JP6331264B2 - Core-shell capsule and method for producing the same - Google Patents

Description

  The present invention relates to a core-shell capsule that is inexpensive and excellent in physical and chemical stability of inclusions.

  Core-shell capsules are used in a wide range of fields such as industrial use, pharmaceutical use, and food use.

  Particularly in industrial applications, it is used as a curing agent such as an epoxy resin, a pressure-sensitive color former for a pressure measurement film, and a photosensitive / thermal recording paper.

  Conventional core-shell type capsules have been produced mainly by interfacial polymerization at the oil layer / water layer interface or solid phase / liquid layer interface because of the structure in which a shell that physically becomes a barrier is formed on the core surface.

  However, amine compounds and thiol compounds, which are widely known as epoxy resin curing agents, are amphiphilic and difficult to form an interface with oil and water, making core-shell capsules containing amine compounds and thiol compounds in the core. Was difficult.

  In view of the above circumstances, an object of the present invention is to provide an inexpensive core-shell capsule encapsulating an amphiphilic amine compound or thiol compound, and a method for producing the same.

The present invention provides the following inventions.
[1] Formed from a core portion containing a compound having two or more functional groups in the molecule that nucleophilically react with acid chloride, and a shell portion containing a polymer obtained by reacting the compound with two or more acid chlorides Core-shell capsules.
[2] A core-shell type capsule formed from a core part containing a compound having two or more amine groups in the molecule, and a shell part containing a polyamide resin obtained by reacting the compound with a bifunctional or higher acid chloride. .
[3] The core according to [1], wherein a shell part is formed by adding a compound having two or more functional groups capable of nucleophilic reaction with an acid chloride or a solution thereof into the acid chloride or the solution thereof. A method for producing a shell-type capsule.
[4] After dropping a compound having two or more functional groups capable of nucleophilic reaction with acid chloride or a solution thereof in a poor solvent, the acid chloride or the solution thereof is dropped to form a shell portion. [1 ] The manufacturing method of the core-shell type capsule described in the above.
[5] The core according to [1], wherein a shell part is formed by spraying a compound having a functional group capable of nucleophilic reaction with an acid chloride at least two or a solution thereof on the acid chloride or the solution thereof. A method for producing a shell-type capsule.
[6] After spraying a compound having two or more functional groups capable of nucleophilic reaction with acid chloride or a solution thereof in a poor solvent, the acid chloride or the solution thereof is dropped to form a shell portion. [1 ] The manufacturing method of the core-shell type capsule described in the above.
[7] A dissolution step in which a compound having two or more functional groups capable of nucleophilic reaction with acid chloride is dissolved in a molecule until the solubility is saturated while heating in a poor solvent, and the resulting solution is cooled, The method for producing a core-shell capsule according to [1], comprising: a crystallization step for crystallizing a compound; and a dropping step for forming a shell portion by dropping acid chloride into the obtained mixture.
[8] The method for producing a core-shell type capsule according to [7], wherein the crystal is pulverized after the crystallization step and then the acid chloride is dropped.
[9] The method for producing a core-shell capsule according to [7], wherein after the dissolving step, seed crystals having an average particle size of 10 μm or less are dispersed and the solution is cooled while stirring.

The reason why the above-described problem can be solved by the core-shell capsule of the present invention is not necessarily clear, but the present inventors consider as follows.
That is, a compound having two or more functional groups capable of nucleophilic reaction with acid chloride (for example, an amine compound or a thiol compound) and acid chloride undergo a nucleophilic reaction, and the reactivity is very high. By using chloride, a shell is formed on the surface of the core before the substance contained in the core is dissolved into the liquid layer that becomes a reaction field with the acid chloride. By using as a shell a polymer in which a compound having two or more functional groups capable of nucleophilic reaction with an acid chloride and a bifunctional or higher acid chloride is polymerized, the polymer itself can be dissolved and dropped into the liquid layer. It is thought that it can be prevented.

  According to the present invention, it is possible to provide a core-shell type capsule that is inexpensive and excellent in physical and chemical stability of inclusions, and a method for producing the same.

FIG. 3 is a diagram showing a CT scan image of the microcapsule 1 produced in Example 1.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  The core-shell type capsule of the present embodiment is a polymer obtained by reacting a core part containing a compound having two or more functional groups in the molecule that nucleophilically react with acid chloride, and the compound and bifunctional or more acid chloride. And a shell portion including

  Examples of the functional group that undergoes a nucleophilic reaction with an acid chloride include a primary amine group, a secondary amine group, a thiol group, and a hydroxyl group. However, the functional group is not particularly limited as long as it is a functional group that undergoes a nucleophilic reaction with an acid chloride. In addition, a compound having two or more functional groups in the molecule can be used even if the functional group is single or a compound in which different functional groups are mixed, and a mixture of compounds having different functional groups is used. You can also.

  Examples of the compound having two or more primary amine groups include ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, 1,2-diaminopropane, 1,2-diaminoethane, 1,4-diaminobutane, 1,5- Diaminopentane, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1, Aliphatic diamines such as 2-diaminocyclohexane; o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3 , 3'-Diaminodi Phenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis (4-amino-3,5-dimethylphenyl) methane, bis (4-amino-3,5-diisopropylphenyl) methane, 3, 3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl Sulfide, 3,3′-diaminodiphenyl ketone, 3,4′-diaminodiphenyl ketone, 4,4′-diaminodiphenyl ketone, 2,2-bis (3-aminophenyl) propane, 2,2 ′-(3 4'-diaminodiphenyl) propane, 2,2-bis (4-amino) Enyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,3 ′-(1 , 4-phenylenebis (1-methylethylidene)) bisaniline, 3,4 ′-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 4,4 ′-(1,4-phenylenebis (1- Methylethylidene)) bisaniline, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, bis (4- (3-amino) Phenoxy) phenyl) sulfide, bis (4- (4-aminophenoxy) phenyl) sulfide, bis (4- (3-aminophenoxy) phenyl) sulfone , Aromatic diamines such as bis (4- (4-aminophenoxy) phenyl) sulfone and 3,5-diaminobenzoic acid; aliphatic polyamines such as MPMD and metaxylylenediamine manufactured by DuPont Japan; manufactured by Sun Techno Chemical Co., Ltd. A skeleton having a polyether skeleton typified by Jeffamine EDR148; isophoronediamine, 1,3-bisaminomethylcyclohexane, 1-cyclohexylamino-3-aminopropane, 3-aminomethyl-3,3,5-trimethyl-cyclohexyl An alicyclic polyamine such as an amine, a diamine having a norbornane skeleton represented by NBDA manufactured by Mitsui Chemicals, Inc .; a polyamide amine having an amino group at the molecular end of the polyamide; 2,5-dimethyl-2,5-hexamethylenediamine , Mensendiamine, 1,4-bisamino Jeffirmin D230, Jeffermin D400, Jeffermin D2000, Jeffermin D4000 manufactured by Sun Techno Chemical Co., which has skeleton of ropylpiperazine, 1,4-bis (2-amino-2-methylpropyl) piperazine, polypropylene glycol (PPG) However, the present invention is not limited to these examples.

  In addition, compounds having two or more primary and secondary amine groups in the molecule can be used, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, iminobispropylamine, methyliminobispropyl. An amine or the like can be used.

  Examples of the compound having two or more secondary amine groups include N, N′-diisopropyl-2,4,6-triethyl-1,3-benzenediamine, N, N′-di-s-butyl-2,4. , 6-triethyl-1,3-benzenediamine, N, N′-di-2-pentyl-2,4,6-triethyl-1,3-benzenediamine, N, N′-diisopropyl- (2,4- Diethyl-6-methyl-1,3-benzenediamine), N, N′-di-s-butyl- (2,4-diethyl-6-methyl-1,3-benzenediamine), N, N′-diisopropyl -(4,6-diethyl-2-methyl-1,3-benzenediamine), N, N'-di-s-butyl- (4,6-diethyl-2-methyl-1,3-benzenediamine), N, N′-di (2-naphthyl)-(4,6-diethi -2-methyl-1,3-benzenediamine), N, N′-di (2-cyclopentenyl)-(2,4-diisopropyl-6-methyl-1,3-benzenediamine), N, N′— Diisopropyl- (2-methyl-4,6-di-s-butyl-1,3-benzenediamine), N, N′-di-s-butyl- (2-methyl-4,6-di-s-butyl) -1,3-benzenediamine), N, N′-di (1-cyclopropylethyl)-(2-methyl-4,6-di-s-butyl-1,3-benzenediamine), N, N ′ -Di (3,3-dimethyl-2-butyl)-(2-ethyl-4-isopropyl-6-methyl-1,3-benzenediamine), N, N'-diisopropyl-2,4,5,6- Tetra-n-propyl-1,3-benzenediamine, N, N′-di (3- Nten-2-yl) -2,4,5,6-tetra-n-propyl-1,3-benzenediamine and N, N′-di (4-hexyl) -2,3,5,6-tetraethyl- 1,4-benzenediamine, N, N′-diisopropyl- (2,4-diethyl-6-methyl-1,3-benzenediamine), N, N′-diisopropyl- (4,6-diethyl-2-methyl) -1,3-benzenediamine) and mixtures thereof; N, N′-di-s-butyl- (2,4-diethyl-6-methyl-1,3-benzenediamine), N, N′-di- s-Butyl- (4,6-diethyl-2-methyl-1,3-benzenediamine), N, N′-diisopropyl-2,2′-methylenebis (6-n-propylbenzeneamine), N, N ′ -Di-s-butyl-2,2'-methylene Bis (3,6-di-n-propylbenzenamine), N, N′-di (2,4-dimethylbenzyl) -2,2′-methylenebis (5,6-dihexylbenzenamine), N, N ′ -Diisopropyl-3,3'-methylenebis (2,6-di-n-butylbenzenamine), N, N'-di (2,4-dimethyl-3-pentyl) -3,3'-methylenebis (2, 6-di-n-butylbenzenamine), N, N′-diisopropyl-4,4′-methylenebis (2,6-diethylbenzenamine), N, N′-di-s-butyl-4,4′-methylenebis (2,6-diethylbenzenamine), N, N′-di (2-hexyl) -4,4′-methylenebis (2,6-diethylbenzenamine), N, N′-di (1-naphthylethyl) -4 , 4'-Methylenebis 2,6-diisopropylbenzeneamine), N, N′-dicyclobutyl-4,4′-methylenebis (2-isopropyl-6-methylbenzenamine), N, N′-di (1-penten-3-yl)- 4,4′-methylenebis (2-methyl-6-tert-butylbenzeneamine), N, N′-di-s-butyl-4,4 ′-(1,2-ethanediyl) bis (2,6-diethylbenzene) Amine), N, N′-di (1-cyclopentylethyl) -4,4 ′-(1,2-ethanediyl) bis (2,6-diethylbenzenamine), N, N′-di (2-ethylbutyl)- 4,4 ′-(1,2-ethanediyl) bis (2,6-diisopropylbenzenamine), N, N′-di (10-undecenyl) -2,2′-methylenebis (3,4,6-tripentyl) Benze Amine), N, N′-di (4-heptyl) -3,3′-methylenebis (2,5,6-trihexylbenzenamine), N, N′-dimentyl-4,4′-methylenebis (2, 3,6-trimethylbenzenamine), N, N′-dibenzyl-4,4′-methylenebis (2,3,4,6-tetramethylbenzenamine), N, N′-diisopropyl-4,4′-methylenebis Examples include (2,6-diethylbenzeneamine) and N, N′-di-s-butyl-4,4′-methylenebis (2,6-diethylbenzeneamine), but are not limited thereto. .

  Examples of the compound having two or more thiol groups include 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3- Butanedithiol, 1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane, dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide, Examples thereof include methyl-substituted dimercaptodiethyl sulfide, dimethyl-substituted dimercaptodiethyl sulfide, dimercaptodioxaoctane, 1,5-dimercapto-3-oxapentane, and 1,4-benzenethiol.

Moreover, the compound which has a thiol group represented by following formula (1)-(5) can also be used suitably.

Examples of the polythiol include the following general formula (I)

(Wherein 4 R's each independently represents an alkylene group having 1 to 12 carbon atoms), the following general formula (II)

(Wherein, each of three Rs independently represents an alkylene group having 1 to 12 carbon atoms, and R ¹ represents an alkyl group having 1 to 6 carbon atoms), the following general formula (III)

(In the formula, two Rs each independently represents an alkylene group having 1 to 12 carbon atoms, R ² represents an alkylene group having 1 to 6 carbon atoms,

(Wherein n represents an integer of 1 to 3 and Y represents a hydrogen atom or a methyl group)), a compound represented by the following general formula (IV)

(Wherein R ³ is an alkylene group having 3 to 12 carbon atoms,

(Wherein n represents an integer of 1 to 3), a compound represented by the following general formula (V)

(In the formula, four R ^{4 s} are each independently an alkylene group having 1 to 6 carbon atoms,

(Wherein n represents an integer of 1 to 3)), the following general formula (VI)

(Wherein R ¹ represents an alkyl group having 1 to 6 carbon atoms, and three R ^{4 s} are each independently the same as R ⁴ in formula (V)), Formula (VII)

(In the formula, R ² has the same meaning as R ² in formula (III)), and the like, but is not limited thereto.

  The compounds having two or more functional groups capable of nucleophilic reaction with the acid chlorides exemplified above can be used alone or in combination.

  Examples of the bifunctional or higher functional acid chloride include dichloride, trichloride, tetrachloride and the like.

  Dichlorides include oxalic acid dichloride, malonic acid dichloride, succinic acid dichloride, fumaric acid dichloride, glutaric acid dichloride, adipic acid dichloride (adipoyl chloride), muconic acid dichloride, sebacic acid dichloride, nonanoic acid dichloride, undecanoic acid dichloride, etc. 1,2-cyclopropanedicarboxylic acid dichloride, 1,3-cyclobutanedicarboxylic acid dichloride, 1,3-cyclopentanedicarboxylic acid dichloride, 1,3-cyclohexanedicarboxylic acid dichloride, 1,4-cyclohexanedicarboxylic acid Alicyclic dicarboxylic acid dichlorides such as dichloride; phthalic acid dichloride, isophthalic acid dichloride, terephthalic acid dichloride, 1,4-naphthalene Dicarboxylic acid dichloride, 1,5- (9-oxofluorene) dicarboxylic acid dichloride, 1,4-anthracene dicarboxylic acid dichloride, 1,4-anthraquinone dicarboxylic acid dichloride, 2,5-biphenyldicarboxylic acid dichloride, 1,5-biphenylene Dicarboxylic acid dichloride, 4,4′-biphenyldicarbonyl chloride, 4,4′-methylene dibenzoic acid dichloride, 4,4′-isopropylidene dibenzoic acid dichloride, 4,4′-bibenzyldicarboxylic acid dichloride, 4, 4'-stilbene dicarboxylic acid dichloride, 4,4'-transidicarboxylic acid dichloride, 4,4'-carbonyldibenzoic acid dichloride, 4,4'-oxydibenzoic acid dichloride, 4,4'-sulfonyldibenzoic acid dichloride 4 , 4′-dithiodibenzoic acid dichloride, p-phenylene diacetic acid dichloride, 3,3′-p-phenylene dipropionic acid dichloride, and the like, but are not limited thereto. .

  As trichloride and tetrachloride, trimellitic acid chloride, pyromellitic acid chloride, oxydiphthalic acid chloride, biphenyl-3,4,3 ′, 4′-tetracarboxylic acid chloride, benzophenone-3,4,3 ′, 4 ′ -Tetracarboxylic acid chloride, diethyl pyromellitic diacyl chloride, diphenylsulfone-3,4,3 ', 4'-tetracarboxylic acid chloride, 4,4'-(2,2-hexafluoroisopropylidene) phthalic acid chloride, m (p) -phenyl-3,4,3 ′, 4′-tetracarboxylic acid chloride, cyclobutane-1,2,3,4-tetracarboxylic acid chloride, 1-carboxymethyl-2,3-5 cyclopentanetricarboxylic acid Examples include acid chloride, but are not limited thereto. There.

  The acid chlorides exemplified above can be used alone or in combination.

  The core part may contain a compound having two or more functional groups capable of nucleophilic reaction with acid chloride in the molecule, or the compound may be contained together with other components. As other components, any substance that is stable against a compound having two or more functional groups in the molecule that nucleophilically react with acid chloride can be used.

  For example, if a compound having one functional group that nucleophilically reacts with acid chloride in the molecule is used as the other component, the polymer forming the shell portion becomes flexible and the heat resistance is lowered. This is preferable because the physical property value and cross-linking density of the shell can be adjusted according to (pressure-sensitive type, heat-sensitive type, etc.) and form (shell crushing type, core material oozing type, etc.).

Monofunctional amines, monofunctional thiols, and the like are listed as compounds having one functional group in the molecule that nucleophilically reacts with acid chloride.
Monofunctional amines include 1-aminooctane, 2-aminooctane, 1-aminodecane, aniline, o-anisidine, m-anisidine, 4-aminoperatrol, 2'-aminoacetophenone, 3'-aminoacetophenone, 4'- Aminoacetophenone, o-aminodiphenyl, 1-naphthylamine, 9-aminophenanthrene, o-, m-, p-toluidine, o-, m-, p-chloroaniline and isomer mixtures, o-, m-, p- Bromoaniline and isomeric mixtures, o-, m-, p-trifluoromethylaniline and isomeric mixtures, 2,4-, 2,6-, 3,4- and 3,5-dimethyl-, -dichloro- , -Dibromo- and -diethylaniline and isomer mixtures, pt-butylaniline and the like.

  Monofunctional thiols include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 5-phenyl-2-benzoxazole thiol, 6-methyl-2-benzoxazole thiol, 4-amino-5- Methyl-2-pyridinethiol, thiophenol, 2-mercaptobenzyl alcohol, 2-phenoxythiophenol, 3-mercaptophenanthrene, 1-hexanethiol, 1-octanethiol, 2-methyl-1-butanethiol, 2- Methyl-2-butanethiol, aryl mercaptan, cyclohexyl mercaptan, thiophenol, phenethyl mercaptan, 2-ethylthiophenol, 4-methoxybenzothiophenol, 2-naphthalenethiol, mercaptoimi Tetrazole, mercaptothiazole, mercaptotriazole, mercaptothiadiazole, mercaptooxadiazole, mercaptobenzimidazole, mercaptobenzoxazole, may be mentioned mercaptobenzothiazole, and their derivatives.

  In addition, as other components, inorganic or organic compound fine particles such as silicone, methyl methacrylate-butadiene-styrene (MBS) copolymer, styrene-acrylate copolymer, and polyimide can be used. Use of these fine particles is preferable because stress relaxation during curing of a curable resin such as an epoxy resin as a binder can be performed after the core is released.

  In addition, fine particles of a substance having a specific gravity of 1.5 or more such as silica, noble metal, transition metal, etc. can be used as the other component. Use of these fine particles is preferable because the specific gravity of the core can be adjusted, and inhibition of shell formation due to floating of the core in an organic solvent as a capsule formation site can be prevented. In addition, it is more preferable that the surface of the fine particles is hydrophobized with a silane coupling agent or the like because dispersibility in inclusions is improved.

  The particle size of the fine particle component is preferably an average particle size of 1/5 or less of the target core size. If the average particle size is larger than this, the fine particle component may protrude from the core surface and hinder shell formation. Although the minimum particle diameter of microparticles | fine-particles is not specifically limited, When the dispersibility to an inclusion and the handleability are considered, the particle size of 50 nm or more is preferable.

  Moreover, when the core part contains other components, the content is preferably 80% by volume or less, and more preferably 70% by volume or less, from the viewpoint of improving the density of the shell part.

  The core-shell capsule of the present embodiment can be produced by, for example, adding a compound having two or more functional groups that nucleophilically react with acid chloride into the acid chloride to form a shell portion. . The above compound and acid chloride may be used alone, as a mixture with other compounds, or in a solution state.

  When the above compound is a solid, it may be added to the acid chloride as it is, or may be added as a liquid after heating. Moreover, when the said compound is a liquid state or a solution state, it can be thrown into an acid chloride by dripping or spraying.

  The above compound can be dropped with a dropper or the like. The hole diameter at the tip of the dropper is appropriately selected according to the desired capsule diameter. This method can be suitably used for producing capsules having a capsule diameter of about 0.5 to 20 mm.

  Moreover, spraying of the above compound can be performed by spraying or the like. This method can be suitably used for producing capsules having a capsule diameter of about 0.05 to 0.5 mm.

  In addition, when the compound is solid or has a high viscosity, it can be used in a solution state, or the spray tip can be warmed with a heater or the like to reduce the viscosity, thereby enabling good spraying.

  Further, when the compound is in a liquid state, it can be solidified by spraying it in a room cooled below the freezing point of the compound or a refrigerant such as liquid nitrogen and put into an acid chloride or acid chloride solution. In addition, the solidified compound can be added by, for example, trapping with a mesh or the like placed in the above room or a refrigerant and immersing the whole mesh in an acid chloride or acid chloride solution before melting.

  Also, the above compound is dissolved in a solvent soluble in acid chloride and acid chloride solution, and a solution in which solids such as fine particles are dispersed is dropped into acid chloride or an acid chloride solution using a poor solvent for the above compound. Then, the solvent in which the above compound is dissolved dissolves in the acid chloride or the acid chloride solution, so that a capsule having a smaller particle size can be produced. Furthermore, a capsule having a small particle diameter of 0.0001 mm to 0.01 mm can be produced by spraying the mixture solution with a spray. Although it will not specifically limit if it is a good solvent of the said compound as a solvent soluble in an acid chloride and an acid chloride solution, For example, acetone, 2-butanone, ethyl acetate, etc. are mentioned.

  Further, the above compound may be added while the acid chloride or its solution is heated. The temperature to heat can be made below the boiling point of an acid chloride or its solution. When the temperature is increased, the capsule formation time on the core surface is shortened, so that the shell thickness is reduced and the formation time can be shortened. Therefore, the reaction temperature is appropriately adjusted according to the desired shell thickness and core volume.

  Moreover, you may throw in the said compound in the state which cooled the acid chloride or its solution. The cooling temperature can be higher than the freezing point of the acid chloride or its solution. When the temperature is lowered, the capsule formation time on the core surface becomes longer and the shell thickness can be increased. The reaction temperature is appropriately adjusted according to the desired shell thickness and core volume.

  When the acid chloride is used in a solution state, the solvent is not limited as long as it is a good solvent for acid chloride, but is preferably a poor solvent for the core substance. In the case of the poor solvent for the core material, the core does not elute into the solution after the core is dropped, so that stable core formation is possible. As such a good solvent, an aliphatic alkane is preferable, and examples thereof include N-hexane, N-heptane, N-nonane, N-decane, and N-dodecane.

  The poor solvent is appropriately selected according to the material of the core part, but aliphatic hydrocarbon solvents such as hexane, heptane, octane, nonane, decane, and dodecane are poor solvents for many of the above compounds, and should be used preferably. it can.

  Further, a thick shell is formed in a short time when the acid chloride concentration of the acid chloride solution is high, but it is possible to adjust the thickness of the shell by reducing the concentration. Since the reaction between the acid chloride and the core substance proceeds quantitatively, the shell can be formed even if the concentration of the acid chloride is low even if the concentration is low, but the shell is formed when the concentration is 0.1% by volume or less. The amount and volume of the solution becomes too large to make the amount of acid chloride necessary for the solution, making it economically unsuitable.

  The core-shell type capsule of the present embodiment includes a dissolution step in which the above compound is dissolved in a poor solvent until the solubility is saturated, and a crystallization step in which the obtained solution is cooled to crystallize the compound. And a dropping step of forming a shell portion by dropping acid chloride into the obtained mixture.

  Further, by pulverizing the crystal after crystallization and then dropping the acid chloride or the acid chloride solution, a microcapsule having a smaller particle diameter can be produced.

  In addition, microcapsules having a small particle size with a uniform particle size distribution with fine particles as nuclei can be prepared by dispersing and stirring fine particles of 10 μm or less in a heated poor solvent saturated solution of the mixture while stirring.

  It is preferable that the particle size of the fine particles is as small as possible to be a precipitation nucleus of the mixture because the properties of the microcapsules are not affected. Generally, if there is a particle size of 100 nm or more, it can be a precipitation nucleus.

  The material of the fine particles is not particularly limited as long as the mixture can be recrystallized uniformly. For example, silica fine particles, styrene fine particles, polyimide fine particles, MBS fine particles and the like can be used, but are not limited thereto.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to this.

Example 1
Adipoyl chloride (manufactured by Kanto Chemical Co., Ltd .: special grade) is used as the acid chloride, and hexamethylenediamine (manufactured by Kanto Chemical Co., Ltd .: special grade) is used as the compound having two or more functional groups capable of nucleophilic reaction with acid chloride in the molecule. Got ready.
10 drops of adipoyl chloride weighed in a beaker, 10 drops of liquefied hexamethylene diamine heated to 50 ° C. and melted with a dropper (As One Polydropper), and the surface of the dropped hexamethylene diamine reacts with adipoyl chloride. Ten microcapsules 1 were produced.
The obtained ten microcapsules 1 were observed with a metallographic microscope to determine the average particle size. The results are shown in Table 1. In addition, the diameter of each particle | grain was calculated | required as an average value of a major axis and a minor axis, when not spherical.
When one microcapsule obtained was observed with a CT scan (Shimadzu Corporation, inspexio SMX-90CT), a shell (shell part) of about 100 μm was formed on the capsule surface as shown in FIG. Confirmed that. In FIG. 1, the substantially circular white part is a 6,6-nylon shell which is a reaction product of adipoyl chloride and hexamethylene diamine, and the black part inside thereof is unreacted hexamethylene encapsulated in the shell. Diamine.
The obtained microcapsule 1 was put into a bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd .: trade name jER828), stirred for 30 seconds, and then observed for 1 day at room temperature. The gel time at 200 ° C. of the microcapsule / bisphenol A type epoxy resin mixture after standing at room temperature for 1 day was measured. The results are shown in Table 1.
In addition, about the microcapsules 2-11 obtained in Examples 2-11, the property after leaving to 1 at room temperature was observed similarly, and the gel time was measured after that. The results are shown in Table 1.

(Example 2)
Microcapsule 2 as in Example 1 except that liquefied p-phenylenediamine heated to 150 ° C. and melted was used as a compound having two or more functional groups that nucleophilically react with acid chloride in the molecule. Got.

(Example 3)
1,4 benzenedithiol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) powder (average particle diameter observed with a metallurgical microscope) pulverized in an agate mortar as a compound having two or more functional groups that nucleophilically react with acid chloride in the molecule A microcapsule 3 was obtained in the same manner as in Example 1 except that about 100 μm) was used.

Example 4
A microcapsule 4 was obtained in the same manner as in Example 1 except that the adipoyl chloride used was a 5% by volume dodecane (made by Wako Pure Chemical Industries, Ltd .: special grade) solution.

(Example 5)
A microcapsule 5 was obtained in the same manner as in Example 1 except that the adipoyl chloride used was changed to a 1% by volume dodecane solution.

(Example 6)
The microcapsule 6 was prepared in the same manner as in Example 1 except that a solution of 5% by volume of a mixture of trimellitic acid chloride (ISOCHEM France) and adipoyl chloride in a mass ratio of 1: 9 dissolved in dodecane was used as the acid chloride. Obtained.

(Example 7)
A microcapsule 7 was prepared in the same manner as in Example 1 except that 30% by volume of silica spheres having an average particle size of 0.1 mm (Fuji Silysia Co., Ltd .: product name; Chromatrex) were used in liquid hexamethylenediamine Obtained.

(Example 8)
A microcapsule 8 was obtained in the same manner as in Example 1 except that 70% by volume of silica spheres having an average particle diameter of 0.1 mm was used in liquid hexamethylenediamine.

Example 9
A microcapsule 9 was obtained in the same manner as in Example 1 except that liquid hexamethylenediamine was sprayed onto adipoyl chloride with a spray (organic solvent spray as one) instead of dropping with a dropper.
Moreover, when the obtained microcapsule 9 was used for differential thermal / thermogravimetric measurement (TG-DTA; Rigaku Corporation, TG8120), a weight reduction accompanied with endotherm was observed. Table 1 shows the weight reduction start temperature.

(Example 10)
A microcapsule 10 was obtained in the same manner as in Example 4 except that a solution of 20% by weight of hexamethylenediamine dissolved in ethyl acetate was used instead of liquid hexamethylenediamine.
Moreover, when the differential heat | fever thermogravimetry was performed using the obtained microcapsule 10, the weight reduction accompanying heat absorption was observed. Table 1 shows the weight reduction start temperature.

(Example 11)
1 g of a solution of 20% by weight of hexamethylenediamine dissolved in ethyl acetate was added dropwise to 10 g of dodecane to crystallize hexamethylenediamine. To the resulting mixture, 10 g of a solution of 5% by weight of adipoyl chloride dissolved in dodecane was added dropwise to obtain microcapsules 11.
Further, when differential heat / thermogravimetric measurement was performed using the obtained microcapsule 11, a weight decrease accompanied with endotherm was observed. Table 1 shows the weight reduction start temperature.

(Comparative Example 1)
Table 1 shows the weight decrease starting temperature at which the differential heat and thermogravimetric measurement of hexamethylenediamine was performed.
The liquefied hexamethylenediamine heated to 50 ° C. and melted was directly added dropwise to the bisphenol A type epoxy resin, stirred for 30 seconds, and allowed to stand at room temperature for 1 day to solidify.

(Comparative Example 2)
Table 1 shows the weight decrease starting temperature at which differential thermal and thermogravimetric measurements of 1,4 benzenedithiol were performed.
The 1,4 benzenedithiol powder produced in the same manner as in Example 3 was directly added dropwise to the bisphenol A type epoxy resin, stirred for 30 seconds, and allowed to stand at room temperature for 1 day to solidify.

(Comparative Example 3)
Although it processed like Example 3 except having used succinic acid (made by Tokyo Chemical Industry Co., Ltd.) which does not nucleophilic-react with an acid chloride instead of 1,4 benzenedithiol, the microcapsule was not obtained.

(Comparative Example 4)
Although it processed like Example 1 except having used n-dodecylamine (made by Tokyo Chemical Industry Co., Ltd.) instead of hexamethylenediamine, a microcapsule was not obtained.

(Comparative Example 5)
A microcapsule 12 was obtained in the same manner as in Example 1 except that hexanoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the acid chloride.
The liquefied hexamethylenediamine heated to 50 ° C. and melted was directly added dropwise to the bisphenol A type epoxy resin, stirred for 30 seconds, and allowed to stand at room temperature for 1 day to solidify.

Claims (2)

A core portion containing a thiol compound having two or more thiol groups in the molecule;
A shell portion containing a polymer obtained by reacting the thiol compound and a bifunctional or higher acid chloride;
A core-shell type capsule for epoxy resin curing agent, formed from A core portion containing an amine compound having two or more amine groups in the molecule;
A shell portion containing a polyamide resin obtained by reacting the amine compound with a bifunctional or higher acid chloride;
A core-shell type capsule for epoxy resin curing agent, formed from