Polymer particulate, method for producing the same, composition, optical member, light source unit, display, illumination device, and ink

Abstract

To provide polymer particulates that have high light transmittance and low birefringence, making them suitable for optical applications, while also demonstrating high particulate sphericity as well as superior uniformity and isotropy.SOLUTION: Polymer particulates are primarily composed of a resin that has a light transmittance of 85% or more within a wavelength range of 400 nm or more and 800 nm or less, and an intrinsic birefringence of -30×10-4 or more +30×10-4 or less, where the D50 particle size is 0.1 μm or more and 100 μm or less and the sphericity is 80 or more and 100 or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to polymer microparticles and a method for producing the same, a composition containing the polymer microparticles, and optical members, light source units, displays, lighting devices, and inks produced by using the polymer microparticles. [Background technology]

[0002] Polymer microparticles are fine particles made of polymers, and their diameters are generally from tens of nanometers to hundreds of micrometers. Unlike polymer molded products such as films, fibers, injection molded products, and extrusion molded products, polymer microparticles have a large specific surface area and a fine particle shape, which allows them to be used to modify and improve various materials. Major applications include cosmetic modifiers, toner additives, optical applications such as light diffusion and light absorption, rheology modifiers for paints, medical diagnostic testing agents, additives for molded products such as automotive materials and building materials, and powder raw materials for 3D printers.

[0003] Conventional methods for producing polymer microparticles can be roughly classified into build-up processes such as radical polymerization and top-down processes such as mechanical pulverization and dissolution / precipitation.

[0004] A representative build-up process is radical polymerization of a vinyl polymer, such as emulsion polymerization (see, for example, Patent Document 1).

[0005] Typical methods that are easily used as top-down processes are mechanical pulverization and solution precipitation. Mechanical pulverization is a method in which resin pellets are frozen using liquid nitrogen or the like and then mechanically pulverized. Solution precipitation is a method in which resin is dissolved in a solvent and the solubility is reduced by cooling, solvent removal, or the like to obtain fine particles (see, for example, Patent Document 2).

[0006] Furthermore, a particle formed by dissolving a light emitting material together with a resin having excellent optical performance, extracting particles by a spray drying method, and incorporating the light emitting material into a resin matrix has been reported (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 7-133328 [Patent Document 2] JP 2005-054153 A [Patent Document 3] WO2020 / 050144 publication Summary of the Invention [Problem to be solved by the invention]

[0008] However, the resins considered for the build-up process described in Patent Document 1 are limited to some vinyl polymers made from acrylic, styrene, etc., and there is a problem that there is a limit to obtaining polymer microparticles with a desired resin suitable for optical applications. In addition, since the polymer is produced by polymerizing an emulsified monomer, it is inevitable that the emulsifier, polymerization initiator, and altered products thereof remain in the polymer microparticles after polymerization, and there is a problem of changes in optical properties, such as coloring caused by trace impurities, during long-term use in optical applications.

[0009] On the other hand, the top-down process has the advantage that polymer microparticles can be obtained from resins with excellent optical performance because resins with desired properties are processed into fine particle shapes. In addition, since the purified high-purity resin can be directly granulated, it has the advantage of preventing trace impurities from remaining in the polymer microparticles. However, among these methods, the mechanical pulverization method requires freezing the resin, which increases energy costs, and the pulverized material obtained generally has an irregular shape. In addition, the dissolution precipitation method described in Patent Document 2 also has the problem of generally having an irregular shape, as well as the problem of the particles becoming porous and having a large specific surface area.

[0010] Furthermore, in recent years, the illuminance required for light sources in optical applications has increased, and the deterioration of components containing luminescent materials and coloring materials has become an issue. The above Patent Document 3 indeed discloses a technology for suppressing the propagation of highly active species by microparticulating polymers and suppressing accelerated deterioration of the entire component, but the existing technology has not yet been able to fully solve this issue with the rapid increase in illuminance of light sources. Specifically, the design technology for the composition and shape of polymer microparticles was insufficient. For example, the technology disclosed in the above Patent Document 3 certainly makes it possible to prepare polymer microparticles containing luminescent materials and coloring materials, but is insufficient in terms of optimizing the resin that constitutes the particles, and there is also a problem that optical loss and accelerated deterioration occur due to the particle shape becoming indefinite.

[0011] Therefore, an object of the present invention is to provide polymer fine particles which are suitable for optical applications and further have high particle sphericity, uniformity and isotropy. [Means for solving the problem]

[0012] In order to solve the above problems and achieve the object, the present invention has the following configuration. [1] The light transmittance is 85% or more in the wavelength range of 400 nm to 800 nm, and the inherent birefringence is -30 × 10 -4 Above +30×10 -41. Polymer microparticles mainly composed of a resin having a D50 particle size of 0.1 μm or more and 100 μm or less, and a sphericity of 80 or more and 100 or less. [2] The polymer microparticles according to [1], having a linseed oil absorption of 1 mL / 100 g or more and 200 mL / 100 g or less. [3] The polymer microparticles according to [1] or [2], wherein the D90 particle size / D10 particle size is 1.0 or more and 5.0 or less. [4] The specific gravity of the resin is 1.15 g / cm 3 The polymer microparticles according to any one of [1] to [3] below: [5] The polymer microparticles according to any one of [1] to [4], wherein the resin has a glass transition temperature of 100° C. or higher. [6] The polymer particles according to any one of [1] to [5], further comprising a light-emitting material or a coloring material. [7] The polymer microparticles according to [6], wherein the absorption spectrum of the light-emitting material or coloring material has at least one maximum peak in the wavelength range of 400 nm or more and 800 nm or less. [8] A method for producing polymer microparticles, comprising sequentially carrying out the following steps (a) and (b): (a) The light transmittance is 85% or more in the wavelength range of 400 nm to 800 nm, and the intrinsic birefringence is -30 × 10 -4 Above +30×10 -4 A process for forming an emulsion containing two phases: an organic phase containing a resin and an organic solvent, and an aqueous phase containing a water-soluble polymer, water and / or alcohol. (b) A step of heating and / or reducing the pressure of the emulsion while stirring to volatilize and remove a part or all of the organic solvent contained in the emulsion, thereby precipitating polymer fine particles. [9] The method for producing polymer microparticles described in [8], wherein the water-soluble polymer is one or more selected from the group consisting of polyvinyl alcohol, poly(vinyl alcohol-ethylene) copolymers, polyethylene glycol, cellulose derivatives, and polyvinylpyrrolidones.

[10] The method for producing polymer microparticles according to [8] or [9], wherein the organic phase further contains a light-emitting material or a coloring material.

[11] The method for producing polymer microparticles according to

[10] , wherein the absorption spectrum of the light-emitting material or coloring material has at least one maximum peak in the wavelength range of 400 nm or more and 800 nm or less.

[12] A composition comprising a binder resin and the polymer fine particles according to any one of [1] to [7].

[13] A light source unit comprising a light source and the polymer microparticles according to [6] or [7].

[14] A display comprising the light source unit according to

[13] .

[15]

[13] A lighting device comprising the light source unit.

[16] An ink comprising the polymer microparticles according to [6] or [7]. Effect of the Invention

[0013] The polymer particles according to the present invention are suitable for optical applications, and optical materials such as light source units and inks having extremely low optical loss can be obtained. [Brief description of the drawings]

[0014] [Figure 1] Scanning electron microscope photograph of the polymer microparticles obtained in Example 1 [Diagram 2] Scanning electron microscope photograph of polymer microparticles obtained in Comparative Example 2 [Diagram 3] Scanning electron microscope photograph of the polymer microparticles obtained in Example 3 [Figure 4] Scanning electron microscope photograph of polymer microparticles obtained in Comparative Example 3 [Diagram 5] FIG. 1 is a schematic cross-sectional view showing an example of an optical member according to an embodiment of the present invention. [Figure 6] FIG. 1 is a schematic cross-sectional view showing an example of an optical member according to an embodiment of the present invention. [Figure 7] FIG. 1 is a schematic cross-sectional view showing an example of an optical member according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be modified and implemented in various ways depending on the purpose and application.

[0016] In the present invention, "equal to or greater than" means equal to or greater than the indicated numerical value. "equal to or less than" means equal to or less than the indicated numerical value. "Less than" means less than the indicated numerical value.

[0017] (fine particles) The D50 particle size of the polymer microparticles according to the embodiment of the present invention is in the range of 0.1 to 100 μm. If the D50 particle size exceeds 100 μm, the particle size will be greater than the layer thickness of a film or the like used in optical materials, causing roughness and poor appearance. If the D50 particle size is less than 0.1 μm, the surface area of ​​the polymer microparticles will be large, which is undesirable as it will cause viscosity increase when used in a slurry or ink.

[0018] The upper limit of the D50 particle size of the polymer microparticles is preferably 70 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, particularly preferably 20 μm or less, extremely preferably 10 μm or less, and most preferably 5 μm or less, and the lower limit is preferably 0.2 μm or more, more preferably 0.5 μm or more, even more preferably 1.0 μm or more, even more preferably 1.5 μm or more, and particularly preferably 2.0 μm or more.

[0019] The D50 particle size of the polymer microparticles is the particle size (D50 particle size) at which the cumulative frequency from the small particle size side of the particle size distribution measured by a laser diffraction particle size distribution analyzer is 50%.

[0020] The particle size distribution of the polymer microparticles is expressed by the ratio of the D90 particle size to the D10 particle size (hereinafter referred to as D90 / D10), and is preferably 1.0 to 5.0. The narrower the particle size distribution of the polymer microparticles, the greater the optical uniformity, since the difference in light scattering caused by the difference in particle size is eliminated. Therefore, the upper limit of D90 / D10 is more preferably 4.0 or less, and even more preferably 3.0 or less. The lower limit is more preferably 1.5 or more, and even more preferably 2.0 or more, in terms of excellent packing ability in a powder state.

[0021] The D90 / D10 of the polymer microparticles is the particle size (D90) at which the cumulative frequency from the small particle size side of the particle size distribution measured by the above-mentioned laser diffraction particle size distribution meter is 90%, divided by the particle size (D10) at which the cumulative frequency from the small particle size side is 10%.

[0022] The sphericity, which indicates the sphericity of the polymer microparticles according to the embodiment of the present invention, is from 80 to 100. If the sphericity is less than 80, the isotropy of light passing through the polymer microparticles is impaired. The sphericity is preferably from 85 to 100, more preferably from 90 to 100, even more preferably from 93 to 100, and particularly preferably from 95 to 100.

[0023] The sphericity of the polymer microparticles is determined by observing 30 particles randomly from a scanning electron microscope photograph and determining the sphericity from their minor and major axes according to the following formula.

[0024]

number

[0025] In this formula, S is sphericity, a is major axis, b is minor axis, and n is the number of measurements (30).

[0026] The smoothness of the surface of the polymer microparticles according to the embodiment of the present invention can be expressed by the amount of linseed oil absorbed (linseed oil absorption). That is, the smoother the surface, the less pores there are in the microparticles, and the lower the linseed oil absorption.

[0027] The linseed oil absorption of the polymer microparticles is preferably 1 mL / 100 g or more and 200 mL / 100 g or less. The smaller the linseed oil absorption of the polymer microparticles, the smoother the particle surface and the more solid the interior, reducing the optical loss due to undesired light scattering on the particle surface and multiple reflection inside the particle, and suppressing the accelerated deterioration of the luminescent material and coloring material due to multiple excitation. Furthermore, thickening can be suppressed when used in a slurry or ink. The upper limit of the linseed oil absorption is more preferably 150 mL / 100 g or less, more preferably 120 mL / 100 g or less, even more preferably 100 mL / 100 g or less, and particularly preferably 70 mL / 100 g or less. The lower limit is not particularly limited, but is more preferably 10 mL / 100 g or more, more preferably 20 mL / 100 g or more, and particularly preferably 30 mL / 100 g or more.

[0028] The linseed oil absorption of the polymer microparticles is measured in accordance with the Japanese Industrial Standards (JIS) K 5101 (2004) "Pigment Test Method - Refined Linseed Oil Method."

[0029] The surface smoothness and internal solidity of the polymer microparticles according to the embodiment of the present invention can be expressed by the BET specific surface area determined by gas adsorption. If the surface of the polymer microparticles is smooth and the interior is solid, optical loss due to light scattering on the surface and inside of the polymer microparticles can be reduced, which is preferable. Furthermore, the surface area is reduced, which improves fluidity and makes handling easier, which is also preferable. Here, it means that the smoother the surface, the smaller the BET specific surface area. Specifically, when the BET specific surface area of ​​the polymer microparticles is 10 m 2 / g or less, and more preferably 5m 2 / g or less, and more preferably 3m 2 / g or less, and particularly preferably 1m2 The lower limit is theoretically 0.05 m / g when the particle diameter is 100 μm. 2 / g.

[0030] The BET specific surface area of ​​the polymer fine particles is measured in accordance with the Japanese Industrial Standards (JIS) JIS R 1626 (1996) "Method of measuring specific surface area by gas adsorption BET method."

[0031] The solidity of the polymer microparticles according to the embodiment of the present invention can also be evaluated by the following formula, which indicates the ratio of the theoretical surface area calculated from the BET specific surface area and the D50 particle size. The closer the value of the following formula is to 1, the more the particles are solid and have a smooth surface, since adsorption occurs only on the outermost surface of the particles. The value of the following formula is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and most preferably 2 or less. The lower limit is theoretically 1.

[0032]

number

[0033] In this formula, R is the surface area ratio, D is the D50 particle size, α is the density of the polymer microparticles, and A is the BET specific surface area.

[0034] (Resin in fine particles) The resin that is the main component of the polymer microparticles according to the embodiment of the present invention has a light transmittance of 85% or more in the wavelength range of 400 nm or more and 800 nm or less. The higher the light transmittance, the more transparent the resin is, and the smaller the optical loss can be when used in a light source unit or the like. In addition, when the polymer microparticles contain a light-emitting material or a coloring material, the color development can be improved. The light transmittance is preferably 87% or more, more preferably 90% or more, even more preferably 91% or more, and particularly preferably 92% or more.

[0035] The light transmittance of a resin in the wavelength range of 400 nm or more and 800 nm or less can be measured by preparing a resin sample piece with a film thickness of 1 μm or more and 100 μm or less and using a commercially available measuring device (for example, a violet-visible spectrophotometer (product name U-3010) manufactured by Hitachi, Ltd.).

[0036] In addition, the resin has an inherent birefringence of -30×10 -4 Above +30×10 -4 The smaller the absolute value of the intrinsic birefringence, the more the light diffusion can be prevented. In addition, when the polymer fine particles contain a light-emitting material or a coloring material, the color development can be improved. The lower limit of the intrinsic birefringence is -25×10 -4 It is preferable that the value is equal to or higher than -20×10 -4 More preferably, -15×10 -4 That's all. The upper limit is +25×10 -4 It is preferable that the value is equal to or less than 20×10. -4 Below, more preferably +15×10 -4 The following is the result.

[0037] The intrinsic birefringence of a resin can be calculated by calculating the dielectric polarization difference in each bond unit of the structural units using a molecular orbital method such as the AM1 method or PM3 method, and then calculating the intrinsic birefringence value as the volume average using the Lorentz-Lorentz equation below.

[0038]

number

[0039] In this formula, Δn0 is the intrinsic birefringence, ΔP is the difference between the dielectric polarizability in the direction of the molecular chain axis and the dielectric polarizability in the direction perpendicular to the molecular chain axis, n is the refractive index, d is density, N is Avogadro's number, and M is molecular weight.

[0040] The specific gravity of the resin is set to 1.20 g / cm3 in order to make the material lighter. 3 It is preferable that the density is 1.15 g / cm or less. 3More preferably, it is 1.12 g / cm or less. 3 It is particularly preferred that:

[0041] The glass transition temperature (Tg) of the resin is preferably 100°C or higher, more preferably 110°C or higher, and particularly preferably 120°C or higher, from the viewpoint of suppressing thermal diffusion and molecular motion of the luminescent material contained therein. The upper limit of the Tg of the resin is not particularly limited, but is preferably 180°C or lower. The glass transition temperature of the resin can be measured by a commercially available measuring device (for example, a differential scanning calorimeter (trade name DSCQ20) manufactured by TA Instruments, Inc.) under the condition of a heating rate of 20°C / min. The form of the sample is not particularly limited as long as it is placed in a measurement container, but it is preferable to measure it in the form of powder, finely cut pellets, film, or in a state in which the resin solution is cast and then thoroughly dried to remove the solvent.

[0042] In the polymer microparticles according to the embodiment of the present invention, a material having excellent transparency, heat resistance, etc. is preferably used as the resin constituting the particles. Examples of the types of resin include known materials such as photocurable resist materials having reactive vinyl groups such as acrylic acid, methacrylic acid, polyvinyl cinnamate, and ring rubber, epoxy resin, silicone resin (including organopolysiloxane cured products (crosslinked products) such as silicone rubber and silicone gel), urea resin, fluorine resin, polycarbonate resin, acrylic resin, urethane resin, melamine resin, polyvinyl resin, polyamide resin, phenol resin, polyvinyl alcohol resin, cellulose resin, aliphatic ester resin, aromatic ester resin, aliphatic polyolefin resin, and aromatic polyolefin resin. Mixtures or copolymers of these resins may also be used. By appropriately designing these resins, resins useful for the polymer microparticles according to the embodiment of the present invention can be obtained.

[0043] Among these resins, from the viewpoint of transparency and dispersibility of light-emitting materials or coloring materials, it is preferable to use any one of acrylic resins, copolymer resins containing acrylic acid ester or methacrylic acid ester moieties, polyester resins, cycloolefin resins, epoxy resins, and silicone resins. More preferable are acrylic resins, copolymer resins containing acrylic acid ester or methacrylic acid ester moieties, and polyester resins, and particularly preferable are acrylic resins, copolymer resins containing acrylic acid ester or methacrylic acid ester moieties. Also, from the viewpoint of heat resistance, it is preferable to use thermosetting resins and photocurable resins.

[0044] The polymer microparticles according to the embodiment of the present invention are preferably mainly composed of a resin having at least one ring structure selected from the group consisting of an aliphatic hydrocarbon ring, an aliphatic heterocycle, and a ring containing SP3 carbon in the molecular structure. When the resin has a ring structure in the molecular structure, the molecular motion of the resin is suppressed, the change in the dispersion state of the light-emitting material or the coloring material is suppressed, and the proximity of these materials to each other can be suppressed. Furthermore, by having the ring structure be at least one ring structure selected from the group consisting of an aliphatic hydrocarbon ring, an aliphatic heterocycle, and a ring containing SP3 carbon, the π-conjugated structure in the resin is reduced, and the generation of active species due to light absorption is reduced. As a result, the deterioration of the light-emitting material or the coloring material can be suppressed, and the deterioration of the durability of the polymer microparticles can be prevented. Here, the SP3 carbon refers to a carbon atom bonded to four atoms in an SP3 hybrid orbital.

[0045] The number of atoms constituting the aliphatic hydrocarbon ring, the aliphatic heterocycle, and the ring containing SP3 carbon is not particularly limited, but is usually in the range of 3-30, preferably 4-20, and more preferably 5-15.

[0046] Specific examples of the ring structure containing aliphatic hydrocarbon ring, aliphatic heterocycle and SP3 carbon include, for example, cyclobutane, cyclopentane, cyclohexane, norbornene, adamantane, pyrrolidine, piperidine, ethylene oxide, oxetane, furan, tetrahydropyran, morpholine, dioxane, indane, fluorene, cyclic ester, cyclic amide, and derivatives thereof.Among them, cyclohexane, norbornene, adamantane, ethylene oxide, oxetane, fluorene, cyclic ester, cyclic amide, and derivatives thereof are preferred, cyclohexane, norbornene, adamantane, fluorene, cyclic ester, and derivatives thereof are more preferred, cyclohexane, norbornene, fluorene, cyclic ester, and derivatives thereof are even more preferred, and cyclohexane, norbornene, and derivatives thereof are particularly preferred.

[0047] The polymer microparticles according to the embodiment of the present invention preferably contain at least one of the following resins as the main component: a resin having at least one ring structure selected from the group consisting of an aliphatic hydrocarbon ring, an aliphatic heterocycle, and a ring containing SP3 carbon in the polymer main chain, and a resin having at least one ring structure selected from the group consisting of an aliphatic hydrocarbon ring, an aliphatic heterocycle, and a ring containing SP3 carbon directly bonded to the polymer main chain. When the ring structure is included in the polymer main chain or is directly bonded to the main chain, the molecular motion of the resin can be suppressed more efficiently than when the ring structure is introduced into the polymer side chain, and changes in the dispersion state of the light-emitting material or coloring material can be suppressed.

[0048] In order to disperse the light-emitting material or coloring material well in the resin, it is preferable that the resin has both a partial structure having high compatibility with the light-emitting material or coloring material and a partial structure having low compatibility with the light-emitting material or coloring material. A more preferable form of the resin is a copolymer randomly containing a partial structure having high compatibility with the light-emitting material or coloring material and a partial structure having low compatibility with the light-emitting material or coloring material.

[0049] Examples of partial structures having high compatibility with light-emitting materials or coloring materials include, but are not limited to, sites derived from acrylic acid, methacrylic acid, acrylic acid esters, and methacrylic acid esters, and sites linked by ester bonds or amide bonds. On the other hand, examples of partial structures having low compatibility with light-emitting materials or coloring materials include, but are not limited to, sites derived from vinyl compounds consisting of only carbon atoms and vinyl compounds having aliphatic hydrocarbon rings. Therefore, it is preferable that the resin has at least one of a site derived from acrylic acid, methacrylic acid, acrylic acid esters, or methacrylic acid esters, and a site linked by ester bonds or amide bonds, and at least one of a site derived from a vinyl compound consisting of only carbon atoms and a site derived from a vinyl compound having aliphatic hydrocarbon rings.

[0050] From the viewpoint of ensuring compatibility with the light-emitting material or coloring material and dispersing well, the content of the partial structure having high compatibility with the light-emitting material or coloring material in the copolymer is preferably 30% by weight or more, more preferably 50% by weight or more, and even more preferably 70% by weight or more, based on the total amount of the resin. On the other hand, the content of the partial structure having low compatibility with the light-emitting material or coloring material in the copolymer is preferably 70% by weight or less, more preferably 50% by weight or less, and even more preferably 30% by weight or less, based on the total amount of the resin.

[0051] Suitable examples of the resin include, but are not limited to, resins having a partial structure represented by general formula (1) and a partial structure represented by general formula (2) in the molecular structure.

[0052] [ka]

[0053] In general formula (1), Y 1 and Y 2 may be the same or different and are each a hydrogen atom or an organic group having 1 to 20 carbon atoms.

[0054] In general formula (2), Y 3 ~Y 6 may be the same or different, and each is a hydrogen atom or an organic group having 1 to 20 carbon atoms, and Y 3 ~Y 6 At least one of the groups is a group containing an aliphatic cyclic hydrocarbon structure.

[0055] Y is preferred because of its good copolymerization reactivity. 1 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group from the viewpoint of reducing the generation of radicals.

[0056] From the viewpoint of improving the heat resistance of resin, Y 2 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, or a heteroaryl group. These groups may be further substituted with the above-mentioned substituents. Among these, Y 2 is more preferably a methyl group or a cycloalkyl group, and even more preferably a methyl group from the viewpoint of compatibility with the light-emitting material or coloring material.

[0057] From the viewpoint of improving the heat resistance of resin, Y 3 ~Y 6 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, or a heteroaryl group. These groups may be further substituted with the above-mentioned substituents.

[0058] Y 3 ~Y 6 At least one of Y is a group containing an aliphatic cyclic hydrocarbon structure. There are no particular limitations on this, but from the viewpoint of availability and cost, 3 ~Y 6At least one of Y is preferably a substituted or unsubstituted cyclohexyl group. 3 ~Y 6 It is more preferable that one of the groups is a substituted or unsubstituted cyclohexyl group, and the other three are hydrogen atoms.

[0059] The content of the repeating unit of the partial structure represented by general formula (1) is not particularly limited, but is preferably 30% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, and particularly preferably 70% by weight or more, based on the total amount of the resin. By having the proportion of the repeating unit of the partial structure represented by general formula (1) within the above range, compatibility with the light-emitting material or coloring material can be ensured, and good dispersion can be achieved.

[0060] The content of the repeating unit of the partial structure represented by formula (1) is preferably 95% by weight or less, more preferably 90% by weight or less, and even more preferably 85% by weight or less, based on the total amount of the resin. By having the proportion of the repeating unit of the partial structure represented by formula (1) within the above range, compatibility with the light-emitting material or coloring material can be ensured, and good dispersion can be achieved.

[0061] The content of the repeating unit of the partial structure represented by formula (2) is preferably 5% by weight or more, more preferably 10% by weight or more, and particularly preferably 15% by weight or more, based on the total amount of the resin. By having the content of the repeating unit of the partial structure represented by formula (2) within the above range, compatibility with the light-emitting material or coloring material can be ensured, and good dispersion can be achieved.

[0062] The content of the repeating unit of the partial structure represented by formula (2) is preferably 70% by weight or less, more preferably 50% by weight or less, and even more preferably 30% by weight or less, based on the total amount of the resin. By having the proportion of the repeating unit of the partial structure represented by formula (2) within the above range, compatibility with the light-emitting material or coloring material can be ensured, and good dispersion can be achieved.

[0063] The resin can be obtained, for example, by a method of copolymerizing each raw material monomer in the presence of a polymerization initiator or a catalyst. Commercially available products can also be used. Commercially available resins include, for example, Optimas (registered trademark) 6500, Optimas (registered trademark) 7500, and Iupizeta (registered trademark) EP-5000 manufactured by Mitsubishi Gas Chemical Co., Ltd., and OKP (registered trademark) 4 and OKP (registered trademark)-A1 manufactured by Osaka Gas Chemical Co., Ltd., but are not limited thereto. In addition, resins disclosed in JP 2021-162621, JP 2022-116643, JP 2022-179996, JP 2022-72382, JP 2020-180184, JP 2018-53044, etc. can also be suitably used.

[0064] (luminescent or coloring material) The polymer particles according to the embodiment of the present invention preferably contain a light-emitting material or a coloring material therein.

[0065] The light-emitting material or coloring material preferably used in the present invention preferably has an absorption spectrum having at least one maximum peak in the wavelength range of 400 nm or more and 800 nm or less.

[0066] Specific examples of the light-emitting material or coloring material that can be suitably used in the present invention include inorganic fluorescent materials, fluorescent pigments, fluorescent dyes, quantum dots, etc. Two or more of these may be contained. Among them, it is more preferable to use organic pigments or organic dyes from the viewpoints of high dispersibility in resins, reduction in the amount used, and reduction in environmental load.

[0067] As organic pigments or dyes, for example: Compounds having a condensed aryl ring, such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, and derivatives thereof; Compounds having a heteroaryl ring, such as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, and pyrrolopyridine, and derivatives thereof; Borane derivatives; stilbene derivatives such as 1,4-distyrylbenzene, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, and 4,4'-bis(N-(stilben-4-yl)-N-phenylamino)stilbene; Aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives; Coumarin derivatives such as Coumarin 6, Coumarin 7, and Coumarin 153; azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and metal complexes thereof; Cyanine compounds such as indocyanine green; Xanthene and thioxanthene compounds such as fluorescein, eosin, and rhodamine; Polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and metal complexes thereof, porphyrin derivatives and metal complexes thereof; Oxazine compounds such as Nile Red and Nile Blue; Helicene-based compounds; Aromatic amine derivatives such as N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine; and Organometallic complex compounds of iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re); etc. are preferred.

[0068] Among these, perylene derivatives, xanthene compounds, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, phthalocyanine derivatives and metal complexes thereof, and porphyrin derivatives and metal complexes thereof are more preferable because of their large absorption coefficient and relatively high heat resistance.

[0069] (Method of Producing Polymer Microparticles) The method for producing polymer microparticles according to an embodiment of the present invention is a method which sequentially carries out the following steps (a) and (b). (a) The light transmittance is 85% or more in the wavelength range of 400 nm to 800 nm, and the intrinsic birefringence is -30 × 10 -4 Above +30×10 -4 A process for forming an emulsion containing two phases: a polymer phase (phase 1) containing a resin and an organic solvent, and a poor solvent phase (phase 2) containing a water-soluble polymer and water and / or alcohol. (b) A step of heating and / or reducing the pressure of the emulsion while stirring to remove a part or all of the organic solvent contained in the emulsion, thereby precipitating polymer fine particles.

[0070] In this method, polymer microparticles with the desired sphericity and linseed oil absorption can be produced because the polymer microparticles are extracted by removing the organic solvent through a homogeneous emulsion consisting of phase 1 and phase 2. Furthermore, polymer microparticles with the desired particle size and particle size distribution can be produced by adjusting the viscosity ratio of the dispersed phase to the continuous phase, the interfacial tension, and the applied stirring power.

[0071] The organic solvent has a light transmittance of 85% or more in the wavelength range of 400 nm to 800 nm and an inherent birefringence of -30 × 10 -4 Above +30×10 -4There are no particular limitations on the solvent, so long as it can dissolve the resin described below to form a polymer phase and separate into a water-soluble polymer and a poor solvent phase containing water and / or alcohol. Such a solvent can be appropriately selected, but an aprotic solvent is preferably used. Specific examples include hexane, cyclohexane, dioxane, toluene, diethyl ether, ethyl acetate, tetrahydrofuran, pyridine, ethylene glycol, acetonitrile, chloroform, and dichloromethane. Among these, hexane, cyclohexane, diethyl ether, ethyl acetate, tetrahydrofuran, acetonitrile, chloroform, and dichloromethane are more preferred in that they have a low boiling point and can selectively remove only the organic solvent in step (b), and hexane, cyclohexane, diethyl ether, ethyl acetate, chloroform, and dichloromethane are even more preferred in that they are less compatible with the poor solvent phase in step (a) and can form a stable emulsion, and cyclohexane, ethyl acetate, chloroform, and dichloromethane are particularly preferred in that they have excellent solubility of the resin.

[0072] The water-soluble polymer preferably used in the method for producing polymer microparticles according to the embodiment of the present invention is at least one selected from polyvinyl alcohol, poly(vinyl alcohol-ethylene) copolymer, polyethylene glycol, cellulose derivatives, and polyvinylpyrrolidones. Among these, polyvinyl alcohol, poly(vinyl alcohol-ethylene) copolymer, and polyethylene glycol are more preferred because they have excellent interfacial stabilization effect between the dispersed phase and the continuous phase and can form a homogeneous emulsion, and polyvinyl alcohol and polyethylene glycol are even more preferred because they are highly soluble in water and can be easily removed by washing.

[0073] In the method for producing polymer microparticles according to the embodiment of the present invention, the solvent that forms the poor solvent phase has a light transmittance of 85% or more in the wavelength range of 400 nm or more and 800 nm or less, and an intrinsic birefringence of −30×10 -4 Above +30×10 -4There are no particular limitations on the solvent, so long as it does not dissolve the resin described below, but dissolves the water-soluble polymer. Such a solvent can be appropriately selected, but examples include alcohols such as methanol, ethanol, and isopropanol, and water, with water being preferred from the viewpoint of preventing the generation of voids in the shaped product due to the organic solvent.

[0074] The obtained emulsion is heated and / or decompressed under stirring to remove part or all of the organic solvent contained in the emulsion, thereby precipitating polymer microparticles. There is no particular limitation on the method for selectively removing only the organic solvent. Specifically, there are a method of monitoring the vapor temperature by observing the temperature of the liquid distilled at an arbitrary reduced pressure, a method of observing the reduced pressure and the temperature of the reaction vessel and judging from the vapor pressure curve of the solvent, and a method of collecting the distilled liquid and analyzing it by GC, NMR, etc. The relationship between temperature and vapor pressure of each solvent can be calculated by Antoine's formula (see Revised 3rd Edition Chemistry Handbook Basics II p111-132, Edited by Japan Chemical Society, Maruzen Co., Ltd.). From the viewpoint of being able to observe the volatilization behavior of the solvent, a method of observing the vapor temperature is preferable.

[0075] The polymer microparticle solution thus obtained can be filtered using a conventional solid-liquid separation method such as filtration, and the resulting wet solid can be washed with a solvent such as water, if necessary, and then subjected to a drying process to obtain the desired dry powder.

[0076] (Composition and optical member) As one embodiment of the present invention, polymer particles can be mixed with a binder resin, a solvent, an additive, etc. to form a composition containing polymer particles. The composition according to the embodiment of the present invention can be molded into a desired shape according to the member to which it is applied. For example, a composition obtained by mixing polymer particles and a resin can be molded into a sheet shape, a lens shape, or other three-dimensional shape to produce a desired optical member. The molding method is not particularly limited as long as it can be molded into a desired shape, but examples of the molding method include a method of applying and drying using a known coating method, a method of molding using an extruder, and a three-dimensional additive manufacturing method using a 3D printer, etc.

[0077] Representative structural examples of the optical member according to the embodiment of the present invention include those shown in Figures 5 to 7. Figures 5 to 7 are schematic cross-sectional views showing examples of the optical member according to the embodiment of the present invention.

[0078] In the embodiment shown in FIG. 5, the optical member 1 has a structure in which polymer fine particles 2 are dispersed inside a support 3.

[0079] 6, the optical member 1 has a structure in which polymer fine particles 2a and polymer fine particles 2b are dispersed inside a support 3. The polymer fine particles 2a and 2b have different properties from each other, for example, emitting different luminescent colors from each other.

[0080] In the embodiment shown in FIG. 7, the optical member 1 has a structure in which a support 3a having polymer particles 2a dispersed therein and a support 3b having polymer particles 2b dispersed therein are laminated together.

[0081] The material of the support is not particularly limited and may be any known metal, resin, glass, ceramic, paper, etc. From the viewpoints of transparency and processability, the support is preferably made of resin.

[0082] One example of the optical member according to the embodiment of the present invention is a color conversion member that converts incident light into light of a different wavelength. The polymer particles of the present invention containing a luminescent material have small optical loss and excellent durability, and therefore can be suitably used.

[0083] Another example of the optical member according to the embodiment of the present invention is a color conversion substrate having a plurality of color conversion layers on a transparent substrate. In the present invention, the color conversion layer preferably includes a red conversion layer and a green conversion layer. The red conversion layer is formed of a phosphor material that absorbs at least blue light and emits red light. The green conversion layer is formed of a phosphor material that absorbs at least blue light and emits green light. In addition, a partition may be formed, and the color conversion layer is preferably disposed between the partitions (in a recess). The excitation light may be incident from the transparent substrate side and viewed from the side opposite to the transparent substrate, or the excitation light may be incident from the color conversion layer side and viewed from the transparent substrate side. The quantum yield of the color conversion layer is usually 0.5 or more, preferably 0.7 or more, more preferably 0.8 or more, and even more preferably 0.9 or more when the color conversion substrate is irradiated with blue light having a peak wavelength of 440 to 460 nm.

[0084] (light source) The light source according to the embodiment of the present invention is not particularly limited, and in principle, any light source can be used, such as a hot cathode tube, a cold cathode tube, a fluorescent light source such as an inorganic EL, an organic electroluminescence element light source, an LED light source, an incandescent light source, or sunlight. Among these, an LED is a suitable light source, and in display and lighting applications, a blue LED having a maximum emission in the range of 400 to 500 nm is a more suitable light source in terms of increasing the color purity of blue light. Furthermore, a blue LED having a maximum emission in the wavelength range of 430 nm to 480 nm is more preferable, and a blue LED having a maximum emission in the wavelength range of 450 nm to 470 nm is even more preferable.

[0085] The light source may have one emission peak or two or more emission peaks, but in order to improve color purity, it is preferable to have one emission peak. It is also possible to use multiple light sources with different emission peaks in any combination.

[0086] (Light source unit) The light source unit according to the embodiment of the present invention includes the above-mentioned light source and polymer fine particles or a member containing polymer fine particles. The light source unit of the present invention is useful for various light sources such as spatial illumination and backlighting, and can be used for applications such as displays, illumination, interiors, signs, and billboards, and is particularly suitable for use in displays and illumination.

[0087] (Displays, lighting equipment) The display according to the embodiment of the present invention includes at least a light source unit including a light source and polymer particles as described above. For example, the above light source unit is used as a backlight unit in a display such as a liquid crystal display.

[0088] Moreover, the lighting device according to the embodiment of the present invention includes at least a light source unit including a light source and polymer particles as described above. For example, the lighting device is configured to emit white light by combining a blue LED light source as a light source unit with polymer particles or a color conversion member containing the polymer particles that convert the blue light from the blue LED light source into light with a longer wavelength than the blue light.

[0089] (ink) The polymer microparticles of the present invention can also be used in ink. The ink according to the embodiment of the present invention is used for writing characters or coloring a surface in a liquid, gel, or solid state containing at least the polymer microparticles of the present invention. Since the polymer microparticles according to the embodiment of the present invention have high sphericity and a uniform shape, the use of the ink according to the embodiment of the present invention can increase the smoothness of the printed surface and suppress light scattering due to surface unevenness. In addition, since the polymer microparticles of the present invention are also excellent in durability, the use of the ink according to the embodiment of the present invention can enable the printed matter to be used for a long period of time. EXAMPLES

[0090] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0091] In the following Examples and Comparative Examples, compounds D-1 and D-2 are the compounds shown below.

[0092] [ka]

[0093] [Measurement and evaluation method] (1) Light transmittance of resin A sample piece with a thickness of 20 μm or less was prepared and measured using a commercially available measuring device (for example, a violet-visible spectrophotometer (product name U-3010) manufactured by Hitachi, Ltd.).

[0094] (2) Intrinsic birefringence of resin The dielectric polarization difference in the bond unit of each of the structural units was calculated by a molecular orbital method such as the AM1 method or PM3 method, and the intrinsic birefringence value was calculated as the volume average by the following Lorentz-Lorentz equation.

[0095]

number

[0096] In the above formula, Δn0: intrinsic birefringence value, ΔP: difference between the dielectric polarizability in the molecular chain axis direction and the dielectric polarizability in the direction perpendicular to the molecular chain axis, n: refractive index, d: density, N: Avogadro's number, and M: molecular weight.

[0097] (3) D50 particle size and D90 particle size / D10 particle size of polymer microparticles A dispersion of about 100 mg of polymer microparticles dispersed in about 5 mL of deionized water was added to a laser diffraction particle size distribution analyzer (Microtrac MT3300EX II) manufactured by Nikkiso Co., Ltd. until a measurable concentration was reached, and ultrasonic dispersion was performed in the analyzer at 30 W for 60 seconds, and the particle size at which the cumulative frequency from the small particle side of the particle size distribution measured in a measurement time of 10 seconds was 50% was taken as the D50 particle size. In addition, the particle sizes at which the cumulative frequency from the small particle side was 10% and 90% were taken as the D10 particle size and the D90 particle size, respectively, and the D90 particle size / D10 particle size was calculated from the ratio. The refractive index during measurement was 1.52, and the refractive index of the medium (deionized water) was 1.333.

[0098] (4) Sphericity of polymer particles The sphericity of the polymer microparticles was calculated from the minor axis and major axis of 30 randomly selected particles observed in a photograph taken with a scanning electron microscope (JSM-6301NF) manufactured by JEOL Ltd. according to the following formula.

[0099]

number

[0100] In the above formula, S is sphericity, a is major axis, b is minor axis, and n is the number of measurements (30).

[0101] (5) Linseed oil absorption of polymer microparticles In accordance with the Japanese Industrial Standards (JIS) K 5101 (2004) "Pigment Test Method - Refined Linseed Oil Method", approximately 300 mg of polymer microparticles was precisely weighed on a watch glass, refined linseed oil (Kanto Chemical Co., Ltd.) was gradually added drop by drop using a burette, and the mixture was kneaded with a palette knife. The drop-kneading process was repeated until a sample mass was formed, and the end point was the point at which the paste became smooth and hard. The oil absorption (mL / 100 g) was calculated from the amount of refined linseed oil used for dropping.

[0102] (6) Specific gravity of resin The specific gravity of the resin was calculated according to the Japanese Industrial Standards (JIS) JIS Z 8807 (2012) by placing about 10 g of sample and a solvent with a lower specific gravity than the sample in a Gay-Lussac type pycnometer, measuring the weights of the pycnometer only, pycnometer + sample, pycnometer + sample + solvent, and pycnometer + solvent, and using the following formula. The sample should be in the form of powder, pellet, or film.

[0103]

number

[0104] Here, d: specific gravity of the fine particles, d0: specific gravity of the solvent, Wa: weight of the pycnometer, Wb: weight of the pycnometer + sample, Wc: weight of the pycnometer + sample + solvent, and Wd: weight of the pycnometer + solvent.

[0105] (7) Glass transition temperature Using a TA Instruments differential scanning calorimeter (DSCQ20), the temperature was raised at a rate of 20°C / min from 30°C to a temperature 30°C higher than the endothermic peak indicating the melting point of the resin under a nitrogen atmosphere. In the DSC curve, the glass transition temperature was determined as the temperature at the point where a straight line equidistant in the vertical direction from the straight line extending the baselines on the low and high sides intersects with the curve of the stepwise change in the glass transition. In the case of an amorphous polymer that does not show a melting point peak, the DSC curve was obtained by raising the temperature from 30°C to 300°C. Approximately 8 mg of sample was required for the measurement.

[0106] (8) Light diffusion properties of powder The light diffusion properties of the filled powder were evaluated by the ratio of L values ​​at receiving angles of 0° and +45° measured at an incident angle of -45° using a goniospectrophotometer (GCMS-4 type) manufactured by Murakami Color Research Laboratory Co., Ltd. The sample powder was placed on adhesive tape, the powder was evenly applied to the adhesive part with the back of a spatula, and then the excess powder was removed with a cosmetic brush. The L values ​​at receiving angles of 0° and +45° were measured at an incident angle of -45° against a blank white board, and evaluated according to the following criteria: 〇: L(0°) / L(45°) is 0.50 or less. △: L(0°) / L(45°) is greater than 0.50 and less than 0.75. ×: L(0°) / L(45°) is greater than 0.75.

[0107] [Example 1] The resin used was polymethyl methacrylate-hydrogenated styrene copolymer resin "Optimas" (registered trademark) 7500 (manufactured by Mitsubishi Gas Chemical Co., Ltd., light transmittance in the wavelength range of 400 nm to 800 nm is 92%, inherent birefringence is -12 × 10 -4 , specific gravity 1.11g / cm 3 A 15% by mass polymer solution was prepared by mixing 45 g of 45% by mass of 1,2-dichlorophenyl ether (having a glass transition temperature of 120° C., a refractive index of 1.496, a partial structure represented by general formula (1) and a partial structure represented by general formula (2)) with 255 g of ethyl acetate as a solvent. In addition, 42 g of polyvinyl alcohol GL-05 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was dissolved in 258 g of water to prepare a 14% by mass aqueous polyvinyl alcohol solution. The polymer solution and the aqueous polyvinyl alcohol solution were added to a 1 L tank, and the mixture was stirred at 40° C. and 300 rpm to obtain an emulsion. Next, the 1 L tank was gradually reduced in pressure to 200 hPa using a diaphragm pump. After reaching 200 hPa, the pressure was reduced for another hour to remove the organic solvent in the emulsion, and a polymer microparticle slurry was obtained.

[0108] The polymer particle slurry was centrifuged and the supernatant was decanted to remove the solvent and the aqueous polyvinyl alcohol solution. The polymer particle slurry was then reslurried in water, washed with hot water at 80°C for 1 hour, and filtered to remove impurities in the particles, yielding a polymer particle cake. The polymer particle cake was dried under reduced pressure to obtain polymer particles with a yield of 90%. The properties and material properties of the obtained polymer particles are shown in Table 1. The obtained polymer particles were placed on a conductive tape and platinum was evaporated, and a photograph taken at a magnification of 5000 times using a scanning electron microscope (JSM-6301NF) manufactured by JEOL Ltd. is shown in Figure 1.

[0109] [Example 2] Except for using a 7% by mass aqueous polyvinyl alcohol solution prepared by dissolving 21 g of polyvinyl alcohol GL-05 in 279 g of water, polymer microparticles were prepared in the same manner as in Example 1. The properties and material properties of the obtained polymer microparticles are shown in Table 1.

[0110] [Comparative Example 1] A 200 mL tank was filled with polycarbonate (Idemitsu Kosan Co., Ltd.'s 'Toughlon (registered trademark)' A2200, light transmittance 85% in the wavelength range of 400 nm to 800 nm, intrinsic birefringence 1060 × 10 -4 , specific gravity 1.20g / cm 3 The mixture was heated to 80°C and stirred until the polymer was dissolved. While the temperature of the system was kept at 80°C and the mixture was stirred at 450 rpm, 100 g of ion-exchanged water was added dropwise at a speed of 1.64 g / min via a liquid pump. After the entire amount of water was added, the mixture was filtered, washed with 100 g of ion-exchanged water, and the filtered material was freeze-dried for 10 hours to obtain polymer microparticles. The properties and material properties of the obtained polymer microparticles are shown in Table 1.

[0111] [Comparative Example 2] Optimas (trademark) 7500 (manufactured by Mitsubishi Gas Chemical Co., Inc.) was used as a resin and frozen and crushed in a freezer mill to prepare polymer microparticles. The properties and material properties of the obtained polymer microparticles are shown in Table 1. As in Example 1, a photograph taken with a scanning electron microscope at a magnification of 200 times is shown in Figure 2.

[0112] [Example 3] Polymer microparticles were prepared in the same manner as in Example 1, except that 0.41 g of D-1 was added to the polymer solution, and luminescent agent-containing polymer microparticles were obtained in a yield of 92%. The properties and material properties of the obtained polymer microparticles are shown in Table 1. As in Example 1, a photograph taken with a scanning electron microscope at a magnification of 5000 times is shown in Figure 3.

[0113] [Example 4] Except for adding 0.01 g of D-2 to the polymer solution, light-emitting agent-containing polymer particles were prepared in the same manner as in Example 3. The properties and material properties of the obtained polymer particles are shown in Table 1.

[0114] [Comparative Example 3] As described in Example 1 of International Publication WO2020 / 050144, Optimas (trademark) 7500 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used as a resin, and 0.3 parts by mass of D-1 and 400 parts by mass of toluene as a solvent were mixed with respect to 100 parts by mass of this resin. These mixed solutions were stirred and degassed at 300 rpm for 30 minutes using a planetary stirring and degassing device "Mazerustar KK-400" (manufactured by Kurabo Industries, Ltd.). Polymer microparticles were produced by drying this mixed solution by a spray drying method. The characteristics and material properties of the obtained polymer microparticles are shown in Table 1. As in Example 1, a photograph taken with a scanning electron microscope at a magnification of 1000 times is shown in FIG. 3.

[0115] [Table 1]

Claims

1. The light transmittance is 85% or more in the wavelength range of 400 nm to 800 nm, and the intrinsic birefringence is -30 × 10⁻¹⁰. －４ The above + 30 x 10 －４ Polymer fine particles having the following resin as the main component, characterized in that the D50 particle size is 0.1 μm or more and 100 μm or less, and the sphericity is 80 or more and 100 or less.

2. The polymer fine particles according to claim 1, wherein the amount of linseed oil absorbed is 1 mL / 100 g or more and 200 mL / 100 g or less.

3. The polymer fine particles according to claim 1, wherein the D90 particle diameter / D10 particle diameter is 1.0 or more and 5.0 or less.

4. The specific gravity of the aforementioned resin is 1.15 g / cm³. ３ The polymer fine particles according to claim 1, which are as follows:

5. The polymer fine particles according to claim 1, wherein the glass transition temperature of the resin is 100°C or higher.

6. The polymer fine particles according to claim 1, further comprising a light-emitting material or a coloring material.

7. The polymer fine particles according to claim 6, wherein the absorption spectrum of the light-emitting material or coloring material has at least one maximum peak in the wavelength range of 400 nm to 800 nm.

8. A method for producing polymer fine particles, characterized by sequentially performing the following steps (a) and (b). (a) Light transmittance of 85% or more in the wavelength range of 400 nm to 800 nm, and intrinsic birefringence of -30 × 10 －４ The above + 30 x 10 －４ A step of forming an emulsion comprising two phases: a polymer phase containing the following resin and an organic solvent, and a poor solvent phase containing a water-soluble polymer and water and / or alcohol. (b) A step of heating and / or reducing the pressure of the emulsified liquid under stirring to volatilize and remove some or all of the organic solvent contained in the emulsified liquid, thereby precipitating polymer fine particles.

9. The method for producing polymer fine particles according to claim 8, wherein the water-soluble polymer is one or more selected from the group consisting of polyvinyl alcohol, poly(vinyl alcohol-ethylene) copolymer, polyethylene glycol, cellulose derivatives, and polyvinylpyrrolidones.

10. The method for producing polymer fine particles according to claim 8, wherein the organic phase further comprises a light-emitting material or a coloring material.

11. The method for producing polymer fine particles according to claim 10, wherein the absorption spectrum of the light-emitting material or coloring material has at least one maximum peak in the wavelength range of 400 nm to 800 nm.

12. A composition comprising a binder resin and polymer fine particles according to any one of claims 1 to 7.

13. An optical component comprising polymer fine particles according to any one of claims 1 to 7.

14. A light source unit comprising a light source and polymer fine particles according to claim 6 or 7.

15. A display comprising the light source unit described in claim 14.

16. A lighting device comprising the light source unit described in claim 14.

17. An ink comprising polymer fine particles according to claim 6 or 7.

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