CN1173145A - Microencapsulation process and product - Google Patents
Microencapsulation process and product Download PDFInfo
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- CN1173145A CN1173145A CN95197380A CN95197380A CN1173145A CN 1173145 A CN1173145 A CN 1173145A CN 95197380 A CN95197380 A CN 95197380A CN 95197380 A CN95197380 A CN 95197380A CN 1173145 A CN1173145 A CN 1173145A
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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
- B01J13/16—Interfacial polymerisation
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- 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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- 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
- B01J13/04—Making microcapsules or microballoons by physical processes, e.g. drying, spraying
- B01J13/043—Drying and spraying
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Abstract
The present invention relates to the microencapsulation of various materials, in particular pesticidal materials, to produce both wet and dry formulations. In particular, the invention relates to encapsulating such materials by incorporating a PVA into an interfacial polycondensation system for producing microcapsules, and subsequently spray drying the resulting microcapsules in the presence of the PVA, and optionally a further quantity of PVA which may be the same or different from the one adopted in the microencapsulation step, so that the encapsulated product can be diluted in water, in order to produce aqueous pesticidal compositions, which can be applied by conventional spray techniques.
Description
The present invention relates to the microencapsulation of various materials, particularly agricultural chemicals, to produce dried, wet preparation.Particularly, the present invention relates to the microencapsulation of these materials, so that the encapsulated products dilutable water, thereby obtaining moisture composition pesticide, the spray technique of its available routine is used.
The encapsulated of agricultural chemicals, plant growth regulator or the like is attractive day by day in recent years field.For safety, and be convenient to distribute, supplying these materials with the aqueous dispersions form of drying solid is especially easily, and easy dilute with water disperseed when this aqueous dispersions was used in the field.
In recent years, the microencapsulation for various agricultural chemicals has proposed different suggestions.For example, the technology (as trefanocide) that US-A-5160530 (Griffin company) discloses a kind of pesticide capsuleization is earlier with the active ingredient fusion, then with film forming polymer for example polyvinyl alcohol (PVA) mix.The emulsified together and spray-drying of these materials then.
US-A-4244836 (Hoechst company) discloses a kind of similar pesticide capsule method, the i.e. dispersion liquid of spray-drying active ingredient and polyvinyl alcohol.
Though for some system, the technology that these documents disclosed is useful, but they also have many shortcomings, for example, active ingredient can be diffused in the product, cause active ingredient crystallization in polyvinyl alcohol matrix, the active ingredient of (particularly in the Griffin method) fusion when being chilled to room temperature may produce undesirable polycrystalline form again.
US-A-4936901 (Monsanto company) discloses encapsulated another method, and at this, the microcapsules that contain effective composition are that the reaction by interfacial polycondensation reaction-isocyanates and polyamine makes.Then, the microcapsules with the interfacial polymerization of gained carry out spray-drying.Document explanation, polyvinyl alcohol can be used as the suspension aids of spray-drying stage, and, the microcapsules that this method is produced can not be controlled rate of release.And some active ingredient can be diffused into outside the microcapsules of interfacial polymerization thereby produce crystallization (active ingredient is under the situation of solid under the environment temperature) in storage process.Another problem of this method is that the rate of release of all products is all slow, because their size distribution are big, and the cyst wall of polymer is thick.
A specific question of not referring to fully in this piece document is to produce to quicken to discharge active ingredient, rather than is detained or incurs loss through delay the microcapsules that discharge active ingredient.Usually require the control release dosage form can produce a kind of biological agent rapidly (" knocking down "), and then continue to discharge active ingredient (" residual effect ").The general capsule that requires to discharge rapidly is granule (typical particulate volume diameter (VMD) is less than 5 microns), or has extremely thin polymer wall.Prepared product does not reach and knocks down desired so little particle rapidly in US-A-4936901.Providing granular size in the literature is that size distribution is 1～50 micron a particle (not being the particulate volume diameter).This surfactant of being talked about in the document is to be not suitable for forming this volume diameter less than 5 microns microcapsules.
Do not associate EP-A-0611253, US-A-5332584 and US-A-5324584 example as can be known, polyvinyl alcohol can be used as surfactant or colloid protective agent in the pesticide capsule metallization processes.These documents do not propose polyvinyl alcohol and can be used as the active part that shell wall forms, and it can influence and effectively control the release characteristics of the microcapsules that produced.
We have found that, polyvinyl alcohol is introduced the interfacial polycondensation system of producing microcapsules, in the presence of polyvinyl alcohol, formed microcapsules are carried out spray-drying then, with can randomly add polyvinyl alcohol again, its amount can be identical with the microencapsulation step, also can be different, and the microcapsules that obtain have thus improved bin stability, particularly the particle at microcapsules very little (for example less than 5 microns time) has improved the leaching of active ingredient from the gained microcapsules.
Therefore, first embodiment of the present invention has provided the method for preparing encapsulated material, this method comprises the microcapsules that contain this material by interfacial polycondensation reaction formation, and the microcapsules that spray-drying obtains in the presence of polyvinyl alcohol (PVA), wherein, polyvinyl alcohol is present in the process of the interfacial polycondensation reaction that forms microcapsules.
As noted above, polyvinyl alcohol can further be added in the mixture that contains microcapsules before spray-drying, and its amount is preferably different with the used amount of interfacial polycondensation step.
At the polyvinyl alcohol that the microencapsulation step is used, its degree of polymerization can from 50 to 5000, and its degree of hydrolysis can from 70% to 100%.Requirement to the polyvinyl alcohol characteristic: before polycondensation phase, it should be an effective emulsifying agent, and when forming capsule, it can keep the stability of capsule, and after spray-drying, can keep the moist again of capsule in the time of final the use.The polyvinyl alcohol of a grade can not satisfy these requirements fully.Now found a kind of reasonable compromise material, its degree of polymerization is about 300, degree of hydrolysis about 88%.
Additional polyvinyl alcohol available before spray-drying is mainly selected according to following condition: the solubility to encapsulated material is little, and is moistening more easily in cold water (may be hard water).The polyvinyl alcohol of chemical modification, polyvinyl alcohol for example sulfonation or carboxylation is specially adapted to this purpose.
The interfacial polycondensation effect that forms microcapsules can be carried out according to any method as well known to those skilled in the art.
In preferred embodiments, the reaction of the interfacial polycondensation in the presence of polyvinyl alcohol is by carrying out between PIC and the polyamine.Owing in the polycondensation process that forms microcapsule wall, there is polyvinyl alcohol to exist, the character of its surfactant had both guaranteed high concentration, guaranteed preferred orientation again in oil/water termination, the polyvinyl alcohol that side O-OH base is arranged, can mix polyurethanyl group with isocyanate reaction, thereby enter the microcapsules cyst wall of polymer.The penetrability of polyether polyols with reduced unsaturation is different fully with polyureas, and the latter is made by PIC and polyamine reaction.Utilizable other interfacial polycondensation reaction also has isocyanates/polyalcohol, isocyanates/water, and the reaction of isocyanates/acid chloride.
Can for example be had by encapsulated agricultural chemicals:
The amitraz cynock
The triazotion cyfloxylate
The azinphos-methyl cypermethrin
The Citrazon bromophos
The bifenthrin fenisobromolate
Binapacryl fourth fork prestige
Bioresmethrin oxygen fourth fork prestige
The dursban insecticidal amidine
The chlorpyrifos-methyl chlorobenzilate
The Acaralate phosfolan
The chlorophoxim phosmet
The Nemacur Carbamult
The Osbac quinalphos
The r-666 Chryson
The methidathion Swebate
The decis tetramethrin
Dicofol fluorine ester chrysanthemum ester
The salithion Pynamin
The Elacron Benfuracard micro
The 5a,6,9,9a-hexahydro-6,9-methano-2,4 Dtrans allethrin
EPN/benzene worm prestige S-Dtrans allethrin
The dinobuton bioresmethrin
The tetradiphon Buprofezin
The tralomethrin chlorfenviphos
N-2,3-dihydro-3-methyl isophthalic acid, 3-UC 62644
Thiazoline-2-base-2, the 4-chlormephos
The xylidine cycloprothrin
Parathion-methyl is protected
The zolone time
The lambda-cyhalothrin flufenoxuron
Nail body cypermethrin taufluvalinate
Second body cypermethrin peace fruit
The demeton-methyl Entocon ZR 512
DDVP propylamine phosphorus
The disulfoton Mobucin
The Hinosan karphos
The Prallethrin malathion
The esfenvalerate Cytrolane
The ethoprop Entocon ZR 515
Ether chrysanthemum ester methoxychlor
Oxygen Diothyl Menite
The fenazaquin Permethrin
The Folithion phenothrin
The fenthiocarb phenthoate dimephenthoate cidial
The Fenpropathrin pirimiphos ethyl
The Entex Actellic
The fenvalerate Profenofos
The flucythrinate Kayaphos
The propargite pyraclofos
Propetamphos/pyraclofos
Tefluthrin
Terbufos
Ravap
Tralomethrin
Bactericide
The M 9834 methyl stands withered spirit
The phonetic bacterium spirit of sulphur triazolone
The carboxin triadimenol
Dodemorfe penta ring azoles
The dodine oxole bacterium
The fenarimol butadiene morpholine
The Plondrel Bitertanol
Nitrile bacterium azoles cyproconazole
Nuarimol fluorine ether azoles
Oxidation Wei Xiu Ling Difenoconazole
The penconazole dimethomorph
Prochloraz alkene azoles alcohol
The long quinoline propiconazole of azoles
The kobam pyrifenox
The fenpropidin Tebuconazole
The fluchloralin tridemorph
Flusilazole fluorine bacterium azoles
The acid amides azoles
Herbicide
2,4-drips (ester) cremart
2,4-Embutox (ester) Amex820
The Acetochlor butylate
The alachlor carbetamide
The anilofos Mo 9 granular
The benfluralin chlorpropham
The benfuresate cinmethylin
The bensulide clethodim
The suffer clomazone
The bifenox morpholine acid dichloride picoline
Brominal (ester) Vi par (ester)
The Brominal cycloate
The butachlor cycloxydim
Different phenmedipham pyrrole fluorine chlorine standing grain spirit (methyl esters)
2,4-drips propionic ester ioxynil (ester)
Chloroformate grass/peace tower isopropaline,2,6-dinitroN,N-dipropylcumidine
Dinitramine Vi par (ester)
Fourth fluchloralin isopropyl methoxalamine
The ethofumesate monalide
The Osbac proproanmide
Oxazole diclofop-methyl nitrofen
The fluazifop Lonster
Pyrrole fluorine dogstail-P Oxyfluorfen
The fluchloraline pendimethalin
Flufenoxim enemy gram grass
The benfluralin phenmedipham
Fluorodifen picloram (ester)
The fluoroglycofen-ethyl third careless amine
Fluorine chloramines pyridine profluralin
The Florencol propachlor
Fluorochloridone/pyrrole fluorine chlorine standing grain spirit Stam F-34
The ethoxyethyl propaquizafop
Reach grass and end tridiphane
The quizalofop-ethyl trefanocide
Triclopyr
Other agricultural chemicals, for example the nitrification inhibitor N-Serve also can use this method.Composition of the present invention also comprises the mixture of two kinds or more kinds of agricultural chemicals, and in some embodiments, they can form a kind of eutectic mixture that fusing point is lower than each component fusing point that has.
This agricultural chemicals can be a kind of derivative that dissolves in organic solvent of agricultural chemical compound, and this agricultural chemicals is low solubility in organic solvent originally, or insoluble.
Content of effective can be 30-90% (weight) 60-85% preferably for example, and more preferably 75-80% is a base with the spray-drying formulation.
As implied above, method of the present invention is for producing short grained microcapsule formulations, and for example VMD is equal to or less than 5 microns, and the microcapsule formulations that particularly is equal to or less than 2 microns is very favourable.The major advantage of these Caplets is that they provide bigger quality and surface area ratio than bulky grain, therefore can improve rate of release, have the stronger power of knocking down.And these granules are also good than bulky grain in the permeability on soil or weeds surface, therefore, when using, have better effect on the soil of needs migrations or weeds.This short grained another benefit is when VMD dwindles, may continue to increase the amount of the cold active matter of mistake that exists with liquid form.This just might be with reliable method, and without the capsule of solvent production liquid core, this is favourable to environment, and in final products, content of effective is than higher.
Exist the liquid core that following benefit is arranged in the capsule of being made by cold excessively fusion active ingredient, from viewpoint of the present invention, the most important thing is one, liquid core release active ingredient is faster than solid.The short grained active ingredient rate of release that this mixing is formed obviously improves.Its two, therefore its core is not crystallization, can not cause capsules break, causes discharging too early or makes process preparation in instability storage period.Its three, the composition of remaining valid is in liquid condition, can not produce that the lower polycrystalline form of biologically active-this is a problem that proposes in US-A-5160530 (Griffrin) method.
Obviously, when active ingredient can be dissolved in solvent, just these problems can not run into.When using solvent if desired, any non-water-soluble solvent all can adopt.Typical examples of solvents has aromatic solvent, alkyl substituted benzene particularly, for example dimethylbenzene or propylbenzene cut, and the naphthalene and the Fluhyzon cut that mix, mineral oil, kerosene, the diformamide of the dialkyl amide of aliphatic acid, particularly aliphatic acid, as sad dimethylformamide, chlorinated aliphatic hydrocarbon and aromatic hydrocarbon are as 1,1, the 1-trichloroethanes, chlorobenzene, the ester of ethylene glycol derivative is as the acetate of the methyl ether of the acetate of normal-butyl, ethyl or the methyl ether of diethylidene ethylene glycol, dipropylene ethylene glycol; Ketone, isophorone for example, trimethylcyclohexanone (dihydro-isophorone) and acetate product are as capryl acetate or acetic acid heptyl ester.Preferred organic is dimethylbenzene, propylbenzene cut, acetic acid Arrcostab and Fluhyzon cut.
A benefit that has this encystation method of polyvinyl alcohol in becoming the capsule course of reaction is by the time before the change adding polyamine, the amount that can be controlled at polyurethane and polyureas in the cyst wall more accurately is because these two kinds of polymer are completely different for the diffusivity that becomes capsule material, so except control wall thickness and capsule size, polyurethane and the ratio of polyureas have become to control one of the active ingredient rate of release independently method again.
In another embodiment, solvent can be polymerisable monomer, unsaturated vinyl monomer (as styrene, AMS, (methyl) ethyl-methyl acrylate, ethylene halide or acrylonitrile) for example, these monomer polymerizations produce the substrate core of a capsule then, can further control the rate of release of active ingredient.
The another advantage that has the encapsulated method of polyvinyl alcohol in encapsulated reaction is because the diversity of band side group-OH group, form in the course of reaction at cyst wall, polyvinyl alcohol can be from chemically connecting with cyst wall, these connections can produce the polyvinyl alcohol (" tail ") that some ends are, some are the dual polyvinyl alcohol that is (" taking ring "), and some are the multiple polyvinyl alcohol that is (" long string things ").At spray-drying stage subsequently, having is not that the polyvinyl alcohol that connects exists as yet, can produce a kind of dryed product, and this is a shortcoming.In spray-drying, concentration (polyvinyl alcohol, capsule and any solute that adds are as the concentration of salt) increases very fast.Purpose is to produce the layer of even water-soluble polymer around each capsule, forms film when drying.Obviously, in dry run, with increasing of concentration, flocculation may appear.Therefore capsule may contact with capsule, is directed at irreversible cohesion." take ring " and the existence of " long string thing " is to prevent rewetting profit difference and the unsettled basic measures of colloid.They also have a more significant advantage, allow more electrolysis degree to be added in the capsule suspension liquid, and these electric charges can help the product that is dried moistening more rapidly, as at EP-A2-0568379 (Rohm; That is told about Haas) is the same.The electrolyte of any high concentration is added in the conventional capsule suspension thing, generally all can cause the irreversible cohesion of capsule.
The another advantage of encapsulated method of the present invention is, can produce the dry composition that contains 2 kinds or more active ingredients, if and directly processing of these active ingredients (promptly that one or the two is in addition not encapsulated), the product of gained is being unsettled chemically or physically.On the one hand, said active ingredient can be encapsulated respectively, alternative, in the embodiment preferred, one or more active ingredients (or some part of single active ingredient) can be encapsulated with method of the present invention, and remainder does not then have encapsulated.Like this, not encapsulated active ingredient is available immediately from biology when using, and encapsulated material discharge will be slowly many.The amount of the various active ingredients of using by different way depends on specific method of application fully, but various in general content of effective can from 0.1 to 99.9% (weight), being that radix calculates by the total amount of encapsulated material.
Microcapsules of the present invention can prepare by solution or fused mass, polyvinyl alcohol (as the aqueous solution) and a kind of material (as isocyanates) that can produce interfacial polycondensation that high shear mixing contains effective composition (as agricultural chemicals).Polyvinyl alcohol in some systems, does not need to add emulsifying agent as a kind of emulsifying agent again.But,, also need to add in addition the emulsifying agent of known type in order to produce desirable short grained emulsion.When the size of emulsion reaches requirement, add other polymeric cross-linker (as polyamine) to finish interfacial polycondensation.
As mentioned above, the reasonable reactant of polycondensation is a polyamine, its normally a kind of water-soluble reaction polyamine, and for example diethylenetriamines or tetren, these amine one add, and just begin to react with isocyanates on the interface.Sometimes, control more completely can be by being dissolved in the water-soluble amine salt of aqueous phase in the employing of the commitment (for example before the emulsification) of this technology or the oil-soluble amine salt in oil phase is realized.Because they all are salts, can be not immediately and isocyanate reaction, but adjust to when discharging unhindered amina as pH, as long as the crosslinking agent existence is arranged, they will react rapidly.
The system of each component can be carried out high shear mixing in batches, or online mixing continuously, under the previous case, the time of adding or release reaction amine is by (this obviously is relevant with every batch size) that formation time determined that require to form the emulsion that has accurate particle size distribution, under then a kind of situation, interfacial reaction can be controlled better, because by selecting the decanting point in the process-stream simply, just can add or release amine, thereby can control the ratio of urea/carbamate basically fully in any required time.
As mentioned above, all polyvinyl alcohol of Cai Yonging in order to form microcapsules, can add at the very start in the methods of the invention,, preferably after microcapsules form, add extra polyvinyl alcohol before the spray-drying again.The polyvinyl alcohol amount that adds in second stage generally was at least 0.5: 1 with the ratio of initial addition.
Also can add other conventional auxiliary agent in the prescription, as emulsifying agent, dispersant, disintegration auxiliary agent, salt and film forming polymer.
Many embodiment preferred of the present invention are described in following example, and some characteristic of these examples is listed in the accompanying drawing and is illustrated.
Fig. 1 represents the dependence of crystallinity and VMD
Fig. 2 represents crystallinity and residual influence
Example 1
By high shear mixing 20% (w/w) polyvinyl alcohol water solution (GLO3, NipponGohsei, degree of hydrolysis 88%, the degree of polymerization about 300), and remain in 55 ℃ the water-bath with the preparation emulsion.By quantity shown below, chlopyrifos and the PIC (VoranateM220) of fusion mixed, then under the high shear stirring, this mixture is added in the polyvinyl alcohol in the water-bath.
Former medicine 93.9 grams of chlopyrifos
Voranate M200 4.7 grams
GLO
312 grams, 15%w/w solution
Diethylenetriamines 1.25 grams are dissolved in the 65 gram water.
In about 100 gram samples, VMD is dropped to below 1 micron, incorporation time got final product in 30 seconds, if sample many (500 gram) needs 90 seconds.
VMD reach the institute set the goal after, under high shear, add diethylenetriamines.
Isocyanates and polyamine, polyvinyl alcohol reaction produce the microcapsules that contain the active ingredient that is scattered in water.
In order to obtain dryed product, with the wet capsule and the GLO of 0.855kg 21% aqueous solution
3Mix, and adjust the viscosity of suspension, make it to reach the suitable spray-dired level (approximately 100mPas) of carrying out with deionized water.Microcapsule suspensions is approximately contained the dryed product of 75%w/w chlopyrifos by spray-drying.After the PVA that adds be that the ratio that makes polyvinyl alcohol in dryed product is provided like this is that initial PVA accounts for 66, the PVA that then adds accounts for 33%.When carrying out spray-drying inlet temperature 120-150 ℃ and outlet temperature 65-85 ℃.Product is the near-white free flowing powder, water content about 0.5%.Wet capsule product and dryed product when putting into water and make it to disperse, all about 1 micron of its granular size (VMD).
The rate of release test
The rate of release test of product: the dilution that will contain 1000ppm (weight) active ingredient is sprayed onto on the sheet glass, at 20 ℃, stores in the environment of circulation of air after 24 hours, measures the amount of the active ingredient that stays.The product of example 1 provides the residue that is retained in 95% on the sheet glass.
Example 2
By the wet capsule of method preparation of similar example 1, but the continuous processing of employing " online " blender, it is as follows to fill a prescription:
Former medicine 93.9 grams of chlopyrifos
Voranate M200 2.94 grams
GLO
316.8 gram, 21% aqueous solution
Diethylenetriamines 1.56 grams are dissolved in the 65 gram water.
This wet capsule (5kg) is mixed with 200 gram 10% carboxylation polyvinyl alcohol (trade mark KM118) solution, press the preceding method spray-drying then, approximately contained the dryed product of 75%w/w chlopyrifos.To wet capsule product and dryed product put into water, after the dispersion, and about 0.6 micron of its granular size (VMD).The residual test of sheet glass shows, only residual 30% after storing in 24 hours, this shows that it is feature of the present invention that control discharges.
Example 1 is with the main distinction of example 2:
(i) isocyanates of example 1 is more, so wall thickness is greater than example 2.
(ii) the VMD of example 1 reduces so interfacial area is corresponding in proportion greater than example 2.
(iii), add 1 morning of time ratio example of amine in the example 2 because example 2 is to adopt on-line continuous technology, and example 1 is to adopt batch technology.
(iv) the particle diameter owing to example 1 is bigger, the VMD=1 micron, and crystallization has 10% to be solid form than example more than 2 approximately, and example 2, about 0.55 micron of VMD, crystal area proportion about 3%.
More than each factor all cause example 2 to have rate of release faster than example 1, store after 24 hours, residual active ingredient amount example 2 is than the example 1 much lower this point that just clearly illustrated that.Crystallization percentage and the good dependency relation that is retained in after 24 hours between the percentage of the active ingredient on the sheet glass are seen Fig. 2.
Example 3～6
Prepared more composition by the conventional method identical with example 1, each amount of substance of change is listed in table 1 (unit gram).Table 1 shows easy control release characteristics.
Table 1
| Example | ||||
| ????3 | ????4 | ????5 | ????6 | |
| Chlopyrifos | ?????42.29 | ?????42.29 | ????48.59 | ?????48.59 |
| Voranate | ?????7.09 | ?????7.09 | ????0.79 | ?????0.79 |
| GLO 3 | ?????2.00 | ?????12.00 | ????2.00 | ?????12.00 |
| Water | ?????38.00 | ?????28.00 | ????38.00 | ?????28.00 |
| Diethylenetriamines | ?????1.91 | ?????1.91 | ????0.21 | ?????0.21 |
| Water | ?????8.71 | ?????8.71 | ????10.41 | ?????10.41 |
| Granular size | ?????10.91 | ?????0.48 | ????9.05 | ?????0.96 |
| Residual % amount behind the rate of release-24 hour | ?????86 | ?????81 | ????64 | ?????5 |
All these wet capsule systems but with the GLO of q.s
3Mix, obtain 75% chlopyrifos product, do not carry out spray-drying at line technology according to above-mentioned.In the comparative study of the example 6 that adopts the direct replacing for polyvinyl alcohol of non-ionic surface active agent (ATLOX 4849B) of being with methyl end groups, granular size can reach 0.45 micron.But what do not succeed is to have formed a kind of wax shape deposit when this product carries out spray-drying in sprayer.All products of example 1-6 of the present invention all are high yield during spray-drying, and are all stable during storage.
Example 7-9
According to following formulation three products:
Former medicine 95.06 grams of chlopyrifos
Voranate M220 2.94 grams
GLO
37.54 gram
Water 30.16 grams
All products all are emulsified into emulsion at 50 ℃, add the diethylenetriamines of 1.90 grams in 77.7 gram water then.
In first example of these examples, add that the required time is different before the diethylenetriamines, so that change the ratio of polyureas and polyurethane in the cyst wall.This can be measured by far-infrared technique.The rate of release of these three different lot number products is measured by previous methods.
Table 2
| Example | Add the preceding time (branch) of DETA | Granular size (micron) | Urea: carbamate | Rate of release (residual %) |
| ????7 | Immediately | ?????0.62 | ?????2.94∶1 | ????85 |
| ????8 | ????1 | ?????0.68 | ?????2.36 | ????70 |
| ????9 | ????6 | ?????0.74 | ?????1.69 | ????55 |
Use this technology, the ratio that changes urea and carbamate is a useful instrument of the release characteristics of control product.Prepared a series of products with similar approach, so only the ratio that changes urea and carbamate by above-mentioned technology just make residual percentage behind the rate of release-24 hour from 100% to being lower than 10%.
Example 10
Chlorpyrifos-methyl is dissolved in aromatic solvent (Solvesso 200), adopts above-mentioned technology encapsulated then, the prescription of employing is as follows:
Chlorpyrifos-methyl 42 grams (former medicine)
Solvesso 200 20 grams
Diethylenetriamines 0.3 gram is dissolved in the 9.7 gram water
The granular size (VMD) of wet capsule is 1.72 microns, this product and enough poly-vinyl alcohol solution (GLO
3) mix, approximately contained the dryed product of 50%w/w as stated above after the spray-drying, promptly contain the free flowable powder of 50%w/w chlorpyrifos-methyl, be microcapsule product.This product stable upon storage adds and discharges Caplet behind the water rapidly, and product is added in the water, will produce VMD and be 1.66 microns granule, has shown that this product is dispersed into the stability that wet capsule size is distributed when adding water.
Example 11
Prepared and contained chlopyrifos, had a series of products of variable grain size distribution, and stored at ambient temperature.The about 40-42 of chlopyrifos fusing point ℃.At ambient temperature, these encapsulated products after a while can crystallization.The crystallization that occurs, available differential scanning formula calorimeter (DSC) is measured, and the fusing point heat absorption can be used to refer to and how many products are shown are in crystalline state.Adopt this technology to be surprised to find, compare with the product for preparing according to US-A-5160530 (Griffin) method, in system of the present invention, the chlopyrifos crystallization seldom, in the Griffin method, chlopyrifos is emulsification in poly-vinyl alcohol solution, and spray-drying obtains dryed product then.Fig. 1 has represented the crystallinity surveyed and the dependence of particle VMD, many compositions that will make according to the present invention are compared with the product that respective instance according to US-A-5 160530 (Griffin example) makes, can see, Griffin example degree of crystallinity about 30%, the VMD0.4 micron, and according to the onesize particle of capsule of the present invention preparation, expection degree of crystallinity about 3%.Obviously thisly encapsulatedly caused accurate liquid condition wonderful stable.Crystallinity (and granular size) indirectly is described in Fig. 2 to the influence of residual.Can see that product crystallization of the present invention is seldom (VMD is that 2.2 microns capsule is up to 15%), but the product of Griffin method is approximately 30% (in this method in the emulsion VMD about 0.4 micron).
Claims (19)
1. method for preparing encapsulated material, this method comprises the microcapsules that contain this material by interfacial polycondensation reaction formation, carry out spray-drying with the microcapsules with gained in the presence of polyvinyl alcohol, it is characterized in that, polyvinyl alcohol is present in the interfacial polycondensation course of reaction that forms microcapsules.
2. the method for claim 1, wherein the polyvinyl alcohol that further adds is to be added in the mixture that contains said microcapsules before said spray-drying step.
3. method as claimed in claim 2, the wherein said polyvinyl alcohol that before the spray-drying step, further adds be with the interfacial polycondensation process in used different polyvinyl alcohol.
4. the method for each claim as the aforementioned, the polyvinyl alcohol that adds for the first time wherein, degree of hydrolysis is 70～100%, the degree of polymerization is at least 50.
5. method as claimed in claim 4, the polyvinyl alcohol that adds for the first time wherein, degree of hydrolysis are about 88%, and the degree of polymerization is about 300.
6. the described method of aforesaid each claim, wherein the polyvinyl alcohol that adds for the second time is the polyvinyl alcohol of carboxylation or sulfonation.
7. the described method of aforesaid each claim, wherein, microcapsules form by PIC and polyamine reaction.
8. the described method of aforesaid each claim wherein is the 30-95% of the microcapsules weight after the spray-drying by encapsulated amount of substance.
9. method as claimed in claim 8 wherein is the 60-85% of the microcapsules weight after the spray-drying by encapsulated amount of substance.
10. method as claimed in claim 9 wherein is the 75-80% of the microcapsules weight after the spray-drying by encapsulated amount of substance.
11. the described method of aforesaid each claim, wherein the volume averaging particle diameter (VMD) of the microcapsules after the spray-drying is 5 microns or littler.
12. method as claimed in claim 11, wherein the volume averaging particle diameter (VMD) of spray-dired microcapsules is 2 microns or littler.
13. the described method of aforesaid each claim is that form with the solution in a kind of solvent exists by encapsulated material wherein.
14. the described method of aforesaid each claim, wherein said material is an agricultural chemicals.
15. microcapsules, these microcapsules are by interfacial polycondensation reaction that a kind of active material is encapsulated, then in the presence of polyvinyl alcohol, the product spray-drying of gained are formed, it is characterized in that polyvinyl alcohol is to be present in the interfacial polycondensation course of reaction that forms microcapsules.
16. microcapsules as claimed in claim 15 wherein, are present in the microcapsules with liquid condition by encapsulated material.
17. as claim 15 or 16 described microcapsules, wherein these microcapsules contain 2 kinds of different agricultural chemicals at least.
18. microcapsules as claimed in claim 17, wherein said at least two kinds of different agricultural chemicals are respectively by encapsulated.
19. as claim 17 or 18 described microcapsules, not only contained slow relatively, but also contain the microcapsules of fast relatively rate of release.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB9501017.9A GB9501017D0 (en) | 1995-01-19 | 1995-01-19 | Microencapsulation process and product |
| GB9501017.9 | 1995-01-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1173145A true CN1173145A (en) | 1998-02-11 |
| CN1096882C CN1096882C (en) | 2002-12-25 |
Family
ID=10768235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95197380A Expired - Lifetime CN1096882C (en) | 1995-01-19 | 1995-11-30 | Microencapsulation process and product |
Country Status (14)
| Country | Link |
|---|---|
| EP (1) | EP0804284A1 (en) |
| JP (1) | JP4155411B2 (en) |
| KR (1) | KR19980701505A (en) |
| CN (1) | CN1096882C (en) |
| AU (1) | AU716412B2 (en) |
| BR (1) | BR9510518A (en) |
| CA (1) | CA2209630A1 (en) |
| CZ (1) | CZ212597A3 (en) |
| GB (1) | GB9501017D0 (en) |
| HU (1) | HUT77646A (en) |
| NZ (1) | NZ297679A (en) |
| PL (1) | PL321376A1 (en) |
| UA (1) | UA48160C2 (en) |
| WO (1) | WO1996022159A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101856019A (en) * | 2010-06-04 | 2010-10-13 | 广东省粮食科学研究所 | Novel grain storage pest slow-release pesticide and preparation method thereof |
| CN110602948A (en) * | 2017-03-17 | 2019-12-20 | 美国陶氏益农公司 | Microencapsulated nitrification inhibitor compositions |
| CN110876378A (en) * | 2019-12-11 | 2020-03-13 | 利民化学有限责任公司 | Intelligent microcapsule suspending agent and preparation method thereof |
| WO2020233647A1 (en) * | 2019-05-21 | 2020-11-26 | 江苏龙灯化学有限公司 | Herbicidal composition containing microcapsules, preparation method and application thereof |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9615158D0 (en) * | 1996-07-19 | 1996-09-04 | Dowelanco | Process for preparing storage-stable pesticide dispersion |
| US20020197469A1 (en) | 1998-10-26 | 2002-12-26 | Richard Roy Clikeman | Particles and a process for preparing the same |
| JPH11322587A (en) * | 1998-05-18 | 1999-11-24 | Sumitomo Chem Co Ltd | Microcapsulation of physiologically active substance solid at room temperature and microcapsule composition obtained thereby |
| FR2867395B1 (en) † | 2004-03-15 | 2006-06-16 | Rhodia Chimie Sa | DRY EMULSION, PROCESS FOR PREPARING THE SAME, AND USES THEREOF |
| TWI556737B (en) * | 2011-02-11 | 2016-11-11 | 陶氏農業科學公司 | Improved insecticide formulations |
| BR102012027933A2 (en) * | 2011-11-01 | 2015-11-17 | Dow Agrosciences Llc | stable pesticide compositions |
| CN104661526B (en) | 2012-07-27 | 2018-01-09 | Fmc有限公司 | Clomazone preparation |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1538075A (en) * | 1975-03-24 | 1979-01-10 | Champion Paper Co Ltd | Formation of microcapsules by interfacial cross-linking and microcapsules produced thereby |
| EP0214936B1 (en) * | 1985-09-13 | 1992-07-08 | Ciba-Geigy Ag | Process for producing microcapsules |
| DK352187A (en) * | 1986-07-09 | 1988-01-10 | Monsanto Co | WATER DISPERSIBLE GRANULATE AND PROCEDURES FOR PRODUCING THEREOF |
| US5225118A (en) * | 1990-08-15 | 1993-07-06 | Boise Cascade Corporation | Process for manufacturing polyurea microcapsules and product therefrom |
| US5283153A (en) * | 1992-04-15 | 1994-02-01 | Xerox Corporation | Encapsulated toner processes |
| KR100313589B1 (en) * | 1993-02-09 | 2002-11-29 | 노바티스 아게 | Process for the preparation of microcapsules |
-
1995
- 1995-01-19 GB GBGB9501017.9A patent/GB9501017D0/en active Pending
- 1995-11-30 CA CA002209630A patent/CA2209630A1/en not_active Abandoned
- 1995-11-30 CZ CZ972125A patent/CZ212597A3/en unknown
- 1995-11-30 WO PCT/US1995/015543 patent/WO1996022159A1/en not_active Application Discontinuation
- 1995-11-30 JP JP52224096A patent/JP4155411B2/en not_active Expired - Lifetime
- 1995-11-30 AU AU42900/96A patent/AU716412B2/en not_active Expired
- 1995-11-30 CN CN95197380A patent/CN1096882C/en not_active Expired - Lifetime
- 1995-11-30 HU HU9800551A patent/HUT77646A/en not_active Application Discontinuation
- 1995-11-30 PL PL95321376A patent/PL321376A1/en unknown
- 1995-11-30 BR BR9510518A patent/BR9510518A/en not_active IP Right Cessation
- 1995-11-30 EP EP95941498A patent/EP0804284A1/en not_active Ceased
- 1995-11-30 UA UA97073815A patent/UA48160C2/en unknown
- 1995-11-30 NZ NZ297679A patent/NZ297679A/en not_active IP Right Cessation
- 1995-11-30 KR KR1019970704896A patent/KR19980701505A/en not_active Application Discontinuation
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101856019A (en) * | 2010-06-04 | 2010-10-13 | 广东省粮食科学研究所 | Novel grain storage pest slow-release pesticide and preparation method thereof |
| CN110602948A (en) * | 2017-03-17 | 2019-12-20 | 美国陶氏益农公司 | Microencapsulated nitrification inhibitor compositions |
| CN110602948B (en) * | 2017-03-17 | 2022-04-01 | 美国陶氏益农公司 | Microencapsulated nitrification inhibitor compositions |
| WO2020233647A1 (en) * | 2019-05-21 | 2020-11-26 | 江苏龙灯化学有限公司 | Herbicidal composition containing microcapsules, preparation method and application thereof |
| CN110876378A (en) * | 2019-12-11 | 2020-03-13 | 利民化学有限责任公司 | Intelligent microcapsule suspending agent and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| NZ297679A (en) | 1999-11-29 |
| HUT77646A (en) | 1998-07-28 |
| CZ212597A3 (en) | 1997-12-17 |
| WO1996022159A1 (en) | 1996-07-25 |
| JP4155411B2 (en) | 2008-09-24 |
| AU4290096A (en) | 1996-08-07 |
| KR19980701505A (en) | 1998-05-15 |
| BR9510518A (en) | 1998-07-07 |
| UA48160C2 (en) | 2002-08-15 |
| EP0804284A1 (en) | 1997-11-05 |
| CN1096882C (en) | 2002-12-25 |
| PL321376A1 (en) | 1997-12-08 |
| MX9705484A (en) | 1997-10-31 |
| GB9501017D0 (en) | 1995-03-08 |
| JPH11500346A (en) | 1999-01-12 |
| AU716412B2 (en) | 2000-02-24 |
| CA2209630A1 (en) | 1996-07-25 |
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