JP2008214557A - Encapsulated material and ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an encapsulated material for providing a liquid composition having an excellent dispersion stability and discharge stability and an excellent color development and light resistance of printed image and an ink composition using the encapsulated material. <P>SOLUTION: The encapsulated material is obtained by coating a photochromic substance having an electric charge on the surface with a wall material consisting essentially of a polymer. The polymer has (A) a repeating structural unit derived from (an ionic polymerizable surfactant A having an electric charge opposite to an electric charge on the surface of the photochromic substance) and/or (an ionic monomer having an electric charge opposite to an electric charge on the surface of the photochromic substance) and (B) a repeating structural unit derived from (an ionic polymerizable surfactant B having an electric charge identical or opposite to an electric charge on the surface of the photochromic substance). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an encapsulated material useful as a photochromic substance used by being added to a liquid composition such as an ink composition, and an ink composition using the encapsulated material.

  Conventionally, a photochromic substance whose color is changed by light is used as a coloring material of an ink composition. The ink composition containing the photochromic substance has a high color density of the printed image and excellent color developability, and also has excellent light resistance of the printed image, and maintains the color density at the initial stage of printing for a long period of time. Is required.

  As a method for improving the light resistance of a printed image, a method of encapsulating a photochromic substance in a fine capsule to form an encapsulated product is known, and various ink compositions containing the encapsulated product have been proposed. For example, Patent Document 1 discloses an ink composition containing a solvent, a vehicle, a microencapsulated photochromic material, and a microencapsulated fragrance. Patent Document 2 discloses a water-based ink composition in which a photochromic compound solution encapsulated in microcapsules is used as a coloring material and an aqueous emulsion resin is used as a vehicle. Patent Document 3 discloses a liquid composition containing a photochromic material obtained by dissolving a photochromic compound selected from a spirooxazine derivative or a spiropyran derivative in a styrene-based oligomer, and a resin. The encapsulated products of the photochromic substances described in Patent Documents 1 to 3 are all produced by a conventionally known encapsulation method such as a phase separation method, an interfacial polymerization method, an in situ polymerization method or the like.

  However, an ink composition containing a photochromic substance encapsulated by a conventional encapsulation method has an effect of improving the light resistance of a printed image as compared with an ink composition containing a non-encapsulated photochromic substance. On the other hand, there was a problem that the color developability deteriorated. In addition, the conventional ink composition containing an encapsulated photochromic substance has a problem that the photochromic substance tends to aggregate and is likely to be unstable when stored for a long period of time. When used in the above, there are problems such as inferior ejection stability (characteristic that the ink is stably ejected in a certain direction from the ink jet recording head) and clogging at the ink jet nozzle.

Japanese Patent Laid-Open No. 2-110173 Japanese Patent Laid-Open No. 2-110174 JP 2006-22202 A

  The present invention has been made in view of the above problems, and the object thereof is a liquid composition having excellent dispersion stability and ejection stability, and excellent color development and light resistance of printed images. And an ink composition using the encapsulated product.

  As a result of intensive studies, the present inventors have found that an encapsulated material in which a photochromic substance is coated with a wall material mainly composed of a polymer having a specific composition can achieve the above object. This invention is made | formed based on such knowledge, The technical structure is as follows.

[1] An encapsulated material in which a photochromic substance having a charge on its surface is coated with a wall material mainly composed of a polymer, wherein the polymer comprises a repeating structural unit of the following (A) and a repeating structure of the following (B) Encapsulate having at least units.
(A) derived from “an ionic polymerizable surfactant A having a charge opposite to the charge on the surface of the photochromic substance” and / or “an ionic monomer having a charge opposite to the charge on the surface of the photochromic substance”. Repeated structural units.
(B) A repeating structural unit derived from “ionic polymerizable surfactant B having the same or opposite charge as the surface charge of the photochromic substance”.

  [2] To the aqueous dispersion of the photochromic substance, the ionic polymerizable surfactant A and / or the ionic monomer and the ionic polymerizable surfactant B were sequentially added and mixed in this order. Thereafter, the encapsulated product according to the above [1], which was produced by adding a polymerization initiator and polymerizing them.

  [3] The polymer comprises a repeating structural unit derived from a hydrophobic monomer, a repeating structural unit derived from a crosslinkable monomer, and a repeating structural unit derived from a compound represented by the following general formula (1). The encapsulated product according to the above [1] or [2], further comprising one or more selected from the group.

［ただし、Ｒ¹は水素原子又はメチル基を表す。Ｒ²はｔ−ブチル基、脂環式炭化水素基、芳香族炭化水素基、又はヘテロ環基を表す。ｍは０〜３、ｎは０又は１の整数を表す。］

[However, R ¹ represents a hydrogen atom or a methyl group. R ² represents a t-butyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group. m represents an integer of 0 to 3, and n represents an integer of 0 or 1. ]

[4] An ink composition containing the encapsulated product according to any one of [1] to [3].
[5] An ink for ink jet recording containing the encapsulated product according to any one of [1] to [3], a water-soluble organic solvent, and water.

According to the encapsulated product of the present invention, it is excellent in dispersion stability and ejection stability, hardly causes inconvenience such as clogging of an inkjet nozzle, is excellent in inkjet reliability, and is excellent in color development and light resistance of a printed image. Liquid compositions such as ink compositions can be provided.
In addition, according to the ink composition (inkjet recording ink) of the present invention using the encapsulated product of the present invention, since the encapsulated product is excellent in dispersion stability and ejection stability, various printing methods such as an inkjet method are available. Can be suitably used, and a printed image having excellent color development and light resistance can be provided.

Hereinafter, first, the encapsulated product of the present invention will be described.
The encapsulated material of the present invention is obtained by coating the periphery of a core material with a wall material mainly composed of a polymer. The core material is a photochromic material having a charge on the surface, and the wall material contains a polymer. The main component.

  The wall material is substantially composed of a polymer, and the content of the polymer in the wall material is 60% by weight or more. The wall material can contain a UV absorber, a light stabilizer, an antioxidant, a flame retardant, a plasticizer, a wax, and the like as necessary in addition to the polymer.

The polymer which is the main component of the wall material contains at least the following two types of repeating structural units (A) and (B).
Repeating structural unit (A): “ionic polymerizable surfactant A having a charge opposite to the charge of the surface of the photochromic material having a charge on the surface” and / or “the surface of the photochromic material having a charge on the surface” A repeating structural unit derived from an “ionic monomer having a charge opposite to the charge”.
Repeating structural unit (B): A repeating structural unit derived from “an ionic polymerizable surfactant B having the same or opposite charge as the charge on the surface of the photochromic substance having a charge on the surface”.

  The wall material covering the photochromic substance contains the above repeating structural units (A) and (B), so that the photochromic substance (capsule) can be obtained without impairing the color developability and light resistance in the printed image originally possessed by the photochromic substance. It is possible to improve the dispersion stability and ejection stability in the aqueous solvent.

The ionic polymerizable surfactant A preferably has an ionic group having a charge opposite to the charge on the surface of the photochromic substance, a hydrophobic group, and a polymerizable group.
The ionic monomer preferably has an ionic group having a charge opposite to the charge on the surface of the photochromic substance, a hydrophobic group, and a polymerizable group.
The ionic polymerizable surfactant B preferably has an ionic group having the same or opposite charge as the surface charge of the photochromic material, a hydrophobic group, and a polymerizable group.

The amount of the repeating structural unit (A) in the polymer is preferably the number of moles that provides a charge amount equivalent to the charge amount on the surface of the conductive substance.
The amount of the repeating structural unit (B) in the polymer is preferably a mole number corresponding to 0.5 to 1.5 times the total charge amount of the repeating structural unit (A) contained in the polymer. .

  From the viewpoint of ensuring that the encapsulated product of the present invention reliably exhibits its effects (which can provide an ink composition excellent in dispersion stability, ejection stability, and color development and light resistance of a printed image). It is preferable to manufacture by the following procedure. That is, the encapsulated product of the present invention is prepared by adding the ionic polymerizable surfactant A and / or the ionic monomer and the ionic polymerizable surfactant B to an aqueous dispersion of a photochromic substance having a charge on the surface. Are preferably added and mixed in this order, and then polymerized by adding a polymerization initiator.

  In the above-mentioned encapsulated product manufacturing method, the ionic polymerizable surfactant A and / or ionic monomer is disposed so as to surround the photochromic substance (core substance), and the ionic polymerizable surfactant is further provided. The ionic polymerizable surfactant B is arranged so as to surround the agent A and / or the ionic monomer, and as a result, the arrangement of these monomer components is highly controlled before the polymerization is started. Admicells are formed in the aqueous solvent. Then, the polymerization reaction is started in a state where the admicelle is maintained, and the monomer is converted into a polymer, whereby the structure is controlled with high accuracy, and an encapsulated product that reliably exhibits the above-described effects is obtained.

  FIG. 1 is a schematic diagram showing an example of the above-mentioned admicelle. A core substance (photochromic substance) 1 shown in FIG. 1 has an anionic group 14 such as a hydrophilic group on its surface and is dispersed in an aqueous solvent containing water as a main component. A cationic polymerizable surfactant 2 having a cationic group 11, a hydrophobic group 12 and a polymerizable group 13 (an ionic polymerizable interface having a charge opposite to the charge on the surface of the photochromic substance) The activator A) is adsorbed with a strong ionic bond with its cationic group 11 directed towards the anionic group 14. Then, the anionic polymerizable surfactant 3 (photochromic) having an anionic group 14 ′, a hydrophobic group 12 ′ and a polymerizable group 13 ′ with respect to the cationic polymerizable surfactant 2 thus adsorbed on the core substance 1. The ionic polymerizable surfactant B) having the same kind or opposite charge as the surface charge of the substance causes the hydrophobic interaction between the hydrophobic groups 12, 12 ′ and the polymerizable groups 13, 13 ′. It is arranged on the outermost shell of the admicel so as to face each other. At this time, the anionic group 14 ′ of the anionic polymerizable surfactant 3 is oriented in the direction away from the core material 1 (the direction in which the aqueous solvent is present).

  Then, by adding a polymerization initiator to an aqueous solvent in which admicelle is present as shown in FIG. 1 and polymerizing the monomer present around the core material 1, the monomer is converted into a polymer, as shown in FIG. In addition, the encapsulated material 100 in which the core material 1 is coated with the wall material 60 whose main component is a polymer is obtained. Since the anionic group 14 ′ derived from the anionic polymerizable surfactant 3 is present on the outer surface of the wall material 60 (the surface opposite to the surface facing the core material 1), the encapsulated product 100 is Good dispersion stability in an aqueous solvent.

  When an ionic monomer is used instead of the ionic polymerizable surfactant A, or when an ionic monomer is used in combination with the ionic polymerizable surfactant A, or each of the above monomers (ionic polymerizable surfactant A) In addition, in addition to the ionic monomer and the ionic polymerizable surfactant B), other monomers described below that can be copolymerized therewith, the encapsulated product is produced through the formation of the admicelle.

  In addition, as a method for encapsulating the core substance, there are a phase inversion emulsification method and an acid precipitation method. However, in these conventional encapsulation methods, the encapsulated product obtained by the encapsulation method through the formation of the above admicelle is used. Only encapsulated materials with poor dispersion stability can be obtained. The reason for this is not clear, but in the phase inversion emulsification method or acid precipitation method, since the polymer prepared in advance is used as the wall material for coating the core material, the coating state of the wall material on the core material is not complete (core This is probably because the substance is not completely covered by the wall material. In the phase inversion emulsification method, since an organic solvent is used in the encapsulation process, the organic solvent may remain in the encapsulated product obtained by the phase inversion emulsification method, and the encapsulated product is added. There may be a problem in the stability of the performance of the ink composition. In particular, when the encapsulated product obtained by the phase inversion emulsification method is used for ink for inkjet recording, it may adversely affect the dispersion stability, ejection stability, quality of printed image, etc. May cause inconvenience such as deterioration of the plastic member. On the other hand, the encapsulated product (preferred encapsulated product of the present invention) obtained by the encapsulation method for forming the above admicelle does not use an organic solvent in its production, has a stable performance, and is a plastic. It does not cause deterioration of the member.

  In the encapsulated material of the present invention, the structure of the wall material may be a single layer or a multilayer. When manufacturing an encapsulated material having a wall material having a multilayer structure, taking an encapsulated material having a wall material having a two-layer structure as an example, first, the core material (photochromic material) is formed into a wall material (by the same method as described above). In this section, the encapsulated material coated with the first wall material is manufactured. Next, the aqueous dispersion in which the encapsulated material is dispersed has an ionic polymerizable property having a charge opposite to the charge on the outer surface of the first wall material (the surface opposite to the surface facing the core material). After adding and mixing “Surfactant C” and / or “ionic monomer having a charge opposite to the charge on the outer surface of the first wall material”, the same or opposite to the charge on the surface of the first wall material Add and mix ionic polymerizable surfactant D "having the following charge. Next, a polymerization initiator is added to the aqueous dispersion to polymerize the added components to form a second wall material. In this way, an encapsulated material in which the photochromic substance is coated with the two-layer wall material composed of the first wall material and the second wall material is obtained. The ionic polymerizable surfactant C may be the same as the ionic polymerizable surfactant A, and the ionic polymerizable surfactant D may be the ionic polymerizable surfactant D. The thing similar to the agent B can be used.

  An encapsulated material having a wall material having a multilayer structure of three or more layers can be produced by sequentially forming the wall material toward the outside of the core material according to the above method.

  The volume average particle diameter of the encapsulated product of the present invention may be appropriately adjusted depending on the use of the encapsulated product, and is not particularly limited. For example, when the encapsulated material is added to the ink composition, the thickness is preferably 20 to 600 nm, and when the encapsulated material is added to the ink for inkjet recording containing a water-soluble organic solvent, the thickness is preferably 30 to 200 nm. The volume average particle diameter of the encapsulated product can be controlled by appropriately adjusting the addition amount of various polymerization components (monomers), the stirring state of the reaction mixture, and the like.

  The film-forming property of the encapsulated product of the present invention and the strength, chemical resistance, water resistance, light resistance, weather resistance, optical properties, other physical properties and chemical properties of the wall material are the same as those of the polymer that is the main component of the wall material. By appropriately controlling the composition, the structure, etc., it is possible to make it suitable for the use of the encapsulated product. In particular, the fixing property of the encapsulated material to various substrates (paper, plastic, metal, etc.) and the abrasion resistance of the printed portion (ink-attached portion) by the ink composition to which the encapsulated material is added are the main components of the wall material. It can be controlled by the glass transition temperature (Tg) of the polymer.

  Generally, in polymer solids, especially amorphous polymer solids, when the temperature is raised from a low temperature to a high temperature, a state where a large amount of deformation occurs with a small force from a state where a very large force is required for slight deformation (glass state). The temperature at which this phenomenon occurs is called the glass transition temperature (or glass transition point). Generally, in the differential heat curve obtained by temperature rise measurement with a differential scanning calorimeter, the intersection of the base line when the tangent line is drawn from the bottom of the endothermic peak toward the end point of the endotherm. The temperature is defined as the glass transition temperature (Tg in the present specification follows this definition). In addition, it is known that other physical properties such as elastic modulus, specific heat, and refractive index change abruptly at the glass transition temperature, and it is known that the glass transition temperature is also determined by measuring these physical properties. ing. Further, the glass transition temperature can be calculated by the following Fox equation from the weight fraction of the monomer used in synthesizing the copolymer and the glass transition point of the homopolymer obtained by homopolymerizing the monomer. (In the present invention, the glass transition temperature obtained by the Fox equation was used.)

（上記式中、Ｔｇ_[p]は得られるポリマーのガラス転移温度、ｉは種類の異なるモノマーごとに付した番号、Ｔｇ_[hp]iは重合に用いるモノマーｉのホモポリマーのガラス転移温度、ｘiは重合するモノマーの重量総計に対するモノマーｉの重量分率を表す。）

(In the above formula, Tg _[p] is the glass transition temperature of the polymer obtained, i is the number assigned to each different type of monomer, Tg _{[hp] i} is the glass transition temperature of the homopolymer of monomer i used for polymerization, xi Represents the weight fraction of monomer i with respect to the total weight of monomers to be polymerized.)

  That is, when the temperature environment in which the encapsulated material of the present invention is placed is higher than the glass transition temperature of the polymer constituting the wall material of the encapsulated material, the polymer is in a state where large deformation occurs with a small force. It melts when it reaches the melting point. At this time, if another encapsulated product is present in the vicinity, the encapsulated products are fused to form a film. In addition, even when the ambient temperature does not reach the melting point, when the encapsulated materials come into contact with each other with a strong force, there is a condition that enables the polymers covering each encapsulated material to be entangled with each other. If arranged, the polymers covering the encapsulated material may be fused together.

  When the ink composition containing the encapsulated material of the present invention is applied to various substrates using an ink jet printer or the like, the encapsulated material is favorably formed on a substrate such as printing paper at room temperature, and the encapsulated material ( In order to obtain good results with respect to the fixing property and rubbing resistance of the core material) to the substrate, the Tg of the polymer as the main component of the wall material is preferably 30 ° C. or less, more preferably 15 ° C. or less, and still more preferably Is 10 ° C. or lower. However, if the Tg of the polymer is lower than −20 ° C., the solvent resistance of the encapsulated product may be lowered, and an undesirable result may be produced in dispersion stability or the like.

  Hereinafter, various raw materials used for production of the encapsulated product of the present invention will be described.

[Photochromic material]
The photochromic substance that is the core substance of the encapsulated product of the present invention is not particularly limited as long as it is a substance that changes color by light. Examples thereof include stilbene derivatives, spiropyrans, spirooxazines, diarylethenes, fulgides, cyclophanes, chalcone derivatives, and the like, or mixtures thereof.

  As a photochromic substance, a substance that does not originally have a charge on the surface, or a substance that has a charge on the surface but has a very weak charge, can be charged using a physical action such as a chemical reaction or adsorption. It is also possible to use a substance (surface-treated photochromic substance) into which a functional group having a chemical substance or a chemical substance is introduced. The production of the surface-treated photochromic material is, for example, “surface treatment of pigment particles with a hydrophilic group-imparting agent” described in [0036] to [0056] of JP-A-2005-97476 related to the earlier application of the present applicant. Can be carried out by a method according to.

  What is necessary is just to select the average particle diameter of the primary particle of a photochromic substance suitably according to the use etc. of an encapsulated material. For example, when an encapsulated product is added to the ink composition, the average particle size of the primary particles of the photochromic substance is preferably 10 from the viewpoint of improving the reliability (particularly ejection stability and dispersion stability) of the ink composition. It is -600 nm, More preferably, it is 10-400 nm. In addition, the average particle diameter here means the measured value of the laser light scattering method.

[Ionic polymerizable surfactant A]
The ionic polymerizable surfactant A is a polymerization component of a polymer that is a main component of a wall material that coats the core material (photochromic material), and has an ionic group having a charge opposite to the charge on the surface of the core material, It has a hydrophobic group and a polymerizable group.

  Examples of the hydrophobic group include a linear alkyl group having 8 to 16 carbon atoms, a branched alkyl group having 8 to 16 carbon atoms, and an alkylbenzene (alkylphenyl group) having both an alkyl group and an aryl group in the molecule. Or an alkylnaphthalene (an alkylnaphthyl group), or a polypropylene oxide group. It can also have both an alkyl group and an aryl group in the molecule.

  The polymerizable group is preferably an unsaturated hydrocarbon group capable of radical polymerization, specifically, from the group consisting of a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a propenyl group, a vinylidene group, and a vinylene group. Preferred is a selected group. Among these, an allyl group, a methacryloyl group, and an acryloyl group are particularly preferable.

  Examples of the ionic group include a cationic group and an anionic group. The ionic polymerizable surfactant having a cationic group as the ionic group is referred to as a “cationic polymerizable surfactant”. The ionic polymerizable surfactant having an anionic group as the ionic group is referred to as “anionic polymerizable surfactant”. In the present invention, the ionic polymerizable surfactant A having an ionic group having a charge opposite to the charge on the surface of the core material is adsorbed on the surface of the core material by utilizing electrostatic interaction. As the ionic polymerizable surfactant A, either a cationic polymerizable surfactant or an anionic polymerizable surfactant is used depending on the charge of the core material surface.

As the cationic polymerizable surfactant, for example, the general formula _{R [4- (l + m +} n)] R 1 l R 2 m R 3 n N + · X - be exemplified represented by compound (In the above general formula, R is a polymerizable group, R ¹ , R ² and R ³ are each an alkyl group having 8 to 16 carbon atoms and an aryl group such as a phenyl group and a phenylene group, and X ⁻ is Cl ⁻ , Br ⁻ , I ⁻ , CH ₃ OSO ₃ ⁻ , C ₂ H ₅ OSO ₃ ^— , and l 1, m 2 and n are each 1 or 0). Here, as a polymeric group, the same thing as what was mentioned above can be mentioned.

Specific examples of the cationic polymerizable surfactant include dimethylaminoethyl octyl chloride salt, dimethylaminoethyl cetyl chloride methacrylate, dimethylaminoethyl decyl chloride methacrylate, dimethylaminoethyl dodecyl chloride methacrylate, And dimethylaminoethyl tetradecyl chloride salt of methacrylic acid.
The cationic polymerizable surfactants exemplified above can be used in the present invention alone or as a mixture of two or more.

  Specific examples of the anionic polymerizable surfactant include an anionic allyl as described in JP-B-49-46291, JP-B-1-24142, or JP-A-62-104802. Derivatives, anionic propenyl derivatives as described in JP-A-62-221431, anionic properties as described in JP-A-62-34947 or JP-A-55-11525 Acrylic acid derivatives, anionic itaconic acid derivatives as described in JP-B-46-34898 or JP-A-51-30284, and the like can be mentioned.

  Examples of the anionic polymerizable surfactant used in the present invention include the following general formula (31):

［式中、Ｒ²¹及びＲ³¹は、それぞれ独立して、水素原子又は炭素数１〜１２の炭化水素基であり、Ｚ¹は、炭素−炭素単結合又は式：
−ＣＨ₂−Ｏ−ＣＨ₂−
で表される基であり、ｍは２〜２０の整数であり、Ｘは式−ＳＯ₃Ｍ¹で表される基であり、Ｍ¹はアルカリ金属、アンモニウム塩、又はアルカノールアミンである。]
で表される化合物、又は、例えば、下記一般式（３２）：

[Wherein, R ²¹ and R ³¹ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and Z ¹ represents a carbon-carbon single bond or a formula:
—CH ₂ —O—CH ₂ —
M is an integer of 2 to 20, X is a group represented by the formula —SO ₃ M ¹ , and M ¹ is an alkali metal, an ammonium salt, or an alkanolamine. ]
Or a compound represented by the following general formula (32):

［式中、Ｒ²²及びＲ³²は、それぞれ独立して、水素原子又は炭素数１〜１２の炭化水素基であり、Ｄは、炭素−炭素単結合又は式：
−ＣＨ₂−Ｏ−ＣＨ₂−
で表される基であり、ｎは２〜２０の整数であり、Ｙは式−ＳＯ₃Ｍ²で表される基であり、Ｍ²はアルカリ金属、アンモニウム塩、又はアルカノールアミンである。］
で表される化合物が好ましい。

[Wherein, R ²² and R ³² each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and D represents a carbon-carbon single bond or a formula:
—CH ₂ —O—CH ₂ —
N is an integer of 2 to 20, Y is a group represented by the formula —SO ₃ M ² , and M ² is an alkali metal, an ammonium salt, or an alkanolamine. ]
The compound represented by these is preferable.

  Examples of the compound represented by the general formula (31) (anionic polymerizable surfactant) include compounds described in JP-A-5-320276 or JP-A-10-316909. . By appropriately adjusting the value of m in the general formula (31), the hydrophilicity of the surface of the encapsulated product obtained by encapsulating the core substance can be adjusted. Preferred polymerizable surfactants represented by the general formula (31) include compounds represented by the following general formula (310), and more specifically, the following formulas (31a) to (31d). ) Can be mentioned.

［式中、Ｒ³¹、ｍ、及びＭ¹は一般式（３１）で表される化合物と同様である。］

[Wherein, R ³¹ , m and M ¹ are the same as those in the compound represented by the general formula (31). ]

A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said general formula (310). For example, Adeka Soap SE-10N manufactured by Asahi Denka Kogyo Co., Ltd. is a compound represented by the general formula (310), in which M ¹ is NH ₄ , R ³¹ is C ₉ H ₁₉ , and m = 10. It is. Adeka Soap SE-20N manufactured by Asahi Denka Kogyo Co., Ltd. is a compound represented by the general formula (310) in which M ¹ is NH ₄ , R ³¹ is C ₉ H ₁₉ , and m = 20. .

  Examples of the anionic polymerizable surfactant used in the present invention include the following general formula (33):

［式中、ｐは９又は１１であり、ｑは２〜２０の整数であり、Ａは−ＳＯ₃Ｍ³で表わされる基であり、Ｍ³はアルカリ金属、アンモニウム塩又はアルカノールアミンである。］
で表される化合物が好ましい。上記一般式（３３）で表される好ましいアニオン性重合性界面活性剤としては、以下の化合物を挙げることができる。

[In the formula, p is 9 or 11, q is an integer of 2 to 20, A is a group represented by —SO ₃ M ³ , and M ³ is an alkali metal, an ammonium salt or an alkanolamine. ]
The compound represented by these is preferable. Preferred examples of the anionic polymerizable surfactant represented by the general formula (33) include the following compounds.

［式中、ｒは９又は１１、ｓは５又は１０である。］

[Wherein, r is 9 or 11, and s is 5 or 10. ]

  A commercially available product can also be used as the compound of [Chemical Formula 11] (anionic polymerizable surfactant). Examples of commercially available products include Aqualon KH series (Aqualon KH-5 and Aqualon KH-10) (above, trade names) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and the like. Aqualon KH-5 is a mixture of the compound of the above [Chemical Formula 11] wherein r is 9 and s is 5 and the compound where r is 11 and s is 5. Aqualon KH-10 is a mixture of the compound represented by [Chemical Formula 11] wherein r is 9 and s is 10 and the compound where r is 11 and s is 10.

  Moreover, as said anionic polymerizable surfactant used for this invention, the compound represented by following General formula (34) is preferable.

[式中、Ｒは炭素数８〜１５のアルキル基であり、ｎは２〜２０の整数であり、Ｘは−ＳＯ₃Ｂで表わされる基であり、Ｂはアルカリ金属、アンモニウム塩又はアルカノールアミンである。]

[Wherein, R is an alkyl group having 8 to 15 carbon atoms, n is an integer of 2 to 20, X is a group represented by —SO ₃ B, and B is an alkali metal, an ammonium salt or an alkanolamine] It is. ]

A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said General formula (34). As a commercial item, Asahi Denka Kogyo Co., Ltd. Adeka rear soap SR series (Adeka rear soap SR-10, SR-20, SR-1025) (above, a brand name) etc. can be mentioned, for example. The ADEKA rear soap SR series is a compound in which B is NH ₄ in the general formula (34), SR-10 is n = 10, and SR-20 is n = 20.

  Moreover, as said anionic polymerizable surfactant used for this invention, the compound represented by the following general formula (A) can also be used.

［上記式（Ａ）中、Ｒ⁴は水素原子又は炭素数１から１２の炭化水素基を表し、ｌは２〜２０の数を表し、Ｍ⁴はアルカリ金属、アンモニウム塩、又はアルカノールアミンを表す。］

[In the above formula (A), R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, l represents a number of 2 to 20, and M ⁴ represents an alkali metal, an ammonium salt, or an alkanolamine. . ]

  A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said general formula (A). As a commercial item, the Dai-Ichi Kogyo Seiyaku Co., Ltd. product Aqualon HS series (Aquaron HS-10, HS-20, and HS-1025) (above, a brand name) is mentioned, for example.

  Examples of the anionic polymerizable surfactant used in the present invention include sodium alkylallylsulfosuccinate represented by the following general formula (35).

  A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said General formula (35). As a commercial item, Elyoinol JS-2 of Sanyo Chemical Industries Ltd. can be mentioned, for example, In the said General formula (35), it is a compound represented by m = 12.

  Examples of the anionic polymerizable surfactant used in the present invention include methacryloyloxypolyoxyalkylene sulfate sodium salt represented by the following general formula (36). In the following general formula (36), n is 1-20.

  A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said General formula (36). As a commercial item, the Eleminol RS-30 of Sanyo Chemical Industries Ltd. can be mentioned, for example, In the said General formula (36), it is a compound represented by n = 9.

  Moreover, as said anionic polymerizable surfactant used for this invention, the compound represented by following General formula (37) can be used, for example.

[式中、Ｒ₁は水素原子又はメチル基を表し、Ｒ₂及びＲ₄は水素原子又はアルキル基で各々同一か異なっていてもよく、Ｒ₃及びＲ₅は水素原子又はアルキル基、ベンジル基、スチレン基で各々同一か異なっていてもよく、Ｘはアルカリ金属原子、アルカリ土類金属原子、アンモニウム又はアミンカチオンを表し、ｍは０又は１以上の整数を表し、ｎは１以上の整数を表す。]

[Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₄ may be a hydrogen atom or an alkyl group, which may be the same or different, and R ₃ and R ₅ represent a hydrogen atom, an alkyl group, or a benzyl group. , Each styrene group may be the same or different, X represents an alkali metal atom, an alkaline earth metal atom, ammonium or an amine cation, m represents 0 or an integer of 1 or more, and n represents an integer of 1 or more. To express. ]

A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the said General formula (37). Examples of commercially available products include Antox MS-60 manufactured by Nippon Emulsifier Co., Ltd. In the general formula (37), R ₁ is a methyl group, R ₂ , R ₃ , R ₄ and R ₅ are hydrogen atoms. Alternatively, an alkyl group, a compound in which m and n are positive integers, and X is ammonium are equivalent.
The anionic polymerizable surfactants exemplified above can be used alone or as a mixture of two or more.

[Ionic polymerizable surfactant B]
The ionic polymerizable surfactant B is a polymerization component of a polymer that is a main component of the wall material that coats the core material, an ionic group having the same or opposite charge as the surface charge of the core material, and hydrophobicity. Group and a polymerizable group. As the ionic group, the hydrophobic group, and the polymerizable group, the same ones as described in the above section [Ionic polymerizable surfactant A] can be used. As the cationic surfactant B, the same surfactants as the cationic polymerizable surfactant and the anionic polymerizable surfactant described in the section of [Ionic polymerizable surfactant A] can be used.

[Ionic monomer]
The ionic monomer is a polymerized component of the polymer that is the main component of the wall material that covers the core material, and includes an ionic group having a charge opposite to the charge on the surface of the core material, a hydrophobic group, and a polymerizable group. It is water-soluble.
The hydrophobic group is preferably one or two or more selected from the group consisting of an alkyl group having 1 to 7 carbon atoms and an aryl group such as a phenyl group and a phenylene group. It can also have both groups.
As the polymerizable group, the same groups as those described in the section of [Ionic polymerizable surfactant A] can be used.
Examples of the ionic group include a cationic group and an anionic group. An ionic monomer having a cationic group as the ionic group is referred to as a “cationic water-soluble monomer”, and the ionic group includes an anion. The ionic monomer having an ionic group is referred to as “anionic water-soluble monomer”. In the present invention, any of a cationic monomer and an anionic monomer may be used as the ionic monomer, and any one may be appropriately selected according to the use of the encapsulated product.

The cationic group (ionic group) is preferably a cationic group selected from the group consisting of a primary ammonium cation, a secondary ammonium cation, a tertiary ammonium cation, and a quaternary ammonium cation. The primary ammonium cation is a monoalkylammonium cation (RNH ₃ ⁺ ), the secondary ammonium cation is a dialkylammonium cation (R ₂ NH ₂ ⁺ ), and the tertiary ammonium cation is a trialkylammonium cation (R ₃ NH). ⁺ ) And the like, and examples of the quaternary ammonium cation include (R ₄ N ⁺ ). Here, R is a hydrophobic group, and examples thereof include the following. Examples of the counter anion of the cationic group include Cl ⁻ , Br ⁻ , I ⁻ , CH ₃ OSO ₃ ⁻ , C ₂ H ₅ OSO ₃ ^{— and the} like.

Examples of the anionic group (ionic group) include a sulfonic acid group (—SO ₃ ⁻ ), a sulfinic acid group (—SO ₂ ⁻ ), a sulfate ester group (—OSO ₃ ⁻ ), a carboxyl group (—COO ⁻ ), Phosphoric acid groups (= O ₂ PO (O ⁻ ), —OPO (O ⁻ ) ₂ ), phosphorous acid groups (═O ₂ PO ⁻ , —OP (O ⁻ ) ₂ ), phosphonic acid groups (—PO ₂ ( ^{O -), - PO (O} -) 2), sulfinic acid ester group (-OSO ₂ ^-), and phosphate ester group, which is used in the form of a salt as shown below. Specifically, sulfonate (—SO ₃ M), sulfinate (—SO ₂ M), sulfate ester salt (—OSO ₃ M), carboxylate (—COOM), phosphate (═O ₂₎ PO (OM), - OPO ( OM) 2), phosphite _{(= O 2 POM, -OP (} OM) 2), phosphonate _{(-PO 2 (OM), -} PO (OM) 2), A sulfinic acid ester salt (-OSO ₂ M) and a phosphoric acid ester salt can be suitably exemplified, and M is hydrogen, an alkali metal, an alkaline earth metal, NH ₄ , an amine, ethanolamine, or the like. .

  Preferred specific examples of the cationic water-soluble monomer (ionic monomer) used in the present invention include dimethylaminoethyl methyl chloride salt, dimethylaminoethyl benzyl methacrylate salt, methacryloyloxyethyl trimethylammonium chloride salt, diallyl Examples thereof include dimethylammonium chloride salt and 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride salt. A commercial item can also be used as said cationic water-soluble monomer, For example, Acryester DMC (Mitsubishi Rayon Co., Ltd.), Acryester DML60 (Mitsubishi Rayon Co., Ltd.), and C-1615 (Daiichi Kogyo Seiyaku) (Co., Ltd.)). The cationic water-soluble monomers exemplified above can be used alone or as a mixture of two or more.

  Preferable specific examples of the anionic water-soluble monomer (ionic monomer) used in the present invention include, for example, acrylic acid, methacrylic acid, crotonic acid, propylacrylic acid, isopropylacrylic acid, and the like as monomers having a carboxyl group. -Acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl phthalic acid, itaconic acid, fumaric acid, maleic acid and the like. Among these, acrylic acid and methacrylic acid are preferable. Examples of the monomer having a sulfonic acid group include 4-styrene sulfonic acid and its salt, vinyl sulfonic acid and its salt, sulfoethyl acrylate and its salt, sulfoethyl methacrylate and its salt, sulfoalkyl acrylate and its salt, sulfoalkyl Methacrylate and its salt, sulfopropyl acrylate and its salt, sulfopropyl methacrylate and its salt, sulfoaryl acrylate and its salt, sulfoaryl methacrylate and its salt, butylacrylamide sulfonic acid and its salt, 2-acrylamido-2-methylpropanesulfone Examples include acids and salts thereof. Examples of the monomer having a phosphone group include phosphoric acid group-containing (meth) acrylates such as phosphoethyl methacrylate. The anionic water-soluble monomers exemplified above can be used alone or as a mixture of two or more.

[Other monomers]
In addition to the repeating structural units (A) and (B) derived from the above-described monomers, the polymer constituting the wall material according to the present invention, if necessary, other repeating structural units derived from other monomers. Can be contained. Preferred other repeating structural units include “a repeating structural unit derived from a hydrophobic monomer”, “a repeating structural unit derived from a crosslinkable monomer”, and “derived from a compound represented by the above general formula (1)”. Recurring structural units ”, and one or more of these can be used.
Hereinafter, monomers constituting these repeating structural units will be described.

[Hydrophobic monomer]
Repeating structural units derived from hydrophobic monomers are used to control the film-forming properties of encapsulated materials, the strength of wall materials, chemical resistance, water resistance, light resistance, weather resistance, optical properties, and other physical and chemical properties. Effective, especially solvent resistance of wall materials, fixability of encapsulated materials (photochromic materials) to various substrates, printed portion (ink adhering portions) with ink composition to which encapsulated materials are added, and abrasion resistance and water resistance It is effective for improving the property.

The hydrophobic monomer used in the present invention has at least a hydrophobic group and a polymerizable group in its structure, and the hydrophobic group includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic group. Examples thereof include those selected from the group of group hydrocarbon groups. Aliphatic hydrocarbon groups include methyl, ethyl, and propyl groups, and alicyclic hydrocarbon groups include cyclohexyl, dicyclopentenyl, dicyclopentanyl, and isobornyl groups. Examples of the hydrogen group include a benzyl group, a phenyl group, and a naphthyl group.
As the polymerizable group of the hydrophobic monomer, the same groups as those described in the above section [Ionic polymerizable surfactant A] can be used.

  Specific examples of the hydrophobic monomer include styrene derivatives such as styrene, methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, dichlorostyrene, t-butylstyrene, bromostyrene, and p-chloromethylstyrene; methyl acrylate, acrylic Ethyl isopropyl acrylate, n-butyl acrylate, butoxyethyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl acrylate, benzyl acrylate, acrylic acid Phenyl, phenoxyethyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, Cyclopentenyloxyethyl acrylate, tetrahydrofurfuryl acrylate, and isobornyl acrylate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxy polyethylene glycol acrylate Monofunctional acrylic acid esters such as nonylphenol EO adduct acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl diglycol acrylate, octoxypolyethylene glycol polypropylene glycol monoacrylate, methyl methacrylate, Ethyl tacrylate, isopropyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate , Stearyl methacrylate, isodecyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, methoxydiethylene glycol methacrylate, polypropylene glycol monomethacrylate, phenyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, cyclohexyl methacrylate, tetrahydro methacrylate Furfuryl, t-butylcyclo Monofunctional methacrylates such as hexyl methacrylate, behenyl methacrylate, dicyclopentanyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, butoxymethyl methacrylate, and isobornyl methacrylate, octoxy polyethylene glycol polypropylene glycol monomethacrylate, etc. Allyl compounds such as allylbenzene, allyl-3-cyclohexanepropionate, 1-allyl-3,4-dimethoxybenzene, allylphenoxyacetate, allylphenylacetate, allylcyclohexane, and polyvalent allyl carboxylate; fumaric acid, Unsaturated esters such as maleic acid and itaconic acid; radical polymerizable groups such as N-substituted maleimide and cyclic olefin Include monomers that is able to use these alone or in combination of two or more.

  What is necessary is just to adjust suitably the quantity of the "repeating structural unit induced | guided | derived from the hydrophobic monomer" in the polymer which comprises the wall material which concerns on this invention according to the use etc. of an encapsulated material.

[Crosslinking monomer]
By including a “repeating structural unit derived from a crosslinkable monomer” in the polymer constituting the wall material according to the present invention, a crosslinked structure is formed in the polymer, thereby improving the solvent resistance of the encapsulated product. be able to. When the solvent resistance of the encapsulated product is low, for example, when the encapsulated product is added to the ink composition and used, the solvent contained in the ink composition causes the polymer constituting the wall material of the encapsulated product to There is a risk of penetration into the interior, and as a result, the polymer may swell, deform, and the like, and the dispersion stability of the encapsulated product may decrease. By forming a cross-linked structure in the polymer constituting the wall material of the encapsulated material, the solvent resistance of the encapsulated material is improved, and thus the dispersion stability of the encapsulated material is improved in an ink composition in which a water-soluble organic solvent coexists. Performance, storage stability of the ink composition, and ejection stability of the ink composition from the inkjet nozzle can be further enhanced.
In addition, when the crosslinkable monomer is used in combination with the hydrophobic monomer, the mechanical strength and heat resistance of the polymer that is the main component of the wall material is increased by copolymerizing the hydrophobic monomer and the crosslinkable monomer. The form maintainability of the wall material is improved.

  The crosslinkable monomer used in the present invention includes a compound having two or more unsaturated hydrocarbon groups of at least one selected from vinyl group, allyl group, acryloyl group, methacryloyl group, propenyl group, vinylidene group, and vinylene group The thing which has is mentioned. Specific examples of the crosslinkable monomer include, for example, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, allyl acrylate, and bis (acryloxyethyl) hydroxyethyl isocyanurate. Bis (acryloxy neopentyl glycol) adipate, 1,3-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, 2-hydroxy-1 , 3-Diacryloxypropane, 2,2-bis [4- (acryloxy) phenyl] propane, 2,2- [4- (acryloxyethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy polyethoxy) phenyl] propane , Hydroxybivalic acid neopentyl glycol diacrylate, 1,4-butanediol diacrylate, dicyclopentanyl diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tri Acrylate, tetrabromobisphenol A diacrylate, triglycerol diacrylate, trimethylolpropane triacrylate, tris (acryloxyethyl) isocyania Rate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4 -Butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (methacryloxy) phenyl] propane, 2 , 2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxyethoxydie) Toxi) phenyl] propane, 2,2-bis [4- (methacryloxyethoxypolyethoxy) phenyl] propane, tetrabromobisphenol A dimethacrylate, dicyclopentanyl dimethacrylate, dipentaerythritol hexamethacrylate, glycerol dimethacrylate, hydroxy Neopentyl glycol dimethacrylate, dipentaerythritol monohydroxypentamethacrylate, ditrimethylolpropane tetramethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, triglycerol dimethacrylate, trimethylolpropane trimethacrylate, tris (methacryloxyethyl) ) Isocyanurate, allyl methacrylate, divinylben Emissions, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, and diethylene glycol bis allyl carbonate.

  What is necessary is just to adjust suitably the quantity of the "repeating structural unit induced | guided | derived from the crosslinkable monomer" in the polymer which comprises the wall material which concerns on this invention according to the use etc. of an encapsulated material.

[Compound represented by the general formula (1)]
The polymer constituting the wall material according to the present invention may contain “a repeating structural unit derived from the compound represented by the general formula (1)”. That is, a compound represented by the following general formula (1) can be used as a monomer as a raw material of the polymer.

［ただし、Ｒ¹は水素原子又はメチル基を表す。Ｒ²はｔ−ブチル基、脂環式炭化水素基、芳香族炭化水素基、又はヘテロ環基を表す。ｍは０〜３、ｎは０又は１の整数を表す。］

[However, R ¹ represents a hydrogen atom or a methyl group. R ² represents a t-butyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group. m represents an integer of 0 to 3, and n represents an integer of 0 or 1. ]

In the general formula (1), examples of the alicyclic hydrocarbon group represented by R ² include a cycloalkyl group, a cycloalkenyl group, an isobornyl group, a dicyclopentanyl group, a dicyclopentenyl group, and an adamantane group. Examples of the heterocyclic group include a tetrahydrofuran group.

  Specific examples of the compound (monomer) represented by the general formula (1) include the following.

By introducing the R ² group, which is a “bulky” group derived from the compound represented by the general formula (1), into the polymer constituting the wall material of the encapsulated product of the present invention, the polymer molecule can be easily bent. Therefore, the mechanical strength and heat resistance of the polymer are improved. For this reason, the ink composition containing the encapsulated product of this embodiment having the wall material containing the polymer as a main component can provide a printed image (printed product) excellent in abrasion resistance and durability. In addition, by allowing the R ² group, which is a “bulky” group, to exist in the polymer constituting the wall material, the penetration of the organic solvent in the ink composition into the interior of the polymer can be suppressed. The solvent property can be improved. Thereby, in the ink composition in which the water-soluble organic solvent coexists, the dispersion stability of the encapsulated product, the storage stability of the ink composition, and the ejection stability of the ink composition from the inkjet nozzle can be further enhanced.

  The amount of the “repeating structural unit derived from the compound represented by the general formula (1)” in the polymer constituting the wall material according to the present invention may be appropriately adjusted according to the use of the encapsulated product. .

By the way, a polymer having the above “repeating structural unit derived from a crosslinkable monomer” and a polymer having “repeating structural unit derived from the compound represented by the above general formula (1)” have a glass transition temperature ( Tg) has a high mechanical strength, heat resistance, and solvent resistance.
However, an encapsulated material having a wall material containing such a polymer is insufficient in plasticity of the polymer, and when used as a component of an ink composition, it tends to be in a state in which it is difficult to adhere to a recording medium. In some cases, the fixability and abrasion resistance of the encapsulated material to the recording medium may be reduced.

  On the other hand, among the hydrophobic monomers described above, a polymer having a repeating structural unit derived from a monomer having a long-chain alkyl group has flexibility. Therefore, from “a repeating structural unit derived from a crosslinkable monomer” and / or “a repeating structural unit derived from a compound represented by the above general formula (1)” and “a hydrophobic monomer having a long-chain alkyl group” By appropriately adjusting the ratio with the “derived repeating structural unit”, a polymer for wall material having excellent mechanical strength and solvent resistance can be obtained without impairing plasticity preferable as a wall material. An ink composition containing an encapsulated material having a wall material containing such a polymer is excellent in dispersion stability and long-term storage stability even when the ink composition contains a water-soluble organic solvent. Excellent discharge stability. In addition, the ink composition containing the encapsulated product of this embodiment has good fixability of the encapsulated product to various substrates such as paper and plastic, and has a printed portion (ink ink) excellent in abrasion resistance, durability, and solvent resistance. Attachment part) can be provided.

[Polymerization initiator]
As described above, the polymer constituting the wall material of the encapsulated product of the present invention includes the ionic polymerizable surfactant A and / or ionic monomer, the ionic polymerizable surfactant B, and, if necessary, hydrophobic. It is obtained by polymerizing at least one selected from the group consisting of a functional monomer, a crosslinkable monomer and the compound represented by the general formula (1). This polymerization reaction is performed using a polymerization initiator. As this polymerization initiator, a known polymerization initiator can be used, and it is particularly preferable to use a radical polymerization initiator. The polymerization initiator may be water-soluble or oil-soluble, but is preferably a water-soluble polymerization initiator such as potassium persulfate, ammonium persulfate, sodium persulfate, 2,2-azobis- ( 2-methylpropionamidine) dihydrochloride, 4,4-azobis- (4-cyanovaleric acid) and the like. In addition, a redox initiator in which potassium persulfate, ammonium persulfate, sodium persulfate, and the like are combined with sodium sulfite, sodium hyposulfite, ferrous sulfate, or the like can also be used.

Hereinafter, the manufacturing method of the encapsulated product of the present invention will be described based on a preferred embodiment thereof.
As described above, the encapsulated product of the present invention is preferably produced by forming an admicelle.

The manufacturing method of the encapsulated material of this embodiment has the following process 1-process 3.
Step 1: The above ionic polymerizable surfactant A and / or ionic monomer is added to and mixed with an aqueous dispersion of a photochromic material (core material) having a charge on the surface, and the ionic property is added to the surface of the photochromic material. A step of adsorbing the polymerizable surfactant A and / or the ionic monomer.
Process 2: The process of adding and mixing the said ionic polymerizable surfactant B to the liquid mixture which passed through the said process 1.
Step 3: A polymerization initiator is added to and mixed with the liquid mixture that has undergone Step 2 above, and the ionic polymerizable surfactant A and / or ionic monomer and the ionic polymerizable surfactant B are polymerized. And a step of forming a polymer constituting the wall material.

  The aqueous dispersion of the core material used in Step 1 is an aqueous liquid using the core material as a dispersoid and an aqueous solvent as a dispersion medium. This aqueous solvent is mainly composed of water such as deionized water, and may contain various auxiliary agents that help disperse the core substance in water, water-soluble organic solvents, and the like, if necessary.

  In step 1, the amount of the ionic polymerizable surfactant A and / or ionic monomer added to the aqueous dispersion is the total number of moles of ionic groups on the surface of the core material (that is, the core of 1 g of the core material used). The amount of ionic groups present on the surface of the substance [mol / g]) is preferably in the range of 0.5 to 2 times mol, and more preferably in the range of 0.8 to 1.2 times mol. preferable. In the range of 0.5 to 2 moles, the ionic group on the surface of the core material and the ionic group of the ionic polymerizable surfactant A and / or ionic monomer having the opposite charge to the ionic group And the core substance becomes hydrophobic when it is suitably covered with the ionic polymerizable surfactant A and / or ionic monomer, and the admicelle in the above step 2 and thereafter becomes hydrophobic. Formation becomes easy. In the range of 0.8 to 1.2 moles in particular, a more suitable state can be obtained, and an encapsulated product can be obtained with a high yield.

In the above step 1, from the viewpoint of promoting uniform adsorption of the ionic polymerizable surfactant A and / or ionic monomer on the surface of the core material, the ionic polymerizable surfactant is added to the aqueous dispersion of the core material. After adding and mixing the agent A and / or the ionic monomer, it is preferable to irradiate the mixture thus obtained with ultrasonic waves. The ultrasonic irradiation conditions at this time consider the type of the core material, the degree of adsorption of the ionic polymerizable surfactant A and / or ionic monomer on the surface of the core material, the degree of aggregation of the core material, and the like. The irradiation frequency and the irradiation time are determined.
In addition, irradiating ultrasonic waves after the above step 1 may destroy the formed admicelle and increase the amount of polymer particles that do not contain the core material, resulting in a decrease in the yield of the encapsulated product. And the particle size distribution of the encapsulated product may be broadened.

  In addition, the polymer constituting the wall material of the encapsulated product may be represented by the above-described “repeating structural unit derived from a hydrophobic monomer”, “repeating structural unit derived from a crosslinkable monomer”, or “the general formula (1)”. In the case where the “repeating structural unit derived from the compound to be prepared” is contained, these monomers (hydrophobic monomer, crosslinkable monomer, general formula (1) above) are included after step 1 and before step 2. It is preferred to add the compound) to the aqueous dispersion.

  That is, in a preferred embodiment of the encapsulated product of the present invention, an aqueous dispersion of a photochromic substance having a charge on the surface is added to the ionic polymerizable surfactant A and / or the ionic monomer, the hydrophobic monomer, After one or more selected from the group consisting of the crosslinkable monomer and the compound represented by the general formula (1) and the ionic polymerizable surfactant B are sequentially added and mixed in this order, It is produced by adding a polymerization initiator and polymerizing them.

  In the step 2, the addition amount of the ionic polymerizable surfactant B is in the range of 1 to 10 times mol with respect to the ionic polymerizable surfactant A and / or ionic monomer. Preferably, it is in the range of 1-fold mole to 5-fold mole. By setting the addition amount to 1 mol or more, it is possible to effectively suppress the aggregation of the encapsulated product and obtain a dispersion of the encapsulated product having excellent dispersion stability. Moreover, generation | occurrence | production of the polymer particle which is a by-product can be effectively suppressed by making the said addition amount 10 times mole or less.

  By passing through the above step 2, the ionic polymerizable surfactant A and / or ionic monomer electrostatically adheres to the surface of the core material (photochromic material), and the attached ionic polymerizable surfactant A And / or the other monomer such as a hydrophobic monomer is localized on the side opposite to the core material side of the ionic monomer, and the ionic polymerizable surfactant B is ionic at a position farthest from the core material. The group is oriented toward the aqueous phase, and the admicelle is formed.

  Step 3 is performed in a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, and a temperature controller. The polymerization initiator may be added to the mixed solution that has undergone the above-mentioned step 2 by adding the polymerization initiator all at once or divided into the mixed solution heated to a temperature at which the polymerization initiator is activated. Or may be added continuously. Further, after adding the polymerization initiator, the mixed solution may be heated to a temperature at which the polymerization initiator is activated. The polymerization initiator includes a water-soluble polymerization initiator that is soluble in water and an oil-soluble polymerization initiator that is insoluble or hardly soluble in water, and any polymerization initiator can be used in the present invention. When a water-soluble polymerization initiator is used, an aqueous solution obtained by dissolving the water-soluble polymerization initiator in ion-exchanged water can be subjected to a polymerization reaction by dropping it into the mixed solution in the reaction vessel at a predetermined dropping rate. it can. When using an oil-soluble polymerization initiator, add it directly to the liquid mixture in the reaction vessel, or add an oil-soluble polymerization initiator dissolved in a hydrophobic monomer to the liquid mixture to cause a polymerization reaction. Can do.

  The addition amount of the polymerizable initiator is based on the total addition weight of the monomers (ionic monomer such as ionic polymerizable surfactant A and / or ionic monomer, ionic polymerizable surfactant B, and hydrophobic monomer). And preferably 1 to 5% by weight, more preferably 1 to 3% by weight. If the amount added is less than 1% by weight, the polymerization reaction may not proceed sufficiently. If the amount added exceeds 5% by weight, gelation or aggregation may occur.

  The activation of the polymerization initiator can be suitably carried out by raising the temperature of the reaction system to a temperature at which the polymerization initiator is cleaved and initiator radicals are generated. The added polymerization initiator is cleaved to generate an initiator radical, and this initiator radical attacks a polymerizable group of the monomer to cause a polymerization reaction. The polymerization temperature and the polymerization reaction time may be appropriately set according to the type of polymerization initiator used and the type of monomer. In general, the polymerization temperature is preferably in the range of 40 ° C to 90 ° C, and the polymerization time is preferably 3 hours to 12 hours.

  In addition, in the polymerization reaction performed at the said process 3, in order to make the emulsified state of a liquid mixture favorable, as needed, the 1 or more types of emulsifier chosen from the group which consists of an anionic, a nonionic, and a cationic emulsifier Can be used. However, it is necessary to use an emulsifier having the same charge as the ionic polymerizable surfactant B or a nonionic one. This is because the use of an emulsifier having a charge different from that of the ionic polymerizable surfactant B may cause problems such as gelation and aggregation.

  After completion of the above step 3 (after completion of the polymerization), the pH of the obtained aqueous dispersion of the encapsulated product is adjusted to a predetermined range. When an anionic polymerizable surfactant is used as the ionic polymerizable surfactant B constituting the outermost shell of the wall material, the pH is preferably adjusted to 7 to 9, and the cationic polymerizable surfactant is used. When used, it is preferably adjusted to pH 4-6. The pH can be adjusted using a known pH adjusting agent.

  In the aqueous dispersion of the encapsulated product thus obtained, in addition to the encapsulated product, unreacted monomers derived from the monomers used for the production of the encapsulated product (by-products such as monomers and polymer particles not used in the reaction) Therefore, it is preferable to purify the aqueous dispersion to reduce the concentration of unreacted monomers. As a result, when an aqueous dispersion is used in the ink composition, the printing density (amount of photochromic substance applied per unit area) is improved, and bleeding of the printed portion (ink composition adhesion portion) is effectively achieved. It is suppressed. As a method for purifying the aqueous dispersion of the encapsulated product, a centrifugal separation method, an ultrafiltration method, or the like can be used.

Next, the ink composition (ink jet recording ink) of the present invention will be described.
The ink composition of the present invention contains the above-described encapsulated product of the present invention, and further contains a main solvent (a solvent occupying 50% by weight or more of the total weight of the ink composition) in which the encapsulated product is dispersed.

  The content of the encapsulated product is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight, based on the total weight of the ink composition. If the content of the encapsulated material is less than 0.5% by weight, there is a possibility that the light resistance and color developability of the printed material produced by applying the ink composition may be insufficient, and the content is 20% by weight. When it exceeds, there exists a possibility that the dispersion stability and discharge stability of an ink composition may fall.

  As the main solvent of the ink composition of the present invention, water or an organic solvent can be used. The water is preferably pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water. As the organic solvent, a water-soluble organic solvent described later can be used.

  When the ink composition of the present invention is used as an ink for inkjet recording, the composition preferably contains at least an encapsulated product, a water-soluble organic solvent, and water. That is, the ink for inkjet recording of the present invention preferably contains an encapsulated product, a water-soluble organic solvent, and water.

  As the water-soluble organic solvent that can be contained in the ink composition of the present invention, those that are usually used in water-based inks for ink jet recording can be used without particular limitation. For example, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol; ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene Polyhydric alcohols such as glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol Monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol monophenyl ether Polyhydric alcohol ethers such as propylene glycol monophenyl ether; ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetra Amines such as tylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine; amides such as formamide, N, N-dimethylformamide, N, N-dimethylacetamide; 2-pyrrolidone, N-methyl-2- Heterocycles such as pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone; sulfoxides such as dimethyl sulfoxide; sulfones such as sulfolane; urea, acetonitrile, acetone, 1,2-alkane Diol etc. are mentioned. The ink composition of the present invention may contain one of these alone or in admixture of two or more.

  In the inkjet recording ink of the present invention containing an encapsulated product, a water-soluble organic solvent, and water, the content of the water-soluble organic solvent is from the viewpoint of improving the ejection stability of the ink and the permeability to the recording medium. Preferably it is 5-30 weight% with respect to the total weight of an ink.

  In the ink composition of the present invention, a surfactant (for example, a nonionic surfactant such as acetylene glycol-based or acetylene alcohol-based surfactant) or a humectant (for example, glucose, sorbit, maltose, etc.) Sugars; ureas such as urea, thiourea, and ethylene urea), pH adjusters, antiseptics, fungicides, antifoaming agents, ultraviolet absorbers, antioxidants, and the like.

  The ink composition of the present invention has a viscosity at a liquid temperature of 20 ° C. in the range of 2 to 6 mPa · s and a surface tension of 20 to 50 mN / m from the viewpoint of stably discharging from the inkjet nozzle. It is preferable to be in the range. Such physical property values can be achieved, for example, by appropriately adjusting the content of the organic solvent or the surfactant.

  The pH of the ink composition of the present invention depends on the type of ionic group located on the outer surface of the wall material of the encapsulated product, that is, the type of ionic polymerizable surfactant B constituting the outermost shell of the wall material. It is preferable to adjust appropriately. When the ionic polymerizable surfactant B has an anionic group as the ionic group (when the ionic polymerizable surfactant B is an anionic polymerizable surfactant), the pH of the ink composition is Preferably it is 7-11, More preferably, it is 8-9. When the ionic polymerizable surfactant B has a cationic group as an ionic group (when the ionic polymerizable surfactant B is a cationic polymerizable surfactant), the pH of the ink composition is Preferably it is 5-7, More preferably, it is 6-7. The pH of the ink composition can be adjusted using a known pH adjusting agent.

There are the following differences between the ink composition of the present invention and conventionally known ink compositions.
That is, among the conventionally known ink compositions, those that are used without encapsulating the photochromic substance are provided with a dispersant such as a surfactant or a polymer dispersant in order to impart dispersion stability to the photochromic substance. When adsorbed on the surface of the photochromic material, for example, when used in an ink jet method, the dispersing agent adsorbed on the surface of the photochromic material due to the strong shearing force applied when ejected through a thin ink jet nozzle. There is a problem that it is easily detached from the surface, resulting in deterioration of dispersibility and instability of ejection. In addition, a conventional ink composition in which a photochromic substance is encapsulated by a conventional encapsulation method has insufficient solvent resistance of a wall material polymer that coats the photochromic substance. Depending on the solvent or the like, the wall material polymer may be detached or swelled over time, which causes a problem in dispersion stability.

In contrast, since the ink composition of the present invention uses an encapsulated photochromic material (encapsulated material of the present invention) coated with a wall material having excellent solvent resistance, the above-mentioned disadvantages are not recognized at all. The encapsulated material can be stably dispersed in the ink composition over a long period of time, and can be stably ejected through the inkjet nozzle for a long period of time.
Further, since the encapsulated product of the present invention has a substantially spherical shape, the fluidity of the ink composition containing the encapsulated product tends to be Newtonian. This is considered because the ionic groups on the surface of the encapsulated material are regularly and densely oriented toward the aqueous solvent side, and it is considered that an effective electrostatic repulsive force is generated between the encapsulated materials. . Such a shape of the encapsulated product also contributes to the excellent ejection stability of the ink composition of the present invention.

In addition, among conventionally known ink compositions that use a photochromic substance without encapsulating it, not all of the added dispersant is adsorbed on the surface of the photochromic substance. The part dissolves in the solvent without being adsorbed by the photochromic substance. For this reason, the conventionally known ink composition tends to increase in viscosity due to the dissolved dispersant, and the dispersant adsorbed on the surface of the photochromic substance tends to be detached over time. There is a tendency for the viscosity of the to rise over time. For this reason, the conventionally known ink composition has a problem that it is difficult to increase the content of the photochromic substance, and the printing density (amount of applied photochromic substance per unit area) is likely to be insufficient.
In contrast, the ink composition of the present invention hardly increases in viscosity of the ink composition over time, can easily be reduced in viscosity, and contains more photochromic material (encapsulated material) than conventionally known ink compositions. It has the advantage that it can be contained, and can provide a sufficiently high printing density.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to such an Example.
The following Examples 1-2 are examples of the encapsulated product of the present invention, and the following Examples 3-4 are examples of the ink composition (ink jet recording ink) of the present invention.

[Example 1]
(Production of encapsulated MC1 of photochromic material having an anionic group on the surface)
20 g of 1,2-Bis (2-methyl-5-phenyl-3-thienyl) perfluorocyclene (manufactured by Yamada Chemical Co., Ltd.), which is a photochromic substance, and anionic polymerizable surfactant AQUALON KH-10 (1st Kogyo Seiyaku Co., Ltd.) (3.5 g) and ion-exchanged water (200 g) were mixed and ultrasonically irradiated.
Next, 15 g of styrene, 5 g of dicyclopentenyl methacrylate, and 5 g of dodecyl methacrylate were added, mixed and stirred, and further dissolved in 50 g of ion-exchanged water, an anionic polymerizable surfactant Aqualon KH-10 (Daiichi Kogyo Seiyaku Co., Ltd.). Co., Ltd.) 3.5 g was added and irradiated with ultrasonic waves for 30 minutes. This was put into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a temperature controller, a nitrogen introduction tube and an ultrasonic generator. After the internal temperature of the reaction vessel was raised to 80 ° C., an aqueous potassium persulfate solution in which 0.6 g of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 20 g of ion-exchanged water. Polymerized for hours. After the polymerization is completed, the capsule is adjusted to pH 8 with a 2 mol / l potassium hydroxide aqueous solution, subjected to ultrafiltration by a cross flow method using an ultrafiltration apparatus, and the photochromic substance is coated with a wall material mainly composed of a polymer. The compound MC1 was obtained.

[Example 2]
(Production of encapsulated MC2 of photochromic material having an anionic group on the surface)
20 g of 1,2-Bis (5-methyl-2-phenylthiazole-4-yl) perfluorocyclene (manufactured by Yamada Chemical Co., Ltd.), which is a photochromic substance, and anionic polymerizable surfactant AQUALON KH-10 (1st 5 g of Kogyo Seiyaku Co., Ltd.) and 200 g of ion-exchanged water were mixed and dispersed in an Eiger Motor Mill M250 type (Eiger Japan Co., Ltd.) for 2 hours under the conditions of a bead filling rate of 70% and a rotational speed of 5000 rpm. .
Next, 1.5 g of dimethylaminoethylmethyl methacrylate methacrylate as a cationic hydrophilic monomer was added to and mixed with the obtained dispersion, and then treated by irradiation with ultrasonic waves for 30 minutes. Next, 17.3 g of benzyl methacrylate, 7.7 g of dodecyl methacrylate, and 0.05 g of diethylene glycol dimethacrylate were mixed and stirred and mixed, and the anionic polymerizable surfactant previously dissolved in 50 g of ion-exchanged water was added. The agent Aqualon KH-10 (Daiichi Kogyo Seiyaku Co., Ltd.) 5.5 g was added, and the mixture was again irradiated with ultrasonic waves for 30 minutes. This was put into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a temperature controller, a nitrogen introduction tube and an ultrasonic generator. After raising the internal temperature of the reaction vessel to 80 ° C., an aqueous potassium persulfate solution in which 0.6 g of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 20 g of ion-exchanged water, and 6 hours at 80 ° C. while introducing nitrogen. Polymerized. After completion of the polymerization, the pH was adjusted to 8 with a 2 mol / l potassium hydroxide aqueous solution, the coarse particles were removed by filtration through a membrane filter having a pore size of 1 μl, and the photochromic substance was coated with a wall material mainly composed of a polymer. An encapsulated product MC2 was obtained.

[Comparative Example 1]
(Production of Photochromic Material Dispersion H1)
20 g of 1,2-Bis (2-methyl-5-phenyl-3-thienyl) perfluorocyclopentene (manufactured by Yamada Chemical Co., Ltd.) is slowly introduced into Solspers 24000 (trade name, manufactured by Avicia Co., Ltd.) with stirring. did. After the dripped solution was continuously stirred for about 5 minutes, a dispersion treatment was performed for 1 hour using an ultrahomogenizer. After the dispersion treatment, the resultant was treated with a centrifuge for 30 minutes to remove coarse particles, thereby obtaining a target dispersion (non-encapsulated photochromic substance) H1.

[Comparative Example 2]
(Production of photochromic substance dispersion H2)
In Comparative Example 1, 1,2-Bis (5-methyl-) instead of 1,2-Bis (2-methyl-5-phenyl-3-thienyl) perfluorocyclene (manufactured by Yamada Chemical Co., Ltd.) was used as the photochromic substance. 2-phenylthiazole-4-yl) perfluorocyclopentene (manufactured by Yamada Chemical Co., Ltd.) was used in the same manner as in Comparative Example 1 to obtain the target dispersion (unencapsulated photochromic substance) H2. .

(Preparation of ink composition; Examples 3 to 4, Comparative Examples 3 to 4)
Based on the compositions shown in Table 1 below, ink compositions (ink jet recording inks) of Examples 3 to 4 and Comparative Examples 3 to 4 were prepared.

(Evaluation)
The ink compositions of Examples 3 to 4 and Comparative Examples 3 to 4 were evaluated for color developability, light resistance, storage stability, and clogging recovery properties by the following methods. These results are shown in Table 2 below.

<Evaluation of color development>
Using the ink composition, printing was performed on printing paper (Xerox 4200, manufactured by Xerox Co., Ltd.) using an inkjet printer PX-V630 (manufactured by Seiko Epson Co., Ltd.) to obtain a printed matter.
Then, the color density of the printed material produced using the ink composition of Example 3 is visually compared with the color density of the printed material produced using the ink composition of Comparative Example 3, and the same color as that of Comparative Example 3 is obtained. A and B having a lighter color density than Comparative Example 3 were designated as B.
Further, the color density of the printed material produced using the ink composition of Example 4 was visually compared with the color density of the printed material produced using the ink composition of Comparative Example 4, and the same color as that of Comparative Example 4 was obtained. A and B having a lighter color density than Comparative Example 4 were designated as B.

<Evaluation of light resistance>
Using the ink composition, printing was performed on printing paper (Xerox 4200, manufactured by Xerox Co., Ltd.) using an inkjet printer PX-V630 (manufactured by Seiko Epson Co., Ltd.) to obtain a printed matter. After leaving this printed matter for 5 hours, the printed matter was irradiated with light at an illuminance of 14,000 lux for 3 hours using a desktop light resistance tester SUNTEST CPS (manufactured by Heraeus Co., Ltd.). Thereafter, the brightness value is measured with a Gretag densitometer (manufactured by Gretag Co., Ltd.), and the one holding a color density of 100% or less and 80% or more as compared with immediately before light irradiation is A, less than 80% 60 A sample having a color density of at least% was designated as B.

<Evaluation of storage stability>
The ink composition was put in a glass bottle, sealed, and left at 60 ° C. for 2 weeks. The degree of change in the physical property values (viscosity and surface tension) of the ink composition before and after being left is evaluated, and the property value before and after being left is indicated as A (good storage stability), and the physical property value before and after being left as it is. A change was observed as B.

<Evaluation of clogging recovery>
The ink composition is filled in an ink cartridge of an inkjet printer PX-V630 (Seiko Epson Corporation), and further, the recording head of the printer is filled by repeating the cleaning operation, and the ink composition is discharged from the nozzle of the recording head. After confirming the discharge by printing, the printer was left in an environment of 40 ° C. for one month with the nozzles not capped. After leaving, the printer is turned on, and the number of cleaning operations required until all nozzles can be ejected (recovered) is counted. If the number is less than 6, A (good clogging prevention) The number of times exceeding 6 was designated as B.

  As shown in Table 2, the ink composition (ink jet recording ink) of the example prepared using the encapsulated photochromic material is the ink of the comparative example manufactured using the non-encapsulated photochromic material. It exhibits color developability and light resistance equivalent to those of the composition, and is excellent in storage stability and clogging recovery property as compared with the ink composition of the comparative example.

It is a schematic diagram which shows an example of the admicelle produced | generated in the manufacture process of the encapsulated material of this invention. It is a schematic diagram which shows the state which the monomer superposed | polymerized from the state shown in FIG.

Explanation of symbols

1 Photochromic substance (core substance), 2 ionic polymerizable surfactant A, 3 ionic polymerizable surfactant B, 11 cationic group, 12, 12 ′ hydrophobic group, 13, 13 ′ polymerizable group, 14 , 14 'anionic group, 60 wall material (polymer), 100 encapsulated product

Claims (5)

An encapsulated material in which a photochromic substance having a charge on the surface is coated with a wall material mainly composed of a polymer, wherein the polymer has at least a repeating structural unit of the following (A) and a repeating structural unit of the following (B): Encapsulated material.
(A) derived from “an ionic polymerizable surfactant A having a charge opposite to the charge on the surface of the photochromic substance” and / or “an ionic monomer having a charge opposite to the charge on the surface of the photochromic substance”. Repeated structural units.
(B) A repeating structural unit derived from “ionic polymerizable surfactant B having the same or opposite charge as the surface charge of the photochromic substance”.   To the aqueous dispersion of the photochromic substance, the ionic polymerizable surfactant A and / or the ionic monomer and the ionic polymerizable surfactant B are sequentially added and mixed in this order, and then polymerized. The encapsulated product according to claim 1, which is produced by adding an initiator and polymerizing them. The polymer is selected from the group consisting of a repeating structural unit derived from a hydrophobic monomer, a repeating structural unit derived from a crosslinkable monomer, and a repeating structural unit derived from a compound represented by the following general formula (1) The encapsulated product according to claim 1 or 2, further comprising one or more of the above.

[However, R ¹ represents a hydrogen atom or a methyl group. R ² represents a t-butyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group. m represents an integer of 0 to 3, and n represents an integer of 0 or 1. ]   An ink composition containing the encapsulated product according to claim 1.   An ink for inkjet recording comprising the encapsulated product according to any one of claims 1 to 3, a water-soluble organic solvent, and water.

Images