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Dokumentenidentifikation EP1313366 30.09.2004
EP-Veröffentlichungsnummer 0001313366
Titel KONTINUIERLICHES VERFAHREN ZUR HERSTELLUNG VON EINEM HERBIZIDEN WÄSSRIGEM SUSPENSIONSKONZENTRAT
Anmelder BASF AG, 67063 Ludwigshafen, DE
Erfinder FAFCHAMPS, Jean-Paul, F-59380 Quaedypre, FR;
VILLANUEVA, Jean-Michel, F-06250 Mougins, FR
DE-Aktenzeichen 60105174
Vertragsstaaten AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LI, LU, MC, NL, PT, SE, TR
Sprache des Dokument EN
EP-Anmeldetag 24.08.2001
EP-Aktenzeichen 019696400
WO-Anmeldetag 24.08.2001
PCT-Aktenzeichen PCT/EP01/09787
WO-Veröffentlichungsnummer 0002015690
WO-Veröffentlichungsdatum 28.02.2002
EP-Offenlegungsdatum 28.05.2003
EP date of grant 25.08.2004
Veröffentlichungstag im Patentblatt 30.09.2004
IPC-Hauptklasse A01N 33/18

Beschreibung[en]
BACKGROUND OF THE INVENTION

Stable aqueous suspension concentrate compositions of pendimethalin, alone or in combination with a secondary herbicide, and methods for their preparation are described in US 5,624,884. However, the methods so described are 2-step methods wherein the first step is the formation of a hot aqueous emulsion of molten pendimethalin and the second step is the cooling of said emulsion to crystallize the pendimethalin and form an aqueous suspension concentrate. Optionally, a third milling step may be added. The discreet steps of forming a hot emulsion, then cooling said emulsion and optionally milling said cooled emulsion, entail a non-integrated batch procedure. That is, the desired product must be produced in discreet batches of a fixed quantity and the process must begin, end and start again, repeatedly. Such batch processes, when producing quantities at a manufacturing scale can be time-consuming, and labor and energy intensive.

Therefore, it is an object of this invention to provide a Single-step continuous process suitable for the preparation of a stable herbicidal aqueous suspension concentrate composition at a manufacturing scale.

It is an advantage of this invention that said stable herbicidal compositions may be prepared efficently and effectively with reduced time, labor and energy resources.

SUMMARY OF THE INVENTION

The present invention provides a process for the preparation of an aqueous suspension concentrate composition which comprises mixing a molten pendimethalin stream having a temperature of 57° to 75°C with an aqueous stream containing coformulants plus seed crystals of orange pendimethalin said aqueous stream having a temperature of -3°C to 5°C.

DETAILED DESCRIPTION OF THE INVENTION

Pendimethalin is a low-melting dinitroaniline herbicide useful in agricultural, horticultural and turf applications. In its solid form, pendimethalin exists primarily in two polymorphic forms, generally referred to as the orange form and the yellow form. It is known that compositions containing crystalline pendimethalin in 100% of the orange form or in a ratio of 96:4 of the orange form to the yellow form demonstrate enhanced stability. However, control of the poylmorph ratio of pendimethalin in a process involving the conversion of molten pendimethalin to solid pendimethalin is known to be difficult. US 5,624,884 describes stable aqueous suspension concentrate compositions of pendimethalin and methods for their preparation. However, said methods require a two-step procedure which necessitates a batch production effort.

Surprisingly it has now been found that a stable aqueous suspension concentrate composition of pendimethalin may be prepared in a continuous Single-step procedure which comprises the high shear mixing of a molten pendimethalin stream, having a temperature of 57° to 75°C, with an aqueous stream containing coformulants plus seed crystals of orange pendimethalin, said aqueous stream having a temperature of -3°C to 5°C. Advantageously, the process of the invention instantaneously and continuously generates a cool stable aqueous suspension of fine, regular, orange crystals of pendimethalin. The process of the invention may be run continuously by any conventional means such as an in-line high shear disperser/homogenizer. Alternatively, the process may be run in batch fashion, if so desired. The stable herbicidal aqueous suspension concentrate composition produced by the process of the invention may optionally be milled to obtain an average particle size of suspended particles of less than 5-20 microns.

The process of the invention may also be used to prepare stable aqueous suspension concentrate compositions containing pendimethalin in combination with one or more pesticides which are low-melting or watersoluble. For example, an additional water-soluble pesticide may be included in the cooled aqueous stream, prior to the mixing of the two streams.

Compositions produced by the process of the invention typically comprise on a weight to volume basis, 5.0% to 50.0% pendimethalin; 0% to 50.0% of one or more additional pesticides which are water soluble; 3.0% to 30.0% of coformulants, such as surfactants, dispersing agents, wetting agents, antifreeze agents, antifoam agents, suspending agents, thickeners, preservatives, and 20.0% to 92.0% water.

As used in the specification and claims, the term coformulant designates an ingredient such as: a watersoluble pesticide, i.e. a herbicide, fungicide, insecticide, plant growth regulant, an antifreeze agent, i.e. ethylene glycol, propylene glycol, glycerine, urea, an antifoam agent, i.e. silicon, a suspending agent, i.e. silica, MgS04, a thickener, i.e. clay, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, a preservative,i.e. formaldehyde, methyl or propyl parahydroxybenzoate, sodium benzoate, a surfactant such as a dispersing agent, a wetting agent or any standard inert ingredient conventionally used in agricultural suspension concentrate compositions.

Water-soluble pesticides contemplated for use in the process of the invention include herbicides, for example: quaternary salts of amino phosphonic or phosphinic acids such as glyphosate, glufosinate, substituted phenoxy or benzoic acid salts such as 2,4-D, 2,4-DB, MCPP, MCPA, dicamba, chloramben, imidazolinones such as imazaquin, imazethapyr, imazamox, imazapic, imazapyr, or any of the known water-soluble herbicidal agents which possess physical/chemical properties known to be amenable to the preparation of aqueous suspension concentrate compositions. Fungicides, insecticides or plant growth regulants which are water-soluble and possess physical/chemical properties which are amenable to the preparation of aqueous suspension concentrate compositions are also contemplated.

Surfactants (including dispersing agents and wetting agents) suitable for use as a coformulant in the process of the invention include: ethylene oxide/propylene oxide condensates; alkylarylor arylarylethoxylates or derivatives thereof; lignosulfonates; cresol- or naphthalene-formaldehyde condensates or the sulfonates thereof; polycarboxylates or derivatives thereof; or mixtures thereof. Preferred surfactants are: anionic polymerics, such as mixtures of alkylaryl- or arylarylethoxylates or their derivatives; cresol formaldehyde condensates or their sulfonates; naphthalene formaldehyde condensates or their sulfonates; or lignosulfonates. More preferred surfactants are mixtures of alkyl, aryl- and arylarylethoxylates or their derivatives.

Accordingiy, stable aqueous suspension concentrate compositions of pendimethalin may be prepared by highshear mixing of a stream of molten pendimethalin having a temperature of about 57° to 75°C with an aqueous stream containing co-formulants plus orange pendimethalin seed crystals said aqueous stream having a temperature of -3° to 5°C. In actual practice, a molten stream of technical pendimethalin at 57° to 75°C is continuously fed into a high-shear disperser/homogenizer simultaneously with an aqueous stream containing coformulants and 16-24% of orange pendimethalin seed crystals, the aqueous stream having been pre-cooled to temperatures of -3°C to 5°C to produce a continuous exit stream of a stable aqueous suspension concentrate composition of pendimethalin. By continuously, simultaneously feeding and mixing the molten pendimethalin and cooled aqueous streams in an in-line disperser/homogenizer while continuously discharging the resulting orange suspension concentrate composition, the process of the invention facilitates optimum production with significantly increased conservation of time, labor and energy resources. Optionally, the thus-produced suspension concentrate may be bead-milled at 20-29°C to achieve a particle size of less than 5-20µm.

Water-soluble pesticides may be co-formulated with pendimethalin using the process of the invention by dissolving said pesticide in the aqueous stream containing coformulants plus orange pendimethalin seed crystals prior to mixing with the molten pendimethalin stream.

Beneficially, compositions produced by the process of the invention do not form large, elongated crystals after being processed. Therefore, processing and manufacturing is not halted because of aggregation due to crystal growth. Further, the agronomic application and efficacy of the suspension concentrate product is not hampered nor compromised by uneven particle size, sedimentation, or crystal growth.

For a more clear understanding of the invention, the following examples are set forth below.

Unless otherwise noted, all parts are parts by weight.

Examples 1-7 Preparation of Stable Aqueous Suspension Concentrate Compositions of Pendimethalin

An aqueous stream containing coformulants and 16-24 % of orange crystalline pendimethanlin is pre-cooled to temperatures of -3°C to 5°C and mixed in a high-shear disperser/homogenizer with a stream of molton pendimethalin at temperatures of 57°C to 75°C to yield a concentrated aqueous suspension of orange crystalline pendimethalin.

Using the above procedure, the anqueous suspension concentrate compositions shown on Table I are obtained.


Anspruch[de]
  1. Verfahren zur Herstellung einer stabilen wäßrigen Suspensionskonzentratzusammensetzung, dadurch gekennzeichnet, daß man einen geschmolzenen Pendimethalin-Strom mit einer Temperatur von 57 bis 75°C mit einem wäßrigen Strom, der Formulierungshilfsmittel sowie orange Pendimethalin-Impfkristalle enthält, vermischt, wobei der wäßrige Strom eine Temperatur von -3°C bis 5°C aufweist.
  2. Verfahren nach Anspruch 1, wobei die Impfkristalle in einer Menge von 16% bis 24% vorliegen.
  3. Verfahren nach Anspruch 1, wobei die Formulierungshilfsmittel unter einem Tensid, einem Gefrierschutzmittel, einem Antischaummittel, einem Suspendiermittel, einem Verdickungsmittel, einem Konservierungsmittel, einem wasserlöslichen Pestizid und einer Mischung von diesen ausgewählt wird.
  4. Verfahren nach Anspruch 3, wobei das Tensid unter einem Ethylenoxid/Propylenoxid-Kondensat, einem Alkylaryl- oder Arylarylethoxylat, einem Ligninsulfonat, einem Kresol-Formaldehyd-Kondensat oder einem seiner Sulfonate, einem Naphthalin-Formaldehyd-Kondensat oder einem seiner Sulfonate, einem Polycarboxylat oder einem seiner Derivate und einer Mischung von diesen ausgewählt wird.
  5. Verfahren nach Anspruch 3, wobei das Tensid unter einem Alkylarylethoxylat, einem Polyarylarylethoxylatphosphat-Triethanolaminsalz oder -kaliumsalz, einer Polyarylarylpolyoxyethylenphosphorsäure, einem Natriumkresol-Formaldehyd-Kondensat, einem Natriumsalz eines sulfonierten Kresol-Formaldehyd-Kondensats und einer Mischung von diesen ausgewählt wird.
  6. Verfahren nach Anspruch 3, wobei das Gefrierschutzmittel unter Ethylenglykol, Propylenglykol, Glycerin, Harnstoff und einer Mischung von diesen ausgewählt wird.
  7. Verfahren nach Anspruch 3, wobei das Verdickungsmittel unter Ton, Fällungskieselsäure, Polyvinylalkohol, Polyvinylpyrrolidon, Polyacrylamid und einer Mischung von diesen ausgewählt wird.
  8. Verfahren nach Anspruch 3, wobei das Konservierungsmittel unter einer 38%igen Formaldehydlösung, Methyl- oder Propylparahydroxybenzoat, 2-Brom-2-nitropropan-1,3-diol, Natriumbenzoat, Glutaraldehyd, o-Phenylphenol, Benzisothiazolinon, Methyl- oder Ethyl-4-isothiazolin-3-on, Pentachlorphenol, 2,4-Dichlorbenzylalkohol und einer Mischung von diesen ausgewählt wird.
  9. Verfahren nach Anspruch 8, wobei es sich bei dem Konservierungsmittel um eine 38%ige Formaldehydlösung handelt.
  10. Verfahren nach Anspruch 3, wobei es sich bei dem wasserlöslichen Pestizid um ein wasserlösliches Herbizid handelt.
  11. Verfahren nach Anspruch 10, wobei das Herbizid unter einem quartären Salz einer Aminophosphonsäure oder Aminophosphinsäure, einem substituierten Phenoxy- oder Benzoesäuresalz, einem Imidazolinon oder einer Mischung von diesen ausgewählt wird.
  12. Verfahren nach Anspruch 11, wobei das Herbizid unter Glyphosat, Glufosinat, 2,4-D, MCPA, Dicamba, Imazaquin, Imazethapyr, Imazapic, Imazamox, Imazapyr und einer Mischung von diesen ausgewählt wird.
Anspruch[en]
  1. A process for the preparation of a stable aqueous suspension concentrate composition which comprises mixing a molten pendimethalin stream having a temperature of 57° to 75°C with an aqueous stream containing coformulants plus seed crystals of orange pendimethalin said aqueous stream having a temperature of -3°C to 5°C.
  2. The process according to claim 1, wherein said seed crystals are present at 16% to 24%.
  3. The process according to claim 1 wherein said coformulants are selected from the group consisting of a surfactant; an antifreeze agent; an antifoam agent; a suspending agent; a thickener; a preservative; a watersoluble pesticide; and a mixture thereof.
  4. The process according to Claim 3 wherein said surfactant is selected from the group consisting of an ethylene oxide/propylene oxide condensate; an alkylarylor arylarylethoxylate; a lignosulfonate; a cresolformaldehyde condensate or a sulfonate thereof; a naphthalene-formaldehyde condensate or a sulfonate thereof; a polycarboxylate or a derivative thereof; and a mixture thereof.
  5. The process according to claim 3 wherein the surfactant is selected from the group consisting of an alkylarylethoxylate; a triethanolamine salt or a potassium salt of polyarylarylethoxylate phosphate; a polyarylarylpolyoxyethylene phosphoric acid; a sodium cresol-formaldehyde condensate; a sodium salt of a sulfonated cresol-formaldehyde condensate; and a mixture thereof.
  6. The process according to claim 3 wherein the antifreeze agent is selected from the group consisting of ethylene glycol; propylene glycol; glycerine; urea; and a mixture thereof.
  7. The process according to claim 3 wherein the thickener is selected from the group consisting of clay; precipitated silica; polyvinyl elcohol; polyvinylpyrrolidone; polyacrylamide; and a mixture thereof.
  8. The process according to claim 3 wherein the preservative is selected from the group consisting of a 38% formaldehyde solution; methyl or propyl parahydroxybenzoate; 2-bromo-2-nitropropane-1,3-diol; sodium benzoate; glutaraldehyde; o-phenylphenol; benzisothiazolinone; methyl or ethyl 4-isothiazolin-3one; pentachlorophenol; 2,4-dichlorobenzyl alcohol; and a mixture thereof.
  9. The process according to claim 8 wherein the preservative is a 38% formaldehyde solution.
  10. The process according to claim 3 wherein the water-soluble pesticide is a water-soluble herbicide.
  11. The process according to claim 10 wherein said herbicide is selected from the group consisting of a quaternary salt of an amino phosphonic or phosphinic acid; a substituted phenoxy or benzoic acid salt; an imidazolinone; and a mixture thereof.
  12. The process according to claim 11 wherein said herbicide is selected from the group consisting of glyphosate; glufosinate; 2,4-D; MCPA; dicamba; imazaquin; imazethapyr; imazapic; imazamox; imazapyr; and a mixture thereof.
Anspruch[fr]
  1. Procédé pour la préparation d'une composition concentrée sous la forme d'une suspension aqueuse stable, qui comprend le fait de mélanger un courant de pendiméthaline en fusion ayant une température de 57 °C à 75 °C avec un courant aqueux contenant des coagents de formulation plus des germes cristallins de pendiméthaline orange, ledit courant aqueux ayant une température de -3 °C à 5 °C.
  2. Procédé selon la revendication 1, dans lequel lesdits germes cristallins sont présents à concurrence de 16 % à 24 %.
  3. Procédé selon la revendication 1, dans lequel lesdits coagents de formulation sont choisis parmi le groupe constitué par un agent tensioactif ; un agent antigel ; un agent antimousse ; un agent de mise en suspension ; un épaississant ; un conservant ; un pesticide soluble dans l'eau ; et un mélange desdits agents.
  4. Procédé selon la revendication 3, dans lequel ledit agent tensioactif est choisi parmi le groupe constitué par un produit de condensation d'oxyde d'éthylène/oxyde de propylène ; un éthoxylate d'alkylaryle ou d'arylaryle ; un lignosulfonate ; un produit de condensation de crésol-formaldéhyde ou un de ses suffonates ; un produit de condensation de naphtalèneformaldéhyde ou un de ses sulfonates ; un polycarboxylate ou un dérivé de ce dernier ; et un mélange desdits agents.
  5. Procédé selon la revendication 3, dans lequel l'agent tensioactif est choisi parmi le groupe constitué par un éthoxylate d'alkylaryle; un sel de triéthanolamine ou un sel de potassium de phosphate de polyarylaryléthoxylate ; un acide phosphorique de polyarylarylpolyoxyéthylène ; un produit de condensation de crésol-formaldéhyde de sodium ; un sel de sodium d'un produit de condensation de crésol-formaldéhyde sulfoné ; et un mélange desdits agents.
  6. Procédé selon la revendication 3, dans lequel l'agent antigel est choisi parmi le groupe constitué par l'éthylèneglycol ; le propylèneglycol ; le glycérol ; l'urée ; et un mélange desdits agents.
  7. Procédé selon la revendication 3, dans lequel l'épaississant est choisi parmi le groupe constitué par de l'argile ; de la silice précipitée ; un alcool polyvinylique ; de la polyvinylpyrrolidone ; du polyacrylamide ; et un mélange desdits épaississants.
  8. Procédé selon la revendication 3, dans lequel le conservant est choisi parmi le groupe constitué par une solution de formaldéhyde à 38 % ; des parahydroxybenzoates de méthyle ou de propyle; le 2-bromo-2-nitropropane-1,3-diol ; le benzoate de sodium ; le glutaraldéhyde ; le o-phényiphénol ; la benzisothiazolinone ; la 4-isothiazolin-3-one de méthyle ou d'éthyle ; le pentachlorophénol ; l'alcool 2,4-dichloro-benzylique ; et un mélange desdits conservants.
  9. Procédé selon la revendication 8, dans lequel le conservant est une solution de formaldéhyde à 38 %.
  10. Procédé selon la revendication 3, dans lequel le pesticide soluble dans l'eau est un herbicide soluble dans l'eau.
  11. Procédé selon la revendication 10, dans lequel ledit herbicide est choisi parmi le groupe constitué par un sel quaternaire d'un acide aminophosphonique ou aminophosphinique ; un sel d'acide benzoïque ou d'acide phénoxybenzoïque substitué ; une imidazolinone ; et un mélange desdits herbicides.
  12. Procédé selon revendication 11, dans lequel ledit herbicide est choisi parmi le groupe constitué par le glyphosate ; le glufosinate ; le 2,4-D ; le MCPA ; le dicamba ; l'imazaquine ; l'imazethapyr ; l'imazapic ; l'imazamox ; l'imazapyr ; et un mélange desdits herbicides.






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