH 55/45 premix 650 None 0 4.47 213.1 97.2 CE7
MMA/KOH 55/45 separate 650 None 0 4.42 229 108 Ex8 MMA/KOH 55/45
premix 650 Surf B 100 4.51 503.4 76 CE8 MMA/KOH 55/45 separate 650
Surf B 100 4.41 568.1 197 Ex9 NaOH/KOH 15/85 premix 650 None 0 4.46
138.2 60.1 CE9 NaOH/KOH 15/85 separate 650 None 0 4.40 140.5 61.8
Ex10 NaOH/KOH 15/85 premix 650 Surf B 200 4.54 814 249 CE10
NaOH/KOH 15/85 separate 650 Surf B 200 4.45 861 256
Surf. A Quaternary amine surfactant Surf. B Tallow amine surfactant
blend
Example 11 and Comparative Example 11
Monobasic Glyphosate Combinations Compared with Base Premix
[0090] The mixed salt batch of Example 11 was prepared by reacting
a premix of MEA and KOH in the ratio shown in Table 2 with
glyphosate acid to provide mixed glyphosate salts in the final
concentrate with a concentration of 600 gae/L.
[0091] The mixed salt batch CE11 was made by adding (a) the
monoethanolamine salt of glyphosate and (b) the potassium salt of
glyphosate monobase batches together in the ratios shown below in
Table 2 and mixed for 20 minutes before testing. The monobases were
prepared by:
(a) using MEA to neutralize glyphosate acid at 600 g/L (84.6%
glyphosate wet cake), and (b) using KOH to neutralize glyphosate
600 g/L (84.6% glyphosate wet cake)
TABLE-US-00002 TABLE 2 glyph- Viscosity Viscosity osate Base mPa s
mPa s Ex gae/L ratio Bases Process 5.degree. C. 20.degree. C. CE11
600 55/45 MEA/KOH mono- 226 89.8 (a)/(b) base Ex11 600 55/45
MEA/KOH premix 76.4 36.3
[0092] Table 2 shows that the viscosity of the composition
resulting from reacting a base premix is significantly less
notwithstanding that the composition of the final concentrate
equivalent.
Example 12 and Comparative Example 12
[0093] This example demonstrates preparation of a mixture of salts
from glyphosate acid in the presence of a further acid herbicide,
dicamba.
[0094] Example 12 was prepared in accordance with the invention by
forming a premix of bases shown in Table 3 in the molar ratios
listed and reacting the premix with a mixture of glyphosate acid
and dicamba acid to provide the concentration gae/L of mixed salts
of glyphosate and mixed salts of dicamba shown.
[0095] The process of CE 12 was to individually prepare (a)
potassium salt of a mixture of glyphosate and dicamba and (b)
monoethanolamine salt of a mixture of glyphosate and dicamba and
combine the two salt compositions to provide a mixture of potassium
and monoethanolamine salts of both glyphosate and dicamba in the
concentration in the final concentrate composition as shown in
gae/L.
TABLE-US-00003 TABLE 3 Example gae/L gae/L Base Base Viscosity
Viscosity No. Glyphosate Dicamba Mixing Bases Ratio 5.degree. C. cp
20.degree. C. cp Appearance SG pH Ex 12 220 220 Premix KOH/MEA
50/50 32 17.2 Clear sol 1.286 8.85 CE12 220 220 Separate KOH/MEA
50/50 45.1 22 Clear sol 1.285 9
[0096] The concentrate prepared in accordance with the method of
the invention (Ex12) has a significantly lower viscosity than the
comparison (CE12) not withstanding that the compositions are
otherwise equivalent.
* * * * *