CA2150920A1 - Microcapsule formulations of agricultural chemicals - Google Patents
Microcapsule formulations of agricultural chemicalsInfo
- Publication number
- CA2150920A1 CA2150920A1 CA 2150920 CA2150920A CA2150920A1 CA 2150920 A1 CA2150920 A1 CA 2150920A1 CA 2150920 CA2150920 CA 2150920 CA 2150920 A CA2150920 A CA 2150920A CA 2150920 A1 CA2150920 A1 CA 2150920A1
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- Prior art keywords
- water
- monomer
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- active
- weight
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/02—Making microcapsules or microballoons
- B01J13/06—Making microcapsules or microballoons by phase separation
- B01J13/14—Polymerisation; cross-linking
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
- A01N25/26—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests in coated particulate form
- A01N25/28—Microcapsules or nanocapsules
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Pest Control & Pesticides (AREA)
- Toxicology (AREA)
- Engineering & Computer Science (AREA)
- Dentistry (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Environmental Sciences (AREA)
- Plant Pathology (AREA)
- Dispersion Chemistry (AREA)
- Agronomy & Crop Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
A composition comprising highly concentrated microencapsules containing pesticides having a skin or shell wall of polyurea, polyamide, polysulfonamide, polyester, polycarbonate of polyurethane suspended in an aqueous liquid containing an elmulsifier which is a random co-or terpolymer of vinylpyrroiidone that will form a stable oil-in-water emulsion under the conditions described and a process for preparing said composition by mixing a liquid phase water immiscible pesticide to be encapsulated with a first shell wall component in the aqueous liquid to form an oil-in-water emulsion and then adding a second shell wall component to the emulsion causing the first shell wall component to react with the second wall component to form a skin of polycondensate shell wall about the pesticide to be encapsulated or alternatively when the first shell wall component is an isocyanate or mixture thereof allowing the first shell component in the emulsion to hydrolyze when to form amine groups which react with residual isocyanate to generate a shell wall of polyurea which suspensions may be used directly as an aqueous suspension or dried to form water dispersible formulations of microcapsules.
Description
BA-8~5-A ~ l ~ii O 9 2 0 .
TITLE
MICROCAPSULE FORMULATIONS OF AGRICULTURAL CHEMICALS
P~ACKGROUND OF THE INVENTION
The present invention comprises novel compositions and processes directed to S the p~c;pa dlion of microcapsule formulations cont~inin~ random co- or ter-polymers of vinyll,yllolidone as an em~ if ier to form an oil-in-water emulsion.
U.S. 4,208,833 teaches the use of lignosnlfonates as useful emulsifiers for highconcentration microenr~rs-ll~tPcl formulations. However, the microcapsules settle out and illevt;l~ibly pack in the bottom of spray tanks and in spray lines upon dilution with water. In contrast, the microcapsules of the present invention, which comprise a novel type of emnlcifier, readily resuspend upon dilution with water.
SUMMARY OF THE INVENTION
This invention comprises a composition comprising a highly conl ç~ ed rnicroencapsulçd active pesticic1P suspended in an aqueous liquid, said microPnç~rsuhPd pesticides comrri~in~ a liquid, melted solid or solution of an active pesticide in an unreactive water-immiccible solvent within an encapsulating wall of polymeric m~tPri~l wherein:
(a) said active pesticide being present at a concentration ranging from about 480 to about 700 grams per liter of composition;
(b) said en~rs~ tin~ wall of polymeric m~tçri~l is the reaction product of a first shell wall colll~onellt which is a flifunrti~nal or polyfilnrtion~l reactant soluble in the active Festicicle, and a second shell wall co~ ollenl which is water-soluble and which is a difunctional or polyfiln-~ti~ n~l reactant and wL~l~in the concentrations of said first and second shell wall colll~onents are from about 3.5% to about 21.0% and from about 1.5%
to about 9.0%, respectively, by weight relative to the weight of the active pesticide tQ be enc~rsul~tçcl; and (c) said aqueous liquid is water co".~ g (i) from about 0.5% to about 15% by weight of an em~ ifiPr relative to the weight of said active ingredient to be çn~arsnl~tPIl, said emnl~ifiPr being a water-soluble random co- or ter-polymer of vhlyl~yllolidone, and (ii) optionally, from about 0.01% to about 30% of a formnl~tiQn adjuvant based on the total weight of the colllposilion.
This invention also comprises a process for pr~pa~ g a highly concentrated composition of particles of a microPnr~rslll~ted pesticide in water whe.chl the pestici~l~P.
is encapsulated in a plastic shell with subst~nti~lly no agglomeration of the particles, said process col"r~ lg ~cj~
21S~9~ D
(a) mixing a water-immiscible monomer A and an active pesticidal ingredient, in the form of a liquid, melted solid or solution of said active ingredient in an unreactive water-immiccible solvent, said monomer selected from the group consisting of diacid and polyacid chlorides, dichlorof~rm~tPs, polychloroformates, disulfonyl and polysulfonyl chlorides, diisocyanates, polyisocyanate and mixtures thereof, to form a solution of monomer in the active ingredient;
(b) dispersing in water cont~inin~ an emnlcifiPr~ the solution of the monomer and active ingredient, said emlllcifier being a water-soluble random co- or ter-polymer of vinylpyrrolidone, to form an oil in water emulsion with droplets in the size range of 1 to 100 microns;
(c) adding to the emulsion of (b) a water-soluble monomer B which will react with monomer A by intr.rf~ri~l polycon-lçn~tion to form a shell around the pestici~
ingredient, said water-soluble monomer B selected from the group cnncicting of ~ minP.s or polyamines, diols or polyols; or ~ iv~ly when monomer A is a diisocyanate, a polyisocyanate or mixtures thereof, optionally including a catalyst in the solution from (a) and heating the emulsion of (b) to hydrolyze monomer A to amine groups wl~ eby the amine groups generated by hydrolysis react with residual isocyanate monomers to generate a shell wall of polyurea;
(d) optionally, adding formlll~tion adjuvant(s); and (e) optionally, drying followed by granulation of the solid residue to form a flowable solid composition.
Dl~TA~T F.n DESCRIPTION OF T~TF T~VENTION
This invention conl~lises compositions cont~inin~ and processes for producing small or minute c~psllles con~ g a water-immi.ccible active pestir,i~r. By a process called interfacial polycon-l~n.c~tion, a monomeric first shell wall co.l.~?onellt (monomer A) is dissolved in a water-imrniscible active pesticide, or solution thereof. The resultin~
solution is l1i.cpçrced in water co~-t~;..i~-g an emulsifying polymer sçl.octed from co-polymers or ter-polymers of polyvinyl~yllolidone (PVP) to form an oil-in-water (O/W) emnlcit~n. Thel~,drt~,r, a second mon~ m~ric shell wall component (monomer B, usually 30 dissolved in additional aqueous phase liquid) is added to the oil-in-water emulsion whereby the second shell wall colllpol enl reacts with the first shell wall colll~ollent to form a polycoll-lenc~te shell wall about the water-immi.ccihle pestiCi~l~ at the oil/water intrrf~r.e High concentration :~u~pæ~-.cions cont~ining a larger volume of pçstici(le co~ onenl~ inside the microcapsules than the volume of water suspending the 35 microcapsules, are produced by interfacial polycon~lrnc~tion.
In some inct~nres, the second shell wall forrning co---~ollenl is u~m~çs.s~y. By a process called in situ microçnc~ps~ tion, isocyanate monomers are dissolved in the water-imrniscible active pçsticid~l ingredient, and the solution is dispersed in water co~ g A~EN~ED ~1 ,. ~ 21509~0 an emulsifying polymer selected from co-polymers or ter-polymers of vinylpyrrolidone.
Amine groups generated by hydrolysis reaet with residual isoeyanate monomers, generating a shell wall of polyurea. A eatalyst that will speed the hydrolysis of the isocynate may be included in the monomer in the active ingredient solution. These are S well known in the art. One such catalyst is dibutyltin dilaurate. Heat is applied to also speed the hydrolysis. Generally, when a catalyst is used a telllp~,ldLule of 20 to 60C is sufficient to carry out the hydrolysis in one hour. However, if the catalyst is not used a temperature of 58-75C will require several hours, e.g., 12 hours for the hydrolysis.
Microencapsulation is especi~lly useful for making high concentration solid 10 formulations of liquid pesticides. Without microencapsulation, unencapsulated liquids must first be absorbed onto inert carriers to create dry powders which can be gran~ tçd to dry solid water-dispersible form~ tions. With large amounts of inert earrier required to absorb liquids, solid dry formlll~tions of llnP.nl~ps~ t~P~ liquids are nPcçcs~rily dilute.
Without micloenca~ultation""~xil"..." qu~ntitiP~ of unPn~psulated liquid in dry solid 15 form~ tions is about 40%. By contrast, microcapsules contain at least 90% liquid and ean be form~ tPrl to dry solid forml-l~tion~ whieh may eontain more than 70% liquid pestieide.
Once enc~ps--l~tP~i, the liquid or other form of the aetive pestieide (e.g., meltable solids) is preserved until it is released by some means or hl~llul~ nLality that breaks, 20 erushes, melts, dissolves, or otherwise removes the eapsule skin or until release by diffusion is effeeted under suitable eonditions. Mieroçn~ ~ps~ tion reduees aeute toxieity of pçstici-l~e, improves biological efficacy, may reduce l~chin~ into groundwater, and ean isolate in~ompatihle pestieides from eaeh other within the same f~rmlll~tion.
Despite these advantages, mieroenrars~ tion is not e~Lèll~ively utilized beeause25 early proeesses produeed dilute eomposiLions. Colloid stabilizers utilized to (li~pçrse the oil phase are erre ;Live only if the conLilluous aqueous phase is a larger volume than the pP~ed oil phase. When colloid st~bili7Pr~ are utilized for high con(~çntr~tion microen~ tion, microcapsule aggregates are produced.
We have diseovered that eertain eml-l~ifier~, random eo-polymers and ter-30 polymers of vinyl~yllolidone, ean he advantageously used in the process ofmieroenrarsul~tion using an interf~ei~l polyeontl~Pn~tion reaetion bGlwGen reaetivemonomers within the oil and water phases, or in the proeess of in situ mieroeneapsulation with isoeyanate monomers eontained in the oil phase. After dilution into water the settled mierocapsules prepared by these proeesses are readily resuspended 35 and do not aggloll~ dle. The present invention provides new elle~rs~ tion proeesses whieh are erÇe-;tiv~ to ~ te high conccll~dlions of water-immiseible agrieultural produets to provide high eoneentration sl~spçn~ions of mierocapsules, or dry dispersible formulations ~ a~cd by drying and gr~n~ ti~n of the rçs--lting solid mic,-,cdl,~lllçs 21~0920 A critical feature of the present invention is the use of the specific type of emllleifier~s to form sufficiently stable oil-in-water emulsions so that a concentrated amount of active pesticide is present in the water-immiscible phase and is therefore encapsulated. Generally, there is greater than 480 grams of active pesticide or active 5 pesticidal solution per liter of total aqueous composition. Dry solid formulations contain greater than 70% liquid water-immiscible m~teri~l in dry water-~ pereihle form.
The microcapsules of the present invention may contain dyes, inks, chemical agents, ph~rm~reuticals, flavoring materials, pesticides, biological agents, plant growth regulators, and the like. Any liquid, oil, meltable solid, or solvent soluble m~tPri~l into 10 which shellwall monomers can be dissolved and which are nonreactive with tne monomers may be encapsulated.
In the practice of the preferred embodiment of the present invention, the m~teri~l to be enr~ps~ tPd is a water-immiscihle active pesticide. As in-lic~tPd above, the active pesticide is any liquid, oil, or meltable solid, to which the first shellwall monomeric 15 co~ ollent is unreactive. In addition, a water-immiscihle active pesticide can colll~lise a solution of an active pesticitle in an unreactive water-immiscible solvent.
The active pesticide is selected from the group consisting of herbicides, in.secticides, acaricides, fungicides, nematocides, bactericides, biological pest control agents, herbicide safeners and plant growth regulants. Examples of suitable a~ri~lllhlral chPmi~le include:
20 herbicides such as acetochlor, aciflllorfen, alachlor, asulam, atrazine, beneulfilron methyl, bentazon, bromoxynil, butachlor, hydro~yl~nzollillile, chlola llben, chlolilllulùil ethyl, chloroxuron, chlorsulfuron, chlorotuluron, clomazone, cy~n~7inP, dazomet, l~PsmP~lirhan, ~ mb~ dichlorbenil, dichlorprop, diphPn~mitl~ diplù~ yll, diuron, thi~lllr~ un~ fenac, fluolllt;lulvn, fluridone, folllPs;~r~i-, gly~hos~Lt:, im~7~mPth~benz,5 imazaquin, hllazelll~yl, ioxynil, iSOpÇulurOII, isouron, isoxaben, karbutilate, tr~ t~
tP~, triflllr~lin, linuron, lenacil, MCPA, MCPB, mPfluitli-le., metha~e~ llron~
mPth~7olP., mPtol~hlor, metribuzin, mPtelllfilron methyl, monuron, n~pt~l~m, neburon, nitr~lin, nolnuld~on, oryzalin, perflllidonp" phel.l,,P~lirh~ plulll~llyll, plu~ e~
pl~azil~, ~yldzon, rimsulfuron, siduron, eim~7ine, sulrùlll~lul~on methyl, tebu~ulon, 30 terbacil, telbu~lylazine, telbullyll, triclopyr, 2,4-D, 2,4-DB, tri~eulfilron~ tribenulo methyl, primieulfilron~ ~y-,17o~ulfilron ethyl, N-[[(4,6~1imP,thoxy-2-wrimidinyl)amino]carbonyl]-3~ethylsulfonyl~2-pyridine-sulfon~mide, nicosulfiuron, 2'-t-butyl-2-chloro-N-methol~ylll~lllyl-6'-methyl~ret~nilidP, oc-chloro-N-(2-methoxy-6-1llt;lllylph~,llyl)-N-(1-methyletho~ylllcilllyl)~et~mi-l~P-, a-chloro-35 N-(etho~ylll~lllyl)-N-[2-methyl-6-(trifluorolllt;l~lyl)phenyl]~et~mi-le, a-chloro-N-methyl-N-[2-methyl-6-(3-methylbutoxy)phenyl]~et~mid~P, a-chloro-N-methyl-N-((2-methyl-6-~J, ~ 2150920 propoxyphenyl)~et~mide, N-(2-butoxy-6-methylphenyl)-oc-chloro-N-methyl-~cet~midç, isobutyl (2,4-dichlorophenoxy)~cet~te, 1-(1 -cyclohexen- 1 -yl)-3-(2-fluorophenyl)- 1-methyl urea, and ethametsulfuron methyl; fungicides such as carben(l~7im, thil-r~m, dodine, chloroneb, cymox~nil, captan, folpet, thiophanate-methyl, thiabendazole,S chlorothalonil, dichloran, captafol, iprodione, vinclozolin, k~cug~mycin, thi~-limPnol, flutriafol, flllci1~ol, hexaconazole, and fenarimol; bactericides such as oxytetracycline dihydrate; acaricides such as hexathizox, oxythioquinox, dienochlor, and cyhP~tin;
incectici~lPs such as c~l,or~lldn, carbyl, thiodicarb, delt~mpthrin~ methyl and ethyl parathion, pyrethrin, permethrin, fenvalerate, and tetrachlorvinphos; and herbicide 10 safeners such as 5-thiazolecarboxylic acid.
The m~tPri~l to be encapsulated need not consist of only one active pesticide, but may be a combination of two or more active pesticides. For example, such a combination may be a herbicide with another active herbicide or a herbicide and an insecticide. Also cun~ lplated is a water-immicçihle m~teri~l to be encapsulated which 15 comprises an active ingredient, such as a herbicide, and a non-pesticidal ingredient such as an adjuvant or inert m~tçri~l to achieve some special plo~~
The water-immiccihle active pesti~ P when in liquid form may act as the solvent for the first shellwall component, or espeçi~lly when the active pestici-le is a solid, the use of a water-immiscible organic solvent such as methylene chloride, ~lk~nPs, benzene, 20 toluene, xylenes, etc., may be used. The use of a liquid active pesticide without additional organic solvent allows for a concentrated amount of the active pesticide in the final en~rs~ tPd product. The water-immi~ihle active pesticide and first shellwall colll~ollent are added cimlllt~n~ously to the aqueous phase in a pre-mixed state. That is, the water-immiscible m~teri~l and first shellwall component are pre-mixed to obtain a 25 homogeneous organic liquid phase before addition to, and emulcifi~tior~ in, the aqueous phase to form the oil-in-water emulsion.
The concenl-dlion of water-immi~cihle active pçsti~ide initially present in the water-immiscible phase should be sufficient to provide at least about 480 grams of water-immiccihle active pesticide per liter of total aqueous composition. In practice, as 30 is recognized by those skilled in the art, the use of e~ llely high concentrations of water-immiccihle active pPstici~le results in undPcir~hly thick ~u~nsions of microc~pslllPs. In general, the concentration of water-immiscible active pesticide ranges from about 480 grams to about 700 grams per liter of total aqueous composition. The preferred range is from about 480 grams to about 600 grams per liter of total aqueous 35 composition.
The shellwall of polycon-lPnc~te may be a polyurea, polyarnide, polysulfon~mi-le, polyester, poly-,~bollah, polyurethane or mixtures thereof. The following are specific inct~n~es of polycon~l~Pnc~tion reactions to which the present en~ tion process is applicable. Di~mines or polyamines in the water phase react with diacid or polyacid chlorides in the organic phase liquid to yield capsule walls co,~ ; of polyamides.
Diamines or polyamines ill the aqueous liquid cnn-len.~e with dichlororo. ., .~t~s or polychlorl,rJ l..~t~Ps in the organic liquid to form a polyul~,ll~ capsule skin. Di~mines 5 or polyamines in the a~lueous liquid react with disulfonyl or polysulfonyl chlorides in the organic liquid to produce apolysulfon~mide capsule skin. Di~mines orpolyamines in the aqueous phase liquid and a dii~o-;yallale or polyisocyanate in the organic phase liquid react to form a polyul~ a skin. With diols or polyols in the aqueous liquid and diacid or polyacid ~ hlori~lP~ in the organic phase liquid, polyester shellwaUs are produced. When 10 bischloluru....~t~s orpolychlc,rùf ....-:-t~s are used in the organic liquid, the capsule skins are polyc~l,ollalcs.
It will further be a~ ,cialcd that not only are there other complemPnt~ry intPrmetli~tes which react to form polyco~ ,5 in a manner useful in the intPrfa~
polyco~ si~l ;on ~locess of ~ tion, but various ll~ Ul~ s of intermediates, i.e., 15 l~ Ul~ s of shellwall cc""~one,lls, may be employed in either or both of the aqueous and organic phases. For P~mrle, mi~ctures of diols and ~1;;..ll;l~F~ in the aqueous liquid and acid ~hlori-1~(s) in the organic liquid are useful to achieve pol~,,t~olyamide con-~ l ;o.~ copolymers. Also, ~ min~s or polyamines in the a4ucuus liquid and llliAlUl~S of diacid or polyacid chlorides and di~ocy~lat~ s or polyiso~;y~les in the 20 organic liquid produce a polyamide/polyurea skin.
F.~mrleS of suitable l;r....~ acid-derived shellwall components suitable as monomeric colllpol,~ s for the organic phase are s~bacoyl chloridP" ethylene bischlolurc.. ~te, rhosgP.nP~, t~ )hlh~loyl ~hlori-lP., adipoyl .hlori-le, azelaoyl r.hlori~lP.
(azelaic acid chl~ rirle), dodec;~ ;oic acid chloride, dimer acid çhlori-1P~, and 1,3-25 be .~ F,~ fonylrlirhloritle Polyfilnt~tion~l co",~oul~dsofthis~h; .i-~t~ . areP~rPmrlifi by trimesoyl chl--ritle 1,2,4,5-b~ ~ nc tetracid chloritl~P, 1,3,5~ f trisulfonyl chloride, tnmer acid r~hlori(le, citric acid rhloritle, and 1,3,5-l~ ne tri.sçhlolurol",ate.
Monomers similarly useful in the organic phase include diisocy~,al~s and polyiso~;yallaL~s" for e~cample, toluene diiso~;y~,ate, h~methylene diiso.;yal~dle, 30 methylene dipll~llyliso~-y~l~e and poly,.,~,ylene poly~l,ellylisocyanate.
F.~mrles of suitable diols for use as monomers in an aqueous phase are bisphenol A [2,2 bis-(p, p'-dihy~uAy diphenyl)pluL)~le], hydro4uil,one, l~so~ ol, catechol, and various glycols such as ethylene glycol, ~...~ iol~ hP~n~-~liol, do-lec~.-ftliol, l,~bllt~ne~ l and the like. Polyfimt~tion~l alcohols of this character, e.g., 35 triols and polyols, are PYPmrlifiPcl by pyrogallol (l,2,3-1;~ -->f ~ ;ol), phlorogl~lçint-l dihydrate, pentae.y~ ilol, trimethylol~;lv~anc, l,4,9,10-tetrahyd,u~ya.~ cenc, 3,4-dihycllu~y; ..1l.t~ 01, dil~sorcillol and tetrahy~Lu,~y~ ;..on~
~ 21~09~D
Suitable ~ minPs and polyamines for use as monomers in an aqueous phase, usually selected as water-soluble per se or in water-soluble salt form, are ethylene minP, phenylene ~ minP, toluene ~ minP, hexamethylene ~ minP, diethylene tri~minP
and pipe.azille. Amines which are effective as polyfunctional re~ct~nt~, are, e.g., 1,3,5-S benzene tri:~minP trihydrochloride, 2,4,6-tri~mino toluene trihydrochloride, polyethylene imine, 1,3,6-tri~min~narl~ lPn~, 3,4,5-tri~mino-1,2,4-triazole, melamine, and 1,4,5,8-tetramino anthraquinone. Amines which have greater than 2 but less than 3 amine functionalities and which may provide a degree of cr s~linking in the shellwall are the polyalkylene polyamines of the type R R
H2N(CH2)mCH--HN(CH2)nCII NH2 wherein R equals hydrogen or CH3, m is 1-5 and n is 1-5, e.g., tetraethylene ~,~pentaethylene hexamine, and the like.
In intPrf~ l polycon-l~n~tion, the amount of first shell wall co~ onenl and second shell wall component used in the process determinPs the percent shell wall content produced. Generally, there is present in the reaction from about 3.5% to about 21.0% first shell wall component, and from about 1.5% to about 9.0% second shell wall component, relative to the weight of the water-immiscible m~t~ri~l A stoichiometric amount or excess of second shell wall component may be used. The shell wall content of the capsules which results varies from about 5% to about 30%, preferably 8 to 20% and more particularly, 10% by weight, based on the weight of the active ingredient to be 20 encapsulated.
Represenl~ti~. of isocyanate monomers suitable for in situ micr~en-~ps~ tion are the following: 1-chloro-2,4-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 2,4-tolylene diisocyanate, tolylene diisocyanate (60% 2,4-isomer, 40% 2,6-isomer), 2,6-tolylene 25 diisocyanate, 3,3'-dhll~ yl-4,4'-biphenylene diisocyanate, 4,4'-methylenbis(2-l,wlllylpll~llyl isocyanate), 3,3'-dimethoxy-4,4'-bi~hellylene diisocyanate, 2,2',5,5'-le~ hyl-4,4'-biphel,ylene dusocyanate, 80% 2,4- and 20% 2,6-isomer of tolylene diisocyanate, poly",~lllylene poly~henylisocyanate (PAPI(~), and llli~ures thereof.
The amount of organic polyisocyanate used in the in situ micr~ n~r,~ tion process d~ s the shellwall content of the c~ps--les formed therein. The preferred range is from about 5.0% to about 30.0% relative to the weight of active pesticidal ingredient to be e~ ul~t~d Most ~r~fe,l~d is about 10% relative to the weight ofactive ingredient to be en-~ps~ t~l 21~0920 What is meant by an emulcifier is a copolymer or terpolymer of vhlyl~yllolidone wherein the vinyl~yll~ lidone is present in sufficient amount to provide the copolymer or terpolymer with the properties described below. The emnlcifierc of the invention are copolymers and terpolymers composed of any non-aromatic water soluble monomers polymerized with vinylpyrrolidone to produce water soluble copolymers and terpolymers which are capable of forming a stable oil-in-water emulsion under the reaction conditions described herein. Any polymer combination which includes s--fficient vinylpyrrolidone to render the whole polymer combination to be water soluble is expected to be useful as an emulcifier of the present invention. This includes copolymers, terpolymers of vinylpyrrolidone wherein the copolymer and terpolymer includes any number of different polymers in combination with vinylpyrrolidone that results in the copolymers andterpolymers being water soluble and capable of producing a stable oil-in-water emulsion under the present conditions. ~le~ell~d copolymers include VP copolym~qri7~d with 1) vinyl acetate, 2) dhllt;Lllylalllinolll~llylln~ rylate, and 3) qu~~ d dimethylaminoe~lyl",r~ crylate. The weight percent VP in the copolymers is 20 95%, preferably 50-85%. Preferred terpolymers include VP copoly~ ed with capr ll~ct~mand dimethylaminomethacrylate. The weight percent VP in the terpolymers is 10-80%, preferably 15-50%. Specific c~ l~r~ially available VP copolymers are Agrimer~
DA-10, Agrimer~ DA-1, A~lhlle.'~) DAQ-300, Agrimer0 DAQ-2000 and Agrimer~
VA-6. Agrimer~9 DAVC is lepleselllaliv~ of terpolymers which are also effective for use in practice of the invention. These polymers are m~nllr;~ ed by Tntern~tional Specialty Products, 1361 Alps Road, Wayne, New Jersey, 07470. Preparation of these polymers is described in U.S. 4,520,179; U.S. 4,520,180; U.S. 4,554,311; U.S. 4,554,312; U.S.
3,691,125; and U.S. 4,521,404.
The range of emnlcifier concentr~tion found most acceptable in the system will vary from about 0.5% to about 15% and preferably 2% to 6%, based upon weight of the active ingredient to be er-c ~ps~ ted The micloca~ules of the present invention require no additional tr~tmP-nt such as separation from the aqueous liquid, and may be directly lltili~Pd The aqueous~us~llsions are suitable for many applications depending on the water-immi~ihle m~teri~l which is en~rsnl~te(l For çx~mrle, an aqueous sllcpencion of Illis~ lçscont~ining a herbicide may be combined with liquid fertilizers, insecticides, or the like to form aqueous solutions which may be conveniently applied for agri~ultllr~l uses.Often it is most convenient to bottle or can the aqueous ~ l~n~ion cont~ining the enr~psul~ted water-immiscible m~tt?ri~l in which case it may be desirable to add formlll~ti~n ingredients to the aqueous solution of microcapsules. Formul~tion adjuvants such as density balancing agents, thie~n~rc, biocides, sllrf~rt~ntc, .li~ "lc, salts, anti-freeze agents, and the like can be added to i-..~ ve suspension stability and the ease of AMEND~D SHFET
21~()920 Wo 94/13139 ^ PCT/US93/11523 applic~tit n If a formnl~tioll adjuvant is added to the aqueous ~u~ensivl of microc~ules such ingredients are ~lGr~ably added at a conc~ ;o" of from about 0.01% to about 30% by weight of the su~ension.
If it is desired to adjust the pH of the ri.~i~l.rd miclocAp~ formnl~tion as, for S ~mple, when the aqueous solution of fini~hf d mic;rvca~ule is cnmbin~-l with other pestic~ s, con~ n~l reagents for ~.lj.-~l-..~ -l of acidity or ~lk~linity, may be used.
For ç~mple, suitable snb~ ce,s are hydrochloric acid, sodium Ly~llvAide~ sodium c~l,on~le, and sodium bicaLl,vll~le.
Thus the pçsticitl~l col,l~vsilion may be in liquid form co...l.. ;si.-g the su~nsio 10 which results after the microf -~p~ tion re~ction ~ I;v~;ly~ the pesticidal composition may be in solid form by drying the ~u~ension which results after microf .~r~ ti-)n and then gr~mll~tin~ by using well-known techniques to afford a dry microencapsulated granule cvlll~osi~ion.
In pr~cticing the ~rvcess of the present invention, the ~ e.a~ult; should be 15 m~;, ll~;llf ~1 above the melting point of the pesticide if used neat, or the unreactive solvent if a pesticide solutiolt is used. The t~,l*e.~lul~; should also be kept below the point at which the water-immi~r-i~le monomer hydrolyzes or olllt,.wise clçco,..l)oses. For example, where it is desired to e~ "l~t a solid herbicide wi~ ul solvent, it will be llf cçss~y to heat the herbicide to its molten state. Alachlor herbicide, for e~ample, mdts at 39.541.5C and the l~,."~tur~ of the process should ~ccor~l;,.gly be m~ Fd above about 41.5C.
The~g;t~l;o,-employedto~st~hli~hthe.l;~ ;ol-ofwater-;....~.is~;l,ledro~ sin the a~ueous phase may be supplied by any means capable of providing suitably high shear. That is, any variable shear mi~ing a~al~lus, e.g., a hl~nd~r, a homogenizer, etc.
25 can be employed to provide the desired ~git~tinn The p~rtir~ r size of the microc~pslllçs will range from about 1 micron up to about 100 microns in ~ me.tr.r. A ~rt~l~t_d range is about 1 to about 50 microns. From about 1 to about 10 microns is an optimum diameter range.
The present invention is further explained by the following F~mrl~s which are 30 ;11~ I;VG and not limiting in nature. Unless uLh~,w~sc in~ te~lJ the int~rf~ri~l polycon~l~n~tio~ F.~mplçs which follow were ~- ru....erl as follows: thé water-immi~rihle m~teri~l, co,~l~;";"~ the first shellwall colll~ollelll(s) dissolved therein, was emnlcifiçd into water co,~ the rm~ if içr; the emulsion was formed with the aid of high shear. The second shell wall coll~un~ (s), usuaUy dissul~ d in an ~ ition~l35 amount of aqueous phase liquid, was ~ c~l~,ï added to the ~m~ ion and after a short period of time, the shear rate was re~lllce~l She~r was contimled for varying periods of time and t~C~ L~ salt or a ~u~.ldillg aid was added if ..ecess~y to stabilize the suspension. The form~ ti~l~ was then bottled.
-WO 94/L3139 ~,~9~,~ PCT/US93/11523 --In the process of in situ microencapsnl~ti- n, the isocyanate monomers were dissolved in the water-immist ihle phase along with a catalyst. An çmnl~ion was made and slower shear was co~ -c~l and the te~ tUl~:; raised to speed the shell wall forming reaction. The shellwall component is formed by the reaction of the amine 5 hydrolysis product and residual isocyanate.
FX~MPLE 1 This F~mrle shows the use of Agrimer~9 DAQ-300 (vinyl-pyrrolidone/~ t~ 1 dil~ ylan~-o~ll-yl ...~ ylate co-polymer 300,000 molecular weight) to emulsify- an acet~nili-le herbicide at ele~ d t~ ulc for 10 microencapslll~tion 200 Grams of ~e~hnic~ rhlor (93.8%) Co.~A;";..g 13.9 grams of PAPI(~) 2027 (a polyll~ ylene poly~ .lyliso~iydn~ s from the PAPI series by Dow ~h~mit ~l CO1l1~J~1Y) was emulsified into 152.38 grams of water co.~ g 10 grams of Agrimer~
DAQ-300. All m~t~ri~l~ were m~;..l~;...o..~ at 50C. The t-mnl.~ion was formed with a 15 Waring blender ~.~ lg at high shear. To the emnl~ion, after 1 min., was added13.9 grams of 43.37% ht~methylL.~tli~...;..e and shear was reduced to a stirring shear.
After S min. of stirrin~ 32.8 grams of sodium chlori~le and 22 grams of 1% Kelzant~, a ~nth~n gum thi~ ner, were added. Stirring co.~l ;....e~l for 15 min. and the ft)rmnl~tit)n was bottled. Discreet spht-rit ~1 microc~rsnles 1 to 40 llliClUnS in tli~mett.r were 20 observed microscù~ically. The form~ tion was stable through acc~lt -~e-l aging at 54C
and after several weekly IC~ U1C cycles b~ &l -4 and +54C.
l~XAl~LE 2 ~ is E~ample shows micro- -~A~ ti~n of ~ hlor at ele~ted tc~ ulti using Agl~nOE~9 DA-10 (villyl~yllùlidone/dimelllyl;~linsethyl m~ ylate co-polymer) 25 as lom~ ifi~r 200 Grams of technic~ hlor (93.8%) co. ~1; ;. .;. .g 13.9 grams of PAPI(~) 2027 was emulsi~led into 152.38 grams of water co..li~;..;..g 6 grams of Agrimer~9 DA-10. All m~t~ri~l~ were m~int~ ~ at 50C. The ~mnl~if~n was formed with a Waring blender o~>el~i,lg at high shear. To the f mnl~ion, after 1 min., was added 13.9 grams of 43.37%
30 hexamethyl~ne(li~min~o and shear was reduced to a stirring shear. After 5 min. of stirring, 32.8 grams of sodium chloride and 22 grams of 1% Kelzan~, a ~nth~n gum thickener, were added. Stirring continned for 15 min. and the ff~rmnl~ti()n was bottled. Discreet h. - ;f ~l micl~,c~ules 1 to 50 microns in fli~mf,t~r were obs~,d micr~sco~ically. The formulation was stable through ~cc~ l aging at 54C and after several weekly L~ Gl~lUlG cycles btL~ ,.l -4 and +54C.
2I~0920 WO 94/L3139 PCT/US93111~23 F~MPLE 3 This F.~mrle shows miclo ~r~ tion of ~lArhlor at d.,~alt;d ~ alule using Agrimer~) DAQ-2000 (vu~yl~ylr~lidone/~ t -..~ e~llylamulG~lhyl ...clhA~ .ylate co-polymer 2,000,000 molçcnl~r weight) as rm~ if i~-r 200 Grams of terhnic~ rhlor (93.8%) co.~ 13.9 grams of PAPI(~ 2027 was em~ if i~l into 150.38 grams of water co~lAi~ 4 grams of Agrimer~) DAQ-2000.
All m~t~ri~l~ were m~;..l~;..Pd at 50C. The emlll~ion was formed with a Waring blender o~e~l..lg at high shear. To the Pmnl~ion, after 1 min., was added 13.9 grams of 43.37%
hexamethylc ~c~ in~ and shear was rç~lced to a sti~Ting shear. After S min. of stirring, 32.8 grams of sodium chloride and 22 grams of 1% Kelzan~, a ~nth~n gum thirl-rn~r, were added. StilIing co..l ;..-,ecl for 15 min. and the formnl~tion was bottled. Discreet ~h~ A1 micl~,cA~ les 1 to 25 microns in ~ metPr were obs~ ~ d microscopically. The formulation was stable through ~cc~ ,d aging at S4C and after several weeldy t~ll~ `t cycles b~.L'.. ~ n 4 and +54C.
~AMPLE 4 This F.~c~mple shows mi.;l~ c~ tion of ~l~rhlor at cle~,al~d t~.ll~lalult using AgIimer~ DAVC (villyl~y~ np~lvinylc~ yla-m meth~l~rylate ter-polymer) as çmnl~ifiPr.
200 Grams of t~h~ Al ~l~rhlor (93.8%) co.~ g 13.9 grams of PAPI~ 2027 was ~mnl.~ifi~l into 160.38 grams of water c~ g 8 g of Agrimer~) DAVC. All m~teri~l~ were mAi.~ at 50C. The Pmlll~ion was formed with a Waring blender o~ g at high shear. To the f-mnl.~ion, after 1 min., was added 13.9 grams of 43.37%
he~camethyl~ ...in~ and shear was r~luced to a stirring shear. After S min. of stirrin 22 grams of 1% Kelzan~, a ~..lh~. gum thi~ oner~ was added. Stirring continnecl for 25 15 min. and the formnl~tinn was bottled. Discreet s~ -- ;cAl microc~rs lles 1 to 15 microns in ~ met~r were ol)s~d miclosco~ically. The form~ tion was stable through accele al~d aging at 54C and af~er several weekly t---~ cycles l~l.. C~
-4 and +54C.
COMPARATIV~ EXAh~L~ A
30This ~.,..... p~.~live F~mrle shows miclu~ a~ tion of ~ hlor at elevated ~ll,U~,rall.Jlt; using Rea~ D 88B (a 1;~nO;j~1rU~ e P~ ;r;~ r).
200 Grams of te~hnir~ hlor (93.8%) co.~ g 13.9 grams of PAPI~ 2027 was emulsified into 150.38 grams of water co~ g 4 grams of Rea~9 88B. All m~teri~l~ were m~ at 50C. The .omnlsion was formed with a Waring blender u~e ~l~ng at high shear. To the em~ ion, after 1 min., was added 13.9 grams of 43.37%
hex~l,ethyk . .~ .. .in~ and shear was reduced to a stirring shear. After S min. of stirring, 32.8 grams of sodium çhlnri-le and 22 grams of 1% Kdzan~, a ~ gum th~ n~r~
were added. Stirring co"l;..-Je~l for 15 min. and the formnl~tion was bot~ed. Discreet WO 94/13139 ~ 1 5 0 91 2 ~ PCTIUS93/11523 --sph.ori~l microc~rs~ s 1 to 20 microns in ~ met~.r were ol)se.~,ed microsc~ically. ~he formulation was stable through acc~ fl aging at 54C and after several weekly GlllpGla~UlC cycles b.,~ 4 and +54C.
Rei,u~ dability of settled solids from diluted fnrmnl~tion~ prepared in F~mrles 5 14 and Coll~aLaLivG F~mrle A was tested as follows: Into 95 grams of tap water in Nessler(8) tubes was added S grams of the formnl~tion The Ne.,i,l~ tubes were inverted several times and shaken to thoroughly sùspènd the formnl~tion~ and then left nn~ ed for 3 days at room t~ll~ LulG. The~Nessler~ tubes were then slowly inverted and the number of inversions required to l~i,u~Gl~d the settled microc~psul~s 10 was recorded. Data are shown in Table 1.
T~RT.F, I
Number of Inversions P~çq ire(l to Rei,u~e,-d Settled Microcapsules after 3 Days FORMULATION F~ULSIFIE~R ~V~RSIONS
~xample 1Agrimer~9 DAQ-300 10 r~mrle 2 Agrimer~) DA-10 12 r~ 3 Agr~ner~9 DAQ-2000 4 ~ample 4 Agrimer~ DA~C 29 Comp. F~mrle ARea~) 88B >100~
~Requ~red vigorous shaking to , ' the settled l.~,lU~ v s We consider 30 ill~. ,~s to be the ,lally acc~l ' cut off.
COMPARA~ ~L~ B
This co )auaLive t~ mple shows aLh,..l~t~d micrG~ tion of alachlor at devated le.,l~l~tul~; using A~i..le~lD ST (v..lyl~yllolidone/styrene copolymer).200 Grams of terhni~ hlor (93.8%) co"~ 13.9 g of PAPI 2027 was ~mnl~ifi~-l into 152.38 g of water co.. ~ g 10 g of A~ 10 ST. All m~tçri~l~ were m~ rrl at 50C. The ~mnt~ion was fonned with a Waring blender o~ g h~ .ylen~ mint~ Upon~d~litionof~ mine~instantso~ fi~tionoc~ ,d. No useful microcd~ les were obtained.
E~LMP~.F 5 This E~cample shows microencapsulation of a liquid cineole herbicide, cinmethylin, with AgrQner~) DA-10.
80.00 Grams of cinmethylin co.~ g 5.56 grams PAPI~ 2027 was ~mnl~ifiçcl into 62.61 grams water c~ E 1.6 grams Agrimer~) DA-10. An ~mnl~ioll was formed at high shear with d Waring blender. To the ~mnl~ion, after 1 min. of shear was added 5.56 grams of 43.37~o hf~methyl~n~ mint~.. After an ~ 1itif~n~1 15 min. of slow shear stirring the form~ tion was bottled. Discreet, individual mi._.uci.l,s..l~s ~ ~15092~
WO 94/13139 ^ PCT/US93/11523 1-50 microns in ~ meter were obs~v~.d micr~sco~ically. The formnl~tinn r~m~ined fluid and readily l~,.,.~s~ .ded with time.
CC)MPAR ATrVE EX:AMPLE C
This ~Y~mrle shows the au~ t~ d micl~ tinn of a liquid cineole 5 herbicide, c;~ hylil~ with Agrimer~l9 ST (vi~lyl~yll~lidone/~Lyl~e copolymer).Fs~mrle 5 was l~al~l e~actly as dçs~ril~ed e~cept that 1.6 g of Aglil~ ) ST
was used in place of 1.6 g of Aglilll~0 DA-10. The ~mnl.~ion formed well, however, when ~ minP was added to the ~mnl~ion it became a pastey m~t~ri~l Micr~sco~icaUy it a~L)ca.~d that microc~rslll~s may have formed, however, they were highly ag~,l~hL~d 10 and the entire colllposi~ion was not a useful ~u~,ns;on of diSC~ ,l microc5 E3~AMPLE 6 This F~mrle shows micio~ tinn of a liquid cineole herbicide, t~inmethylin, with A~ .~ VA-6 (vil.ly~ylluli~lo~ /vinyl acetate r~n~lom copolymer having 60% pyrrolidone and 40% acetate by weight).
80.00 Grams of cinmethylin co~.~ g 5.56 grams PAPI~9 2027 was ~mnl~ifi into 62.61 grams water cn-~ g 1.6 grams Agrimer~9 VA-6. An ~mnl~ion was formed at high shear with a Waring blender. To the ~mnl~inn, after 1 min. of shear was added 5.56 grams of 43.37% h. ~ hy~ .--inç. After an ~d-litiQn~l 15 min. of slow shear stirring the forrnnl~tion was bottled. Discreet, individual mi loc~ .-lçs 1-15 microns in 20 ~ meter were obse~ sco~:cally. The f(~rmnl~tion r~m~ined fluid and readily r~i,u;,~ended with time.
~XAMPLE 7 This r~ shows mi ~ tion of aliquid cineole herbicide, ~inmethylin, with Agrimer~9 DAQ-2000.
80.00 Grams of r;.. ~ll.yL~ co.~ 5.56 grams PAPI~) 2027 was ~mnlsi into 62.61 grams water co~ i..;..g 1.6 grams Agrimer~D DAQ-2000. An emulsion wasformed at high shear with a Waring blender. To the ~m~ ion, after 1 min. of shear was added 5.56 grams of 43.37% 1-- ~ ylen~qtli~min~ After an ~ lhinn~l 15 min. of slow shear stirring the form~ tinn was bot~ed. Discreet, illdividual microc~ ..les 1-50 30 microns in diameter were observed microsc(,l~ically. The form~ fion rom~in.~tl fluid and readily r ,u~lded with time.
FXAMPLE~ 8 This F~mrle shows micro~ tion of aliquid cineole herbicide, cinmethylin, with Agrimer~ DAVC.
80.00 Grams of einmethylin co.. ~ g 5.56 grams PAPI~9 2027 was em~ ifie~
into 60.21 grams water co.~lA;~ g 4 grams Agnmer~) DAVC. An emulsion was formed at high shear with a Waring blender. To the ~mlll~ion, after 1 min. of shear was added 5.56 gr~ms of 43.37% h~ methyll .~iA...ine After an ~d-lition~l 15 min. of slow shear Wo 94/13139 PCTIUS93/11~23--Z1~092û
stirring the fsrmnlAtion was bottled. Discreet, individual microc~rsn1~s 1-10 microns in were observed mic~osco~ically. The formnlAtisn rtom~inP~l fluid and readily resuspended with time.
The following P.~mrles X and Y illllctr~tP advantages of the invention in various S solvents even though they are carried out in the abse.lce of any pçstiCi~ gl~di~ nl.
~:7.~AMPLE X _7,'' ."
This P~mrle shows micro~nc~rsnl~tion of a high density organic solvent, chlolurol,l.~ with Agrimer~9 DA-10 as çmlllcifiPr 90.00 Grams of chloror~ co~ g 5.56 grams PAPI~ 2027 was Pmlllcifi~d into 60.21 grams water co~ g 4 grams Agrimer~ DA-10. An emulsion was formed at high shear with a Waring blender. To the ~mnlcion~ after 1 min. of shear was added 5.56 grams of 43.37% l.~ ell~ylf.~rAiA~in~. After an a(l~lition~l 15 min. of slow shear stirling the formnl~hon was bottled. Discreet, individual mi~;ruca~ules 1-5 microns in metpr were obsel~ed microsco~:caUy. The formnlAtion 1~ r(l fluid and readily 15 l~i,u~nded widl time.
FX~MPLE Y
This P~mrle shows mi~ir~f .~A~ tion of a low density organic solvent, tolll~ne, with Ag~ 9 DA-10 as Pmnlcifi~r 80.00 Grams of toluene cc...li.;..;..g 5.56 grams PAPI(~9 2027 was ~mnlcifi~d into . 20 60.21 grams water ccl~lA;~ p 4 grams Agrimer~) DA-10. An ~mlllsi~n was formed at high shear with a Waring blender. To the ~mnl.cion, after 1 min. of shear was added 5.56 grams of 43.37% 1~ .yll -~rcli~ in~. After an a~l-liti- nAl 15 min. of slow shear stirring the formnl~tiolt was bottled. Discreet, individual microca~ules 1-20 microns in mçt~ .r were observed mi~;rosco~ically. The formnl~tio~ "S~ ç~ fluid and readily resuspended with time.
~X AMPLE 9 This P.~mrle shows miclu.,-~c^~ tion of a fimgi~ ç snlntion in organic solvent, with Agrimer~9 DA-10 as P.~ r 80.00 Grams of fln~ 7ole in ~ylene ~50%) co. ~ g 5.56 grams PAPI@D 2027 was ~m~ ifi~rl into 60.21 grams water conl~ ng 4 grams Agrimer~ DA-10. An emulsion was formed at high shear with a Waring blend~r To the ~mlll~ioll~ after 1 min.
of shear was added 5.56 grams of 43.37% hlos~methylen~ min~. After an acl-lition~l 15 min. of slow shear stirring the fc-rm~ tion was bottled. Discreet, individualmi.;ruc~ ..les 1-10 microns in li ....ct~ . were observed miclûsc~;_aUy. The formlll~tion 35 rom~in~(l fluid and readily l~u~lded with time.
This Fs~mrle shows mi~u~ cAl~ tion of a liquid cineole herbicide, ; ....cllylin, with AgnmerQ DAQ-2000, as ~mnl.~ifi~r, producing a polyester shellwall.
wo 94~ul3g 2 1 S O 9 2 0 PCTIUS93/11523 80.00 Grams of cinmethylin CO~ 17.77 grams s~acoyl rhlori-ie was emulsi~led into 60.21 grams water co.~ .;ug 4 grams Agrimer~ DAQ-2000. An ~-mlll.cion was formed at high shear with a Waring blender. To the ~m~ ion, after 1 min.
of shear was added a solution co~ g 6.33 grams 1,6-h~ rrliol~ 1.71 grams 1,3,5-b~ ;ol, and 12.00 grams 50% aqueous NaOH. After an ~rlrlition~l lS min. ofslow shear stirring the form~ tion was bottled. Discreet, uldivi~ual microc~rsules and some irregular shaped micn~c;~ les 1-50 microns in ~ metP.r were observed mi ;lusco~ically. The form~ tilm r~-m~inP~l fluid and readily ~ le~l with time.
~MPLE 1 1 This F.~mrle shows mi;lo- ~r~ tion of aliquid cineole herbicide, ~inmetllylin, by in situ mi~ ca~ tion, with Agrimer~ DA-10 as Pm~ if i~r.
200 Grams of ~inmethylin c~ .;..g lS grams PAPI~) 2027, lS grams of toluçnP-liiso~;y~lale, and 0.1 grams of dilJulyllill rlil~llr~tP, catalyst, was emnl~ifie~ into 154 grams water co.-l*;~ g 6 grams AgrimerlM DA-10. An em~ ioll was formed at lS high shear with a Waring blender for S min. The ~ 't was raised to 50C, and slow shear co~ e~3 for 1 h. Discreet, individual micr~c~ lPs 1-7 microns in ~ mete.r were obs~v~d miclosc-,~;c~lly. The formnl~ti~ n rPm~inP~i fluid and readily lt;su~ended with time.
ThisF~mrleshows llli~;lU -~rs~ tionofaliquidcineoleherbicide, ~-inm~thylin, with Agrimer~ DA-10 as PmlllcifiPr, ~lodu~lg a mixed ~olyul~afpolyamide shell wall.
80.00 Grams of f ;-----ell.yLl c~...li~;..;.~g 2.8 grams PAPI~) 2027, 1.4 grams s~bacoyl rhlr~ri~le, and 1.2 grams ll~uesoyl ChlQritlÇ, was ~mlllcifiç~ into 60.21 grams 25 water c~ ;..;.-g 4 grams A~i,~ ~ DA-10. An Pmlllcion was formed at high shear with aWaring blender. To the Pmlllcinn, after 1 min. of shear was added a solution c-,..l~;..;..g 7 grams of 43.37% hP~methyle.~ inP, and 2.5 grams 50% aqueous NaOH. After an ~d~lition~l 15 min. of slow shear stirring the fonn~ tion was bottled. Discreet, individual micloca~ules 1-10 microns in ~ -" t~ were obs~ d micloscu~ically. The forrnul~tion 30 rPm~inPcl fluid and readily l~i~U~. ..ded with time.
TITLE
MICROCAPSULE FORMULATIONS OF AGRICULTURAL CHEMICALS
P~ACKGROUND OF THE INVENTION
The present invention comprises novel compositions and processes directed to S the p~c;pa dlion of microcapsule formulations cont~inin~ random co- or ter-polymers of vinyll,yllolidone as an em~ if ier to form an oil-in-water emulsion.
U.S. 4,208,833 teaches the use of lignosnlfonates as useful emulsifiers for highconcentration microenr~rs-ll~tPcl formulations. However, the microcapsules settle out and illevt;l~ibly pack in the bottom of spray tanks and in spray lines upon dilution with water. In contrast, the microcapsules of the present invention, which comprise a novel type of emnlcifier, readily resuspend upon dilution with water.
SUMMARY OF THE INVENTION
This invention comprises a composition comprising a highly conl ç~ ed rnicroencapsulçd active pesticic1P suspended in an aqueous liquid, said microPnç~rsuhPd pesticides comrri~in~ a liquid, melted solid or solution of an active pesticide in an unreactive water-immiccible solvent within an encapsulating wall of polymeric m~tPri~l wherein:
(a) said active pesticide being present at a concentration ranging from about 480 to about 700 grams per liter of composition;
(b) said en~rs~ tin~ wall of polymeric m~tçri~l is the reaction product of a first shell wall colll~onellt which is a flifunrti~nal or polyfilnrtion~l reactant soluble in the active Festicicle, and a second shell wall co~ ollenl which is water-soluble and which is a difunctional or polyfiln-~ti~ n~l reactant and wL~l~in the concentrations of said first and second shell wall colll~onents are from about 3.5% to about 21.0% and from about 1.5%
to about 9.0%, respectively, by weight relative to the weight of the active pesticide tQ be enc~rsul~tçcl; and (c) said aqueous liquid is water co".~ g (i) from about 0.5% to about 15% by weight of an em~ ifiPr relative to the weight of said active ingredient to be çn~arsnl~tPIl, said emnl~ifiPr being a water-soluble random co- or ter-polymer of vhlyl~yllolidone, and (ii) optionally, from about 0.01% to about 30% of a formnl~tiQn adjuvant based on the total weight of the colllposilion.
This invention also comprises a process for pr~pa~ g a highly concentrated composition of particles of a microPnr~rslll~ted pesticide in water whe.chl the pestici~l~P.
is encapsulated in a plastic shell with subst~nti~lly no agglomeration of the particles, said process col"r~ lg ~cj~
21S~9~ D
(a) mixing a water-immiscible monomer A and an active pesticidal ingredient, in the form of a liquid, melted solid or solution of said active ingredient in an unreactive water-immiccible solvent, said monomer selected from the group consisting of diacid and polyacid chlorides, dichlorof~rm~tPs, polychloroformates, disulfonyl and polysulfonyl chlorides, diisocyanates, polyisocyanate and mixtures thereof, to form a solution of monomer in the active ingredient;
(b) dispersing in water cont~inin~ an emnlcifiPr~ the solution of the monomer and active ingredient, said emlllcifier being a water-soluble random co- or ter-polymer of vinylpyrrolidone, to form an oil in water emulsion with droplets in the size range of 1 to 100 microns;
(c) adding to the emulsion of (b) a water-soluble monomer B which will react with monomer A by intr.rf~ri~l polycon-lçn~tion to form a shell around the pestici~
ingredient, said water-soluble monomer B selected from the group cnncicting of ~ minP.s or polyamines, diols or polyols; or ~ iv~ly when monomer A is a diisocyanate, a polyisocyanate or mixtures thereof, optionally including a catalyst in the solution from (a) and heating the emulsion of (b) to hydrolyze monomer A to amine groups wl~ eby the amine groups generated by hydrolysis react with residual isocyanate monomers to generate a shell wall of polyurea;
(d) optionally, adding formlll~tion adjuvant(s); and (e) optionally, drying followed by granulation of the solid residue to form a flowable solid composition.
Dl~TA~T F.n DESCRIPTION OF T~TF T~VENTION
This invention conl~lises compositions cont~inin~ and processes for producing small or minute c~psllles con~ g a water-immi.ccible active pestir,i~r. By a process called interfacial polycon-l~n.c~tion, a monomeric first shell wall co.l.~?onellt (monomer A) is dissolved in a water-imrniscible active pesticide, or solution thereof. The resultin~
solution is l1i.cpçrced in water co~-t~;..i~-g an emulsifying polymer sçl.octed from co-polymers or ter-polymers of polyvinyl~yllolidone (PVP) to form an oil-in-water (O/W) emnlcit~n. Thel~,drt~,r, a second mon~ m~ric shell wall component (monomer B, usually 30 dissolved in additional aqueous phase liquid) is added to the oil-in-water emulsion whereby the second shell wall colllpol enl reacts with the first shell wall colll~ollent to form a polycoll-lenc~te shell wall about the water-immi.ccihle pestiCi~l~ at the oil/water intrrf~r.e High concentration :~u~pæ~-.cions cont~ining a larger volume of pçstici(le co~ onenl~ inside the microcapsules than the volume of water suspending the 35 microcapsules, are produced by interfacial polycon~lrnc~tion.
In some inct~nres, the second shell wall forrning co---~ollenl is u~m~çs.s~y. By a process called in situ microçnc~ps~ tion, isocyanate monomers are dissolved in the water-imrniscible active pçsticid~l ingredient, and the solution is dispersed in water co~ g A~EN~ED ~1 ,. ~ 21509~0 an emulsifying polymer selected from co-polymers or ter-polymers of vinylpyrrolidone.
Amine groups generated by hydrolysis reaet with residual isoeyanate monomers, generating a shell wall of polyurea. A eatalyst that will speed the hydrolysis of the isocynate may be included in the monomer in the active ingredient solution. These are S well known in the art. One such catalyst is dibutyltin dilaurate. Heat is applied to also speed the hydrolysis. Generally, when a catalyst is used a telllp~,ldLule of 20 to 60C is sufficient to carry out the hydrolysis in one hour. However, if the catalyst is not used a temperature of 58-75C will require several hours, e.g., 12 hours for the hydrolysis.
Microencapsulation is especi~lly useful for making high concentration solid 10 formulations of liquid pesticides. Without microencapsulation, unencapsulated liquids must first be absorbed onto inert carriers to create dry powders which can be gran~ tçd to dry solid water-dispersible form~ tions. With large amounts of inert earrier required to absorb liquids, solid dry formlll~tions of llnP.nl~ps~ t~P~ liquids are nPcçcs~rily dilute.
Without micloenca~ultation""~xil"..." qu~ntitiP~ of unPn~psulated liquid in dry solid 15 form~ tions is about 40%. By contrast, microcapsules contain at least 90% liquid and ean be form~ tPrl to dry solid forml-l~tion~ whieh may eontain more than 70% liquid pestieide.
Once enc~ps--l~tP~i, the liquid or other form of the aetive pestieide (e.g., meltable solids) is preserved until it is released by some means or hl~llul~ nLality that breaks, 20 erushes, melts, dissolves, or otherwise removes the eapsule skin or until release by diffusion is effeeted under suitable eonditions. Mieroçn~ ~ps~ tion reduees aeute toxieity of pçstici-l~e, improves biological efficacy, may reduce l~chin~ into groundwater, and ean isolate in~ompatihle pestieides from eaeh other within the same f~rmlll~tion.
Despite these advantages, mieroenrars~ tion is not e~Lèll~ively utilized beeause25 early proeesses produeed dilute eomposiLions. Colloid stabilizers utilized to (li~pçrse the oil phase are erre ;Live only if the conLilluous aqueous phase is a larger volume than the pP~ed oil phase. When colloid st~bili7Pr~ are utilized for high con(~çntr~tion microen~ tion, microcapsule aggregates are produced.
We have diseovered that eertain eml-l~ifier~, random eo-polymers and ter-30 polymers of vinyl~yllolidone, ean he advantageously used in the process ofmieroenrarsul~tion using an interf~ei~l polyeontl~Pn~tion reaetion bGlwGen reaetivemonomers within the oil and water phases, or in the proeess of in situ mieroeneapsulation with isoeyanate monomers eontained in the oil phase. After dilution into water the settled mierocapsules prepared by these proeesses are readily resuspended 35 and do not aggloll~ dle. The present invention provides new elle~rs~ tion proeesses whieh are erÇe-;tiv~ to ~ te high conccll~dlions of water-immiseible agrieultural produets to provide high eoneentration sl~spçn~ions of mierocapsules, or dry dispersible formulations ~ a~cd by drying and gr~n~ ti~n of the rçs--lting solid mic,-,cdl,~lllçs 21~0920 A critical feature of the present invention is the use of the specific type of emllleifier~s to form sufficiently stable oil-in-water emulsions so that a concentrated amount of active pesticide is present in the water-immiscible phase and is therefore encapsulated. Generally, there is greater than 480 grams of active pesticide or active 5 pesticidal solution per liter of total aqueous composition. Dry solid formulations contain greater than 70% liquid water-immiscible m~teri~l in dry water-~ pereihle form.
The microcapsules of the present invention may contain dyes, inks, chemical agents, ph~rm~reuticals, flavoring materials, pesticides, biological agents, plant growth regulators, and the like. Any liquid, oil, meltable solid, or solvent soluble m~tPri~l into 10 which shellwall monomers can be dissolved and which are nonreactive with tne monomers may be encapsulated.
In the practice of the preferred embodiment of the present invention, the m~teri~l to be enr~ps~ tPd is a water-immiscihle active pesticide. As in-lic~tPd above, the active pesticide is any liquid, oil, or meltable solid, to which the first shellwall monomeric 15 co~ ollent is unreactive. In addition, a water-immiscihle active pesticide can colll~lise a solution of an active pesticitle in an unreactive water-immiscible solvent.
The active pesticide is selected from the group consisting of herbicides, in.secticides, acaricides, fungicides, nematocides, bactericides, biological pest control agents, herbicide safeners and plant growth regulants. Examples of suitable a~ri~lllhlral chPmi~le include:
20 herbicides such as acetochlor, aciflllorfen, alachlor, asulam, atrazine, beneulfilron methyl, bentazon, bromoxynil, butachlor, hydro~yl~nzollillile, chlola llben, chlolilllulùil ethyl, chloroxuron, chlorsulfuron, chlorotuluron, clomazone, cy~n~7inP, dazomet, l~PsmP~lirhan, ~ mb~ dichlorbenil, dichlorprop, diphPn~mitl~ diplù~ yll, diuron, thi~lllr~ un~ fenac, fluolllt;lulvn, fluridone, folllPs;~r~i-, gly~hos~Lt:, im~7~mPth~benz,5 imazaquin, hllazelll~yl, ioxynil, iSOpÇulurOII, isouron, isoxaben, karbutilate, tr~ t~
tP~, triflllr~lin, linuron, lenacil, MCPA, MCPB, mPfluitli-le., metha~e~ llron~
mPth~7olP., mPtol~hlor, metribuzin, mPtelllfilron methyl, monuron, n~pt~l~m, neburon, nitr~lin, nolnuld~on, oryzalin, perflllidonp" phel.l,,P~lirh~ plulll~llyll, plu~ e~
pl~azil~, ~yldzon, rimsulfuron, siduron, eim~7ine, sulrùlll~lul~on methyl, tebu~ulon, 30 terbacil, telbu~lylazine, telbullyll, triclopyr, 2,4-D, 2,4-DB, tri~eulfilron~ tribenulo methyl, primieulfilron~ ~y-,17o~ulfilron ethyl, N-[[(4,6~1imP,thoxy-2-wrimidinyl)amino]carbonyl]-3~ethylsulfonyl~2-pyridine-sulfon~mide, nicosulfiuron, 2'-t-butyl-2-chloro-N-methol~ylll~lllyl-6'-methyl~ret~nilidP, oc-chloro-N-(2-methoxy-6-1llt;lllylph~,llyl)-N-(1-methyletho~ylllcilllyl)~et~mi-l~P-, a-chloro-35 N-(etho~ylll~lllyl)-N-[2-methyl-6-(trifluorolllt;l~lyl)phenyl]~et~mi-le, a-chloro-N-methyl-N-[2-methyl-6-(3-methylbutoxy)phenyl]~et~mid~P, a-chloro-N-methyl-N-((2-methyl-6-~J, ~ 2150920 propoxyphenyl)~et~mide, N-(2-butoxy-6-methylphenyl)-oc-chloro-N-methyl-~cet~midç, isobutyl (2,4-dichlorophenoxy)~cet~te, 1-(1 -cyclohexen- 1 -yl)-3-(2-fluorophenyl)- 1-methyl urea, and ethametsulfuron methyl; fungicides such as carben(l~7im, thil-r~m, dodine, chloroneb, cymox~nil, captan, folpet, thiophanate-methyl, thiabendazole,S chlorothalonil, dichloran, captafol, iprodione, vinclozolin, k~cug~mycin, thi~-limPnol, flutriafol, flllci1~ol, hexaconazole, and fenarimol; bactericides such as oxytetracycline dihydrate; acaricides such as hexathizox, oxythioquinox, dienochlor, and cyhP~tin;
incectici~lPs such as c~l,or~lldn, carbyl, thiodicarb, delt~mpthrin~ methyl and ethyl parathion, pyrethrin, permethrin, fenvalerate, and tetrachlorvinphos; and herbicide 10 safeners such as 5-thiazolecarboxylic acid.
The m~tPri~l to be encapsulated need not consist of only one active pesticide, but may be a combination of two or more active pesticides. For example, such a combination may be a herbicide with another active herbicide or a herbicide and an insecticide. Also cun~ lplated is a water-immicçihle m~teri~l to be encapsulated which 15 comprises an active ingredient, such as a herbicide, and a non-pesticidal ingredient such as an adjuvant or inert m~tçri~l to achieve some special plo~~
The water-immiccihle active pesti~ P when in liquid form may act as the solvent for the first shellwall component, or espeçi~lly when the active pestici-le is a solid, the use of a water-immiscible organic solvent such as methylene chloride, ~lk~nPs, benzene, 20 toluene, xylenes, etc., may be used. The use of a liquid active pesticide without additional organic solvent allows for a concentrated amount of the active pesticide in the final en~rs~ tPd product. The water-immi~ihle active pesticide and first shellwall colll~ollent are added cimlllt~n~ously to the aqueous phase in a pre-mixed state. That is, the water-immiscible m~teri~l and first shellwall component are pre-mixed to obtain a 25 homogeneous organic liquid phase before addition to, and emulcifi~tior~ in, the aqueous phase to form the oil-in-water emulsion.
The concenl-dlion of water-immi~cihle active pçsti~ide initially present in the water-immiscible phase should be sufficient to provide at least about 480 grams of water-immiccihle active pesticide per liter of total aqueous composition. In practice, as 30 is recognized by those skilled in the art, the use of e~ llely high concentrations of water-immiccihle active pPstici~le results in undPcir~hly thick ~u~nsions of microc~pslllPs. In general, the concentration of water-immiscible active pesticide ranges from about 480 grams to about 700 grams per liter of total aqueous composition. The preferred range is from about 480 grams to about 600 grams per liter of total aqueous 35 composition.
The shellwall of polycon-lPnc~te may be a polyurea, polyarnide, polysulfon~mi-le, polyester, poly-,~bollah, polyurethane or mixtures thereof. The following are specific inct~n~es of polycon~l~Pnc~tion reactions to which the present en~ tion process is applicable. Di~mines or polyamines in the water phase react with diacid or polyacid chlorides in the organic phase liquid to yield capsule walls co,~ ; of polyamides.
Diamines or polyamines ill the aqueous liquid cnn-len.~e with dichlororo. ., .~t~s or polychlorl,rJ l..~t~Ps in the organic liquid to form a polyul~,ll~ capsule skin. Di~mines 5 or polyamines in the a~lueous liquid react with disulfonyl or polysulfonyl chlorides in the organic liquid to produce apolysulfon~mide capsule skin. Di~mines orpolyamines in the aqueous phase liquid and a dii~o-;yallale or polyisocyanate in the organic phase liquid react to form a polyul~ a skin. With diols or polyols in the aqueous liquid and diacid or polyacid ~ hlori~lP~ in the organic phase liquid, polyester shellwaUs are produced. When 10 bischloluru....~t~s orpolychlc,rùf ....-:-t~s are used in the organic liquid, the capsule skins are polyc~l,ollalcs.
It will further be a~ ,cialcd that not only are there other complemPnt~ry intPrmetli~tes which react to form polyco~ ,5 in a manner useful in the intPrfa~
polyco~ si~l ;on ~locess of ~ tion, but various ll~ Ul~ s of intermediates, i.e., 15 l~ Ul~ s of shellwall cc""~one,lls, may be employed in either or both of the aqueous and organic phases. For P~mrle, mi~ctures of diols and ~1;;..ll;l~F~ in the aqueous liquid and acid ~hlori-1~(s) in the organic liquid are useful to achieve pol~,,t~olyamide con-~ l ;o.~ copolymers. Also, ~ min~s or polyamines in the a4ucuus liquid and llliAlUl~S of diacid or polyacid chlorides and di~ocy~lat~ s or polyiso~;y~les in the 20 organic liquid produce a polyamide/polyurea skin.
F.~mrleS of suitable l;r....~ acid-derived shellwall components suitable as monomeric colllpol,~ s for the organic phase are s~bacoyl chloridP" ethylene bischlolurc.. ~te, rhosgP.nP~, t~ )hlh~loyl ~hlori-lP., adipoyl .hlori-le, azelaoyl r.hlori~lP.
(azelaic acid chl~ rirle), dodec;~ ;oic acid chloride, dimer acid çhlori-1P~, and 1,3-25 be .~ F,~ fonylrlirhloritle Polyfilnt~tion~l co",~oul~dsofthis~h; .i-~t~ . areP~rPmrlifi by trimesoyl chl--ritle 1,2,4,5-b~ ~ nc tetracid chloritl~P, 1,3,5~ f trisulfonyl chloride, tnmer acid r~hlori(le, citric acid rhloritle, and 1,3,5-l~ ne tri.sçhlolurol",ate.
Monomers similarly useful in the organic phase include diisocy~,al~s and polyiso~;yallaL~s" for e~cample, toluene diiso~;y~,ate, h~methylene diiso.;yal~dle, 30 methylene dipll~llyliso~-y~l~e and poly,.,~,ylene poly~l,ellylisocyanate.
F.~mrles of suitable diols for use as monomers in an aqueous phase are bisphenol A [2,2 bis-(p, p'-dihy~uAy diphenyl)pluL)~le], hydro4uil,one, l~so~ ol, catechol, and various glycols such as ethylene glycol, ~...~ iol~ hP~n~-~liol, do-lec~.-ftliol, l,~bllt~ne~ l and the like. Polyfimt~tion~l alcohols of this character, e.g., 35 triols and polyols, are PYPmrlifiPcl by pyrogallol (l,2,3-1;~ -->f ~ ;ol), phlorogl~lçint-l dihydrate, pentae.y~ ilol, trimethylol~;lv~anc, l,4,9,10-tetrahyd,u~ya.~ cenc, 3,4-dihycllu~y; ..1l.t~ 01, dil~sorcillol and tetrahy~Lu,~y~ ;..on~
~ 21~09~D
Suitable ~ minPs and polyamines for use as monomers in an aqueous phase, usually selected as water-soluble per se or in water-soluble salt form, are ethylene minP, phenylene ~ minP, toluene ~ minP, hexamethylene ~ minP, diethylene tri~minP
and pipe.azille. Amines which are effective as polyfunctional re~ct~nt~, are, e.g., 1,3,5-S benzene tri:~minP trihydrochloride, 2,4,6-tri~mino toluene trihydrochloride, polyethylene imine, 1,3,6-tri~min~narl~ lPn~, 3,4,5-tri~mino-1,2,4-triazole, melamine, and 1,4,5,8-tetramino anthraquinone. Amines which have greater than 2 but less than 3 amine functionalities and which may provide a degree of cr s~linking in the shellwall are the polyalkylene polyamines of the type R R
H2N(CH2)mCH--HN(CH2)nCII NH2 wherein R equals hydrogen or CH3, m is 1-5 and n is 1-5, e.g., tetraethylene ~,~pentaethylene hexamine, and the like.
In intPrf~ l polycon-l~n~tion, the amount of first shell wall co~ onenl and second shell wall component used in the process determinPs the percent shell wall content produced. Generally, there is present in the reaction from about 3.5% to about 21.0% first shell wall component, and from about 1.5% to about 9.0% second shell wall component, relative to the weight of the water-immiscible m~t~ri~l A stoichiometric amount or excess of second shell wall component may be used. The shell wall content of the capsules which results varies from about 5% to about 30%, preferably 8 to 20% and more particularly, 10% by weight, based on the weight of the active ingredient to be 20 encapsulated.
Represenl~ti~. of isocyanate monomers suitable for in situ micr~en-~ps~ tion are the following: 1-chloro-2,4-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 2,4-tolylene diisocyanate, tolylene diisocyanate (60% 2,4-isomer, 40% 2,6-isomer), 2,6-tolylene 25 diisocyanate, 3,3'-dhll~ yl-4,4'-biphenylene diisocyanate, 4,4'-methylenbis(2-l,wlllylpll~llyl isocyanate), 3,3'-dimethoxy-4,4'-bi~hellylene diisocyanate, 2,2',5,5'-le~ hyl-4,4'-biphel,ylene dusocyanate, 80% 2,4- and 20% 2,6-isomer of tolylene diisocyanate, poly",~lllylene poly~henylisocyanate (PAPI(~), and llli~ures thereof.
The amount of organic polyisocyanate used in the in situ micr~ n~r,~ tion process d~ s the shellwall content of the c~ps--les formed therein. The preferred range is from about 5.0% to about 30.0% relative to the weight of active pesticidal ingredient to be e~ ul~t~d Most ~r~fe,l~d is about 10% relative to the weight ofactive ingredient to be en-~ps~ t~l 21~0920 What is meant by an emulcifier is a copolymer or terpolymer of vhlyl~yllolidone wherein the vinyl~yll~ lidone is present in sufficient amount to provide the copolymer or terpolymer with the properties described below. The emnlcifierc of the invention are copolymers and terpolymers composed of any non-aromatic water soluble monomers polymerized with vinylpyrrolidone to produce water soluble copolymers and terpolymers which are capable of forming a stable oil-in-water emulsion under the reaction conditions described herein. Any polymer combination which includes s--fficient vinylpyrrolidone to render the whole polymer combination to be water soluble is expected to be useful as an emulcifier of the present invention. This includes copolymers, terpolymers of vinylpyrrolidone wherein the copolymer and terpolymer includes any number of different polymers in combination with vinylpyrrolidone that results in the copolymers andterpolymers being water soluble and capable of producing a stable oil-in-water emulsion under the present conditions. ~le~ell~d copolymers include VP copolym~qri7~d with 1) vinyl acetate, 2) dhllt;Lllylalllinolll~llylln~ rylate, and 3) qu~~ d dimethylaminoe~lyl",r~ crylate. The weight percent VP in the copolymers is 20 95%, preferably 50-85%. Preferred terpolymers include VP copoly~ ed with capr ll~ct~mand dimethylaminomethacrylate. The weight percent VP in the terpolymers is 10-80%, preferably 15-50%. Specific c~ l~r~ially available VP copolymers are Agrimer~
DA-10, Agrimer~ DA-1, A~lhlle.'~) DAQ-300, Agrimer0 DAQ-2000 and Agrimer~
VA-6. Agrimer~9 DAVC is lepleselllaliv~ of terpolymers which are also effective for use in practice of the invention. These polymers are m~nllr;~ ed by Tntern~tional Specialty Products, 1361 Alps Road, Wayne, New Jersey, 07470. Preparation of these polymers is described in U.S. 4,520,179; U.S. 4,520,180; U.S. 4,554,311; U.S. 4,554,312; U.S.
3,691,125; and U.S. 4,521,404.
The range of emnlcifier concentr~tion found most acceptable in the system will vary from about 0.5% to about 15% and preferably 2% to 6%, based upon weight of the active ingredient to be er-c ~ps~ ted The micloca~ules of the present invention require no additional tr~tmP-nt such as separation from the aqueous liquid, and may be directly lltili~Pd The aqueous~us~llsions are suitable for many applications depending on the water-immi~ihle m~teri~l which is en~rsnl~te(l For çx~mrle, an aqueous sllcpencion of Illis~ lçscont~ining a herbicide may be combined with liquid fertilizers, insecticides, or the like to form aqueous solutions which may be conveniently applied for agri~ultllr~l uses.Often it is most convenient to bottle or can the aqueous ~ l~n~ion cont~ining the enr~psul~ted water-immiscible m~tt?ri~l in which case it may be desirable to add formlll~ti~n ingredients to the aqueous solution of microcapsules. Formul~tion adjuvants such as density balancing agents, thie~n~rc, biocides, sllrf~rt~ntc, .li~ "lc, salts, anti-freeze agents, and the like can be added to i-..~ ve suspension stability and the ease of AMEND~D SHFET
21~()920 Wo 94/13139 ^ PCT/US93/11523 applic~tit n If a formnl~tioll adjuvant is added to the aqueous ~u~ensivl of microc~ules such ingredients are ~lGr~ably added at a conc~ ;o" of from about 0.01% to about 30% by weight of the su~ension.
If it is desired to adjust the pH of the ri.~i~l.rd miclocAp~ formnl~tion as, for S ~mple, when the aqueous solution of fini~hf d mic;rvca~ule is cnmbin~-l with other pestic~ s, con~ n~l reagents for ~.lj.-~l-..~ -l of acidity or ~lk~linity, may be used.
For ç~mple, suitable snb~ ce,s are hydrochloric acid, sodium Ly~llvAide~ sodium c~l,on~le, and sodium bicaLl,vll~le.
Thus the pçsticitl~l col,l~vsilion may be in liquid form co...l.. ;si.-g the su~nsio 10 which results after the microf -~p~ tion re~ction ~ I;v~;ly~ the pesticidal composition may be in solid form by drying the ~u~ension which results after microf .~r~ ti-)n and then gr~mll~tin~ by using well-known techniques to afford a dry microencapsulated granule cvlll~osi~ion.
In pr~cticing the ~rvcess of the present invention, the ~ e.a~ult; should be 15 m~;, ll~;llf ~1 above the melting point of the pesticide if used neat, or the unreactive solvent if a pesticide solutiolt is used. The t~,l*e.~lul~; should also be kept below the point at which the water-immi~r-i~le monomer hydrolyzes or olllt,.wise clçco,..l)oses. For example, where it is desired to e~ "l~t a solid herbicide wi~ ul solvent, it will be llf cçss~y to heat the herbicide to its molten state. Alachlor herbicide, for e~ample, mdts at 39.541.5C and the l~,."~tur~ of the process should ~ccor~l;,.gly be m~ Fd above about 41.5C.
The~g;t~l;o,-employedto~st~hli~hthe.l;~ ;ol-ofwater-;....~.is~;l,ledro~ sin the a~ueous phase may be supplied by any means capable of providing suitably high shear. That is, any variable shear mi~ing a~al~lus, e.g., a hl~nd~r, a homogenizer, etc.
25 can be employed to provide the desired ~git~tinn The p~rtir~ r size of the microc~pslllçs will range from about 1 micron up to about 100 microns in ~ me.tr.r. A ~rt~l~t_d range is about 1 to about 50 microns. From about 1 to about 10 microns is an optimum diameter range.
The present invention is further explained by the following F~mrl~s which are 30 ;11~ I;VG and not limiting in nature. Unless uLh~,w~sc in~ te~lJ the int~rf~ri~l polycon~l~n~tio~ F.~mplçs which follow were ~- ru....erl as follows: thé water-immi~rihle m~teri~l, co,~l~;";"~ the first shellwall colll~ollelll(s) dissolved therein, was emnlcifiçd into water co,~ the rm~ if içr; the emulsion was formed with the aid of high shear. The second shell wall coll~un~ (s), usuaUy dissul~ d in an ~ ition~l35 amount of aqueous phase liquid, was ~ c~l~,ï added to the ~m~ ion and after a short period of time, the shear rate was re~lllce~l She~r was contimled for varying periods of time and t~C~ L~ salt or a ~u~.ldillg aid was added if ..ecess~y to stabilize the suspension. The form~ ti~l~ was then bottled.
-WO 94/L3139 ~,~9~,~ PCT/US93/11523 --In the process of in situ microencapsnl~ti- n, the isocyanate monomers were dissolved in the water-immist ihle phase along with a catalyst. An çmnl~ion was made and slower shear was co~ -c~l and the te~ tUl~:; raised to speed the shell wall forming reaction. The shellwall component is formed by the reaction of the amine 5 hydrolysis product and residual isocyanate.
FX~MPLE 1 This F~mrle shows the use of Agrimer~9 DAQ-300 (vinyl-pyrrolidone/~ t~ 1 dil~ ylan~-o~ll-yl ...~ ylate co-polymer 300,000 molecular weight) to emulsify- an acet~nili-le herbicide at ele~ d t~ ulc for 10 microencapslll~tion 200 Grams of ~e~hnic~ rhlor (93.8%) Co.~A;";..g 13.9 grams of PAPI(~) 2027 (a polyll~ ylene poly~ .lyliso~iydn~ s from the PAPI series by Dow ~h~mit ~l CO1l1~J~1Y) was emulsified into 152.38 grams of water co.~ g 10 grams of Agrimer~
DAQ-300. All m~t~ri~l~ were m~;..l~;...o..~ at 50C. The t-mnl.~ion was formed with a 15 Waring blender ~.~ lg at high shear. To the emnl~ion, after 1 min., was added13.9 grams of 43.37% ht~methylL.~tli~...;..e and shear was reduced to a stirring shear.
After S min. of stirrin~ 32.8 grams of sodium chlori~le and 22 grams of 1% Kelzant~, a ~nth~n gum thi~ ner, were added. Stirring co.~l ;....e~l for 15 min. and the ft)rmnl~tit)n was bottled. Discreet spht-rit ~1 microc~rsnles 1 to 40 llliClUnS in tli~mett.r were 20 observed microscù~ically. The form~ tion was stable through acc~lt -~e-l aging at 54C
and after several weekly IC~ U1C cycles b~ &l -4 and +54C.
l~XAl~LE 2 ~ is E~ample shows micro- -~A~ ti~n of ~ hlor at ele~ted tc~ ulti using Agl~nOE~9 DA-10 (villyl~yllùlidone/dimelllyl;~linsethyl m~ ylate co-polymer) 25 as lom~ ifi~r 200 Grams of technic~ hlor (93.8%) co. ~1; ;. .;. .g 13.9 grams of PAPI(~) 2027 was emulsi~led into 152.38 grams of water co..li~;..;..g 6 grams of Agrimer~9 DA-10. All m~t~ri~l~ were m~int~ ~ at 50C. The ~mnl~if~n was formed with a Waring blender o~>el~i,lg at high shear. To the f mnl~ion, after 1 min., was added 13.9 grams of 43.37%
30 hexamethyl~ne(li~min~o and shear was reduced to a stirring shear. After 5 min. of stirring, 32.8 grams of sodium chloride and 22 grams of 1% Kelzan~, a ~nth~n gum thickener, were added. Stirring continned for 15 min. and the ff~rmnl~ti()n was bottled. Discreet h. - ;f ~l micl~,c~ules 1 to 50 microns in fli~mf,t~r were obs~,d micr~sco~ically. The formulation was stable through ~cc~ l aging at 54C and after several weekly L~ Gl~lUlG cycles btL~ ,.l -4 and +54C.
2I~0920 WO 94/L3139 PCT/US93111~23 F~MPLE 3 This F.~mrle shows miclo ~r~ tion of ~lArhlor at d.,~alt;d ~ alule using Agrimer~) DAQ-2000 (vu~yl~ylr~lidone/~ t -..~ e~llylamulG~lhyl ...clhA~ .ylate co-polymer 2,000,000 molçcnl~r weight) as rm~ if i~-r 200 Grams of terhnic~ rhlor (93.8%) co.~ 13.9 grams of PAPI(~ 2027 was em~ if i~l into 150.38 grams of water co~lAi~ 4 grams of Agrimer~) DAQ-2000.
All m~t~ri~l~ were m~;..l~;..Pd at 50C. The emlll~ion was formed with a Waring blender o~e~l..lg at high shear. To the Pmnl~ion, after 1 min., was added 13.9 grams of 43.37%
hexamethylc ~c~ in~ and shear was rç~lced to a sti~Ting shear. After S min. of stirring, 32.8 grams of sodium chloride and 22 grams of 1% Kelzan~, a ~nth~n gum thirl-rn~r, were added. StilIing co..l ;..-,ecl for 15 min. and the formnl~tion was bottled. Discreet ~h~ A1 micl~,cA~ les 1 to 25 microns in ~ metPr were obs~ ~ d microscopically. The formulation was stable through ~cc~ ,d aging at S4C and after several weeldy t~ll~ `t cycles b~.L'.. ~ n 4 and +54C.
~AMPLE 4 This F.~c~mple shows mi.;l~ c~ tion of ~l~rhlor at cle~,al~d t~.ll~lalult using AgIimer~ DAVC (villyl~y~ np~lvinylc~ yla-m meth~l~rylate ter-polymer) as çmnl~ifiPr.
200 Grams of t~h~ Al ~l~rhlor (93.8%) co.~ g 13.9 grams of PAPI~ 2027 was ~mnl.~ifi~l into 160.38 grams of water c~ g 8 g of Agrimer~) DAVC. All m~teri~l~ were mAi.~ at 50C. The Pmlll~ion was formed with a Waring blender o~ g at high shear. To the f-mnl.~ion, after 1 min., was added 13.9 grams of 43.37%
he~camethyl~ ...in~ and shear was r~luced to a stirring shear. After S min. of stirrin 22 grams of 1% Kelzan~, a ~..lh~. gum thi~ oner~ was added. Stirring continnecl for 25 15 min. and the formnl~tinn was bottled. Discreet s~ -- ;cAl microc~rs lles 1 to 15 microns in ~ met~r were ol)s~d miclosco~ically. The form~ tion was stable through accele al~d aging at 54C and af~er several weekly t---~ cycles l~l.. C~
-4 and +54C.
COMPARATIV~ EXAh~L~ A
30This ~.,..... p~.~live F~mrle shows miclu~ a~ tion of ~ hlor at elevated ~ll,U~,rall.Jlt; using Rea~ D 88B (a 1;~nO;j~1rU~ e P~ ;r;~ r).
200 Grams of te~hnir~ hlor (93.8%) co.~ g 13.9 grams of PAPI~ 2027 was emulsified into 150.38 grams of water co~ g 4 grams of Rea~9 88B. All m~teri~l~ were m~ at 50C. The .omnlsion was formed with a Waring blender u~e ~l~ng at high shear. To the em~ ion, after 1 min., was added 13.9 grams of 43.37%
hex~l,ethyk . .~ .. .in~ and shear was reduced to a stirring shear. After S min. of stirring, 32.8 grams of sodium çhlnri-le and 22 grams of 1% Kdzan~, a ~ gum th~ n~r~
were added. Stirring co"l;..-Je~l for 15 min. and the formnl~tion was bot~ed. Discreet WO 94/13139 ~ 1 5 0 91 2 ~ PCTIUS93/11523 --sph.ori~l microc~rs~ s 1 to 20 microns in ~ met~.r were ol)se.~,ed microsc~ically. ~he formulation was stable through acc~ fl aging at 54C and after several weekly GlllpGla~UlC cycles b.,~ 4 and +54C.
Rei,u~ dability of settled solids from diluted fnrmnl~tion~ prepared in F~mrles 5 14 and Coll~aLaLivG F~mrle A was tested as follows: Into 95 grams of tap water in Nessler(8) tubes was added S grams of the formnl~tion The Ne.,i,l~ tubes were inverted several times and shaken to thoroughly sùspènd the formnl~tion~ and then left nn~ ed for 3 days at room t~ll~ LulG. The~Nessler~ tubes were then slowly inverted and the number of inversions required to l~i,u~Gl~d the settled microc~psul~s 10 was recorded. Data are shown in Table 1.
T~RT.F, I
Number of Inversions P~çq ire(l to Rei,u~e,-d Settled Microcapsules after 3 Days FORMULATION F~ULSIFIE~R ~V~RSIONS
~xample 1Agrimer~9 DAQ-300 10 r~mrle 2 Agrimer~) DA-10 12 r~ 3 Agr~ner~9 DAQ-2000 4 ~ample 4 Agrimer~ DA~C 29 Comp. F~mrle ARea~) 88B >100~
~Requ~red vigorous shaking to , ' the settled l.~,lU~ v s We consider 30 ill~. ,~s to be the ,lally acc~l ' cut off.
COMPARA~ ~L~ B
This co )auaLive t~ mple shows aLh,..l~t~d micrG~ tion of alachlor at devated le.,l~l~tul~; using A~i..le~lD ST (v..lyl~yllolidone/styrene copolymer).200 Grams of terhni~ hlor (93.8%) co"~ 13.9 g of PAPI 2027 was ~mnl~ifi~-l into 152.38 g of water co.. ~ g 10 g of A~ 10 ST. All m~tçri~l~ were m~ rrl at 50C. The ~mnt~ion was fonned with a Waring blender o~ g h~ .ylen~ mint~ Upon~d~litionof~ mine~instantso~ fi~tionoc~ ,d. No useful microcd~ les were obtained.
E~LMP~.F 5 This E~cample shows microencapsulation of a liquid cineole herbicide, cinmethylin, with AgrQner~) DA-10.
80.00 Grams of cinmethylin co.~ g 5.56 grams PAPI~ 2027 was ~mnl~ifiçcl into 62.61 grams water c~ E 1.6 grams Agrimer~) DA-10. An ~mnl~ioll was formed at high shear with d Waring blender. To the ~mnl~ion, after 1 min. of shear was added 5.56 grams of 43.37~o hf~methyl~n~ mint~.. After an ~ 1itif~n~1 15 min. of slow shear stirring the form~ tion was bottled. Discreet, individual mi._.uci.l,s..l~s ~ ~15092~
WO 94/13139 ^ PCT/US93/11523 1-50 microns in ~ meter were obs~v~.d micr~sco~ically. The formnl~tinn r~m~ined fluid and readily l~,.,.~s~ .ded with time.
CC)MPAR ATrVE EX:AMPLE C
This ~Y~mrle shows the au~ t~ d micl~ tinn of a liquid cineole 5 herbicide, c;~ hylil~ with Agrimer~l9 ST (vi~lyl~yll~lidone/~Lyl~e copolymer).Fs~mrle 5 was l~al~l e~actly as dçs~ril~ed e~cept that 1.6 g of Aglil~ ) ST
was used in place of 1.6 g of Aglilll~0 DA-10. The ~mnl.~ion formed well, however, when ~ minP was added to the ~mnl~ion it became a pastey m~t~ri~l Micr~sco~icaUy it a~L)ca.~d that microc~rslll~s may have formed, however, they were highly ag~,l~hL~d 10 and the entire colllposi~ion was not a useful ~u~,ns;on of diSC~ ,l microc5 E3~AMPLE 6 This F~mrle shows micio~ tinn of a liquid cineole herbicide, t~inmethylin, with A~ .~ VA-6 (vil.ly~ylluli~lo~ /vinyl acetate r~n~lom copolymer having 60% pyrrolidone and 40% acetate by weight).
80.00 Grams of cinmethylin co~.~ g 5.56 grams PAPI~9 2027 was ~mnl~ifi into 62.61 grams water cn-~ g 1.6 grams Agrimer~9 VA-6. An ~mnl~ion was formed at high shear with a Waring blender. To the ~mnl~inn, after 1 min. of shear was added 5.56 grams of 43.37% h. ~ hy~ .--inç. After an ~d-litiQn~l 15 min. of slow shear stirring the forrnnl~tion was bottled. Discreet, individual mi loc~ .-lçs 1-15 microns in 20 ~ meter were obse~ sco~:cally. The f(~rmnl~tion r~m~ined fluid and readily r~i,u;,~ended with time.
~XAMPLE 7 This r~ shows mi ~ tion of aliquid cineole herbicide, ~inmethylin, with Agrimer~9 DAQ-2000.
80.00 Grams of r;.. ~ll.yL~ co.~ 5.56 grams PAPI~) 2027 was ~mnlsi into 62.61 grams water co~ i..;..g 1.6 grams Agrimer~D DAQ-2000. An emulsion wasformed at high shear with a Waring blender. To the ~m~ ion, after 1 min. of shear was added 5.56 grams of 43.37% 1-- ~ ylen~qtli~min~ After an ~ lhinn~l 15 min. of slow shear stirring the form~ tinn was bot~ed. Discreet, illdividual microc~ ..les 1-50 30 microns in diameter were observed microsc(,l~ically. The form~ fion rom~in.~tl fluid and readily r ,u~lded with time.
FXAMPLE~ 8 This F~mrle shows micro~ tion of aliquid cineole herbicide, cinmethylin, with Agrimer~ DAVC.
80.00 Grams of einmethylin co.. ~ g 5.56 grams PAPI~9 2027 was em~ ifie~
into 60.21 grams water co.~lA;~ g 4 grams Agnmer~) DAVC. An emulsion was formed at high shear with a Waring blender. To the ~mlll~ion, after 1 min. of shear was added 5.56 gr~ms of 43.37% h~ methyll .~iA...ine After an ~d-lition~l 15 min. of slow shear Wo 94/13139 PCTIUS93/11~23--Z1~092û
stirring the fsrmnlAtion was bottled. Discreet, individual microc~rsn1~s 1-10 microns in were observed mic~osco~ically. The formnlAtisn rtom~inP~l fluid and readily resuspended with time.
The following P.~mrles X and Y illllctr~tP advantages of the invention in various S solvents even though they are carried out in the abse.lce of any pçstiCi~ gl~di~ nl.
~:7.~AMPLE X _7,'' ."
This P~mrle shows micro~nc~rsnl~tion of a high density organic solvent, chlolurol,l.~ with Agrimer~9 DA-10 as çmlllcifiPr 90.00 Grams of chloror~ co~ g 5.56 grams PAPI~ 2027 was Pmlllcifi~d into 60.21 grams water co~ g 4 grams Agrimer~ DA-10. An emulsion was formed at high shear with a Waring blender. To the ~mnlcion~ after 1 min. of shear was added 5.56 grams of 43.37% l.~ ell~ylf.~rAiA~in~. After an a(l~lition~l 15 min. of slow shear stirling the formnl~hon was bottled. Discreet, individual mi~;ruca~ules 1-5 microns in metpr were obsel~ed microsco~:caUy. The formnlAtion 1~ r(l fluid and readily 15 l~i,u~nded widl time.
FX~MPLE Y
This P~mrle shows mi~ir~f .~A~ tion of a low density organic solvent, tolll~ne, with Ag~ 9 DA-10 as Pmnlcifi~r 80.00 Grams of toluene cc...li.;..;..g 5.56 grams PAPI(~9 2027 was ~mnlcifi~d into . 20 60.21 grams water ccl~lA;~ p 4 grams Agrimer~) DA-10. An ~mlllsi~n was formed at high shear with a Waring blender. To the ~mnl.cion, after 1 min. of shear was added 5.56 grams of 43.37% 1~ .yll -~rcli~ in~. After an a~l-liti- nAl 15 min. of slow shear stirring the formnl~tiolt was bottled. Discreet, individual microca~ules 1-20 microns in mçt~ .r were observed mi~;rosco~ically. The formnl~tio~ "S~ ç~ fluid and readily resuspended with time.
~X AMPLE 9 This P.~mrle shows miclu.,-~c^~ tion of a fimgi~ ç snlntion in organic solvent, with Agrimer~9 DA-10 as P.~ r 80.00 Grams of fln~ 7ole in ~ylene ~50%) co. ~ g 5.56 grams PAPI@D 2027 was ~m~ ifi~rl into 60.21 grams water conl~ ng 4 grams Agrimer~ DA-10. An emulsion was formed at high shear with a Waring blend~r To the ~mlll~ioll~ after 1 min.
of shear was added 5.56 grams of 43.37% hlos~methylen~ min~. After an acl-lition~l 15 min. of slow shear stirring the fc-rm~ tion was bottled. Discreet, individualmi.;ruc~ ..les 1-10 microns in li ....ct~ . were observed miclûsc~;_aUy. The formlll~tion 35 rom~in~(l fluid and readily l~u~lded with time.
This Fs~mrle shows mi~u~ cAl~ tion of a liquid cineole herbicide, ; ....cllylin, with AgnmerQ DAQ-2000, as ~mnl.~ifi~r, producing a polyester shellwall.
wo 94~ul3g 2 1 S O 9 2 0 PCTIUS93/11523 80.00 Grams of cinmethylin CO~ 17.77 grams s~acoyl rhlori-ie was emulsi~led into 60.21 grams water co.~ .;ug 4 grams Agrimer~ DAQ-2000. An ~-mlll.cion was formed at high shear with a Waring blender. To the ~m~ ion, after 1 min.
of shear was added a solution co~ g 6.33 grams 1,6-h~ rrliol~ 1.71 grams 1,3,5-b~ ;ol, and 12.00 grams 50% aqueous NaOH. After an ~rlrlition~l lS min. ofslow shear stirring the form~ tion was bottled. Discreet, uldivi~ual microc~rsules and some irregular shaped micn~c;~ les 1-50 microns in ~ metP.r were observed mi ;lusco~ically. The form~ tilm r~-m~inP~l fluid and readily ~ le~l with time.
~MPLE 1 1 This F.~mrle shows mi;lo- ~r~ tion of aliquid cineole herbicide, ~inmetllylin, by in situ mi~ ca~ tion, with Agrimer~ DA-10 as Pm~ if i~r.
200 Grams of ~inmethylin c~ .;..g lS grams PAPI~) 2027, lS grams of toluçnP-liiso~;y~lale, and 0.1 grams of dilJulyllill rlil~llr~tP, catalyst, was emnl~ifie~ into 154 grams water co.-l*;~ g 6 grams AgrimerlM DA-10. An em~ ioll was formed at lS high shear with a Waring blender for S min. The ~ 't was raised to 50C, and slow shear co~ e~3 for 1 h. Discreet, individual micr~c~ lPs 1-7 microns in ~ mete.r were obs~v~d miclosc-,~;c~lly. The formnl~ti~ n rPm~inP~i fluid and readily lt;su~ended with time.
ThisF~mrleshows llli~;lU -~rs~ tionofaliquidcineoleherbicide, ~-inm~thylin, with Agrimer~ DA-10 as PmlllcifiPr, ~lodu~lg a mixed ~olyul~afpolyamide shell wall.
80.00 Grams of f ;-----ell.yLl c~...li~;..;.~g 2.8 grams PAPI~) 2027, 1.4 grams s~bacoyl rhlr~ri~le, and 1.2 grams ll~uesoyl ChlQritlÇ, was ~mlllcifiç~ into 60.21 grams 25 water c~ ;..;.-g 4 grams A~i,~ ~ DA-10. An Pmlllcion was formed at high shear with aWaring blender. To the Pmlllcinn, after 1 min. of shear was added a solution c-,..l~;..;..g 7 grams of 43.37% hP~methyle.~ inP, and 2.5 grams 50% aqueous NaOH. After an ~d~lition~l 15 min. of slow shear stirring the fonn~ tion was bottled. Discreet, individual micloca~ules 1-10 microns in ~ -" t~ were obs~ d micloscu~ically. The forrnul~tion 30 rPm~inPcl fluid and readily l~i~U~. ..ded with time.
Claims (6)
1. A process for preparing a highly concentrated composition of particles of encapsulated active pesticide(s) in water of concentrations of 480 to 700 grams of pesticide per liter of composition wherein the pesticide is encapsulated in a plastic shell with substantially no agglomeration of the particles, said process comprising (a) mixing a water immiscible monomer A and an active pesticidal ingredient in the form of a liquid, melted solid or solution of said active ingredient in an unreactive water-immiscible solvent, said monomer selected from the group consisting of diacid and polyacid chlorides, dichloroformates, polychloroformates, disulfonyl and polysulfonyl chlorides, diisocyanates, polyisocyanate and mixtures thereof, to form a solution of the monomer in the active ingredient to be encapsulated;
(b) dispersing in water containing 0.5 to 15% by weight of an emulsifier the solution of the monomer and active pestici(le ingredient, said emulsifier being a water-soluble co- or ter-polymer of vinylpyrrolidone, excluding co-polymers withalkylated vinylpyrrolidone, to form an oil-in-water emulsion with said droplets in the size range of 1 to 100 microns;
(c) adding to the emulsion of (b) a water-soluble monomer B which will react with monomer A by interfacial polycondensation to form a shell around the pesticidal ingredient, said water-soluble monomer B selected from the group consisting of diaminess or polyamines, diols or polyols; or alternatively when monomer A is a diisocyanate, a polyisocyanate or mixtures thereof, optionally including a catalyst in the solution from (a), the concentration of monomer A being from 3.5% to 21% by weight and the concentration of monomer B being 1.5% to 9% by weight both based on the weight of active ingredient and heating the emulsion of (b) to hydrolyze monomer A to amine groups whereby the amine groups generated by hydrolysis react with residual isocyanate monomers to generate a shell wall of polyurea;
(d) optionally, adding formulation adjuvant(s); and (e) optionally, drying followed by granulation of the solid residue to form a flowable solid composition.
(b) dispersing in water containing 0.5 to 15% by weight of an emulsifier the solution of the monomer and active pestici(le ingredient, said emulsifier being a water-soluble co- or ter-polymer of vinylpyrrolidone, excluding co-polymers withalkylated vinylpyrrolidone, to form an oil-in-water emulsion with said droplets in the size range of 1 to 100 microns;
(c) adding to the emulsion of (b) a water-soluble monomer B which will react with monomer A by interfacial polycondensation to form a shell around the pesticidal ingredient, said water-soluble monomer B selected from the group consisting of diaminess or polyamines, diols or polyols; or alternatively when monomer A is a diisocyanate, a polyisocyanate or mixtures thereof, optionally including a catalyst in the solution from (a), the concentration of monomer A being from 3.5% to 21% by weight and the concentration of monomer B being 1.5% to 9% by weight both based on the weight of active ingredient and heating the emulsion of (b) to hydrolyze monomer A to amine groups whereby the amine groups generated by hydrolysis react with residual isocyanate monomers to generate a shell wall of polyurea;
(d) optionally, adding formulation adjuvant(s); and (e) optionally, drying followed by granulation of the solid residue to form a flowable solid composition.
2. The process of Claim 1 wherein interfacial polycondensation is to be achieved using monomer B.
3. The process of Claim 1 wherein monomer A is a diisocyanate, a polyisocyanate or mixtures thereof and monomer A is hydrolyzed in the presence of a catalyst and heated to form an amine that will react with residual isocyanate monomers.
4. The process of Claim 2 wherein and the concentration of emulsifier is from about 2% to about 6% by weight, based on the weight of active ingredient to be encapsulated.
5. A composition comprising highly concentrated microcapsuled active pesticidal particles of 1 to 100 microns in diameter suspended in an aqueous liquid, said microcapsuled pesticides comprising a liquid, solid or solution of an active pesticide in an unreactive water-immiscible solvent within an encapsulating wall of polymeric material wherein:
(a) said active pesticide being present at a concentration ranging from about 480 to about 700 grams per liter of composition;
(b) said encapsulating wall of polymeric material is the reaction product of a first shell wall component which is a difunctional or polyfunctional reactant soluble in the active pesticide, and a second shell wall component which is water-soluble and which is a difunctional or polyfunctional reactant and wherein the concentrations of said first and second shell wall components are from about 3.5% to about 21.0% and from about 1.5%
to about 9.0%, respectively, by weight relative to the weight of the active ingredient to be encapsulated; and (c) said aqueous liquid is water containing (i) from about 0.5% to about 15% by weight of an emulsifier relative to the weight of said active pesticide to be encapsulated, said emulsifier being a water-soluble co- or ter-polymer of vinylpyrrolidone, excluding co-polymers with alkylated vinylpyrrolidone and (ii) optionally, from about 0.01% to about 30% of a formulation adjuvant based on the total weight of the composition.
(a) said active pesticide being present at a concentration ranging from about 480 to about 700 grams per liter of composition;
(b) said encapsulating wall of polymeric material is the reaction product of a first shell wall component which is a difunctional or polyfunctional reactant soluble in the active pesticide, and a second shell wall component which is water-soluble and which is a difunctional or polyfunctional reactant and wherein the concentrations of said first and second shell wall components are from about 3.5% to about 21.0% and from about 1.5%
to about 9.0%, respectively, by weight relative to the weight of the active ingredient to be encapsulated; and (c) said aqueous liquid is water containing (i) from about 0.5% to about 15% by weight of an emulsifier relative to the weight of said active pesticide to be encapsulated, said emulsifier being a water-soluble co- or ter-polymer of vinylpyrrolidone, excluding co-polymers with alkylated vinylpyrrolidone and (ii) optionally, from about 0.01% to about 30% of a formulation adjuvant based on the total weight of the composition.
6. The composition of Claim 5 wherein the concentration of the active pesticide is 480 grams to 600 grams per liter of aqueous solution.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US98790392A | 1992-12-04 | 1992-12-04 | |
| US07/987,903 | 1992-12-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2150920A1 true CA2150920A1 (en) | 1994-06-23 |
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ID=25533679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2150920 Abandoned CA2150920A1 (en) | 1992-12-04 | 1993-12-02 | Microcapsule formulations of agricultural chemicals |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0671878A1 (en) |
| JP (1) | JPH08504206A (en) |
| AU (1) | AU672465B2 (en) |
| CA (1) | CA2150920A1 (en) |
| WO (1) | WO1994013139A1 (en) |
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| GB9615158D0 (en) * | 1996-07-19 | 1996-09-04 | Dowelanco | Process for preparing storage-stable pesticide dispersion |
| US6022501A (en) * | 1996-08-15 | 2000-02-08 | American Cyanamid Company | pH-sensitive microcapsules |
| TW561064B (en) * | 1998-03-05 | 2003-11-11 | Sumitomo Chemical Co | Method for microencapsulating of a solid substance |
| FR2806005B1 (en) * | 2000-03-10 | 2002-06-14 | Univ Claude Bernard Lyon | PROCESS FOR THE PREPARATION OF COLLOIDAL PARTICLES IN THE FORM OF NANOCAPSULES |
| US20060165746A1 (en) | 2005-01-24 | 2006-07-27 | Arie Markus | Formulations containing microencapsulated essential oils |
| US8753676B2 (en) | 2006-02-15 | 2014-06-17 | Botanocap Ltd. | Applications of microencapsulated essential oils |
| CN103889217A (en) * | 2011-08-25 | 2014-06-25 | 陶氏益农公司 | Pesticidal compositions with enhanced active ingredient retention in pest control zones |
| BR102012027933A2 (en) * | 2011-11-01 | 2015-11-17 | Dow Agrosciences Llc | stable pesticide compositions |
| RU2628579C2 (en) | 2012-07-27 | 2017-08-21 | Фмк Корпорейшн | Compositions of clomazone |
| EP3170552A1 (en) * | 2015-11-23 | 2017-05-24 | Basf Se | Microcapsule comprising a polymeric shell and a hydrophilic or hydrophobic core material |
| US20190350197A1 (en) | 2016-12-07 | 2019-11-21 | BASF Agro B.V. | Composition comprising polyurethane microcapsules comprising cinmethylin |
| CN110049675A (en) | 2016-12-07 | 2019-07-23 | 巴斯夫农业公司 | By tetramethylxylylene diisocyanate and the polyamine at least three amine groups preparation shell cinmethylin microcapsules |
| MY193136A (en) * | 2017-01-10 | 2022-09-26 | Basf Agro Bv | Composition comprising cinmethylin-containing microparticles and a further herbicide |
| WO2018130589A1 (en) | 2017-01-10 | 2018-07-19 | BASF Agro B.V. | Microcapsules comprising cinmethylin in the core and a polyurea derived from diphenylmethane diisocyanate or an oligomer thereof |
| US11952492B2 (en) | 2020-11-20 | 2024-04-09 | Encapsys, Llc | Biodegradable, controlled release microcapsules |
| EP4247537A1 (en) * | 2020-11-20 | 2023-09-27 | Encapsys, LLC | Biodegradable, controlled release microcapsules |
| WO2024038046A1 (en) | 2022-08-18 | 2024-02-22 | Basf Se | Process for producing microparticles |
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| US3691125A (en) * | 1970-05-04 | 1972-09-12 | Gaf Corp | Stable aqueous emulsions |
| DE2237503A1 (en) * | 1972-07-31 | 1974-10-03 | Basf Ag | METHOD OF MANUFACTURING MICROCAPSULES |
| US5160529A (en) * | 1980-10-30 | 1992-11-03 | Imperial Chemical Industries Plc | Microcapsules and microencapsulation process |
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| CA1211892A (en) * | 1982-09-20 | 1986-09-23 | James R. Cho | Preparation of polyvinylpyrrolidone or vinylpyrrolidone/vinyl acetate copolymers of various molecular weights using a single initiator system |
| US4554311A (en) * | 1982-09-20 | 1985-11-19 | Gaf Corporation | Method of preparing an aqueous solution comprising vinylpyrrolidone/vinyl acetate copolymers of various molecular weights using a single initiator system consisting essentially of t-Butylperoxypivalate |
| US4554312A (en) * | 1982-09-20 | 1985-11-19 | Gaf Corporation | Method of preparing aqueous solutions of polyvinyl-pyrrolidone homopolymer of various molecular weights using a single initiator system consisting essentially of t-Butylperoxypivalate |
| US4520179A (en) * | 1982-09-20 | 1985-05-28 | Gaf Corporation | Preparation of vinylpyrrolidone/vinyl acetate copolymers of various molecular weights using a single initiator system consisting essentially of t-Butylperoxypivalate |
| US4640709A (en) * | 1984-06-12 | 1987-02-03 | Monsanto Company | High concentration encapsulation by interfacial polycondensation |
| JPH0474522A (en) * | 1990-07-16 | 1992-03-09 | Tosoh Corp | Method for preventing solidification of powder |
| DE4209632A1 (en) * | 1992-03-25 | 1993-09-30 | Basf Ag | Polymers containing sulfo groups |
-
1993
- 1993-12-02 CA CA 2150920 patent/CA2150920A1/en not_active Abandoned
- 1993-12-02 JP JP6514213A patent/JPH08504206A/en active Pending
- 1993-12-02 EP EP94902441A patent/EP0671878A1/en not_active Withdrawn
- 1993-12-02 AU AU56813/94A patent/AU672465B2/en not_active Withdrawn - After Issue
- 1993-12-02 WO PCT/US1993/011523 patent/WO1994013139A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08504206A (en) | 1996-05-07 |
| EP0671878A1 (en) | 1995-09-20 |
| WO1994013139A1 (en) | 1994-06-23 |
| AU672465B2 (en) | 1996-10-03 |
| AU5681394A (en) | 1994-07-04 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Dead |