JP2007231214A - Encapsulated resin particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide encapsulated resin particles bringing objects to be highly functional and able to enhance required characteristics such as fixation of colorants, scratch resistance of recorded images, glossiness and the like without spoiling dispersion stability of ink, especially when the ink is used as one component of pigment ink for inkjet recording, and provide a water-based resin emulsion and the pigment ink for inkjet recording. <P>SOLUTION: In the encapsulated resin, resin particles having anionic groups on the surfaces are coated with a wall material comprising a polymer as a main component. The polymer comprises a repeating structural unit derived from at least "a cationically polymerizable surfactant having a cationic group, a hydrophobic group and a polymerizable group" and/or "a hydrophilic monomer having a cationic group" and a repeating unit derived from "an ionically polymerizable surfactant having an ionic group, a hydrophobic group and a polymerizable group". <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to encapsulated resin particles useful as additives such as inks and paints.

  In an ink jet recording method in which ink droplets are ejected from a fine nozzle head and characters and figures are recorded on the surface of a recording medium such as paper, a pigment is recently dispersed in water because of its excellent water resistance and light resistance. Water-based pigment inks that have been used have been used. Such a pigment ink using a pigment as a color material has a characteristic that the pigment stays on the surface layer of the recording medium. Therefore, compared with a dye ink in which the color material dye penetrates into the recording medium, There is a problem that the fixing property to the recording medium is low. For this reason, the recorded image produced using the pigment ink has a drawback that the pigment is liable to fall off by rubbing and the image quality of the recorded image deteriorates with time.

  Therefore, conventionally, in order to improve the fixability of the color material to the recording medium, a method of incorporating various water-soluble resins and resin emulsions in the water-based pigment ink has been employed (for example, see Patent Documents 1 to 3). ).

  However, when these are added to the ink, the stable structure of the pigment dispersion in the ink is broken, and aggregation is likely to occur, which may deteriorate storage stability and ejection stability. In particular, for full-color applications such as photographs and high-definition illustrations that require high-definition printing, output of recorded images with high gloss and high glossiness in addition to less deterioration of image quality over time. However, with the water-based pigment inks described in Patent Documents 1 to 3, such high image quality cannot be obtained.

In addition, the use of inkjet recording technology has been increasing in recent years, and further expansion is expected in the future. Ink jet recording ink has various functions suitable for its use in various industrial and technical fields. There is a demand for highly functional products having There has not yet been provided a technology that completely satisfies the need for higher functionality of ink jet recording ink.
JP 2000-351931 A JP 2003-20421 A JP 2004-143272 A

  Therefore, the object of the present invention can be used in various industries and technical fields, and realizes high performance of objects (things to which the present invention is applied), and particularly as a component of pigment ink for inkjet recording. When used, encapsulated resin particles capable of improving desired properties such as fixing property of a color material, abrasion resistance of a recorded image, and gloss without impairing the dispersion stability of the ink, and the capsule It is an object to provide a water-based resin emulsion using activated resin particles and a pigment ink for inkjet recording.

As a result of intensive studies, the present inventors have found that encapsulated resin particles obtained by coating resin particles having an anionic group on the surface with a wall material mainly composed of a polymer having a specific composition can achieve the above object. did. This invention is made | formed based on this knowledge, The technical structure is as follows.
1) Encapsulated resin particles in which resin particles having an anionic group on the surface are coated with a wall material mainly composed of a polymer, wherein the polymer has “a cationic group, a hydrophobic group, and a polymerizable group; Anionic polymerization having a repeating structural unit derived from a “cationic polymerizable surfactant having a cation” and / or a “hydrophilic monomer having a cationic group”, and an “ionic group, a hydrophobic group and a polymerizable group” Encapsulated resin particles containing at least a repeating structural unit derived from an “active surfactant”.
2) The cationic polymerizable surfactant and / or the hydrophilic monomer and the ionic polymerizable surfactant are sequentially added and mixed in this order to the aqueous dispersion of the resin particles, followed by polymerization. The encapsulated resin particles according to 1), which are produced by adding an initiator and polymerizing them.
3) The encapsulated resin particle according to 1) or 2) above, wherein the polymer further contains a repeating structural unit derived from a hydrophobic monomer.
4) The above polymer further comprising one or more selected from the group consisting of 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 resin particles according to any one of 1) to 3) above.

［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。］
５） 上記１）〜上記４）の何れかに記載のカプセル化樹脂粒子を分散質の全部又は一部とする水性樹脂エマルション。
６） 上記５）記載の水性樹脂エマルションを含有するインクジェット記録用顔料インク。

[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. ]
5) An aqueous resin emulsion in which the encapsulated resin particles according to any one of 1) to 4) above are part or all of the dispersoid.
6) A pigment ink for inkjet recording containing the aqueous resin emulsion described in 5) above.

The encapsulated resin particles and the aqueous resin emulsion of the present invention can be used in various industrial and technical fields using this kind of resin particles, including the field of ink jet recording, and as raw materials for various compositions such as ink compositions. By using it, it is possible to achieve high functionality of the composition. For example, when these are used as a component of a pigment ink for inkjet recording, desired properties such as colorant fixing properties, recorded image abrasion resistance, and glossiness can be obtained without impairing the dispersion stability of the ink. Can be improved. That is, it is possible to obtain an ink jet recording pigment ink that not only satisfies all of the following (a) to (f) but also can exhibit various other functions.
(A) Excellent dispersion stability.
(B) Excellent discharge stability from the recording head.
(C) A recorded matter having excellent image fastness can be obtained.
(D) A recorded matter having a high image printing density can be obtained.
(E) A recorded matter having excellent image abrasion resistance can be obtained.
(F) Even when plain paper is used as the recording medium, it is possible to obtain a recorded matter in which the image is less likely to bleed and the color development of the image is high.

  Moreover, according to the pigment ink for inkjet recording of the present invention, not only all of the above (a) to (f) are satisfied, but also various other functions can be exhibited highly.

  Hereinafter, first, the encapsulated resin particles of the present invention will be described in detail.

  The encapsulated resin particles of the present invention are encapsulated resin particles in which “resin particles having an anionic group on the surface” are coated with a wall material mainly composed of a polymer, and the polymer has at least the following repeating structure: Contains units A and B.

  Repeating structural unit A: A repeating structural unit derived from “a cationic polymerizable surfactant having a cationic group, a hydrophobic group and a polymerizable group” and / or “a hydrophilic monomer having a cationic group”.

  Repeating structural unit B: A repeating structural unit derived from “an ionic polymerizable surfactant having an ionic group, a hydrophobic group and a polymerizable group”.

  The polymer is a main component of the wall material (shell) that covers the “resin particles having an anionic group on the surface” which is a core material, and the content of the polymer in the wall material is: Preferably it is 5 to 50 weight%, More preferably, it is 10 to 40 weight%.

  Such an encapsulated resin particle is obtained by adding the cationic polymerizable surfactant having the charge opposite to the surface charge of the resin particle and / or the hydrophilic property to the aqueous dispersion of the resin particle having an anionic group on the surface. A monomer and the ionic polymerizable surfactant having the same or opposite charge as the surface charge of the resin particles are sequentially added and mixed in this order, and then a polymerization initiator is added to add these (the cationic property). It can be suitably produced by polymerizing (emulsion polymerization) a polymerizable surfactant and / or the hydrophilic monomer and the ionic polymerizable surfactant).

  According to such a method for producing encapsulated resin particles, first, the anionic group of the resin particle and the cationic group of the cationic polymerizable surfactant and / or the cationic group of the hydrophilic monomer are included. Ionically bonded, the hydrophobic group of the cationic polymerizable surfactant and / or the hydrophobic group of the hydrophilic monomer and the hydrophobic group of the ionic polymerizable surfactant face each other, and the ionic property A state is formed in which the ionic groups of the polymerizable surfactant are oriented toward the aqueous phase. That is, before the polymerization initiator is added and polymerized, the arrangement of the various monomers present around the resin particles is extremely highly controlled, and the ionic groups are oriented toward the aqueous phase in the outermost shell. A micelle is formed. Then, the cationic polymerizable surfactant and / or the hydrophilic monomer and the ionic polymerizable surfactant are converted into a polymer in the highly controlled state by the emulsion polymerization reaction. Therefore, the structure of the encapsulated resin particles of the present invention produced by such an emulsion polymerization method is controlled with extremely high accuracy.

  FIG. 1 is a schematic view showing an example of the micelle formed in the process of producing encapsulated resin particles of the present invention. As shown in FIG. 1, resin particles 1 having an anionic group 14 such as a hydrophilic group on the surface thereof are dispersed in a solvent mainly composed of water (aqueous solvent), and a cationic group 11 and a hydrophobic group. Anionic polymerizable surfactant 2 having a cationic polymerizable surfactant 2 having 12 and a polymerizable group 13, an anionic group 14 '(the above ionic group), a hydrophobic group 12' and a polymerizable group 13 ' Coexists with Activator 3 (the ionic polymerizable surfactant) to form micelles. The cationic polymerizable surfactant 2 is disposed so that the cationic group 11 faces the anionic group 14 of the resin particle 1 and adsorbs with a strong ionic bond. Then, the hydrophobic group 12 and the polymerizable group 13 of the cationic polymerizable surfactant 2 are bonded to the hydrophobic group 12 ′ and the polymerizable group of the anionic polymerizable surfactant 3 by hydrophobic interaction. 13 ′ is oriented, and the anionic group 14 ′ of the anionic polymerizable surfactant 3 is oriented in the direction in which the aqueous solvent exists, that is, in the direction away from the resin particles 1.

  Then, the polymerizable group 13 of the cationic polymerizable surfactant 2 and the polymerizable group 13 of the anionic polymerizable surfactant 3 are added to the aqueous dispersion in the state shown in FIG. By polymerizing ', the encapsulated resin particle 100' of the present invention in which the resin particle 1 is coated with a wall material 60 'containing the polymer as a main component as shown in FIG. 2 is produced. Here, since the surface of the wall material 60 ′ has the anionic group 14 ′, the encapsulated resin particle 100 ′ can be dispersed in an aqueous solvent. Even when a hydrophilic monomer having a cationic group is used instead of the cationic polymerizable surfactant 2 or together with the cationic polymerizable surfactant 2, an encapsulated resin particle is prepared in the same manner as described above. can do. During the polymerization, a comonomer that can be copolymerized with the cationic polymerizable surfactant and / or the hydrophilic monomer and the ionic polymerizable surfactant in the aqueous dispersion as necessary. In this case, the wall material is copolymerized from the cationic polymerizable surfactant and / or the hydrophilic monomer, the ionic polymerizable surfactant, and the comonomer. The main component is a copolymer.

  The encapsulated resin particles of the present invention produced through the process of forming micelles as described above have an interface between the core part (resin particles) and the shell part (wall material) as shown in FIG. It consists of a negative charge on the surface of the part and a positive charge on the opposite side of the core part of the shell part that has the opposite charge. The core part and the shell part are clearly (ionically) separated and independent. It has a configuration. Since the encapsulated resin particle of the present invention has such a configuration, for example, the function and characteristics are separated between the core portion and the shell portion by, for example, changing the forming material between the core portion and the shell portion. As a result, various functions can be imparted to the entire encapsulated resin particles, and the functions of the object can be enhanced in various applications. Examples of the functional separation between the core part and the shell part include, for example, a resin (polymer) that forms the core part and the shell part designed with a core part / shell part = high Tg / low Tg, or this The reverse is mentioned.

  In general, there is a seed emulsion polymerization method (seed polymerization method) as a method in which resin particles are used as seeds and a monomer is newly added to repeat polymerization. If this method is used, the particle size distribution can be made uniform at the same time as the particle size is increased. Moreover, it is possible to form what is called a core-shell structure by using the resin particle used as a seed as a core part, and using different resin for a shell part. However, resin particles produced by seed polymerization are generally unclear at the boundary between the core and shell, making it difficult to separate the functions and properties between the core and shell. The degree of freedom is low, and the effect (enhancement of the object) of the encapsulated resin particles of the present invention described above cannot be obtained.

  That is, the seed polymerization method and the emulsion polymerization method (hereinafter, also referred to as the emulsion polymerization method according to the present invention) through the above-described micelle formation process according to the present invention use seed particles produced by various polymerization methods, The seed polymerization method is common in that various seed monomers are polymerized on the seed particles to enlarge the seed particles. In the seed polymerization method, the seed particles and the monomer (polymer) are simply adsorbed on the seed particles by the monomer added in the polymerization system. In the emulsion polymerization method according to the present invention, as described above, the ionic interaction between the monomer and the repeating structural unit constituting the ionic compound is not particularly utilized. The difference is that seed particles are enlarged by using the basic interaction. Due to the difference between the two, in the seed polymerization method, the arrangement form of the monomer tends to be random, and a core-shell structure in which the boundary between the core part and the shell part is unclear is obtained. In the above emulsion polymerization method, a core-shell structure in which the core part and the shell part are clearly separated and independent is obtained through a micelle formation process in which the arrangement form of the monomers is extremely highly controlled.

Thus, the encapsulated resin particles of the present invention are
(A) Excellent dispersion stability
(B) Excellent discharge stability from the recording head.
(C) It is possible to obtain a recorded matter having excellent image fastness.
(D) A recorded matter having a high image printing density can be obtained.
(E) It is possible to obtain a recorded material having excellent image abrasion resistance.
(F) An ink jet satisfying all of the above (a) to (f), in which even when plain paper is used as the recording medium, it is possible to obtain a recorded matter in which an image is less likely to bleed and an image is highly colored. A pigment ink for recording can be produced.

  The encapsulated resin particles coated with a polymer prepared in advance on the resin particles by using a method other than the above-described emulsion polymerization method according to the present invention, such as a phase inversion emulsification method and an acid precipitation method. Then, because the coating state on the resin particles is limited because the polymer is prepared in advance, the coating state on the polymer resin particles satisfying all of the above (a) to (f) is not achieved. It is considered a thing.

  In addition, in the encapsulated resin particle of the present invention, the wall material can be multi-layered. When the wall material is multilayered, taking encapsulated resin particles having a wall material with a two-layer structure as an example, first, the resin particles are added to the aqueous dispersion of the resin particles having an anionic group on the surface. The ionic polymerizable surfactant having the same or opposite charge as the surface charge of the resin particles after adding and mixing the cationic polymerizable surfactant and / or the hydrophilic monomer having a charge opposite to the surface charge of After mixing and emulsifying the agent, a polymerization initiator is added and polymerized in water to form a first wall material. The steps so far are the same as the above-described method for producing the encapsulated resin particles having the single-layer wall material. Next, an ionic polymerizable surfactant having a charge opposite to the charge on the surface of the first wall material (surface on the outermost shell side) is added to the aqueous dispersion of encapsulated resin particles having the first wall material. And / or “hydrophilic monomer having a charge opposite to the charge on the surface of the first wall material”, and after mixing, “ionicity having the same or opposite charge as the charge on the surface of the first wall material” After adding, mixing and emulsifying the “polymerizable surfactant”, a polymerization initiator is added and polymerized in water to form a second wall material. Encapsulated resin particles having a wall material having a multilayer structure of three or more layers can be preferably produced by sequentially forming the wall material toward the outside of the resin particles according to the above method.

  Here, the aspect ratio (long and short) of the encapsulated resin particles of the present invention is 1.0 to 1.3, and the Zingg index is 1.0 to 1.3 (more preferably 1.0 to 1). .2) is preferred.

When the short diameter of a particle is b, the long diameter is l, and the thickness is t (l ≧ b ≧ t> 0), the aspect ratio (long / shortness) is 1 / b (≧ 1), and the flatness is b / t ( ≧ 1) and Zingg index = long / short / flatness = (l · t) / b ² . That is, the true sphere has an aspect ratio of 1 and a Zingg index of 1.

  When the Zingg index is larger than 1.3, the encapsulated resin particles become flatter and the isotropic property is lowered. The method of bringing the aspect ratio and Zingg index within the above range is not particularly limited, but the encapsulated resin particles in which the resin particles having ionic groups on the surface are coated with the polymer by the emulsion polymerization method according to the present invention described above are as follows. This condition can be easily satisfied.

  In addition, in the encapsulated resin particles produced by a method other than the above-described emulsion polymerization method according to the present invention, such as an acid precipitation method or a phase inversion emulsification method, the aspect ratio and the Zingg index are unlikely to fall within the above ranges.

  On the other hand, the encapsulated resin particles of the present invention produced using the emulsion polymerization method according to the present invention described above have the aspect ratio and Zingg index within the above ranges and become spherical, so that the ink flow characteristics are low. It tends to be Newtonian and has excellent ejection stability. Further, since it is spherical, when encapsulated on a recording medium such as paper, the encapsulated resin particles are arranged at a high density on the recording medium, and the printing density and color development can be expressed with high efficiency. Further, since it is spherical, it is excellent in dispersibility and dispersion stability.

Below, the various raw materials etc. which comprise the encapsulated resin particle of this invention are demonstrated.
[Resin particles]
The resin particles that are the core material of the encapsulated resin particles of the present invention are fine particles containing 50% by weight or more, preferably 90% by weight or more of resin, and have an anionic group on the surface of the particles. The anionic group was selected from, for example, a sulfonic acid group, a sulfinic acid group, a carboxyl group, a phosphoric acid group, a sulfonic acid ester group, a sulfinic acid ester group, a phosphoric acid ester group, and a group thereof. A thing can be illustrated suitably. Examples of the salt include Na salt, K salt, Ca salt, and organic amine salt.

  Examples of the resin constituting the resin particles include styrene derivatives such as styrene, methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, dichlorostyrene, t-butylstyrene, bromostyrene, and p-chloromethylstyrene; acrylic acid Methyl, ethyl acrylate, 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 , Phenyl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate Relate, dicyclopentenyloxyethyl acrylate, tetrahydrofurfuryl acrylate, and isobornyl acrylate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxy Monofunctional acrylic acid esters such as polyethylene glycol acrylate, nonylphenol EO adduct acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl diglycol acrylate, octoxy polyethylene glycol polypropylene glycol monoacrylate, etc. Methyl methacrylate, ethyl methacrylate, 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, benzyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, cyclohexyl methacrylate, Tetrahydrofurfuryl methacrylate, t- Monofunctional methacrylic acid such as butylcyclohexyl methacrylate, behenyl methacrylate, dicyclopentanyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, butoxymethyl methacrylate, isobornyl methacrylate, octoxy polyethylene glycol polypropylene glycol monomethacrylate, etc. Esters; allyl compounds such as allylbenzene, allyl-3-cyclohexanepropionate, 1-allyl-3,4-dimethoxybenzene, allylphenoxyacetate, allylphenylacetate, allylcyclohexane, and allyl carboxylate; fumaric acid , Maleic acid, itaconic acid and other unsaturated esters; N-substituted maleimides, cyclic olefins, etc. Such a monomer having a polymerizable group.

  As the resin used as the material for forming the resin particles, one or more of them may be appropriately selected according to the use of the encapsulated resin particles.

  The resin particles can be produced by a known emulsion polymerization method (for example, a method for producing a synthetic resin emulsion described in JP 2000-72803 A). For example, the resin particles can be produced by emulsion polymerization of the forming material (monomer) in water containing a polymerization initiator and an emulsifier. Usually, the resin particles are obtained in the form of an aqueous resin emulsion in which the resin particles are a dispersoid and a solvent mainly composed of water (aqueous solvent) is used as a dispersion medium.

The average particle diameter of the resin particles may be appropriately selected according to the use of the encapsulated resin particles, etc. In particular, when the average particle diameter is in the range of 20 to 300 nm, the dispersion stability and ejection stability are improved. It is possible to obtain encapsulated resin particles that are excellent and that can more reliably produce an inkjet recording ink that can increase the printing density of an image. In addition, the average particle diameter here means the measured value of the laser light scattering method.
[Cationically polymerizable surfactant]
The cationic polymerizable surfactant is a polymerization component of the repeating structural unit A contained in the polymer which is the main component of the wall material of the encapsulated resin particle of the present invention, and includes a cationic group, a hydrophobic group, and a polymerizable group. And have.

The cationic 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.

  The hydrophobic group is preferably one or two or more selected from the group consisting of an alkyl group having 8 to 16 carbon atoms and an aryl group such as a phenyl group and a phenylene group, and an alkyl group and an aryl group in the molecule. It can also have both groups.

  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.

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, examples of the polymerizable group include those described above.

  Specific examples of the cationic polymerizable surfactant include dimethylaminoethyl chloride methacrylate, dimethylaminoethyl octyl chloride methacrylate, dimethylaminoethyl cetyl chloride methacrylate, dimethylaminoethyl decyl chloride methacrylate, and methacrylic acid. Examples thereof include dimethylaminoethyl dodecyl chloride salt, dimethylaminoethyl tetradecyl chloride salt methacrylate, and the like.

The cationic polymerizable surfactants exemplified above can be used in the present invention alone or as a mixture of two or more.
[Hydrophilic monomer]
The hydrophilic monomer is a polymerization component of the above repeating structural unit A contained in the polymer which is the main component of the wall material of the encapsulated resin particle of the present invention, and is water-soluble having at least a polymerizable group in addition to the cationic group. It is a compound of this. Examples of the cationic group and the polymerizable group include those described in the above section [Cationically polymerizable surfactant].

  Preferred specific examples of the hydrophilic monomer include dimethylaminoethyl methyl chloride salt, dimethylaminoethyl benzyl methacrylate salt, methacryloyloxyethyltrimethylammonium chloride salt, diallyldimethylammonium chloride salt, and 2-hydroxy-3- And 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 hydrophilic monomers exemplified above can be used in the present invention alone or as a mixture of two or more.
[Ionic polymerizable surfactant]
The ionic polymerizable surfactant is a polymerization component of the repeating structural unit B contained in the polymer that is the main component of the wall material of the encapsulated resin particle of the present invention, and includes an ionic group, a hydrophobic group, and a polymerizable group. And have. Examples of the hydrophobic group and the polymerizable group include those described in the above section [Cationically polymerizable surfactant].

  Examples of the ionic group include an anionic group and a cationic group. An ionic polymerizable surfactant having an anionic group as the ionic group is referred to as an anionic polymerizable surfactant, and An ionic polymerizable surfactant having a cationic group as a functional group is referred to as a cationic polymerizable surfactant. In the present invention, any of an anionic polymerizable surfactant and a cationic polymerizable surfactant may be used as the ionic polymerizable surfactant, and any one may be appropriately selected according to the use of the encapsulated pigment. It ’s fine.

  Examples of the cationic polymerizable surfactant (the ionic polymerizable surfactant having a cationic group as the ionic group) include those described in the above section [Cationic polymerizable surfactant]. .

The anionic polymerizable surfactant (the ionic polymerizable surfactant having an anionic group as the ionic group) will be described below.
[Anionic polymerizable surfactant]
Examples of the anionic group include those selected from the group of sulfonic acid group, sulfinic acid group, carboxyl group, phosphoric acid group, sulfonic acid ester group, sulfinic acid ester group, phosphoric acid ester group, and salts thereof. It can illustrate suitably. Examples of the salt include Na salt, K salt, Ca salt, and organic amine salt.

  Specific examples of the anionic polymerizable surfactant include an anionic allyl derivative as described in JP-B-49-46291, JP-B-1-24142, or JP-A-62-104802. Anionic propenyl derivatives as described in JP-A-62-221431, anionic acrylics as described in JP-A-62-34947 or JP-A-55-11525 Examples thereof include acid derivatives and anionic itaconic acid derivatives described in JP-B-46-34898 or JP-A-51-30284.

  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 resin particles obtained by encapsulating the resin particles 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). ]

上記一般式（３１０）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。例えば、旭電化工業株式会社のアデカリアソープＳＥ−１０Ｎは、上記一般式（３１０）で表される化合物において、Ｍ¹がＮＨ₄、Ｒ³¹がＣ₉Ｈ₁₉、ｍ＝１０とされる化合物である。旭電化工業株式会社のアデカリアソープＳＥ−２０Ｎは、上記一般式（３１０）で表される化合物において、Ｍ¹がＮＨ₄、Ｒ³¹がＣ₉Ｈ₁₉、ｍ＝２０とされる化合物である。

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。］
上記一般式（３３）、上記〔化１０〕に記載の式で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、第一工業製薬株式会社製のアクアロンＫＨシリーズ（アクアロンＫＨ−５、及びアクアロンＫＨ−１０）（以上、商品名）などを挙げることができる。アクアロンＫＨ−５は、上記一般式（３３）で表される化合物において、ｒが９及びｓが５である化合物と、ｒが１１及びｓが５である化合物との混合物である。アクアロンＫＨ−１０は、上記〔化１０〕に記載の式で表される化合物において、ｒが９及びｓが１０である化合物と、ｒが１１及びｓが１０である化合物との混合物である。

[Wherein, r is 9 or 11, and s is 5 or 10. ]
A commercial item can also be used as a compound (anionic polymerizable surfactant) represented by the formula of the above general formula (33) and the above [Chemical Formula 10]. 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 a compound represented by the general formula (33) wherein r is 9 and s is 5, and a compound where r is 11 and s is 5. Aqualon KH-10 is a mixture of a compound represented by the formula described in the above [Chemical Formula 10] wherein r is 9 and s is 10, and a compound where r is 11 and s is 10.

  Moreover, as an 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。]
上記一般式（３４）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、旭電化工業株式会社製のアデカリアソープＳＲシリーズ（アデカリアソープＳＲ−１０、ＳＲ−２０、ＳＲ−１０２５）（以上、商品名）などを挙げることができる。アデカリアソープＳＲシリーズは、上記一般式（３４）において、ＢがＮＨ₄で表される化合物であって、ＳＲ−１０はｎ＝１０、ＳＲ−２０はｎ＝２０である化合物である。

[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.

  In addition, as the anionic polymerizable surfactant used in the present invention, a 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。］
上記一般式（Ａ）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、第一工業製薬株式会社製のアクアロンＨＳシリーズ（アクアロンＨＳ−１０、ＨＳ−２０、及びＨＳ−１０２５）（以上、商品名）が挙げられる。

[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.

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

上記一般式（３５）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、三洋化成工業株式会社のエレミノール ＪＳ−２を挙げることができ、上記一般式（３５）において、ｍ＝１２で表される化合物である。

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.

上記一般式（３６）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、三洋化成工業株式会社のエレミノール ＲＳ−３０を挙げることができ、上記一般式（３６）において、ｎ＝９で表される化合物である。

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.

  In addition, as the anionic polymerizable surfactant used in the present invention, for example, a compound represented by the following general formula (37) can be used.

[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。]
上記一般式（３７）で表される化合物（アニオン性重合性界面活性剤）としては、市販品を用いることもできる。市販品としては、例えば、日本乳化剤株式会社のＡｎｔｏｘ ＭＳ−６０を挙げることができ、上記一般式（３７）において、Ｒ₁がメチル基、Ｒ₂、Ｒ₃、Ｒ₄、Ｒ₅が水素原子又はアルキル基、ｍ及びｎが正の整数、Ｘがアンモニウムで表される化合物がこれに当たる。

[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 (the ionic polymerizable surfactant having an anionic group as the ionic group) can be used alone or as a mixture of two or more in the present invention. .
[Other polymerization components]
In the polymer which is the main component of the wall material of the encapsulated resin particle of the present invention, in order to further enhance the functionality of the encapsulated resin particle, the above-described polymerization component (cationic polymerizable surfactant and / or hydrophilic) is used. In addition to the above-mentioned repeating structural units A and B derived from a functional monomer and an ionic polymerizable surfactant, other repeating structural units can be contained as required. Examples of the other repeating structural unit include “a repeating structural unit derived from a hydrophobic monomer” and “a repeating structural unit derived from a crosslinkable monomer”.

Below, the polymerization component (polymerizable monomer) which comprises the other repeating structural unit which can be contained in the said polymer is demonstrated.
[Hydrophobic monomer]
The repeating structural unit derived from the hydrophobic monomer has the film-forming properties of the encapsulated resin particles, the strength of the wall material, chemical resistance, water resistance, light resistance, weather resistance, optical properties, other physical properties and chemical properties. Effective for control, especially when encapsulated resin particles are used in pigment inks for ink jet recording, the required properties such as pigment (coloring material) fixability, printed portion rubbing resistance, water resistance and solvent resistance. It is effective in satisfying.

  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. Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, and a propyl group, and examples of the alicyclic hydrocarbon group include a cyclohexyl group, a dicyclopentenyl group, a dicyclopentanyl group, and an isobornyl group. Examples of the aromatic hydrocarbon group include a benzyl group, a phenyl group, and a naphthyl group.

  As the polymerizable group of the hydrophobic monomer, the same group as described in the above section [Cationically polymerizable surfactant] can be used.

  Specific examples of the hydrophobic monomer include those listed as resins constituting the resin particles in the section [Resin Particles].

The proportion of the hydrophobic monomer in the polymer (the main component of the wall material) according to the present invention is preferably 50 to 95% by weight, and preferably 60 to 90% by weight based on the total monomers contained in the polymer as constituent units. % Is more preferable.
[Crosslinking monomer]
By incorporating a repeating structural unit derived from a crosslinkable monomer into the polymer which is the main component of the wall material, a crosslinked structure is formed in the polymer, and the solvent resistance (the solvent contained in the ink for ink jet recording is reduced). It is possible to improve the property of not easily entering the polymer coating the resin particles. When the solvent penetrates into the interior of the polymer that coats the resin particles, the polymer swells or deforms, and the orientation state of the anionic group of the encapsulated resin particles facing the aqueous medium is disturbed. The dispersion stability and the like may be reduced. In such a case, by forming a crosslinked structure in the polymer that coats the resin particles, the solvent resistance of the encapsulated resin particles is improved, and in the ink composition in which the water-soluble organic solvent coexists, the encapsulated resin particles Dispersion stability, storage stability of the ink composition, and ejection stability of the ink composition from the inkjet head 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 tris 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.

  The proportion of the crosslinkable monomer in the polymer (main component of the wall material) according to the present invention is preferably 0 to 50% by weight, and 0 to 10% by weight with respect to the total monomers contained as structural units in the polymer. % Is more preferable.

  The polymer which is the main component of the wall material according to the present invention may further contain “a repeating structural unit derived from a compound represented by the following general formula (1)”. That is, as the polymerizable monomer used for synthesizing the polymer, a compound represented by the following general formula (1) can be used.

［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。］
上記一般式（１）において、Ｒ²が示す脂環式炭化水素基としては、シクロアルキル基、シクロアルケニル基、イソボルニル基、ジシクロペンタニル基、ジシクロペンテニル基、及びアダマンタン基等が挙げられ、ヘテロ環基としてはテトラヒドロフラン基等が挙げられる。

[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.

本発明のカプセル化樹脂粒子に係る壁材の主成分であるポリマー中に、上記一般式（１）で表される化合物由来の「嵩高い」基である上記Ｒ²基を入れることによって、ポリマーの分子のたわみやすさが低下する、即ち、分子の運動性が低下するため、ポリマーの機械的強度や耐熱性が向上する。このため、該ポリマーを主成分とする壁材を有する本態様のカプセル化樹脂粒子を含むインク組成物は、優れた耐擦性と耐久性を有する印刷物を提供することができる。また、壁材を構成するポリマー中に、"嵩高い"基である上記Ｒ²基を存在させることによって、ポリマー内部へのインク組成物中の有機溶媒の浸透を抑制できることから、カプセル化樹脂粒子の耐溶剤性を優れたものにすることができる。これによって、水溶性有機溶媒が共存するインクジェット記録用インク組成物において、色材粒子の分散性や、インク組成物の保存安定性、さらにインクジェットヘッドからのインク組成物の吐出性をも高めることができる。

By introducing the R ² group, which is a “bulky” group derived from the compound represented by the general formula (1), into the polymer that is the main component of the wall material according to the encapsulated resin particle of the present invention, the polymer Since the flexibility of the molecule is reduced, that is, the mobility of the molecule is reduced, the mechanical strength and heat resistance of the polymer are improved. For this reason, the ink composition containing the encapsulated resin particles of this embodiment having the wall material mainly composed of the polymer can provide a printed matter having excellent abrasion resistance and durability. Moreover, since the penetration of the organic solvent in the ink composition into the polymer can be suppressed by making the R ² group which is a “bulky” group present in the polymer constituting the wall material, the encapsulated resin particles The solvent resistance can be made excellent. As a result, in the ink composition for ink jet recording in which a water-soluble organic solvent coexists, the dispersibility of the colorant particles, the storage stability of the ink composition, and the discharge property of the ink composition from the ink jet head can be improved. it can.

  The polymer having the above “repeating structural unit derived from a crosslinkable monomer” and the polymer having “repeating structural unit derived from the compound represented by the general formula (1)” have high Tg, It has the advantage of excellent strength, heat resistance and solvent resistance.

  However, the encapsulated resin particles having such a wall material containing a polymer are insufficient in plasticity of the polymer, and when used as a component of an ink composition, are likely to be in a state in which they are difficult to adhere to a recording medium, As a result, the fixability and abrasion resistance of the encapsulated resin particles to the recording medium may be lowered.

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, “a repeating structural unit derived from a crosslinkable monomer” and / or “a repeating structural unit derived from a compound (monomer) represented by the above general formula (1)” and “a monomer having a long-chain alkyl group” By appropriately adjusting the ratio with the “repeating structural unit derived from”, 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 encapsulated resin particles having a wall material containing such a polymer is excellent in dispersion stability and long-term storage stability even if the ink composition contains a water-soluble organic solvent. Excellent discharge stability from the head. In addition, the ink composition containing the encapsulated resin particles of this embodiment has good fixability of the encapsulated resin particles to a recording medium such as paper or exclusive paper for inkjet recording, and has excellent abrasion resistance, durability, and resistance. A printed image having excellent solvent properties can be provided.
[Polymerization initiator]
As described above, the polymer constituting the wall material of the encapsulated resin particle of the present invention includes a cationic polymerizable surfactant and / or a hydrophilic monomer, an ionic polymerizable surfactant, and optionally hydrophobic. It is obtained by polymerizing a monomer, a crosslinkable monomer, and other polymerizable monomers such as the compound represented by the general formula (1). This polymerization reaction can be performed using a known polymerization initiator, and it is particularly preferable to use a radical polymerization initiator. As the polymerization initiator, a water-soluble polymerization initiator is preferable, and potassium persulfate, ammonium persulfate, sodium persulfate, 2,2-azobis- (2-methylpropionamidine) dihydrochloride, and 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.
[Other ingredients]
The polymer constituting the wall material of the encapsulated resin particle of the present invention includes, as a component other than the above-described polymerization component (polymerizable monomer), an ultraviolet absorber and a light stabilizer as long as the effects of the present invention are not impaired. , Antioxidants, flame retardants, plasticizers, waxes and the like can be included.
[Method for producing encapsulated resin particles]
Below, the manufacturing method of the encapsulated resin particle of this invention is demonstrated.

  The method for producing encapsulated resin particles of the present invention comprises a step of producing resin particles (resin particles having an anionic group on the surface) serving as a core (resin particle production step), and resin particles obtained in the step, The process is roughly divided into two processes (encapsulation process) for coating with a wall material mainly composed of a polymer.

  The resin particle production process can be performed according to a conventional method by a general known emulsion polymerization method using the above-described raw materials. The target resin particles are usually obtained in the form of an oil-in-water (o / w) emulsion (aqueous dispersion).

  The encapsulation step is a step of forming a wall material that covers the resin particles, and since the polymerization reaction of the various polymerization components (polymerizable monomers) described above is performed, an ultrasonic generator, a stirrer, a reflux condenser, and a dropwise addition It is preferable to use a reaction vessel equipped with a funnel and a temperature controller.

  The encapsulating step will be further described. In this step, first, in the aqueous dispersion of “resin particles having an anionic group on the surface” obtained in the resin particle production step, “cationic group and hydrophobic group and A cationic polymerizable surfactant having a polymerizable group and / or a “hydrophilic monomer having a cationic group” are added and mixed to prepare a mixed solution. Here, in order to make the cationic group of the cationic polymerizable surfactant and / or the hydrophilic monomer easily ionically bond to the anionic group on the surface of the resin particle, Is preferably irradiated.

  The amount of the cationic polymerizable surfactant and / or the hydrophilic monomer added to the aqueous dispersion is the total number of ionic groups on the surface of the resin particles (that is, present on the surface of 1 g of the resin particles used). The amount of anionic group [mol / g] is preferably in the range of 0.5 to 2 times mol, more preferably in the range of 0.8 to 1.2 times mol. By adding 0.5 times mole or more of the cationic polymerizable surfactant and / or the hydrophilic monomer to the total molar amount of anionic groups on the surface of the resin particles, good dispersion can be achieved by the subsequent polymerization reaction. Encapsulated resin particles having properties can be obtained. This is considered to be because the resin particles can be sufficiently covered with the cationic polymerizable surfactant and / or the hydrophilic monomer. On the other hand, the amount of the cationic polymerizable surfactant and / or the hydrophilic monomer added is not more than twice the total molar amount of the anionic groups on the surface of the resin particles, so that no resin particles are present. Generation | occurrence | production of a polymer particle (particle | grains which consist only of a polymer) can be suppressed. This is considered to be because the amount of the cationic polymerizable surfactant and / or the hydrophilic monomer that is not adsorbed by the resin particles can be reduced.

  Next, when using other polymerization components such as the above-mentioned hydrophobic monomer, the mixture is mixed with a hydrophobic monomer, a crosslinkable monomer, the compound represented by the above general formula (1), and other known compounds. One or more other polymerization components selected from the group consisting of polymerizable monomers are added. In addition, also when adding and mixing these other polymerization components, it is preferable to irradiate the mixed solution with ultrasonic waves.

  Next, “an ionic polymerizable surfactant having an ionic group, a hydrophobic group, and a polymerizable group” is added to the mixed solution, and the mixture is preferably mixed while performing ultrasonic irradiation. The addition amount of the ionic polymerizable surfactant is preferably in the range of 1 to 10 times mol with respect to the cationic polymerizable surfactant and / or the hydrophilic monomer, and 1.0 times. More preferably, it is in the range of mol to 5 times mol. By setting the addition amount to 1 mol or more, aggregation of encapsulated resin particles can be suppressed, and an encapsulated resin particle dispersion excellent in dispersion stability can be obtained. Furthermore, the ink composition using the encapsulated resin particle dispersion has excellent ejection stability from the ink jet recording head, improved adsorptivity to paper fibers, and excellent printing density and color development. . Moreover, by making the said addition amount 10 times mole or less, the quantity of the said ionic polymerizable surfactant which does not contribute to the encapsulation reaction of a pigment particle can be reduced, and generation | occurrence | production of the polymer particle which does not have a resin particle can be suppressed.

  Through the above steps, the cationic polymerizable surfactant and / or the hydrophilic monomer having a charge opposite to the anionic group is electrostatically attached to the surface of the resin particle having an anionic group on the surface. In some cases, a polymerizable monomer such as the hydrophobic monomer is localized on the outer side, and the ionic polymerizable group having the same or opposite charge as the anionic group on the surface of the resin particle on the outer side. It is presumed that the surfactant orients its ionic group toward the aqueous phase and micelles are formed.

  In addition, in the case where the formation of micelles is obtained without performing ultrasonic irradiation in the above step, ultrasonic irradiation is not always necessary, but in order to control the particle size of the encapsulated resin particles, It is particularly preferable to irradiate the mixed liquid (aqueous dispersion) to which various components are added with ultrasonic waves.

  Next, a polymerization initiator is added to the mixed solution in which the micelles are formed to perform a polymerization reaction. The polymerization initiator may be added to the liquid mixture heated to a temperature at which the polymerization initiator is activated, or the polymerization initiator may be added at once or dividedly or continuously. Moreover, after adding a polymerization initiator, you may heat the said liquid mixture to the temperature in which a polymerization initiator is activated. In the present invention, a water-soluble polymerization initiator is preferably used as a polymerization initiator, and an aqueous solution obtained by dissolving it in pure water is preferably added dropwise to the aqueous dispersion in the reaction vessel. The added polymerization initiator is cleaved to generate initiator radicals, which attack the polymerizable group of the polymerizable surfactant and the polymerizable group of the polymerizable monomer to cause a polymerization reaction. The polymerization temperature and the polymerization reaction time vary depending on the type of polymerization initiator used and the type of polymerizable monomer, but those skilled in the art can easily set preferable polymerization conditions as appropriate. In general, the polymerization temperature is preferably in the range of 60 ° C to 90 ° C, and the polymerization time is preferably 3 hours to 10 hours.

  In addition, since the said polymerization reaction is performed using ionic polymerizable surfactant, the emulsification state of a liquid mixture is often favorable even if it does not use an emulsifier. Therefore, it is not always necessary to use an emulsifier, but at least one selected from the group consisting of known anionic, nonionic, and cationic emulsifiers may be used as necessary. Further, by adding an antioxidant, a plasticizer, or the like to the mixed solution before polymerization or during the polymerization reaction, these additives can be contained in the polymer.

  After completion of the polymerization reaction, it is preferable to adjust the pH of the obtained aqueous dispersion of encapsulated resin particles of the present invention to a range of 7.0 to 9.0 and further perform filtration. Filtration is preferably ultrafiltration.

  The encapsulated resin particles of the present invention obtained through the above steps have a high dispersion stability with respect to an aqueous solvent, which is completely covered with a wall material mainly composed of a polymer ( It is thought that this is because the hydrophilic groups in the polymer constituting the wall material are regularly oriented toward the aqueous solvent.

  The volume average particle diameter (diameter) of the encapsulated resin particles of the present invention thus obtained is preferably 400 nm or less, more preferably 300 nm or less, and particularly preferably 20 to 200 nm. The volume average particle diameter of the encapsulated resin particles is controlled by irradiating the reaction mixture with ultrasonic waves under a predetermined irradiation condition (mainly the difference in irradiation energy, which can be controlled by frequency and irradiation time, for example) before the polymerization reaction starts. The difference between whether or not to irradiate the reaction mixture with ultrasonic waves during the polymerization reaction, and the control of the irradiation conditions when irradiating the reaction mixture with ultrasonic waves during the polymerization reaction. it can.

  The encapsulating resin particles of the present invention have film-forming properties, wall material strength, chemical resistance, water resistance, light resistance, weather resistance, optical properties, other physical properties and chemical properties as the main components of the wall material. By appropriately controlling the composition, structure, etc. of a certain polymer, it is possible to make it suitable for the application of encapsulated resin particles.

  In particular, when the encapsulated resin particles are used in a pigment ink for inkjet recording, the fixability of the pigment (coloring material), the abrasion resistance and the glossiness of the printed part are polymers (copolymers, The glass transition temperature (Tg) of the copolymer) can be controlled.

  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。）
即ち、本発明のカプセル化樹脂粒子の置かれた温度環境が、該カプセル化樹脂粒子の壁材を構成する共重合体のガラス転移温度よりも高い場合には、この共重合体は小さな力で大きな変形が起こる状態となり、さらに融点に達すると溶融する。このとき、近傍に他のカプセル化樹脂粒子が存在するとカプセル化樹脂粒子同士が融着して成膜する。また、融点まで環境温度が達しない場合であっても、カプセル化樹脂粒子同士が強い力によって接触するような場合は、各カプセル化樹脂粒子を被覆している共重合体分子同士が絡み合うことが可能となるような条件が整えば、カプセル化樹脂粒子を覆う共重合体（コポリマー）同士は融着することもある。

(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 resin particles of the present invention are placed is higher than the glass transition temperature of the copolymer constituting the wall material of the encapsulated resin particles, the copolymer has a small force. Large deformation occurs, and when it reaches the melting point, it melts. At this time, if other encapsulated resin particles are present in the vicinity, the encapsulated resin particles are fused to form a film. Further, even when the environmental temperature does not reach the melting point, when the encapsulated resin particles come into contact with each other with a strong force, the copolymer molecules covering the encapsulated resin particles may be entangled with each other. If conditions that enable it are prepared, the copolymers (copolymers) covering the encapsulated resin particles may be fused together.

  When printing on a recording medium such as plain paper or special paper for inkjet recording with ink using the encapsulated resin particles of the present invention, the encapsulated resin particles are more preferably formed at room temperature, and the colorant fixing property and printing In order to obtain good results with respect to the abrasion resistance and glossiness of the part, 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 even more preferably 10 ° C. or less. It is. Therefore, when the encapsulated resin particles of the present invention are used in an ink jet ink, it is preferable to design the glass transition temperature of the polymer (copolymer, copolymer) constituting the wall material to be 30 ° C. or lower. More preferably, it is designed to be 15 ° C. or lower, more preferably 10 ° C. or lower. However, if the glass transition temperature is lower than −20 ° C., the solvent resistance tends to decrease, so care must be taken.

Further, similarly to the polymer constituting the wall material, the Tg of the resin constituting the resin particles covered with the wall material can be arbitrarily controlled. Generally, a high Tg polymer (resin) is hard and brittle, whereas a low Tg polymer (resin) is soft and rich in toughness. Therefore, by utilizing such a relationship between Tg and polymer properties, the core (resin particles ) And the shell (wall material) can change the Tg of the constituent polymer (resin) to obtain encapsulated resin particles suitable for various applications. For example, when the Tg of the resin (polymer) constituting the resin particles is designed to be 30 ° C. or higher and the Tg of the resin (polymer) constituting the wall material is designed to be 10 ° C. or less, the wall material can provide good color material fixing properties While ensuring the film formability, the resin particles as the core can achieve both high scratch resistance of the printed portion. Alternatively, if the Tg of the resin that constitutes the resin particles is designed to be sufficiently lower than the Tg of the resin that constitutes the wall material, the film formability can be improved when printing on a recording medium having a large surface irregularity such as plain paper. And better results can be obtained with respect to glossiness.
[Aqueous resin emulsion]
Hereinafter, the aqueous resin emulsion of the present invention will be described.

  The aqueous resin emulsion of the present invention is an oil-in-water type (o / w type) emulsion in which the encapsulated resin particles described above are all or part of the dispersoid. The content of the encapsulated resin particles is not particularly limited, but is usually about 5 to 50% by weight with respect to the total weight of the aqueous resin emulsion.

  A preferred embodiment of the aqueous resin emulsion of the present invention includes an aqueous dispersion obtained after the polymerization reaction in the above-described method for producing encapsulated resin particles. By adding other components necessary for the inkjet recording pigment ink to this aqueous dispersion, the inkjet recording pigment ink of the present invention described later can be produced.

  The aqueous dispersion, which is one of the preferred embodiments of the aqueous resin emulsion of the present invention, contains not only the encapsulated resin particles but also the monomer (cationic polymerizable surfactant) used in the production of the encapsulated resin particles. Agent, a hydrophilic monomer, an ionic polymerizable surfactant, a hydrophobic monomer, etc.) that are derived from unreacted monomers (by-products such as monomers not used in the reaction and polymerizable compounds). Therefore, it is preferable to purify the aqueous dispersion to reduce the concentration of unreacted monomers. When the above-mentioned aqueous dispersion that has been purified is used as an ink for ink jet recording, it has high chroma and printing density (printing density) on plain paper, and the occurrence of bleeding is suppressed. Therefore, it is possible to output an image further having good glossiness with respect to an inkjet recording-dedicated medium, particularly an inkjet glossy medium.

  As a method for purifying the aqueous dispersion containing the encapsulated resin particles, a centrifugal separation method, an ultrafiltration method, or the like can be used.

The amount of the unreacted monomer contained in all components other than the solid content of the aqueous dispersion containing the encapsulated resin particles after the purification treatment is preferably 50,000 ppm or less, and preferably 10,000 ppm or less. More preferred. The amount of the unreacted monomer can be easily measured using a sample containing the unreacted monomer at a known concentration, using gas chromatography or liquid chromatography of the measurement sample.
[Pigment ink for inkjet recording]
Hereinafter, the pigment ink for inkjet recording of the present invention will be described.

  The pigment ink for inkjet recording of the present invention (hereinafter also referred to as an ink composition) contains at least the aqueous resin emulsion of the present invention having the above-described encapsulated resin particles as a dispersoid.

  The content of the encapsulated resin particles is preferably 1 to 20% by weight, more preferably 5 to 10% by weight, based on the total weight of the ink composition of the present invention. If the content of the encapsulated resin particles is less than 1% by weight, the effect of addition may not be sufficiently exhibited. Conversely, if the content exceeds 20% by weight, the viscosity of the ink becomes high, and the reliability such as clogging of the printer nozzles may occur. May cause sexual problems.

  The ink composition of the present invention contains a pigment as a coloring material. As the pigment, those usually used for ink for inkjet recording can be used without particular limitation, and examples thereof include the following inorganic pigments and organic pigments.

  Examples of inorganic pigments include carbon blacks (CI pigment black 7) such as furnace black, lamb black, acetylene black, and channel black, and iron oxide pigments. Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments), polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxanes). Pigments, thioindigo pigments, isoindolinone pigments, or quinofuranone pigments), dye chelates (eg, basic dye-type chelates or acidic dye-type chelates), nitro pigments, nitroso pigments, or aniline black. .

  More specifically, as an inorganic pigment used for black, the following carbon black, for example, No. manufactured by Mitsubishi Chemical Corporation is used. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, or No2200B, etc .; Columbia-made Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc .; 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc .; or Color Black FW1, Color Black FW2, Bck, Col Black FW2, Cck W200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, can be used Printex 140U, Special Black 6, Special Black 5, Special Black 4A, or Special Black 4 and the like.

  Moreover, as the organic pigment for black, a black organic pigment such as aniline black (CI Pigment Black 1) can be used.

  Examples of organic pigments for yellow ink include C.I. I. Pigment Yellow 1 (Hansa Yellow), 2, 3 (Hansa Yellow 10G), 4, 5 (Hansa Yellow 5G), 6, 7, 10, 11, 12, 13, 14, 16, 17, 24 (Flavantron Yellow) , 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108 (anthrapyrimidine yellow), 109, 110, 113, 117 ( Copper complex pigment), 120, 124, 128, 129, 133 (quinophthalone), 138, 139 (isoindolinone), 147, 151, 153 (nickel complex pigment), 154, 167, 172, 180, and the like. it can.

  Examples of organic pigments for magenta ink include C.I. I. Pigment Red 1 (Paral Red), 2, 3 (Toluidine Red), 4, 5 (lTR Red), 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21 , 22, 23, 30, 31, 32, 37, 38 (pyrazolone red), 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88 (thioindigo), 112 (Naphthol AS series), 114 (Naphthol AS series), 122 (Dimethylquinacridone), 123, 144, 146, 149, 150, 166, 168 (Antanthrone orange), 170 (Naphthol AS series), 171, 175, 176 , 177, 178, 179 (berylene maroon), 184, 185, 187, 202, 209 (dichloroquinacridone), 219, 224 (berylene), 245 (naphthol AS yarn) ) Or C.I. I. And CI pigment violet 19 (quinacridone), 23 (dioxazine violet), 32, 33, 36, 38, 43, and 50.

  Examples of organic pigments for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 15: 4, 16 (metal-free phthalocyanine), 18 (alkali blue toner), 22, 25, 60 ( Slen Blue), 65 (Biolantron), 66 (Indigo), C.I. I. Vat blue 4, 60 etc. can be mentioned.

  Examples of organic pigments used in color inks other than magenta, cyan or yellow ink include C.I. I. Pigment green 7 (phthalocyanine green), 10 (green gold), 36, 37; C.I. I. Pigment brown 3, 5, 25, 26; I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63, etc. can be used.

  The content of the pigment (coloring material) is preferably 1 to 10% by weight, more preferably 3 to 7%, based on the total weight of the ink composition of the present invention, from the viewpoint of the balance between image quality and ejection stability. % By weight.

  The solvent of the ink composition of the present invention preferably contains water and a water-soluble organic solvent as a basic solvent, and may contain any other component as necessary.

  Examples of the water-soluble organic solvent include C1-C4 alkyl alcohols such as ethanol, methanol, butanol, propanol, and isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and ethylene glycol monomethyl ether. Acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether , Triethylene glycol mono-n-butyl ether , Ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n- Propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, propylene glycol mono-n -Glycol ethers such as butyl ether or dipropylene glycol mono-n-butyl ether Alternatively, there may be mentioned formamide, acetamide, dimethyl sulfoxide, sorbitol, sorbitan, acetin, diacetin, triacetin, or sulfolane and the like.

  The ink composition of the present invention preferably contains a wetting agent composed of a high-boiling water-soluble organic solvent as one of the water-soluble organic solvents from the viewpoint of ensuring the water retention and wettability of the ink composition. . As such a high-boiling water-soluble organic solvent, a water-soluble organic solvent having a boiling point of 180 ° C. or higher can be exemplified.

  Specific examples of the water-soluble organic solvent (wetting agent) having a boiling point of 180 ° C. or higher include ethylene glycol, propylene glycol, diethylene glycol, pentamethylene glycol, trimethylene glycol, 2-butene-1,4-diol, 2-ethyl- 1,3-hexanediol, 2-methyl-2,4-pentanediol, tripropylene glycol monomethyl ether, dipropylene glycol monoethyl glycol, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol, triethylene Glycol monomethyl ether, tetraethylene glycol, triethylene glycol, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol Rumonomethyl ether, tripropylene glycol, polyethylene glycol having a molecular weight of 2000 or less, 1,3-propylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, Examples include 1,6-hexanediol, glycerin, mesoerythritol, and pentaerythritol. An organic solvent having a boiling point of 200 ° C. or higher is preferable. These can be used alone or as a mixture of two or more. Accordingly, it is possible to provide an ink for ink jet recording that maintains fluidity and redispersibility for a long time even when left in an open state (in a state where it is exposed to air at room temperature). Furthermore, nozzle clogging is less likely to occur during printing or during restart after printing interruption, and high ejection stability can be obtained.

  The content of the water-soluble organic solvent (including the high-boiling water-soluble organic solvent) is preferably 10 to 50% by weight, more preferably 10 to 30% by weight, based on the total weight of the ink composition of the present invention. is there.

  Further, the water-soluble organic solvent includes polar solvents such as 2-pyrrolidone, N-methylpyrrolidone, ε-caprolactam, dimethyl sulfoxide, sulfolane, morpholine, N-ethylmorpholine, 1,3-dimethyl-2-imidazolidinone. One or more of these may be selected and used. The addition of these polar solvents has an effect on dispersibility and can improve the ejection stability of ink.

  The content of these polar solvents is preferably 0.1% by weight to 20% by weight and more preferably 1% by weight to 10% by weight with respect to the total weight of the ink composition of the present invention.

  The ink composition of the present invention preferably contains a penetrant for the purpose of promoting the penetration of the aqueous solvent into the recording medium. By rapidly penetrating the aqueous solvent into the recording medium, it is possible to reliably obtain a recorded matter with less image bleeding. As such a penetrant, polyhydric alcohol alkyl ethers (also referred to as glycol ethers) and 1,2-alkyldiols are preferably used. Specifically, as the alkyl ether of polyhydric alcohol, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol mono- n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, ethylene glycol mono- t-butyl ether, diethylene glycol mono-t-butyl Ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene Glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, etc. It is done. Specific examples of the 1,2-alkyldiol include 1,2-pentanediol and 1,2-hexanediol. In addition to these, linear carbonization such as 1,3-propanediol, 1,4-butanediol 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, etc. It may be appropriately selected from hydrogen diols.

  In particular, in the ink composition of the present invention, as the penetrant, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, 1,2-pentanediol, 1,2-hexanediol. Is preferred.

  The content of these penetrants is preferably 1 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 penetrant is less than 1% by weight, the penetrability is not effective, and if it exceeds 20% by weight, problems such as a decrease in print quality due to image bleeding and an increase in viscosity occur. In particular, by using 1,2-alkyldiols such as 1,2-pentanediol and 1,2-hexanediol, the drying property and bleeding after printing are remarkably improved.

  In particular, by including glycerin in the ink composition of the present invention, ink clogging reliability and storage stability can be sufficiently ensured.

  Furthermore, since one or more compounds selected from the group consisting of alkyl ethers of polyhydric alcohols and 1,2-alkyl diols can be included, the permeability of the ink solvent component to the recording medium can be increased. Combined with the effect of the encapsulating resin particles of the invention, image blur can be drastically reduced even when printing on plain paper, recycled paper, etc., and the print quality can be greatly improved.

  Moreover, when using the above-mentioned glycol ethers, it is particularly preferable to use glycol ethers in combination with an acetylene glycol compound as a surfactant described later.

  The ink composition of the present invention preferably comprises a surfactant, particularly an anionic surfactant and / or a nonionic surfactant.

  Specific examples of anionic surfactants include alkane sulfonate, α-olefin sulfonate, alkylbenzene sulfonate, alkyl naphthalene sulfonic acid, acylmethyl tauric acid, dialkyl sulfosuccinic acid and other sulfonic acid types, alkyl sulfuric acid Ester salt, sulfated oil, sulfated olefin, polyoxyethylene alkyl ether sulfate ester salt; carboxylic acid type such as fatty acid salt, alkyl sarcosine salt; alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, And phosphoric acid ester type such as monoglycerite phosphoric acid ester salt; Specific examples of nonionic surfactants include ethylene oxide addition types such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amide; glycerin alkyl ester, sorbitan alkyl ester Polyol ester type such as sugar alkyl ester; polyether type such as polyhydric alcohol alkyl ether; alkanolamide type such as alkanolamine fatty acid amide.

  In particular, the ink composition of the present invention preferably contains an acetylene glycol surfactant and / or an acetylene alcohol surfactant as a surfactant. Thereby, the permeability of the aqueous solvent constituting the ink to the recording medium can be increased, and printing with less bleeding can be expected on various recording media.

  Preferred examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3ol and the like. Commercially available acetylene glycol surfactants include Surfinol 82, 104, 440, 465, 485, or TG (all available from Air Products and Chemicals. Inc.), Olphine STG, Olphine E1010 (trade name) ( As described above, Nissin Chemical Co., Ltd.) and the like are preferably used.

  Preferable examples of the acetylene alcohol surfactant include Surfynol 61 (available from Air Products and Chemicals. Inc.).

  The content of these surfactants is preferably in the range of 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total weight of the ink composition of the present invention.

  The ink composition of the present invention can contain a pH adjuster, and the pH is preferably set in the range of 7 to 11, more preferably in the range of 8 to 9.

  As a pH adjuster for setting the pH of the ink composition within such a range, a basic compound is preferably used. Specifically, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, carbonate Sodium hydrogen, potassium carbonate, lithium carbonate, sodium phosphate, potassium phosphate, lithium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium oxalate, potassium oxalate, lithium oxalate, sodium borate, four Alkali metal salts such as sodium borate, potassium hydrogen phthalate, and potassium hydrogen tartrate; ammonia; and methylamine, ethylamine, diethylamine, trimethylamine, triethylamine, tris (hydroxymethyl) aminomethane hydrochloride, triethanolamine, diethanolamine And amines such as dimethylamine, diethylethanolamine, triisopropenolamine, butyldiethanolamine, morpholine, and propanolamine.

  Among these, when an alkali hydroxide compound or an amine alcohol is added to the ink composition, the dispersion stability of the pigment particles having an anionic group in the ink can be improved.

  In addition, the ink composition of the present invention contains benzoic acid, dichlorophene, hexachlorophene, sorbic acid, p-hydroxybenzoic acid ester, ethylenediaminetetraacetic acid (EDTA), dehydro for the purpose of mold prevention, antiseptic or rust prevention. One or more kinds selected from sodium acetate, 1,2-benchazolin-3-one [product name: Proxel XL (manufactured by Avicia)], 3,4-isothiazoline-3-one, 4,4-dimethyloxazolidine and the like Compounds can be included.

  In addition, the ink composition of the present invention may contain at least one selected from the group consisting of urea, thiourea, and ethylene urea for the purpose of preventing the nozzles of the ink jet recording head from drying.

One example (embodiment example 1) of an embodiment of the ink composition of the present invention that is particularly preferred is an ink composition comprising at least all of the following (1) to (5).
(1) Pigment (coloring material)
(2) One or more compounds (penetrant) selected from the group consisting of the encapsulated resin particles (3) diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, and 1,2-alkyldiol having 4 to 10 carbon atoms.
(4) Glycerin (5) Water Another example (embodiment example 2) of the particularly preferred embodiment of the ink composition of the present invention is an ink composition containing at least all of the following (1) to (6).
(1) Pigment (coloring material)
(2) One or more compounds (penetrant) selected from the group consisting of the encapsulated resin particles (3) diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, and 1,2-alkyldiol having 4 to 10 carbon atoms.
(4) Acetylene glycol surfactant and / or acetylene alcohol surfactant,
(5) Glycerin (6) Water In each of the above embodiments, the amount added when the diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether of (3) is used as the penetrant is based on the total weight of the ink composition. It is preferably 10% by weight or less, and more preferably 0.5 to 5% by weight. By adding diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether to the ink composition, the penetrability of the ink composition into the recording medium can be improved, which helps to improve the print quality. Further, diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether also has an effect of improving the solubility of the acetylene glycol surfactant.

  In each of the above embodiment examples, the amount of addition in the case of using the C4-C10 1,2-alkyldiol of (3) as a penetrant is 15% by weight or less with respect to the total weight of the ink composition. Preferably there is. When a 1,2-alkyldiol having 3 or less carbon atoms is used, sufficient permeability of the ink composition to the recording medium cannot be obtained, and 1,2-alkyldiol having more than 15 carbon atoms dissolves in water. Since it becomes difficult, it is not preferable. Further, when the amount of 1,2-alkyldiol having 4 to 10 carbon atoms in the ink composition exceeds 15% by weight, the viscosity of the ink composition tends to increase, which is not preferable. Specifically, as the 1,2-alkyldiol having 4 to 10 carbon atoms, it is preferable to use 1,2-pentanediol or 1,2-hexanediol. Either one can be used alone, It can also be used together. 1,2-pentanediol is preferably added in an amount of 3 to 15% by weight based on the total weight of the ink composition. By adding 3% by weight or more of 1,2-pentanediol to the ink composition, an ink composition having good permeability can be obtained. 1,2-Hexanediol is preferably added in a range of 0.5 to 10% by weight with respect to the total weight of the ink composition, and an ink composition having good permeability can be obtained in the above range.

  In addition, when the ink composition of each of the above embodiment examples is used in an ink jet recording method, the solid wetting agent is added to the total weight of the ink composition so that clogging of the ink jet nozzle is less likely to occur (improvement of clogging reliability). It is preferable to make it contain in 3 to 20 weight% with respect to. The addition of the solid humectant is not limited to the embodiments described above, and can be added to all ink compositions using the encapsulated resin particles of the present invention.

The solid wetting agent refers to a water-soluble substance that is solid at room temperature (25 ° C.) and has a water retention function. Preferred solid wetting agents are saccharides, sugar alcohols, hyaluronate, trimethylolpropane, and 1,2,6-hexanetriol. Examples of sugars include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol. Sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like. Here, saccharide means saccharide in a broad sense, and is used to include substances that exist widely in nature, such as alginic acid, α-cyclodextrin, and cellulose. The derivatives of these saccharides are represented by reducing sugars of the saccharides (for example, sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugar (eg, aldonic acid, uronic acid, etc.), amino acid, thio sugar, etc.). Sugar alcohols are particularly preferred, and specific examples include maltitol, sorbitol, xylitol and the like. As the hyaluronate, a commercially available sodium hyaluronate 1% aqueous solution (molecular weight 350,000) can be used. Particularly preferred solid wetting agents are trimethylolpropane, 1,2,6-hexatriol, sugars, and sugar alcohols. One or more solid wetting agents can be added to the ink composition of the present invention.

  By including a solid wetting agent in the ink composition, it is possible to suppress water evaporation of the ink composition by its water retention function, so that the viscosity of the ink composition increases around the ink flow path and the inkjet nozzle of the inkjet printer. In addition, since it is difficult for the ink composition to form a film due to water evaporation, nozzle clogging is less likely to occur. In addition, since the solid wetting agent is chemically stable, the quality of the ink composition can be maintained over a long period of time without being decomposed in the ink composition. Even when the above-described solid wetting agent is added to the ink composition, the ink composition does not wet the nozzle plate, and the ink composition can be stably ejected from the inkjet nozzles. When the compound selected from trimethylolpropane, 1,2,6-hexanetriol, saccharides, and sugar alcohols is used as the solid moisturizing agent, the above-described effect is particularly excellent.

  The total amount of the solid wetting agent added to the ink composition of the present invention is preferably 3 to 20% by weight based on the total weight of the ink composition. More preferably it is. A preferred combination when two or more solid wetting agents are used in combination is selected from one or more selected from saccharides, sugar alcohols, and hyaluronates, trimethylolpropane, and 1,2,6-hexanetriol. A combination with one or more. When a solid wetting agent is added to the ink composition in this combination, an increase in the viscosity of the ink composition can be suppressed. By making the amount of the solid wetting agent contained in the ink composition 3% by weight or more, an effect of preventing clogging of the ink jet nozzle is obtained, and the amount of the solid wetting agent contained in the ink composition is 20% by weight. % Or less, the ink composition can be stably ejected from the ink jet nozzle, so that an ink composition having a sufficiently low viscosity can be obtained.

  In the above embodiment example 2, the acetylene glycol surfactant and / or acetylene alcohol surfactant (4) is added to the ink composition, and the total amount of these surfactants is the total amount of the ink composition. It is preferable that it is 0.01 to 10 weight% with respect to a weight, and it is especially preferable that it is 0.1 to 5 weight%.

  The ink compositions shown in the above embodiment examples are particularly excellent in pigment dispersion stability and ejection stability from an inkjet head nozzle when used in an inkjet recording method, and also clogged nozzles over a long period of time. And stable printing is possible. In addition, when the ink composition is printed on a recording medium such as plain paper, recycled paper, and coated paper, the drying property of the ink after printing is good, and there is no bleeding by using this ink composition. A high-quality image having a high printing density and excellent color developability can be obtained.

  The ink composition of the present invention is particularly preferable as an ink composition for use in an ink jet recording method, but its application is not limited.

  Further, the ink composition of the present invention containing the encapsulated resin particles of the present invention preferably further comprises a compound represented by the following general formula (2).

（式中、Ｒ₁、Ｒ₂はそれぞれ独立して炭素数１〜１０のアルキル基を表し、ｍ，ｎはそれぞれ繰り返し単位数であって、ｍ+ｎが平均で０〜１０である。）
上記一般式（２）の化合物において、Ｒ₁、Ｒ₂はそれぞれ独立して炭素数１〜１０のアルキル基であり、ｍ，ｎはそれぞれ繰り返し単位数であって、ｍ＋ｎが平均で０〜１０であるが、普通紙上ではよりにじみが少なく高発色であり、専用紙上では十分な発色に加えて定着性を有するインク組成物を作製可能であり、インクジェット記録にあってはさらに吐出安定性が優れ、印字における十分な線幅が確保できる水性インク組成物を得るためには、Ｒ₁＋Ｒ₂の炭素数は好ましくは５以上１５以下であり、ｍ＋ｎは好ましくは０〜７の範囲である。

(In the formula, R ₁ and R ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, m and n are respectively the number of repeating units, and m + n is 0 to 10 on average.)
In the compound of the general formula (2), R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms, m and n are the number of repeating units, and m + n is 0 to 10 on average. However, it is less bleed on plain paper and has high color development, and on special paper, it is possible to produce an ink composition that has fixing properties in addition to sufficient color development, and in ink jet recording, it has excellent ejection stability. In order to obtain a water-based ink composition capable of securing a sufficient line width in printing, the carbon number of R ₁ + R ₂ is preferably 5 or more and 15 or less, and m + n is preferably in the range of 0-7.

  The content of the compound of the general formula (2) is preferably 0.1 to 20% by weight, more preferably 0.3 to 10% by weight, based on the total weight of the ink composition. In order to obtain particularly good glossiness and image clarity, 0.5 to 10% by weight is preferable.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples.
“Production of resin particles“ P1 ”having an anionic group on the surface”
After adding and stirring 40 g of dicyclopentenyloxyethyl methacrylate to 600 g of ion-exchanged water, 10 g of anionic polymerizable surfactant Aqualon KH-10 previously dissolved in 80 g of ion-exchanged water was added and stirred. Mixed. After adjusting the pH to 8 with a 1 mol / l potassium hydroxide aqueous solution, the solution 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 solution of potassium persulfate dissolved in 1 g of potassium persulfate as a polymerization initiator was added dropwise to 100 g of ion exchange water, and polymerization was performed at 80 ° C. for 6 hours while introducing nitrogen. did. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l aqueous potassium hydroxide solution. Subsequently, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device to obtain an emulsion of resin particles “P1” (particle base) having a sulfone group (anionic group) on the surface.
"Production of resin particles" P2 "having an anionic group on the surface"
In the above-mentioned “manufacture of resin particles“ P1 ”having an anionic group on the surface”, except that “dicyclopentenyloxyethyl methacrylate 40 g” is replaced with “n-butyl methacrylate 40 g”, An emulsion of resin particles “P2” (particle base) having a sulfone group (anionic group) was obtained.
“Manufacture of encapsulated resin particle dispersions“ M1 ”to“ M3 ””
Using the resin particles “P1” and “P2” (resin particles having an anionic group on the surface) produced as described above, encapsulated resin particle dispersions “M1” to “M3” are prepared as follows. Manufactured. Encapsulated resin particle dispersions “M1” to “M3” are examples of the aqueous resin emulsion of the present invention.
"Manufacture of encapsulated resin particle dispersion" M1 ""
To 400 g of the resin particle “P1” emulsion (solid content concentration: about 12%), 300 g of ion-exchanged water and 1.25 g of dimethylaminoethyl methacrylate methacrylate as a cationic polymerizable surfactant were added and mixed. Next, 16 g of lauryl methacrylate and 4 g of isobornyl methacrylate were added, stirred and mixed, and 9.1 g of anionic polymerizable surfactant Aqualon KH-10 previously dissolved in 50 g of ion-exchanged water was used as a hydrophilic monomer. 0.5 g of 2-acrylamido-2-methylpropanesulfonic acid was added and stirred and mixed. After adjusting the pH to 8 with a 1 mol / l potassium hydroxide aqueous solution, the solution 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 0.4 g of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 40 g of ion-exchanged water. Polymerized for hours. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l aqueous potassium hydroxide solution. Next, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device, to obtain a target encapsulated resin particle dispersion “M1”.
"Production of encapsulated resin particle dispersion" M2 ""
In “Production of encapsulated resin particle dispersion“ M1 ””, “400 g of emulsion of resin particles“ P1 ”(solid content concentration of about 12%)” is changed to 400 g of emulsion of resin particles “P2” (solid content concentration of about 12%). %)), And the target encapsulated resin particle dispersion “M2” was obtained by the same treatment method.
"Production of encapsulated resin particle dispersion" M3 ""
To 400 g of the resin particle “P1” emulsion (solid content concentration: about 12%), 300 g of ion-exchanged water and 1.25 g of dimethylaminoethyl methacrylate methacrylate as a cationic polymerizable surfactant were added and mixed. Next, 4 g of lauryl methacrylate and 16 g of isobornyl methacrylate were added, stirred and mixed. 0.5 g of 2-acrylamido-2-methylpropanesulfonic acid was added and stirred and mixed. After adjusting the pH to 8 with a 1 mol / l potassium hydroxide aqueous solution, the solution 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 0.4 g of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 40 g of ion exchange water, and nitrogen was introduced at 80 ° C. for 6 hours. Polymerized for hours. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l aqueous potassium hydroxide solution. Next, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device, to obtain a target encapsulated resin particle dispersion “M3”.

  The volume average particle diameter (diameter) of the encapsulated resin particles in the obtained encapsulated resin particle dispersion was measured using a laser Doppler type particle size distribution analyzer Microtrac UPA150 manufactured by Leeds & Northrop. The results are shown in Table 1 below.

  As is clear from Table 1 below, the encapsulated resin particles of Examples 1 to 3 are each formed with a wall material having a constant layer thickness with respect to the particle base (resin particles), which becomes the core. It can be seen that the resin particles and the wall material serving as the shell form a clearly separated and independent core-shell structure.

Resin particles having an anionic group on the surface are dispersed in an aqueous solvent and coexist with the cationic hydrophilic monomer and / or the cationic polymerizable surfactant and the anionic polymerizable surfactant. It is a schematic diagram which shows a state. FIG. 2 is a schematic diagram showing a state in which a cationic hydrophilic monomer and / or a cationic polymerizable surfactant and an anionic polymerizable surfactant are polymerized in the dispersed state shown in FIG. 1.

Explanation of symbols

1 pigment particle, 2 cationic hydrophilic monomer and / or cationic polymerizable surfactant, 3 anionic polymerizable surfactant, 11 cationic group, 12, 12 ′ hydrophobic group, 13, 13 ′ polymerizable group , 14, 14 'anionic group, 60' wall material, 100 'encapsulated resin particles

Claims (6)

Resin particles having an anionic group on the surface are encapsulated resin particles coated with a wall material mainly composed of a polymer,
The polymer is a repeating structural unit derived from “a cationic polymerizable surfactant having a cationic group, a hydrophobic group and a polymerizable group” and / or “a hydrophilic monomer having a cationic group”, “ An encapsulated resin particle containing at least a repeating structural unit derived from an “ionic polymerizable surfactant having an ionic group, a hydrophobic group, and a polymerizable group”.   After the cationic polymerizable surfactant and / or the hydrophilic monomer and the ionic polymerizable surfactant are sequentially added and mixed in this order to the aqueous dispersion of the resin particles, a polymerization initiator is added. The encapsulated resin particles according to claim 1, which are produced by adding a polymer to polymerize them.   The encapsulated resin particle according to claim 1, wherein the polymer further contains a repeating structural unit derived from a hydrophobic monomer. 2. The polymer further comprises one or more selected from the group consisting of 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 resin particle according to any one of?

[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 aqueous resin emulsion in which the encapsulated resin particles according to any one of claims 1 to 4 are all or part of a dispersoid. A pigment ink for inkjet recording, comprising the aqueous resin emulsion according to claim 5.

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