JP2007197633A - Polymer particle dispersion, method for producing the same, and display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inexpensively producing a polymer particle dispersion in which the polymer particles of from nano-level to micro-level are dispersed while reducing the number of steps. <P>SOLUTION: The method for producing the polymer particle dispersion in which polymer particles are dispersed in a 14-30C aliphatic hydrocarbon solvent (an organic solvent A) is a nonaqueous emulsion dispersion method using the organic solvent A and an organic solvent B having 9.0-10.0 solubility parameter and having almost no compatibility with the organic solvent A, and comprises dissolving a monomer which has two or more (meth)acryloyl groups in one molecule, and which can be dissolved in the organic solvent B but cannot be dissolved in the organic solvent A, in the organic solvent B, or optionally simultaneously adding a resin which can be dissolved in the organic solvent B but cannot be dissolved in the organic solvent A thereto, to provide a disperse phase solution, dispersing a polymerization initiator in the organic solvent A to provide a dispersion comprising a disperse phase of the disperse phase solution and a continuous phase of the organic solvent A, crosslinking the monomer or the monomer and the resin by light or heat, and removing the organic solvent B from the dispersion by pressure reduction or heating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for producing a polymer particle dispersion in which oil / oil emulsification dispersion is performed using two or more organic solvents having little compatibility, and a polymer particle dispersion obtained by the method.
According to the production method of the present invention, a polymer particle dispersion in which nano-level to micro-level polymer particles are stably dispersed in a nonpolar organic solvent can be obtained. More specifically, in the present invention, an aliphatic hydrocarbon solvent having 14 to 30 carbon atoms (hereinafter referred to as organic solvent A) and an sp value of 9.0 to 10.0 (cal · cm ⁻³ ) ^1/2 And a polar solvent having little compatibility with the organic solvent A is used. Further, a polymerization initiator that dissolves a single polyfunctional monomer in the organic solvent B or simultaneously contains a resin that can be dissolved in the organic solvent B but not in the organic solvent A, and further generates a radical by light or heat. The dissolved and encapsulated material is dispersed in the organic solvent A to be a continuous phase, and then a crosslinking reaction is caused by light or heat, and the organic solvent B is removed by decompression or heating, whereby the polymer particles are removed from the organic solvent. A polymer particle dispersion stably dispersed in A is obtained. Further, the present invention provides the above-described production method, wherein a colored material is further encapsulated in the organic solvent B to form a composite, whereby the nano-level to micro-level colored polymer composite particles are contained in the organic solvent A which is a nonpolar solvent. The present invention relates to a method for producing a colored polymer composite particle dispersion in which is stably dispersed, and a colored polymer composite particle dispersion obtained by the method. Furthermore, the present invention relates to a liquid toner, colored particles for electrophoretic display elements, and colored particles for electronic paper using the colored polymer composite particle dispersion prepared above.

In recent years, with the spread of networks, documents distributed in the form of printed materials so far have been distributed as electronic documents. In order to view these electronic documents, it has been possible to obtain information from a CRT (Cathode Ray Tube) or LCD (Liquid Crystal Display) and an ELD (Electroluminescence Display). It has been pointed out that if you keep looking at the time, the human body is extremely fatigued for ergonomic reasons and cannot be seen for a long time. In order to solve these problems, what is called a paper-like display or electronic paper has recently been intensively studied (for example, Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3).
The method for producing colored electrophoretic particles for capsule electrophoretic display elements is similar to the technique for producing liquid toner, for example, particles of colored particles (such as titanium oxide or carbon black) in a highly volatile organic solvent. A monomer having a long-chain alkyl group on the surface is graft-polymerized, and then the colored particles are taken out with a centrifuge and dried and washed several times to take out the colored particles as powder. Thereafter, it is mixed and dispersed in an insulating solvent applied to the electrophoretic display element with a dispersant, a charge adjusting agent and the like. As described above, the conventional method has a problem that it takes a long time and costs to obtain colored particles.
(For example, see Patent Document 1, Non-Patent Document 4, and Non-Patent Document 5.)

Takashi Kitamura; Color material, 74 (6), pp303-307 (2001) "Digital imaging technology" Hideyuki Kawai et al .; Industrial Materials, 48 (2) pp38-41 (2000) "Electrophoretic Display" Takahashi Yasuki; Science and Industry, 78 (7), pp361-368 (2004) "The ultimate device of" paper + display "= electronic paper" US Patent Application Publication No. 2002/0185378 Tsubokawa Norio: Journal of Japan Rubber Association, 70 (7) pp378-385 (1997) Nakanishi Kazuko: Tojo Synthetic Research Annual Report, 7, pp46-49 (2004)

  The present invention provides a method for producing nano-level to micro-level particle synthesis with a reduced number of steps and at low cost, and further a polyfunctional monomer and a polymerization initiator that generates radicals by light or heat. Is used to improve solvent resistance and strength against physical energy. In addition, the present invention relates to a coating material for various uses including ink and toner for copying, a coloring material for liquid crystal and a color filter for portable terminals, which has been increasingly demanded for full color in recent years, and an electronic for which full color is desired. It is an object of the present invention to provide a polymer particle dispersion suitably used as a coloring material for books and rewritable paper (electronic paper).

  In view of the above-described present situation, the present inventors have conducted intensive research to solve the above-described problems. As a result, oil / oil emulsification or suspension dispersion is performed using two or more organic solvents having little compatibility. In the method, by using a polar organic solvent having a lower boiling point than the nonpolar organic solvent forming the continuous phase as the organic solvent B of the dispersed phase, the organic solvent B can be easily removed from the dispersed phase by reduced pressure or heating. It was found that a polymer particle dispersion in which nano-level to micro-level polymer particles are stably dispersed in the remaining organic solvent A in the continuous phase can be obtained. Based on this finding, the inventors have completed the present invention.

In the present invention, [1] an aliphatic hydrocarbon solvent having 14 to 30 carbon atoms (hereinafter referred to as organic solvent A) and a solubility parameter (hereinafter referred to as sp value) of 9.0 to 10.0 (cal · cm ⁻³ ) A non-aqueous emulsification dispersion method using an organic solvent B which is ^1/2 and hardly compatible with the organic solvent A, and can be dissolved in the organic solvent B but not in the organic solvent A 1 A monomer having two or more (meth) acryloyl groups in the molecule (hereinafter referred to as a polyfunctional monomer) is dissolved, or a resin that is simultaneously soluble in the organic solvent B and not dissolved in the organic solvent A is contained. Alternatively, a polymerization initiator that generates radicals by heat is dissolved to obtain a dispersed phase solution, and the dispersed phase solution is dispersed in the organic solvent A to obtain a dispersion composed of the dispersed phase of the dispersed phase solution and the continuous phase of the organic solvent A. After, by light or heat The present invention relates to a method for producing a polymer particle dispersion obtained by dispersing polymer particles in an organic solvent A, wherein a crosslinking reaction is caused and the organic solvent B is removed from the dispersion liquid under reduced pressure or by heating.
The present invention also relates to [2] the method for producing a polymer particle dispersion according to the above [1], wherein the organic solvent B is a polar solvent having a boiling point lower than that of the organic solvent A and a higher evaporation rate.

In the present invention, [3] The dispersed phase solution can dissolve the polyfunctional monomer alone in the organic solvent B, or can simultaneously contain the resin, and can be dissolved or dispersed in the organic solvent B. And [2], wherein the polymer particle dispersion is a colored polymer composite particle dispersion dispersed in the organic solvent A. ] The manufacturing method of the polymer particle dispersion of description.
The present invention also relates to [4] the method for producing a polymer particle dispersion according to any one of [1] to [3] above, wherein the average particle diameter is 10 nm to 100 μm.
[5] The polymer particle dispersion according to [3], wherein the coloring material is a solid selected from any one or more of a dye, an inorganic pigment, and an organic pigment. It relates to the manufacturing method.
The present invention also relates to [6] the method for producing a polymer particle dispersion according to any one of [1] to [3] above, wherein the resin is a resin having a negatively dissociating polar group.
The present invention also relates to [7] the method for producing a polymer particle dispersion according to any one of [1] to [3] above, wherein the resin has a positively dissociating polar group.
The present invention also relates to [8] a polymer particle dispersion obtained by the method for producing a polymer particle dispersion described in any one of [1] to [7].

The present invention also relates to [9] a liquid toner using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion described in any one of [1] to [7].
The present invention also relates to [10] a display element using polymer particles obtained by the method for producing a polymer particle dispersion described in any one of [1] to [7].
The present invention also provides [11] coloring for electrophoretic display elements using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion described in any one of [1] to [7]. Concerning particles.
The present invention also relates to [12] colored particles for electronic paper using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion described in any one of [1] to [7]. .
Here, the reason why the electrophoretic display element is distinguished from the electronic paper is that the electrophoretic display element is one of the displays in the electronic paper, and the colored polymer composite particles obtained in the present invention are electrophoretic display. This is because it is considered to be applicable to a display element other than the element (for example, a granular material or a toner display).

  According to the method for producing a polymer particle dispersion of the present invention, a polymer particle dispersion in which nano-level to micro-level polymer particles are stably dispersed in a nonpolar organic solvent can be produced at low cost with a small number of steps. Can be manufactured. In addition, according to the present invention, an inexpensive and environmentally friendly colored polymer composite particle dispersion in which nano-level to micro-level polymer particles to which a coloring material is fixed is stably dispersed can be obtained at low cost with fewer steps. Can be manufactured. Furthermore, the polymer particles and colored polymer composite particles obtained in the present invention are particles crosslinked with a polyfunctional monomer and a polymerization initiator that generates radicals by light or heat, and are resistant to solvent and physical energy. It has high resistance to it. The colored polymer composite particle dispersion, and the colored polymer composite particles in the dispersion are used for liquid crystals and mobile phones in which the demand for inks, copying toners, paints for various uses, and in recent years the demand for full color has increased dramatically. It can be used as a coloring material for a terminal color filter, or as a coloring material for an electronic book or rewritable paper (electronic paper) for which full color is desired.

  Hereinafter, the present invention will be described in detail based on embodiments.

In the present invention, an aliphatic hydrocarbon having 14 to 30 carbon atoms (hereinafter referred to as organic solvent A) and a solubility parameter (hereinafter referred to as sp value) of 9.0 to 10.0 (cal · cm ⁻³ ) ^1/2 There is a non-aqueous emulsification dispersion method using an organic solvent B which is a nonpolar solvent which is almost incompatible with the organic solvent A and has a lower boiling point than the organic solvent A. Dispersible resin that does not dissolve in organic solvent A, a polyfunctional monomer, and a polymerization initiator that generates radicals by light or heat are used to form a dispersed phase solution, and the dispersed phase solution is dispersed in organic solvent A to obtain a dispersed phase solution. An organic solvent A, characterized in that after forming a dispersion composed of a continuous phase of the organic solvent A and an organic solvent A, a crosslinking reaction is caused by light or heat, and the organic solvent B is removed from the dispersion by reduced pressure or heating. Polymer particles are dispersed inside A process for producing a polymer particle dispersion comprising Te.

In the method for producing a polymer particle dispersion of the present invention, a colored material is further encapsulated in an organic solvent B to form a composite, thereby obtaining a colored polymer composite particle dispersion in which the colored material is fixed to the polymer particles. be able to.
That is, in the present invention, the dispersed phase solution contains the resin and a coloring material that can be dissolved or dispersed in the organic solvent B but not dissolved in the organic solvent A in the organic solvent B. In the method for producing a polymer particle dispersion, the polymer particle dispersion is a colored polymer composite particle dispersion dispersed in an organic solvent A.
In addition, the present invention is the method for producing a polymer particle dispersion described above, wherein the colored polymer composite particles have an average particle size of 10 nm to 100 μm.

Moreover, this invention is a manufacturing method of said polymer particle dispersion whose sp value of the organic solvent B is 9.0-10.0 (cal * cm < ^-3 >) < ^1/2 >.
In the present invention, the Tg (glass transition temperature) of the resin is not limited, contains a polyfunctional monomer and a polymerization initiator that generates radicals by light or heat, and the coloring material is a dye, an organic pigment, or an inorganic pigment. It is a manufacturing method of said polymer particle dispersion.
Moreover, this invention is a manufacturing method of said polymer particle dispersion whose resin is resin which has a polar group dissociating negatively or positively.
Further, the present invention is a polymer particle dispersion or a colored polymer composite particle dispersion obtained by any one of the methods described above.
In the present invention, the colored polymer composite particles obtained by any one of the methods described above are used for a liquid toner such as an ink jet.
In the present invention, the colored polymer composite particles obtained by any of the above methods are used as colored particles for electrophoretic display elements.
In the present invention, the colored polymer composite particles obtained by any one of the above methods are used as colored particles for electronic paper.

The oil / oil (O / O) dispersion method (suspension dispersion or emulsification dispersion) employed in the production method of the polymer particle dispersion of the present invention is a polar solvent as the organic solvent A that is almost incompatible with the organic solvent B. Is used. Here, the fact that the organic solvent A and the organic solvent B are almost incompatible means that the organic solvent A and the organic solvent B are phase-separated visually. In the case of producing a polymer particle dispersion (or colored polymer composite particle dispersion) used for electrophoretic display such as electronic paper, it becomes a carrier liquid.
As the organic solvent A, it is preferable to use a linear or branched aliphatic hydrocarbon having an electric resistance of 10 ⁹ Ω or more and a dielectric constant of 10 or less. For example, it is an aliphatic hydrocarbon having 14 to 30 carbon atoms, such as tetradecane, hexadecane, octadecane, and squalane. Although there is a possibility of mixing with the organic solvent B depending on the dispersion atmosphere, it can be used if it is slightly mixed and can be emulsified and dispersed. Moreover, since the miscibility of the organic solvent A and the organic solvent B depends on the temperature, by limiting the environment, that is, the temperature at which the organic solvent B can be emulsified or suspended in the organic solvent A. It can be used by adjusting to the range.

Since the compatibility of the organic solvent A and the organic solvent B of the aliphatic hydrocarbon depends on the temperature, when the compatibility is reduced as much as possible, emulsification or suspension dispersion is performed at a low temperature, for example, 10 ° C. or less. To do.
The organic solvent A is used as a continuous phase in the dispersion (suspension or emulsion).

The organic solvent B has an sp value of 9.0 to 10.0 (cal · cm ⁻³ ) ^1/2 , is hardly compatible with the organic solvent A, and has a lower boiling point than the organic solvent A. Any solvent can be used without particular limitation. For example, the boiling point of the organic solvent B is desirably 10 ° C. or higher, preferably 20 ° C. or higher, more preferably 30 ° C. or lower, than the organic solvent A. When the difference in boiling points is less than 10 ° C., when the organic solvent B is removed under reduced pressure, the organic solvent A may be removed at the same time, which may reduce the dispersion stability. Further, as the organic solvent B, it is preferable to use an organic solvent having a higher evaporation rate than the organic solvent A. For example, when the boiling point difference between the organic solvent A and the organic solvent B is close, it is desirable to use an organic solvent B having a higher evaporation rate than the organic solvent A. Thereby, when removing the organic solvent B by pressure reduction or heating, it can prevent that the organic solvent A is removed simultaneously.
As the organic solvent B, acetone is preferable. The organic solvent B is used as a solvent for the dispersed phase, that is, the reaction phase in the dispersion.

The organic solvents A and B may be used one by one. For example, for the organic solvent B, the solubility in the organic solvent B such as a polymerizable monomer, resin, oligomer, and dispersing agent described later is improved. Two or more solvents of the same system may be used (for example, a combination of tetradecane and octadecane in organic solvent A, and a combination of lower alcohol and acetone in organic solvent B). However, when using an organic solvent that can be determined that the continuous phase and the reaction phase are visually compatible, the stability of emulsification / suspension dispersion may be impaired.
The amount of the organic solvent B used is preferably 1 to 80% by weight and more preferably 2 to 70% by weight when the total amount of the organic solvent B and the organic solvent A mixed is 100% by weight.

  Further, a dispersant may be dissolved and dispersed in the organic solvent A in order to stabilize the synthesized oil droplets (polymer particles or colored polymer composite particle dispersion).

The dispersant is not particularly limited as long as it is dissolved in the organic solvent A. However, it is necessary to use an acidic dispersant and a basic dispersant properly depending on the surface state of the polymer particles to be formed. According to the investigation results of the dispersant, Solsperse 17000 (trade name, manufactured by Nippon Lubrizol Co., Ltd., basic dispersant), Solplus K210 (trade name, Nippon Lubrizol Corp., basic dispersant) and Solsperse 3000 (product) Name, Nippon Lubrizol Co., Ltd., acidic dispersant) showed particularly good dispersibility. However, it is necessary to examine the surface / interface state of the particles to be synthesized, and also to optimize depending on the application. Therefore, the molecular weight and the monomer composition are not particularly limited. The addition amount of these dispersants is 0.01 to 60% by weight with respect to the organic solvent A, more preferably 0.05 to 50% by weight, and particularly preferably 0.1 to 45% by weight.
Further, the dispersant may be dissolved and dispersed in the organic solvent B. In this case, the material is not particularly limited as long as the material can stably disperse a coloring material (for example, an organic pigment or an inorganic pigment) in the dispersed phase using the organic solvent B.

The resin used in the present invention is not particularly limited as long as it is a resin that dissolves in the organic solvent B used in the dispersed phase and does not dissolve in the organic solvent A. Depending on the use of the polymer particle dispersion or the colored polymer composite particle dispersion, a resin or oligomer having necessary characteristics can be used.
For example, by using a resin having a negatively dissociating polar group or a resin having a positively dissociating polar group, polymer particles or colored polymer composite particles having negative charges or positive charges can be formed. it can. The resin having an extremely positive group that dissociates negatively or positively can be obtained, for example, by homopolymerization of a monomer having a polar group that dissociates negatively or positively, or copolymerization of the monomer with another monomer.

  Examples of the resin having a polar group dissociating into a negative charge include a styrene-maleic acid half ester resin, an acrylate or methacrylate resin having a carboxyl group, an acrylate or methacrylate resin having a hydroxyl group, and an acrylate having a carboxyl group and a hydroxyl group. Or a methacrylate resin etc. are mentioned. Further, polymers soluble in acetone such as homopolymers such as styrene and methyl methacrylate can be used.

Further, as a resin having a polar group that dissociates into a positive charge, for example, polyvinylpyrrolidone, a CMS derivative obtained by adding a quaternary ammonium salt to a chloromethyl group (trade name: QBm manufactured by Seimi Chemical Co., Ltd.), or 1-ethyl-2-methyl- A resin copolymerized with a monomer having an unsaturated double bond capable of copolymerizing a cationic monomer such as 5-vinylpyrrolidone bromide can be used.
These resins may be used alone or in combination of two or more. Moreover, you may use together the monomer, oligomer, etc. which can be polymerized as needed.

The molecular weight of the resin used in the present invention is not particularly limited, but is preferably 1,000 to 100,000, particularly preferably 1,000 to 50,000 in terms of weight average molecular weight from the viewpoint of emulsion dispersion stability. Further, the Tg (glass transition temperature) of the resin is not particularly limited, but considering the stability of the particles after the removal of the organic solvent B, the Tg (glass transition temperature) is preferably 20 ° C. or higher, and more preferably 25 ° C. or higher. Preferably, 30 degreeC or more is especially preferable. For example, the Tg of the resin is preferably 20 to 150 ° C, particularly preferably 40 to 150 ° C. When Tg is lower than 20 ° C. (room temperature), it does not solidify at 20 ° C. (room temperature) and is in a liquid state, so that the generated particles do not solidify and may remain in the form of oil droplets to some extent.
The amount of these resins or oligomers added to the organic solvent B is preferably 0.5 to 90% by weight, more preferably 1 to 88% by weight, more preferably 2% by weight with respect to the organic solvent B to be dissolved. To 80% by weight is more preferred. If it is less than 0.5% by weight, there is a possibility that the composite of the coloring materials to be mixed at the same time becomes incomplete. On the other hand, when it is more than 90% by weight, the liquid viscosity of the reaction phase is high and the amount of the organic solvent B is small, so that the emulsified / suspended dispersion state may become unstable.

The polyfunctional monomer used in the present invention is a monomer having two or more (meth) acryloyl groups in one molecule. Examples of the polyfunctional (meth) acryloyl monomer include bisphenol F-type EO-modified di (meth). Acrylate, bisphenol A type EO-modified di (meth) acrylate, propylene glycol-based di (meth) acrylate, ethylene glycol-based di (meth) acrylate, isocyanuric acid EO-modified di (meth) acrylate, pentaerythritol di (meth) acrylate monosteare And monomers having a bifunctional group such as a rate.
Examples of the monomer having three or more (meth) acryloyl groups in one molecule include pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane PO-modified tri (meth) acrylate, and trimethylol. Propane EO-modified tri (meth) acrylate, isocyanuric acid EO-modified tri (meth) acrylate, dipentaerythritol pentaacrylate and hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. Examples thereof include monomers having a functional group. Here, EO represents ethylene oxide, PO represents propylene oxide, and the (meth) acryloyl group represents a methacryloyl group, an acryloyl group, and a mixture thereof.

  By using a monomer having two or more (meth) acryloyl groups in one molecule, polymer particles having a three-dimensional crosslinked structure can be formed, and particles having excellent solvent resistance can be obtained.

  The addition amount of the polymerizable monomer is preferably 0.1 to 90% by weight, more preferably 0.5 to 85% by weight, and particularly preferably 1 to 80% by weight with respect to the organic solvent B. When the amount is less than 0.1% by weight, the resulting polymer particles have low resistance to various solvents and are dissolved or swelled, resulting in incomplete polymer particles or colored polymer composite particles. Tend to be. When added over 90% by weight, the viscosity becomes too high, and the emulsification / suspension dispersion stability may become unstable.

  The polymerization initiator used in the present invention is appropriately selected and used depending on the type of polymerizable monomer of the reaction material. For example, in the case of a monomer capable of vinyl polymerization, a photopolymerization initiator that initiates polymerization by light and a thermal polymerization initiator that initiates polymerization by heat are suitable.

  The photopolymerization initiator is not particularly limited, and examples thereof include benzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, benzyl, and 2,2-diethoxy. Acetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutyl phenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholino-1-propanone, t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-na Toquinone, 9,10-phenanthraquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, etc. It is done. These photopolymerization initiators can be used alone or in combination of two or more.

  The thermal polymerization initiator is not particularly limited, and examples thereof include 2-cyano-2-propylazoformamide, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-amidinopropane). ) Dihydrochloride, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanovaleric acid), dimethyl 2,2′-azobisisobutyrate, 2,2′-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-a Bis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2′-azobis (2-methylpropionamidoxime), 2,2′-azobis [N- (2-carboxy An azonitrile compound such as ethyl) -2-methylpropionamide] and / or a cyclic azoamidine compound and / or an azoamide compound, and organic peroxides are used.

  The addition amount of the polymerization initiator such as photo / thermal polymerization initiator is 0.01 to 10% by weight, preferably 0.01 to 9% by weight, based on the polymerizable monomer. Particularly preferred is 0.01 to 8% by weight.

  When the addition amount is less than 0.01% by weight, the polymerization may be insufficient. For example, when a crosslinking reaction is performed, the curing is insufficient, and polymer particles having a crosslinked structure (for example, colored polymer) The chemical resistance of the composite particles) may be reduced. When it exceeds 10% by weight, the resulting polymer particles (for example, colored polymer composite particles) have a low molecular weight and may become brittle.

  By adding a coloring material in the organic solvent B, polymer particles colored in various colors can be obtained. The type of the coloring material is not particularly limited as long as it is dissolved or dispersed in the organic solvent B and is not dissolved in the organic solvent A. In the present invention, as the coloring material, both dyes and pigments can be used, but pigments are preferred in view of heat resistance and light resistance. Usable dyes include those soluble in organic solvents, such as metal complex dyes such as Spisol Yellow 7040, Spisol Red 7345, Spisol Black 7970, and cyanine dyes such as Oil Blue 5511 (trade name: Arimoto Chemical Industry). Product).

The pigment includes inorganic pigments and organic pigments, and both can be used. Examples of the organic pigment include azo, phthalocyanine, indigo, anthraquinone, perylene, quinacridone, methine / azomethine, and isoindolinone.
For the red coloring material, a single red pigment system may be used, or a yellow pigment system may be mixed with a red pigment system to perform toning. Examples of the red pigment system include Pigment Red 9, 122, 123, 146, 155, 168, 177, 180, 217, 220, 224, 254, and the like by color index name.

  Examples of yellow pigments include, for example, pigment yellow 17, 20, 24, 74, 83, 93, 109, 110, 117, 125, 128, 129, 138, 139, 147, 154 by color index name. It is done. Two or more of these red and yellow pigments can be mixed and used. Further, when a mixture of a red pigment system and a yellow pigment system is used, it is preferable to use the yellow pigment system at 90 parts by weight or less with respect to 100 parts by weight of the total amount of the red pigment system and the yellow pigment system.

  As the green coloring material, a single green pigment system may be used, or a yellow pigment system may be mixed with a green pigment system to perform toning. Examples of the green pigment system include Pigment Green 7, 36, and 37 by the color index name. Examples of yellow pigments include, for example, pigment yellow 17, 20, 24, 74, 83, 93, 109, 110, 117, 125, 128, 129, 138, 139, 147, 154 by color index name. It is done. Two or more of these green and yellow pigments can be mixed and used. When a green pigment system and a yellow pigment system are mixed and used, it is preferable to use the yellow pigment system at 90 parts by weight or less with respect to 100 parts by weight of the total amount of the green pigment system and the yellow pigment system.

For the blue coloring material, a single blue pigment system may be used, or a purple pigment system may be mixed with a blue pigment system to perform toning. Examples of the blue pigment system include pigment blue 15, 15: 3, 15: 4, 15: 6, 22, 60, and the like by color index name. Examples of purple pigments include pigment violet 19, 23, 29, 37, 50, etc. by color index name. These blue and purple pigments can be used in combination of two or more. When a blue pigment system and a violet pigment system are used in combination, the violet pigment system is preferably used in an amount of 90 parts by weight or less based on 100 parts by weight of the total amount of the blue pigment system and the violet pigment system.
Furthermore, for the purpose of improving the dispersion stability in the organic solvent B, pigment derivatives suitable for each can be used as appropriate.

As the black coloring material, for example, black pigments such as carbon black, graphite, titanium carbon, black iron oxide, manganese dioxide, and metal composite oxide are used.
As the white coloring material, for example, a white inorganic pigment having a high refractive index such as titanium oxide or germanium oxide is used. Furthermore, polymer particles having a refractive index of about 1.6 to 1.8 can be used. In addition, polymer particles having a high refractive index and polymer particles having a low refractive index can be mixed, or polymer particles having a refractive index difference in one particle can be used.
The addition amount of these coloring materials is preferably 0.01% to 90% by weight, more preferably 0.1% to 85% by weight, and particularly preferably 0.5% by weight with respect to the organic solvent B. To 80% by weight. When it is less than 0.01% by weight, the colorability of the dispersion solution is low, and when it is more than 90% by weight, the emulsion stability of the reaction phase may be lowered.

  The dispersed phase solution is composed of the resin and the organic solvent B as necessary, and further, a dispersed resin for dispersing the coloring material and, if necessary, an organic pigment or an inorganic pigment depending on the necessity and application. It is constituted by adding a dispersing agent such as The organic pigment or inorganic pigment is refined by a roll mill, a three-roll roll, a jet mill, a paint shaker, a homogenizer or the like, and then dispersed in a dispersed phase solution. The continuous phase is made into a continuous phase solution by mixing the organic solvent A, if necessary, a dispersed phase solution and a dispersing agent such as a dispersion resin for maintaining the dispersion stability of the finally obtained particles. The continuous phase solution and the dispersed phase solution are gently added, mixed, and stirred using a disper, homogenizer, homomixer, stirrer and stirrer, stirring blade, etc., and emulsified or suspended. It is preferable to maintain the dispersion at a temperature at which the evaporation of the organic solvent B is suppressed as much as possible until the oil droplets of the dispersed phase solution dispersed in the continuous phase by stirring have the target particle size. For example, when heat is generated by dispersion, the dispersion is cooled, and the temperature is preferably kept at 30 ° C. or lower, for example, 5 to 25 ° C. After the oil droplets of the dispersed phase solution reach the target particle size, the dispersion is depressurized or heated to remove the organic solvent B from the dispersion. When the organic solvent B is removed only by reducing the pressure, it is preferably performed in a vacuum of 5 Pa to 60 kPa, more preferably 5 Pa to 50 kPa. When removing the organic solvent B only by heating, the organic solvent B is heated at a temperature lower than the boiling point of the organic solvent A and allowing the organic solvent to evaporate. Moreover, when removing the organic solvent B by pressure reduction and heating, it is preferable to adjust the temperature in a vacuum of 5 Pa to 60 kPa, more preferably 5 Pa to 50 kPa, to a temperature at which the organic solvent A does not evaporate. There are no particular restrictions on the means for reducing the pressure, and usually the organic solvent B is removed in a vacuum degassing apparatus such as an evaporator. Moreover, there is no restriction | limiting in particular as a heating means, For example, a water bath, an oil bath, etc. can be used.

According to the present invention, nano-level to micro-level polymer particles and colored polymer composite particles are formed. For example, when using polymer particles for applications such as colored particles for electronic paper and colored materials for color filters, The average particle size is preferably 10 nm to 1000 μm, more preferably 10 nm to 200 μm, still more preferably 10 nm to 100 μm, and most preferably 20 nm to 10 μm.
Furthermore, in order to improve the characteristics of the electrophoretic display element and the electronic paper, the dispersion obtained by the above method can be adjusted with the amount of the organic solvent and the dispersant. As an organic solvent, in order to adjust the migration speed of particles, it is diluted with low carbon number, for example, hexane, octane, decane, dodecane, etc., or Isopar G, Isopar H or Isopar M (trade name: manufactured by ExxonMobil). Is possible. In addition, for example, sorbitan trioleate can be added to the dispersion as an interfacial conditioner. The addition amount of the interfacial modifier is 0.01 to 10% by weight, particularly 0.05 to 5% by weight, when the dispersion is 100% by weight.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by a following example.
[Example 1]
As a continuous phase, 2.5% by weight of dispersion resin Solsperse 17000 (manufactured by Nippon Lubrizol Co., Ltd., basic dispersant), aliphatic hydrocarbon solvent hexadecane (manufactured by Wako Pure Chemical Industries, Ltd., boiling point: about 210 ° C.) Was mixed and dissolved at 97.5% by weight (hereinafter referred to as a continuous phase solution). As a dispersed phase, GSM-301 (manufactured by Misawa Ceramics, styrene-maleic acid copolymer resin, weight average molecular weight: 8,000, Tg: 80 ° C.) 10% by weight, dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) ), Polyfunctional acrylate) 10% by weight, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (manufactured by Kayaku Akzo, thermal polymerization initiator) 0.1% by weight, Spisol as a dye Red 7345 (manufactured by Arimoto Chemical Industry Co., Ltd.) was mixed with 10 wt% and acetone (sp value = 9.4) at 69.9 wt% and dissolved (hereinafter referred to as a dispersed phase solution). To the 100 mL polycup, 20% by weight of the dispersed phase solution and 80% by weight of the continuous phase solution were added to make a total amount of 20 g. This mixture was emulsified and dispersed for 10 minutes using a homogenizer (ULTRA SONIC HOMOGENIZER UH-150: manufactured by SMT, Company). As a result of measuring the oil droplets after the initial dispersion with a particle size distribution meter (ZETASIZER 3000HSA: manufactured by MALVERN Instruments), an average particle size of about 200 nm was obtained. When performing the homogenizer, the temperature of the dispersion was kept at 20 ° C. or lower while cooling a 100 mL polycup with ice water in order to remove heat generated by the dispersion. In order to remove acetone present in the dispersed phase solution of the emulsified dispersion, deacetone treatment was performed at 40 ° C. under a vacuum of 50 kPa using an evaporator for 6 hours. The amount of acetone remaining 6 hours after the deacetone treatment was detected by gas chromatography, but it was the detection limit, and it was confirmed that acetone was almost completely removed. The average particle diameter of the colored polymer composite particles colored in red in the colored polymer composite particle dispersion obtained after deacetone was about 500 nm.

  Furthermore, as a result of measuring the zeta potential with a zeta potentiometer (ZETASIZER 3000HSA: manufactured by MALVERN Instruments), it was confirmed to be colored polymer composite particles having a negative charge.

  Furthermore, physical energy, so-called ultrasonic waves, was applied, and the level of particle breakage obtained was evaluated with the particle size distribution analyzer. The difference in particle size distribution was an error level. From this, it is considered that there is a high resistance to physical energy.

[Example 2]
Dissolved by mixing 2.5 wt% dispersion resin Solplus K210 (manufactured by Nippon Lubrizol Co., Ltd.) and 97.5 wt% aliphatic hydrocarbon solvent hexadecane (manufactured by Wako Pure Chemical Industries, Ltd.) as a continuous phase. (Hereinafter referred to as a continuous phase solution). As a dispersed phase, 10% by weight of GSM-301 (manufactured by Misawa Ceramics Co., Ltd.), 10% by weight of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., polyfunctional acrylate), 2,2′-azobis ( 4-methoxy-2,4-dimethylvaleronitrile) (manufactured by Kayaku Akzo, thermal polymerization initiator) 0.1% by weight, organic pigment Pigment Yellow 74 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 10% by weight, acetone Was mixed and dissolved at 69.9% by weight (hereinafter referred to as a dispersed phase solution). To the 100 mL polycup, 20% by weight of the dispersed phase solution and 80% by weight of the continuous phase solution were added to make a total amount of 20 g. This mixed liquid was treated in the same manner as in Example 1, and the resulting yellow colored colored polymer composite particles had an average particle diameter of 500 nm and were colored polymer composite particles having a wide distribution.

  Furthermore, as a result of measuring the zeta potential with a zeta electrometer (ZETASIZER 3000HSA: manufactured by MALVERN Instruments), it was found to be a colored polymer composite particle having a negative charge.

  Furthermore, physical energy, so-called ultrasonic waves, was applied, and the level of destruction of the obtained particles was evaluated with the particle size distribution meter. The difference in particle size distribution was an error level. From this, it is considered that there is a high resistance to physical energy.

[Comparative Example 1]
As continuous phase, dispersion resin Solsperse 17000 (manufactured by Nippon Lubrizol Co., Ltd.) was mixed and dissolved at 2.5% by weight and aliphatic hydrocarbon solvent octane (manufactured by Wako Pure Chemical Industries) at 97.5% by weight (hereinafter referred to as “the continuous phase”). , Indicated as continuous phase solution). As a dispersed phase, 10% by weight of GSM-301 (manufactured by Misawa Ceramics Co., Ltd.), 10% by weight of pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd., polyfunctional acrylate), 2,2′-azobis (4 -Methoxy-2,4-dimethylvaleronitrile) (manufactured by Kayaku Akzo, thermal polymerization initiator) 0.1% by weight, organic pigment Pigment Yellow 74 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 10% by weight, acetone The mixture was mixed and dissolved at 69.9% by weight (hereinafter referred to as a dispersed phase solution). To the 100 mL polycup, 20% by weight of the dispersed phase solution and 80% by weight of the continuous phase solution were added to make a total amount of 20 g. This mixture was emulsified and dispersed for 10 minutes using a homogenizer (ULTRA SONIC HOMOGENIZER UH-150: manufactured by SMT, Company). However, the stability of the dispersed phase and the continuous phase was so low that particles could not be obtained.

[Comparative Example 2]
As a continuous phase, dispersion resin SSoplus K210 (manufactured by Nippon Lubrizol Co., Ltd.) was mixed and dissolved at 2.5% by weight, and aliphatic hydrocarbon solvent decane (manufactured by Wako Pure Chemical Industries, Ltd.) at 97.5% by weight ( Hereinafter referred to as a continuous phase solution). As a dispersed phase, 10% by weight of GSM-301 (manufactured by Misawa Ceramics Co., Ltd.), 10% by weight of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., polyfunctional acrylate), 2,2′-azobis ( 4-methoxy-2,4-dimethylvaleronitrile) (manufactured by Kayaku Akzo, thermal polymerization initiator) 0.1% by weight, organic pigment Pigment Yellow 74 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 10% by weight, acetone Was mixed and dissolved at 69.9% by weight (hereinafter referred to as a dispersed phase solution). To the 100 mL polycup, 20% by weight of the dispersed phase solution and 80% by weight of the continuous phase solution were added to make a total amount of 20 g. This mixture was emulsified and dispersed for 10 minutes using a homogenizer (ULTRA SONIC HOMOGENIZER UH-150: manufactured by SMT, Company). However, the stability of the dispersed phase and the continuous phase was so low that particles could not be obtained.

Claims (12)

An aliphatic hydrocarbon solvent having 14 to 30 carbon atoms (hereinafter referred to as organic solvent A) and an organic solvent having a solubility parameter (hereinafter referred to as sp value) of 9.0 to 10.0 (cal · cm ⁻³ ) ^1/2 A non-aqueous emulsification dispersion method using an organic solvent B that is almost incompatible with A, and (meth) acryloyl in one molecule that can be dissolved in the organic solvent B but not in the organic solvent A A monomer having two or more groups (hereinafter referred to as a polyfunctional monomer) is dissolved, or a resin that is soluble in the organic solvent B but not dissolved in the organic solvent A is contained, and further, radicals are generated by light or heat. A polymerization initiator is dissolved to obtain a dispersed phase solution, and the dispersed phase solution is dispersed in the organic solvent A to obtain a dispersion composed of the dispersed phase of the dispersed phase solution and the continuous phase of the organic solvent A. Then, by light or heat, Cross-linking reaction Is allowed, the method of manufacturing vacuum or and removing the organic solvent B by heating the polymer particle dispersion in which the polymer particles are dispersed in an organic solvent A from the dispersion. The method for producing a polymer particle dispersion according to claim 1, wherein the organic solvent B is a polar solvent having a boiling point lower than that of the organic solvent A and a higher evaporation rate. Dispersed phase solution dissolves the polyfunctional monomer alone in the organic solvent B, or contains the resin at the same time, and can be dissolved or dispersed in the organic solvent B but not dissolved in the organic solvent A 3. The method for producing a polymer particle dispersion according to claim 1, wherein the polymer particle dispersion is a colored polymer composite particle dispersion dispersed in an organic solvent A. . The method for producing a polymer particle dispersion according to any one of claims 1 to 3, wherein the average particle diameter is 10 nm to 100 µm. The method for producing a polymer particle dispersion according to claim 3, wherein the coloring material is a solid selected from one or more of a dye, an inorganic pigment, and an organic pigment. The method for producing a polymer particle dispersion according to any one of claims 1 to 3, wherein the resin is a resin having a negatively dissociating polar group. The method for producing a polymer particle dispersion according to any one of claims 1 to 3, wherein the resin is a resin having a positively dissociating polar group. A polymer particle dispersion obtained by the method for producing a polymer particle dispersion according to claim 1. A liquid toner using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion according to claim 1. A display element using polymer particles obtained by the method for producing a polymer particle dispersion according to claim 1. Colored particles for electrophoretic display elements using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion according to any one of claims 1 to 7. Colored particles for electronic paper using the polymer particle dispersion obtained by the method for producing a polymer particle dispersion according to any one of claims 1 to 7.