JP6024667B2 - Ink composition - Google Patents

Description

  The present invention relates to an ink composition that is decolored or discolored by applying the color developing performance and decoloring performance of a leuco dye.

2. Description of the Related Art Conventionally, heat-sensitive decolorizable ink compositions using the leuco dye developing and decoloring performances are known.
This is made up of a leuco dye as an electron donor, a developer as an electron acceptor, and a decoloring agent, and utilizes color development and decoloring by their interaction. Color develops when the developer acts on the leuco dye.
In Patent Document 1, a dissolution medium that melts by heat such as rubbing to dissolve a leuco dye or a developer is used as a decolorizer, and the decolorizer is encapsulated in a capsule together with the leuco dye and the developer. An erasable ink for use as a pigment is disclosed. In this decolorizable ink, when friction is applied to the handwriting and heat is applied to the microcapsule pigment, the decolorizer melts and dissolves the leuco dye or developer, and the dissolution medium becomes the developer. By acting, the color developing effect of the developer on the leuco dye is lost, and the handwriting is in a decolored state.
Patent Document 1 discloses that the melting point width (thermal hysteresis) is adjusted by setting the freezing point of the solution of the decoloring agent and the developer in the dissolved state at the time of decoloring to be relatively low, and heat generated by rubbing ( It is also described that the temperature at which the handwritten color erased at 64 ° C. is recolored is set to a temperature of −18 ° C. or lower and the color is not regenerated in a temperature environment higher than that.

Japanese Unexamined Patent Publication No. 2008-280440

The erasable ink composition described in Patent Document 1 controls the color development and color erasure state by the thermal hysteresis width of the color erasing agent that is a dissolution medium of the leuco dye and the developer. In order to have thermal hysteresis, a carboxylic acid containing an unsubstituted aromatic ring having a high molecular weight and an ester of an aliphatic alcohol having 10 or more carbon atoms, an odd aliphatic monohydric alcohol having 9 or more carbon atoms and a carbon number are used. It is necessary to use aliphatic esters obtained from even-numbered aliphatic carboxylic acids. Generally, as the molecular weight of the solvent increases, the dissolution performance tends to decrease, and a large amount of solvent is required to dissolve the developer.
Specifically, diphenylmethane phthalides, phenyl indolyl phthalides, and the like are used, and a preferable ratio of the constituent components is leuco dye: developer: dissolution medium = 1: 0.5 to 20: 5. The above performance is achieved by setting the ratio to 200. As a result, the leuco dye concentration cannot be relatively increased, and the ink has to have a small proportion of coloring components. Furthermore, since the color of the leuco dye can be seen through the microcapsule film because it is a microcapsule pigment, the color development as a microcapsule pigment becomes weak and the handwriting is inevitably thinned.

The present invention relates to a microcapsule that contains at least a liquid material of a substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group, a leuco dye, and a developer. And an erasable ink composition containing at least an ink liquid medium.
The second gist is an erasable ink composition having a boiling point of 250 ° C. or higher.
A third gist is an erasable ink composition in which the liquid is a solid solution having one or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group. .
A fourth gist is an erasable ink composition in which a solid having one or more functional groups selected from the ester group, ketone group, ether group and aliphatic hydroxyl group is amorphous.
A erasable ink composition having an average particle diameter of 1 to 10 μm of the microcapsules is a fifth gist.

The handwriting written with the erasable ink composition of the present invention, when a force greater than the strength of the microcapsule is applied, the microcapsule is destroyed, and the ester group, ketone group, ether group, A liquid material having at least one or two or more functional groups selected from aliphatic hydroxyl groups exudes. Each of the ester group, ketone group, ether group and aliphatic hydroxyl group has an oxygen atom with an increased electron density, and attracts H ⁺ having electron vacancies from the developer. As a result, the electron acceptor effect of the developer is lost, and the lactone ring, pyridine ring, quinazoline ring, bisquinazoline ring, etc. of the leuco dye are closed and decolored.
In the ink composition of the present invention, the decolorizing liquid is encapsulated in a microcapsule and separated from the leuco dye or developer, so that the leuco dye and the developer are directly dissolved in the ink liquid medium, or the leuco dye. Since the developer obtained by pigmentizing the developer can be dispersed in the liquid medium, the coloring component can be blended at a high concentration, and a handwriting with good color can be formed.

  In addition, when the boiling point of the liquid substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group included in the microcapsule is 250 ° C. or higher, immediately Since it does not volatilize and remains on the handwriting, it continues to act on the developer and the decolored state is maintained.

In addition, a liquid substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group included in the microcapsule is an ester group, a ketone group, an ether group, a fatty acid. In the case of a solid solution having one or more functional groups selected from an aromatic group, when the solid solvent evaporates, the solvent is selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group. Since the solid having one or more functional groups is solidified while maintaining the state attracting H ⁺ from the developer at the molecular level, it is difficult to recolor, and the decolored state is reliably maintained. .

At this time, when the solid having one or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group is crystalline, the arrangement of atoms and molecules is regular and dissolved. When it solidifies again, it returns to a regular arrangement, but when a mixture of impurities such as H ⁺ is solidified, it does not take a regular arrangement and becomes amorphous and solidifies while attracting H ^+. Therefore, it is assumed that the decolored state is maintained. However, some release H ⁺ and return to a regular array. When this solid is amorphous, the arrangement of atoms and molecules is not regular, and H ⁺ that is bound at the time of dissolution is solidified while confined in the molecule, so that H ⁺ is not released again and more reliably. The decolored state is maintained.

  In addition, by setting the average particle diameter of the microcapsules to 1 to 10 μm, the microcapsules can be embedded in paper fibers or destroyed with an appropriate force to release the inclusions. Handwriting that cannot be erased by writing pressure can be formed.

The erasable ink composition of the present invention acts and develops color when both the leuco dye as the electron donor and the developer as the electron acceptor are in a dissolved state.
For decoloring, it is necessary to attract H ⁺ from the developer to a liquid material having at least one or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group. For this purpose, both the developer and the substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group must act in a solution state. Therefore, the liquid medium of the ink composition is either selected from those that dissolve the developer or the liquid encapsulated in the microcapsules, that is, an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group. Organic solvent having at least one or two or more functional groups, or one or more selected from ester groups, ketone groups, ether groups and aliphatic hydroxyl groups A liquid that dissolves a solid having at least one functional group, or a solid solution having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group, or a microcapsule It is necessary to employ a liquid that dissolves the developer in any of the other liquids that can be encapsulated.

A microcapsule is obtained by emulsifying a core material (liquid contained in a microcapsule) with a homogenizer, a high-pressure homogenizer, a magnetic stirrer, etc., and then forming a film using a magnetic stirrer or a three-one motor. Many are substantially spherical, but may be disk-shaped or irregularly shaped.
A conventionally known emulsifier can be used for emulsification of the core substance. Specifically, as a nonionic emulsifier, propylene glycol fatty acid ester, glycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene alkylphenyl Examples include fatty acid ester, polyoxyethylene castor oil, polyoxyethylene sterol, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, and polyvinyl alcohol. Examples of the anionic emulsifier include polyoxyethylene alkyl ether phosphate, sorbitan monolaurate, sorbitan monolaurate polyoxyethylene ether, acrylic resin, styrene maleic acid resin, and isobutylene maleic anhydride resin. Examples of the cationic emulsifier include polyoxyethylene alkylamine and polyoxyethylene fatty acid amide. In addition, when using the melamine resin and urea resin mentioned later as a material which forms the outline of a microcapsule, emulsifiers, such as an acrylic resin and styrene-maleic acid resin which have at least a carboxyl group, are used. This is because melamine or urea methylated on the surface of the decolored liquid that has become oil droplets forms a microcapsule film by an acid amide bond to the carboxyl group of the emulsifier.
Examples of the material forming the outline of the microcapsule include urethane resin, melamine resin, urea resin, epoxy resin, phenol resin, unsaturated polyester resin as thermosetting resin, and polyimide, polyamide and the like as thermoplastic resin. The thermosetting resin has a property of being hard but brittle. When a force exceeding the strength of the microcapsules is applied, the thermosetting resin can be immediately broken and the inclusions can be released, so that the handwriting can be erased reliably.
Since the portion to be erased of the handwriting is used by applying force with an erasing tool to destroy the microcapsule, the average particle diameter of the microcapsule is preferably 1 to 10 μm. This is because if it is less than 1 μm, the microcapsule is buried in the fiber of the paper, making it difficult to destroy at the time of erasing, and if it exceeds 10 μm, it is broken just by rubbing the mark with a finger and the handwriting is erased. This is because there are concerns.
In addition, when microcapsules produced in water are used for oil-based ballpoint pens containing benzyl alcohol or ethylene glycol monophenyl ether as a main solvent, the microcapsules must be dried and dispersed in these solvents. At that time, polyvinyl pyrrolidone or glycerin can be obtained by adding a high boiling point solvent such as polyvinyl pyrrolidone (PVP) or glycerin that is soluble in both water and an ink solvent such as benzyl alcohol or phenyl glycol to the microcapsule dispersion and drying it. Coated microcapsules are made. This is preferable because the dried microcapsule mass can be loosened with a solvent such as benzyl alcohol or ethylene glycol monophenyl ether with a weak force, and even a microcapsule with a low film strength can be dispersed in the ink without breaking.
Further, when the erasable ink composition of the present invention is used in a ballpoint pen, the average particle diameter is 1 to 10 μm, and 10 particles of the total number of microcapsules in which particles having a particle diameter of 15 μm or more are blended in the ink composition. It is preferable that it is less than number%. This has a gap of several tens of microns in the passage of the ink composition in the ballpoint pen and can be sufficiently discharged. Also, paper fibers have irregularities of several microns to 10 microns, and the microcapsules enter here when writing, so even if a force such as writing pressure is applied during writing, the microcapsules are difficult to break and are destroyed. Hateful. However, there is a concern that particles of 15 μm or more are broken between paper and a ball-point pen ball at the time of writing and the handwriting becomes thin.

One or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group that act as an erasing agent for a colorant developed with a leuco dye and a developer. The liquid substance having at least the above refers to a liquid having these functional groups in the structure, a solid solution having these functional groups, or a mixture of both. In addition, liquid other than the liquid having the functional group in the structure, other solutes, solids, etc. may be present in the microcapsules.
If the boiling point of the liquid substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group is 250 ° C. or higher, it will not volatilize immediately on the handwriting. Therefore, it can be said that the decolored state continues to act on the developer and is preferable, but for that purpose, one or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group are used. In addition to the case where the boiling point of the liquid itself has a boiling point of 250 ° C. or higher, dissolution of a solid in which the liquid material has one or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group In the case of a liquid, the boiling point of the solution may be 250 ° C. or higher, or the boiling point of the solvent of the solution may be 250 ° C. or higher.
A specific example of a liquid having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group encapsulated in a microcapsule is ethyl benzoate ( Boiling point 213.2 ° C., viscosity 2.0 mPa · s), benzyl acetate (boiling point 215.5 ° C., viscosity 1.4 mPa · s), dibutyl oxalate (boiling point 240 ° C., viscosity 3.4 mPa · s), isoamyl propionate (Boiling point 160.7 ° C., viscosity 1.4 mPa · s), butyl propionate (boiling point 146.8 ° C., viscosity 0.7 mPa · s), methyl propionate (boiling point 79.8 ° C., viscosity 0.5 mPa · s) Methyl acetoacetate (boiling point 171 ° C., viscosity 1.7 mPa · s), ethyl formate (boiling point 53 ° C., viscosity 0.4 mPa · s), butyl formate (boiling point 106.8) , Viscosity 0.7 mPa · s), propyl formate (boiling point 81 ° C., viscosity 0.5 mPa · s), amyl acetate (boiling point 149.2 ° C., viscosity 0.9 mPa · s), isoamyl acetate (boiling point 142.1 ° C., (Viscosity 0.9 mPa · s), isobutyl acetate (boiling point 116.6 ° C., viscosity 0.7 mPa · s), isopropyl acetate (boiling point 88.6 ° C., viscosity 0.6 mPa · s), 2-ethylhexyl acetate (boiling point 198. 6 ° C., viscosity 1.5 mPa · s), cyclohexyl acetate (viscosity 0.9 mPa · s), n-butyl acetate (viscosity 0.7 mPa · s), s-butyl acetate (boiling point 177 ° C., viscosity 0.7 mPa · s) ), Methyl cyclohexyl acetate (boiling point 181.5 ° C., viscosity 2.3 mPa · s), ethyl butyrate (boiling point 121.4 ° C., viscosity 0.6 mPa · s), diethyl adipate (boiling point 251 ° C., 3.6 mPa · s), dioctyl adipate (boiling point 214 ° C. (5 mmHg), viscosity 1.2 mPa · s), triethyl acetylcitrate (boiling point 131 ° C. (1 mmHg), viscosity 53.7 mPa · s), acetylcitric acid Tributyl (boiling point 172 ° C. (1 mmHg), viscosity 42.7 mPa · s), methyl abietic acid (boiling point 360 ° C., viscosity 3.4 mPa · s), benzyl benzoate (boiling point 323 ° C., viscosity 9.7 mPa · s), silica Ethyl cinnamate (boiling point 271 ° C., viscosity 8.7 mPa · s), diethyl tartrate (boiling point 280 ° C.), dibutyl tartrate (boiling point 128 ° C. (12 mmHg), viscosity 10.6 mPa · s), amyl stearate (boiling point 192 ° C. ( 2 mmHg)), ethyl stearate (boiling point 199 ° C. (10 mmHg)), butyl stearate (boiling point 343 ° C. , Viscosity 8.3 mPa · s), bis (2-ethylhexyl) sebacate (boiling point 312 ° C., viscosity 19.9 mPa · s), diethyl phthalate (boiling point 296.1 ° C., viscosity 10.0 mPa · s), phthalic acid Dioctyl (boiling point 361 ° C., viscosity 81.4 mPa · s), dibutyl phthalate (boiling point 340.7 ° C., viscosity 20.0 mPa · s), diisononyl phthalate (boiling point 296.1 ° C., viscosity 78.0 mPa · s), Examples thereof include dimethyl phthalate (boiling point 282 ° C., viscosity 17.2 mPa · s) and dibutyl maleate (boiling point 280.6 ° C., viscosity 4.7 mPa · s).
As liquids having an ether group, 1,2-epoxybutane (boiling point 63 ° C., viscosity 0.4 mPa · s), diisopropyl ether (boiling point 68.5 ° C., viscosity 0.3 mPa · s), diethyl ether (boiling point 34.6). ° C, viscosity 0.2 mPa · s), dibutyl ether (boiling point 142 ° C, viscosity 0.7 mPa · s), vinyl ethyl ether (boiling point 35.8 ° C, viscosity 0.2 mPa · s), phenetole (boiling point 170.3 ° C) , Viscosity 1.1 mPa · s), diphenyl ether (boiling point 259 ° C., viscosity 3.7 mPa · s), and the like.
As a liquid having a ketone group, acetophenone (boiling point 201.7 ° C., viscosity 1.6 mPa · s), methyl-n-butyl ketone (boiling point 127 ° C., viscosity 0.63 mPa · s), diisobutyl ketone (boiling point 163 ° C., viscosity 0) .9 mPa · s), diisopropyl ketone (boiling point 124.4 ° C., viscosity 0.6 mPa · s), di-n-propyl ketone (boiling point 143.7 ° C., viscosity 0.7 mPa · s), methyl-n-amyl ketone ( Boiling point 151.5 ° C., viscosity 0.8 mPa · s), methyl isobutyl ketone (boiling point 116.2 ° C., viscosity 0.5 mPa · s), methylcyclohexanone (boiling point 169 ° C., viscosity 1.8 mPa · s), methyl-n -Hexyl ketone (boiling point 172.9 ° C.), methyl-n-heptyl ketone (boiling point 195.3 ° C.) and the like.
As a liquid having an aliphatic hydroxyl group, undecanol (boiling point 243 ° C., viscosity 17.2 mPa · s), 2-octanol (boiling point 178 ° C., viscosity 8.2 mPa · s), n-decanol (boiling point 231 ° C., viscosity 1.38 mPa) S), α-terpioneel (boiling point 219 ° C.), 1-nonanol (boiling point 214 ° C., viscosity 14.3 mPa · s), ethylene glycol monohexyl ether (boiling point 208.3 ° C., viscosity 5.2 mPa · s), 1,3-octylene glycol (boiling point: 244.2 ° C., viscosity: 323 mPa · s), 2-ethylbutanol (boiling point: 147 ° C., viscosity: 5.6 mPa · s), 2-ethylhexanol (boiling point: 184.7 ° C., viscosity: 9) .8 mPa · s), n-octanol (boiling point 195 ° C., viscosity 8.2 mPa · s), fusel oil (boiling point 110 to 130 ° C.), n Hexanol (boiling point 157.1 ° C., viscosity 5.2 mPa · s), 2-heptanol (boiling point 160.4 ° C., viscosity 6.5 mPa · s), 3-heptanol (boiling point 156.4 ° C., viscosity 7.1 mPa · s) ), N-heptanol (boiling point: 176.3 ° C., viscosity: 7.0 mPa · s), 2-methylcyclohexanol (boiling point: 167.6 ° C.), and the like. These can also be mixed and used.
In addition, the thing without an atmospheric pressure display in the description of a boiling point shows the boiling point in a normal pressure (760 mmHg).

When the liquid substance having at least one or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group is a solid solution having these functional groups, the solid is dissolved in the liquid Use it in the condition. By being in a dissolved state, H ⁺ having electron vacancies from the developer is attracted and decolored, and even after the solvent evaporates and solidifies, H ⁺ is continuously attracted and the decolored state is maintained.
Specifically, as crystalline ones having an ester group, diphenylurethane, N- (tert-butoxycarbonyl) -β-alanine, 1-acetoxy-2-methoxy-4- (1-propenyl) benzene, 3 ′ , 5'-diacetoxyacetophenone, diphenyl phthalate, dicyclohexyl phthalate, methyl 2-benzoylbenzoate, phenyl benzoate, diphenyl carbonate, 2,2-bis (4-acetoxyphenyl) propane, 4-acetoxybiphenyl, phenylacetic acid p-tolyl, methyl diphenylacetate, ethylene glycol dibenzoate, pentaerythritol tetrastearate, trimethyl citrate, 4'-acetoxyacetophenone, 4-methoxyphenylacetic anhydride, methyl 3,4,5-trimethoxybenzoate, salicylic acid 4 -Ok Butylphenyl and the like.
As an amorphous substance having an ester group, cetyl palmitate, glyceryl monomyristate, glyceryl monostearate, glyceryl distearate, polyoxyethylene glyceryl monostearate, diglyceryl monostearate, tetraglyceryl monostearate, tristearic acid Tetraglyceryl, tetraglyceryl pentastearate, hexaglyceryl monostearate, hexaglyceryl tristearate, hexaglyceryl pentastearate, decaglyceryl monostearate, decaglyceryl distearate, decaglyceryl tristearate, decaglyceryl pentastearate, Decastearate decaglyceryl, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquistearate, Nosutearin acid polyethylene glycol, ethylene glycol monostearate, ethylene glycol distearate, diethylene glycol stearate, polyethylene glycol distearate, acrylic resins, alkyd resins, and ester gum and the like.
Crystals having an ether group include 4-methoxy-2-methyldiphenylamine, 3-methoxydiphenylamine, benzoin isopropyl ether, 1,3,5-trimethoxybenzene, 1,4-diethoxybenzene, triphenyl phosphate, 4- And methyl acetoxybenzoate.
As an amorphous substance having an ether group, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene decyl tetradecyl ether, polyoxyethylene lanolin alcohol, polyoxyethylene sorbit beeswax, Examples include xylene resins.
As crystals having a ketone group, N- (2-phenylethyl) acetamide, acetoacetanilide, lidocaine, myristic acid anilide, N-acetyl-o-phenetidine, N-carboethoxyphthalimide, N-carbobenzoxyoxysuccinimide, tetradeca Nophenone, 2′-acetonaphthone, 4-butyrylbiphenyl, 4-methoxybenzophenone, benzophenone, cyclohexylphenylketone, 1,3-diphenyl-1,3-propanedione, benzoin ethyl ether, 2,2-dimethoxy-2- Examples include phenylacetophenone, 4,4′-bicyclohexanone, 4-tert-butylcyclohexanone, 4,4′-bis (methoxymethyl) biphenyl, 12-tricosanone, 6-methoxy-1-tetralone, and the like.
Examples of the amorphous substance having a ketone group include a ketone resin.
Examples of the crystal having an aliphatic hydroxyl group include cetanol, stearyl alcohol, 1-docosanol and the like.
Examples of the amorphous having an aliphatic hydroxyl group include behenyl alcohol.
These solids having one or more functional groups selected from ester groups, ketone groups, ether groups and aliphatic hydroxyl groups can be used alone or in combination. A preferred addition amount is 0.1 to 10% by weight based on the total weight of the developer used in the ink composition. If it is less than 0.1% by weight, the liquid encapsulated in the microcapsule may be recolored after volatilization. Depending on the type, even if it exceeds approximately 10% by weight, a significant improvement in the effect is obtained. I can't.

In order to make these solids act as a color erasing agent, specific examples of liquids for dissolving them include the following.
As the liquid having an ester group, ethyl benzoate (boiling point 213.2 ° C., viscosity 2.0 mPa · s), benzyl acetate (boiling point 215.5 ° C., viscosity 1.4 mPa · s), dibutyl oxalate (boiling point 240 ° C., Viscosity 3.4 mPa · s), isoamyl propionate (boiling point 160.7 ° C., viscosity 1.4 mPa · s), butyl propionate (boiling point 146.8 ° C., viscosity 0.7 mPa · s), methyl propionate (boiling point 79 0.8 ° C., viscosity 0.5 mPa · s), methyl acetoacetate (boiling point 171 ° C., viscosity 1.7 mPa · s), ethyl formate (boiling point 53 ° C., viscosity 0.4 mPa · s), butyl formate (boiling point 106.8) ° C, viscosity 0.7 mPa · s), propyl formate (boiling point 81 ° C, viscosity 0.5 mPa · s), amyl acetate (boiling point 149.2 ° C, viscosity 0.9 mPa · s), isoamyl acetate ( 142.1 ° C, viscosity 0.9 mPa · s), isobutyl acetate (boiling point 116.6 ° C, viscosity 0.7 mPa · s), isopropyl acetate (boiling point 88.6 ° C, viscosity 0.6 mPa · s), acetic acid 2 -Ethylhexyl (boiling point 198.6 ° C., 1.5 mPa · s), cyclohexyl acetate (viscosity 0.9 mPa · s), n-butyl acetate (viscosity 0.7 mPa · s), s-butyl acetate (boiling point 177 ° C., viscosity) 0.7 mPa · s), methyl cyclohexyl acetate (boiling point 181.5 ° C., viscosity 2.3 mPa · s), ethyl butyrate (boiling point 121.4 ° C., viscosity 0.6 mPa · s), diethyl adipate (boiling point 251 ° C., Viscosity 3.6 mPa · s), Dioctyl adipate (boiling point 214 ° C. (5 mmHg), viscosity 1.2 mPa · s), triethyl acetyl citrate (boiling point 131 ° C. (1 mmHg)) Viscosity 53.7 mPa · s), tributyl acetylcitrate (boiling point 172 ° C. (1 mmHg), viscosity 42.7 mPa · s), methyl abietic acid (boiling point 360 ° C., viscosity 3.4 mPa · s), benzyl benzoate (boiling point 323) ° C, viscosity 9.7 mPa · s), ethyl cinnamate (boiling point 271 ° C, viscosity 8.7 mPa · s), diethyl tartrate (boiling point 280 ° C), dibutyl tartrate (boiling point 128 ° C (12 mmHg), viscosity 10.6 mPa · s) s), amyl stearate (boiling point 192 ° C. (2 mmHg)), ethyl stearate (boiling point 199 ° C. (10 mmHg)), butyl stearate (boiling point 343 ° C., viscosity 8.3 mPa · s), bis (2-ethylhexyl) sebacate ) (Boiling point 312 ° C., viscosity 19.9 mPa · s), diethyl phthalate (boiling point 296.1 ° C., viscosity 10.0) mPa · s), dioctyl phthalate (boiling point 361 ° C., viscosity 81.4 mPa · s), dibutyl phthalate (boiling point 340.7 ° C., viscosity 20.0 mPa · s), diisononyl phthalate (boiling point 296.1 ° C., viscosity) 78.0 mPa · s), dimethyl phthalate (boiling point 282 ° C., viscosity 17.2 mPa · s), dibutyl maleate (boiling point 280.6 ° C., viscosity 4.7 mPa · s), and the like.
As liquids having an ether group, 1,2-epoxybutane (boiling point 63 ° C., viscosity 0.4 mPa · s), diisopropyl ether (boiling point 68.5 ° C., viscosity 0.3 mPa · s), diethyl ether (boiling point 34.6). ° C, viscosity 0.2 mPa · s), dibutyl ether (boiling point 142 ° C, viscosity 0.7 mPa · s), vinyl ethyl ether (boiling point 35.8 ° C, viscosity 0.2 mPa · s), phenetole (boiling point 170.3 ° C) , Viscosity 1.1 mPa · s), diphenyl ether (boiling point 259 ° C., viscosity 3.7 mPa · s), and the like.
As a liquid having a ketone group, acetophenone (boiling point 201.7 ° C., viscosity 1.6 mPa · s), methyl-n-butyl ketone (boiling points 127 ° C., 0.63 mPa · s), diisobutyl ketone (boiling point 163 ° C., viscosity 0. 9 mPa · s), diisopropyl ketone (boiling point 124.4 ° C., viscosity 0.6 mPa · s), di-n-propyl ketone (boiling point 143.7 ° C., viscosity 0.7 mPa · s), methyl-n-amyl ketone (boiling point) 151.5 ° C., viscosity 0.8 mPa · s), methyl isobutyl ketone (boiling point 116.2 ° C., 0.5 mPa · s), methylcyclohexanone (boiling point 169 ° C., viscosity 1.8 mPa · s), methyl-n-hexyl Examples include ketones (boiling point 172.9 ° C.) and methyl-n-heptyl ketone (boiling point 195.3 ° C.).
As a liquid having an aliphatic hydroxyl group, undecanol (boiling point 243 ° C., viscosity 17.2 mPa · s), 2-octanol (boiling point 178 ° C., viscosity 8.2 mPa · s), n-decanol (boiling point 231 ° C., viscosity 1.38 mPa) S), α-terpioneel (boiling point 219 ° C.), 1-nonanol (boiling point 214 ° C., viscosity 14.3 mPa · s), ethylene glycol monohexyl ether (boiling point 208.3 ° C., viscosity 5.2 mPa · s), 1,3-octylene glycol (boiling point: 244.2 ° C., viscosity: 323 mPa · s), 2-ethylbutanol (boiling point: 147 ° C., viscosity: 5.6 mPa · s), 2-ethylhexanol (boiling point: 184.7 ° C., viscosity: 9) .8 mPa · s), n-octanol (boiling point 195 ° C., viscosity 8.2 mPa · s), fusel oil (boiling point 110 to 130 ° C.), n Hexanol (boiling point 157.1 ° C., viscosity 5.2 mPa · s), 2-heptanol (boiling point 160.4 ° C., viscosity 6.5 mPa · s), 3-heptanol (boiling point 156.4 ° C., viscosity 7.1 mPa · s) ), N-heptanol (boiling point: 176.3 ° C., viscosity: 7.0 mPa · s), 2-methylcyclohexanol (boiling point: 167.6 ° C.), and the like.
As hydrocarbon liquids, amylbenzene (boiling point 202 ° C), isopropylbenzene (boiling point 152 ° C), ethylbenzene (boiling point 136 ° C), octane (boiling point 125 ° C), xylene (boiling point 138 to 144 ° C), 1,2- Ethylbenzene (boiling point 183 ° C), cyclohexylbenzene (boiling point 239 ° C), dipentene (boiling point 177 ° C), dimethylnaphthalene (boiling point 262.1-286.6 ° C), p-cymene (boiling point 177 ° C), decane (boiling point 174 ° C) ), Tetralin (boiling point 207 ° C), dodecylbenzene (boiling point 270-331 ° C), naphthalene (boiling point 218 ° C), heptane (boiling point 98.4 ° C), methylcyclohexane (boiling point 101 ° C), liquid paraffin (boiling point 300 ° C or higher) ) And the like.
These can also be mixed and used.
In addition, the thing without an atmospheric pressure display in the description of a boiling point shows the boiling point in a normal pressure (760 mmHg).

A leuco dye is an electron-donating dye that reacts with a developer that is an electron acceptor, that is, develops color by opening a lactone ring or the like and taking a resonance structure by H ⁺ having electron vacancies. is there. Examples of leuco dyes include diphenylmethane phthalide dyes, fluorane dyes, indolyl phthalide dyes, spiropyran dyes, rhodamine lactam dyes, azaphthalide dyes, and the like. Specific examples are given below, but the present invention is not limited to these.
For example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 2'-anilo-6-6- (N-ethyl-N-isopentylamino) -3'-methylspiro [phthalide-3 , 9 ′-(9H) xanthene] -3-one, 2′-methyl-6 ′-(Np-tolyl-Nethylamino) spiro [isobenzofuran-1 (3H), 9 ′-(9H) xanthene ] -3-one, 2-methyl-6- (N-ethyl-Np-tolylamino) fluorane, 3,3-bis (1-n-butyl-2-methylindol-3-yl) phthalide, 3- (4-Diethylamino-2-methylphenyl) -3- (1-ethyl-1H-indol-3-yl) -4-azaphthalide, 9- (diethylamino) spiro [12H-benzo (a) xanthene-12,1 ′ (3'H)- Sobenzofuran] -3′-one, 2-methyl-6- (N-ethyl-Np-tolylamino) fluorane, 5-amino-3 ′, 6′-dihydroxyspiro [isobenzofuran-1 (3H), 9 '-(9H) xanthen] -3-one, 6'-(diethylamino) -1 ', 2'-benzofluorane, 6-amino-3', 6'-dihydroxyspiro [isobenzofuran-1 (3H), 9 ′-(9H) xanthen] -3-one, 3 ′, 6′-bis (diethylamino) -2- (4-nitrophenyl) spiro [isoindole-1,9′-xanthene] -3-one, 2 '-Anilino-6'-dibutylamino-3'-methylspiro [phthalide-3,9'-(9H) xanthen] -3-one, 2 '-(phenylamino) -3-methyl-6- [ethyl (p -Tolyl) amine] spiro [9H Xanthene] -9one, 1 '-[3'H-isobenzofuran] -3-one, 6- (diethylamine) -2- [3- (trifluoromethyl) anilino] spiro [9H-xanthene-9,3' (1′H) -Isobenzofuran] -1′-one, 3,3-bis [2- (4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethenyl] 4,5,6,7-tetra Chloroisobenzofuran-1 (3H) -one, 2 ′-(N-phenyl-N-methylamine) -6 ′, 6 (Np-tolyl-N-ethylamino) spiro [isobenzofuran-1 (3H) ] -3-one, 6-nitro-3 ′, 6′-dihydroxyspiro [isobenzofuran-1 (3H), 9 ′-(9H) xanthen] -3-one, 3-methoxy-4-dedecoxyst Such as linoquinoline. It may be used alone or in combination.
The amount of leuco dye added to the total amount of the ink composition is preferably 1 to 30% by weight. If it is less than 1% by weight, the handwriting density is thin, and if it exceeds 30% by weight, there is a concern that the viscosity of the ink composition is increased and the dischargeability is lowered.
The leuco dye does not need to be dissolved in a liquid substance having at least one or more functional groups selected from an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group.

The developer develops the aforementioned leuco dye, and develops color by acting in a state where the developer and leuco dye are dissolved.
Specific examples of the developer that can be used include inorganic compounds having a substitutable hydrogen and compounds having a phenolic hydroxyl group.
An inorganic compound having a substitutable hydrogen is chemically acidic, releases H ⁺ , and develops a leuco dye. Examples of the inorganic compound having substitutable hydrogen include acidic clay, activated clay montmorillonite, hydrotalcite, hydroxyapatite, phlorizin, aluminum silicate, magnesium silicate, zeolitic acid, magnesium sulfate, and calcium sulfate.
The phenolic hydroxyl group has a low electron density of the oxygen atom of the hydroxyl group due to the I effect of the benzene ring, and as a result, the hydrogen atom is easily released as the active proton H ⁺ . This opens the lactone ring of the leuco dye and develops color.
Specific examples of the compound having a phenolic hydroxyl group include tertiary butylcatechol, n-stearylphenol, o-phenylphenol, hexafluorobisphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, and gallic acid. Acid dodecyl, 2,2-bis (4-hydroxyphenyl) propane, 4,4'-dihydroxydiphenylsulfone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3- Methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -3-methylbutane, 1,1 -Bis (4-hydroxyphenyl) -2-methylpropane, 1, 1-bis (4-hydroxyphenyl) n-hexane, 1,1-bis (4-hydroxyphenyl) n-heptane, 1,1-bis (4-hydroxyphenyl) n-octane, 1,1-bis (4 -Hydroxyphenyl) n-nonane, 1,1-bis (4-hydroxyphenyl) n-decane, 1,1-bis (4-hydroxyphenyl) n-dodecane, 2,2-bis (4-hydroxyphenyl) butane 2,2-bis (4-hydroxyphenyl) ethyl propionate, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2, , 2-bis (4-hydroxyphenyl) n-heptane, 2,2-bis (4′-hydroxyphenyl) n-nonane, novolac type phenol resin, etc. Can be mentioned.
These developers can be used alone or in combination of two or more, and the amount used varies depending on the type, but is generally preferably 1 to 10 relative to leuco dye 1.

In addition, when the leuco dye and the developer are not dissolved in the ink liquid medium to be used, the leuco dye and the developer are dissolved in acetone, methyl ethyl ketone, etc. in advance and dried, pulverized, and pigmented. Use things.
The average particle diameter is preferably 10 μm or less in consideration of dischargeability from the ballpoint pen tip. A preferable addition amount is 2 to 30% by weight.

The ink liquid medium used in the present invention is an aromatic alcohol, ester group, or ketone in which the I effect is blocked by (CH ₂ ) _n between the benzene ring and the hydroxyl group, which is difficult to erase the leuco dye developed by the developer. A hydrocarbon solvent and / or water having no group, ether group or hydroxyl group is used. Specific examples of the aromatic alcohol include benzyl alcohol, phenethyl alcohol, 3-phenyl-1-propanol, 4-phenyl-2-butanol, and specific examples of the aromatic glycol ether include ethylene glycol monophenyl ether and diethylene glycol monophenyl ether. Specific examples of propylene glycol monophenyl ether, ethylene glycol monobenzyl ether, hydrocarbon solvents include aliphatic hydrocarbon solvents such as normal pentane, cyclopentane, methylcyclopentane, normal hexane, isohexane, normal heptane, normal octane, In addition to cyclohexane, methylcyclohexane, ethylcyclohexane, decane, dodecane, etc., Exol DSP 100/140 (above, manufactured by Exxon Chemical Co., Ltd.), etc. And a mixture of these aliphatic hydrocarbon solvents. The amount used is preferably 40 to 70% by weight.

In addition, since it is formed with an ink composition for writing instruments, shear thinning imparting agent, dye compound, resin dispersion emulsifier and fixing agent for preventing sedimentation of microcapsules, preventing ink leakage from the pen tip, and an appropriate discharge amount, etc. Lubricants, antiseptic / antifungal agents, rust preventives, antifoaming agents, dyes, pigments and the like for preventing wear of the ball seats can be appropriately contained. When a coloring component such as a dye or a pigment is added, the decoloring ink component is decolored from the mixed state at the time of color development and the handwriting is in a discolored state.
Examples of the shear thinning agent include hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl pyrrolidone, and polyvinyl butyral when the ink liquid medium is an aromatic alcohol, and fatty acid amide when the ink liquid medium is a hydrocarbon solvent. In the case where the ink liquid medium is water, such as oxidized polyolefin, hydrogenated castor oil, dry silica, bentonite, etc., a water-soluble polymer compound can be used. Examples of the water-soluble polymer compound include gum arabic, gum tragacanth, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, casein, xanthene gum, dextran, welan gum, lambzan gum, alkasy gum, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, Sodium starch glycolate, sodium alginate, propylene glycol ester alginate, hydroxypropylated guar gum, methylcellulose, ethylcellulose, polyvinylpyrrolidone, polyvinylmethylether, polyacrylic acid, carboxyvinyl polymer, polyethylene oxide, copolymer of vinyl acetate and polyvinylpyrrolidone, Acrylic resin salt, acrylic acid and alkyl Copolymers of methacrylates or their salts in combination with one or more types may be used.

  Dispersing emulsifiers include anionic surfactants such as higher alcohol sulfates, liquid fatty acid sulfates, alkylallyl sulfonic acids, polyvinyl alcohol, polyoxyethylene alkyl ethers, sorbitan alkyl esters, polyoxyethylene sorbitan alkyls. Nonionic surfactants such as esters, cationic surfactants and amphoteric surfactants.

When water is used as the ink medium, antiseptic / antifungal agents include chloroacetamide, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2 -Methyl-4-isothiazolin-3-one, 2-pyridinethiol-1-oxide sodium salt, sodium dehydroacetate, sodium benzoate, sodium sorbate, potassium sorbate, thiabendazole, phenoxyethanol, sodium fluoride, 4- ( 2-nitrobutyl) morpholine, 1,3-dimorpholino-2-ethyl-2-nitripropane, 2-bromo-2-nitropropane-1,3-diol and the like.
Examples of the surface tension adjustment and antifoaming agent include silicon surfactants and fluorine surfactants.

When making an ink, use an aromatic alcohol as the solvent, and dissolve and use the leuco dye and developer, after dissolving the leuco dye and developer with a magnetic stirrer or three-one motor, Microcapsules can be added and dispersed using a roll mill, ball mill, sand grinder, attritor, homogenizer or the like.
When a hydrocarbon solvent or water is used as the solvent and the leuco dye and developer are finely divided, the fine particles of the leuco dye and developer and the microcapsules are roll mill, ball mill, sand grinder, atomizer. Can be dispersed with a lighter. The particle size is preferably about 1 to 10 μm.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example etc.

  As a method for producing a microcapsule, an in situ polymerization method or an interfacial polymerization method is known. The in situ polymerization method is a method of emulsifying a solution (oil layer) of a substance serving as a core substance of a capsule in water, adding a capsule film agent thereto, and polymerizing the film on oil droplets. The interfacial polymerization method is a method in which a hydrophobic organic solvent in which a capsule film agent is dissolved is emulsified in water, and then a hardener for the capsule film agent is added to form a film at the oil droplet interface.

Microcapsule 1 (in situ polymerization method)
(Creation of core material emulsion)
Water 20.0 parts by weight BL-25 (polyoxyethylene lauryl ether, manufactured by Nikko Chemicals Co., Ltd.)
2.2 parts by weight The above components were stirred for 1 hour with a magnetic stirrer and dissolved to obtain a polyoxyethylene lauryl ether aqueous solution.
To the above polyoxyethylene lauryl ether aqueous solution, the same amount of 2-ethylhexyl acetate (liquid having an ester group, boiling point 198.6 ° C.) is added and emulsified with a homogenizer at 9500 rpm for 1 hour, and 2-ethylhexyl acetate is added. An aqueous dispersion was obtained as droplets.
(Adjustment of capsule film)
Melamine monomer (Tokyo Chemical Industry Co., Ltd.) 10.0 parts by weight and formaldehyde (37% aqueous solution, Tokyo Chemical Industry Co., Ltd.) 20.0 parts by weight are mixed and adjusted to pH 9 with 25% aqueous sodium hydroxide solution. The mixture was adjusted and stirred with a magnetic stirrer at 80 ° C. for 1 hour to obtain a capsule membrane agent.
(Microencapsulation)
Alastar 703S (styrene-maleic acid copolymer 30 ± 1% aqueous solution, manufactured by Arakawa Chemical Co., Ltd.)
6.7 parts by weight water 15.5 parts by weight The above components were mixed and adjusted to pH 4.5 with acetic acid, and then stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid copolymer aqueous solution.
The same amount of the above styrene-maleic acid copolymer aqueous solution as the above polyoxyethylene lauryl ether aqueous solution is mixed and stirred with a magnetic stirrer for 1 hour. -A maleic acid copolymer was adsorbed.
Add 33.4 parts by weight of the capsule membrane agent to 66.6 parts by weight of the core material emulsion and stir with a magnetic stirrer for 2 hours to melamine on the surface of the core material droplet of 2-ethylhexyl acetate. A microcapsule dispersion obtained by polymerizing the resin was obtained. This was naturally dried to obtain microcapsules 1 having an average particle diameter of 18.0 μm and a film material of melamine resin.

Microcapsule 2 (in situ polymerization method)
In the production method of the microcapsule 1, the same procedure as in the case of the microcapsule 1 except that 2-ethylhexyl acetate was replaced with dibutyl maleate (liquid having an ester group, boiling point 280.6 ° C.). Microcapsules 2 in which the core material was coated with melamine resin were obtained.

Microcapsule 3 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin water solution.
20.0 parts by weight of diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.) is added to the styrene-maleic acid resin aqueous solution, and the mixture is stirred with a magnetic stirrer for 20 minutes to prepare an aqueous dispersion containing diisononyl phthalate as droplets. Obtained.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed, The capsule film agent was obtained by stirring with a magnetic stirrer.
(Microencapsulation)
60.0 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 2 hours. A microcapsule dispersion in which urea resin was polymerized on the surface of the core material droplet of diisononyl phthalate was obtained. This was naturally dried to obtain microcapsules 3 having an average particle diameter of 12.0 μm and a film material of melamine resin.

Microcapsule 4 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight Each of the above components was stirred with a magnetic stirrer for 1 hour to obtain a dissolved styrene maleic acid resin aqueous solution.
Ethylcyclohexane (boiling point 132 ° C.) 18.0 parts by weight p-tolyl phenylacetate (solid having an ester group (crystalline))
2.0 parts by weight The above components were stirred with a magnetic stirrer for 1 hour to obtain an ethylcyclohexane solution of p-tolyl phenylacetate.
The aqueous styrene maleic acid resin solution and the ethylcyclohexane solution of phenylacetic acid p-tolyl were stirred with a magnetic stirrer for 20 minutes to obtain an aqueous dispersion in which the ethylcyclohexane solution of phenylacetic acid p-tolyl was used as droplets.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 18.0 parts by weight, resorcinol (urea resin cross-linking agent) 1.6 parts by weight and water 16.0 parts by weight were mixed, The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
Adjust 60.0 parts by weight of the core material emulsion to pH 4.2 with acetic acid, add 35.6 parts by weight of the capsule membrane agent, adjust the liquid temperature to 60 ° C., and stir for 3 hours with a magnetic stirrer. A microcapsule dispersion having an average particle size of 12.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of ethylcyclohexane solution of p-tolyl phenylacetate. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 4 whose film material was urea resin.

Microcapsule 5 (in situ polymerization method)
In the production method of the above microcapsule 4, ethylcyclohexane, 18.0 parts by weight and 2.0 parts by weight of phenylacetate p-tolyl are mixed with 18.0 parts by weight of hexyl acetate (liquid having an ester group, boiling point 170 ° C.) and phenyl. The core substance of the hexyl acetate solution of p-tolyl phenylacetate was the same as in the case of the microcapsule 4 except that it was replaced with 2.0 parts by weight of p-tolyl acetate (solid (crystalline) having an ester group). Microcapsules 5 having an average particle diameter of 12.0 μm coated with urea resin were obtained.

Microcapsule 6 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were stirred with a magnetic stirrer for 1 hour to obtain a dissolved styrene-maleic acid resin aqueous solution.
Cyclohexylbenzene 5.0 parts by weight 2-ethylhexyl acetate (liquid having an ester group, boiling point 200 ° C.)
15.0 parts by weight Each of the above components was stirred with a magnetic stirrer for 1 hour to obtain a solution of cyclohexylbenzene and 2-ethylhexyl acetate.
The aqueous styrene maleic acid resin solution and a solution of cyclohexylbenzene and 2-ethylhexyl acetate were stirred at 6500 rpm for 10 minutes with a homogenizer, and an aqueous dispersion in which a solution of cyclohexylbenzene and 2-ethylhexyl acetate was used as droplets was obtained. Obtained.
(Adjustment of capsule film)
Becamine M-3 (melamine resin prepolymer, non-volatile content 80%, manufactured by DIC Corporation) 22.5 parts by weight and 15.0 parts by weight of water were mixed and stirred with a magnetic stirrer to obtain a capsule film agent It was.
(Microencapsulation)
60.0 parts by weight of the core material emulsion is adjusted to pH 4.8 with acetic acid, 37.5 parts by weight of the capsule membrane agent is added, the liquid temperature is adjusted to 60 ° C., and the mixture is stirred with a magnetic stirrer for 3 hours. A microcapsule dispersion having an average particle size of 9.0 μm was obtained by polymerizing a melamine resin on the surface of the core material droplet of a solution of cyclohexylbenzene and 2-ethylhexyl acetate. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 6 whose film material was melamine resin.

Microcapsule 7 (in situ polymerization method)
In the production method of the microcapsule 3, 20.0 parts by weight of diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.) is mixed with 18.0 parts by weight of diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.) and phenylacetic acid p- The core substance of the diisononyl phthalate solution of p-tolyl phenylacetate was replaced with urea resin in the same manner as in the microcapsule 3 except that it was replaced with 2.0 parts by weight of tolyl (solid having an ester group (crystalline)). A coated microcapsule 7 having an average particle diameter of 12.0 μm was obtained.

Microcapsule 8 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were stirred with a magnetic stirrer for 1 hour to obtain a dissolved styrene-maleic acid resin aqueous solution.
The aqueous styrene-maleic acid resin solution and 20.0 parts by weight of diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.) are stirred with a homogenizer at 9500 rpm for 10 minutes to obtain an aqueous dispersion having diisononyl phthalate as droplets. It was.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed. The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
Adjust 60.0 parts by weight of the core material emulsion to pH 4.2 with acetic acid, add 40.5 parts by weight of the capsule membrane agent, adjust the liquid temperature to 60 ° C., and stir for 3 hours with a magnetic stirrer. A microcapsule dispersion having an average particle size of 4.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of diisononyl phthalate. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 8 whose film material was urea resin.

Microcapsule 9 (in situ polymerization method)
(Creation of core material emulsion)
NIKKOL MYS-55V (polyethylene glycol monostearate, manufactured by Nikko Chemicals Corporation)
0.4 parts by weight of water 20.0 parts by weight The above components were stirred for 1 hour with a magnetic stirrer and dissolved to obtain a polyethylene glycol monostearate aqueous solution.
Dibutyl ether (liquid having an ether group) 18.0 parts by weight Hilac 111 (ketone resin (amorphous), manufactured by Hitachi Chemical Co., Ltd.)
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a dibutyl ether solution of a ketone resin.
20.0 parts by weight of a dibutyl ether solution of a ketone resin is added to 20.4 parts by weight of the aqueous polyethylene glycol stearate solution, and one pass is performed with a homogenizer (Star Burst Mini, manufactured by Sugino Machine Co., Ltd.) at a pressure of 80 MPa. Then, an aqueous dispersion having droplets of a dibutyl ether solution of a ketone resin was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
6.5 weight part water 15.0 weight part The said each component was mixed and it stirred with the magnetic stirrer for 1 hour, and obtained styrene- maleic acid resin aqueous solution.
A styrene-maleic acid resin aqueous solution is mixed with an aqueous dispersion of the above-mentioned ketone resin dibutyl ether solution as droplets and stirred at 13500 rpm for 10 minutes with a homogenizer. Maleic acid resin was adsorbed.
61.9 parts by weight of the core material emulsified liquid adsorbed with the styrene-maleic acid resin was adjusted to pH 4.2 with acetic acid, and 40.5 parts by weight of the capsule film agent was added. The mixture was stirred for 2 hours to obtain a microcapsule dispersion having an average particle size of 0.5 μm in which urea resin was polymerized on the surface of the core material droplet of a dibutyl ether solution of ketone resin. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 9 whose film material was urea resin.

Microcapsule 10 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having ester group, boiling point 170 ° C.) 18.0 parts by weight Hilac 111 (ketone resin (amorphous), manufactured by Hitachi Chemical Co., Ltd.)
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a hexyl acetate solution of a ketone resin.
20.0 parts by weight of a ketone resin hexyl acetate solution is added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture is stirred with a magnetic stirrer for 20 minutes. A liquid was obtained.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed. The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
60.0 parts by weight of the above core substance emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the above capsule membrane agent is added, and stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 2 hours. A microcapsule dispersion having an average particle diameter of 12.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of a hexyl acetate solution of the resin. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 10 whose film material was urea resin.

Microcapsule 11 (in situ polymerization method)
(Creation of core material emulsion)
Water 20.0 parts by weight BL-25 (polyoxyethylene lauryl ether, manufactured by Nikko Chemicals Co., Ltd.)
2.2 parts by weight The above components were stirred for 1 hour with a magnetic stirrer and dissolved to obtain a polyoxyethylene lauryl ether aqueous solution.
ALASTAR 703S (styrene-maleic acid 30 ± 1% aqueous solution, manufactured by Arakawa Chemical Co., Ltd.)
13.3 parts by weight of water 31.1 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Isobutyl acetate (liquid with ester group, boiling point 116.6 ° C)
20.0 parts by weight BS-2 (polyoxyethylene stearyl ether, Nikko Chemicals Corporation)
2.2 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain an isobutyl acetate solution of polyoxyethylene stearyl ether.
22.2 parts by weight of an isobutyl acetate solution of polyoxyethylene stearyl ether is added to 22.2 parts by weight of the above polyoxyethylene lauryl ether aqueous solution, and the pressure is 80 MPa with a homogenizer (Star Burst Mini, manufactured by Sugino Machine Co., Ltd.). 2 passes. 44.4 parts by weight of a styrene-maleic acid resin aqueous solution was added thereto, and the mixture was further stirred with a magnetic stirrer for 1 hour to obtain an aqueous dispersion in which an isobutyl acetate solution of polyoxyethylene stearyl ether was used as droplets.
(Adjustment of capsule film)
Melamine monomer (Tokyo Chemical Industry Co., Ltd.) 10.0 parts by weight and formaldehyde (37% aqueous solution, Tokyo Chemical Industry Co., Ltd.) 20.0 parts by weight are mixed and adjusted to pH 9 with 25% aqueous sodium hydroxide solution. The mixture was adjusted and stirred with a magnetic stirrer at 80 ° C. for 1 hour to obtain a capsule membrane agent.
(Microencapsulation)
Alastar 703S (styrene-maleic acid copolymer 30 ± 1% aqueous solution, manufactured by Arakawa Chemical Co., Ltd.)
13.3 parts by weight of water 31.1 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid copolymer (resin) aqueous solution.
A water dispersion of polyoxyethylene stearyl ether in isobutyl acetate is mixed with an aqueous dispersion of styrene-maleic acid resin and stirred with a magnetic stirrer for 1 hour to form droplets of polyoxyethylene stearyl ether in isobutyl acetate. A styrene-maleic acid resin was adsorbed on the surface of the film.
The core material emulsion 88.8 parts by weight of the styrene-maleic acid resin adsorbed is adjusted to pH 4.8 with acetic acid, 30.0 parts by weight of the capsule film agent is added, and the mixture is stirred with a magnetic stirrer for 2 hours. Thus, a microcapsule dispersion having an average particle size of 0.08 μm was obtained by polymerizing a melamine resin on the surface of the core material droplet of an isobutyl acetate solution of polyoxyethylene stearyl ether. This was naturally dried to obtain microcapsules 11 whose film material was melamine resin.

Microcapsule 12 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having ester group, boiling point 170 ° C.) 18.0 parts by weight 1,3-diphenyl-1,3-propanedione (solid having ketone group (crystalline))
2.0 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a hexyl acetate solution of 1,3-diphenyl-1,3-propanedione.
To 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, 20.0 parts by weight of a hexyl acetate solution of 1,3-diphenyl-1,3-propanedione is added and stirred at 13500 rpm for 10 minutes with a homogenizer. An aqueous dispersion having droplets of a hexyl acetate solution of 3-diphenyl-1,3-propanedione was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60.0 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. A microcapsule dispersion having an average particle size of 3.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of a hexyl acetate solution of 1,3-diphenyl-1,3-propanedione.
After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 12 whose film material was urea resin.

Microcapsule 13 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having an ester group, boiling point 170 ° C.) 18.0 parts by weight cetanol (solid having an aliphatic hydroxyl group (crystalline)) 2.0 parts by weight The above components are dissolved with a magnetic stirrer for 1 hour, and cetanol Of hexyl acetate was obtained.
20.0 parts by weight of cetanol acetate hexyl acetate solution is added to 40.0 parts by weight of the above styrene-maleic acid resin aqueous solution, and the mixture is stirred with a homogenizer at 6500 rpm for 10 minutes, and dispersed in water with cetanol acetate hexyl acetate as droplets. A liquid was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the above core substance emulsion was adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the above capsule membrane agent was added, and the mixture was stirred with a magnetic stirrer at 60 ° C. for 3 hours. A microcapsule dispersion having an average particle size of 7.0 μm obtained by polymerizing urea resin on the surface of the core material droplet of the hexyl solution was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 13 whose film material was urea resin.

Microcapsule 14 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having an ester group, boiling point: 170 ° C.) 18.0 parts by weight 4-methoxybenzophenone (solid having a ketone group and an ether group (crystalline))
2.0 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a hexyl acetate solution of 4-methoxybenzophenone.
To 40.0 parts by weight of the aqueous styrene-maleic acid resin solution, 20.0 parts by weight of hexyl acetate solution of 4-methoxybenzophenone is added and stirred for 10 minutes at 17500 rpm with a homogenizer, and hexyl acetate solution of 4-methoxybenzophenone is added. An aqueous dispersion was obtained as droplets.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. A microcapsule dispersion having an average particle size of 2.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of hexyl acetate solution of benzophenone. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 14 whose film material was urea resin.

Microcapsule 15 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having an ester group, boiling point 170 ° C.) 18.0 parts by weight methyl 3,4,5-trimethoxybenzoate (solid having an ester group and an ether group (crystalline))
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a hexyl acetate solution of methyl 3,4,5-trimethoxybenzoate.
20.0 parts by weight of a hexyl acetate solution of methyl 3,4,5-trimethoxybenzoate is added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture is stirred with a homogenizer at 13500 rpm for 10 minutes. An aqueous dispersion having droplets of hexyl acetate solution of methyl, 5-trimethoxybenzoate was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 27.6 parts by weight, resorcinol (urea resin cross-linking agent) 2.5 parts by weight and water 16.0 parts by weight, magnetic The capsule film was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 46.1 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. A microcapsule dispersion having an average particle size of 3.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of a hexyl acetate solution of methyl 5-trimethoxybenzoate. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 15 whose film material was urea resin.

Microcapsule 16 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
2-ethylhexyl acetate (liquid having an ester group, boiling point 198.6 ° C.)
19.8 parts by weight Triphenyl phosphate (solid having an ether group) 0.2 part by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a 2-ethylhexyl acetate solution of triphenyl phosphate.
20.0 parts by weight of a triethyl phosphate 2-ethylhexyl acetate solution is added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture is stirred with a homogenizer at 13500 rpm for 10 minutes. -Obtain an aqueous dispersion in which ethylhexyl solution is used as droplets.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 20.0 parts by weight, resorcinol (urea resin cross-linking agent) 1.8 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 37.8 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. for 3 hours with a magnetic stirrer. A microcapsule dispersion having an average particle size of 1.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of phenyl 2-ethylhexyl acetate solution. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 16 whose film material was urea resin.

Microcapsule 17 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Amyl acetate (liquid with ester group, boiling point 149.2 ° C)
19.0 parts by weight methyl 4-acetoxybenzoate (solid having an ester group (crystalline))
1.0 part by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain an amyl acetate solution of methyl 4-acetoxybenzoate.
To 40.0 parts by weight of the aqueous styrene-maleic acid resin solution, 20.0 parts by weight of an amyl acetate solution of methyl 4-acetoxybenzoate was added and stirred for 10 minutes at 13500 rpm with a homogenizer. An aqueous dispersion having droplets of amyl acetate solution was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 20.0 parts by weight, resorcinol (urea resin cross-linking agent) 1.8 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60.0 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 37.8 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. for 3 hours with a magnetic stirrer. -A microcapsule dispersion having an average particle diameter of 5.0 µm was obtained by polymerizing urea resin on the surface of the core material droplet of an amyl acetate solution of methyl acetoxybenzoate. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 17 whose film material was urea resin.

Microcapsule 18 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.)
18.0 parts by weight p-tolyl phenylacetate (solid having an ester group (crystalline))
2.0 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a diisononyl phthalate solution of phenylacetic acid p-tolyl.
To 40.0 parts by weight of the above aqueous styrene-maleic acid resin solution, 20.0 parts by weight of a diisononyl phthalate solution of p-tolyl phenylacetate was added and stirred at 9500 rpm for 10 minutes with a homogenizer. An aqueous dispersion having the solution as droplets was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. -A microcapsule dispersion liquid having an average particle size of 5.0 µm obtained by polymerizing urea resin on the surface of the core material droplet of diisononyl phthalate solution of tolyl was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 18 whose film material was urea resin.

Microcapsule 19 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Ethylcyclohexane (boiling point 132 ° C.) 18.0 parts by weight NIKKOL Hexaglyn 3-S (Ester group, solid having ether group (amorphous), hexaglyceryl tristearate, manufactured by Nikko Chemicals Co., Ltd.)
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain an ethylcyclohexane solution of hexaglyceryl tristearate.
To 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, 20.0 parts by weight of hexaglyceryl tristearate solution in ethylcyclohexane was added and stirred at 6500 rpm for 10 minutes with a homogenizer. An aqueous dispersion having the solution as droplets was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 18.0 parts by weight, resorcinol (urea resin cross-linking agent) 1.6 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
Tristearic acid was prepared by adjusting 60 parts by weight of the above core substance emulsion to pH 4.2 with acetic acid, adding 35.6 parts by weight of the above capsule membrane agent, and stirring with a magnetic stirrer at 60 ° C. for 3 hours. A microcapsule dispersion liquid having an average particle diameter of 7.0 μm obtained by polymerizing urea resin on the surface of the core material droplet of an ethylcyclohexane solution of hexaglyceryl was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 19 whose film material was urea resin.

Microcapsule 20 (interfacial polymerization method)
(Creation of core material emulsion)
Water 93.0 parts by weight POVAL 117 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) 7.0 parts by weight The above components were mixed and stirred with a magnetic stirrer at 60 ° C. for 5 hours to obtain an aqueous polyvinyl alcohol solution.
Isoamyl acetate (liquid with ester group, boiling point 142.1 ° C)
88.4 parts by weight BS-2 (polyoxyethylene stearyl ether, Nikko Chemicals)
4.7 parts by weight terephthalic acid chloride (capsule film agent, manufactured by Taiyo Nippon Sanso Co., Ltd.) 6.9 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour, and polyoxyethylene stearyl ether, terephthalic acid chloride and An isoamyl acetate solution was obtained.
To 48.4 parts by weight of the above-mentioned aqueous polyvinyl alcohol solution, 42.0 parts by weight of an isoamyl acetate solution of polyoxyethylene stearyl ether and terephthalic acid chloride is added and stirred at 13500 rpm for 10 minutes with a homogenizer. An aqueous dispersion having droplets of isoamyl acetate solution with terephthalic acid chloride was obtained.
(Adjustment of curing agent)
15.0 parts by weight of diethylenetriamine (curing agent for capsule film agent) and 85.0 parts by weight of water were mixed and stirred with a magnetic stirrer to obtain a diethylenetriamine aqueous solution.
(Microencapsulation)
Add 90.4 parts by weight of the above core substance emulsion and 9.6 parts by weight of diethylenetriamine aqueous solution and stir with a magnetic stirrer for 3 hours to obtain a core substance solution of an isoamyl acetate solution of polyoxyethylene stearyl ether and terephthalic acid chloride. A microcapsule dispersion liquid having an average particle size of 10.0 μm was obtained by polymerizing polyamide on the surface of the droplet by reaction of terephthalic acid chloride with diethylenetriamine. This was naturally dried to obtain a microcapsule 20 whose film material was a polyamide resin.

Microcapsule 21 (in situ polymerization method)
(Creation of core material emulsion)
NIKKOL MYS-55V (polyethylene glycol monostearate, manufactured by Nikko Chemicals Corporation)
0.4 parts by weight of water 20.0 parts by weight The above components were stirred for 1 hour with a magnetic stirrer and dissolved to obtain a polyethylene glycol monostearate aqueous solution.
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
6.5 weight part water 15.0 weight part The said each component was mixed and it stirred with the magnetic stirrer for 1 hour, and obtained styrene- maleic acid resin aqueous solution.
2-ethylhexyl acetate (liquid having an ester group, boiling point 198.6 ° C.)
19.0 parts by weight Halon 110H (ketone resin, manufactured by Honshu Chemical Co., Ltd.) 1.0 part by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a 2-ethylhexyl acetate solution of the ketone resin.
To 20.4 parts by weight of the aqueous polyethylene glycol monostearate solution, 20.0 parts by weight of a 2-ethylhexyl acetate solution of a ketone resin is added, and the pressure is 80 MPa with a homogenizer (Star Burst Mini, manufactured by Sugino Machine Co., Ltd.) Take one pass. 21.5 parts by weight of a styrene-maleic acid resin aqueous solution was added thereto, and the mixture was further stirred and emulsified with a magnetic stirrer for 3 hours to obtain an aqueous dispersion having a 2-ethylhexyl acetate solution of a ketone resin as droplets.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 20.0 parts by weight, resorcinol (urea resin cross-linking agent) 1.8 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
61.9 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 37.8 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. The urea resin was polymerized on the surface of the core material droplet of a 2-ethylhexyl acetate solution of the resin to obtain a microcapsule dispersion having an average particle size of 1.0 μm. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 21 whose film material was urea resin.

Preparation of microcapsules 22 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Phenyl acetate (liquid having ester group, boiling point 195 ° C.) 18.0 parts by weight behenyl alcohol (solid having aliphatic hydroxyl group (amorphous))
2.0 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a phenyl acetate solution of behenyl alcohol.
20.0 parts by weight of a phenyl acetate solution of behenyl alcohol was added to 40.0 parts by weight of the aqueous styrene-maleic acid resin solution, stirred for 10 minutes at 17500 rpm with a homogenizer, and dispersed in water with the phenyl acetate solution of behenyl alcohol as droplets. A liquid was obtained.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the above core substance emulsion was adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the above capsule membrane agent was added, and the mixture was stirred for 3 hours with a magnetic stirrer at a liquid temperature of 60 ° C. to be acetic acid of behenyl alcohol. A microcapsule dispersion liquid having an average particle size of 1.0 μm obtained by polymerizing urea resin on the surface of the core material droplet of the phenyl solution was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 22 whose film material was urea resin.

Production of microcapsule 23 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Phenyl acetate (boiling point 195 ° C.) 18.0 parts by weight NIKKOL MYS-10 (polyester glycol monostearate having an ester group and an ether group, manufactured by Nikko Chemicals Co., Ltd.)
2.0 parts by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a phenyl acetate solution of polyethylene glycol monostearate.
20.0 parts by weight of a polyethylene glycol monostearate solution is added to 40.0 parts by weight of the aqueous styrene-maleic acid resin solution, and the mixture is stirred with a homogenizer at 17500 rpm for 10 minutes. An aqueous dispersion having the solution as droplets was obtained.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed. The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
60 parts by weight of the above core substance emulsion was adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the above capsule membrane agent was added, and the mixture was stirred for 3 hours with a magnetic stirrer at a liquid temperature of 60 ° C. A microcapsule dispersion having an average particle size of 1.0 μm was obtained by polymerizing urea resin on the core material droplet surface of a phenyl acetate solution of polyethylene glycol. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 23 whose film material was urea resin.

Preparation of microcapsules 24 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Phenyl acetate (boiling point 195 ° C.) 18.0 parts by weight NIKKOL MGS-F20 (glyceryl monostearate having an ester group and an aliphatic hydroxyl group, manufactured by Nikko Chemicals Co., Ltd.)
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a phenyl acetate solution of glyceryl monostearate.
20.0 parts by weight of a glyceryl monostearate solution is added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture is stirred for 10 minutes at 17500 rpm with a homogenizer. A phenyl acetate solution of glyceryl monostearate is added. An aqueous dispersion is obtained as droplets.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the above core substance emulsion was adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the above capsule membrane agent was added, and the mixture was stirred for 3 hours with a magnetic stirrer at a liquid temperature of 60 ° C. A microcapsule dispersion having an average particle size of 1.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of a phenyl acetate solution of glyceryl. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 24 whose film material was urea resin.

Preparation of microcapsule 25 (interfacial polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.6 parts by weight of water 16.8 parts by weight The above components were mixed and stirred for 1 hour with a magnetic stirrer to obtain a styrene-maleic acid resin aqueous solution.
Hexyl acetate (liquid having ester group, boiling point 170 ° C.) 18.0 parts by weight Halon 110H (ketone resin, manufactured by Honshu Chemical Co., Ltd.) 2.0 parts by weight Coronate HXLV (capsule film agent, polyisocyanate, Nippon Polyurethane Industry ( Made by Co., Ltd.)
7.6 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a hexyl acetate solution of a ketone resin and a polyisocyanate.
27.6 parts by weight of a hexyl acetate solution of a ketone resin and a polyisocyanate is added to 25.4 parts by weight of the aqueous styrene-maleic acid resin solution, and the mixture is stirred for 10 minutes at 21500 rpm with a homogenizer. An aqueous dispersion having droplets of hexyl acetate solution was obtained.
(Adjustment of curing agent)
0.3 parts by weight of diethylenetriamine (curing agent for capsule film agent) and 2.2 parts by weight of water were mixed and stirred with a magnetic stirrer to obtain a diethylenetriamine aqueous solution.
(Microencapsulation)
Add 53.0 parts by weight of the above core substance emulsion and 2.5 parts by weight of diethylenetriamine aqueous solution and stir with a magnetic stirrer for 3 hours to form a hexyl acetate solution of ketone resin and polyisocyanate on the core substance droplet surface. Thus, a microcapsule dispersion 25 having an average particle size of 2.0 μm was obtained by polymerizing polyurethane by the reaction of polyisocyanate and diethylenetriamine.

Microcapsule 26 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Phenyl acetate (boiling point 195 ° C.) 18.0 parts by weight Synthetic resin AP (ketone resin (amorphous), manufactured by Huls (Germany))
2.0 parts by weight Each of the above components was dissolved with a magnetic stirrer for 1 hour to obtain a phenyl acetate solution of a ketone resin.
20.0 parts by weight of a ketone resin phenyl acetate solution was added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture was stirred with a homogenizer at 17500 rpm for 10 minutes. An aqueous dispersion was obtained.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed. The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. A microcapsule dispersion having an average particle size of 1.0 μm obtained by polymerizing urea resin on the surface of the core material droplet of the phenyl acetate solution was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 26 whose film material was urea resin.

Microcapsule 27 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
Diisononyl phthalate (liquid having an ester group and a boiling point of 403 ° C.)
19.0 parts by weight NIKKOL BS-2 (solid having an ether group (amorphous), polyoxyethylene alkyl ether, manufactured by Nikko Chemicals Co., Ltd.)
1.0 part by weight The above components were dissolved with a magnetic stirrer for 1 hour to obtain a diisononyl phthalate solution of polyoxyethylene alkyl ether.
20.0 parts by weight of a polyoxyethylene alkyl ether diisononyl phthalate solution is added to 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, and the mixture is stirred with a magnetic stirrer for 20 minutes, and the polyoxyethylene alkyl ether diisononyl phthalate solution is added. A water dispersion was obtained in the form of droplets.
(Adjustment of capsule film)
22.5 parts by weight of becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation), 2.0 parts by weight of resorcinol (urea resin cross-linking agent) and 16.0 parts by weight of water were mixed. The capsule membrane agent was obtained by stirring with a tic stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. for 3 hours with a magnetic stirrer. A microcapsule dispersion having an average particle size of 9.0 μm was obtained by polymerizing urea resin on the surface of the core material droplet of a diisononyl phthalate solution of alkyl ether. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 27 whose film material was urea resin.

Microcapsule 28 (in situ polymerization method)
(Creation of core material emulsion)
Sumirez Resin 402K (35% aqueous solution of styrene-maleic acid resin, manufactured by Taoka Chemical Co., Ltd.)
8.0 parts by weight of water 32.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain a styrene-maleic acid resin aqueous solution.
To 40.0 parts by weight of the styrene-maleic acid resin aqueous solution, 20.0 parts by weight of 4-tert-butylcyclohexanone (solid (crystalline) having a ketone group (melting point: 50 ° C.)) is added, and the homogenizer is 6500 rpm at 60 ° C. At 10 minutes to obtain an aqueous dispersion of 4-tert-butylcyclohexanone.
(Adjustment of capsule film)
Becamine J300S (urea resin prepolymer, non-volatile content 70%, manufactured by DIC Corporation) 22.5 parts by weight, resorcinol (urea resin crosslinking agent) 2.0 parts by weight and water 16.0 parts by weight, magnetic The capsule membrane agent was obtained by stirring with a stirrer.
(Microencapsulation)
60 parts by weight of the core material emulsion is adjusted to pH 4.2 with acetic acid, 40.5 parts by weight of the capsule membrane agent is added, and the mixture is stirred at a liquid temperature of 60 ° C. with a magnetic stirrer for 3 hours. -A microcapsule dispersion liquid having an average particle size of 9.0 µm obtained by polymerizing urea resin on the surface of the core material droplet of butylcyclohexanone was obtained. After 1.0 part by weight of PVP K-15 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.) was dissolved in this dispersion, this was naturally dried to obtain microcapsules 28 whose film material was urea resin.

(Base ink composition 1)
S-205 (black leuco dye, 2′-anilino-6 ′-(N-ethyl-N-isopentylamino) -3′-methylspiro [phthalide-3,9 ′ [9H] xanthene], Yamada Chemical Co., Ltd. Made)
18.85 parts by weight Tamanol PA (Developer, phenol resin, manufactured by Arakawa Chemical Industries, Ltd.)
17.65 parts by weight 2,2-bis (4-hydroxyphenyl) propane (developer)
6.36 parts by weight Resorcinol 12.61 parts by weight benzyl alcohol (ink liquid medium) 37.65 parts by weight PVP-K90 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.)
0.05 parts by weight PVB-4000-1 (polyvinyl butyral, manufactured by Denki Kagaku Kogyo Co., Ltd.)
0.48 parts by weight NIKKOL MGO (glyceryl oleate, manufactured by Nikko Chemicals)
6.36 parts by weight The above components were stirred with a magnetic stirrer at 50 ° C. for 1 hour to obtain a base ink.

(Base ink composition 2)
S-205 (black leuco dye, 2′-anilino-6 ′-(N-ethyl-N-isopentylamino) -3′-methylspiro [phthalide-3,9 ′ [9H] xanthene], Yamada Chemical Co., Ltd. Made)
4.00 parts by weight benzyl alcohol 45.40 parts by weight PVP-K90 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.)
0.10 parts by weight ESREC BM-2 (polyvinyl butyral, manufactured by Sekisui Chemical Co., Ltd.)
0.50 parts by weight Propyl gallate 10.00 parts by weight 2,2-bis (4-hydroxyphenyl) propane 3.00 parts by weight Tamanol 758 (Novolac type phenolic resin, manufactured by Arakawa Chemical Co., Ltd.)
7.00 parts by weight The above components were stirred with a magnetic stirrer at 50 ° C. for 1 hour to obtain a base ink 2.

Example 1
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 1 were dispersed by a roll mill to obtain a black ink composition.

Example 2
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 2 were dispersed by a roll mill to obtain a black ink composition.

Example 3
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 3 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 4
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 4 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 5
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 5 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 6
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 6 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 7
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 7 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 8
75 parts by weight of the base ink composition 1 and 25 parts by weight of the microcapsules 8 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 9
70 parts by weight of the base ink composition 1 and 30 parts by weight of the microcapsules 9 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 10
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 10 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 11
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 11 were dispersed with a roll mill to obtain a black ink composition.

Example 12
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 12 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 13
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 13 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 14
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 14 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 15
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 15 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 16
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 16 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 17
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 17 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 18
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 18 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 19
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 19 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 20
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 20 were dispersed by a roll mill to obtain a black ink composition.

Example 21
85 parts by weight of the base ink composition 1 and 15 parts by weight of the microcapsules 21 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 22
70 parts by weight of the base ink composition 2 and 30 parts by weight of the microcapsules 22 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 23
70 parts by weight of the base ink composition 2 and 30 parts by weight of the microcapsules 23 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 24
70 parts by weight of the base ink composition 2 and 30 parts by weight of the microcapsules 24 were dispersed with a magnetic stirrer to obtain a black ink composition.

Example 25
(Leuco dye-Developer pigment 1)
S-205 (black leuco dye, 2′-anilino-6 ′-(N-ethyl-N-isopentylamino) -3′-methylspiro [phthalide-3,9 ′ [9H] xanthene], Yamada Chemical Co., Ltd. Made)
15 parts by weight 2,2-bis (4-hydroxyphenyl) propane (developer)
45 parts by weight Acetone 40 parts by weight Each of the above components is stirred with a magnetic stirrer for 1 hour and then allowed to stand at room temperature for 3 days to evaporate acetone. Thereafter, the mixture was pulverized in a mortar to obtain pigment 1 of leuco dye-developer.
(Ink)
Leuco dye-developer pigment 1 20.0 parts by weight water 21.5 parts by weight ethylene glycol 10.0 parts by weight Microcapsule dispersion 25 40.0 parts by weight Kelzan AR 6% aqueous solution (xanthan gum, manufactured by Sanki Co., Ltd.) 7.0 parts by weight Demol EP (polycarboxylic acid type polymer surfactant, manufactured by Kao Corporation)
1.5 parts by weight The above components except for the microcapsule dispersion 25 and the Kelzan AR 6% aqueous solution were dispersed for 24 hours with a ball mill, and then the microcapsule dispersion 25 was added and further dispersed for 1 hour. Thereafter, a 6% aqueous solution of Kelzan AR was added and stirred with a magnetic stirrer for 3 hours to obtain a black ink composition.

Example 26
(Leuco dye-Developer pigment 2)
S-205 (black leuco dye, 2′-anilino-6 ′-(N-ethyl-N-isopentylamino) -3′-methylspiro [phthalide-3,9 ′ [9H] xanthene], Yamada Chemical Co., Ltd. Made)
4.0 parts by weight Mizuka Ace # 400 (Developer, acid clay, manufactured by Mizusawa Chemical Co., Ltd.)
12.0 parts by weight Acetone 30.0 parts by weight Each of the above components was treated with a ball mill for 24 hours, and then the acetone was evaporated to obtain a black pigment.
(Ink)
Leuco dye—Developer pigment 2 16.0 parts by weight benzyl alcohol 48.4 parts by weight PVP-K90 (polyvinylpyrrolidone, manufactured by ISP Japan Co., Ltd.)
0.1 parts by weight ESREC BM-2 (polyvinyl butyral, manufactured by Sekisui Chemical Co., Ltd.)
0.5 parts by weight YS Polystar S145 (terpene phenol, manufactured by Yasuhara Chemical Co., Ltd.)
7.0 parts by weight The above components were stirred with a magnetic stirrer at 70 ° C. for 1 hour, then 30 parts by weight of microcapsules 26 were added, stirred with a homogenizer for 30 minutes, filtered under pressure using 5A filter paper, and black oil-based ink A composition was obtained.

Example 27
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 27 were dispersed with a magnetic stirrer to obtain a black ink composition.

Comparative Example 1
Thermochromic microcapsule pigment (interfacial polymerization method)
(Creation of core material emulsion)
2- (2-Chloroanilino) -6-di-n-butylaminofluorane (black leuco dye)
4.5 parts by weight 1,1-bis (4′-hydroxyphenyl) n-decane (developer)
4.5 parts by weight 1,1-bis (4′-hydroxyphenyl) hexafluoropropane (developer)
7.5 parts by weight 4-benzyloxyphenylethyl caprate (decolorant) 50.0 parts by weight The above components were stirred with a magnetic stirrer at 50 ° C. for 1 hour to obtain thermochromic compound 1.
Thermochromic compound 1 56.5 parts by weight Coronate HX (polyisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd.)
30.0 parts by weight Isobutyl acetate 40.0 parts by weight Each of the above components was stirred with a magnetic stirrer for 1 hour to obtain a thermochromic compound and an isobutyl acetate solution of polyisocyanate.
Water 92.0 parts by weight PVA205 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) 8.0 parts by weight The above components were mixed and stirred with a magnetic stirrer for 1 hour to obtain an aqueous polyvinyl alcohol solution.
70.0 parts by weight of a thermochromic compound and a polyisocyanate isobutyl acetate solution are added to 66.5 parts by weight of a polyvinyl alcohol aqueous solution, and the mixture is stirred for 20 minutes at 13500 rpm with a homogenizer, and the thermochromic compound and isobutyl acetate of a polyisocyanate are mixed. An aqueous dispersion having the solution as droplets was obtained.
(Adjustment of curing agent)
A mixture of 3.0 parts by weight of diethylenetriamine (curing agent for capsule film) and 27.0 parts by weight of water was stirred with a magnetic stirrer to obtain a diethyltriamine aqueous solution.
(Microencapsulation)
Add 136.5 parts by weight of the above core substance emulsion and 30.0 parts by weight of diethylenetriamine aqueous solution and stir with a magnetic stirrer for 3 hours on the core substance droplet surface of the isobutyl acetate solution of the discolorable compound and polyisocyanate. Thus, a microcapsule dispersion having an average particle size of 3.0 μm was obtained by polymerizing polyurethane by the reaction of polyisocyanate and diethylenetriamine.
(Ink)
Microcapsule dispersion 25.70 parts by weight Succinoglucan (shear thinning agent, manufactured by Sanki Co., Ltd.) 0.20 parts by weight urea 5.50 parts by weight glycerin 7.50 parts by weight Nopco SW-WET-366 ( Non-ionic surfactant, manufactured by San Nopco)
0.03 parts by weight FS Antifoam 013A (silicone defoaming agent, manufactured by Toray Dow Corning Co., Ltd.)
0.15 parts by weight Proxel XL-2 (benzoisothiazolin-3-one, manufactured by ICI Japan Ltd.)
0.10 parts by weight Plysurf A212C (polyoxyalkylene alkyl ether phosphate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
0.50 parts by weight Triethanolamine 0.50 parts by weight Water 59.82 parts by weight The above components except for succinoglucan are dispersed with a magnetic stirrer, succinoglucan is added, and the mixture is stirred with a magnetic stirrer for 2 hours. Then, it was left to stand at −20 ° C. for 24 hours to obtain a black ink composition.

Comparative Example 2
A black ink composition was obtained in the same manner as in Comparative Example 1 except that the thermochromic compound 1 of Comparative Example 1 was changed to the following thermochromic compound 2.
(Thermochromic compound 2)
2- (2-Chloroanilino) -6-di-n-butylaminofluorane (black leuco dye)
6.8 parts by weight of 1,1-bis (4′-hydroxyphenyl) n-decane (developer)
6.8 parts by weight 1,1-bis (4′-hydroxyphenyl) hexafluoropropane (developer)
11.3 parts by weight 4-benzyloxyphenylethyl caprate (decolorant) 41.6 parts by weight The above components were stirred with a magnetic stirrer at 50 ° C. for 1 hour to obtain thermochromic compound 2.

Comparative Example 3
A black ink composition was obtained in the same manner as in Comparative Example 1 except that the thermochromic compound 1 of Comparative Example 1 was changed to the following thermochromic compound 3.
(Thermochromic compound 3)
2- (2-Chloroanilino) -6-di-n-butylaminofluorane (black leuco dye)
9.0 parts by weight 1,1-bis (4′-hydroxyphenyl) n-decane (developer)
9.0 parts by weight 1,1-bis (4′-hydroxyphenyl) hexafluoropropane (developer)
15.0 parts by weight 4-benzyloxyphenylethyl caprate (decolorant) 33.5 parts by weight The above components were stirred with a magnetic stirrer at 50 ° C. for 1 hour to obtain thermochromic compound 3.

Comparative Example 4
80 parts by weight of the base ink composition 1 and 20 parts by weight of the microcapsules 28 were dispersed with a magnetic stirrer to obtain a black ink composition.

The following tests were performed on the ink compositions of these Examples and Comparative Examples. The results are shown in Table 1.
Measurement of handwriting density The ink compositions obtained in Examples and Comparative Examples were filled in writing instruments (water gel ballpoint pen BLN25 (ball diameter 0.5 mm), product name: Engel) manufactured by Pentel Co., Ltd.), and fine paper (JIS P3201) On a writing paper A), a straight line of 5 cm was juxtaposed within a width of 1.5 cm, and a straight line was written with no gap, and the Y value was measured with a color computer.

Erasability test For each specimen used in the above-mentioned writing concentration measurement, the writing surface is rubbed by reciprocating 10 kg at a 90 ° angle with a load of 2 kg at the crown of the rear end of the Pentel Lorry BPC47A, immediately after (within 1 minute) Then, Y was measured on the rubbing portion with a color computer. The Y value of fine paper was 83.4%.

Decoloration maintenance state confirmation test For each specimen subjected to the erasability test, Y was measured with a color computer at the rubbing portion after 24 hours had elapsed after the erasability test.

The ink compositions of Examples 1 to 27 have a high handwriting density and are good compared to Comparative Example 1 using heat-erasable microcapsules.
The ink compositions of Examples 2 to 27 use a substance that does not easily evaporate and has a boiling point of 250 ° C. or higher, or a solid having an ester group, a ketone group, an ether group, or an aliphatic hydroxyl group. Later handwriting has reduced recurrence color.
Further, Examples 4-5, 7, 9-27, in which the solid having an ester group, a ketone group, an ether group, and an aliphatic hydroxyl group is amorphous, have an improved recurrence color prevention effect.
In Examples 6, 8, and 12 to 27, in which the average particle diameter of the microcapsules is 1 to 10 μm, the microcapsules are easily broken and the decoloring effect is high. In addition, the microcapsules at the time of ejection in the form of a ballpoint pen are not easily broken, and the handwriting density does not decrease.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
The present application includes a Japanese patent application filed on October 31, 2011 (Japanese Patent Application No. 2011-239827), a Japanese patent application filed on August 29, 2012 (Japanese Patent Application No. 2012-189322), and September 28, 2012. It is based on the Japanese patent application (Japanese Patent Application No. 2012-217192) of the application, and the content is taken in here as a reference.

  The ink composition of the present invention has a sufficiently thick handwriting written thereby, and can be erased by rubbing, and there is no reappearance of the erased handwriting, and it can be used for ink etc. in a ballpoint pen or the like. .

Claims (5)

A microcapsule containing at least a liquid material of a substance having at least one or two or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group, a leuco dye, a developer, and an ink liquid An erasable ink composition containing at least a medium , wherein the leuco dye and the developer are each dissolved directly in the ink liquid medium or dispersed as a pigment . The erasable ink composition according to claim 1, wherein the liquid material has a boiling point of 250 ° C. or higher. The erasable ink composition according to claim 1, wherein the liquid is a solid solution having one or more functional groups selected from an ester group, a ketone group, an ether group and an aliphatic hydroxyl group. The erasable ink composition according to claim 3, wherein the solid having one or more functional groups selected from the ester group, ketone group, ether group and aliphatic hydroxyl group is amorphous. The erasable ink composition according to any one of claims 1 to 4, wherein the average particle size of the microcapsules is 1 to 10 µm.