JP2007291359A - Hollow polymer particle, colored hollow polymer particle and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow polymer particle and a colored hollow polymer particle of the nano-meter order having a high porosity and to provide a simple method under a low-environmental load for producing the hollow polymer particles with which the particles are produced by utilizing a pseudo-emulsion radical polymerization process wherein a dispersion stabilizer such as a surfactant need not be used. <P>SOLUTION: The hollow polymer particle is characterized in that the particle is composed of a shell wall comprising a copolymer obtained by polymerizing a monomer group (I) containing a radically polymerizable water-soluble monomer (A) and a radically polymerizable water-insoluble monomer (B) as a principal constituent component and the average value of the thickness of the shell wall is 5-80 nm. The method for producing the hollow polymer particle is characterized as carrying out radical polymerization of the monomer group (I) containing the radically polymerizable water-soluble monomer (A) and the radically polymerizable water-insoluble monomer (B) in an aqueous medium using a water-soluble polymerization initiator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to hollow polymer particles, and more particularly to a hollow polymer particle having a thin shell wall and a high porosity, a colored hollow polymer particle, and a simple production method thereof.

  Hollow polymer particles are widely used as microcapsules containing various functional substances inside the particles. In addition, since it has unique light scattering characteristics due to internal pores, in the field of coating and paint on paper, fiber, leather, etc., a light scattering agent for imparting performance such as gloss, opacity, whiteness, It is known to be useful as a light scattering aid. Furthermore, since the inside is hollow, a bulky and light weight and a heat insulating effect can be expected.

  Several methods have been proposed for producing such hollow polymer particles. For example, a central layer polymer composed of a copolymer of 20 to 60% by mass of a carboxy group-containing monomer and 80 to 40% by mass of a monomer copolymerizable therewith, and 1 to 12% by mass of a carboxy group-containing monomer. And an intermediate layer polymer composed of a copolymer of 99 to 88% by mass of a monomer copolymerizable therewith, and a surface layer polymer composed of a polymer of a monomer not containing a carboxy group, at least three layers Hollow polymer particles are obtained by adding an alkali to a latex containing polymer particles having a structure to bring the pH of the latex to 8 or more, and then adding an acid to bring the pH of the latex to 7. A method has been proposed (see, for example, Patent Document 1).

  Moreover, the manufacturing method of the hollow polymer particle using a dynamic swelling method is disclosed (for example, refer patent document 2). In this production method, first, in a hydrophilic organic solvent, for example, in a seed polymer particle such as polystyrene particle, a monomer such as divinylbenzene, a water-insoluble organic solvent such as toluene, and azobisisobutyronitrile. By absorbing the oil-soluble polymerization initiator, the seed polymer particles are swollen or dissolved. By this operation, the water-insoluble organic solvent dissolves the seed polymer particles, and droplets containing the seed polymer particles, the monomer, the water-insoluble organic solvent, and the oil-soluble polymerization initiator are obtained. When the temperature is raised in this state, due to the presence of the oil-soluble polymerization initiator, the monomers in the droplets are polymerized to form a first shell layer composed of a polymer film of the monomers, in which water is contained. There are seed polymer particles dissolved in an insoluble organic solvent. By drying the particles thus obtained, the water-insoluble organic solvent in the core portion is volatilized, and the seed polymer particles adhere to the inside of the shell layer made of the monomeric polymer coating. The hollow polymer particle which has is obtained.

  However, in the method proposed in Patent Document 1, in order to obtain hollow polymer particles, polymer particles having a structure of at least three layers are produced in advance, and thus the process is complicated. In addition, after the obtained particles are alkali-treated, it is necessary to perform acid treatment and post-treatment, and there is a problem that many steps and time are required. Furthermore, since hollow particles are produced using particles having a three-layer structure, it is difficult to increase the porosity of the resulting hollow polymerizable particles.

  Also in the method disclosed in Patent Document 2, in order to obtain hollow polymerizable particles, seed polymer particles are required as described above, and after dispersing these in a hydrophilic organic solvent, dynamic A plurality of steps of swelling of seed polymer particles and seed polymerization by the swelling method must be performed, and many steps and time are required. Further, the hollow polymerizable particles obtained by this method also have a second shell layer formed from a seed polymer on the inner wall, so that the porosity is low, and the size of the obtained particles is large on the order of micrometers. Therefore, nano-sized particles cannot be obtained.

  As described above, conventionally known methods for producing hollow polymerizable particles generally require a plurality of steps, and the production efficiency is poor, and the development of a simple method is an important issue to be solved. . In addition, improving the porosity of the hollow polymer particles to be produced is a necessary development requirement item in application development of the particles.

  Therefore, a method for obtaining hollow particles with a small number of steps has also been studied.For example, a solution obtained by dissolving a target component and a polymerization initiator in a monomer component into a uniform solution is added to water containing a dispersion stabilizer, A method of obtaining fine particles in which a target component is encapsulated in a hollow portion of a hollow fine particle composed of a shell and a hollow portion by carrying out suspension polymerization while heating is disclosed (for example, see Patent Document 3). In this method, if a specific organic solvent is used as the target component, solvent-encapsulated fine particles can be obtained, and by removing this solvent, single-layer hollow polymer fine particles having a high porosity can be obtained.

  However, in the method proposed in Patent Document 3, the polymerization itself can obtain hollow polymer particles without going through a plurality of steps, but the target component and the polymerization initiator are dissolved in the monomer component to obtain a uniform solution. Avoid the use of dispersion stabilizers to disperse the product in water, and special dispersion methods such as the use of dispersion methods using mechanical shearing force such as homogenizers and membrane emulsification methods. I couldn't. In addition, the size of the droplets in the dispersion obtained from the above dispersion method is not monodispersed, but a mixture of droplets of various different particle sizes, and the particle size distribution of the finally obtained hollow polymer particles is There was a problem of polydispersion. Therefore, in order to obtain hollow particles having a uniform particle size, improvement of the pretreatment process is a prerequisite, such as using a special emulsification method using porous glass (SPG).

  In any of the hollow polymer particle manufacturing methods described above, the hollow structure inducing method is based on the spontaneous organization process of molecules using the polymerization activity due to the polymerizable monomer molecular structure and the change in physical properties of the growing polymer accompanying the polymerization of the monomer. It is completely irrelevant, and hollow particles are obtained by increasing the number of processes based on processive techniques. Production of hollow polymer particles by radical polymerization is still often dependent on this method, and development of a production process with energy saving and low environmental load is a challenging issue.

  In addition, radical polymerization reaction at the water / oil interface in a so-called W / O type inverse emulsion medium in which water droplets are dispersed in the oil phase by utilizing the hydrophilic-hydrophobic change with temperature of poly (N-isopropylacrylamide). There is also disclosed a method for obtaining hollow fine particles by performing (see, for example, Non-Patent Document 1). In this method, first, an aqueous solution in which N-isopropylacrylamide and tetraethylenepentamine are dissolved is emulsified in toluene (oil layer) in which divinylbenzene as a crosslinking agent for radical polymerization is dissolved to form a W / O type inverse emulsion. Let Thereafter, benzoyl peroxide is added to the oil phase, causing an oxidation-reduction reaction between the peroxide and tetraethylenepentamine dissolved in the water droplets at the water / oil interface, and the resulting radicals are converted to N in the water droplets. Causes a polymerization reaction of isopropylacrylamide. Since poly (N-isopropylacrylamide) growing in water droplets is a thermosensitive polymer, it becomes hydrophobic when the temperature of the reaction system is lower than the lower critical eutectic temperature (LCST, 3234 ° C.) of poly (N-isopropylacrylamide). Change and move to the water / oil interface rather than in the water droplets. At that interface, a copolymerization reaction proceeds with the cross-linking agent divinylbenzene dissolved in a large amount in the oil phase, and a crosslinked polymer insoluble in water and oil is formed at the water / oil interface. As a result, hollow particles using water droplets as a mold can be obtained.

  In the method of Non-Patent Document 1, although the polymerization process itself can obtain hollow particles without going through a plurality of steps, it is necessary to use an emulsifier in order to form a W / O type inverse emulsion. It was necessary to carry out complicated operations in all steps, such as the selection of the type, amount used, and emulsification method. In this method, since the radical polymerization reaction proceeds at the water / oil interface of the W / O inverse emulsion, even if the initial water droplet size is uniform before polymerization, the water droplet size in the entire polymerization process is Therefore, it is impossible to control the particle size or the film thickness of the hollow particles, and as a result, the particles are relatively large particles having a diameter of 1 to 3 μm and the shell thickness is 100 nm. Only particles with thick shells were obtained. In addition, in this method, radical polymerization at the water / oil interface is completely impossible without a heat-responsive water-soluble polymer having a lower critical eutectic temperature (LCST), and development to a wide range of monomers is impossible. Further, since it is a W / O type inverse emulsion, a large amount of organic solvent such as toluene must be discharged, and its environmental load is very large.

JP-A-6-2448012 JP-A-8-020604 JP 2003-096108 A Q. Sun, et al., “Journal of American Chemical Society”, Vol. 127, 2005, p. 8274-8275

  In view of the above circumstances, an object of the present invention, that is, an object is to provide nanometer-order hollow polymer particles and colored hollow polymer particles having a high porosity, and to disperse these particles with a surfactant or the like. It is an object of the present invention to provide a simple and low environmental load hollow polymer particle production method that utilizes a pseudo-emulsion radical polymerization process that does not require the use of an agent.

  As a result of intensive studies to solve the above problems, the inventors of the present invention contain a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B). It is found that by polymerizing the monomer group to be polymerized in an aqueous medium, hollow polymer particles having a hydrophilic surface and a high porosity are generated while spontaneously forming a polymer aggregate during the progress of the polymerization reaction. The invention has been completed.

  That is, the present invention is obtained by polymerizing the monomer group (I) containing the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B). The present invention provides a hollow polymer particle comprising a shell wall containing a copolymer as a main component, and having an average thickness of the shell wall of 5 nm to 80 nm, and a method for producing the hollow polymer particle.

  Further, the present invention is obtained by polymerizing a monomer group (I) containing a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B). The present invention also provides a colored hollow polymer particle comprising a shell wall containing a copolymer (X) and a colorable compound (Y) as main constituents, and a method for producing the same.

  According to the present invention, hollow polymer particles having a high porosity can be obtained. The hollow polymer particles are produced by using a water-soluble polymerization initiator in a water-based polymerization medium in a water-soluble monomer having a radical polymerizable property and a water-insoluble monomer having a radical polymerizable property. It can be obtained by a simple and reproducible method of pseudoemulsion radical polymerization. The obtained hollow polymer particles also have monodispersibility, and the shell wall has a thin thickness of 5 nm to 80 nm and the surface is hydrophilic, and therefore exists stably in an aqueous medium. The hollow polymer particles can have various functional molecules incorporated into the hollow during or after production, and can be particles having various functions based on the incorporated functional molecules. . In particular, colored hollow polymer particles can also be obtained by physically bonding (adsorbing) or chemically bonding a coloring compound.

  Accordingly, the hollow polymer particles of the present invention utilize the unique light scattering characteristics due to the internal pores in the fields of aqueous coatings and paints, and perform performance such as gloss, opacity, whiteness, etc. on paper, fiber, leather, etc. It can be applied as a light scattering property improver for imparting water and a white pigment. Moreover, it can be applied to cosmetics utilizing light diffusivity, water absorption and oil absorption by a hollow structure, and can also be used as an ink jet receiving layer. In addition, since it has a hollow structure, heat conduction and sound conduction can be suppressed, so that it can be applied as a heat insulating material or a sound insulation material, and can be used as a lightening agent because the weight in the same volume can be reduced. Furthermore, it can also be used as a chemical substance holding agent that contains various chemical substances inside, and a chemical substance sustained release agent that releases components contained inside by some stimulus such as heat, pressure, pH change, It can also be used as a DDS material.

  The method for producing hollow polymer particles of the present invention does not require complicated steps over multiple stages, uses a conventional radical polymerization method, and supplies the hollow polymer particles at a low cost for the various uses described above. In addition, since it is easy to design a structure according to various uses, it is excellent in industrial utility.

The present invention is described in detail below.
The hollow polymer particles of the present invention use a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B) as essential raw materials, and these monomer groups ( It has a polymer layer obtained by copolymerizing I) as a shell, and its thickness is as thin as 5 to 80 nm. It is possible to control the thickness of the shell made of the polymer layer in the range of 5 nm to 80 nm by adjusting the kind and the use ratio of the water-soluble monomer (A) and the water-insoluble monomer (B). is there. From an industrial application point of view, hollow polymer particles having a shell thickness of less than 5 nm or greater than 80 nm are undesirable. This is because when the shell thickness is less than 5 nm, the shape stability as the hollow polymer particle is deteriorated, and when it exceeds 80 nm, the carrier function when the substance is loaded on the hollow portion of the hollow polymer particle is lowered. .

  Even in ordinary radical polymerization systems, polymerization activity derived from characteristics of monomers used as raw materials, changes in polymer segment physical properties when growing from monomer to polymer, type of polymerization initiator, polymerization medium, etc. If it can be used skillfully, it is considered possible to induce the domain of the polymer aggregate by driving the self-organizing force of the molecule simultaneously with the polymerization reaction.

  In the present invention, a water-soluble polymerization initiator is combined with the monomer group (I) containing the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B). Spontaneous formation of hollow polymer particles was completed by radical polymerization in a completely aqueous medium. That is, when two types of monomers having different polymerization activities and affinity to an aqueous medium are copolymerized, random copolymerization is not necessarily performed, and the unit of monomer 1 is concentrated in the copolymer. This is based on the phenomenon that a thick segment is formed by the unit of the simple segment and the monomer 2 and functions as an amphiphilic polymer.

  The monomer group (I) containing the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B) used in the present invention is copolymerized in an aqueous medium. In doing so, the water-soluble monomer (A) has a very low molar concentration compared to the water-insoluble monomer (B). When the polymerization is performed using a water-soluble initiator, the water-soluble monomer (A) is preferentially polymerized, and a hydrophilic segment derived from the monomer (A) is formed. However, when the hydrophilic segment of the terminal radical grows to a certain size, a depletion interaction is strongly induced between the water-insoluble monomer droplets due to factors such as an increase in the degree of polymerization, A phenomenon occurs in which the growing hydrophilic segment is concentrated on the surface of the droplet. In other words, the periphery of the growth end of the hydrophilic segment is filled with the water-insoluble monomer (B). Therefore, the addition reaction of the water-insoluble monomer (B) starts at the radical growth terminal of the hydrophilic segment, and the polymerization of the water-insoluble monomer (B) proceeds rapidly, resulting in two contradictions. A copolymer having segments of the nature is produced. The copolymer having the hydrophobic segment and the hydrophilic segment thus produced acts as a so-called polymer surfactant, and during the polymerization reaction, the copolymer spontaneously sandwiches the hydrophobic segment. Aggregates into bilayer polymer aggregate particles (polymer vesicles). As a result, a large amount of the remaining water-insoluble monomer (B) is polymerized while being taken into the membrane of the aggregated particles, and finally the inner and outer surfaces similar to the polymer vesicle structure are hydrophilic, Hollow polymer particles having a thin wall thickness are provided. In the present invention, the above polymerization process is defined as pseudoemulsion polymerization.

  The average particle diameter of the hollow polymer particles obtained in this way can be 50 nm to 5 μm depending on the purpose, but the aforementioned aggregates are stable due to the production method by the pseudo emulsion polymerization method. In particular, hollow polymer particles of 50 nm to 1 μm can be easily produced. In addition, the particle size distribution is determined based on the type of water-soluble monomer (A), water-insoluble monomer (B) and water-soluble initiator used as a raw material, and the aggregate formed spontaneously depending on the blending ratio. Since it is based on monodispersion, a coefficient of variation of 0.1 or less can be easily produced.

  The shell wall of the hollow polymer particles of the present invention can be obtained with different thicknesses depending on the particle size. For example, hollow polymer particles having an average particle size of 50 nm or more and less than 300 nm can be prepared with a shell wall thickness of 5 nm to 30 nm, and hollow polymer particles having an average particle size of 300 nm or more and less than 1 μm The wall thickness can be 5 nm to 80 nm. The thickness of the shell wall can be suitably selected and produced within the above range according to the purpose. However, in order to maintain a high porosity and a sufficient strength of the shell wall, a hollow polymer having a thickness of 50 nm or more and less than 300 nm. The particles preferably have a shell wall with a thickness of 5 nm to 15 nm, and the hollow polymer particles having an average particle diameter of 300 nm or more and less than 1 μm are more preferably a shell wall with a thickness of 10 nm to 40 nm. As for the thickness of the shell wall, a uniform one can be obtained by the spontaneous organization accompanying the polymerization of the monomer, similarly to the particle diameter. That is, the thickness of the whole shell of one particle is uniform, and the thickness of the shell of all the particles obtained under the same conditions is also uniform. In the present invention, the average value of the results of measuring the shell thickness of the hollow polymer particles observed by SEM at 30 locations was defined as the shell wall thickness.

  The radically polymerizable water-soluble monomer (A) used in the present invention is not particularly limited, but is preferably one that dissolves 1.0% by mass or more with respect to distilled water. And those having an amide group, an amino group, an oxyalkylene chain, a cyano group, an acid anhydride group, and the like can be used. Further, for example, those having a carboxy group, a hydroxy group, a sulfonic acid group, a phosphoric acid group and the like, and those having an alkali metal salt or ammonium salt thereof can be used. Specifically, examples of the water-soluble monomer having an amide group include acrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, Nn-propylacrylamide, N -N-propylmethacrylamide, N-cyclopropylacrylamide, N-cyclopropylmethacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N-dimethylaminopropylacrylamide, N-methyl-N-ethyl N-substituted (meth) acrylamide such as acrylamide, N-methyl-N-isopropylacrylamide, N-methyl-Nn-propylacrylamide, N-disubstituted (meth) acrylamide, N-hydroxyethylacrylamide Acryloyl morpholine, N- vinylpyrrolidone, diacetone acrylamide, N, N'-methylene bis-acrylamide. Examples of the water-soluble monomer having an amino group include allylamine, N, N-dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and the like. Examples of the water-soluble monomer having a carboxy group include acrylic acid, methacrylic acid, and maleic acid. Examples of the water-soluble monomer having a hydroxy group include 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate. , 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, and the like. Examples of the water-soluble monomer having a sulfonic acid group include styrene sulfonic acid, sodium styrene sulfonate, lithium styrene sulfonate, ammonium styrene sulfonate, ethyl styrene sulfonate, cyclohexyl styrene ester, 2-acrylamide-2- Examples thereof include methyl propane sulfonic acid. Further, a quaternized monomer obtained by quaternizing a monomer synthesized by reacting vinyl pyridine or glycidyl methacrylate with an organic amine may be used.

  Among these water-soluble monomers (A), those having an amide group, an amino group, a carboxy group or a salt thereof, a sulfonic acid group or a salt thereof in the structure are industrially available, water-soluble, radical This is preferable from the viewpoint of excellent ease of polymerization.

  Furthermore, N-substituted acrylamide and N, N-disubstituted acrylamide are considered to have a surface-active action from the viewpoint of having a hydrophobic group and a hydrophilic group in one molecule, and the homopolymers thereof are: It has a unique property that the degree of water solubility varies depending on the degree of polymerization and the temperature of the aqueous medium. Due to these properties, the reaction mechanism described above can be easily achieved, and the hollow polymer particles of the present invention can be more easily produced.

  In addition, a homopolymer of N-substituted acrylamide or N, N-disubstituted acrylamide has a lower critical solution temperature (LCST) in an aqueous solution and causes a coil-globule transition in the vicinity of this temperature, The polymer chain is hydrated and hydrophilic, but the specific property that the polymer chain shrinks and becomes hydrophobic at high temperatures also affects the surface structure of the resulting hollow polymer particles. The particle diameter of the particles has a temperature-responsive layer that is large on the low temperature side and small on the high temperature side with the LCST as a boundary in a state of being dispersed in the aqueous medium.

  The thickness of the temperature-responsive layer in the aqueous medium varies depending on the molar ratio of the radical polymerizable water-insoluble monomer (B) and the radical polymerizable water-soluble monomer (A) used. Also, it varies depending on the particle diameter of the obtained hollow polymer particles. For example, with hollow polymer particles having an average particle diameter of 50 nm or more and less than 300 nm, a temperature-responsive layer having a thickness of 5 nm to 100 nm can be produced, and a hollow having an average particle diameter of 300 nm or more and less than 1 μm. Polymer particles having a temperature-responsive layer of 5 nm to 200 nm can be produced.

  As the radical polymerizable water-insoluble monomer (B) used in the present invention, various monomers can be used as long as they have a group copolymerizable with the water-soluble monomer (A). Although it is possible to use, it is preferable that the solubility in distilled water is 0.5% by mass or less, particularly excellent in reactivity with the water-soluble monomer (A) and easy to obtain industrially. From a certain point, acrylate or methacrylate is preferable.

  Examples of the acrylate include butyl acrylate, lauryl acrylate, cyclohexyl acrylate, phenyl acrylate, isobornyl acrylate, glycidyl acrylate, tert-butyl-α-trifluoromethyl acrylate, 1-adamantyl-α-trifluoromethyl. Examples thereof include acrylate, (3-methyl-3-oxetanyl) methyl acrylate, acryloylpropyltrimethoxysilane, acryloylpropyltriethoxysilane, methyl acrylate, and ethyl acrylate.

  Examples of the methacrylate include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, stearyl methacrylate, glycidyl methacrylate, allyl methacrylate, 2 2,2-trifluoroethyl methacrylate, (3-methyl-3-oxetanyl) methyl methacrylate, methacryloylpropyltrimethoxysilane, methacryloylpropyltriethoxysilane, and the like. These radically polymerizable water-insoluble monomers (B) can be used alone or in admixture of two or more. Hereinafter, (meth) acrylate used in the text is used as a general term for acrylate alone, methacrylate alone and mixtures thereof unless otherwise specified.

  Among the radical polymerizable water-insoluble monomers (B), those having a cyclic ether structure such as glycidyl (meth) acrylate and oxetane (meth) acrylate are the above-mentioned radical polymerizable water-soluble monomers (A )), Or after the formation of the copolymer, a cross-linking reaction can be carried out within or between the molecules of the copolymer, and the resulting hollow polymer can be obtained by the cross-linking reaction. Since it is thought that it contributes to increasing the strength of the copolymer forming the shell part of the particle and improving the stability of the hollow polymer particle, it can be used particularly suitably.

As the radical polymerizable water-insoluble monomer (B), a bifunctional di (meth) acrylate such as polyethylene di (meth) acrylate such as ethylene di (meth) acrylate, diethylene (meth) acrylate, triethylene di (meth) acrylate, etc. ) Acrylates, propylene di (meth) acrylate, dipropylene di (meth) acrylate, tripropylene di (meth) acrylate, etc., polypropylene di (meth) acrylates, glycerol di (meth) acrylate, etc. alone or in combination Can be used in combination. When these di (meth) acrylates are used, they are preferably used in combination with the monofunctional (meth) acrylate for the purpose of preventing aggregation of the resulting hollow particles, and particularly radically polymerizable water-insoluble monomers. The use ratio of (meth) acrylate in (B) is preferably 0.7 or more in terms of molar ratio.

  As the radical polymerizable water-insoluble monomer (B), other than (meth) acrylate, for example, a styrene compound, vinyl ester, vinyl ether, bisvinyl compound or the like alone or in combination of two or more. Can be used. At this time, it is preferable to use together with (meth) acrylate from the viewpoint of easily obtaining the hollow polymer particles of the present invention, and in particular, the (meth) acrylate in the radical polymerizable water-insoluble monomer (B). The use ratio is preferably 0.5 or more in terms of molar ratio.

  The styrenic compound is a compound having a styryl group. For example, styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-, m-, p-chlorostyrene, p-ethylstyrene, p- tert-butoxystyrene, m-tert-butoxystyrene, p-acetoxystyrene, p- (1-ethoxyethoxy) styrene, p-methoxystyrene, styryltrimethoxysilane, styryltriethoxysilane, vinylnaphthalene, vinylbiphenyl, vinylanthracene And vinylpyrene.

  Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl monochloroacetate, vinyl pivalate, and vinyl butyrate.

  Examples of the vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, allyl vinyl ether, cyclohexane dimethanol monovinyl ether, Examples include 1,4-butanediol divinyl ether, nonanediol divinyl ether, cyclohexanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylpropane trivinyl ether, pentaerythritol tetravinyl ether, and phenyl vinyl ether.

  Examples of the bisvinyl compound include divinylbenzene and the like, and since a cross-linked structure is generated in the shell of the hollow polymer particles, it is preferable because stable hollow particles can be produced.

  The ratio of use of the radical polymerizable water-insoluble monomer (B) and the radical polymerizable water-soluble monomer (A) includes the average particle diameter and the shell wall thickness of the target hollow polymer particles. From the point that hollow polymer particles that can exist stably in an aqueous medium are obtained and the hollow structure is stable, the radically polymerizable water-insoluble monomer (B) and the radical are selected. The molar ratio (B) / (A) to the polymerizable water-soluble monomer (A) is preferably from 3.5 to 12, and particularly preferably from 3.5 to 10. In the production method of the present invention to be described later, the monomer group (I) is not added all at once, but the polymerization proceeds to some extent and after the formation of the hollow polymer particles, the radical polymerizable water-insoluble monomer. When the body (B) is added to control the average particle diameter and the shell wall thickness of the hollow polymer particles, stable hollow polymer particles can be obtained even when the ratio exceeds 12.

  The colored hollow polymer particle of the present invention is a combination of the above-mentioned hollow polymer particle and a coloring compound, and includes a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer. It comprises a shell wall comprising a copolymer (X) obtained by polymerizing a monomer group (I) containing (B) and a coloring compound (Y) as main components. .

  As the radically polymerizable water-soluble monomer (A) and the radically polymerizable water-insoluble monomer (B) that can be used here, any of the above-mentioned ones can be used in the same manner. The same applies to the body.

  As the coloring compound (Y), in addition to a compound having light absorption in the visible light region (400 nm to 800 nm), the chemical structure is changed by absorbing ultraviolet light such as photochromic molecules, and the like. A compound showing absorption or a compound showing light emission in the visible light region can also be used.

  In the colored hollow polymer particles of the present invention, the monomer group (I) containing the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B) is polymerized. The copolymer (X) obtained in this way and the coloring compound (Y) may be physically bonded or chemically bonded. Furthermore, the coloring compound (Y) may be one type or plural. In this case, a physical bond and a chemical bond may exist at the same time.

  The colored hollow polymer particles in which the copolymer (X) and the coloring compound (Y) are physically bonded are, for example, the presence of the coloring compound (Y) in the method for producing the colored hollow polymer particles described later. By carrying out radical polymerization under the above, the coloring compound (Y) is encapsulated inside hollow polymer particles having a shell whose main component is the copolymer (X), and the aqueous medium is removed by drying or the like In this case, a substance adsorbed on the inner surface of the shell wall or a substance obtained by adsorbing the coloring compound (Y) dissolved in the aqueous medium on the surface of the hollow polymer particles in the aqueous medium removing step.

  In addition, the colored hollow polymer particles in which the copolymer (X) and the coloring compound (Y) are physically bonded include a radical polymerizable water-insoluble monomer in the method for producing the colored hollow polymer particles described below. By dissolving the coloring compound (Y) having low water solubility in the body (B) and performing radical polymerization, the inside of the shell of the hollow polymer particles containing the copolymer (X) as a main constituent is colored. Also includes those in which compound (Y) is dispersed.

  Further, the colored hollow polymer particles in which the copolymer (X) and the colorable compound (Y) are chemically bonded include, for example, a reactive group present in the copolymer (X), And a coloring compound (Y) having a group capable of chemically bonding, and by reacting them, the shell part constituting the hollow polymer particle has a structure derived from the coloring compound (Y). Is. In this case, since the coloring compound (Y) is present in the shell of the hollow polymer particle by a chemical bond, a stable colored hollow polymer particle is obtained.

  As the coloring compound (Y) used in the present invention, water-soluble dyes, oil-soluble dyes, and the like can be used. The water-soluble dye is not particularly limited as long as it is a dye that is soluble in an aqueous medium used in the production of the hollow polymer particles of the present invention described later, and various natural and organic synthetic dyes can be used. For example, azo dye, anthraquinone dye, indigo dye, sulfur dye, diphenylmethane dye, triphenylmethane dye, acridine dye, xanthene dye, azine dye, oxazine dye, thiazine dye, azomethine dye, nitro dye, nitroso dye, thiazole dye, methine Dyes, polymethine dyes, cyanine dyes, porphyrins, phthalocyanine dyes, and the like can be used. Moreover, the compound which water-solubilized by sulfonated and sulfonated salt, such as naphthalene sulfonic acid, sodium naphthalene sulfonate, sodium pyrene sulfonate, etc. can also be used suitably. These water-soluble dyes can be used alone or in combination of two or more.

  The oil-soluble dye is not particularly limited as long as it is an oil-soluble dye that dissolves in the radical polymerizable water-insoluble monomer (B), and is a monoazo dye, disazo dye, anthraquinone dye, or perylene dye. Further, condensed polycyclic pigments such as quinophthalone and anthrapyridone can be used. Furthermore, condensed polycyclic aromatic compounds such as naphthalene, anthracene, tetracene, pentacene, phenanthrene, chrysene, triphenylene, pyrene and their derivative molecules, oligophenylenes such as biphenyl, terphenyl and their derivative molecules, azobenzene, spiropyran, spirooxazine, Photochromic dyes that are fulgide, diarylethene, and derivatives thereof can also be suitably used. These oil-soluble dyes can be used alone or in combination of two or more.

  The colored hollow polymer particles of the present invention preferably have a shell wall thickness of 5 nm to 80 nm. Within this thickness range, similarly to the hollow polymer particles described above, the colored hollow polymer particles are stable in water and have a wide range of applications. Moreover, it can be used suitably also when mixing and using the above-mentioned hollow polymer particle.

The hollow polymer particles and colored hollow polymer particles of the present invention are a monomer group (I) containing a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B). ) Can be easily obtained by emulsion polymerization in an aqueous medium.
Hereafter, the manufacturing method of this invention is explained in full detail.

  The production method of the present invention is to produce hollow polymer particles in one pot, that is, in the same reaction vessel without requiring an isolation operation. The radical-polymerizable water-soluble monomer (A) and radical It is characterized in that pseudo-emulsion radical polymerization of the polymerizable water-insoluble monomer (B) is carried out in an aqueous medium using a water-soluble polymerization initiator.

  As an aqueous medium used for the pseudo-emulsion polymerization, in addition to using water alone, lower alcohols such as methanol, ethanol, and isopropanol, polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, and triethylene glycol are used. Mention may be made of ketones such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran alone or a mixed solvent in which a plurality of them are mixed.

  The mixing ratio when using the mixed solvent is such that the water-soluble polymerization initiator and the radical-polymerizable water-soluble monomer (A) described later are soluble and the radical-polymerizable water-insoluble monomer. The solubility of the body (B) may be in the range of 0.5% by mass or less, and can be appropriately selected according to the purpose, but in order to keep the polymerization initiation efficiency by the water-soluble polymerization initiator high, the proportion of water Is preferably 50% by mass or more, particularly preferably 80% by mass or more.

  The water-soluble polymerization initiator is not particularly limited, and various types can be used, but it is preferable to use a persulfate or an amino group-containing azo compound. For example, potassium persulfate (KPS) ), Ammonium persulfate (APS), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2, 2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2′-azobis [N- (2-carboxyethyl) 2-methylpropionamide], 2, 2′-azobis (1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] pro Dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2 , 2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis (2-methylbutanamidooxime) dihydrochloride tetra Hydrate, etc. are mentioned.

  The use ratio of these water-soluble polymerization initiators is about 0.1 parts by mass with respect to a total of 100 parts by mass of the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B). The content may be appropriately selected in the range of 1 to 5 parts by mass, but it is more preferable to select in the range of 0.5 to 3 parts by mass for the purpose of increasing the efficiency of the polymerization reaction and suppressing the aggregation of the hollow polymer particles.

  In the production of the hollow polymer particles of the present invention, the desired hollow polymer particles can be produced without using any dispersion stabilizer such as a surfactant, but various dispersion stabilizers can be used together as necessary. good. Examples of the dispersion stabilizer include an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, and an organic suspension protective agent. Among them, the hollow polymer particles are efficiently used. Therefore, it is preferable to use an anionic surfactant or a cationic surfactant.

  Examples of the anionic surfactant include rosin salts such as potassium rosinate and sodium rosinate, sodium oleate, potassium laurate, sodium laurate, sodium laurate, sodium stearate, potassium stearate, and the like. Examples thereof include salts, sulfate esters of aliphatic alcohols such as sodium lauryl sulfate, and alkylallyl sulfonic acids such as sodium dodecylbenzene sulfonate.

  Examples of nonionic surfactants include polyethylene glycol alkyl esters, alkyl ethers, alkylphenyl ethers, and the like.

  Examples of the cationic surfactant include alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, alkyl dimethyl benzyl ammonium salts, and amine salt surfactants.

  Examples of amphoteric surfactants include alkylamino fatty acid salts, alkylbetaines, and alkylamine oxides.

  These dispersion stabilizers can be used alone or in combination of two or more as required. In using a dispersion stabilizer, an ionic surfactant or nonionic surfactant having the same charge as the surface electrification imparted to the particles by a water-soluble polymerization initiator in order to prevent aggregation of the resulting hollow polymer particles Is preferably used.

  The amount of the dispersion stabilizer used may be appropriately selected as necessary. However, when the concentration at the initial stage of the reaction is too high, normal emulsion polymerization proceeds and the particles are less likely to exhibit a hollow structure. Therefore, it is preferable to reduce the amount used in the initial stage and add it later as the particles are formed.

  In the production method of the present invention, the polymerization reaction temperature may be appropriately set in the range of 35 to 90 ° C. in accordance with the polymerization start temperature of the water-soluble polymerization initiator to be used. It is preferable to set in the range of 40 to 85 ° C, more preferably in the range of 60 to 80 ° C, from the viewpoint of improving the performance and preventing evaporation of the aqueous medium and suppressing instability of the reaction system. preferable.

  In the production method of the present invention, if the concentration of the monomer during polymerization is too low, the synthesis efficiency of the hollow polymer particles is poor, and if it is too high, aggregation is likely to occur. It is preferable to select appropriately within the range according to the purpose. From the viewpoint of efficiently obtaining more stable hollow polymer particles, the concentration is preferably selected from the range of 1 to 10% by mass.

  In the production method of the present invention, the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B) are added in advance in an aqueous medium, A conventional one-pot manufacturing method of radical polymerization in which polymerization is performed using a water-soluble polymerization initiator can be employed.

  In addition, polymerization is performed using a water-soluble polymerization initiator in a state where a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B) are added in advance in an aqueous medium. It can also be synthesized by a one-pot manufacturing method in which a radically polymerizable water-insoluble monomer (B) is further added while the polymerization reaction is in progress. When the post-addition method is used, the thickness of the hollow shell wall can be increased.

  Further, in the method for producing these hollow polymer particles, a radically polymerizable water-soluble monomer is used by using a water-soluble polymerization initiator in a state in which a coloring compound (Y) having high water solubility is dissolved in an aqueous medium. The colored hollow polymer particles of the present invention can be obtained by emulsion polymerization of the monomer group (I) containing the body (A) and the radically polymerizable water-insoluble monomer (B). .

  Further, the coloring compound (Y) having low water solubility is dissolved in the radical polymerizable water-insoluble monomer (B), and the radical polymerizable water-soluble monomer is dissolved by using a water-soluble polymerization initiator. The colored hollow polymer particles of the present invention can also be obtained by polymerizing the monomer group (I) containing the monomer (A) and the radically polymerizable water-insoluble monomer (B). .

  In these methods, the amount of the coloring compound (Y) used may be set in any range depending on the purpose within a range that does not inhibit the progress of polymerization, but is a radically polymerizable water-soluble monomer. The molar ratio of the monomer group (I) containing (A) and the radically polymerizable water-insoluble monomer (B) is 3 mol% or less, preferably 1 mol% or less.

  Further, the colored hollow polymer particles can be obtained also by adding the coloring compound (Y) after the production of the hollow polymer particles, and the amount of the coloring compound (Y) used at this time is obtained hollow The polymer particles can be used at any ratio depending on the purpose within a range where aggregation of the polymer particles does not occur. In particular, when an ionic coloring compound is used, it has a surface charge of the hollow polymer particles, that is, a charge opposite to the charge derived from the functional group contained in the water-soluble monomer (A) used as a raw material. It is preferable to use one.

  Moreover, as a method of chemically bonding the copolymer (X) constituting the shell of the colored hollow polymer particles and the colorable compound (Y), for example, a method of polymerizing using a radically polymerizable colorable compound in combination, A method in which a radically polymerizable functional group is introduced into a coloring compound having a reactive functional group and the resulting compound (Y ′) is used in combination for polymerization. After obtaining hollow polymer particles, the hollow polymer particles are formed. And a method of chemically reacting a coloring compound with a reactive group in the copolymer.

  Among these, from the viewpoint of versatility and bonding certainty, a method of introducing a radical polymerizable functional group into a coloring compound having a reactive functional group to obtain a radical polymerizable coloring compound (Y ′) Is preferred. Specifically, coloring compounds having an amino group, for example, 7-amino-4-methylcoumarin, 7-amino-4-trifluoromethylcoumarin, aminofluorescein, aminonaphthalene, aminoanthracene, aminopyrene, aminobiphenyl and the like , A method of reacting glycidyl (meth) acrylate, (meth) acrylic acid chloride and the like, a coloring compound having a hydroxyl group, 7-hydroxy-4-methylcoumarin, 6-hydroxy-4-methylcoumarin, fluorescein, hydroxymethyl Examples include a method of reacting biphenyl, 2- (hydroxymethylanthracene) and the like with (meth) acrylic acid chloride and the like.

  Emulsion polymerization using the radically polymerizable coloring compound (Y ′) obtained above, the water-soluble monomer (A), and the water-insoluble monomer (B) as described above. By this, a structure derived from a coloring compound can be introduced into the shell wall constituting the hollow polymer particle, and the colored hollow polymer particle can be obtained. The water-soluble monomer (A) and the water-insoluble monomer (B) used at this time may be the same as or different from those reacted with the coloring compound. Moreover, when the obtained radically polymerizable coloring compound (Y ′) is water-soluble, the entire amount as the water-soluble monomer (A) used for obtaining the hollow polymer particles is radically polymerizable coloring compound (Y ′). ). Further, when the radically polymerizable coloring compound (Y ′) is water-insoluble, the whole amount of the water-insoluble monomer (B) used for obtaining the hollow polymer particles is radically polymerizable coloring compound (Y). ') May be replaced.

  The method of using the hollow polymer particles and colored hollow polymer particles obtained in the present invention is not particularly limited. For example, in the field of water-based coatings and paints, gloss, It can be used as a light scattering improver, white pigment, hiding agent, etc. for imparting performance such as transparency, whiteness, etc. Also, marking effect due to coloring components in colored hollow polymer particles, coloring / decoloring It can be used for rewritable materials, anti-counterfeit coatings, and special-purpose papers that utilize effects and light-emitting properties. Furthermore, it can be applied to cosmetics utilizing light diffusibility, water absorption, and oil absorption by a hollow structure, and can also be used as an ink jet receiving layer. Furthermore, since the heat conduction and sound conduction can be suppressed due to the hollow structure, it can be applied as a heat insulating material or a sound insulation material, and can be used as a lightening agent because the weight in the same volume can be reduced. Furthermore, it can be used as a chemical substance holding agent containing various chemical substances inside, and can also be used as a chemical substance sustained release agent and a DDS material. Further, the hollow polymer particles containing a coloring component can be used as a labeled high-functional drug carrier or affinity beads. For use in such applications, the fact that the hollow polymer particles of the present invention are monodispersed and that the shell wall is thin is effective for efficiently and uniformly expressing various performances required for the application. Therefore, its usefulness is high.

  Next, in order to describe the present invention in more detail, examples and comparative examples will be given, but it is needless to say that the present invention is not limited by these descriptions.

  The particle size of the particles dispersed in water was measured by a dynamic light scattering method using a particle size measuring device FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.

  To confirm the shape and hollowness of the fine particles, SEM observation using a 3D real surface view microscope VE-9800 manufactured by Keyence Corporation is performed, and for measuring the shell thickness of the hollow polymer particles, a field emission scanning type manufactured by Hitachi, Ltd. is used. The SEM observation image by electron microscope S-800 was used.

(Synthesis of hollow polymer particles)
Example 1
<Synthesis of Hollow Polymer Particles Consisting of Copolymer poly (NIPAM-co-GMA) of N-Isopropylacrylamide (NIPAM) and Glycidyl Methacrylate (GMA)>
Add 8.52 g of glycidyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as GMA) to 200 ml of an aqueous solution in which 1.4 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd., hereinafter referred to as NIPAM) is dissolved, and then add nitrogen. Heat to 70 ° C. with stirring under atmosphere. To the mixture (GMA / NIPAM = 4.8 mol / mol), 20 ml of an aqueous solution in which 0.1 g of potassium persulfate (KPS, manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble polymerization initiator was dissolved was added. A particle dispersion was obtained by stirring at the same temperature for 1 hour. This dispersion was washed and purified by centrifugation. After purification, the particles were identified by dynamic light scattering, SEM, and ¹ HNMR. When the particle size of the particles was measured by a dynamic light scattering method, it showed a monodispersed particle size distribution (FIG. 1). The average particle size at 25 ° C. was 407 nm and the coefficient of variation was 0.03. The average particle size at 50 ° C. was 325 nm, and it was confirmed to have a temperature-responsive layer of about 40 nm. When the shape of the fine particles in a dry state was observed with an SEM, they were monodispersed spherical particles (FIG. 2). When the fine particles were crushed and the morphology was observed, it was confirmed that the center of the particles was a hollow polymer particle having a hollow (FIG. 3). The thickness of the shell wall of this particle was 10 nm (FIG. 4). When the hollow polymer particles were dispersed in heavy water and ¹ H-NMR was measured at 25 ° C., the spectrum shown in FIG. 5 was obtained. These signals are attributed to CH ₃ and CH of the isopropyl group by the hydrophilic poly (N-isopropylacrylamide) [δ = 1.093 (6H), 3.823 (1H)], respectively. The presence of the hydrophilic polymer segment was confirmed.

Examples 2 to 26
<Synthesis of hollow polymer particles composed of copolymers of various water-soluble monomers and water-insoluble monomers>
In Example 1, except that the water-soluble monomer (A), the water-insoluble monomer (B), the water-soluble polymerization initiator, and the amount of the aqueous solution used are changed to the values shown in Table 1, respectively. In the same manner, hollow polymer particles were obtained. Table 2 summarizes the property values of the obtained particles. In Example 6, sodium lauryl sulfate was used as the surfactant, and a predetermined amount was added to the NIPAM aqueous solution and stirred uniformly.

Footnotes in Table 1:
MBAM: N, N′-methylenebisacrylamide DMAA: N, N-dimethylacrylamide ACMO: acryloylmorpholine AA: acrylic acid MAP-TMACl: 3- (methacryloylamino) propyltrimethylammonium chloride ME-SO3Na: 2- (methacryloyl) Roxy) Ethylenesulfonic acid sodium salt St-SO3Na: Sodium styrenesulfonate MMA: Methyl methacrylate OX-MA: (3-Methyl-3-oxetanyl) methacrylate F-Et-MA: 2,2,2-trifluoroethyl methacrylate APTEtOSi : Acryloylpropyltriethoxysilane AIBA: 2,2′-azobis (2-amidinopropane) dihydrochloride

Example 27
<Synthesis of poly (NIPAM-co-GMA) hollow polymer particles by two-stage addition of water-insoluble monomer>
To 200 ml of an aqueous solution in which 0.7 g of NIPAM was dissolved, 4.5 g of GMA was added and heated to 70 ° C. with stirring in a nitrogen atmosphere (GMA / NIPAM = 5.1 mol / mol). To the mixture, 20 ml of an aqueous solution in which 0.05 g of KPS was dissolved was added as a water-soluble polymerization initiator. After stirring for 1 hour at the same temperature, 2.2 g of GMA was further added (total GMA / NIPAM = 7.6 mol / mol), followed by stirring for 1 hour at the same temperature to obtain a particle dispersion. After the dispersion was washed by centrifugation, the particle size of the particles was measured by a dynamic light scattering method. As a result, it showed a monodispersed particle size distribution, the average particle size at 25 ° C. was 380 nm, and the coefficient of variation was 0. 03. Observation of the shape of the particles revealed monodispersed true spherical particles. When the particles were crushed and the morphology was observed, it was confirmed that the center of the particles was a hollow polymer particle (FIG. 12).

Examples 28-34
<Synthesis of various hollow polymer particles by two-stage addition of water-insoluble monomer>
In Example 27, except that the water-soluble monomer (A), the water-insoluble monomer (B), the water-soluble polymerization initiator, and the amount of the aqueous solution used are changed to the values shown in Table 3, respectively. In the same manner, hollow polymer particles were obtained. Table 4 summarizes the property values of the obtained particles.

(Synthesis of colored hollow polymer particles)
Example 35
<Synthesis of colored hollow polymer particles containing rhodamine B>
1.4 g of NIPAM and 8.84 g of GMA were added to 200 ml of an aqueous solution containing 5 mg of rhodamine B (manufactured by Wako Pure Chemical Industries, Ltd.), and heated to 70 ° C. with stirring in a nitrogen atmosphere. In this mixture (GMA / NIPAM = 5.0 mol / mol, dye / polymerizable monomer = 1.3 × 10 ⁻⁴ mol / mol), 20 ml of an aqueous solution in which 0.1 g of KPS was dissolved was added. A particle dispersion was obtained by stirring at the same temperature for 1 hour. After the dispersion was washed by centrifugal separation, the particle size of the particles was measured by a dynamic light scattering method. The average particle size at 25 ° C. was 670 nm. The average particle diameter at 50 ° C. was 600 nm and had a temperature-responsive layer of about 35 nm. When the fine particles were crushed and the morphology was observed, it was confirmed that the center of the particles was hollow polymer particles (FIG. 13). The thickness of the shell wall of this particle was 20 nm. The particles were red, and emitted green-red fluorescence when irradiated with visible light near 530 nm under an optical microscope (FIG. 14).

Example 36
<Synthesis of colored hollow polymer particles containing pyrene>
A mixed solution of 13.1 mg of pyrene (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.89 g of GMA was added to 20 ml of an aqueous solution containing 0.14 g of NIPAM, and heated to 70 ° C. with stirring under a nitrogen atmosphere. In this mixture (GMA / NIPAM = 5.0 mol / mol, dye / polymerizable monomer = 8.6 × 10 ⁻³ mol / mol), 10 mg of polymerization initiator AIBA was added, and the same temperature was maintained for 1 hour. By stirring, a dispersion of particles having an average particle diameter of 380 nm and a coefficient of variation of 0.06 was obtained. After the dispersion was washed by a centrifugal separation operation, the fine particles were crushed and the morphology was observed. As a result, it was confirmed that the center of the particle was a hollow polymer particle having a hollow (FIG. 15). The thickness of the shell wall of this particle was 10 nm. The particles emitted blue pyrene fluorescence when irradiated with ultraviolet light (FIG. 16).

Example 37
<Synthesis of colored hollow polymer particles containing spironaphthoxazine>
To 20 ml of an aqueous solution in which 0.14 g of NIPAM is dissolved, a mixture of 11.6 mg of spironaphthoxazine (SP-99, manufactured by Nippon Photosensitizer) and 0.87 g of GMA is added, and the mixture is stirred up to 70 ° C. under a nitrogen atmosphere. Heated. To this mixture (GMA / NIPAM = 4.8 mol / mol, dye / polymerizable monomer = 4.7 × 10 ⁻³ mol / mol), 11 mg of AIBA was added and stirred at the same temperature for 1.5 hours. As a result, a dispersion of particles having an average particle size of 280 nm and a coefficient of variation of 0.05 was obtained. When the fine particles were crushed and the morphology was observed, it was confirmed that the center of the particles was a hollow polymer particle having a hollow, and the thickness of the shell wall of the particle was 10 nm. When the obtained white hollow polymer particles were irradiated with ultraviolet light from a mercury lamp, the color changed to blue. When the ultraviolet light was blocked, the fine particles returned to white, and it was confirmed that the hollow polymer particles exhibited photochromic properties.

Example 38
<Synthesis of colored hollow polymer particles containing aminopyrene residues>
A mixed solution containing 0.013 g of GMA derivative combined with aminopyrene and 0.87 g of GMA was added to 20 ml of an aqueous solution in which 0.14 g of NIPAM was dissolved, and the mixture was heated to 70 ° C. with stirring in a nitrogen atmosphere. In this mixture (GMA / NIPAM = 5.0 mol / mol, radical-polymerizable coloring compound / polymerizable monomer = 6.0 × 10 ⁻³ mol / mol), 11 mg of KPS was added at the same temperature. Was stirred for 1 hour to obtain a dispersion of particles having an average particle size of 250 nm and a coefficient of variation of 0.03. When this dispersion was washed by centrifugation, a white fine particle dispersion was obtained. When this dispersion was irradiated with ultraviolet light, blue fluorescence was emitted. When the fine particles were crushed and the form was observed, it was confirmed that the center of the particles was hollow polymer particles having a hollow, and the thickness of the shell wall was 10 nm.

3 is a particle size distribution of the hollow polymer particles obtained in Example 1 by dynamic light scattering measurement. 2 is an SEM observation image showing the form of hollow polymer particles obtained in Example 1. FIG. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 1. It is a FE-SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 1. 3 is a ¹ H-NMR spectrum of the hollow polymer particles obtained in Example 1 in heavy water. 3 is an SEM observation image showing the form of hollow polymer particles obtained in Example 2. It is a SEM observation image showing the hollow form which crushed and observed the hollow polymer particle obtained in Example 2. FIG. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 3. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 4. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 5. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 6. It is a SEM observation image showing the hollow form observed by crushing the hollow polymer particle obtained in Example 27. It is a SEM observation image showing the hollow form observed by crushing the coloring monodisperse hollow polymer particles obtained in Example 35. 2 is a fluorescence emission spectrum of colored hollow polymer particles obtained in Example 35. FIG. It is a SEM observation image showing the hollow form observed by crushing the colored hollow polymer particles obtained in Example 36. 2 is a fluorescence emission spectrum of colored hollow polymer particles obtained in Example 36. FIG.

Claims (18)

The main component is a copolymer obtained by polymerizing a monomer group (I) containing a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B). Hollow polymer particles comprising a shell wall as a component, and an average thickness of the shell wall of 5 nm to 80 nm. The hollow polymer particles according to claim 1, wherein the average particle size is 50 nm to 1 µm and the particle size distribution is monodisperse. The hollow polymer particles according to claim 2, wherein the average particle system is 50 nm or more and less than 300 nm, and the shell wall thickness is 5 nm to 30 nm. The hollow polymer particles according to claim 2, wherein the average particle system is 300 nm or more and 1 µm or less, and the thickness of the shell wall is 5 nm to 80 nm. The molar ratio (B) / (A) of the radical polymerizable water-insoluble monomer (B) to the radical polymerizable water-soluble monomer (A) in the monomer group (I) is 3. The hollow polymer particle according to claim 1, which is 5 to 12. The radical polymerizable water-soluble monomer (A) has at least one functional group selected from the group consisting of an amide group, an amino group, a carboxy group and a salt thereof, and a sulfonic acid group and a salt thereof in the structure. The hollow polymer particle according to claim 1, which is a polymer. The hollow polymer particle according to claim 1, wherein the radical polymerizable water-soluble monomer (A) is at least one selected from the group consisting of N-substituted acrylamide and N, N-disubstituted acrylamide. The hollow polymer particle according to claim 1, wherein the radical polymerizable water-insoluble monomer (B) is at least one selected from the group consisting of acrylate and methacrylate. The hollow polymer particle according to any one of claims 1 to 8, wherein the monomer group (I) is radically polymerized in an aqueous medium. A monomer group (I) containing a radically polymerizable water-soluble monomer (A) and a radically polymerizable water-insoluble monomer (B) in an aqueous medium using a water-soluble polymerization initiator. A method for producing hollow polymer particles, wherein radical polymerization is performed with The method for producing hollow polymer particles according to claim 10, wherein the water-soluble polymerization initiator is a persulfate or an amino group-containing azo compound. The method for producing hollow polymer particles according to claim 10, wherein the concentration of the monomer group (I) in the aqueous medium at the time of radical polymerization is 1 to 10% by mass. The molar ratio (B) / (A) of the radically polymerizable water-insoluble monomer (B) and the radically polymerizable water-soluble monomer (A) is from 3.5 to 12. A method for producing hollow polymer particles. Copolymer (X) obtained by polymerizing monomer group (I) containing radically polymerizable water-soluble monomer (A) and radically polymerizable water-insoluble monomer (B) And a colored hollow polymer particle comprising a shell wall having a colorable compound (Y) as main components. The colored hollow polymer particles according to claim 14, wherein the bond between the copolymer (X) and the coloring compound (Y) is at least one selected from the group consisting of a physical bond and a chemical bond. The colored hollow polymer particle according to claim 14 or 15, wherein a thickness of a shell wall of the colored hollow polymer particle is 5 nm to 80 nm. A monomer group (I) containing a radically polymerizable water-soluble monomer (A) and a radically polymerizable water-insoluble monomer (B) is colored using a water-soluble polymerization initiator. A method for producing colored hollow polymer particles, wherein radical polymerization is performed in the presence of a compound (Y). At least one selected from the group consisting of a radically polymerizable water-soluble monomer (A) and a radically polymerizable water-insoluble monomer (B) and a coloring compound (Y) are reacted in advance to produce radicals. After obtaining the polymerizable coloring compound (Y ′), the radical polymerizable water-soluble monomer (A) and the radical polymerizable water-insoluble monomer (B) are used with a water-soluble polymerization initiator. A method for producing colored hollow polymer particles, characterized by radical polymerization.