Resin particles and circuit board with insulating layer

Abstract

The present invention provides resin particles which are capable of exhibiting low dielectric properties, while having enhanced dispersibility in a solvent and enhanced water repellency.　Resin particles according to the present invention each comprise a resin particle main body, and a plurality of polytetrafluoroethylene particles. The plurality of polytetrafluoroethylene particles are present only either on the surface of the resin particle main body or in the inside of the resin particle main body, or alternatively, are present both on the surface of the resin particle main body and in the inside of the resin particle main body. The resin particle main body is a polymer of a polymerizable component, and the polymerizable component comprises a polymerizable compound that has one or more ethylenically unsaturated groups.

Description

[Technical Field]

[0001] The present invention relates to resin particles containing polytetrafluoroethylene particles, and to a circuit board with an insulating layer using the resin particles. [Background technology]

[0002] Fluorine-based resins such as polytetrafluoroethylene (PTFE) are known to have excellent water repellency, chemical resistance, and low dielectric properties.

[0003] On the other hand, many particles containing fluororesin tend to aggregate easily and have a high specific gravity, making them difficult to disperse in a solvent, which poses a problem in that it is difficult to uniformly disperse and process particles containing fluororesin in a solvent.

[0004] Furthermore, a large amount of surfactant may be used to disperse particles containing fluororesin in a solvent, but the addition of a large amount of surfactant poses a problem of a large environmental load.

[0005] Patent Document 1 below discloses composite particles (C) containing particles (F) containing a fluorine-containing polymer (A) and a polymer (B) containing a monomer (b) as a constituent monomer. The composite particles (C) have a surface of the particles (F) coated with a coating layer containing the polymer (B). The composite particles (C) have an impregnation layer in which the polymer (B) is impregnated from the surface of the particles (F) to the inside. Patent Document 1 lists vinyl resins, epoxy resins, polyurethane resins, etc. as examples of the polymer (B). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-121352 Summary of the Invention [Problem to be solved by the invention]

[0007] In composite particles in which fluorine-containing particles are coated with a urethane resin or the like, as described in Patent Document 1, the fluorine-based resin is coated with a polymer, and therefore the excellent water repellency and low dielectric properties of the fluorine-based resin may not be fully exhibited. Furthermore, in conventional composite particles such as those described in Patent Document 1, the composite particles may form unintended aggregates due to stimuli such as stirring, heating, or reaction during molding of the composite particles. As a result, the dispersibility of the composite particles in a solvent may not be sufficiently improved.

[0008] That is, it is difficult for conventional composite particles containing fluorine-based resins to have improved dispersibility in a solvent, improved water repellency, and low dielectric properties.

[0009] An object of the present invention is to provide resin particles that can enhance dispersibility in solvents, enhance water repellency, and exhibit low dielectric properties, and a circuit board with an insulating layer that uses the resin particles. [Means for solving the problem]

[0010] This specification discloses the following resin particles and circuit board with an insulating layer.

[0011] Item 1. Resin particles comprising a resin particle body and a plurality of polytetrafluoroethylene particles, wherein the plurality of polytetrafluoroethylene particles are present either on the surface of the resin particle body or inside the resin particle body, or both on the surface of the resin particle body and inside the resin particle body, the resin particle body being a polymer of a polymerizable component, and the polymerizable component containing a polymerizable compound having one or more ethylenically unsaturated groups.

[0012] Item 2. The resin particles according to Item 1, wherein the polytetrafluoroethylene particles have a particle diameter of 10 nm or more and 500 nm or less.

[0013] Item 3. The resin particles according to Item 1 or 2, wherein the particle diameter of the resin particles is 0.5 μm or more.

[0014] Item 4. The resin particles according to any one of Items 1 to 3, wherein the CV value of the particle diameter of the resin particles is 30% or less.

[0015] Item 5. The resin particles according to any one of Items 1 to 4, wherein the resin particles have an aspect ratio of 1.5 or less.

[0016] Item 6. The resin particles according to any one of Items 1 to 5, wherein the resin particles have a specific gravity of 1.6 or less.

[0017] Item 7. The resin particles according to any one of Items 1 to 6, wherein the content of the polytetrafluoroethylene particles is 0.01% by weight or more and 35% by weight or less in 100% by weight of the resin particles.

[0018] Item 8. The resin particles according to any one of Items 1 to 7, wherein the resin particles have a dielectric constant of 2.60 F / m or less.

[0019] Item 9. The resin particles according to any one of Items 1 to 8, wherein the resin particles have a dielectric loss tangent of less than 0.010.

[0020] Item 10. The resin particles according to any one of Items 1 to 9, wherein in at least one of the plurality of polytetrafluoroethylene particles, a portion of the polytetrafluoroethylene particle is present inside the resin particle body, and a portion of the polytetrafluoroethylene particle is present on the surface of the resin particle body.

[0021] Item 11. The resin particle according to any one of Items 1 to 10, wherein the number of the polytetrafluoroethylene particles present in a region extending from the surface of the resin particle body to half the thickness toward the center is greater than the number of the polytetrafluoroethylene particles present in a region extending from the center of the resin particle body to half the thickness toward the surface.

[0022] Item 12. A circuit board with an insulating layer, comprising a circuit board and an insulating layer disposed on a surface of the circuit board, the insulating layer containing the resin particles according to any one of items 1 to 11. [Effects of the Invention]

[0023] The resin particles according to the present invention comprise a resin particle body and a plurality of polytetrafluoroethylene particles. In the resin particles according to the present invention, the plurality of polytetrafluoroethylene particles are present either on the surface of the resin particle body or inside the resin particle body, or both on the surface of the resin particle body and inside the resin particle body. In the resin particles according to the present invention, the resin particle body is a polymer of a polymerizable component, and the polymerizable component contains a polymerizable compound having one or more ethylenically unsaturated groups. Because the resin particles according to the present invention have the above-described configuration, they can have improved dispersibility in solvents, improved water repellency, and exhibit low dielectric properties. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a resin particle according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a resin particle according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view schematically showing a multilayer printed wiring board using resin particles according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be described in detail below. In this specification, for example, "(meth)acryloxy" means one or both of "acryloxy" and "methacryloxy", and "(meth)acrylic" means one or both of "acrylic" and "methacrylic".

[0026] (resin particles) The resin particles according to the present invention comprise a resin particle body and a plurality of polytetrafluoroethylene particles. In the resin particles according to the present invention, the plurality of polytetrafluoroethylene particles are present either on the surface of the resin particle body or inside the resin particle body, or both on the surface of the resin particle body and inside the resin particle body. In the resin particles according to the present invention, the resin particle body is a polymer of a polymerizable component, and the polymerizable component contains a polymerizable compound having one or more ethylenically unsaturated groups.

[0027] The resin particles according to the present invention have the above-described structure, which allows for improved dispersibility in a solvent. As a result, when the resin particles according to the present invention are dispersed in a solvent, the resin particles do not form unintended aggregates, thereby improving inkjet ejection properties and improving molding stability when molding a composition containing the resin particles. Furthermore, the resin particles according to the present invention do not require the addition of a large amount of surfactant to disperse them in a solvent, which reduces environmental impact, suppresses bleed-out caused by the surfactant, and prevents peeling of the resin particles from a molded product of a composition containing the resin particles. Furthermore, the resin particles according to the present invention have the above-described structure, which allows for improved water repellency and low dielectric properties.

[0028] In the resin particles according to the present invention, a plurality of the polytetrafluoroethylene particles may be present on the surface (external) of the resin particle body, may be present inside the resin particle body, or may be present on the surface (external) and internal of the resin particle body.Furthermore, in the resin particles according to the present invention, a plurality of the polytetrafluoroethylene particles may be present at least on the surface (external) of the resin particle body, or may be present at least internally of the resin particle body.

[0029] In the resin particles, any one of the polytetrafluoroethylene particles may be entirely present on the surface (exterior) of the resin particle body, or a portion of any one of the polytetrafluoroethylene particles may be present (exposed) on the surface (exterior) of the resin particle body. In the resin particles, any one of the polytetrafluoroethylene particles may be entirely present inside the resin particle body, or a portion of any one of the polytetrafluoroethylene particles may be present inside the resin particle body.

[0030] In the resin particles, all of the polytetrafluoroethylene particles may be present on the surface (exterior) of the resin particle body, or a portion (at least one) of the polytetrafluoroethylene particles may be present on the surface (exterior) of the resin particle body. In the resin particles, all of the polytetrafluoroethylene particles may be present on the surface (exterior) of the resin particle body, or at least one of the polytetrafluoroethylene particles may be present on the surface (exterior) of the resin particle body. In the resin particles, all of the polytetrafluoroethylene particles may be present inside the resin particle body, or a portion (at least one) of the polytetrafluoroethylene particles may be present inside the resin particle body. In the resin particles, all of the polytetrafluoroethylene particles may be present inside the resin particle body, or at least one of the polytetrafluoroethylene particles may be present inside the resin particle body.

[0031] The resin particles may contain polytetrafluoroethylene particles present on the surface (exterior) of the resin particle body, polytetrafluoroethylene particles present on the surface (exterior) and interior of the resin particle body (parts of which are present exterior to the resin particle body), and polytetrafluoroethylene particles present interior to the resin particle body. From the viewpoint of further enhancing water repellency, it is preferred that in at least one of the plurality of polytetrafluoroethylene particles, a part of the polytetrafluoroethylene particles is present interior to the resin particle body, and a part of the polytetrafluoroethylene particles is present (exposed) on the surface (exterior) of the resin particle body. From the viewpoint of further enhancing water repellency, it is preferred that in some (at least one) of the polytetrafluoroethylene particles, a part of the polytetrafluoroethylene particles is present interior to the resin particle body, and a part of the polytetrafluoroethylene particles is present (exposed) on the surface (exterior) of the resin particle body. In the resin particles, it is preferable that the polytetrafluoroethylene particles exist only on the surface (outside) of the resin particle body, the polytetrafluoroethylene particles exist on the surface and inside of the resin particle body (parts of which exist outside the resin particle body), and the polytetrafluoroethylene particles exist only inside the resin particle body. In these cases, the water repellency can be further improved and the low dielectric property can be more effectively exhibited.

[0032] The present invention will be specifically described below with reference to the drawings.

[0033] FIG. 1 is a cross-sectional view schematically showing a resin particle according to a first embodiment of the present invention.

[0034] 1 includes a resin particle body 2 and a plurality of polytetrafluoroethylene particles 3. In the resin particle 1, all of the polytetrafluoroethylene particles 3 are present on the surface (exterior) and inside of the resin particle body 2. In the resin particle 1, a portion of all of the polytetrafluoroethylene particles 3 is present inside the resin particle body 2, and a portion of the polytetrafluoroethylene particles 3 is present on the surface (exterior) of the resin particle body 2.

[0035] FIG. 2 is a cross-sectional view schematically showing a resin particle according to a second embodiment of the present invention.

[0036] A resin particle 1A shown in FIG. 2 includes a resin particle body 2 and a plurality of polytetrafluoroethylene particles 3A. In the resin particle 1A, at least one of the plurality of polytetrafluoroethylene particles 3A is present inside the resin particle body 2. In the resin particle 1A, a portion (at least one) of the polytetrafluoroethylene particles 3A is present inside the resin particle body 2. In the resin particle 1A, a plurality of polytetrafluoroethylene particles 3A are dispersed in the resin particle body 2. In the resin particle 1A, a plurality of polytetrafluoroethylene particles 3A are present on the surface (exterior) and interior of the resin particle body 2. In the resin particle 1A, a portion (at least one) of the polytetrafluoroethylene particles 3A is present on the surface (exterior) and interior of the resin particle body 2. In the resin particle 1A, at least one of the plurality of polytetrafluoroethylene particles 3A has a portion of the polytetrafluoroethylene particle 3A present inside the resin particle body 2 and a portion of the polytetrafluoroethylene particle 3A present on the surface (exterior) of the resin particle body 2.

[0037] In the resin particle 1A, polytetrafluoroethylene particles 3A that are entirely present inside the resin particle body 2 and polytetrafluoroethylene particles 3A that are partially present on the surface (outside) of the resin particle body 2 are present.

[0038] The dielectric constant of the resin particles is preferably 2.60 F / m or less, more preferably 2.50 F / m or less, even more preferably 2.40 F / m or less, particularly preferably 2.35 F / m or less, and most preferably 2.30 F / m or less. When the dielectric constant of the resin particles is equal to or less than the above upper limit, low dielectric properties can be more effectively exhibited. The lower limit of the dielectric constant of the resin particles is not particularly limited. The dielectric constant of the resin particles may be 1.80 F / m or more, or may be 1.90 F / m or more. The range of the dielectric constant of the resin particles can be set by appropriately selecting the above lower limit and upper limit.

[0039] The dielectric loss tangent of the resin particles is preferably 0.010 or less, preferably less than 0.010, more preferably 0.006 or less, more preferably less than 0.006, even more preferably 0.005 or less, particularly preferably 0.003 or less, particularly preferably less than 0.003, and most preferably 0.001 or less. When the dielectric loss tangent of the resin particles is equal to or less than the above upper limit (less than), low dielectric properties can be more effectively exhibited. The lower limit of the dielectric loss tangent of the resin particles is not particularly limited. The dielectric loss tangent of the resin particles may be 0.0001 or more, or may be 0.0005 or more. The range of the dielectric loss tangent of the resin particles can be set by appropriately selecting the above lower limit and upper limit.

[0040] The dielectric constant and dielectric loss tangent of the resin particles can be measured, for example, as follows: A quartz tube is filled with resin particles and placed in a powder measurement resonator. The dielectric constant and dielectric loss tangent of the resin particles at 1 GHz are measured using a dielectric constant measuring device (manufactured by AET).

[0041] The 10% K value of the resin particles at 25°C is preferably 100 N / mm 2 More preferably, 500N / mm 2 More preferably, 1000N / mm 2 or more, preferably 20,000 N / mm 2 Less than or equal to 15,000 N / mm 2 or less, more preferably 10,000 N / mm 2Below 8000N / mm 2 When the 10% K value at 25° C. of the resin particles is equal to or greater than the above lower limit and equal to or less than the above upper limit, interfacial peeling between the polytetrafluoroethylene particles and the resin particle bodies can be suppressed.

[0042] The 10% K value of the resin particles at 25°C can be measured as follows. Using a microcompression tester, the resin particles are compressed with a smooth cylindrical indenter end face (diameter 50 μm, made of diamond) at 25°C under conditions where a maximum test load of 20 mN is applied for 60 seconds. The load value (N) and compression displacement (mm) at this time are measured. From the obtained measured values, the 10% K value of the resin particles at 25°C can be calculated using the following formula. As the microcompression tester, for example, a Fischerscope H-100 manufactured by Fischer can be used.

[0043] 10% K value (N / mm 2 )=(3 / 2 1 / 2 )·F·S -3 / 2 ·R -1 / 2 F: Load value (N) when resin particles are compressed and deformed by 10% S: Compression displacement (mm) when resin particles are compressed by 10% R: Radius of resin particle (mm)

[0044] From the viewpoint of suppressing crushing of the resin particles when molding a composition containing the resin particles, the compression recovery rate of the resin particles at 25°C is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more, and is preferably 95% or less, more preferably 90% or less, and even more preferably 80% or less. The compression recovery rate of the resin particles at 25°C may be 70% or less.

[0045] The compression recovery rate of the resin particles at 25° C. can be measured as follows.

[0046] Resin particles are scattered on a sample stage. A microcompression tester is used to apply a load to each scattered resin particle with the end face of a smooth cylindrical indenter (50 μm diameter, made of diamond) at 25°C toward the center of the resin particle under conditions of an origin load of 1.0 mN and a reverse load of 10 mN. The recovery behavior after the load is removed is analyzed to derive the compression recovery rate. The load-compression displacement during this period is measured, and the compression recovery rate can be calculated using the following formula. The loading rate is 0.33 mN / sec. The microcompression tester may be, for example, the Fischerscope H-100 manufactured by Fischer.

[0047] Compression recovery rate (%) = [L2 / L1] x 100 L1: Compression displacement from the load value for the origin to the reverse load value when applying a load L2: Unloading displacement from the reverse load value when releasing the load to the load value for the origin

[0048] The particle size of the resin particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 3.0 μm or more, and particularly preferably 5.0 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, even more preferably 20 μm or less, particularly preferably 15 μm or less, and most preferably 10 μm or less. When the particle size of the resin particles is not less than the above lower limit and not more than the above upper limit, the dispersibility of the resin particles in a solvent can be further improved.

[0049] The particle size of the resin particles means the diameter when the resin particles are spherical, and when the resin particles are other than spherical, means the diameter when the resin particles are assumed to be spherical with a volume equivalent to that of the resin particles.

[0050] The particle size of the resin particles is preferably an average particle size, and more preferably a number-average particle size. The particle size of the resin particles can be measured using any particle size distribution measuring device. For example, it can be measured using a particle size distribution measuring device that uses the principles of laser light scattering, electrical resistance change, image analysis after imaging, etc. More specifically, a method for measuring the particle size of the resin particles includes measuring the particle sizes of approximately 100,000 resin particles using a particle size distribution measuring device (Beckman Coulter's "Multisizer 4") and calculating the average value.

[0051] From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the coefficient of variation (CV value) of the particle diameter of the resin particles is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, even more preferably 20% or less, particularly preferably 15% or less, and most preferably 10% or less. The lower limit of the coefficient of variation (CV value) of the particle diameter of the resin particles is not particularly limited. The coefficient of variation (CV value) of the particle diameter of the resin particles may be 0% or more or may be 1% or more. The range of the coefficient of variation (CV value) of the particle diameter of the resin particles can be set by appropriately selecting the lower limit and the upper limit.

[0052] The coefficient of variation (CV value) of the particle diameter of the resin particles can be measured as follows.

[0053] CV value (%) of the particle diameter of the resin particles = (ρ / Dn) × 100 ρ: Standard deviation of the particle size of the resin particles Dn: average particle size of the resin particles

[0054] The shape of the resin particles is not particularly limited. The shape of the resin particles may be spherical, may be a shape other than spherical, or may be flat. From the viewpoint of further improving the dispersibility of the resin particles in a solvent, the shape of the resin particles is preferably spherical.

[0055] From the viewpoint of further enhancing the dispersibility of the resin particles in the solvent, the aspect ratio of the resin particles is preferably 1.5 or less, more preferably 1.4 or less, even more preferably 1.3 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less. The lower limit of the aspect ratio of the resin particles is not particularly limited. The aspect ratio of the resin particles may be 1.0 or more, or may be 1.1 or more. From the viewpoint of further enhancing the dispersibility of the resin particles in the solvent, the aspect ratio of the resin particles is most preferably 1.0. The range of the aspect ratio of the resin particles can be set by appropriately selecting the lower limit and the upper limit.

[0056] The aspect ratio is expressed as the ratio of major axis to minor axis, and is preferably determined by observing 10 arbitrary resin particles under an electron microscope or an optical microscope, defining the maximum diameter and the minimum diameter as the major axis and the minor axis, respectively, and calculating the average value of the major axis / minor axis of each of the spherical resin particles.

[0057] To prevent the resin particles from settling in the solvent and further enhance the dispersibility of the resin particles in the solvent, the specific gravity of the resin particles is preferably 1.6 or less, more preferably 1.5 or less, even more preferably 1.4 or less, and particularly preferably 1.3 or less. The specific gravity of the resin particles may be 0.8 or more, 0.9 or more, or 1.0 or more. The range of the specific gravity of the resin particles can be set by appropriately selecting the lower limit and the upper limit.

[0058] The resin particles are preferably used by dispersing them in a solvent. The resin particles are preferably used as a composition by dispersing them in a solvent. The solvent for dispersing the resin particles may be aqueous or oil-based. Examples of solvents for dispersing the resin particles include silicone, water, mineral oil, polyether derivatives; alcohols such as methanol, ethanol, isopropanol, and fluorine-containing alcohols; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, diethyl ether, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, and cyclic ethers; esters such as acetate esters, pyruvate esters, 2-hydroxyisobutyric acid, and lactate esters; amides such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as octane and decane; and resins. Examples of the resins include rubber, vinyl resins, acrylic resins, urethane resins, melamine resins, polyester resins, polyol resins, engineering plastics, silicone resins, fluororesins, and epoxy resins. When the resin particles are used in a liquid state by dispersing them in a solvent, the solvent is preferably silicone, water, mineral oil, polyether derivatives, or the like. Compositions in which the resin particles are dispersed in these solvents are particularly suitable for use as lubricants, anti-tack agents, etc. When the resin particles are dispersed in a solvent and then the solvent is evaporated for use, the solvent is preferably an alcohol such as methanol, ethanol, isopropanol, or a fluorine-containing alcohol; a ketone such as acetone or methyl ethyl ketone; an ether such as tetrahydrofuran, diethyl ether, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, or a cyclic ether; an ester such as acetate ester, pyruvate ester, 2-hydroxyisobutyric acid, or lactate ester; an amide such as dimethylformamide; an aromatic hydrocarbon such as toluene or xylene; an aliphatic hydrocarbon such as octane or decane; or water. Compositions in which the resin particles are dispersed in these solvents are particularly suitable for use in inks, coating agents, paints, photoreceptors, etc.The composition in which the resin particles are dispersed in the resin is particularly suitable for use as a coating agent, paint, non-tackifier, anti-drip agent, and the like.

[0059] The composition containing the resin particles and a solvent may be applied using an inkjet device, screen printing, or a dispensing method. Generally, conventional composite particles containing fluorine-based resins tend to settle when dispersed in a solvent, making it difficult to improve inkjet ejection properties. On the other hand, the resin particles have the above-described structure, and therefore can improve inkjet ejection properties when dispersed in a solvent.

[0060] From the viewpoint of further enhancing the dispersibility of the resin particles in the solvent, the specific gravity of the solvent in which the resin particles are dispersed is preferably 0.5 or more, more preferably 0.7 or more, even more preferably 0.8 or more, and preferably 1.5 or less, more preferably 1.4 or less, even more preferably 1.3 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less.

[0061] From the viewpoint of further enhancing the dispersibility of the resin particles in the solvent, the resin particles are preferably dispersed in toluene or an epoxy resin before use.

[0062] Each component of the resin particles will be described in detail below.

[0063] <Resin particle body> The resin particles have a resin particle body. The resin particles and the resin particle body contain a resin. In the resin particles, the resin particle body is a polymer of a polymerizable component. The polymerizable component contains a polymerizable compound having one or more ethylenically unsaturated groups. The polymerizable component preferably contains a polymerizable compound having two or more ethylenically unsaturated groups. The resin particle body preferably contains a polymer of a polymerizable compound having one or more ethylenically unsaturated groups. The resin particle body preferably contains a polymer of a polymerizable compound having two or more ethylenically unsaturated groups.

[0064] Examples of the polymerizable compound (monomer) having one or more ethylenically unsaturated groups include a polymerizable compound having one ethylenically unsaturated group and a polymerizable compound having two or more ethylenically unsaturated groups. The polymerizable compound having two or more ethylenically unsaturated groups may have 100 or less ethylenically unsaturated groups, or may have 10 or less ethylenically unsaturated groups. The polymerizable compound having one or more ethylenically unsaturated groups may be used alone or in combination of two or more. The polymerizable compound having one ethylenically unsaturated group may be used alone or in combination of two or more. The polymerizable compound having two or more ethylenically unsaturated groups may be used alone or in combination of two or more.

[0065] The polymerizable compound (monomer) having one or more ethylenically unsaturated groups includes a non-crosslinkable monomer and a crosslinkable monomer. The polymerizable compound (monomer) having one or more ethylenically unsaturated groups may be a polymerizable compound having one or more maleimide groups.

[0066] Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, and polyoxyethylene (meth)acrylate. nitrile-containing monomers such as (meth)acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; acid vinyl esters such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogen-containing monomers such as trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, (perfluorohexyl)ethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene; and polymerizable compounds having one maleimide group.

[0067] Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, and (poly)propylene glycol di(meth)acrylate. Examples of suitable polymerizable compounds include polyfunctional (meth)acrylates such as (meth)acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate; silane-containing monomers such as triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane; and polymerizable compounds having two or more maleimide groups. The polymerizable compound having two or more maleimide groups may be a polymerizable compound having two maleimide groups or a bismaleimide compound. The polymerizable compound having two or more maleimide groups may have 100 or less maleimide groups, or may have 10 or less maleimide groups.

[0068] The polymerizable compound (polymerizable component) having one or more ethylenically unsaturated groups preferably includes styrene, divinylbenzene, 2-(perfluorohexyl)ethyl (meth)acrylate, methyl (meth)acrylate, (poly)ethylene glycol di(meth)acrylate, or a polymerizable compound having a maleimide group. In this case, the effects of the present invention can be effectively exhibited. From the viewpoint of more effectively exhibiting the effects of the present invention, the polymerizable compound (polymerizable component) having one or more ethylenically unsaturated groups more preferably includes styrene, divinylbenzene, methyl (meth)acrylate, or (poly)ethylene glycol di(meth)acrylate, and even more preferably includes styrene or divinylbenzene. From the viewpoint of even more effectively exhibiting the effects of the present invention, the polymerizable compound (polymerizable component) having one or more ethylenically unsaturated groups more preferably includes styrene and divinylbenzene. In these cases, the dispersibility of polytetrafluoroethylene particles in the resin particle body can be improved, the water repellency of the resin particles can be further improved, and the low dielectric properties of the resin particles can be more effectively exhibited.

[0069] From the viewpoint of improving solvent resistance and chemical resistance, the resin particle body preferably contains a copolymer of styrene and divinylbenzene.

[0070] The resin particle bodies can be obtained by polymerizing the polymerizable compound having one or more ethylenically unsaturated groups by a known method, such as a suspension polymerization method in the presence of a radical polymerization initiator, or a method in which a polymerizable compound is swelled and polymerized together with a radical polymerization initiator using non-crosslinked seed particles.

[0071] The particle diameter of the resin particle body is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 3.0 μm or more, and particularly preferably 5.0 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, even more preferably 20 μm or less, particularly preferably 15 μm or less, and most preferably 10 μm or less. When the particle diameter of the resin particle body is not less than the above lower limit and not more than the above upper limit, the dispersibility of the resin particles in solvents and the water repellency can be further improved.

[0072] The particle diameter of the resin particle body means the diameter when the resin particle body is spherical, and when the resin particle body has a shape other than spherical, means the diameter when assumed to be a perfect sphere of equivalent volume.

[0073] The particle diameter of the resin particle body is preferably an average particle diameter, and more preferably a number average particle diameter. The particle diameter of the resin particle body can be measured using any particle size distribution measuring device. For example, it can be measured using a particle size distribution measuring device that uses principles such as laser light scattering, electrical resistance change, or image analysis after imaging. More specifically, as a method for measuring the particle diameter of the resin particle body, a particle size distribution measuring device (Beckman Coulter's "Multisizer 4") can be used to measure the particle diameter of approximately 100,000 resin particle bodies and calculate the average particle diameter.

[0074] From the viewpoint of further improving the dispersibility of the resin particles in a solvent, the coefficient of variation (CV value) of the particle diameter of the resin particle body is preferably 35% or less, more preferably 30% or less, even more preferably 25% or less, even more preferably 20% or less, particularly preferably 15% or less, and most preferably 10% or less. The lower limit of the coefficient of variation (CV value) of the particle diameter of the resin particle body is not particularly limited. The coefficient of variation (CV value) of the particle diameter of the resin particle body may be 0% or more or may be 1% or more. The range of the coefficient of variation (CV value) of the particle diameter of the resin particle body can be set by appropriately selecting the lower limit and the upper limit.

[0075] The coefficient of variation (CV value) of the particle diameter of the resin particle body can be measured as follows.

[0076] CV value (%) of the particle diameter of the resin particle body = (ρ / Dn) × 100 ρ: Standard deviation of the particle diameter of the resin particle body Dn: average particle diameter of the resin particle body

[0077] The shape of the resin particle body is not particularly limited, and may be spherical, or may be a shape other than spherical, such as flat.

[0078] The content of the resin particle body in 100% by weight of the resin particles is preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, and most preferably 95% by weight or more, and is preferably 99.99% by weight or less, more preferably 99.9% by weight or less, even more preferably 99% by weight or less, and particularly preferably 98% by weight or less. When the content of the resin particle body is above the above lower limit and below the above upper limit, the dispersibility of the resin particles in a solvent can be further improved. The content of the resin particle body in 100% by weight of the resin particles may be 95% by weight or less, or may be 90% by weight or less.

[0079] The content of the polymerizable compound having one or more ethylenically unsaturated groups in 100% by weight of the polymerizable component is preferably 80% by weight or more, more preferably 85% by weight or more, even more preferably 90% by weight or more, and particularly preferably 95% by weight or more. When the content of the polymerizable compound having one or more ethylenically unsaturated groups is equal to or greater than the lower limit, solvent resistance and chemical resistance can be improved. The upper limit of the content of the polymerizable compound having one or more ethylenically unsaturated groups in 100% by weight of the polymerizable component may be 100% by weight (total amount) or less than 100% by weight. The range of the content of the polymerizable compound having one or more ethylenically unsaturated groups in 100% by weight of the polymerizable component can be set by appropriately selecting the lower limit and the upper limit.

[0080] The content of the polymerizable compound having two or more ethylenically unsaturated groups in 100% by weight of the polymerizable component is preferably 80% by weight or more, more preferably 85% by weight or more, even more preferably 90% by weight or more, and particularly preferably 95% by weight or more. When the content of the polymerizable compound having two or more ethylenically unsaturated groups is equal to or greater than the lower limit, solvent resistance and chemical resistance can be improved. The upper limit of the content of the polymerizable compound having two or more ethylenically unsaturated groups in 100% by weight of the polymerizable component may be 100% by weight (total amount) or less than 100% by weight. The range of the content of the polymerizable compound having two or more ethylenically unsaturated groups in 100% by weight of the polymerizable component can be set by appropriately selecting the lower limit and the upper limit.

[0081] <Polytetrafluoroethylene particles> The resin particles include a plurality of polytetrafluoroethylene particles (PTFE particles).

[0082] In polytetrafluoroethylene particles in which a portion of the polytetrafluoroethylene particles exists on the surface (external) of the resin particle body, the volume of the portion existing on the surface (external) of the resin particle body in 100% by volume of the polytetrafluoroethylene particles is preferably 0.01% by volume or more, more preferably 0.1% by volume or more, even more preferably 1% by volume or more, even more preferably 5% by volume or more, even more preferably 10% by volume or more, particularly preferably 20% by volume or more, most preferably 30% by volume or more, and preferably 99% by volume or less, more preferably 95% by volume or less, even more preferably 90% by volume or less, particularly preferably 85% by volume or less, most preferably 80% by volume or less. When the volume of the portion existing on the surface (external) of the resin particle body is above the above lower limit and below the above upper limit, the dispersibility of the resin particles in solvents can be further improved and the water repellency can be further improved.

[0083] From the viewpoint of further improving dispersibility, in the resin particles, the number of polytetrafluoroethylene particles present on the surface (exterior) of the resin particle body, out of the total number of polytetrafluoroethylene particles (100%), is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and preferably 100% or less. Note that when a single polytetrafluoroethylene particle is observed, if all or a part of the polytetrafluoroethylene particle is present (exposed) on the surface (exterior) of the resin particle body, the polytetrafluoroethylene particle is judged to correspond to the polytetrafluoroethylene particle present on the surface (exterior) of the resin particle body. When a single polytetrafluoroethylene particle is observed, if at least a part of the polytetrafluoroethylene particle is present (exposed) on the surface (exterior) of the resin particle body, the polytetrafluoroethylene particle is judged to correspond to the polytetrafluoroethylene particle present on the surface (exterior) of the resin particle body. When a single polytetrafluoroethylene particle is observed, if the entire polytetrafluoroethylene particle is not present on the surface (outside) of the resin particle body, the polytetrafluoroethylene particle is determined not to correspond to a polytetrafluoroethylene particle present on the surface (outside) of the resin particle body.

[0084] In the resin particles, the polytetrafluoroethylene particles may be dispersed on the surface (external) of the resin particle body, or may be unevenly distributed. From the viewpoint of further enhancing water repellency and more effectively exhibiting low dielectric properties, it is preferable that the polytetrafluoroethylene particles are dispersed on the surface (external) of the resin particle body.

[0085] The particle size of the polytetrafluoroethylene particles is preferably 10 nm or more, more preferably 20 nm or more, even more preferably 100 nm or more, and is preferably 500 nm or less, more preferably 400 nm or less, even more preferably 350 nm or less. When the particle size of the polytetrafluoroethylene particles is equal to or more than the above lower limit and equal to or less than the above upper limit, aggregation of the polytetrafluoroethylene particles on the surface or inside of the resin particle body can be suppressed.

[0086] The particle size of the polytetrafluoroethylene particles is preferably equal to or smaller than the particle size of the resin particles, and more preferably smaller than the particle size of the resin particles. The ratio of the particle size of the polytetrafluoroethylene particles to the particle size of the resin particles is referred to as the ratio (particle size of polytetrafluoroethylene particles / particle size of resin particles). The ratio (particle size of polytetrafluoroethylene particles / particle size of resin particles) is preferably 0.001 or more, more preferably 0.01 or more, even more preferably 0.03 or more, and preferably 0.5 or less, more preferably 0.3 or less, even more preferably 0.1 or less, and particularly preferably 0.06 or less. When the ratio (particle size of polytetrafluoroethylene particles / particle size of resin particles) is equal to or greater than the lower limit and equal to or less than the upper limit, aggregation of polytetrafluoroethylene particles on the surface or inside the resin particle body can be suppressed.

[0087] The particle size of the polytetrafluoroethylene particles means the diameter when the polytetrafluoroethylene particles are spherical, and when the polytetrafluoroethylene particles are in a shape other than spherical, means the diameter when the particles are assumed to be spherical with a volume equivalent to that of the particles.

[0088] The particle size of the polytetrafluoroethylene particles is preferably an average particle size, and more preferably a number average particle size. The particle size of the polytetrafluoroethylene particles can be measured using any particle size distribution measuring device. For example, it can be measured using a particle size distribution measuring device that uses the principles of laser light scattering, electrical resistance change, image analysis after imaging, etc. More specifically, as a method for measuring the particle size of polytetrafluoroethylene particles, a method can be mentioned in which the particle size of polytetrafluoroethylene particles is measured using a particle size distribution measuring device ("LS13 320" manufactured by Beckman Coulter) and the average value is calculated. The particle size of the polytetrafluoroethylene particles can also be measured by observing the cross section of the resin particle.

[0089] From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles is preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less. The lower limit of the coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles is not particularly limited. The coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles may be 0% or more or 1% or more. The range of the coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles can be set by appropriately selecting the lower limit and the upper limit.

[0090] The coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles can be measured as follows.

[0091] CV value (%) of the particle size of the polytetrafluoroethylene particles = (ρ / Dn) × 100, where ρ is the standard deviation of the particle size of the polytetrafluoroethylene particles. Dn: average particle size of the polytetrafluoroethylene particles

[0092] The shape of the polytetrafluoroethylene particles is not particularly limited, and may be spherical, or may be a shape other than spherical, such as flat.

[0093] It is preferable that the number of the polytetrafluoroethylene particles present in the region (R2) extending from the surface of the resin particle body to half the thickness toward the center be greater than the number of the polytetrafluoroethylene particles present in the region (R1) extending from the center of the resin particle body to half the thickness toward the surface. In this case, water repellency can be further improved and low dielectric properties can be more effectively exhibited. From the viewpoint of further improving water repellency and more effectively exhibiting low dielectric properties, it is preferable that the number of the polytetrafluoroethylene particles present on the surface of the resin particle body be greater than the number of the polytetrafluoroethylene particles present inside the resin particle body.

[0094] The number of polytetrafluoroethylene particles present in the region (R1) and the region (R2) can be measured, for example, as follows.

[0095] Resin particles were added to an epoxy resin so that the resin particle content was 30% by weight and dispersed to prepare a resin body for embedding resin particles for resin particle inspection. A cross-section of the resin particles was cut using a cross-section polisher (CP) (JEOL Ltd., "IB-09010CP") so as to pass through the center of the dispersed resin particles. Ten resin particles were then randomly selected and the polytetrafluoroethylene particles of each resin particle were observed using a FIB-SEM (FEI, "Helios Nanolab 650") at 10 kV and 200 pA. The number of polytetrafluoroethylene particles present in the region (R2) extending from the surface to half the thickness of the resin particle body toward the center and the region (R1) extending from the center to half the thickness of the resin particle body toward the surface were counted and averaged.

[0096] The ratio of the number of polytetrafluoroethylene particles present in the region (R2) to the number of polytetrafluoroethylene particles present in the region (R1) is defined as the ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)). The ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 3.0 or more, and particularly preferably 4.0 or more. When the ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) is equal to or greater than the lower limit, water repellency can be further increased and the dielectric loss tangent can be further reduced. The ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) may be 100 or less, 50 or less, or 10 or less. The range of the above ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) can be set by appropriately selecting the above lower limit and upper limit.

[0097] The content of the polytetrafluoroethylene particles in 100% by weight of the resin particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, even more preferably 1.0% by weight or more, particularly preferably 3.0% by weight or more, and is preferably 35% by weight or less, more preferably 30% by weight or less, even more preferably 20% by weight or less, particularly preferably 15% by weight or less, and most preferably 10% by weight or less. When the content of the polytetrafluoroethylene particles is above the lower limit and below the upper limit, water repellency can be further improved and low dielectric properties can be more effectively exhibited. When the content of the polytetrafluoroethylene particles is below the upper limit, the dispersibility of the resin particles in solvents can be further improved.

[0098] The content of the polytetrafluoroethylene particles relative to 100 parts by weight of the resin particle body is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, even more preferably 1.0 parts by weight or more, particularly preferably 3.0 parts by weight or more, and is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, even more preferably 20 parts by weight or less, particularly preferably 15 parts by weight or less, and most preferably 10 parts by weight or less. When the content of the polytetrafluoroethylene particles is above the lower limit, the water repellency can be further improved and the low dielectric property can be more effectively exhibited. When the content of the polytetrafluoroethylene particles is below the upper limit, the dispersibility of the resin particles in the solvent can be further improved.

[0099] <Other ingredients> The resin particles and the resin particle bodies may contain other components as necessary. Examples of the other components include dispersants, preservatives, polymerization inhibitors, polymerization initiators, colorants, and surfactants. The other components may be used alone or in combination of two or more.

[0100] The resin particles may or may not contain a surfactant, which may include anionic surfactants such as carboxylates, sulfonates, sulfates, and phosphates, cationic surfactants such as amine salts and ammonium salts, amphoteric surfactants, ester-type and ether-type nonionic surfactants, and fluorine-containing surfactants such as per(poly)fluoroalkyls.

[0101] From the viewpoint of reducing the environmental load, it is preferable that the resin particles contain a surfactant in an amount of 1 wt% or less, based on 100 wt% of the resin particles, or contain no surfactant. When the resin particles contain the surfactant, the content of the surfactant is preferably 0.5 wt% or less, more preferably 0.1 wt% or less, and even more preferably 0.01 wt% or less, based on 100 wt% of the resin particles. From the viewpoint of reducing the environmental load, it is more preferable that the resin particles do not contain a surfactant.

[0102] (Circuit board with insulating layer) The resin particles are preferably used to obtain a circuit board with an insulating layer. One example of the circuit board with an insulating layer includes a circuit board and an insulating layer disposed on the surface of the circuit board, the insulating layer containing the resin particles.

[0103] In the circuit board with an insulating layer, the insulating layer is preferably laminated on the surface of the circuit board on which the circuits are provided, and a portion of the insulating layer is preferably embedded between the circuits.

[0104] Specific examples of the circuit board with an insulating layer include a multilayer board and a multilayer printed wiring board.

[0105] An example of the multilayer substrate is a multilayer substrate including a circuit board and an insulating layer laminated on the circuit board. The insulating layer of the multilayer substrate contains the resin particles described above. The insulating layer is preferably laminated on the surface of the circuit board on which the circuits (metal layer) are provided. A portion of the insulating layer is preferably embedded between the circuits. The multilayer substrate preferably further includes a copper plating layer laminated on the surface of the insulating layer.

[0106] Another example of the multilayer substrate is a multilayer substrate comprising a circuit board, an insulating layer laminated on a surface of the circuit board, and copper foil laminated on the surface of the insulating layer opposite to the surface on which the circuit board is laminated.

[0107] Another example of the multilayer substrate is a multilayer substrate including a circuit board and a plurality of insulating layers laminated on a surface of the circuit board. At least one of the insulating layers disposed on the circuit board contains the resin particles. Preferably, the multilayer substrate further includes a circuit laminated on at least one surface of the insulating layer.

[0108] The multilayer printed wiring board includes, for example, a circuit board, a plurality of insulating layers disposed on a surface of the circuit board, and a metal layer disposed between the plurality of insulating layers, and at least one of the insulating layers contains the resin particles.

[0109] FIG. 3 is a cross-sectional view schematically showing a multilayer printed wiring board using resin particles according to the first embodiment of the present invention.

[0110] In the multilayer printed wiring board 11 (circuit board with insulating layers) shown in FIG. 3, a plurality of insulating layers 13-16 are stacked on an upper surface 12a of a circuit board 12. A metal layer 17 is formed in a partial region of the upper surface 12a of the circuit board 12. Of the plurality of insulating layers 13-16, insulating layers 13-15 other than insulating layer 16 located on the outer surface opposite the circuit board 12 side have a metal layer 17 formed in a partial region of the upper surface. The metal layer 17 is a circuit. A metal layer 17 is disposed between the circuit board 12 and insulating layer 13, and between each of the stacked insulating layers 13-16. The lower metal layer 17 and the upper metal layer 17 are connected to each other by at least one of via hole connection and through hole connection (not shown).

[0111] In the multilayer printed wiring board 11, the insulating layers 13 to 16 contain resin particles 1. Furthermore, in the multilayer printed wiring board 11, good insulating reliability is provided between the upper metal layer 17 and the lower metal layer 17 that are not connected by via hole connection or through hole connection (not shown). In this embodiment, all of the insulating layers 13 to 16 contain resin particles 1, but it is sufficient that at least one of the insulating layers 13 to 16 contains resin particles 1. Furthermore, resin particles such as resin particles 1A may be used instead of the resin particles 1. In FIG. 3, the resin particles 1 are shown in a schematic diagram.

[0112] The resin particles can also be used in copper-clad laminates. An example of the copper-clad laminate is a copper-clad laminate comprising a copper foil and an insulating layer laminated on one surface of the copper foil. The insulating layer of the copper-clad laminate contains the resin particles.

[0113] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0114] The following materials were prepared:

[0115] (material of the resin particle body) Styrene ("Styrene Monomer" manufactured by NS Styrene Monomer Co., Ltd.) Divinylbenzene (NS Styrene Monomer "DVB960") 2-(Perfluorohexyl)ethyl acrylate (Fujifilm Wako Pure Chemical Industries, Ltd.) Methyl methacrylate (Mitsubishi Chemical Corporation's "Acryester M") Ethylene glycol dimethacrylate ("Acryester ED" manufactured by Mitsubishi Chemical Corporation) N-Alkylbismaleimide compound (Designer Molecules Inc. "BMI-689")

[0116] Polytetrafluoroethylene particles (Kitamura "KTL-500F", average particle diameter 300 nm)

[0117] Example 1 50 parts by weight of divinylbenzene and 0.01 parts by weight of polytetrafluoroethylene particles were added to 49.99 parts by weight of styrene and stirred to obtain a monomer solution containing a dispersion of polytetrafluoroethylene particles. Next, 1 part by weight of a radical polymerization initiator (tert-butyl-2-ethylperoxyhexanoate, NOF Corporation's "Perbutyl O") was added to the resulting monomer solution and stirred until uniform, obtaining a monomer mixture. 200 parts by weight of a 1.0 wt% aqueous solution of polyvinyl alcohol with a molecular weight of approximately 2000 dissolved in pure water was placed in a reactor. The resulting monomer mixture was added to the aqueous solution in the reactor and stirred until the monomer droplets reached the desired particle size. The mixture was then heated at 90°C for 9 hours to polymerize the monomer droplets, yielding particles. The resulting particles were washed three times with hot water and acetone, and then classified to recover the resin particles. In the obtained resin particles, in at least one polytetrafluoroethylene particle, a portion of the polytetrafluoroethylene particle was present inside the resin particle body, and a portion of the polytetrafluoroethylene particle was present (exposed) on the surface (outside) of the resin particle body.

[0118] (Example 2 5 ,8 ,10~11,13 ~16 , and Reference Examples 6, 9, and 12 ) Resin particles were prepared in the same manner as in Example 1, except that the type and content (wt %) of the material of the resin particle body and the content (wt %) of polytetrafluoroethylene particles were changed as shown in Tables 1 to 4.

[0119] Example 7 Resin particles were prepared in the same manner as in Example 1, except that the material of the resin particle body and the content (wt%) of polytetrafluoroethylene particles were changed as shown in Table 2, and the concentration of polyvinyl alcohol was changed from a 1.0 wt% aqueous solution to a 5.0 wt% aqueous solution. In the obtained resin particles, all of the polytetrafluoroethylene particles were present inside the resin particle body.

[0120] (Comparative Example 1) No material for the resin particle body was used, and polytetrafluoroethylene particles were used as the resin particles.

[0121] (Comparative Example 2) 5 parts by weight of methyl methacrylate (25% by weight of 100% of the ingredients), 5 parts by weight of ethylene glycol dimethacrylate (25% by weight of 100% of the ingredients), and 0.1 parts by weight of a radical polymerization initiator (tert-butyl peroxypivalate, NOF Corporation's "Perbutyl PV") were dissolved in 89.9 parts by weight of acetone to obtain 100 parts by weight of an acetone solution. 10 parts by weight of polytetrafluoroethylene particles (50% by weight of 100% of the ingredients) were added to the resulting acetone solution and ultrasonically stirred at 50°C for 2 hours. The mixture was then filtered through a 10 μm mesh filter, washed with methanol, and dried to obtain coated resin particles in which the surfaces of polytetrafluoroethylene particles were coated with an acrylic polymer.

[0122] (Comparative Examples 3 and 4) Resin particles were prepared in the same manner as in Example 1, except that the type and content of the material of the resin particle body was changed as shown in Table 4 and polytetrafluoroethylene particles were not used.

[0123] (Comparative Example 5) Preparation of fluorine-containing acrylic particles A: Composition A containing 40 parts by weight of styrene, 50 parts by weight of divinylbenzene, 10 parts by weight of 2-(perfluorohexyl)ethyl acrylate, and 0.1 parts by weight of potassium persulfate was prepared in a 1000 mL separable flask equipped with a four-neck separable cover, stirring blade, three-way stopcock, condenser, and temperature probe. 900 parts by weight of distilled water was added to Composition A, and the mixture was stirred at 200 rpm and polymerized at 60°C for 24 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was freeze-dried to obtain fluorine-containing acrylic particles A.

[0124] Preparation of resin particles: Resin particles were obtained in the same manner as in Example 1, except that the type and content of the material of the resin particle body were changed as shown in Table 5, and that the obtained fluorine-containing acrylic particles A were used in the content shown in Table 5 instead of the polytetrafluoroethylene particles.

[0125] (Comparative Example 6) Resin particle bodies were obtained in the same manner as in Example 1, except that polytetrafluoroethylene particles were not used and the type and content of the material of the resin particle body were changed as shown in Table 5. 10 parts by weight of the fluorine-containing acrylic particles A obtained in Comparative Example 5 and 90 parts by weight of the obtained resin particle body were dispersed in acetone and subjected to ultrasonic stirring at 50°C for 30 minutes. The dispersion was then washed with methanol and dried to obtain resin particles with fluorine-containing acrylic particles A fixed to the surface.

[0126] (Comparative Example 7) Resin particles were obtained in the same manner as in Example 1, except that the type and content of the material of the resin particle body were changed as shown in Table 5, and that the fluorine-containing acrylic particles A obtained in Comparative Example 5 were used in the content shown in Table 5 instead of the polytetrafluoroethylene particles.

[0127] (Comparative Example 8) Resin particle bodies were obtained in the same manner as in Example 1, except that polytetrafluoroethylene particles were not used and the type and content of the material of the resin particle body were changed as shown in Table 5. 10 parts by weight of the fluorine-containing acrylic particles A obtained in Comparative Example 5 and 90 parts by weight of the obtained resin particle body were dispersed in acetone and subjected to ultrasonic stirring at 50°C for 30 minutes. The dispersion was then washed with methanol and dried to obtain resin particles with fluorine-containing acrylic particles A fixed to the surface.

[0128] (evaluation) (1) Average particle size The particle sizes of approximately 100,000 of the obtained resin particles were measured using a particle size distribution measuring device (Multisizer 4 manufactured by Beckman Coulter) to determine the average particle size.

[0129] (2) CV value of particle size The CV value of the particle diameter of the obtained resin particles was calculated by the method described above.

[0130] (3) Aspect ratio The aspect ratio of the obtained resin particles was calculated by the method described above.

[0131] (4) Specific gravity The specific gravity of the resulting resin particles was calculated by the method described above.

[0132] (5) Dielectric constant The dielectric constant of the obtained resin particles at 1 GHz was calculated using a dielectric constant measuring device (manufactured by AET, using a powder measurement resonator).

[0133] (6) Dielectric tangent The dielectric loss tangent at 1 GHz of the obtained resin particles was calculated using a dielectric constant measuring device (manufactured by AET, using a powder measurement resonator).

[0134] (7) Ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) For the obtained resin particles, the number of polytetrafluoroethylene particles present in the region (R2) extending from the surface of the resin particle body toward the center to half the thickness of the resin particle body, and the number of polytetrafluoroethylene particles present in the region (R1) extending from the center of the resin particle body toward the surface to half the thickness of the resin particle body, were counted in the cross section of the resin particle using the method described above. Next, the ratio (number of polytetrafluoroethylene particles present in region (R2) / number of polytetrafluoroethylene particles present in region (R1)) was calculated. In Comparative Examples 5 and 7, the ratio (number of fluorine-containing acrylic particles A present in region (R2) / number of fluorine-containing acrylic particles A present in region (R1)) was calculated.

[0135] (8) Dispersibility of resin particles in solvent (presence or absence of aggregation) Water, acetone, and epoxy resin (bisphenol A epoxy resin, "jER" manufactured by Mitsubishi Chemical Corporation) were prepared as solvents. 1 part by weight of the obtained resin particles was dispersed in 100 parts by weight of each solvent, and the average particle diameter of the resin particles dispersed in each solvent was measured using an optical microscope ("VH-Z450" manufactured by Keyence Corporation) to observe whether or not the resin particles had aggregated. Aggregation was determined to have occurred when the average particle diameter of the resin particles dispersed in each solvent was at least twice the average particle diameter of the resin particles. The overall evaluation of the dispersibility of the resin particles in each solvent (presence or absence of aggregation) was determined according to the following criteria.

[0136] [Criteria for determining the dispersibility of resin particles in solvents (overall evaluation)] ○: Resin particles do not aggregate in all solvents ×: Resin particles aggregate in at least one solvent

[0137] (9) Inkjet ejection properties Composition A was obtained by dispersing 10 parts by weight of the resulting resin particles in a mixture of 50 parts by weight of epoxy resin (bisphenol A-type epoxy resin, "jER" manufactured by Mitsubishi Chemical Corporation) and 50 parts by weight of glycidyl ether. Composition A was ejected onto a substrate from the inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device. When printing with the inkjet printer, whether composition A could be ejected was evaluated visually, and the ejectability was judged according to the following criteria. Note that when ejecting compositions A with a viscosity of 500 mPa·s or less, the head temperature was set to 80°C, and when ejecting compositions A with a viscosity exceeding 500 mPa·s, the head temperature was set to 95°C.

[0138] [Inkjet ejection performance evaluation criteria] ○○○: Composition A could be continuously discharged from the head for more than one hour. XX: Composition A can be continuously discharged from the head for more than one hour, but slight unevenness in discharge occurs during one hour of continuous discharge. ○: Composition A could be continuously discharged from the head, but it was impossible to continuously discharge it for more than one hour. ×: Composition A could not be ejected from the head in the initial stage.

[0139] (10) Low dielectric constant of the film Composition B was obtained by dispersing 10 parts by weight of the obtained resin particles in a mixture of 50 parts by weight of epoxy resin (bisphenol A type epoxy resin, "jER" manufactured by Mitsubishi Chemical Corporation), 50 parts by weight of glycidyl ether, and 1 part by weight of SI-60L (manufactured by Sanshin Chemical Industry Co., Ltd.). Composition B obtained was applied to a substrate to a thickness of 100 μm and heated at 100°C for 2 hours to obtain a film. The dielectric loss tangent of the obtained film was measured using a dielectric constant measuring device (manufactured by AET, using a cavity resonator). The low dielectric properties of the film were evaluated according to the following criteria.

[0140] [Criteria for determining low dielectric properties of film] ○○○: Dielectric tangent is less than 0.003 ○○: Dielectric tangent is 0.003 or more and less than 0.006 ○: Dielectric tangent is 0.006 or more and less than 0.010 ×: Dielectric tangent is 0.010 or more

[0141] (11) Water repellency of the film For the obtained film, 1 ml of water was dropped onto the film, and the contact angle of the water with the film was measured. The water repellency of the film was evaluated according to the following criteria.

[0142] [Criteria for determining film water repellency] ○○○: Contact angle is 130° or more ○○: Contact angle is 110° or more and less than 130° ○: Contact angle is 90° or more and less than 110° ×: Contact angle less than 90°

[0143] The composition of the resin particles and the results are shown in Tables 1 to 5 below.

[0144] [Table 1]

[0145] [Table 2]

[0146] [Table 3]

[0147] [Table 4]

[0148] [Table 5]

[0149] As shown in Tables 4 and 5, the following results can be seen. Comparative Example 1, which did not contain resin particle bodies and contained only polytetrafluoroethylene particles (PTFE particles), was inferior in dispersibility of the resin particles in a solvent and in inkjet ejection properties. Furthermore, Comparative Example 2, in which the surfaces of the polytetrafluoroethylene particles were coated with an acrylic polymer, was inferior in dispersibility of the resin particles in a solvent, inkjet ejection properties, and film water repellency. Comparative Examples 3 and 4, which did not contain polytetrafluoroethylene particles, were inferior in low dielectric constant and water repellency of the film. Furthermore, Comparative Examples 5 to 8, which did not use polytetrafluoroethylene particles but used fluorine-containing acrylic particles A, were inferior in low dielectric constant and water repellency of the film. [Explanation of symbols]

[0150] 1,1A...Resin particles 2...Resin particle body 3,3A...Polytetrafluoroethylene particles 11...Multilayer printed wiring board (circuit board with insulating layer) 12...Circuit board 12a…Top surface 13~16...Insulating layer 17...Metal layer

Claims

1. The resin particles include a resin particle body and a plurality of polytetrafluoroethylene particles, a plurality of the polytetrafluoroethylene particles are present either on the surface of the resin particle body or in the interior of the resin particle body, or both on the surface of the resin particle body and in the interior of the resin particle body; the resin particle body is a polymer of a polymerizable component, the polymerizable component contains a polymerizable compound having one or more ethylenically unsaturated groups, the number average particle diameter of the resin particles is 50 μm or less, and the number average particle diameter of the resin particles is measured using a particle size distribution measuring device; the CV value of the particle diameter of the resin particles is 20% or less, The resin particles have a content of the polytetrafluoroethylene particles of 25% by weight or less based on 100% by weight of the resin particles.

2. 2. The resin particles according to claim 1, wherein the number average particle diameter of the polytetrafluoroethylene particles is 10 nm or more and 500 nm or less, and the number average particle diameter of the polytetrafluoroethylene particles is measured using a particle size distribution measuring device.

3. The resin particles according to claim 1 or 2, wherein the number average particle diameter of the resin particles is 0.5 μm or more and 50 μm or less.

4. The resin particles according to claim 1 or 2, wherein the resin particles have an aspect ratio of 1.5 or less.

5. The resin particles according to claim 1 or 2, wherein the specific gravity of the resin particles is 1.6 or less.

6. 3. The resin particles according to claim 1, wherein the content of the polytetrafluoroethylene particles is 0.01% by weight or more and 25% by weight or less based on 100% by weight of the resin particles.

7. The resin particles according to claim 1 or 2, wherein the resin particles have a dielectric constant of 2.60 F / m or less.

8. The resin particles according to claim 1 or 2, wherein the resin particles have a dielectric loss tangent of less than 0.

010.

9. A resin particle as described in claim 1 or 2, wherein in at least one of the multiple polytetrafluoroethylene particles, a portion of the polytetrafluoroethylene particle is present inside the resin particle body and a portion of the polytetrafluoroethylene particle is present on the surface of the resin particle body.

10. Resin particles as described in claim 1 or 2, wherein the number of polytetrafluoroethylene particles present in the region from the surface of the resin particle body to 1 / 2 of the thickness toward the center is greater than the number of polytetrafluoroethylene particles present in the region from the center of the resin particle body to 1 / 2 of the thickness toward the surface.

11. A circuit board; an insulating layer disposed on a surface of the circuit board; A circuit board with an insulating layer, wherein the insulating layer contains the resin particles according to claim 1 or 2.

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