CA1332660C - Microencapsulating composition and kit, and process for producing microcapsules - Google Patents

Abstract

MICROENCAPSULATING COMPOSITION AND KIT. AND
PROCESS FOR PRODUCING MICROCAPSULES
ABSTRACT OF THE DISCLOSURE:
An improved microencapsulating composition comprising an emulsifying agent and a compound that is capable of reacting with water to form a membrane but which is not reactive with said emulsifying agent is disclosed. Also disclosed are: a microencapsulating composition comprising said first microencapsulating composition and an active ingredient (e.g. agrichemical, flavor, paint, liquid crystal, repellent against pest and rodent, fertilizer, cosmetic, pigment, ink, attractant, foaming agent, flame retardant, corrosion inhibitor or mold inhibitor) to be microencapsulated; a process for producing microcapsules using either one of the two microencapsulating compositions;
and a kit consisting of the first microencapsulating compo-sitions and a component to be microencapsulated. By mixing the first microencapsulating composition with both a compo-nent to be microencapsulated and a solvent such as water, or by simply mixing the second microencapsulating composition with the solvent, microcapsules that are stable and that have good handling properties can be produced with ease.

Description

-1- 1332~0 MICROENCAPSULATING COMPOSITION AND KIT, AND
PROCESS FOR PRODUCI~G MICROCAPSULES
Background of the Invention:
The present inventlon relates to a microencapsulating composition. More particularly, the present invent~on relates to a microencapsulating composition suitable for long-ter~ storage that may be used in forming microcapsules of a drug such as a commercially available agrlchemical by adding said composition to a spraY liquid together wlth said drug and mixing the components under agitatlon. The present inventlon also relates to a mlcroencapsulating composition that further contalns a component to be microencapsulated, as well as a microencapsulatlng kit consisting of the two klnds of microencapsulatlng composltion.
Mlcroencapsulation technology has been receiving increasing interest because of the several advantages it of~ers, e.g., the potential for modlfying the apparent nature of a substance so as to improve its handling prop-erties, the abllity to stabilize a labile substance, and the potential for reducing the safety hazards associated wlth dangerous substances during use. To take agrichemlcals as an example, the advantages that will be ofiered by micro-encapsulating them may be summarized as follows. Needless to say, efiicacy ls oi prlmary lmportance for agrichemicals, but irom a practical viewpoint the dosage form of an agri~
chemlcal ls no less lmportant. By selectlng an appropriate dosage form, safety for workers is enhanced, potentlal crop inJury can be prevented, and the drug efflcacy can be so controlled that it wlll work ln elther a sustalned or delayed mode. Under these circumstances, actlve research efforts have been made to develop effective dosage forms of agrlchemlcals and mlcroencapsulation, which is one of the accomplishments of these efiorts, has recently attracted increasing lnterest. In mlcroencapsulated agrichemlcals, the active lngredient is coated wlth a membrane so as to not only ralse the level oi safety for the personnel applylng them but also to enable slow release of the drug, thereby enabllng more eiilcient and less labor-lntensive application : . ~ . - . . .

- -2- 1 3 32 ~ 6 or spraylng of the agrichemlcals concerned.
Several methods have been proposed as techniques for microencapsulating agrichemicals. In one proposed method, a pyrethroid insecticide or an organophosphorus insectlcide is microencapsulated with a polyurethane resln (see Japanese Patent Publication No. 53-38325 and Japanese Patent Public Disclosure No. 58-144304); in another method, a slightly water-soluble agrichemical is rnicroencapsulated with poly-urea formed by the interfacial reaction between a polyiso-cyanate solution and an aqueous polyamine solution (seeJapanese Patent Publlc Disclosure No. 62-67003).
These and other techniques that have been proposed to date for encapsulating various ingredients share the follow-ing problems: a complicated separating process is necessary to isolate the microcapsules formed and this adds to the production cost of microcapsules; secondly, the active ingredient might ooze out of the lsolated microcapsules during storage. Thus, many of the microcapsules produced by prior art techniques are not isolated and instead are used in the form of a slurry.
However, a slurry will still have problems such as the tendency of microcapsules to precipitate during storage or to become frozen at low temperatures. Other problems that might be encoutered are disruption o~ microcapsules durlng manufacture and poor dispersibillty of the micro-capsules in the water used as a diluting medlum.
The present inventors thus wanted to refine the conventional techniques of microcapsulation and previously proposed that a composition prepared by intimately mixing an emulsifying agent and a compound capable of reacting with water to form a membrane (said compound is hereunde referred to as a membrane-forming compound) be added, just prior to use, to a solvent such as water together with an active ingredient or drug such as an agrichemical, thereby confining the latter in microcapsules.
The microencapsulating composition prepared by this method involves no inherent problems as long as it is put to use imrnediately after preparation. However, if it is to be used , :
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~ -3- 1332~60 after a certain period of storage, one must anticipate`the problem that gelation and precipitation will occur during that storage period. It also turned out that this composition would not become su~ficiently emulsified in water or other media to accomplish effective microencapsulation.
Summary of the Invention: . . .
The present inventors conducted further studies to solve the aforementioned problems and found that when an emu~sifylng agent and a membrane-formlng compound are so 10 modi~ied that they wlll not react wlth each other or when ~-~
combinations of an emulsifylng agent and a membrane-forming compound that will not react with each other are selected, the resulting mixture will remain stable for an extended period and will allow microcapsules confining an active ingredient to be readily formed when it is added to a spray liquid. The present invention has been accomplished on the basis of this finding.
In one aspect, the present invention provides a ~ ~
microencapsulating composition which is an intimate mixture -o~ two essential components, i.e., an emulsifying agent and a compound that will not react ~ith said emulsi~ying agent and whlch ls capable of reactlng wlth water to form a membrane.
In another aspect, the present lnvention provides a microencapsulating composition that contains as the essen-tial components the iirst microencapsulating composition set forth above and a component to be mlcroencapsulated. Just prlor to use, thls second microencapsulating composltion is added to an approprlate amount of a llquld medium such as water and mixed with stirring to form microcapsules confin-ing the component to be microencapsulated.
In stlll another aspect, the present invention provides a convenient process for producing microcapsules using the first microencapsulating composition described above, as well as a microencapsulating kit that comprises said first microencapsulating compositlon and a component to be microencapsulated.
E~amples of components that may be microencapsulated ~it ' '' , -4- 13~2~
include agrichemicals, flavors, paints, liquid crystals, pest or mouse repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corro-sion inhi~itors, mold inhibitors, etc. These components 5 are added, ~ust prior to use, to a solvent such as water ~-together with the first microencapsulating compositlon, and desired microcapsules confining these components can be obtained by simple procedures.
Detailed Description of the Invention:
It is important for the purposes of the present invention that the emulsifying agent and membrane-forming compound used should not react with each other. To this end, it is necessary to select those combinations of an emulsifying agent and a membrane-forming compound which inherently will not react with each other, or in the case of reactive combinations, the groups that take part in reaction (i.e., reactive groups) must be preliminarily blocked by some chemical method.
Specific examples o~ the emulsifylng agent and membrane-forming compound to be used in the present inven-tion are descrlbed below.
EmulsifyinF Agent (1) Anionic surfactant:
Any anionic surfactants that are commonly employed in emulsification may be used, such as: alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylallylether sulfates, polyoxyethylene-polyoxypropylene block polymer sulfates, alkane sulfonates, dialkyl sulfosuc-cinates, alkylallyl sulfonates, fatty acid salts, Turkey red oil, polyoxyethylene alkylether phosphates, polyoxyethylene alkylallylether phosphates, alkyl phosphates, etc.

(2) Cationic surfactant:
Illustrative cationic surfactants that may be used include: primary amine salts, secondary amine salts, tertiary amine salts, modified amine salts, tetraalkyl quaternary ammonium salts, modified trialkyl quaternary ammonium salts, trialkylbenzyl quaternary ammonium salts, modifled trialkylbenzyl quaternary ammonium salts, .
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13326~0 alkylpyrldinium salts, modified alkylpyridiniUm salts, alkylquinolinium salts, alkylphosphonium salts, alkyl-sulfonium salts, etc.

(3) Nonionic surfactant: :
Illustrative nonionic surfactants that may be used include polyoxyethylene alkyl ethers, polyoxyethylene rosin esters, polyoxypropylene alkyl ethers, polYoxyethylene sorbitan fatty acid esters, polyoxyethylene styrylphenyl ethers, etc. If necessary, these compounds may be chemi-cally blocked by known methods at the terminal primary or secondary OH group in the polyoxyalkylene chain so that they will not react with the isocyanato group in the membrane-forming compound.

(4) Amphoteric surfactant:
Illustrative amphoteric surfactants that may be used include lecithin, alkylaminocarboxylic acid salts, alkyl-dimethy~betaine, alkylhydroxyethylbetaine, etc.
Various types o~ surfactants (1) - (4) may be used in comblnation. A preferred combination is a mixture of anioic and nonionic surfactants. The emulsiiying agents listed above are used in amounts generally ranging from 1 to 50 parts by welght, pre~erably ~rom 3 to 20 parts by weight.
Membrane-Formlng ComPound The membrane-formlng compound to be used ln the present inventlon ls a compound that is capable of reactlng wlth water to ~orm a membrane and may be exemplifled by the followlng:
~1) Isocyanate compound:
Dllsocyanates or polyisocyanates, or urethane pre-polymers that are obtained by reactlng diols or polyols wlthdiisocyanates or polyisocyanates may be used either on their own or as admixtures.
Illustrative dilsocyanates and polylsocyanates lnclude: tolylene dllsocyanate, dlphenylmethane dllso-cyanate, naphthalene dllsocyanate, tolldlne dllsocyanate,hexamethylene dllsocyanate f lsophorone dllsocyanate, xylylene dllsocyanate, hydrogenated dlphenylmethane dllsocyanate, modl~led dlphenylmethane dllsocyanate, , .
. :........ - .

-6- 1332~0 triphenylmethane triisocyanate, undecanetriisocyanate, hexamethylene triisocyanate, lysine ester triisocyanate, polymethylene polyphenyl isocyanate, etc.
Illustrative diols and polyols include: polyhydric alcohols such as ethylene glycol, propylene glycol, hexane-diol, trimethylpropane, glycerin, pentaerythritol, sorbitol, sucrose, etc.; polyether polyols having an alkylene oxide such as ethylene oxide or propylene oxide added to these polyhydric alcohols; polyester polyols such as ethylene adipate, diethylene adipate and butylene adipate; as well as polycarbonate polyols, acrylic polyols and polybutadiene polyols.
(2) Mixture of ketimine with epoxy resin:
A diamine resulting from the reaction between ketimine and water reacts with epoxy to form a polymer film.
(3) Alkyl ~-cyanoacrylate:
A polymer film forms as catalyzed by water.
Among the membrane-forming compounds (1) - (3), the isocyanate compounds (1~ are partlcularly pre~rred.
If the emulsifying agent and membrane-forming compound selected are reactive with each other, the reactive group must be blocked by some method. If the reactive group is the terminal hydroxyl group of a nonionic surfactant, it may be blocked by any one of the known methods including (1) etherification, (2) esterification, (3) urethanation, (4) tertiary hydroxylation, etc.
The etherification method (1) usually involves reacting a nonionic surfactant with an alkyl halide such as methylene chloride or methyl iodide. The esterification method (2) usually involves reacting a nonionic surfactant with a monocarboxylic acid such as acetic acid or propionic acid, a dicarboxylic acid such as oxallc acid, succinic acid, malonic acid, maleic acid or adipic acid, a tri-carboxylic acid such as citric acid, or an acid anhydride o~ these carboxylic acids. The urethanatlon method (3) involves reacting a nonlonic surfactant with a monoiso-cyanate such as methyl isocYanate, ethyl isocyanate, propyl isocyanate or phenyl isocyanate, or a polyisocyanate such ,.

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as tolylene dllsocyanate, xylylene dilsocyanate, diphenyl-methane diisocyanate, or triphenylmethane diisocyanate. The tertiary hYdroxylation method (4) may be performed by adding isobutylene oxide to a nonionic surfactant.
Few surfactants other than nonionics (l.e., anlonics, cationics and amphoterics) have reactive groups and salts having a hydroxyl group such as monoethanolamine salts are few exceptions; the hydroxyl group in these salts may be blocked by the methods described above or they may be converted to metal salts such as Na, K or Ca salts, or ammonium salts.
The emulsifying agent and the membrane-formlng compound may be rendered non-reactive with each other if the latter compound is blocked. For instance, if the membrane-forming compound is a urethane prepolymer, it may be rendered non-reactive by a known method such as reacting the prepolymer with a blocking agent so that it is blocked.
Illustrative blocking agents that may be used in this method include methanol, ethanol, phenol, ethyl mercaptant, hydro-cyanic acid, diethyl malonate, ~-caprolactam, sodium bisulfite, acetylacetone, etc. The urethane polymers blocked with these blocking agents will liberate the iso-cyanato group and restore the membrane-forming capability when heated to their respective cleavage temperature and above. Therefore, ii the substance to be microencapsulated is not resistant to heat, the membrane-forming compound is preferably selected from among those which have low cleavage temperature.
The microencapsulatlng composition of the present invention may be produced by adding 0.05 - 100 parts by weight, preferably 0.5 - 10 parts by weight, of the emulsi-fying agent per part by weight of the membrane-forming compound and mlxing them under stirrlng. Mlxlng under stlrring may be performed with a commonly employed stirrer, and the mixing temperature may be a conventional one.
If the membrane-~ormlng compound and emulsi~ying agent selected are too viscous, they may be mixed with an organic solvent that is added in an appropriate amount.

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-8- 1332~60 Any organic solvent may be used as long as it dissolves an active ingredient (e.g. agrichemical), emulslfying agent, membrane-forming compound, etc. and will not react with the membrane-forming compound. Several examples are listed below: aliphatic hydrocarbons such as heptane, n-hexane, cyclohexane, octane and isooctane; halogenated hydrocarbons such as chloroform, carbon tetrachloride, trichloroethylene and benzene chloride; ketones such as isobutyl ketone, diethyl ketone, methyl ethyl ketone and dipropyl ketone;
esters such as ethyl acetate, butyl acetate, isoamyl acetate and ethyl propionate; ethers such as butyl ether and isopropyl ether; aromatic hydrocarbons such as benzene, toluene, xylene and phenylxylylethane; as well as dimethyl-formamide and dimethyl sulfoxide.
If the substance to be microencapsulated is an agri-chemical, the microencapsulating composition oi the present invention may be used in the following way: a commercial agrichemical is purchased, added to a spray liquid together with the microencapsulating composition, and stirred to form microcapsules con~ining the commercial agrichemical; the resulting solution containing these mlcrocapsules ls sprayed with a spray apparatus.
In accordance wlth a second aspect of the present invention, a microencapsulating composition further contain-ing a substance to be microencapsulated is provided. Toproduce this second microencapsulating composition, 0.05 -100 parts by weight, preferably 0.5 - 20 parts by weight, oi the membrane-iorming compound and 0.05 - 50 parts by weight, pre~erably 0.5 - 10 parts by weight, o~ the emulsifying agent are added to one part by welght oi the component to be microencapsulated, say, an agrichemically active ingredient, and the respective components are mlxed under stirrlng.
Mlxlng under stlrrlng may be periormed wlth a commonly .
employed stlrrer, and the mixinF temperature may be a conventional one.
Any substance may be microencapsulated so long as it will not react wlth the membrane-iormlng compound. Thus, an approprlate agrlchemlcally active ingredlent may be selected ; . .
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: -9~ 1332~0 from among herbicides, fungicides, insecticides, plant growth regulating agents, etc.
It is speculated that microcapsules are formed by the following mechanlsm when the microencapsulatlng composltion of the present invention ls used. First, a spray solutlon of agrichemical is prepared by a conventional method. When the microencapsulatlng composition of the present lnvention is added to the spray solution, the composition is emul-sified and dispersed as tiny droplets not larger than a few microns in the spray solution. Then, these tiny droplets of the composition will coalesce with the droplets or particles in the spray solution that contain the agrichemically actlve ingredient. Thus, new liquid droplets will form that contain both the agrichemically active ingredient and the membrane-forming compound and a membrane is formed at the interfacebetween the newly formed liquid droplets and water, thereby ~enerating microcapsules contalning the agrichemically active ingredlent.
The microencapsulating composition of the present lnvention is generally added ln an amount of 0.02 - 10%
(v/v), pre~erably 0.05 - 2% (vtv), of the spray solutlon contalnlng the component to be mlcroencapsulated.
The thlckness o~ the wall o~ microcapsules ls ad~ust-able by changing the amount of membrane-~orming compound incorporated or the amount of the microencapsulating compo-sitlon of the present invention added.
When an isocyanate based compound is used as the membrane-forming compound in the present invention, the rate at which the wall of microcapsules is formed in dilutlng water may be accelerated wlth a catalyst. The catalyst may be prelimlnarlly incorporated in the microencapsulating composition or it may be added to water to which the micro-encapsulating composltion is added to form microcapsules.
In the case of an agrichemical microencapsulating composi-tion, the catalyst may be incorporated either in that compo-sition or in a solvent to which the composition is added to form agrichemical-containing microcapsules.
The membrane-forming rate can be ad~usted by changing .. . .
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-lo- 1332~
the amount of catalyst added (see Example 25 to be described hereinafter). The catalyst is usually added in an amount ranging from 0.1 to 10 wt% of the microencapsulating compo-sition. Illustrative catalysts that may be used to:acce-lerate the membrane-forming rate include amines such as triethylamine, N,N,N,N-tetramethyl-1,3-butanediamine, lauryldimethylamine and triethylenediamine, and organotin compounds such as dibutyltin dilaurate, dibutyltin-di(2-ethylhexoate) and stannous oleate. These catalysts may be used either on their own or as admixtures.
I~ a urethane prepolymer is used as the membrane-forming compound, the membrane-forming rate can also be adjusted by changing the hydrophilic-lipophilic balance (HLB) of the urethane prepolymer (see Example 24 to be given hereinafter).
The present invention offers the following many advantages. The mlcroencapsulating composition according to its first aspect is suitable for long-term storage-and microcapsules containing a component to be microencapsulated can be readily iormed by merely adding said component and composition to water or some other liquid medium ~ust prior to use. The llquld preparation contalnlng these micro-capsules is ready for immediate use. Accordlng to the second aspect of the present invention, a microencapsulating composition whlch additionally contains a component to be microencapsulated, ior example, an agrichemlcal ls provlded (l.e., an agrichemical microencapsulating composition), and this second microencapsulating composition is suitable for long-term storage as in the case of the iirst microen-capsulating composltion. Furthermore, an agrichemicalmicrocapsule preparation containing an agrichemically active ingredient can be readlly formed by merely addlng sald second composition to a liquid spray medlum, and the result-ing spray solution ls ready for lmmediate application.
Thus, the agrichemical mlcrocapsule preparation oi the present inventlon oiiers the advantage that lt iulillls the prevlously recognlzed need for the spraylng oi agrlchemlcals in a saie, efflclent and labor-savlng iashlon.

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--11- 1~32~60 The present invention is hereinafter described in greater detall with reference to Examples and Comparative Examples. It should, however, be noted that these examples are intended for illustrative purposes only and should not be taken as limiting the scope of the present invention.
It will be apparent to one skilled in the art that various modifications and changes can be made to the dlsclosure in the specification without departing from the spirit and object of the present invention.
In the Examples and Comparative Examples, the follow-ing test methods were used.
Storage Stability Test:
A microencapsulating composition was examined visual-ly in the as-prepared state and after storage at 40C for 1 week or 3 months. A sample that was free from coloration, precipitation and gelation was rated "goodn.
Emulsion StabilitY Test:
Part of the microencàpsulating composition to be sub~ected to the storage stability test was diluted 1,000 times with hard water (hardness scale 3) at 20-C and the stability of the resulting emulsion was evaluated visually after the passage oi 2 hours.
Quantitatlve Determlnatlon of Isocyanato GrouD:
A solution of 0.1 ~ dl-n-butylamine in acetone was prepared. A portion (25 mQ) of the solution was charged into a conical ilask, to which a l,000-fold dllutlon o~ a mlcroencapsulatlng composltlon of the present lnventlon was added ln an amount of exactly 10 g. After standing for 20 minutes at room temperature, 100 mQ of isopropyl alcohol was added and titration wlth 0.1 N HCl was conducted wlth Bromophenol Blue being used as an indicator. The proportion of the unreacted lsocyanato group was calculated and the percent reactlvity oi the lsocyanato group was determined on the basls of the calculation.
All the "parts~ in whlch the respective components used in the Examples and Comparative Examples are expressed are "parts by weight~.
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-12- 1332~6~
ExamPle 1 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 70 parts of POLYGROUT*0-1 (urethane prepolymer produced by Daiichi Kogyo Seiyaku Co., Ltd.) and 20 parts of xylene were mixed under stirring to prepare a microencapsulating composition (which is abbreviated herein-after as a "composition').
Exam~le 2 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethYlene distyrylphenol ether (17.~ mol ethylene oxide zdded) and ~0 parts of calcium dodecylbenzenesulfon~te, ~0 parts of POLYGROUT O-l and AO parts of xylene were mixed under agitation to prepare a composition.
E~am~le 3 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethyIene distyrylphenol ether (17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 20 parts of POLYGROUT O-l and 70 parts of xylene were mixed under agitation to prepare a composition.
Com~arative Exam~le 1 Ten parts of an emulsifying agent consisting of 50 parts of polyoxyethYlene distyrylphenol ether not blocked at the terminal (17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 20 parts of POLYGROU~ O-l and 70 parts of ~ylene were mixed under agitation to prepare a composltion.
This composition and those which were prepared in Examples 1 - 3 were subjected to a storage stability test and an emulsion stability test. The results are shown in Table 1.
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-13- 1332~
Table l As l week 3 months prepared storage stabillty 0 0 .. 0 Ex. l emulsion stability 0 0 0 storage stability 0 0 0 Ex. 2 emulsion stability 0 Ex. 3 storage stability emulsion stability 0 0 0 __ white pre- white pre-storage stability 0 cipitate cipitate Exmpi formed formed .
emulsion stability X
0: good X: poor : As is clear from Table l, the compositions prepared in Examples l - 3 were stable but in the composition of Comparati~e Example l which used a nonionic surfactant whose terminal group was not blocked, said surfactant reacted with the urethane prepolYmer to cause not only precipitation but also marked reduction in emulsion stability.
E2am~1e 4 A commercial pyridaphenthion emulsion (O~CK R*
. Emulsion produced by Mitsui Toatsu Chemical, Inc.) was diluted 500 fold with water. To the resulting dilution, each of the compositions prepared in Examples l - 3 and Comparative Example l was added in an amount of 0.1% ~v/v) after storage at 40-C for 3 months, and mixed under stirring to prepare diluted compositions. Alumlnum disks (7 cm in dia.) were submerged in the diluted compositions for l minute. The recovered disks were dried and placed in a thermostatic chamber at 30-C, where they were stored for a predetermined period. Thereafter, the disk were taken out of the thermostatic chamber and the amount of pyridaphen-thion adhering to the disks was measured by gas chromatog-raphy. The residual amount of pyridaphenthion was * Trade Mark .

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-14- 133~
determined in terms of relative value, with the value measured right after immersion being taken as laO. If the compositions prepared in Examples 1 - 3 were in the form of microcapsules confining pyridaphenthion, the compound would be released from the capsules according to their disintegra-tion rate, causing a gradual decrease in the residual amount of the compound. Therefore, the residual amount of pyrida-phenthion will serve as an index for the formation of micro-capsules. The results are shown in Table 2.
Table 2 As lmmersed 3 days 6 days ¦10 days Example 1 100% 95 71 45 Example 2 lOo 88 60 33 Example 3 100 8a 52 30 ~ 100 80 O O b~

The data given in Table 2 to show the residual effect of the insecticide ~pyridaphenthion) makes it clear that the microencapsulating compositions prepared in accordance with the present invention.successfullY microencapsulated a commercial insecticide.
ExamPle 5 ~ .
Orange oil used as a flavor was added to a 0.1% (v/v) aqueous solution of Tween 20 to form a suspension at a concentration of 5% (v/v). A composition prepared as in Example 1 was weighed in the same volume as that of the orange oil and mixed with the suspension under stirring, thereby forming a suspension of microcapsules confining the orange oil.
ExamPle 6 4-~romo-bisphenol used as a flame-retardant was added to a 0.1~ (v/v) aqueous solution of TW~EN* 20 to form a suspension at a concentration of 10% (v/v). A composition prepared as in Example 1 was weighed in the same volume as that of the 4-bromo-bisphenol and mixed with the suspension * Trade Mark .,, `~

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ExamPle 7 Forty parts of pyridaphenthion, 10 parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of DIKSSOL MG 100* (urethane prepolymer produced by Daiichi Kogyo Seiyaku Co,. Ltd.) and 40 parts of xylene were mixed under stirring to prepare a composition.
Example 8 Forty parts of pyridaphenthion, lO parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 5 parts of DIKSSOL MG 100 and 45 parts of xylene were mixed under stirring to prepare a composition.
ExamPle 9 Forty parts of pyridaphenthion, 10 parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 3 parts ofDI~ssoL M~ 10~0, and 47 parts of xylene were mixed under stirring to prepare a composition.
Com~arative ExamPle 2 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal (25 mol ethylene oxide added), 3 parts of ~IKSSOL MG 100, and 47 parts of xylene were mixed under stirring to prepare a composition.
This composition and those which were prepared in Examples 7 - 9 were subJected to a storage stability test and an emulsion stability test. The results are shown in 3~ Table 3.

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-16- 1332~0 Table 3 As 1 week 3 months storage stability 0 Ex. 7 emulsion stability 0 0 0 .
Ex. 8 storage stability 0 emulsion stability 0 0 0 storage stability 0 0 0 Ex. 9 emulsion stability 0 0 white pre- white pre- L~
Comp storage stability 0 clpitate cipltate Ex. 2 formed formed emulsion stability X
0: ~ood X: poor As is clear from Table 3, the compositions prepared in Examples 7 - 9 were stable but in the composition of Comparatlve Example 2 which used a nonionic surfactant whose terminal group was not blocked, said surfactant reacted with the urethane prepolymer to cause not only precipitation but also marked reduction in emulsion stability.
ExamDle 10 Compositions that were prepared as in Examples 7 - 9 were stored at 40-C for 3 months and therea~ter diluted 1000 ~old. For each of the dlluted composltlons, the resldual amount o~ pyrldaphenthion was determined as in Example 4.
The results are shown in Table 4.
Table 4 ¦AS immersed 13 days 16 days ¦10 da~s ¦
Example 7 lOOS 9260 43 Example 8 100 8655 26 Example 9 100 8350 33 EXaDP1e 2 100 6714 O

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,, ~ ,~ , ; , ~ . --17- ~ 33 ~ ~ ~n The data in Table 4 shows that even after long-term storage, the compositions of the present invention success-fully provided drug-containing microcapsule preparations on being mixed with diluent water alone ~ust prior to use.
ExamPle ll Four parts of a polynactin complex, lO parts of an emulsifYing agent consisting of 50 parts of an acet2te of polyoxyethylene nonylphenol ether (30 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, lO parts of DIKSSOL MD 100 (urethane prepolymer produced by Daiichi Kogyo Seiyaku Co., Ltd.), 0.2 parts of N-lauroylglutamic acid dibutylamide, and 69.8 parts o~ machine oil were mixed under stirring to prepare a composition in the form of a suspension. When subjected to the same tests as in Comparative Example l, this composition showed good results in terms of both storage stability and emulsion stability.
ExDeriment Half a part of Azoic Diazo Component 22 (Kako Blue VR
Salt produced by Showa Chemical Co-, Ltd.), lO parts of an emulsifying agent consisting of 50 parts of an acetate ester of polyoxyethylene nonylphenol ether (20 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, ~ -lO parts of Dikssol MG lOO, and 79.5 parts of xylene were mixed under stirring to prepare a liquid composition. In a separate step, 0.5 parts of ~-naphthol (product of Wako Pure Chemical Industries, Ltd.), lO parts of an emulsifying agent consisting of 50 parts of an acetate ester of polyoxy-ethylene nonylphenol ether (20 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, and 89.5 parts of xylene were mixed under stirrlng to prepare a composi-tlon. One milliliter each of the two compositions w2s added to l,OOO mQ of hard water (hardness scale 3) at 20-C and stirred. Fifteen minutes later, the emulsion in the diluted mixture turned red. This means that Azoic Diazo Component ~2 and ~-naphthol in the two compositions reacted with each other, and provides an indirect proof of the fact that the two emulsions coalesced in water to form microcapsules * Trade Mark ~

confining the active ingredients.
ExamPle 12 Preparation of a composition capable of simple produc-tion of a microcapsule preparation confining as t~e main component soYbean oil useful as an enamel remover:
Eighty parts of soybean oil (main component), 10 parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecyl-benzenesulfonate, and 10 parts of Dikssol MG 100 were mixed under stirring to prepare a composition.
ExamPle 13 Preparation of a composition capable of simple produc-tion of a microcapsule preparation confinlng as themain component rutile titanium dioxide having improved fluidity and being useful as a pigment:
A compositlon was prepared as in Example 12 except that rutile titanium dioxide was used as the main component.
Exam~le 14 Preparation of a composition capable of simple produc-tion of a mlcrocapsule preparatlon conflning as the main component citronella which is useful as a flavor:
A composition was prepared as in Example 12 except that citronella was used as the main component.
ExamPle 15 Preparation of a composition capable of simple produc-tion of a microcapsule preparation conflning as the main component 4-bromo-ethane having improved maskIng property and being useful as a flame-retardant:
A composition was prepared as in Example 12 except that 4-bromo-ethane was used as the main component.
ExamPle 16 Preparation of a composition capable of simple produc-tion of a microcapsule preparation confining as themaln component a cholesterlc llquld crystal useful ln llquid-crystal prlntlng:

~.. , .. ... .. , ,, .. ... . ............ ~ . . . - .

' ' .

--19- 1332~gO
A composition was prepared as in Example 12 except that a cholesteric liquid crystal consisting of 20 parts of cholesterin chloride and 80 parts of cholesterin nonanoate was used as the main component. :-Testing The compositions prepared in Examples 12 - 16 were subjected to the same tests as in Comparative Example 1 and the results were satisfactory with all samples in terms of both storage stability and emulsion stability.
lC Example 17 Twelve parts of a polynactin complex, 10 parts of an emulsifying agent composed of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (35 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate.
15 10 parts of Polygrout 0-1, and 68 parts of benzene chloride were mixed under stirring to prepare a composition. The results of a storage stability test and an emulsion stabil-ity test conducted on this composition are shown in Table 5.
Com~arative Exam~le 3 A composition was prepared as in Example 17 except that a mixture consisting of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal (35 mol ethylene oxide added) and 50 parts of calcium dodecyl-benzenesulfonate was used as an emulsifying agent. The results of a storage stability test and an emulsion stabil-ity test conducted on this composition are shown in Table 5.
Table 5 As 1 week 3 months storage stability 0 0 0 Ex. 17 emulsion stability 0 0 0 .
white pre- white pre-Ex. 3 storage stability 0 cipitate formed emulsion stabilitY X
0: good X: poor ~ .... ... ..

.. . . .
~;,'' ~.
,. ~

` 133~6~0 As isi clear from Table 5, the compositions prepared in Example 17 was stable but in the composition of Comparative Example 3 which used a nonionic surfactant whose terminal was not blocked, said surfactant reac~ed with the urethane prepolymer to cause not only precipitation but also marked reduction in emulsion stability.
ExamPle 18 Two parts of etofenplocks, 10 parts of an emulsifying agent consisting of 50 parts of methyl ether of polyoxy-ethylene nonylphenol ether (15 mol ethylene oxide added)and 50 parts of calcium dodecylbenzenesulfonate, 15 parts of Polygrout 0-3 (urethane prepolymer produced by Daiichi Kogyo Seiyaku Co., Ltd.) and 73 parts of xylene were mixed under stirring to prepare a compositlon. Thls composltion was sub~ected to a storage stabllity test and an emulsion stability test and the results were satisfactory both in the as-prepared state and after storage for either 1 week or 3 months.
Exam~le 19 FortY parts of pyridaphenthion, 10 parts of an emulsiiying agent conslsting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (35 mol ethylene oxide added) and calcium dodecylbenzenesulfonate, 10 parts of tolylene diisocyanate and 40 parts of xylene were mixed under stlrring to prepare a composition. The results of a storage stablllty test and an emulsion stabllity test conducted on thls compositlon are shown in Table 6.
Com~arative ExamPle 4 A composition was prepared as in Example 19 except that a mixture consistlng of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal (35 mol ethylene oxide added) and 50 parts of calcium dodecyl-benzenesulfonate was used as an emulslfying agent. The results o~ a storage test and an emulsion test conducted on this composition are shown in Table 6.

,' :, ~
: ~ . ................ .

~ .

-21- 1332SSO `
Table 6 prepared l week 3 months storage stability 0 0 . 0 Ex. l9 emulsion stabillty 0 0 white pre- white pre-storage stability 0 cipitate clpitate Comp. formed ~ormed Ex. 4 emulsion stability X
0: ~ood X: poor As is clear from Table 6, the composition of Example l9 was stable but in the composltlon of Comparative Example 4, the nonionlc surfactant reacted with tolylene dilso-cyanate, causlng not only preclpltation but also marked reductlon ln emulslon stablllty.
Exam~le 20 ~ orty parts oi tripropyl isocyanate (TPIC), lO parts oi an lsobutylene oxlde adduct o~ polyoxyethylene nonyl-phenol ether (lO mol ethylene oxlde added), 15 parts oi 1,4-butane dllsocyanate and 35 parts of kerosene were mlxedunder stlrrlng to prepare a composition. This composltlon showed satlsfactory storage stability and emulsion stability.
ExamPle 21 Fifty parts oi dichlorvos, 5 parts of ethyl cyano-acrylate, lO parts oi an acetate oi polyoxyethylenebenzyl-phenol ether (30 mol ethylene oxide added) and ~5 parts oi ~ylene were mlxed under stlrrlng to prepare a compositlon.
Thls compositlon showed satlsfactory storage stability and emulsion stablllty.
ExamPle 22 Ten parts oi oxadiazon, 3 parts o~ ketimine obtalned by reactlng ethylenediamlne with acetone, 6 parts of epoxy resln (dlglycidyl ether o~ bisphenol A), lO parts oi an emulsiiylng agent conslsting oi 50 parts of an acetate ester oi polyoxyethylene dlstyrylphenol ether (35 mol ethylene oxide added) and 50 pa~ts of calclum dodecylbenzene-sulionate, and 71 parts of xylene were mixed under stirring ,.
' .

~ :
; ~ -.~ .

-22- 1332~6~ ~
to prepare a composition.
This composition showed satisfactory storage stability and emulslon stability.
ExamPle 23 Forty parts of diazinon, 20 parts of an emulsifying agent consisting of 50 parts of methyl ether of polyoxy-ethylated castor oil (50 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of Monotac (urethane prepolymer produc~d by Daiichi Kogyo Seiyaku Co., Ltd.) and 30 parts of a solvent system composed of 50 parts of xylene and 50 parts of benzene chloride were mixed under stirring to prepare a composition. This compo-sitlon was subjected to a storage stabllity test and an emulslon stability test and the results were satlsfactory both ln the as-prepared state and after storage for 1 week or 3 months.
After the passage of 3 months at room temperature, the percent reactlvlty of lsocYanato group was determined at given intervals by the method already described for estimat-lng the membrane-formlng speed of microcapsules.
The results of measurements of the percent reactlvlty oi lsocyanato group are shown ln Table 7.
Table 7 ¦Time passed (min) ¦ 0 ¦ 5 15 ¦ 30 ¦Reactivit~ (X) 1 1 10 ~ ~

The data in Table 7 and examination under electron mlcroscope showed that when the microencapsulating composi-tion oi the present invention was diluted with water, the - membrane-iorming compound reacted with water to iorm microcapsules.
ExamDle 24 Eight parts of tetradiion, 20 parts oi an emulsifying agent conslsting oi 50 parts oi an acetate oi polyoxy-ethylene distyrylphenol (25 mol ethylene oxide added) and :~:

. . - .. - . - . . . i , . . :

~332~

50 parts of calcium dodecylbenzenesulfonate, l0 parts of Polygrout W-l (hydrophilic urethane prepolymer produced by Daiichi Kogyo Seiyaku Co., Ltd.) and 62 parts of xylene were mixed under stlrring to prepare a composition. The:percent reactivity of isocyanato group in this composition was measured as in Example 23 to estimate the membrane-formlng speed of microcapsules. The results are shown in Table 8.
Table 8 Time passed (min) O 5 15 ~ 30 Reactlvity (%) 0 6~ 100 lOO

Obviously, the composition of Example 24 enabled membrane formation at a faster rate than the composition of Example 23. This suggests the possibility of accelerating membrane formation by using a more hydrophilic urethane prepolymer as the membrane-forming compound. In other words, the membrane-forming speed can be ad~usted by chang-ing the hydrophilic-lipophilic balance (HLB) of the urethane prepolymer. The composition of Example 24 was satisfactory ln terms of both storage stabillty and emulslon stablllty.
ExamDle 25 Forty parts of glyphosate, l0 part of an emulslfylng agent conslstlng of 50 parts of the methyl urethanated product of polyoxyethylene distyrylphenol ether (lS mol ethylene oxide added) and 50 parts of calcium dodecyl-benzenesulfonate, l0 parts of a urethane prepolymer formed by reaction between polyoxypropylene glycerin ether and hexamethylene diisocyanate, O, 0.l, l or 5 parts of dibutyl-tin dllaurate (catalyst), and xylene to make a total amountof lOO parts were mlxed under stlrrlng to prepare four klnds of composltion havlng the catalyst added in varying amounts.
In order to estimate the membrane-forming speed of mlcrocapsules for each composltlon, the percent reactivity ` .
of isocyanato group was measured by the same method as employed in Example 23. The results are shown in Table 9.

~.~ . . .
. ~ . .
'~

~ . ~
i~ .
~ ~ .

-24- ~3326~
Table 9 Amount of Time passed (min) catalyst (%) 05 15 30 0 05 14 25;
Reactivity 0.1 024 50 82 (X) O--54--85 89 O 83 9S lOo As is clear from Table 9, the membrane-forming speed of microcapsules can be ad~usted by changing the amount of catalyst added.
Examination under electron microscope showed that satisfactory microcapsules had been generated from the four compositlons of interest. The results of a storage stabil-ity test and an emulsion stability test conducted on these compositions were satisfactory both in the as-prepared state and after storage for 1 week or 3 months.
ExamPle 26 Twenty parts of triadimefon, 20 parts of diphenyl-methane diisocyanate, 1 part of lauryl dimethylamine (catalyst), 10 parts o~ dimethyl~ormamide, 5, 10 or 20 parts o~ an emulslfying agent consisting o~ 50 parts of a propio-lS nate of polyoxyethylene tristyrylphenol ether (25 molethylene oxide added) and 50 parts of calcium dodecyl-benzenesulfonate, and xylene to make a total amount of 100 parts were mixed under stirring to prepare three kinds of composition having the emulsi~ying agent added in varying amounts. Each of these compositions was diluted 1,000 folds with water and emulsified at 25-C. Thirty minutes later, the resulting microcapsules were examined under electron microscope and their average particle slze was investigated.
The results are shown in Table 10.

25- 133266~
Table 10 _ Amount of emulsifying agent Averae particle size (%) (~m) ~.

The above results show that the higher the content of the emulsifying agent, the smaller the particle size of the microcapsules produced.
The results of a storage stability test and an emul-sion stability test conducted on the three compositions of interest were satisfactory both in the as-prepared state and after storage for 1 week or 3 months.
Use Ten grams of the compositlon prepared in Example 2~
was added to 10 Q of water and stirred. After being allowed to stand for ca. 15 minutes, the suspension of microcapsules was charged into a commercial stainless steel shoulder sprayer and sprayed in an adequate amount over cabbage seedlings potted ln a greenhouse. No clogging occurred durlng the applicatlon and the coverage and wetting of cabbage wlth the applled suspenslon was satisfactory.

._.... . . .

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, . :

~ 1332660 SUPPLEMENTARY DISCLOSURE

As mentioned in the principal disclosure, the microencapsulating composition with which the invention is concerned contains as essential components an emulsifying agent and a compound capable of reacting with water to form a membrane, but not reactive with the emulsifying agent.
Examples of suitable membrane-forming compounds that are described in the principal disclosure include isocyanate compounds, such as diisocyanates, polyisocyanates and ure-thane prepolymers which are obtained by reacting diols or polyols with diisocyanates or polyisocyanates.
It has now been found that polyisocyanate compounds which have a cationic group in their molecule are specially usefulas membrane-formil~g compounds. Such polyisocyanate com-pounds can be readily produced by a process which comprises reacting a polyisocyanate compound having at least three isocyanato groups with an alcohol having a tertiary amino group so as to introduce the tertiary amino group and then quaternizing the polyisocyanate compound by reaction with an alkylating agent such as alkylsulfuric acid (e.g.
dimethylsulfuric acid or diethylsulfuric acid)) or an alkyl halide (e.g. methyl iodide, propyl iodide, methyl chloride, propyl chloride, methyl bromide or propyl bromide). Poly-isocyanate compounds that can be used in producing the membrane-forming compound defined above include: tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diiso-cyanate, isophorone diisocyanate, xylylene diisocyanate, ;~
hydrogenated diphenylmethane diisocyanate, modified diphenylmethane diisocyanate, triphenylmethane triiso-cyanate, undecane triisocyanate, hexamethylene triiso~
cyanate, polymethylene polyphenyl isocyanate, as well as compounds obtained by reacting the above-mentioned com-pounds with polyhydric alcohols, polyether polyols, polyester polyols, polycarbonate polyols, acrylic polyols or polybutadiene polyols. The alcohol having a textiary . ; - 26 -^` 1332660 amino group may be exemplified by diethylethanolamine, dimethylethanolamine, dimethylhexanolamine, dimethyl-butanolamine, etc.
While there are many polyisocyanate compounds having a cationic group in the molecule that can be prod-uced by the procedure described above, the following poly-isocyanate compounds (a) - (f) are particularly preferred:
(a) A polyisocyanate compound having the following structural formula (hereinafter referred to as urethane prepolymer A):

NHcooc2H4-Nl -C2H5 C2H5S4 rOCONH~CH3 CH2CH3 CH3-(cH2)5-cH-cH2-cH=cH (CH2)7 ~H2 NCO
rOCONH ~ CH3 CH -(CH ) -CH-CH -CH=CH-(CH2)7-Coo-C ~H
NCO
rOCONH ~ CH3 3 2)5 CH CH2-CH=CH-(CH2) -COO-CH

(b) A polyisocyanate compound having the following . .
structural formula (hereinafter referred to as urethane prepolymer B):

NCO

HC ~ NCO
\ fH3 \ ~ NHCOOC2H4-N~-CH3~Cl~) .

. .
.

.
. . .

, . .

(c) A polyisocyanate compound having the following structural formula (hereinafter referred to as urethane prepolymer C):

H3C~`~N/ \N/~N~cooc2H4-N~3-cH3~cl~3 0// \N/ ~0 CH3 (d) A polyisocyanate compound having the following struc-tural formula (hereinafter referred to as urethane prepolymer D) ~CH20CO-NH-(CH2)6-NC
H C -C -CH OCo-NH-(cH2)6-Nco f 3 \ CH2oco-NH-(cH2)6-NHcooc2H4-lN -CH3-Cl (e) A polyisocyanate compound having the following struc-tural formula (hereinafter referred to as urethane prepolymer E) CIH3 NCO

CH2o-(cH2cHo)2co-NH ~ C 3 ~Ho-(cH2cHo)2co-NH~cH3 ¦ CH3 NCO :~ ::
CHO-(CH2CHO)2cO-NH ~ 3 ~ ;
¦ CH3 NCO
CHo-(cH2cHo)2co-NH ~ CH3 f2 5 ~ fH3 NHCOOC2H4-N~-cH3~ Br~ :

CH2o-(cH2cHo)2co-NH ~ CH3 2 5 .~ :

133~6fiO
(f) A polyisocyanate compound having the following struc-tural formula (hereinafter referred to as urethane prepolymer F) fH3 CH20-(CH2CHO)3-(CH2CHO)3-NH-(CH2)6-NCO

H5c2-c-cH2o-(cH2cHo)3-(cH2cHo)3-NH-(cH2)6-Nco \ f fH3 CH2o-(cH2cHo)3-(c~2cHo)3-NHcooc2H4-lN -CH3 Cl The following additional Examples and Comparative Examples further illustrate the invention. The test methods used in these Examples and Comparative Examples are the same as those described in the principal disclosure. Similarly, all the "parts" in which the respective components are used are expressed as "parts by weight".
Example 27 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 70 parts of urethane prepolymer A
and 20 parts of xylene were mixed under stirring to prepare a solution composition.
Example 28 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 50 parts of urethane prepolymer A
and 40 parts of xylene were mixed under agitation to prepare a composition.
Example 29 Ten parts of an emulsifying agent consisting of 50 parts of an acetate of polyoxyethylene distyrylphenol ether (17.5 mol ethylene oxide added) and 50 parts of calcium . - 29 -~'''' ' ......
.~ ~ ' ' :;

.-.. -..... . - . . :

13326~
dodecylbenzenesulfonate, 20 parts of urethane prepolymer A
and 70 parts of xylene were mixed under agitation to prepare a composition.
Comparative Example 5 Ten parts of an emulsifying agent consisting of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal t17.5 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 20 parts of urethane pre-polymer A and 70 parts of xylene were mixed under agitation to prepare a composition.
This composition and those which were prepared in Examples 27 - 29 were subjected to a storage stability test and an emulsion stability test. The results are shown in Table 11.
Table 11 prepared 1 week 3 months Ex ~7 storage stability emulsion stability storage stability O O O
Ex. 2~ :
emulsion stability Ex 29 storage stability emulsion stability O O O
::
white pre- white pre-Comp. storage stability O cipitate cipitate Ex. 5 formed formed emulsion stabilitY X - -O: good X: poor ~ ~ ' As is clear from Table 11, the compositions prepared in Examples 27-29 were stable but in the composition of Com-parative Example 5 which used a nonionic surfactant whose ~ -terminal group was not blocked, the surfactant reacted with the urethane prepolymer to cause not only precipitation but also marked reduction in emulsion stability.

,J~
~ ,.. .

., ~. " - .

13326~
Example 30 A commercial pyridaphenthion emulsion (Ofunack Emul-sion produced by Mitsui Toatsu Chemical, Inc.) was diluted 500 fold with water. To the resulting dilution, each of the compositions prepared in Examples 27-29 and Comparative Exam-ple 5 was added in an amount of 0.1~ (v/v) after storage at 40C for 3 months, and mixed under stirring to prepare di-luted compositions. Aluminum disks (7 cm in dia.) were sub-merged in the diluted compositions for 1 minute. The recov-ered disks were dried and placed in a thermostatic chamber at 30C, where they were stored for a predetermined period.
Thereafter, the disks were taken out of the thermostatic chamber and the amount of pyridaphenthion adhering to the disks was measured by gas chromatography. The residual amount of pyridaphenthion was determined in terms of relative value, with the value measured right after immersion being taken as 100. The results are shown in Table 12.
Table 12 As immersed 3 days 6 days 10 days , Example 27 100% 89 63 35 Example 28 100 84 51 23 Example 29 100 82 48 31 Comparative 100 58 12 0 Example 5 _ The data given in Table 12 to show the residual ef-fect of the insecticide (pyridaphenthion) makes it clear that the microencapsulating compositions prepared in accordance with the present invention successfully microencapsulated a commercial insecticide.
Example 31 Orange oil used as a flavor was added to a 0.1% (v/v) aqueous solution of TWEEN 20 (trade mark) to form a suspen-sion at a concentration of 5~ (v/v). A composition prepared as in Example 27 was weighed in the same volume as that of , , .

. ~ - . .. . ... . -the orange oil and mixed with the suspension under stirring, thereby forming a suspension of microcapsules confinlng the orange oil.
Example 32 4-Bromo-bi~phenol used as a flame-retardant was added to a 0.1% (v/v) aqueous solution of TWEEN 20 to form a sus-pension at a concentration of 10% (v/v). A composition pre-pared as in Example 27 was weighed in the same volume as that of the 4-bromo-bisphenol and mixed with the suspension under stirring, thereby forming a suspension of microcapsules con-fining 4-bromo-bisphenol.
Example 33 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of an acetate of poly-oxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 -~ -~
parts of urethane prepolymer B and 40 parts of xylene were mixed under stirring to prepare a composition.
Example 34 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of an acetate of poly-oxyethylene distyrylphenol ether (25 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 5 parts of urethane prepolymer s and 45 parts of xylene were mixed under stirring to prepare a composition.
Example 35 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of an acetate of poly- ~
oxyethylene distyrylphenol ether (25 mol ethylene oxide ~-added) and 50 parts of calcium dodecylbenzenesulfonate, 3 ``~
parts of urethane prepolymer B and 47 parts of xylene were mixed under stirring to prepare a composition.
Comparative Example 6 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of polyoxyethylene dis-tyrylphenol ether not blocked at the terminal (25 mol ethyl-13326fi~

ene oxide added), 3 parts of urethane prepolymer B and 47 parts of xylene were mixed under stirring to prepare a compo-sition.
This composition and those which were prepared in Examples 33-35 were subjected to a storage stability test and an emulsion stability test. The results are shown in Table 13.
Table 13 prepared 1 week 3 months Ex.33 storage stability emulsion stability 0 0 O
,, Ex. 34 storage stability O 0 emulsion stabilitY
storage stability O O
Ex.35 emulsion stability O O 0 .
white pre- white pre-Comp. storage stability 0 cipitate cipitate Ex. 6 formed formed emulsion stability X
O: good X: poor As is clear from Table 13, the compositions prepared in Examples 33-35 were stable but in the composition of Com-parative Example 6 which used a nonionic surfactant whose terminal group was not blocked, the surfactant reacted with the urethane prepolymer to cause not only precipitation but also marked reduction in emulsion stability.
Example 36 Compositions that were prepared as in Examples 33-35 were stored at 40C for 3 months and thereafter diluted 1000 fold. For each of the diluted compositions, the residual amount of pyridaphenthion was determined as in Example 30.
The results are shown in Table 14.

;., ., , ., .:: :
. .

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133~6~0 Table 14 As immersed 3 days 6 days 10 days Example 33 100% 90 56 42 Example 34 100 88 55 28 Example 35 100 85 52 32 Comparative 100 62 13 0 The data ln Table 14 shows that even after long-term storage, the compositions of the present invention success-fully provided drug-containing microcapsule preparations on being mixed with diluent water alone just prior to use.
Example 37 :: :
Four parts of flufenoxuron, 10 parts of an emulsi-fying agent consisting of 50 parts of an acetate of polyoxy-ethylene nonylphenol e~her (20 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of urethane prepolymer C, 0.2 parts of N-lauroylglutamic acid dibutylamide, and 69.8 parts of xylene were mixed under stirring to prepare a composition in the form of a suspen-sion. When subjected to the same tests as in Comparative Example 5, this composition showed good results in terms of both storage stability and emulsion stability.
Example 38 Half a part of Azoic Diazo Component 22 (Kako Blue VR
Salt produced by Showa Chemical Co., Ltd.), 10 parts of an emulsifying agent consisting of 50 parts of an acetate ester of polyoxyethylene nonylphenol ether (20 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of urethane prepolymer C and 79.5 parts of xylene were mixed under stirring to prepare a liquid composition. In a separate step, 0.5 parts of B-naphthol (product of Wako Pure Chemical Industries, Ltd.), 10 parts of an emulsifying agent consisting of 50 parts of an acetate ester of polyoxyethylene nonylphenol ether (20 mol ethylene oxide added) and 50 parts ~; '' ' .
.

.! ' . :

1 3 ! 2 6 ~ ~

of calcium dodecylbenzenesulfonate, and 89.5 parts of xylene were mixed under stirring to prepare a liquid composition.
One milliliter each of the two liquid compositions was added to 1,000 ml of hard water (hardness scale 3) at 20C and stirred. Fifteen minutes later, the emulsion in the diluted -mixture turned red. This means that Azoic Diazo Component 22 and ~-naphthol in the two compositions reacted with each other, and provides an indirect proof of the fact that the two emulsions eoalesced in water to form microcapsules con-fining the active ingredients.
Example 39 Preparation of a composition capable of simple production of a microcapsule preparation confining as the main compo-nent soybean oil useful as an enamel remover:
Eighty parts of soybean oil (main eomponent), 10 parts of an emulsifying agent consisting of 50 parts of an aeetate of polyoxyethylene distyrylphenol ether ~25 mol ethylene oxide added) and 50 parts of caleium dodeeylbenzene-sulfonate, and 10 parts of urethane prepolymer C were mixed under stirring to prepare a eomposition.
Example 40 Preparation of a eomposition eapable of simple produetion of a mieroeapsule preparation eonfining as the main eompo-nent rutile titanium dioxide having improved fluidity and being useful as a pigment:
A composition was prepared as in Example 39 except that rutile titanium dioxide was used as the main eomponent.
Example 41 Preparation of a eomposition eapable of simple produetion of a mieroeapsule preparation eonfining as the main eompo~
nent eitronella whieh is useful as a flavor:
A eomposition was prepared as in Example 39 exeept that eitronella was used as the main eomponent.
Example 42 Preparation of a composition capable of simple produetion of a microeapsule preparation confining as the main eompo-nent 4-bromo-ethane having improved masking property and being useful as a flame-retardant:

. .', . '. . ";, ' ~ .. '.. ' . ~. .:: . ~ ' A composition was prepared as in Example 39 except that 4-bromo-ethane was used as the main component.
Example 43 Preparation of a composition capable of simple production of a microcapsule preparation confining as the main compo-nent a cholesteric liquid crystal useful in liquid-crystal printing: -~
A composition was prepared as in Example 39 except that a cholesteric liquid crystal was used as the main compo-nent.
Example 44 The compositions prepared in Examples 39-43 were subjected to the same tests as in Comparative Example 5 and the results were satisfactory with all samples in terms of both storage stability and emulsion stability.
Example 45 Twelve parts of a polynactin complex, 10 parts of an emulsifying agent composed of 50 parts of an acetate of poly-oxyethylene distyrylphenol ether (35 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of urethane prepolymer D and 68 parts of benzene chlo-ride were mixed under stirring to prepare a composition. The results of a storage stability test and an emulsion stability test conducted on this composition are shown in Table 15.
Comparative Example 7 A composition was prepared as in Example 45 except that a mixture consisting of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal (35 mol ethylene oxide added) and 50 parts of calcium dodecylbenzene-sulfonate was used as an emulsifying agent. The results of a storage stability test and an emulsion stability test con- -ducted on this composition are shown in Table 15.

, "`'` `' ' ' ' : ' ': ' "'' ' : ' ~: : : ` , ~ ,'' ' . ~:

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, .. ~ , .",. . - , : - : - . :: `, -1332~0 Table 15 = rIe storage stability O O O
Ex. 45 emulsion stability O O O
white pre- white pre-storage stability O cipitate cipitate Ex 7 formed formed emulsion stability 0: good X: poor As is clear from Table 15, the compositions prepared in Example 4 5 was stable but in the composition of Compara-tive Example 7 which used a nonionic surfactant whose termi-nal was not blocked, the surfactant reacted with the urethane prepolymer to cause not only precipitation but also marked reduction in emulsion stability.
Example 46 Two parts of etofenplocks, 10 parts of an emulsifying agent consisting of 50 parts of methyl ether of polyoxy-ethylene nonylphenol ether (15 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 15 parts of urethane prepolymer E and 73 parts of xylene were mixed under stirring to prepare a composition. This composition was subjected to a storage stability test and an emulsion stabil-ity test and the results were satisfactory both in the as-prepared state and after storage for either 1 week or 3 months.
Example 47 Forty parts of pyridaphenthion, 10 parts of an emul-sifying agent consisting of 50 parts of an acetate of poly-oxyethylene distyrylphenol ether (35 mol ethylene oxide added) and calcium dodecylbenzenesulfonate, 10 parts of ure-thane prepolymer F and 40 parts of xylene were mixed under ,,,~ ~1.

.;

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stirring to prepare a composition. The results of a storage stability test and an emulsion stability test conducted on this composition are shown in Table 16.
Comparative Example 8 A composition was prepared as in Example 47 except that a mixture consisting of 50 parts of polyoxyethylene distyrylphenol ether not blocked at the terminal ~35 mol ethylene oxide added) and 50 parts of calcium dodecylbenzene-sulfonate was used as an emulsifying agent. The results of a storage test and an emulsion test conducted on this composi-tion are shown in Table 16.

Table 16 As ¦ 1 week 3 months prepared Ex. 47 storage stability _ _ emulsion stability O O O
white pre- white pre-Comp. storage stability O cipitate cipitate Ex. 8 formed formed emulsion stability X X
0: good X: poor As is clear from Table 16, the composition of Example 47 was stable but in the composition of Comparative Example 8, the nonionic surfactant reacted with urethane prepolymer F, causing not only precipitation but also marked reduction in emulsion stability.
Example 48 Forty parts of tripropyl isocyanate (TPIC), 10 parts of an isobutylene oxide adduct of polyoxyethylene nonylphenol ether (10 mol ethylene oxide added), 15 parts of urethane prepolymer C and 35 parts of kerosene were mixed under stirring to prepare a composition. This composition showed satisfactory storage stability and emulsion stability.

~ , l33266n Example 49 Forty parts of diazinon, 20 parts of an emulsifying agent consisting of 50 parts of methyl ether of polyoxy-ethylated castor oil (50 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of ure-thane prepolymer D and 30 parts of a solvent system composed of 50 parts of xylene and 50 parts of benzene chloride were mixed under stirring to prepare a composition. This composi-tion was subjected to a storage stability test and an emul-sion stability test and the results were satisfactory both in the as-prepared state and after storage for 1 week or 3 months.
After the passage of 3 months at room temperature, the percent reactivity of isocyanato group was determined at given intervals by the method already described for estima-ting the membrane-forming speed of microcapsules.
The results of measurements of the percent reactivity of isocyanato group are shown in Table 17.

Table 17 Time passed (min) 0 5 15 30 Reactivity (%) 0 ~ 38 88 ..

The data in Table 17 and examination under electron microscope showed that when the microencapsulating composi-tion of the present invention was diluted with water, the membrane-forming compound reacted with water to form micro-capsules.
Example 50 Forty parts of glyphosate, 10 parts of an emulsifying agent consisting of S0 parts of the methyl urethanated prod-uct of polyoxyethylene distyrylphenol ether (15 mol ethylene oxide added) and 50 parts of calcium dodecylbenzenesulfonate, 10 parts of a urethane prepolymer B, 0, 0.1, 1 or 5 parts of ~"' .

~ t^r 1332~
., dibutyltin dilaurate (catalyst), and xylene to make a total amount of 100 parts were mlxed under stirring to prepare four kinds of composition having the catalyst added in varying amounts.
In order to estimate the membrane-forming speed of microcapsules for each composition, the percent reactivity of isocyanato group was measured by the same method as employed in Example 49. The results are shown in Table 18-Table 18 Amount of Time passed (min) catalyst (%) 0 5 15 30 _ 0 0 6 14 28 React vity 085 97 lO0 As is clear from Table 18, the membrane-forming speed of microcapsules can be adjusted by changing the amount of catalyst added.
Examination under electron microscope showed that satisfactory microcapsules had been generated from the four compositions of interest. The results of a storage stability test and an emulsion stability test conducted on these compo- ` `
sitions were satisfactory both in the as-prepared state and after storage for 1 week or 3 months.
Example 51 Twenty parts of triadimefon, 20 parts of urethane prepolymer F, 1 part of lauryl dimethylamine (catalyst), 10 parts of dimethylformamide, 5, 10 or 20 parts of an emul-sifying agent consisting of 50 parts of a propionate of poly-oxyethylene tristyrylphenol ether (25 mol ethylene oxide added) and S0 parts of calcium dodecylbenzenesulfonate, and xylene to make a total amount of 100 parts were mixed under .' ~ .

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,......... ~ . ., , : , :.: . ~ : : .- ., , ,. -. . , . , . ~. . . .

stirring to prepare three kinds of composition having the emulsifying agent added in varying amounts. Each of these compositions was diluted 1,000 folds with water and emul-sified at 25C. Thirty minutes later, the resulting micro-capsules were examined under electron microscope and their average particle size was investigated. The results are shown in Table 19.
Table 19 Amount of emulsifying agentAverage particle size (%) (~m) The above results show that the higher the content of the emulsifying agent, the smaller the particle size of the microcapsules produced.
The results of a storage stability test and an emul- ;
sion stability test conducted on the three compositions of interest were satisfactory both in the as-prepared state and after storage for 1 week or 3 months.
Use Ten grams of the composition prepared in Example 47 was added to 10 1 of water and stirred. After being allowed to stand for ca. 15 minutes, the suspension of microcapsules was charged into a commercial stainless steel shoulder sprayer and sprayed in an adequate amount over cabbage seed-lings potted in a greenhouse. No clogging occurred during the application and the coverage and wetting of cabbage with the applied suspension was satisfactory.

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Claims (62)

1. A microencapsulating composition contain-ing as essential components a compound capable of reacting with water to form a membrane, and a non-ionic surfactant having active hydroxy groups which are blocked so as to not react with the membrane-forming compound.

2. A microencapsulating composition according to claim 1, wherein the membrane-forming compound is at least one member selected from the group consisting of diisocyanates, polyisocyanates and urethane prepolymers.

3. A microencapsulating composition according to claim 1, wherein the membrane-forming compound comprises a mixture of ketimine and an epoxy resin.

4. A microencapsulating composition according to claim 1, wherein the membrane-forming compound is al alkyl .alpha.-cyanoacrylate.

5. A microencapsulating composition according to claim 1, which further comprises at least one emulsifying agent selected from the group consisting of anionic, cationic and amphoteric surfactants.

6. A process for producing microcapsules, which comprises mixing under stirring a composition containing a component to be microencapsulated, a microencapsulating composition as defined in claim 1, and water, the component to be microencapsulated being a substance which does not react with the membrane-forming compound.

7. A process according to claim 6, wherein the membrane-forming compound is at least one member selected from the group consisting of diisocyanates, polyisocyanates and urethane prepolymers.

8. A process according to claim 6, wherein the membrane-forming compound comprises a mixture of ketimine and an epoxy resin.

9. A process according to claim 6, wherein the membrane-forming compound is an alkyl .alpha.-cyanoacrylate.

10. A process according to claim 7, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of anionic, cationic and amphoteric surfactants.

11. A process according to claim 6, wherein the component to be microencapsulated is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibitors.

12. A process according to claim 6, wherein the component to be microencapsulated is an agrichemically active ingredient.

13. A microcapsule containing a micro-encapsulated composition as defined in claim 1 and an active ingredient which is microencapsulated therein and does not react with the membrane-forming compound.

14. A microcapsule according to claim 13, wherein the membrane-forming compound is at least one member selected from the group consisting of diisocyanates, polyisocyanates and urethane pre-polymers.

15. A microcapsule according to claim 13, wherein the membrane-forming compound comprises a mixture of ketimine and an epoxy resin.

16. A microcapsule according to claim 13, wherein the membrane-forming compound is an alkyl .alpha.-cyanoacrylate.

17. A microcapsule according to claim 13, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of anionic, cationic and amphoteric surfactants.

18. A microencapsulate according to claim 13, wherein the active ingredient is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibitors.

19. A microencapsulating kit consisting of a composition containing a component to be micro-encapsulated and a microencapsulating composition as defined in claim 1, the component to be micro-encapsulated being a substance which does not react with the membrane-forming compound.

20. A microencapsulating kit according to claim 19, wherein the membrane-forming compound is at least one member selected from the group consist-ing of diisocyanates, polyisocyanates and urethane prepolymers.

21. A microencapsulating kit according to claim 19, wherein the membrane-forming compound comprises a mixture of ketimine and an epoxy resin.

22. A microencapsulating kit according to claim 19, wherein the membrane-forming compound is an alkyl .alpha.-cyanoacrylate.

23. A microencapsulating kit according to claim 19, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of anionic, cationic and amphoteric surfactants.

24. A microencapsulating kit according to claim 19, wherein the component to be micro-encapsulated is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibitors.

25. A microencapsulating kit according to claim 19, wherein the component to be micro-encapsulated is an agrichemically active ingredient.

CLAIMS SUPPORTED BY THE
SUPPLEMENTARY DISCLOSURE

26. A microencapsulating composition according to claim 1, wherein the membrane-forming compound is a polyisocyanate compound having a cationic group in its molecule.

27. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

28. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

29. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

30. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

31. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

32. A microencapsulating composition according to claim 26, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

33. A microencapsulating composition according to claim 26, which further comprises at least one emulsifying agent selected from the group consisting of cationic and amphoteric surfactants.

34. A process for producing microcapsules, which comprises mixing under stirring a composition containing a component to be microencapsulated, a microencapsulating composition as defined in claim 30, and water, the component to be microencapsulated being a substance which does not react with the membrane-forming component.

35. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

36. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

37. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

38. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

39. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

40. A process according to claim 34, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

41. A process according to claim 34, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of cationic and amphoteric surfac-tants.

42. A process according to claim 34, wherein the component to be microencapsulated is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibitors.

43. A process according to claim 34, wherein the component to be microencapsulated is an agrichemically active ingredient.

44. A microcapsule containing a micro-encapsulating composition as defined in claim 26 and an active ingredient which is microencapsulated therein and does not react with the membrane-forming compound.

45. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cvanate compound of the formula:

46. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cyanate compound of the formula:

47. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cyanate compound of the formula:

48. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cyanate compound of the formula:

49. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cyanate compound of the formula:

50. A microcapsule according to claim 44, wherein the membrane-forming compound is a polyiso-cyanate compound of the formula:

51. A microcapsule according to claim 44, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of cationic and amphoteric surfactants.

52. A microencapsulate according to claim 44, wherein the active ingredient is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibi-tors.

53. A microencapsulating kit consisting of a composition containing a component to be micro-encapsulated and a microencapsulating composition as defined in claim 26, the component to be micro-encapsulated being a substance which does not react with the membrane-forming compound.

54. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

55. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

56. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

57. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

58. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

59. A microencapsulating kit according to claim 53, wherein the membrane-forming compound is a polyisocyanate compound of the formula:

60. A microencapsulating kit according to claim 53, wherein the microencapsulating composition further comprises at least one emulsifying agent selected from the group consisting of cationic and amphoteric surfactants.

61. A microencapsulating kit according to claim 53, wherein the component to be micro-encapsulated is selected from the group consisting of agrichemicals, flavors, paints, liquid crystals, repellents, fertilizers, cosmetics, pigments, inks, attractants, foaming agents, flame retardants, corrosion inhibitors and mold inhibitors.

62. A microencapsulating kit according to claim 53, wherein the component to be micro-encapsulated is an agrichemically active ingredient.