TW202446814A - Resin particles and circuit substrate with insulating layer - Google Patents

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

Resin particles and circuit substrate with insulating layer

The present invention relates to a resin particle containing polytetrafluoroethylene particles and a circuit substrate with an insulating layer using the resin particle.

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

On the other hand, since most of the particles containing fluorine resins are easy to aggregate and have a large specific gravity, they have the property of being difficult to disperse in a solvent. Therefore, there is a problem that it is difficult to evenly disperse the particles containing fluorine resins in a solvent for processing.

In addition, a large amount of surfactant is sometimes used to disperse the particles containing fluorine-based resin in the solvent. However, the addition of a large amount of surfactant has the problem of a large environmental load.

The following patent document 1 discloses a composite particle (C) comprising: a particle (F) comprising a fluorine-containing polymer (A); and a polymer (B) having a monomer (b) as a structural monomer. Regarding the composite particle (C), the surface of the particle (F) is coated with a coating layer containing the polymer (B). The composite particle (C) has an impregnation layer in which the polymer (B) is impregnated from the surface of the particle (F) to the inside. In patent document 1, examples of the polymer (B) include vinyl resins, epoxy resins, and polyurethane resins. [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent Publication No. 2016-121352

[The problem the invention is trying to solve]

In the composite particles formed by coating fluorine-containing particles with urethane resins, as described in Patent Document 1, the excellent water repellency and low dielectric properties of the fluorine-based resins cannot be fully exerted because the fluorine-based resins are coated with polymers. In addition, in the previous composite particles described in Patent Document 1, the composite particles sometimes form unintended aggregates due to stimulation such as stirring, heating, or reaction during the formation of the composite particles. As a result, the dispersibility of the composite particles in the solvent cannot be fully improved.

That is, in the conventional composite particles including fluorine-based resins, it is difficult to improve the dispersibility in a solvent, improve the water repellency, and exert low dielectric properties.

The purpose of the present invention is to provide a resin particle that can improve dispersibility in a solvent, improve water repellency, and exert low dielectric properties, and a circuit substrate with an insulating layer using the resin particle. [Technical means to solve the problem]

This specification discloses the following resin particles and a circuit substrate with an insulating layer.

Item 1. A resin particle comprising a resin particle body and a plurality of polytetrafluoroethylene particles, wherein the plurality of polytetrafluoroethylene particles are present only on one of the surface of the resin particle body and the interior of the resin particle body, or on both the surface of the resin particle body and the interior of the resin particle body, and the resin particle body is a polymer of a polymerizable component, and the polymerizable component comprises a polymerizable compound having one or more ethylenically unsaturated groups.

Item 2. The resin particles as described in Item 1, wherein the particle size of the polytetrafluoroethylene particles is not less than 10 nm and not more than 500 nm.

Item 3. The resin particles according to Item 1 or 2, wherein the particle size of the resin particles is greater than 0.5 μm.

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

Item 5. The resin particle according to any one of Items 1 to 4, wherein the aspect ratio of the resin particle is 1.5 or less.

Item 6. The resin particle as described in any one of Items 1 to 5, wherein the specific gravity of the resin particle is 1.6 or less.

Item 7. The resin particles as described in any one of Items 1 to 6, wherein the content of the polytetrafluoroethylene particles in 100 wt % of the resin particles is 0.01 wt % to 35 wt %.

Item 8. The resin particle as described in any one of Items 1 to 7, wherein the dielectric constant of the resin particle is less than 2.60 F/m.

Item 9. The resin particle as described in any one of Items 1 to 8, wherein the dielectric dissipation factor of the resin particle is less than 0.010.

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

Item 11. The resin particle as described in any one of Items 1 to 10, wherein the number of the above-mentioned polytetrafluoroethylene particles existing in the region from the surface of the above-mentioned resin particle body toward the center to 1/2 of the thickness is greater than the number of the above-mentioned polytetrafluoroethylene particles existing in the region from the center of the above-mentioned resin particle body toward the surface to 1/2 of the thickness.

Item 12. A circuit substrate with an insulating layer, comprising: a circuit substrate; and an insulating layer disposed on the surface of the circuit substrate; and the insulating layer comprises resin particles as described in any one of items 1 to 11. [Effect of the invention]

The resin particles of the present invention include a resin particle body and a plurality of polytetrafluoroethylene particles. In the resin particles of the present invention, the plurality of polytetrafluoroethylene particles exist only on one of the surface of the resin particle body and the interior of the resin particle body, or exist on both the surface of the resin particle body and the interior of the resin particle body. In the resin particles of the present invention, the resin particle body is a polymer of a polymerizable component, and the polymerizable component includes a polymerizable compound having one or more ethylenically unsaturated groups. In the resin particles of the present invention, due to the above-mentioned structure, the dispersibility in the solvent can be improved, the water repellency can be improved, and the low dielectric property can be exhibited.

Hereinafter, the present invention will be described in detail. In the present specification, for example, "(meth)acryloxy" means one or both of "acryloxy" and "methacryloxy", and "(meth)acrylic acid" means one or both of "acrylic acid" and "methacrylic acid".

(Resin particles) The resin particles of the present invention include a resin particle body and a plurality of polytetrafluoroethylene particles. In the resin particles of the present invention, the plurality of polytetrafluoroethylene particles exist only on the surface of the resin particle body and in the interior of the resin particle body, or exist on both the surface of the resin particle body and in the interior of the resin particle body. In the resin particles of the present invention, the resin particle body is a polymer of a polymerizable component, and the polymerizable component includes a polymerizable compound having one or more ethylenically unsaturated groups.

The resin particles of the present invention have the above-mentioned structure, so the dispersibility in the solvent can be improved. As a result, when the resin particles of the present invention are dispersed in the solvent, the resin particles do not form unintentional aggregates, so the ink jetting property can be improved, and the molding stability when the composition containing the resin particles is molded can be improved. In addition, in the resin particles of the present invention, it is not necessary to add a large amount of surfactant in order to disperse in the solvent, so the environmental load can be reduced, and the exudation due to the surfactant can be suppressed, and the resin particles can be suppressed from peeling off from the molded body of the composition containing the resin particles. Furthermore, the resin particles of the present invention have the above-mentioned structure, so the water repellency can be improved and the low dielectric property can be exhibited.

In the resin particles of the present invention, the plurality of polytetrafluoroethylene particles may be present on the surface (outside) of the resin particle body, may be present inside the resin particle body, or may be present on the surface (outside) and inside the resin particle body. Furthermore, in the resin particles of the present invention, the plurality of polytetrafluoroethylene particles may be present on at least the surface (outside) of the resin particle body, or may be present at least inside the resin particle body.

In the resin particles, any one of the polytetrafluoroethylene particles may be present in its entirety on the surface (outside) of the resin particle body, or a portion of any one of the polytetrafluoroethylene particles may be present (exposed) on the surface (outside) of the resin particle body. In the resin particles, any one of the polytetrafluoroethylene particles may be present in its entirety inside the resin particle body, or a portion of any 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 on the surface (outside) of the resin particle body, or a portion (at least one) of the polytetrafluoroethylene particles may be present on the surface (outside) of the resin particle body. In the resin particles, all of the polytetrafluoroethylene particles may be present on the surface (outside) of the resin particle body, or at least one of the polytetrafluoroethylene particles may be present on the surface (outside) 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.

The resin particles may include the following polytetrafluoroethylene particles: polytetrafluoroethylene particles on the surface (outside) of the resin particle body, polytetrafluoroethylene particles on the surface (outside) and inside (partially outside) the resin particle body, and polytetrafluoroethylene particles inside the resin particle body. From the viewpoint of further improving water repellency, it is preferred that, in at least one of the plurality of polytetrafluoroethylene particles, a portion of the polytetrafluoroethylene particles is inside the resin particle body, and a portion of the polytetrafluoroethylene particles is present (exposed) on the surface (outside) of the resin particle body. From the viewpoint of further improving water repellency, it is preferred that, in a portion (at least one) of the polytetrafluoroethylene particles, a portion of the polytetrafluoroethylene particles is present inside the resin particle body, and a portion of the polytetrafluoroethylene particles is present (exposed) on the surface (outside) of the resin particle body. In the resin particles, it is preferred that the following polytetrafluoroethylene particles exist, namely, 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 (a portion exists outside the resin particle body), and the polytetrafluoroethylene particles exist only inside the resin particle body. In such cases, water repellency can be further improved, and low dielectric properties can be more effectively exerted.

Hereinafter, the present invention will be described in detail with reference to the drawings.

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

The resin particle 1 shown in FIG1 includes a resin particle body 2 and a plurality of polytetrafluoroethylene particles 3. In the resin particle 1, all the polytetrafluoroethylene particles 3 are present on the surface (outside) and inside the resin particle body 2. In the resin particle 1, among all the polytetrafluoroethylene particles 3, a portion of the polytetrafluoroethylene particles 3 are present inside the resin particle body 2, and a portion of the polytetrafluoroethylene particles 3 are present on the surface (outside) of the resin particle body 2.

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

The 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 (outside) and inside 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 (outside) and inside the resin particle body 2. In the resin particle 1A, in at least one of the plurality of polytetrafluoroethylene particles 3A, a portion of the polytetrafluoroethylene particle 3A is present inside the resin particle body 2, and a portion of the polytetrafluoroethylene particle 3A is present on the surface (outside) of the resin particle body 2.

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

The dielectric constant of the above-mentioned resin particles is preferably below 2.60 F/m, more preferably below 2.50 F/m, further preferably below 2.40 F/m, particularly preferably below 2.35 F/m, and most preferably below 2.30 F/m. When the dielectric constant of the above-mentioned resin particles is below the above-mentioned upper limit, the low dielectric property can be further effectively exerted. The lower limit of the dielectric constant of the above-mentioned resin particles is not particularly limited. The dielectric constant of the above-mentioned resin particles can be above 1.80 F/m, and can also be above 1.90 F/m. Regarding the range of the dielectric constant of the above-mentioned resin particles, the above-mentioned lower limit value and the above-mentioned upper limit value can be appropriately selected and set.

The dielectric loss tangent of the above-mentioned resin particles is preferably below 0.010, preferably below 0.010, more preferably below 0.006, more preferably below 0.006, further preferably below 0.005, particularly preferably below 0.003, particularly preferably below 0.003, and most preferably below 0.001. When the dielectric loss tangent of the above-mentioned resin particles is (does not reach) below the above-mentioned upper limit, the low dielectric property can be further effectively exerted. The lower limit of the dielectric loss tangent of the above-mentioned resin particles is not particularly limited. The dielectric loss tangent of the above-mentioned resin particles can be above 0.0001, and can also be above 0.0005. Regarding the range of the dielectric dissipation factor of the resin particles, the lower limit value and the upper limit value may be appropriately selected and set.

The dielectric constant and dielectric dissipation factor of the resin particles can be measured, for example, as follows. The resin particles are filled into a quartz tube and placed in a resonator for powder measurement. The dielectric constant and dielectric dissipation factor of the resin particles are measured at 1 GHz using a dielectric constant measuring device (manufactured by AET Corporation).

The 10% K value of the resin particles at 25° C. is preferably 100 N/mm ² or more, more preferably 500 N/mm ² or more, further preferably 1000 N/mm ² or more, and preferably 20000 N/mm ² or less, more preferably 15000 N/mm ² or less, further preferably 10000 N/mm ² or less, and particularly preferably 8000 N/mm ² or less. When the 10% K value of the resin particles at 25° C. is above the lower limit and below the upper limit, interfacial peeling of the polytetrafluoroethylene particles and the resin particle body can be suppressed.

The 10%K value of the above-mentioned resin particles at 25°C can be measured as follows. Using a micro-compression tester, utilize the smooth pressure head end face of a cylinder (diameter 50 μm, made of diamond) to compress the resin particles at 25°C for 60 seconds under the condition of a maximum test load of 20 mN. Measure the load value (N) and the compression displacement (mm) at this time. Based on the obtained measured values, the 10%K value of the above-mentioned resin particles at 25°C can be calculated according to the following formula. As the above-mentioned micro-compression tester, for example, the "Fischerscope H-100" manufactured by Fischer Company can be used.

10% K value (N/mm ² ) = (3/2 ^1/2 )·F·S ^-3/2 ·R ^-1/2 F: Load value when the resin particle is compressed and deformed by 10% (N) S: Compression displacement when the resin particle is compressed and deformed by 10% (mm) R: Radius of the resin particle (mm)

From the viewpoint of suppressing the shrinkage of the resin particles when the composition containing the resin particles is formed, the compression recovery rate of the resin particles at 25° C. is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, and is preferably 95% or less, more preferably 90% or less, further preferably 80% or less. The compression recovery rate of the resin particles at 25° C. may be 70% or less.

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

Spread the resin particles on the specimen stage. For one of the scattered resin particles, use a micro-compression tester, and use the smooth indentation end surface of a cylinder (diameter 50 μm, made of diamond) to apply a load of 1.0 mN and a reverse load of 10 mN at the origin along the center direction of the resin particle at 25°C, and analyze the recovery behavior after the load is removed to derive the compression recovery rate. The load-compression displacement during this period can be measured, and the compression recovery rate can be calculated according to the following formula. In addition, the load speed is set to 0.33 m N/sec. As the above-mentioned micro-compression tester, for example, the "Fischerscope H-100" manufactured by Fischer Company can be used.

Compression recovery rate (%) = [L2/L1] × 100 L1: Compression displacement from the load value at the origin when the load is applied to the reversal load value L2: Unloading displacement from the reversal load value when the load is released to the load value at the origin

The particle size of the resin particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, further preferably 3.0 μm or more, particularly preferably 5.0 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, further preferably 30 μm or less, further 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 above the lower limit and below the upper limit, the dispersibility of the resin particles in the solvent can be further improved.

The particle diameter of the resin particle indicates the diameter when the resin particle is a true sphere, and indicates the diameter when the resin particle is a shape other than a true sphere, assuming a true sphere of the same volume.

The particle size of the above-mentioned resin particles is preferably an average particle size, and more preferably a number average particle size. The particle size of the above-mentioned resin particles can be measured by any particle size distribution measuring device. For example, it can be measured using a particle size distribution measuring device that utilizes the principles of laser light scattering, resistance value change, image analysis after shooting, etc. More specifically, as a method for measuring the particle size of the resin particles, the following method can be cited, that is, using a particle size distribution measuring device ("Multisizer4" manufactured by Beckman Coulter), the particle size of approximately 100,000 resin particles is measured, and the average value is calculated.

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 resin particles is preferably 35% or less, more preferably 30% or less, further preferably 25% or less, further 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 size of the resin particles is not particularly limited. The coefficient of variation (CV value) of the particle size of the resin particles may be 0% or more, or 1% or more. With respect to the range of the coefficient of variation (CV value) of the particle size of the resin particles, the lower limit and the upper limit may be appropriately selected and set.

The coefficient of variation (CV value) of the particle size of the resin particles can be measured as follows.

CV value of the particle size of the above resin particles (%) = (ρ/Dn) × 100 ρ: standard deviation of the particle size of the above resin particles Dn: average value of the particle size of the above resin particles

The shape of the resin particles is not particularly limited. The resin particles may be spherical, other than spherical, or flat. From the perspective of further improving the dispersibility of the resin particles in the solvent, the resin particles are preferably spherical.

From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the aspect ratio of the above-mentioned resin particles is preferably less than 1.5, more preferably less than 1.4, further preferably less than 1.3, particularly preferably less than 1.2, and most preferably less than 1.1. The lower limit of the aspect ratio of the above-mentioned resin particles is not particularly limited. The aspect ratio of the above-mentioned resin particles may be greater than 1.0, and may also be greater than 1.1. From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the aspect ratio of the above-mentioned resin particles is preferably 1.0. Regarding the range of the aspect ratio of the above-mentioned resin particles, the above-mentioned lower limit value and the above-mentioned upper limit value may be appropriately selected and set.

The aspect ratio represents the major diameter/minor diameter. The aspect ratio is preferably obtained by observing any 10 resin particles using an electron microscope or an optical microscope, setting the maximum diameter and the minimum diameter as the major diameter and the minor diameter, respectively, and calculating the average value of the major diameter/minor diameter of each spherical resin particle.

From the viewpoint of preventing the resin particles from precipitating in the solvent and further improving 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, further 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 lower limit and the upper limit may be appropriately selected and set in the range of the specific gravity of the resin particles.

The resin particles are preferably used by being dispersed in a solvent. The resin particles are preferably used by being dispersed in a solvent in the form of a composition. The solvent for dispersing the resin particles may be aqueous or oily. Examples of the solvent for dispersing the resin particles include: silicone, water, mineral oil, polyether derivatives; alcohols such as methanol, ethanol, isopropyl alcohol, and fluorinated 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, pyruvate, 2-hydroxyisobutyric acid, and lactate; amides such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as octane and decane; and resins. Examples of the resin include rubber, vinyl resin, acrylic resin, urethane resin, melamine resin, polyester resin, polyol resin, engineering plastic, silicone resin, fluororesin, and epoxy resin. When the resin particles are dispersed in a solvent and used in a liquid state, the solvent is preferably silicone, water, mineral oil, polyether derivative, etc. The composition in which the resin particles are dispersed in the solvent is particularly preferably used in lubricants and non-adhesives. When the resin particles are dispersed in a solvent and then the solvent is vaporized for use, the solvent is preferably 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, pyruvate, 2-hydroxyisobutyric acid, and lactate; amides such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as octane and decane; and water. The composition in which the resin particles are dispersed in the solvents is particularly preferably used in inks, coating agents, paints, and photoreceptors. The composition in which the resin particles are dispersed in the resin is particularly preferably used in coating agents, paints, non-stickiness agents, and anti-drip agents.

The composition comprising the above-mentioned resin particles and solvent can be applied using an inkjet device, can be applied by screen printing, or can be applied by dispensing. Generally speaking, since the previous composite particles comprising fluorine-based resins are easily precipitated when dispersed in a solvent, it is sometimes difficult to improve the inkjet ejection property. On the other hand, since the above-mentioned resin particles have the above-mentioned structure, the inkjet ejection property can be improved when the above-mentioned resin particles are dispersed in a solvent.

From the viewpoint of further improving 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, further preferably 0.8 or more, and is preferably 1.5 or less, more preferably 1.4 or less, further preferably 1.3 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less.

From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the resin particles are preferably dispersed in toluene or epoxy resin for use.

Hereinafter, each component of the resin particle will be described in detail.

<Resin particle body> The resin particles have a resin particle body. The resin particles and the resin particle body contain 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 is preferably a polymer containing a polymerizable compound having one or more ethylenically unsaturated groups. The resin particle body is preferably a polymer containing a polymerizable compound having two or more ethylenically unsaturated groups.

As the above-mentioned polymerizable compound (monomer) having one or more ethylenically unsaturated groups, there can be exemplified a polymerizable compound having one ethylenically unsaturated group and a polymerizable compound having two or more ethylenically unsaturated groups. The above-mentioned polymerizable compound having two or more ethylenically unsaturated groups may have 100 or less ethylenically unsaturated groups, or may have 10 or less. Only one of the above-mentioned polymerizable compounds having one or more ethylenically unsaturated groups may be used, or two or more of them may be used in combination. Only one of the above-mentioned polymerizable compounds having one ethylenically unsaturated group may be used, or two or more of them may be used in combination. Only one of the above-mentioned polymerizable compounds having two or more ethylenically unsaturated groups may be used, or two or more of them may be used in combination.

Examples of the polymerizable compound (monomer) having one or more ethylenically unsaturated groups include non-crosslinking monomers and crosslinking monomers. The polymerizable compound (monomer) having one or more ethylenically unsaturated groups may be a polymerizable compound having one or more maleimide groups.

Examples of the non-crosslinking monomers include: styrene monomers such as styrene and α-methylstyrene; carboxyl 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 isobutyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, glyceryl (meth)acrylate, and polyisobutylene esters; Oxyethylene (meth)acrylate, glycidyl (meth)acrylate and other oxygen-containing (meth)acrylate monomers; (meth)acrylonitrile and other nitrile-containing monomers; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether and other vinyl ethers; vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate and other acid vinyl esters; ethylene, propylene, isoprene, butadiene and other unsaturated hydrocarbons; trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, (perfluorohexyl)ethyl (meth)acrylate, vinyl chloride, vinyl fluoride, chlorostyrene and other halogen-containing monomers; polymerizable compounds having one maleimide group, etc.

Examples of the crosslinking monomer include tetrahydroxymethylmethane tetra(meth)acrylate, tetrahydroxymethylmethane tri(meth)acrylate, tetrahydroxymethylmethane di(meth)acrylate, trihydroxymethylpropane 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, (poly)propylene glycol di(meth)acrylate, ( Polyfunctional (meth)acrylates such as poly((meth))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, trimethoxysilyl styrene, and vinyltrimethoxysilane; polymerizable compounds having two or more maleimide groups, etc. The above-mentioned polymerizable compound having two or more maleimide groups may be a polymerizable compound having two maleimide groups, or may be a dimaleimide compound. The polymerizable compound having two or more maleimide groups may have 100 or less maleimide groups, or 10 or less maleimide groups.

The above-mentioned polymerizable compound (polymerizable component) having one or more ethylenic 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 effect of the present invention can be effectively exerted. From the viewpoint of further effectively exerting the effect of the present invention, the above-mentioned polymerizable compound (polymerizable component) having one or more ethylenic unsaturated groups preferably includes styrene, divinylbenzene, methyl (meth)acrylate, or (poly)ethylene glycol di(meth)acrylate, and further preferably includes styrene or divinylbenzene. From the viewpoint of further effectively exerting the effect of the present invention, the above-mentioned polymerizable compound (polymerizable component) having one or more ethylenic unsaturated groups preferably includes styrene and divinylbenzene. In such cases, the dispersibility of the 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 property of the resin particles can be further effectively exerted.

From the viewpoint of improving solvent resistance and chemical resistance, the resin particle body preferably comprises a copolymer of styrene and divinylbenzene.

The resin particle body can be obtained by polymerizing the polymerizable compound having one or more ethylenically unsaturated groups by a known method. Examples of such methods include a method of performing suspension polymerization in the presence of a radical polymerization initiator, and a method of performing polymerization by swelling the polymerizable compound and the radical polymerization initiator using non-crosslinked seed particles.

The particle size of the resin particle body is preferably 0.5 μm or more, more preferably 1.0 μm or more, further preferably 3.0 μm or more, particularly preferably 5.0 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, further preferably 30 μm or less, further 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 particle body is above the lower limit and below the upper limit, the dispersibility and water repellency of the resin particle in the solvent can be further improved.

The particle diameter of the resin particle body refers to the diameter when the resin particle body is a true sphere, and refers to the diameter when the resin particle body is a shape other than a true sphere, assuming a true sphere of the same volume.

The particle size of the resin particle body is preferably an average particle size, and more preferably a number average particle size. The particle size of the resin particle body can be measured by any particle size distribution measuring device. For example, a particle size distribution measuring device that utilizes the principles of laser light scattering, resistance value change, image analysis after shooting, etc. can be used for measurement. More specifically, as a method for measuring the particle size of the resin particle body, the following method can be cited, that is, using a particle size distribution measuring device ("Multisizer4" manufactured by Beckman Coulter), the particle size of approximately 100,000 resin particles is measured, and the average particle size is calculated.

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 resin particle body is preferably 35% or less, more preferably 30% or less, further preferably 25% or less, further 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 size of the resin particle body is not particularly limited. The coefficient of variation (CV value) of the particle size of the resin particle body may be 0% or more, or 1% or more. With respect to the range of the coefficient of variation (CV value) of the particle size of the resin particle body, the lower limit value and the upper limit value may be appropriately selected and set.

The coefficient of variation (CV value) of the particle size of the resin particles can be measured as follows.

CV value of the particle size of the resin particle body (%) = (ρ/Dn) × 100 ρ: standard deviation of the particle size of the resin particle body Dn: average value of the particle size of the resin particle body

The shape of the resin particle body is not particularly limited. The shape of the resin particle body may be spherical, other than spherical, or flat.

In the above-mentioned resin particles 100 weight %, the content of the above-mentioned resin particle body is preferably 60 weight % or more, more preferably 70 weight % or more, further preferably 80 weight % or more, particularly preferably 90 weight % or more, and most preferably 95 weight % or more, and preferably 99.99 weight % or less, more preferably 99.9 weight % or less, further preferably 99 weight % or less, and particularly preferably 98 weight % or less. When the content of the above-mentioned resin particle body is above the above lower limit and below the above upper limit, the dispersibility of the resin particles in the solvent can be further improved. In the above-mentioned resin particles 100 weight %, the content of the above-mentioned resin particle body can be below 95 weight % or below 90 weight %.

In 100 wt % of the above-mentioned polymerizable components, the content of the above-mentioned polymerizable compound having one or more ethylenically unsaturated groups is preferably 80 wt % or more, more preferably 85 wt % or more, further preferably 90 wt % or more, and particularly preferably 95 wt % or more. When the content of the above-mentioned polymerizable compound having one or more ethylenically unsaturated groups is above the above-mentioned lower limit, the solvent resistance and chemical resistance can be improved. The upper limit of the content of the above-mentioned polymerizable compound having one or more ethylenically unsaturated groups is not particularly limited. In 100 wt % of the above-mentioned polymerizable components, the content of the above-mentioned polymerizable compound having one or more ethylenically unsaturated groups may be 100 wt % (total amount) or may be less than 100 wt %. Regarding the range of the content of the polymerizable compound having one or more ethylenically unsaturated groups in 100% by weight of the polymerizable component, the lower limit and the upper limit can be appropriately selected and set.

In the above-mentioned polymerizable component 100 weight %, the content of the above-mentioned polymerizable compound having more than two ethylenically unsaturated groups is preferably 80 weight % or more, more preferably 85 weight % or more, further preferably 90 weight % or more, and particularly preferably 95 weight % or more. When the content of the above-mentioned polymerizable compound having more than two ethylenically unsaturated groups is more than the above-mentioned lower limit, the solvent resistance and chemical resistance can be improved. The upper limit of the content of the above-mentioned polymerizable compound having more than two ethylenically unsaturated groups is not particularly limited. In the above-mentioned polymerizable component 100 weight %, the content of the above-mentioned polymerizable compound having more than two ethylenically unsaturated groups may be 100 weight % (total amount) or may be less than 100 weight %. Regarding the range of the content of the polymerizable compound having two or more ethylenically unsaturated groups in 100% by weight of the polymerizable component, the lower limit and the upper limit can be appropriately selected and set.

<Polytetrafluoroethylene particles> The above resin particles have a plurality of polytetrafluoroethylene particles (PTFE particles).

In polytetrafluoroethylene particles in which a portion of the polytetrafluoroethylene particles is present on the surface (outside) of the resin particle body, the volume of the portion present on the surface (outside) of the resin particle body out of 100 volume % of the polytetrafluoroethylene particles is preferably 0.01 volume % or more, more preferably 0.1 volume % or more, further preferably 1 volume % or more, further preferably 5 volume % or more, further preferably 10 volume % or more, particularly preferably 20 volume % or more, most preferably 30 volume % or more, and preferably 99 volume % or less, more preferably 95 volume % or less, further preferably 90 volume % or less, particularly preferably 85 volume % or less, and most preferably 80 volume % or less. When the volume of the portion existing on the surface (outside) of the resin particle body is greater than the lower limit and less than the upper limit, the dispersibility of the resin particles in the solvent can be further improved, and the water repellency can be further improved.

From the viewpoint of further improving the dispersibility, in the resin particles, the number of polytetrafluoroethylene particles existing on the surface (outside) of the total number of the polytetrafluoroethylene particles is preferably 5% or more, more preferably 10% or more, further preferably 15% or more, and preferably less than 100%. Furthermore, when one polytetrafluoroethylene particle is observed and all or part of the polytetrafluoroethylene particle exists (exposed) on the surface (outside) of the resin particle body, the polytetrafluoroethylene particle is judged to be equivalent to the polytetrafluoroethylene particle existing on the surface (outside) of the resin particle body. When one polytetrafluoroethylene particle is observed, and at least a portion of the polytetrafluoroethylene particle is present (exposed) on the surface (outside) of the resin particle body, the polytetrafluoroethylene particle is determined to be equivalent to the polytetrafluoroethylene particle present on the surface (outside) of the resin particle body. When one polytetrafluoroethylene particle is observed, and not the entire polytetrafluoroethylene particle is present on the surface (outside) of the resin particle body, the polytetrafluoroethylene particle is determined not to be equivalent to the polytetrafluoroethylene particle present on the surface (outside) of the resin particle body.

In the resin particles, the plurality of polytetrafluoroethylene particles may be dispersed on the surface (outside) of the resin particle body, or may be concentrated. In order to further improve the water repellency and further effectively exert the low dielectric property, the plurality of polytetrafluoroethylene particles in the resin particles are preferably dispersed on the surface (outside) of the resin particle body.

The particle size of the polytetrafluoroethylene particles is preferably 10 nm or more, more preferably 20 nm or more, and further preferably 100 nm or more, and preferably 500 nm or less, more preferably 400 nm or less, and further preferably 350 nm or less. When the particle size of the polytetrafluoroethylene particles is above the lower limit and below the upper limit, the polytetrafluoroethylene particles can be inhibited from agglomerating with each other on the surface or inside the resin particle body.

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 recorded as the ratio (particle size of the polytetrafluoroethylene particles/particle size of the resin particles). The above ratio (particle size of the polytetrafluoroethylene particles/particle size of the resin particles) is preferably 0.001 or more, more preferably 0.01 or more, further preferably 0.03 or more, and preferably 0.5 or less, more preferably 0.3 or less, further 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 greater than or equal to the lower limit and less than or equal to the upper limit, aggregation of polytetrafluoroethylene particles on the surface or inside the resin particle body can be suppressed.

The particle size of the polytetrafluoroethylene particles is a diameter when the polytetrafluoroethylene particles are true spherical, and is a diameter when the polytetrafluoroethylene particles are other than true spherical, assuming a true sphere of equal volume.

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 by any particle size distribution measuring device. For example, the particle size distribution measuring device that utilizes the principles of laser light scattering, resistance value change, image analysis after shooting, etc. can be used for measurement. More specifically, as a method for measuring the particle size of polytetrafluoroethylene particles, the following method can be cited, that is, using a particle size distribution measuring device ("LS13 320" manufactured by Beckman Coulter), the particle size of the polytetrafluoroethylene particles is measured, 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 particles.

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 further 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. With respect to the range of the coefficient of variation (CV value) of the particle size of the polytetrafluoroethylene particles, the lower limit value and the upper limit value may be appropriately selected and set.

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

CV value of the particle size of the above polytetrafluoroethylene particles (%) = (ρ/Dn) × 100 ρ: standard deviation of the particle size of the above polytetrafluoroethylene particles Dn: average value of the particle size of the above polytetrafluoroethylene particles

The shape of the polytetrafluoroethylene particles is not particularly limited. The polytetrafluoroethylene particles may be spherical, other than spherical, or flat.

It is preferred that the number of the polytetrafluoroethylene particles present in the region (R2) from the surface of the resin particle body toward the center to 1/2 of the thickness is greater than the number of the polytetrafluoroethylene particles present in the region (R1) from the center of the resin particle body toward the surface to 1/2 of the thickness. In this case, the water repellency can be further improved, and the low dielectric property can be further effectively exerted. From the viewpoint of further improving the water repellency and further effectively exerting the low dielectric property, it is preferred that the number of the polytetrafluoroethylene particles present on the surface of the resin particle body is greater than the number of the polytetrafluoroethylene particles present in the interior of the resin particle body.

The amount of the polytetrafluoroethylene particles present in the region (R1) and the region (R2) can be measured, for example, in the following manner.

The resin particles were added to the epoxy resin so that the content reached 30% by weight and dispersed to prepare an embedded resin body for resin particle inspection. The cross section of the resin particle was cut out by using a CP (Crosssection Polisher) ("IB-09010CP" manufactured by NEC Corporation) in a manner passing through the vicinity of the center of the resin particle dispersed in the embedded resin body for resin particle inspection. Then, using a FIB-SEM (Focused Ion Beam Scanning Electron Microscopy) ("Helios Nanolab 650" manufactured by FEI Corporation), 10 resin particles were randomly selected under the conditions of 10 kV and 200 pA, and the polytetrafluoroethylene particles of each resin particle were observed. In the cross section of the resin particle, the number of the polytetrafluoroethylene particles present in the region (R2) from the surface of the resin particle body toward the center to 1/2 of the thickness and the number of the polytetrafluoroethylene particles present in the region (R1) from the center of the resin particle body toward the surface to 1/2 of the thickness are measured, and the average is calculated.

The ratio of the number of the polytetrafluoroethylene particles in the region (R2) to the number of the polytetrafluoroethylene particles in the region (R1) is defined as the ratio (the number of polytetrafluoroethylene particles in the region (R2)/the number of polytetrafluoroethylene particles in the region (R1)). The ratio (the number of polytetrafluoroethylene particles in the region (R2)/the number of polytetrafluoroethylene particles in the region (R1)) is preferably 1.0 or more, more preferably 2.0 or more, further preferably 3.0 or more, and particularly preferably 4.0 or more. When the ratio (the number of polytetrafluoroethylene particles in the region (R2)/the number of polytetrafluoroethylene particles in the region (R1)) is greater than the lower limit, the water repellency can be further improved and the dielectric loss factor can be further reduced. The above ratio (the number of polytetrafluoroethylene particles present in the region (R2)/the number of polytetrafluoroethylene particles present in the region (R1)) may be 100 or less, 50 or less, or 10 or less. Regarding the range of the above ratio (the number of polytetrafluoroethylene particles present in the region (R2)/the number of polytetrafluoroethylene particles present in the region (R1)), the above lower limit value and the above upper limit value may be appropriately selected and set.

In 100 wt % of the resin particles, the content of the polytetrafluoroethylene particles is preferably 0.01 wt % or more, more preferably 0.1 wt % or more, further preferably 1.0 wt % or more, particularly preferably 3.0 wt % or more, and preferably 35 wt % or less, more preferably 30 wt % or less, further preferably 20 wt % or less, particularly preferably 15 wt % or less, and most preferably 10 wt % or less. When the content of the polytetrafluoroethylene particles is above the lower limit and below the upper limit, the water repellency can be further improved, and the low dielectric property can be further effectively exerted. 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.

Relative to 100 parts by weight of the resin particle body, the content of the polytetrafluoroethylene particles is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, further preferably 1.0 parts by weight or more, particularly preferably 3.0 parts by weight or more, and preferably 40 parts by weight or less, more preferably 30 parts by weight or less, further 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 further effectively exerted. 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.

<Other components> The resin particles and the resin particle body may contain other components as needed. 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.

The resin particles may or may not contain a surfactant. Examples of the surfactant include anionic surfactants such as carboxylate salts, sulfonate salts, sulfate salts, and phosphate salts, cationic surfactants such as amine salts and ammonium salts, amphoteric surfactants, ester-type and ether-type nonionic surfactants, and fluorine-based surfactants such as per(poly)fluoroalkyl.

From the perspective of reducing environmental load, the resin particles preferably contain a surfactant at a content of 1% by weight or less, or do not contain a surfactant, in 100% by weight of the resin particles. When the resin particles contain the surfactant, the content of the surfactant in 100% by weight of the resin particles is preferably 0.5% by weight or less, more preferably 0.1% by weight or less, and further preferably 0.01% by weight or less. From the perspective of reducing environmental load, the resin particles more preferably do not contain a surfactant.

(Circuit board with insulating layer) The resin particles are preferably used to obtain a circuit board with insulating layer. As an example of the circuit board with insulating layer, there can be cited a circuit board with insulating layer, which comprises a circuit board and an insulating layer arranged on the surface of the circuit board, and the insulating layer contains the resin particles.

In the above-mentioned circuit substrate with insulating layer, the above-mentioned insulating layer is preferably laminated on the surface of the circuit substrate on which the circuit is provided. In the above-mentioned circuit substrate with insulating layer, a part of the above-mentioned insulating layer is preferably embedded between the above-mentioned circuits.

Specific examples of the above-mentioned circuit substrate with an insulating layer include a multi-layer substrate and a multi-layer printed wiring board.

As an example of the multilayer substrate, there can be cited a multilayer substrate having a circuit substrate and an insulating layer laminated on the circuit substrate. The insulating layer of the multilayer substrate comprises the resin particles. The insulating layer is preferably laminated on the surface of the circuit substrate on which the circuit (metal layer) is provided. A portion of the insulating layer is preferably embedded between the circuits. The multilayer substrate is preferably further provided with a copper-plated layer laminated on the surface of the insulating layer.

As another example of the multilayer substrate, there can be cited a multilayer substrate comprising: a circuit substrate, an insulating layer laminated on a surface of the circuit substrate, and a copper foil laminated on a surface of the insulating layer opposite to a surface on which the circuit substrate is laminated.

As another example of the multilayer substrate, there can be cited a multilayer substrate comprising: a circuit substrate and a plurality of insulating layers laminated on a surface of the circuit substrate. At least one of the plurality of insulating layers disposed on the circuit substrate contains the resin particles. The multilayer substrate preferably further comprises a circuit laminated on at least one surface of the insulating layer.

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

FIG3 is a cross-sectional view schematically showing a multi-layer printed wiring board using the resin particles according to the first embodiment of the present invention.

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

In the multilayer printed wiring board 11, the insulating layers 13 to 16 include resin particles 1. In addition, in the multilayer printed wiring board 11, good insulation reliability is imparted between the upper metal layer 17 and the lower metal layer 17 which are not connected by via connection and through-hole connection (not shown). In the present embodiment, all the insulating layers 13 to 16 include resin particles 1, but at least one of the insulating layers 13 to 16 only needs to include resin particles 1. In addition, resin particles such as resin particles 1A may be used instead of resin particles 1. Furthermore, in FIG. 3, the resin particles 1 are shown in a schematic diagram.

Furthermore, the resin particles can also be used in copper foil laminates. As an example of the copper foil laminate, there can be cited a copper foil laminate comprising a copper foil and an insulating layer laminated on one surface of the copper foil. The insulating layer of the copper foil laminate contains the resin particles.

The present invention is specifically described below with reference to embodiments and comparative examples. The present invention is not limited to the following embodiments.

Prepare the following materials.

(Material of resin particles) Styrene ("Styrene Monomer" manufactured by NS Styrene Monomer) Divinylbenzene ("DVB960" manufactured by NS Styrene Monomer) 2-(Perfluorohexyl)ethyl acrylate (manufactured by Fuji Film Co., Ltd. and Wako Pure Chemical Industries, Ltd.) Methyl methacrylate ("Acryester M" manufactured by Mitsubishi Chemical) Ethylene glycol dimethacrylate ("Acryester ED" manufactured by Mitsubishi Chemical) N-Alkylbismaleimide compound ("BMI-689" manufactured by Designer Molecules Inc.)

Polytetrafluoroethylene particles ("KTL-500F" manufactured by Kitamura Co., Ltd., average particle size 300 nm)

(Example 1) Add 50 parts by weight of divinylbenzene and 0.01 parts by weight of polytetrafluoroethylene particles to 49.99 parts by weight of styrene and stir to obtain a monomer solution in which polytetrafluoroethylene particles are dispersed. Then, add 1 part by weight of a free radical polymerization initiator (tert-butyl-2-ethyl peroxyhexanoate, "PERBUTYL O" manufactured by NOF Corporation) to the obtained monomer solution and stir until it becomes uniform to obtain a monomer mixed solution. Add 200 parts by weight of a 1.0% aqueous solution obtained by dissolving polyvinyl alcohol having a molecular weight of about 2000 in pure water to a reactor. Add the obtained monomer mixed solution to the aqueous solution in the reactor and stir until the droplets of the monomer reach a specified particle size. Then, the monomer droplets were polymerized at 90°C for 9 hours to obtain particles. The obtained particles were washed 3 times with hot water and acetone, and then graded to recover the resin particles. Among the obtained resin particles, in at least one polytetrafluoroethylene particle, a portion of the polytetrafluoroethylene particle existed inside the resin particle body, and a portion of the polytetrafluoroethylene particle existed (exposed) on the surface (outside) of the resin particle body.

(Examples 2 to 6, 8 to 16) Except that the type and content (weight %) of the material of the resin particle body and the content (weight %) of the polytetrafluoroethylene particles are changed to those shown in Tables 1 to 4, the resin particles are prepared in the same manner as in Example 1.

(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 (weight %) of the polytetrafluoroethylene particles were changed to those shown in Table 2 and the concentration of polyvinyl alcohol was changed from a 1.0 weight % aqueous solution to a 5.0 weight % aqueous solution. In the obtained resin particles, all of the above polytetrafluoroethylene particles were present inside the resin particle body.

(Comparative Example 1) Instead of using the material of the resin particle body, polytetrafluoroethylene particles are used as the resin particles.

(Comparative Example 2) 5 parts by weight of methyl methacrylate (25% by weight of 100% by weight of the formulated components), 5 parts by weight of ethylene glycol dimethacrylate (25% by weight of 100% by weight of the formulated components), and 0.1 parts by weight of a free radical polymerization initiator (tert-butyl peroxypivalate, "PERBUTYL PV" manufactured by NOF Corporation) 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% by weight of the formulated components) were added to the 100 parts by weight of the obtained acetone solution, and ultrasonic stirring was performed at 50°C for 2 hours. Afterwards, the particles were filtered using a 10 μm mesh filter, washed with methanol, and dried to obtain coated resin particles in which the surface of the polytetrafluoroethylene particles was coated with an acrylic polymer.

(Comparative Examples 3 and 4) The 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 were changed to those shown in Table 4 and polytetrafluoroethylene particles were not used.

(Comparative Example 5) Preparation of fluorinated acrylic particles A: Prepare composition A in a 1000 mL separable flask equipped with a four-mouth separable cover, a stirring blade, a three-way stopcock, a cooling tube, and a temperature probe. The composition A contains 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. After adding 900 parts by weight of distilled water to composition A, stir at 200 rpm and polymerize at 60°C for 24 hours under a nitrogen atmosphere. After the reaction is completed, freeze-drying is performed to obtain fluorinated acrylic particles A.

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 to those shown in Table 5, and the obtained fluorinated acrylic particles A were used in place of polytetrafluoroethylene particles according to the content shown in Table 5.

(Comparative Example 6) The resin particle body was 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 to those shown in Table 5. 10 parts by weight of the fluorinated acrylic particles A obtained in Comparative Example 5 and 90 parts by weight of the obtained resin particle body were dispersed in acetone and ultrasonically stirred at 50°C for 30 minutes. Thereafter, after washing with methanol, the particles were dried to obtain resin particles with the fluorinated acrylic particles A fixed on the surface.

(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 to those shown in Table 5, and the fluorinated acrylic particles A obtained in Comparative Example 5 were used in the content shown in Table 5 instead of the polytetrafluoroethylene particles.

(Comparative Example 8) The resin particle body was 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 to those shown in Table 5. 10 parts by weight of the fluorinated acrylic particles A obtained in Comparative Example 5 and 90 parts by weight of the obtained resin particle body were dispersed in acetone and ultrasonically stirred at 50°C for 30 minutes. Thereafter, after washing with methanol, the particles were dried to obtain resin particles with the fluorinated acrylic particles A fixed on the surface.

(Evaluation) (1) Average particle size The particle size distribution measuring device ("Multisizer4" manufactured by Beckman Coulter) was used to measure the particle sizes of approximately 100,000 particles of the obtained resin particles, and the average particle size was measured.

(2) CV value of particle size For the obtained resin particles, the CV value of particle size was calculated using the above method.

(3) Aspect ratio For the obtained resin particles, the aspect ratio is calculated using the above method.

(4) Specific gravity For the obtained resin particles, calculate the specific gravity using the above method.

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

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

(7) Ratio (the number of polytetrafluoroethylene particles existing in region (R2)/the number of polytetrafluoroethylene particles existing in region (R1)) For the obtained resin particles, the above method is used to measure the number of polytetrafluoroethylene particles existing in region (R2) from the surface of the resin particle body toward the center to 1/2 of the thickness, and the number of polytetrafluoroethylene particles existing in region (R1) from the center of the resin particle body toward the surface to 1/2 of the thickness. Then, the ratio (the number of polytetrafluoroethylene particles existing in region (R2)/the number of polytetrafluoroethylene particles existing in region (R1)) is calculated. Furthermore, in Comparative Examples 5 and 7, the ratio (the amount of fluorinated acrylic particles A present in region (R2)/the amount of fluorinated acrylic particles A present in region (R1)) was calculated.

(8) Dispersibility of resin particles in solvents (presence of aggregation) As solvents, water, acetone, and epoxy resin (bisphenol A type epoxy resin, "jER" manufactured by Mitsubishi Chemical Co., Ltd.) were prepared. One part by weight of the obtained resin particles was dispersed in 100 parts by weight of each solvent, and an optical microscope ("VH-Z450" manufactured by Keyence Corporation) was used to measure the average particle size of the resin particles when dispersed in each solvent, and to observe whether the resin particles aggregated. Furthermore, when the average particle size of the resin particles when dispersed in each solvent was more than twice the average particle size of the resin particles, it was judged that aggregation occurred. The comprehensive evaluation of the dispersibility (presence of agglomeration) of resin particles in various solvents is determined according to the following criteria.

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

(9) Inkjet ejection properties 10 parts by weight of the obtained resin particles were dispersed in a mixture of 50 parts by weight of epoxy resin (bisphenol A type epoxy resin, "jER" manufactured by Mitsubishi Chemical Co., Ltd.) and 50 parts by weight of glycidyl ether to obtain a composition A. The composition A was ejected onto a substrate through an inkjet head of a piezoelectric inkjet printer with an ultraviolet irradiation device. When drawing using the above inkjet printer, the ejection properties of the above composition A were visually evaluated, and the ejection properties were determined according to the following criteria. Furthermore, in the spray test of composition A with a viscosity of less than 500 mPa·s, the nozzle temperature is set to 80°C, and in the spray test of composition A with a viscosity of more than 500 mPa·s, the nozzle temperature is set to 95°C.

[Inkjet jetting criteria] ○○○: Composition A can be ejected from the nozzle continuously for more than 1 hour ○○: Composition A can be ejected from the nozzle continuously for more than 1 hour, but slight uneven ejection occurs during the 1-hour continuous ejection ○: Composition A can be ejected from the nozzle continuously, but cannot be ejected continuously for more than 1 hour ×: Composition A cannot be ejected from the nozzle in the initial stage of ejection

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

[Criteria for determining low dielectric properties of films] ○○○: Dielectric loss factor less than 0.003 ○○: Dielectric loss factor greater than 0.003 and less than 0.006 ○: Dielectric loss factor greater than 0.006 and less than 0.010 ×: Dielectric loss factor greater than 0.010

(11) Hydrophobicity of the membrane For the obtained membrane, 1 ml of water was added to the membrane and the contact angle of water relative to the membrane was measured. The hydrophobicity of the membrane was determined according to the following criteria.

[Criteria for judging the water repellency of the membrane] ○○○: The contact angle is 130° or more ○○: The contact angle is 110° or more but less than 130° ○: The contact angle is 90° or more but less than 110° ×: The contact angle is less than 90°

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

[Table 1] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Mixing ingredients Styrene weight% 49.99 49.9 45 40 25 Divinylbenzene weight% 50 50 50 50 50 2-(Perfluorohexyl)ethyl acrylate weight% Methyl Methacrylate weight% Ethylene glycol dimethacrylate weight% N-Alkylbismaleimide compounds weight% Polytetrafluoroethylene particles weight% 0.01 0.1 5 10 25 Fluorinated acrylic particles A weight% Resin particles Average particle size μm 5.0 5.0 5.0 5.0 5.0 CV value of particle size % 15 11 9 13 18 Aspect ratio - 1.0 1.0 1.0 1.0 1.05 proportion - 1.21 1.21 1.28 1.33 1.47 Dielectric constant F/m 2.51 2.47 2.35 2.29 2.20 Dielectric dissipation factor - 0.0089 0.0065 0.0023 0.0010 0.00090 Ratio (the number of polytetrafluoroethylene particles in region (R2)/the number of polytetrafluoroethylene particles in region (R1)) - 3.5 4.0 4.5 4.5 4.0 evaluate Dispersion of resin particles in solvent (whether there is aggregation) water - without without without without without acetone - without without without without without Epoxy - without without without without without Comprehensive Assessment - ○ ○ ○ ○ ○ Inkjet printability - ○○○ ○○○ ○○○ ○○○ ○○ Low dielectric properties of the film - ○ ○○ ○○○ ○○○ ○○○ Water repellency of membrane - ○ ○○ ○○○ ○○○ ○○○

[Table 2] Embodiment 6 Embodiment 7 Embodiment 8 Embodiment 9 Embodiment 10 Mixing ingredients Styrene weight% 15 45 45 45 45 Divinylbenzene weight% 50 50 50 50 50 2-(Perfluorohexyl)ethyl acrylate weight% Methyl Methacrylate weight% Ethylene glycol dimethacrylate weight% N-Alkylbismaleimide compounds weight% Polytetrafluoroethylene particles weight% 35 5 5 5 5 Fluorinated acrylic particles A weight% Resin particles Average particle size μm 5.0 5.0 5.0 5.0 20.0 CV value of particle size % 20 17 5 35 10 Aspect ratio - 1.1 1.0 1.0 1.0 1.0 proportion - 1.55 1.28 1.28 1.28 1.33 Dielectric constant F/m 2.21 2.49 2.35 2.35 2.35 Dielectric dissipation factor - 0.00080 0.0056 0.0023 0.0023 0.0025 Ratio (the number of polytetrafluoroethylene particles in region (R2)/the number of polytetrafluoroethylene particles in region (R1)) - 3.5 2.0 4.5 4.5 4.5 evaluate Dispersibility of resin particles in solvent (whether there is aggregation) water - without without without without without acetone - without without without without without Epoxy - without without without without without Comprehensive Assessment - ○ ○ ○ ○ ○ Inkjet printability - ○ ○○○ ○○○ ○ ○○○ Low dielectric properties of the film - ○○ ○○ ○○○ ○○○ ○○○ Water repellency of membrane - ○○ ○ ○○○ ○○○ ○○○

[Table 3] Embodiment 11 Embodiment 12 Embodiment 13 Embodiment 14 Embodiment 15 Mixing ingredients Styrene weight% 45 45 40 Divinylbenzene weight% 50 50 50 45 2-(Perfluorohexyl)ethyl acrylate weight% 5 Methyl Methacrylate weight% 45 Ethylene glycol dimethacrylate weight% 50 N-Alkylbismaleimide compounds weight% 50 Polytetrafluoroethylene particles weight% 5 5 5 5 5 Fluorinated acrylic particles A weight% Resin particles Average particle size μm 50.0 100.0 5.0 5.0 5.0 CV value of particle size % 11 10 19 10 10 Aspect ratio - 1.0 1.0 1.0 1.0 1.0 proportion - 1.33 1.33 1.30 1.32 1.12 Dielectric constant F/m 2.36 2.37 2.34 2.50 2.20 Dielectric dissipation factor - 0.0050 0.0085 0.00096 0.0096 0.0010 Ratio (the number of polytetrafluoroethylene particles in region (R2)/the number of polytetrafluoroethylene particles in region (R1)) - 4.5 4.5 4.5 4.5 4.5 evaluate Dispersibility of resin particles in solvent (whether there is aggregation) water - without without without without without acetone - without without without without without Epoxy - without without without without without Comprehensive Assessment - ○ ○ ○ ○ ○ Inkjet printability - ○○ ○ ○○ ○○○ ○○○ Low dielectric properties of the film - ○○ ○ ○○○ ○ ○○○ Water repellency of membrane - ○○ ○ ○○○ ○○ ○○○

[Table 4] Embodiment 16 Comparison Example 1 Comparison Example 2 Comparison Example 3 Comparison Example 4 Mixing ingredients Styrene weight% 45 50 Divinylbenzene weight% 50 50 2-(Perfluorohexyl)ethyl acrylate weight% Methyl Methacrylate weight% 25 50 Ethylene glycol dimethacrylate weight% 25 50 N-Alkylbismaleimide compounds weight% Polytetrafluoroethylene particles weight% 5 100 50 Fluorinated acrylic particles A weight% Resin particles Average particle size μm 1.0 0.3 0.4 5.0 5.0 CV value of particle size % 10 39 40 15 14 Aspect ratio - 1.0 2.1 2.1 1.0 1.0 proportion - 1.33 2.21 2.11 1.20 1.24 Dielectric constant F/m 2.33 1.87 2.01 2.64 2.73 Dielectric dissipation factor - 0.0020 0.00015 0.0011 0.012 0.018 Ratio (the number of polytetrafluoroethylene particles in region (R2)/the number of polytetrafluoroethylene particles in region (R1)) - 4.5 - - - - evaluate Dispersibility of resin particles in solvent (whether there is aggregation) water - without have have without without acetone - without have have without without Epoxy - without have have without without Comprehensive Assessment - ○ × × ○ ○ Inkjet printability - ○○ × × ○○○ ○○○ Low dielectric properties of the film - ○○○ ○○○ ○○ × × Water repellency of membrane - ○○ ○○○ × × ×

[Table 5] Comparison Example 5 Comparison Example 6 Comparative Example 7 Comparative Example 8 Mixing ingredients Styrene weight% 40 40 Divinylbenzene weight% 50 50 2-(Perfluorohexyl)ethyl acrylate weight% Methyl Methacrylate weight% 40 40 Ethylene glycol dimethacrylate weight% 50 50 N-Alkylbismaleimide compounds weight% Polytetrafluoroethylene particles weight% Fluorinated acrylic particles A weight% 10 10 10 10 Resin particles Average particle size μm 5.0 5.0 5.0 5.0 CV value of particle size % 19 twenty four 18 twenty two Aspect ratio - 1.0 1.2 1.0 1.2 proportion - 1.25 1.25 1.21 1.21 Dielectric constant F/m 2.73 2.73 2.64 2.64 Dielectric dissipation factor - 0.018 0.018 0.012 0.012 Ratio (the number of polytetrafluoroethylene particles in region (R2)/the number of polytetrafluoroethylene particles in region (R1)) - 4.5 - 4.5 - evaluate Dispersibility of resin particles in solvent (whether there is aggregation) water - without without without without acetone - without without without without Epoxy - without without without without Comprehensive Assessment - ○ ○ ○ ○ Inkjet printability - ○ ○ ○ ○ Low dielectric properties of the film - × × × × Water repellency of membrane - × × × ×

As shown in Tables 4 and 5, the following results can be obtained. In Comparative Example 1, which does not contain the resin particle body but only polytetrafluoroethylene particles (PTFE particles), the dispersibility of the resin particles in the solvent and the ink jet ejection property are poor. In addition, in Comparative Example 2, in which the surface of the polytetrafluoroethylene particles is coated with an acrylic polymer, the dispersibility of the resin particles in the solvent, the ink jet ejection property, and the water repellency of the film are poor. In Comparative Examples 3 and 4, which do not contain polytetrafluoroethylene particles, the low dielectric and water repellency of the film are poor. In addition, in Comparative Examples 5 to 8, in which fluorine-containing acrylic particles A are used instead of polytetrafluoroethylene particles, the low dielectric and water repellency of the film are poor.

1: Resin particles 1A: Resin particles 2: Resin particles 3: Polytetrafluoroethylene particles 3A: Polytetrafluoroethylene particles 11: Multilayer printed wiring board (circuit board with insulating layer) 12: Circuit board 12a: Upper surface 13: Insulating layer 14: Insulating layer 15: Insulating layer 16: Insulating layer 17: Metal layer

FIG. 1 is a cross-sectional view schematically showing a resin particle of the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a resin particle of the second embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a multi-layer printed wiring board using the resin particle of the first embodiment of the present invention.

1: Resin particles

2: Resin particle body

3: Polytetrafluoroethylene particles

Claims (12)

A resin particle, comprising a resin particle body and a plurality of polytetrafluoroethylene particles, wherein the plurality of polytetrafluoroethylene particles exist only on the surface of the resin particle body and in the interior of the resin particle body, or exist on both the surface of the resin particle body and in the interior of the resin particle body, wherein the resin particle body is a polymer of a polymerizable component, wherein the polymerizable component includes a polymerizable compound having one or more ethylenically unsaturated groups. The resin particles of claim 1, wherein the particle size of the polytetrafluoroethylene particles is greater than 10 nm and less than 500 nm. The resin particles of claim 1 or 2, wherein the particle size of the resin particles is greater than 0.5 μm. The resin particles of claim 1 or 2, wherein the CV value of the particle size of the resin particles is less than 30%. The resin particle of claim 1 or 2, wherein the aspect ratio of the resin particle is less than 1.5. The resin particles of claim 1 or 2, wherein the specific gravity of the resin particles is less than 1.6. The resin particles of claim 1 or 2, wherein the content of the polytetrafluoroethylene particles in 100 wt % of the resin particles is 0.01 wt % to 35 wt %. The resin particle of claim 1 or 2, wherein the dielectric constant of the resin particle is less than 2.60 F/m. The resin particle of claim 1 or 2, wherein the dielectric dissipation factor of the resin particle is less than 0.010. The resin particle of claim 2, wherein in at least one of the plurality of polytetrafluoroethylene particles, a portion of the polytetrafluoroethylene particles is present inside the resin particle body, and a portion of the polytetrafluoroethylene particles is present on the surface of the resin particle body. A resin particle as claimed in claim 1 or 2, wherein the number of the polytetrafluoroethylene particles present in the region from the surface of the resin particle body toward the center to 1/2 of the thickness is greater than the number of the polytetrafluoroethylene particles present in the region from the center of the resin particle body toward the surface to 1/2 of the thickness. A circuit substrate with an insulating layer, comprising: a circuit substrate; and an insulating layer disposed on the surface of the circuit substrate; and the insulating layer comprises resin particles as recited in any one of claims 1 to 11.