阅读说明：本技术 树脂粒子、导电性粒子、导电材料、粘接剂、连接结构体以及液晶显示元件 (Resin particle, conductive material, adhesive, connection structure, and liquid crystal display element ) 是由 有村启太 山田恭幸 于 2018-06-08 设计创作，主要内容包括：本发明提供一种能够有效抑制回弹的发生,并且能够有效地抑制浮起或剥离的发生的树脂粒子。本发明的树脂粒子,其为具有一个聚合性官能团且具有环状有机基团的第一聚合性化合物与具有两个以上聚合性官能团且具有环状有机基团的第二聚合性化合物的聚合物,来自所述第一聚合性化合物的结构的含量与来自所述第二聚合性化合物的结构的含量的重量比为7以上,将树脂粒子在150℃下加热1000小时时,加热后的树脂粒子的粒径与加热前的树脂粒子的粒径之比为0.9以下。(Provided is a resin particle which can effectively suppress the occurrence of springback and can effectively suppress the occurrence of floating or peeling. The resin particles of the present invention are a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group, wherein the weight ratio of the content of a structure derived from the first polymerizable compound to the content of a structure derived from the second polymerizable compound is 7 or more, and when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle diameter of the resin particles after heating to the particle diameter of the resin particles before heating is 0.9 or less.)

1. A resin particle which is a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group,

the weight ratio of the content of the structure derived from the first polymerizable compound to the content of the structure derived from the second polymerizable compound is 7 or more,

when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle diameter of the resin particles after heating to the particle diameter of the resin particles before heating is 0.9 or less.

2. The resin particle according to claim 1, wherein a compression recovery rate at 60% compression set is 10% or less.

3. Resin particles according to claim 1 or 2 having a 10% K value of 3000N/mm²The following.

4. Resin particles according to any of claims 1 to 3 having a 30% K value of 1500N/mm²The following.

5. The resin particle according to any one of claims 1 to 4, wherein when the resin particle is heated at 150 ℃ for 1000 hours, the ratio of the 30% K value of the resin particle after heating to the 30% K value of the resin particle before heating is 0.8 or more and 1.5 or less.

6. The resin particle according to any one of claims 1 to 5, wherein the cyclic organic group in the first polymerizable compound and the cyclic organic group in the second polymerizable compound are each a hydrocarbon group.

7. The resin particle according to any one of claims 1 to 6, wherein the cyclic organic group of the first polymer compound is a phenylene group, a cyclohexyl group, or an isobornyl group.

8. The resin particle according to any one of claims 1 to 7, wherein the cyclic organic group in the second polymerizable compound is a phenylene group, a cyclohexyl group, or an isobornyl group.

9. The resin particle according to any one of claims 1 to 8, which contains an acidic phosphate ester compound.

10. The resin particle according to any one of claims 1 to 9, which is used as a spacer; or

A conductive part is formed on the surface to obtain conductive particles having the conductive part.

11. An electroconductive particle comprising the resin particle according to any one of claims 1 to 10 and an electroconductive portion provided on a surface of the resin particle.

12. A conductive material comprising conductive particles and a binder,

the conductive particles have the resin particles according to any one of claims 1 to 10 and a conductive portion provided on the surface of the resin particles.

13. An adhesive comprising the resin particles according to any one of claims 1 to 10 and a binder.

14. A connection structure body is provided with:

a first connection target member having a first electrode on a surface thereof,

a second connection object member having a second electrode on a surface thereof, an

A connecting portion for connecting the first connection target member and the second connection target member,

the material for the connecting part contains the resin particle according to any one of claims 1 to 10,

the first electrode and the second electrode are electrically connected through the connecting portion.

15. A liquid crystal display element includes:

a first liquid crystal display element member,

Member for second liquid crystal display element, and

a spacer provided between the first liquid crystal display element member and the second liquid crystal display element member,

the spacer is the resin particle according to any one of claims 1 to 10.

Technical Field

The present invention relates to a resin particle formed of a resin. The present invention also relates to conductive particles, a conductive material, an adhesive, a connection structure, and a liquid crystal display element using the resin particles.

Background

Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are well known. In the anisotropic conductive material, conductive particles are dispersed in a binder.

The anisotropic conductive material is used for electrically connecting electrodes of various connection target members such as a Flexible Printed Circuit (FPC), a glass substrate, a glass epoxy substrate, and a semiconductor chip to obtain a connection structure. In addition, as the conductive particles, conductive particles having resin particles and conductive portions provided on the surfaces of the resin particles can be used.

In addition, the liquid crystal display element is configured by disposing liquid crystal between two glass substrates. In this liquid crystal display element, in order to keep the distance (gap) between two glass substrates uniform and constant, spacers are used as a gap control material. Resin particles are generally used as the spacer.

As an example of the above conductive particles, patent document 1 below discloses conductive particles having polymer particles and a conductive layer covering the surfaces of the polymer particles. The polymer particles are obtained by polymerizing a copolymerization component containing at least one polyfunctional (meth) acrylate monomer from among polyfunctional (meth) acrylates of a bifunctional (meth) acrylate monomer, a trifunctional (meth) acrylate monomer and a tetrafunctional (meth) acrylate monomer, and a monofunctional (meth) acrylate monomer. The above-mentioned bifunctional (meth) acrylate monomer is 1, 10-decanediol di (meth) acrylate. When the polyfunctional (meth) acrylate contains a bifunctional (meth) acrylate monomer, the copolymerization component contains the monofunctional (meth) acrylate monomer in an amount of 10 to 400 parts by weight based on 100 parts by weight of the bifunctional (meth) acrylate monomer. When the polyfunctional (meth) acrylate contains a tetrafunctional (meth) acrylate monomer, the copolymerization component contains 80 wt% or less of the monofunctional (meth) acrylate monomer per 100 wt% of the tetrafunctional (meth) acrylate monomer and the monofunctional (meth) acrylate monomer. The polymer particles have a compression set recovery rate of 70% or more. The volume expansion ratio of the polymer particles is 1.3 or less.

In addition, as an example of the resin particles used for the conductive particles or the spacers, patent document 2 below discloses highly recoverable resin particles made of a crosslinked (meth) acrylate resin. The average particle diameter of the high recovery resin particles is 1 to 100 μm. The recovery rate of the high-recovery resin particles is 22% or more. The 30% compressive strength of the high recovery resin particles was 1.5kgf/mm²～5.0kgf/mm²。

Disclosure of Invention

Technical problem to be solved by the invention

When conventional resin particles are used as conductive particles or spacers, a force for restoring the compressed resin particles to their original shape may act, causing a phenomenon called springback. When the resin particles used as the conductive particles rebound, the contact area between the conductive particles and the electrode may decrease, and the conduction reliability may decrease. Further, the resin particles used as the spacers rebound, and the spacers do not sufficiently contact the liquid crystal display element member, and the gap control effect may not be sufficiently obtained.

In addition, the conductive material containing the conductive particles and the adhesive, and the adhesive containing the spacer and the adhesive may be exposed to a heating environment during use, and the adhesive may be cured and shrunk. The conventional resin particles may not be sufficiently shrunk during heating and may not be shrunk following the curing of the adhesive. As a result, floating or peeling may occur between the conductive material and the electrode, or between the adhesive and the member for a liquid crystal display element or the like.

The purpose of the present invention is to provide resin particles that can effectively suppress the occurrence of springback and can effectively suppress the occurrence of floating or peeling. Another object of the present invention is to provide conductive particles, a conductive material, an adhesive, a connection structure, and a liquid crystal display element, each of which uses the resin particles.

Means for solving the problems

According to a broad aspect of the present invention, there is provided a resin particle which is a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group, wherein a weight ratio of a content derived from a structure of the first polymerizable compound to a content derived from a structure of the second polymerizable compound is 7 or more, and when the resin particle is heated at 150 ℃ for 1000 hours, a ratio of a particle diameter of the resin particle after heating to a particle diameter of the resin particle before heating is 0.9 or less.

According to a specific aspect of the resin particle of the present invention, the compression recovery rate at 60% compression deformation is 10% or less.

According to a particular aspect of the resin particles according to the invention, the 10% K value is 3000N/mm²The following.

According to a particular aspect of the resin particles according to the invention, the 30% K value is 1500N/mm²The following.

In a specific aspect of the resin particles according to the present invention, when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the 30% K value of the resin particles after heating to the 30% K value of the resin particles before heating is 0.8 or more and 1.5 or less.

In a specific aspect of the resin particle according to the present invention, the cyclic organic group in the first polymerizable compound and the cyclic organic group in the second polymerizable compound are each a hydrocarbon group.

In a specific aspect of the resin particle according to the present invention, the cyclic organic group of the first polymer compound is a phenylene group, a cyclohexyl group, or an isobornyl group.

In a specific aspect of the resin particle according to the present invention, the cyclic organic group in the second polymerizable compound is a phenylene group, a cyclohexyl group, or an isobornyl group.

According to a specific aspect of the resin particle of the present invention, it contains an acidic phosphate ester compound.

According to a specific aspect of the resin particle of the present invention, it functions as a spacer; or forming a conductive portion on the surface to obtain conductive particles having the conductive portion.

According to a broad aspect of the present invention, there is provided an electrically conductive particle comprising the resin particle according to any one of claims 1 to 10 and an electrically conductive portion provided on a surface of the resin particle.

According to a broad aspect of the present invention, there is provided a conductive material containing conductive particles having the resin particles and a conductive portion provided on a surface of the resin particles, and a binder.

According to a broad aspect of the present invention, there is provided an adhesive comprising the resin particles and a binder.

According to a broad aspect of the present invention, there is provided a connection structure comprising: a first member to be connected having a first electrode on a surface thereof, a second member to be connected having a second electrode on a surface thereof, and a connecting portion for connecting the first member to be connected and the second member to be connected, wherein a material of the connecting portion contains the resin particle according to any one of claims 1 to 10, and the first electrode and the second electrode are electrically connected through the connecting portion.

According to a broad aspect of the present invention, there is provided a liquid crystal display element comprising: the liquid crystal display device includes a first liquid crystal display element member, a second liquid crystal display element member, and a spacer provided between the first liquid crystal display element member and the second liquid crystal display element member, wherein the spacer is the resin particle.

ADVANTAGEOUS EFFECTS OF INVENTION

The resin particle of the present invention is a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group, and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group. In the resin particle of the present invention, the weight ratio of the content of the structure derived from the first polymerizable compound to the content of the structure derived from the second polymerizable compound is 7 or more. In the resin particles of the present invention, when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle diameter of the resin particles after heating to the particle diameter of the resin particles before heating is 0.9 or less. The resin particles of the present invention, having the above technical features, can effectively suppress the occurrence of springback and can effectively suppress the occurrence of floating or peeling.

Drawings

Fig. 1 is a sectional view showing conductive particles according to a first embodiment of the present invention.

Fig. 2 is a sectional view showing conductive particles according to a second embodiment of the present invention.

Fig. 3 is a sectional view showing conductive particles according to a third embodiment of the present invention.

Fig. 4 is a cross-sectional view showing an example of a connection structure using conductive particles according to the first embodiment of the present invention.

FIG. 5 is a sectional view showing an example of a connection structure using the resin particles of the present invention.

Fig. 6 is a cross-sectional view showing an example of a liquid crystal display element using the resin particles of the present invention as spacers for liquid crystal display.

Detailed Description

Hereinafter, the present invention will be described in detail.

(resin particles)

The resin particle of the present invention is a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group, and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group. In the resin particle of the present invention, the weight ratio of the content of the structure derived from the first polymerizable compound to the content of the structure derived from the second polymerizable compound is 7 or more. In the resin particles of the present invention, when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle size of the resin particles after heating to the particle size of the resin particles before heating is 0.9 or less. In the resin particle of the present invention, the weight ratio (WM/WD) of the content (WM) of the structure derived from the first polymerizable compound to the content (WD) of the structure derived from the second polymerizable compound is 7 or more. In the resin particles of the present invention, when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle size of the resin particles after heating to the particle size of the resin particles before heating (particle size of the resin particles after heating/particle size of the resin particles before heating) is 0.9 or less.

The present invention has the above technical features, and therefore, occurrence of springback can be effectively suppressed, and occurrence of floating or peeling can be effectively suppressed.

The resin particles of the present invention have the above-described technical features, and therefore, the compression recovery rate is relatively low, and the force for restoring the compressed resin particles to their original shape is relatively hard to act, and the occurrence of springback is difficult. For example, when the resin particles of the present invention are used as conductive particles, the reduction in the contact area between the conductive particles and the electrodes can be effectively prevented, and the conduction reliability between the electrodes can be effectively improved. When the resin particles of the present invention are used as spacers, the spacers can be brought into sufficient contact with a member for a liquid crystal display element or the like, and the gap can be controlled with higher accuracy.

In addition, a conductive material containing conductive particles and a binder, and an adhesive containing a spacer and a binder may be exposed to a heating environment during use, and the binder may be cured and shrunk by heating. The resin particle of the present invention has the above-described technical features, and the resin particle is relatively easily shrunk by heating. The particle diameter of the resin particles after heating is suitably smaller than the particle diameter of the resin particles before heating, and therefore the resin particles can follow the curing shrinkage of the binder. As a result, the occurrence of floating or peeling between the conductive material and the electrode or between the adhesive and the member for a liquid crystal display element or the like can be effectively suppressed.

In the resin particle of the present invention, the weight ratio (WM/WD) of the content (WM) of the structure derived from the first polymerizable compound to the content (WD) of the structure derived from the second polymerizable compound is 7 or more. From the viewpoint of more effectively suppressing the occurrence of springback and more effectively suppressing the occurrence of floating or peeling, the weight ratio (WM/WD) is preferably 9 or more, more preferably 13 or more, preferably 20 or less, and more preferably 17 or less.

The following methods can be mentioned as a method for obtaining the content (WM) of the structure derived from the first polymerizable compound and the content (WD) of the structure derived from the second polymerizable compound. The amounts of the first polymerizable compound and the second polymerizable compound which were polymerized were determined from the amounts of the first polymerizable compound and the second polymerizable compound which were used in obtaining the polymer and the amounts of the first polymerizable compound and the second polymerizable compound which were polymerized, and the amounts of the first polymerizable compound and the second polymerizable compound which were polymerized were calculated from the amounts of the first polymerizable compound and the second polymerizable compound which were polymerized.

In addition, as a method of obtaining the content (WM) of the structure derived from the first polymerizable compound and the content (WD) of the structure derived from the second polymerizable compound from the resin particles, the following method can be mentioned. The amount of the groups obtained by reacting the amount of the functional groups in the resin particles of the first polymerizable compound and the second polymerizable compound used for obtaining the polymer and the amount of the functional groups in the resin particles of the first polymerizable compound and the second polymerizable compound used for obtaining the polymer was calculated.

In the resin particles of the present invention, when the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the particle size of the resin particles after heating to the particle size of the resin particles before heating (particle size of the resin particles after heating/particle size of the resin particles before heating) is 0.9 or less. From the viewpoint of further effectively suppressing the occurrence of floating or peeling, the above ratio (particle diameter of the resin particles after heating/particle diameter of the resin particles before heating) is preferably 0.4 or more, more preferably 0.6 or more, preferably 0.85 or less, and more preferably 0.8 or less.

The particle diameter of the resin particles (the particle diameter of the resin particles before heating) can be appropriately set according to the application. The particle diameter of the resin particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 500 μm or less, more preferably 300 μm or less, still more preferably 150 μm or less, further preferably 100 μm or less, and particularly preferably 50 μm or less. When the particle diameter of the resin particles is not less than the lower limit and not more than the upper limit, the occurrence of springback can be more effectively suppressed, and the occurrence of floating or peeling can be more effectively suppressed. When the particle diameter of the resin particles is 0.5 μm or more and 500 μm or less, the resin particles can be suitably used for the purpose of conductive particles. When the particle diameter of the resin particles is 0.5 μm or more and 500 μm or less, the resin particles can be suitably used for the purpose of a spacer.

The particle diameter of the resin particles (the particle diameter of the resin particles before heating and the particle diameter of the resin particles after heating) indicates the diameter when the resin particles are spherical, and indicates the maximum diameter when the resin particles are not spherical.

The particle diameter of the resin particles (the particle diameter of the resin particles before heating and the particle diameter of the resin particles after heating) is preferably an average particle diameter, and more preferably a number average particle diameter. The particle diameter of the resin particles can be measured using a particle size distribution measuring apparatus or the like. For example, a particle size distribution measuring apparatus using the principles of laser scattered light, change in resistance value, image analysis after imaging, and the like can be used. Specifically, as a method for measuring the particle diameter of the resin particles, for example, a method of measuring the particle diameter of about 100000 resin particles using a particle size distribution measuring apparatus ("Multisizer 4" manufactured by Beckman Coulter corporation) and calculating an average value is used. The particle diameter of the resin particles is preferably determined by observing 50 arbitrary resin particles with an electron microscope or an optical microscope and calculating the average value. For example, when the particle diameter of the resin particle is measured in the conductive particle, the measurement can be performed as follows.

For example, conductive particles are added and dispersed in "Technobit 4000" manufactured by Kulzer corporation so that the content of the conductive particles is 30% by weight, to prepare an intercalation resin for conductive particle inspection. The cross section of the conductive particles was cut using an ion milling apparatus ("IM 4000" manufactured by Hitachi High-Technologies Corporation) so that the cross section passed near the center of the conductive particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the resin particles of each conductive particle were observed while randomly selecting 50 conductive particles with an image magnification of 25000 times. The particle diameter of the resin particles in each conductive particle was measured, and the particle diameter was arithmetically averaged to be the particle diameter of the resin particles.

From the viewpoint of more effectively suppressing the occurrence of springback and the viewpoint of more effectively suppressing the occurrence of floating and peeling, the coefficient of variation (CV value) of the particle diameter of the resin particles is preferably 0.5% or more, more preferably 1% or more, and preferably 10% or less, more preferably 7% or less. When the coefficient of variation of the particle diameter of the resin particles is not less than the lower limit and not more than the upper limit, the resin particles are suitably used as a spacer and a conductive particle. However, the coefficient of variation of the particle diameter of the resin particles may be less than 0.5%.

The above coefficient of variation (CV value) can be measured as follows.

CV value (%) - (ρ/Dn) × 100

P: standard deviation of particle diameter of resin particle

Dn: average value of particle diameter of resin particles

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

The 10% K value of the resin particles is preferably 1000N/mm²Above, more preferably 1500N/mm²Above, preferably 3000N/mm²Hereinafter, 2750N/mm is more preferable²More preferably 2500N/mm or less²The following. When the 10% K value of the resin particles is not less than the lower limit and not more than the upper limit, occurrence of springback can be more effectively suppressed, and occurrence of floating or peeling can be more effectively suppressed.

The resin particles preferably have a 30% K value of 300N/mm²Above, more preferably 500N/mm²Above, preferably 1500N/mm²Hereinafter, 1200N/mm is more preferable²Hereinafter, more preferably 1000N/mm²The following. When the 30% K value of the resin particles is not less than the lower limit and not more than the upper limit, occurrence of springback can be more effectively suppressed, and occurrence of floating or peeling can be more effectively suppressed.

When the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the 30% K value of the resin particles after heating to the 30% K value of the resin particles before heating (30% K value of the resin particles after heating/30% K value of the resin particles before heating) is preferably 0.8 or more, more preferably 1.15 or more, and still more preferably 1.2 or more. When the resin particles are heated at 150 ℃ for 1000 hours, the ratio of the 30% K value of the resin particles after heating to the 30% K value of the resin particles before heating (30% K value of the resin particles after heating/30% K value of the resin particles before heating) is preferably 1.5 or less, more preferably 1.45 or less, and still more preferably 1.4 or less. When the above ratio (30% K value of the resin particles after heating/30% K value of the resin particles before heating) is not less than the above lower limit and not more than the above upper limit, occurrence of springback can be more effectively suppressed, and occurrence of floating or peeling can be more effectively suppressed.

The 10% K value and the 30% K value (compressive modulus when the resin particle is compressed by 10% and compressive modulus when the resin particle is compressed by 30%) of the above resin particle can be measured in the following manner.

One conductive particle was compressed with a smooth indenter end face of a cylinder (diameter 100 μm, made of diamond) at a compression speed of 0.3mN/sec and a maximum test load of 20mN using a micro-compression tester. The load value (N) and the compression displacement (mm) at this time were measured. From the obtained measurement values, 10% K value or 30% K value at 25 ℃ can be obtained by the following equation. As the micro-compression tester, for example, "micro-compression tester MCT-W200" manufactured by Shimadzu corporation and "Fisher Scope H-100" manufactured by Fisher corporation can be used. The 10% K value or 30% K value of the above resin particles is preferably calculated by arithmetically averaging 10% K values or 30% K values of arbitrarily selected 50 resin particles.

10% K value or 30% K value (N/mm)²)＝(3/2^1/2)·F·S^-3/2·R^-1/2

F: the load value (N) when the resin particles are compressed and deformed by 10% or the load value (N) when the resin particles are compressed and deformed by 30%

S: the resin particles are compressed and deformed by 10% or 30% in compression displacement (mm)

R: radius of resin particle (mm)

The K value generally and quantitatively represents the hardness of the resin particles. By using the above K value, the hardness of the resin particle can be quantitatively and uniquely expressed.

From the viewpoint of more effectively suppressing the occurrence of springback, and from the viewpoint of more effectively suppressing the occurrence of floating and peeling, the compression recovery rate of 60% of the compression deformation of the resin particles is preferably 2% or more, more preferably 4% or more, preferably 10% or less, more preferably 9.5% or less, and still more preferably 9% or less.

The compression recovery rate of the resin particles subjected to compression deformation of 60% can be measured as follows.

Resin particles are scattered on a sample stage. A load (reverse load value) was applied to one spread conductive particle in the center direction of the conductive particle at 25 ℃ with a smooth indenter end face (diameter 100 μm, manufactured by diamond) of a cylinder until the resin particle compression-deformed 60%, using a micro compression tester. Then, the load was released to the original load value (0.40 mN). The load-compression displacement during this period is measured, and the compression recovery rate at 25 ℃ at compression deformation of 60% can be obtained from the following equation. The load rate was 0.33 mN/sec. As the micro-compression tester, for example, "micro-compression tester MCT-W200" manufactured by Shimadzu corporation, "Fisher scope H-100" manufactured by Fisher corporation, and the like can be used.

Compression recovery rate (%) [ L2/L1] x 100

L1: compressive displacement from an origin load value to a rebound load value upon application of a load

L2: load-shedding displacement from rebound load value to origin load value upon load release

The use of the resin particles is not particularly limited. The resin particles are suitable for various applications. The resin particles are preferably used as a spacer or for obtaining conductive particles having a conductive portion. In the conductive particles, the conductive portion is formed on the surface of the resin particle. The resin particles described above are preferably used as a spacer. The resin particles are preferably used to obtain conductive particles having a conductive portion. Examples of the method of using the spacer include: spacers for liquid crystal display elements, spacers for gap control, spacers for stress relaxation, and the like. The spacer for controlling a gap is used for controlling a gap of a laminated chip for ensuring a height and flatness of a support, and is used for controlling a gap of an optical member for ensuring smoothness of a glass surface and a thickness of an adhesive layer. The stress relaxation spacer can be used for stress relaxation of a sensor chip or the like, stress relaxation of a connection portion connecting two members to be connected, and the like.

The resin particles are preferably used as a spacer for a liquid crystal display element, and are preferably used as a peripheral sealing agent for a liquid crystal display element. In the peripheral sealing agent for a liquid crystal display element, the resin particles preferably function as spacers. Since the resin particles have good compression deformation characteristics, when the resin particles are used as spacers to be provided between substrates and conductive portions are formed on the surfaces thereof, and the resin particles are used as conductive particles to electrically connect electrodes, the spacers or the conductive particles are effectively provided between the substrates or between the electrodes. Further, since the resin particles can suppress damage to a member for a liquid crystal display element or the like, a connection failure and a display failure are less likely to occur in a connection structure using the spacer for a liquid crystal display element and the conductive particles.

Further, the above resin particles are suitably used as an inorganic filler, a toner additive, an impact absorber or a vibration damper. For example, the above resin particles may be used as a substitute for rubber or a spring.

(details of resin particles)

The resin particle of the present invention is a polymer of a first polymerizable compound having one polymerizable functional group and a cyclic organic group, and a second polymerizable compound having two or more polymerizable functional groups and a cyclic organic group. The resin particles are preferably obtained by polymerizing the first polymerizable compound and the second polymerizable compound.

From the viewpoint of more effectively suppressing the occurrence of springback and from the viewpoint of more effectively suppressing the occurrence of floating and peeling, it is preferable that the resin particles are composed of the same polymer as the resin particles at the center portion and the surface portion thereof. The mixing ratio of the polymerizable compound in the central portion of the resin particle and the mixing ratio of the polymerizable compound in the surface portion of the resin particle may be the same or different. The composition ratio of the components in the center of the resin particle may be the same as or different from the composition ratio of the components in the surface of the resin particle.

Preferably, the resin particle has a central portion formed of a central portion-forming material and a surface portion formed of a surface portion-forming material. In the resin particles, the component of the center portion-forming material and the component of the surface portion-forming material are preferably the same from the viewpoint of more effectively suppressing the occurrence of springback and from the viewpoint of more effectively suppressing the occurrence of floating or peeling. In the resin particles, the composition ratio of the central portion forming material and the composition ratio of the surface portion forming material may be the same or different. In addition, in the resin particles, a region including both the central portion forming material and the surface portion forming material is preferably present. In the resin particle, the resin particle preferably has, in a central portion: a region containing the center portion forming material but not containing the surface portion forming material or less than 25% of the surface portion forming material. In the resin particle, the resin particle preferably has: a region containing the surface portion forming material but not containing the center portion forming material or less than 25% of the center portion forming material.

The above resin particle is preferably a non-core-shell particle comprising a core and a shell provided on the surface of the core, and preferably a resin particle having no interface between the core and the shell inside. The resin particles preferably do not have an interface within the resin particles, and more preferably do not have an interface where different surfaces contact each other. The resin particles preferably have no discontinuous portion present on the surface, and preferably have no discontinuous portion present on the surface of the structure.

In the resin particle of the present invention, the first polymerizable compound has one polymerizable functional group (first polymerizable functional group). The polymerizable functional group (first polymerizable functional group) is not particularly limited, and examples thereof include: vinyl, acryloyl, and methacryloyl, and the like. Examples of the first polymerizable compound include: styrene, phenyl methacrylate, phenyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, isobornyl methacrylate, isobornyl acrylate, and the like. The first polymerizable compound may be used alone or in combination of two or more.

In the resin particles of the present invention, the second polymerizable compound has two or more polymerizable functional groups (second polymerizable functional groups). The polymerizable functional group (second polymerizable functional group) is not particularly limited, and examples thereof include: vinyl, acryloyl, and methacryloyl, and the like. As the above-mentioned second polymer compound, there can be exemplified: divinylbenzene, divinylnaphthalene, divinylcyclohexane and trivinylcyclohexane, and the like. The second polymerizable compound may be used alone or in combination of two or more.

The resin particles are obtained by polymerizing the first polymerizable compound and the second polymer compound in a weight ratio (weight of the first polymerizable compound/weight of the second polymerizable compound) of preferably 7 or more, more preferably 9 or more, further preferably 13 or more, preferably 20 or less, more preferably 18.5 or less, and further preferably 17 or less. The resin particles are preferably obtained by polymerizing the first polymerizable compound and the second polymer compound at a weight ratio of 7 or more, more preferably at a weight ratio of 9 or more, and still more preferably at a weight ratio of 13 or more. The resin particles are preferably obtained by polymerizing the first polymerizable compound and the second polymer compound at a weight ratio of 20 or less, more preferably at a weight ratio of 18.5 or less, and still more preferably at a weight ratio of 17 or less. In the resin particles, the weight ratio of the first polymerizable compound to the second polymer compound is polymerized in the preferable range, whereby occurrence of springback can be more effectively suppressed, and occurrence of floating or peeling can be more effectively suppressed.

The resin particles of the present invention preferably contain 2 or more kinds of cyclic organic groups. In the resin particle of the present invention, the first polymerizable compound has a cyclic organic group (first cyclic organic group). The first polymerizable compound has 1 or more cyclic organic groups. In the resin particles of the present invention, the second polymerizable compound has a cyclic organic group (second cyclic organic group). The second polymerizable compound has 1 or more cyclic organic groups. In the resin particle of the present invention, the cyclic organic group (first cyclic organic group) in the first polymerizable compound and the cyclic organic group (second cyclic organic group) in the second polymerizable compound may be the same or different. Preferably, the cyclic organic group (first cyclic organic group) in the first polymerizable compound and the cyclic organic group (second cyclic organic group) in the second polymerizable compound are different.

From the viewpoint of more effectively suppressing the occurrence of springback, and from the viewpoint of more effectively suppressing the occurrence of floating and peeling, it is preferable that the cyclic organic group (first cyclic organic group) in the first polymerizable compound and the cyclic organic group (second cyclic organic group) in the second polymerizable compound are each a hydrocarbon group.

Examples of the hydrocarbon group include: phenyl, phenylene, naphthyl, naphthylene, cyclopropyl, cyclohexyl, isobornyl, dicyclopentanyl and the like.

From the viewpoint of further effectively suppressing the occurrence of springback, and from the viewpoint of further effectively suppressing the occurrence of floating and peeling, the resin particles of the present invention preferably have two or more cyclic organic groups of phenylene, cyclohexyl, and isobornyl groups.

The cyclic organic group (first cyclic organic group) in the first polymerizable compound is preferably a phenylene group, a cyclohexyl group, or an isobornyl group, from the viewpoint of more effectively suppressing the rebound, and from the viewpoint of more effectively suppressing the occurrence of the floating and peeling.

The cyclic organic group (second cyclic organic group) in the second polymerizable compound is preferably a phenylene group, a cyclohexyl group, or an isobornyl group, from the viewpoint of more effectively suppressing the occurrence of rebound, and from the viewpoint of more effectively suppressing the occurrence of floating and peeling.

When the resin particles are used as conductive particles, the resin particles preferably contain an acidic phosphate ester compound from the viewpoint of further effectively improving the adhesion between the resin particles and the plating layer. The resin particles preferably have a phosphoric acid structure derived from an acidic phosphate ester compound on the surface. Since the resin particles have the phosphoric acid structure on the surface, the adhesion to the plating layer can be further effectively improved. Further, since the resin particles have the phosphoric acid structure on the surface, even if the resin particles shrink due to heating, cracking of the plating layer can be further effectively suppressed. For example, even when conductive particles prepared by electroless plating of resin particles containing an acidic phosphate compound and a conductive material containing a binder are heated or exposed to a heating environment during connection between electrodes, cracking of the plated layer can be further effectively suppressed, and the connection reliability between electrodes can be further effectively improved. When the resin particles are used to obtain conductive particles, the resin particles preferably contain an acidic phosphate ester compound. When the resin particles are used to obtain conductive particles, the resin particles preferably have a phosphoric acid structure derived from an acidic phosphate ester compound on the surface. The acidic phosphate ester compound is preferably an acidic phosphate ester compound.

Examples of the acidic phosphate ester compound include: ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosanoic acid phosphate, glycolic acid phosphate, 2-hydroxyethyl methacryloyl acid phosphate, dibutyl acid phosphate, bis (2-ethylhexyl) acid phosphate, and the like. The acidic phosphate ester compounds may be used alone or in combination of two or more.

From the viewpoint of further effectively improving the adhesion between the resin particles and the plating layer, the content of the acidic phosphate ester compound in 100 wt% of the resin particles is preferably 1 wt% or more, more preferably 5 wt% or more, preferably 20 wt% or less, and more preferably 15 wt% or less.

(conductive particles)

The conductive particles of the present invention comprise the resin particles and a conductive portion disposed on the surface of the resin particles.

Fig. 1 is a sectional view showing conductive particles according to a first embodiment of the present invention.

The conductive particle 1 shown in fig. 1 has a resin particle 11 and a conductive portion 2 provided on the surface of the resin particle 11. The conductive portion 2 is in contact with the surface of the resin particle 11. The conductive part 2 covers the surface of the resin particle 11. The conductive particles 1 are coated particles in which the surfaces of the resin particles 11 are covered with the conductive portions 2. In the conductive particle 1, the conductive portion 2 is a single-layer conductive portion (conductive layer).

Fig. 2 is a sectional view showing conductive particles according to a second embodiment of the present invention.

The conductive particles 21 shown in fig. 2 include resin particles 11 and conductive portions 22 provided on the surfaces of the resin particles 11. Conductive portion 22 has first conductive portion 22A located on the resin particle 11 side and second conductive portion 22B located on the opposite side of resin particle 11 side as a whole.

Only the conductive portion 22 is different between the conductive particle 1 shown in fig. 1 and the conductive particle 21 shown in fig. 2. That is, the conductive portion having a single-layer structure is formed on the conductive particle 1, and the first conductive portion 22A and the second conductive portion 22B having a double-layer structure are formed on the conductive particle 21. First conductive portion 22A and second conductive portion 22B may be formed as different conductive portions or may be formed as the same conductive portion.

First conductive portion 22A is provided on the surface of resin particle 11. First conductive portion 22A is provided between resin particle 11 and second conductive portion 22B. First conductive portion 22A is in contact with resin particle 11. Second conductive portion 22B is in contact with first conductive portion 22A. First conductive portion 22A is provided on the surface of resin particle 11, and second conductive portion 22B is provided on the surface of first conductive portion 22A.

Fig. 3 is a sectional view showing conductive particles according to a third embodiment of the present invention.

The conductive particles 31 shown in fig. 3 include resin particles 11, a conductive portion 32, a plurality of core materials 33, and a plurality of insulating materials 34. The conductive portion 32 is provided on the surface of the resin particle 11. The plurality of core substances 33 are provided on the surface of the resin particle 11. The conductive portion 32 is provided on the surface of the resin particle 11, and covers the resin particle 11 and the plurality of core materials 33. In the conductive particles 31, the conductive portion 32 is a single-layer conductive portion (conductive layer).

The conductive particles 31 have a plurality of protrusions 31a on the outer surface. In the conductive particle 31, the conductive portion 32 has a plurality of protrusions 32a on the outer surface. The plurality of core materials 33 swell the outer surface of the conductive portion 32. The outer surface of the conductive portion 32 is raised by the plurality of core substances 33, thereby forming protrusions 31a and 32a. The plurality of core materials 33 are embedded in the conductive portion 32. The core material 33 is disposed inside the protrusions 31a and 32a. In the conductive particles 31, a plurality of core substances 33 are used to form the protrusions 31a and 32a. In the conductive particles, the protrusions may be formed without using the plurality of core materials. The conductive particles may not include the plurality of core materials.

The conductive particles 31 have an insulating material 34 provided on the outer surface of the conductive portion 32. At least a part of the outer surface of the conductive portion 32 is covered with an insulating material 34. The insulating material 34 is made of an insulating material, and is insulating particles. Therefore, the conductive particles of the present invention may have an insulating substance provided on the outer surface of the conductive portion. However, the conductive particles may not necessarily have an insulating substance. The conductive particles may not contain a plurality of insulating materials.

Conductive part:

the metal used to form the conductive portion is not particularly limited. Examples of the metal include: gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum, alloys of the above metals, and the like. Examples of the metal include tin-doped indium oxide (ITO) and solder. Since the connection resistance between the electrodes can be further reduced, an alloy containing tin, nickel, palladium, copper, or gold is preferable, and nickel or palladium is preferable.

Further, since the conduction reliability can be effectively improved, the conductive portion and the outer surface portion of the conductive portion preferably include nickel. The nickel content of 100 wt% of the nickel-containing conductive portion is preferably 10 wt% or more, more preferably 50 wt% or more, further preferably 60 wt% or more, further preferably 70 wt% or more, and particularly preferably 90 wt% or more. The nickel content in 100 wt% of the nickel-containing conductive portion may be 97 wt% or more, 97.5 wt% or more, or 98 wt% or more.

In many cases, hydroxyl groups are present on the surface of the conductive portion due to oxidation. In general, hydroxyl groups are present on the surface of the conductive portion formed of nickel by oxidation. The insulating material may be provided on the surface of the conductive portion having such a hydroxyl group (the surface of the conductive particle) by a chemical bond.

The conductive portion may be formed of one layer, such as the conductive particles 1 and the conductive particles 31. As the conductive particles 21, the conductive portion may be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer, or an alloy layer containing tin and silver, and more preferably a gold layer. When the outermost layer is these preferable conductive portions, the connection resistance between the electrodes can be further effectively reduced. Further, when the outermost layer is a gold layer, the corrosion resistance can be further effectively improved.

The method of forming the conductive portion on the surface of the resin particle is not particularly limited. Examples of the method for forming the conductive portion include: a method by electroless plating, a method by electroplating, a method by physical vapor deposition, a method of coating a metal powder or a paste containing a metal powder and a binder on the surface of the resin particle, and the like. Since the conductive portion can be easily formed, a method of electroless plating is preferable. Examples of the method by physical vapor deposition include: vacuum evaporation, ion plating, ion sputtering, and the like.

The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, preferably 500 μm or less, more preferably 450 μm or less, further preferably 100 μm or less, further preferably 50 μm or less, and particularly preferably 20 μm or less. When the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrodes is sufficiently increased, and it is difficult to form aggregated conductive particles when forming the conductive portion. Further, the distance between the electrodes connected by the conductive particles does not become excessively large, and the conductive portion is not easily peeled off from the surface of the resin particle. When the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, the conductive particles can be suitably used for the conductive material.

The particle diameter of the conductive particle represents a diameter when the conductive particle is in a regular spherical shape, and represents a maximum diameter when the conductive particle is not in a regular spherical shape.

The particle diameter of the conductive particles is preferably an average particle diameter, and more preferably a number average particle diameter. The average particle diameter of the conductive particles is obtained by calculating an average value of, for example, 50 arbitrary conductive particles observed by an electron microscope or an optical microscope; or by performing a plurality of measurements using a laser diffraction particle size distribution measuring apparatus and calculating the average value of the measurement results.

The thickness of the conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and further preferably 0.3 μm or less. When the thickness of the conductive portion is not less than the upper limit and not less than the lower limit, sufficient conductivity is obtained, and the conductive particles do not become too hard and deform sufficiently when the electrodes are connected.

When the conductive portion is formed of a plurality of layers, the thickness of the conductive portion at the outermost layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, and more preferably 0.1 μm or less. When the thickness of the outermost conductive part is equal to or less than the upper limit and equal to or more than the lower limit, the outermost conductive part is uniformly coated, the corrosion resistance is sufficiently improved, and the connection resistance between the electrodes is sufficiently reduced. In addition, when the outermost layer is a gold layer, the thinner the thickness of the gold layer is, the lower the cost is.

The thickness of the conductive portion is measured by, for example, observing the cross section of the conductive particle using a Transmission Electron Microscope (TEM). The thickness of the conductive portion is preferably calculated as an average value of the thicknesses of the optional 5 conductive portions, and more preferably calculated as an average value of the thicknesses of the entire conductive portions. In the case of a plurality of conductive particles, the thickness of the conductive portion is preferably determined by calculating an average value of arbitrary 10 conductive particles.

Core material:

the conductive particles preferably have a plurality of protrusions on an outer surface of the conductive portion. The conductive particles have a plurality of protrusions on the outer surface of the conductive portion, whereby the reliability of conduction between electrodes can be further enhanced. An oxide film is usually formed on the surface of the electrode connected by the conductive particles. In addition, an oxide film is generally formed on the surface of the conductive portion of the conductive particles. By using the conductive particles having the protrusions, the conductive particles are provided between the electrodes, and then by pressing the electrodes, the oxide film is effectively removed by the protrusions. Therefore, the electrode and the conductive particles can be brought into contact with each other more reliably, and the connection resistance between the electrodes can be reduced more effectively. When the conductive particles have an insulating material on the surface thereof or when the conductive particles are dispersed in a binder resin and used as a conductive material, the insulating material and the binder resin between the conductive particles and the electrodes are effectively eliminated by the protrusions of the conductive particles. Therefore, the reliability of conduction between the electrodes can be further effectively improved.

By embedding the core material in the conductive portion, a plurality of protrusions can be easily formed on the outer surface of the conductive portion. However, it may not be necessary to form the protrusions on the surface of the conductive portion of the conductive particles using the core substance.

As a method for forming the above-described protrusions, there are a method in which a core substance is attached to the surface of the resin particle and then a conductive portion is formed by electroless plating, a method in which a conductive portion is formed by electroless plating on the surface of the resin particle and then a core substance is attached and a conductive portion is formed by electroless plating, and the like. Other methods for forming the protrusions include: a method of forming a first conductive portion on the surface of the resin particle, then disposing a core material on the first conductive portion, and then forming a second conductive portion; a method of adding a core material at an intermediate stage of forming a conductive portion (such as a first conductive portion or a second conductive portion) on the surface of the resin particle, and the like. And a method of forming a conductive portion by forming a conductive portion on the resin particle by electroless plating and then depositing a projection-like plating on the surface of the conductive portion without using the core material for forming the projection.

As a method of disposing the core substance on the surface of the above resin particle, for example, a method of adding the core substance to a dispersion of resin particles, and aggregating and attaching the core substance to the surface of the resin particle by van der waals force; and a method in which the core material is added to a container containing the resin particles, and the core material is adhered to the surfaces of the resin particles by a mechanical action such as rotation of the container. Since the amount of the attached core material is easily controlled, it is preferable that the core material is aggregated or attached to the surface of the resin particle in the dispersion.

The material of the above core substance is not particularly limited. As materials of the core material, there can be mentioned: a conductive substance and a non-conductive substance. Examples of the conductive material include: conductive nonmetal such as metal, metal oxide, and graphite, and conductive polymer. The conductive polymer may be polyacetylene or the like. Examples of the electrically nonconductive substance include: silica, alumina, barium titanate, zirconia, and the like. Since the conductivity can be improved and the connection resistance can be effectively reduced, a metal is preferable. The core material is preferably a metal particle. As the metal of the material of the core material, metals listed as the metals for forming the conductive portion can be suitably used.

Insulating material:

the conductive particles preferably include an insulating material provided on a surface of the conductive portion. In this case, when the conductive particles are used for connection between the electrodes, short-circuiting between adjacent electrodes can be further prevented. Specifically, when the plurality of conductive particles are in contact, an insulating substance is present between the plurality of electrodes, so that short-circuiting between adjacent electrodes in the lateral direction, not between the upper and lower electrodes, can be prevented. When the electrodes are electrically connected to each other, the conductive particles are pressurized by the two electrodes, and the insulating material between the conductive portions of the conductive particles and the electrodes can be easily removed. When the conductive particles have a plurality of protrusions on the outer surface of the conductive portion, the insulating material between the conductive portion of the conductive particles and the electrode can be removed more easily.

Since the insulating material can be more easily removed when the electrodes are pressed, the insulating material is preferably insulating particles.

Examples of the material of the insulating material include polyolefin compounds, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins, and water-soluble resins. The material of the insulating material may be used alone or in combination of two or more.

Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic ester copolymer. The (meth) acrylate polymer includes: polymethyl (meth) acrylate, polydodecyl (meth) acrylate, and polystearyl (meth) acrylate, and the like. Examples of the block polymer include: polystyrene, styrene-acrylate copolymers, SB type styrene-butadiene block copolymers, SBs type styrene-butadiene block copolymers, and hydrogenated products thereof, and the like. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include: epoxy resins, phenolic resins, melamine resins, and the like. The crosslinking of the thermoplastic resin may be carried out by introducing: polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, alkoxylated pentaerythritol methacrylate, and the like. Examples of the water-soluble resin include: polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, methyl cellulose, and the like. In addition, chain transfer agents may be used to regulate the degree of polymerization. Examples of the chain transfer agent include: mercaptans, carbon tetrachloride, and the like.

Examples of a method for providing an insulating substance on the surface of the conductive portion include a chemical method and a physical or mechanical method. As the chemical method, there may be mentioned: interfacial polymerization, suspension polymerization in the presence of particles, emulsion polymerization, and the like. Examples of the physical or mechanical methods include: spray drying, hybridization, electrostatic adhesion, spraying, dipping, vacuum evaporation, and the like. Since the insulating material is less likely to be detached, it is preferable that the insulating material is provided on the surface of the conductive portion by chemical bonding.

The outer surface of the conductive portion and the surface of the insulating material may be coated with a compound having a reactive functional group. The outer surface of the conductive portion and the surface of the insulating material may not be directly chemically bonded, but may be indirectly chemically bonded through a compound having a reactive functional group. After the carboxyl group is introduced to the outer surface of the conductive portion, the carboxyl group can be chemically bonded to a functional group on the surface of the insulating material via a polymer electrolyte such as polyethyleneimine.

(conductive Material)

The conductive material of the present invention includes the above conductive particles and a binder. The conductive particles are preferably dispersed in a binder and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The above-mentioned conductive material is preferably used for electrical connection between the electrodes. The above-mentioned conductive material is preferably a conductive material for circuit connection.

The adhesive is not particularly limited. As the adhesive, a known insulating resin is used. The binder preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. Examples of the curable component include a photocurable component and a thermosetting component. The photocurable component preferably contains a photocurable compound and a thermal polymerization initiator. The thermosetting component contains a thermosetting compound and a thermosetting agent.

Examples of the binder include: vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers, and the like. The above-mentioned binders may be used singly or in combination of two or more.

Examples of the vinyl resin include: vinyl acetate resins, acrylic resins, styrene resins, and the like. Examples of the thermoplastic resin include: polyolefin resins, ethylene-vinyl acetate copolymers, polyamide resins, and the like. Examples of the curable resin include: epoxy resins, polyurethane resins, polyimide resins, unsaturated polyester resins, and the like. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include: styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, hydrogenated products of styrene-butadiene-styrene block copolymers, hydrogenated products of styrene-isoprene-styrene block copolymers, and the like. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

The conductive material may contain, in addition to the conductive particles and the binder, for example: fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, UV absorbers, lubricants, antistatic agents, flame retardants, and the like.

The method for dispersing the conductive particles in the binder may be a conventionally known dispersion method, and is not particularly limited. Examples of the method for dispersing the conductive particles in the binder include: a method in which the conductive particles are added to the binder and then kneaded and dispersed with a planetary mixer or the like; a method in which the above conductive particles are uniformly dispersed in water or an organic solvent using a homogenizer or the like, and then added to the above binder, and kneaded and dispersed with a planetary mixer or the like. The method of dispersing the conductive particles in the binder includes a method of diluting the binder with water, an organic solvent, or the like, adding the conductive particles, and kneading and dispersing the mixture using a planetary mixer or the like.

The conductive material can be used as a conductive paste, a conductive film, and the like. When the conductive material is a conductive film, a film containing no conductive particles may be laminated on the conductive film containing conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

The content of the binder is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably 99.99% by weight or less, more preferably 99.9% by weight or less, of 100% by weight of the conductive material. When the content of the binder is not less than the lower limit and not more than the upper limit, the conductive particles are effectively provided between the electrodes, and the connection reliability of the connection target members connected by the conductive material is further improved.

The content of the conductive particles in 100 wt% of the conductive material is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, and preferably 80 wt% or less, more preferably 60 wt% or less, more preferably 40 wt% or less, particularly preferably 20 wt% or less, and most preferably 10 wt% or less. When the content of the conductive particles is not less than the upper limit and not less than the lower limit, the conduction reliability between the electrodes is further enhanced.

(Adhesives)

The adhesive of the present invention contains the above resin particles and an adhesive. The resin particles are preferably dispersed in an adhesive and used as the adhesive. The resin particles are preferably used as a spacer in an adhesive. The adhesive may contain no conductive particles.

The adhesive is used for forming an adhesive layer for bonding two members to be connected. The adhesive is used to control the gap of the adhesive layer with high accuracy or to relax the stress of the adhesive layer.

The adhesive is not particularly limited. Specific examples of the adhesive include adhesives used for the conductive material. The adhesive preferably contains an epoxy resin as the adhesive.

The content of the adhesive is preferably 10% by weight or more, more preferably 30% by weight or more, more preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably 99.99% by weight or less, more preferably 99.9% by weight or less, of 100% by weight of the adhesive. When the content of the adhesive is not less than the lower limit and not more than the upper limit, the adhesive strength of the adhesive layer can be further effectively improved, and the resin particles can further effectively function as spacers.

The content of the resin particles in 100 wt% of the adhesive is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, preferably 80 wt% or less, more preferably 60 wt% or less, more preferably 40 wt% or less, particularly preferably 20 wt% or less, and most preferably 10 wt% or less. When the content of the resin particles is not less than the lower limit and not more than the upper limit, the resin particles can more effectively function as a spacer.

(connection structure)

The connection structure can be obtained by connecting members to be connected using the conductive particles or a conductive material containing the conductive particles and a binder.

The connection structure of the present invention includes: the first connection target member has a first electrode on a surface thereof, the second connection target member has a second electrode on a surface thereof, and the connection portion connects the first connection target member and the second connection target member together. The material of the connecting part contains the resin particles. The material of the connecting portion is preferably the conductive particles or the conductive material. The connection portion is preferably a connection structure formed of the conductive particles or the conductive material.

When the conductive particles are used alone, the connecting portion itself is a conductive particle. That is, the first member to be connected and the second member to be connected are connected by the conductive particles. The conductive material used for obtaining the connection structure is preferably an anisotropic conductive material. Preferably, the first electrode and the second electrode are electrically connected by the connecting portion.

Fig. 4 is a cross-sectional view showing an example of a connection structure using the conductive particles 1 shown in fig. 1.

The connection structure 41 shown in fig. 4 includes a first connection object member 42, a second connection object member 43, and a connection portion 44 for connecting the first connection object member 42 and the second connection object member 43 together. The connection portion 44 is formed of a conductive material containing the conductive particles 1 and a binder. In fig. 4, the conductive particles 1 are schematically shown for convenience of explanation. Instead of the conductive particles 1, other conductive particles such as the conductive particles 21 and 31 may be used.

The first connection target member 42 has a plurality of first electrodes 42a on a surface (upper surface). The second connection target member 43 has a plurality of second electrodes 43a on a surface (lower surface). The first electrode 42a and the second electrode 43a are electrically connected by one or more conductive particles 1. Therefore, the first member to be connected 42 and the second member to be connected 43 are electrically connected by the conductive particles 1.

FIG. 5 is a sectional view showing an example of a connection structure using the resin particles of the present invention.

The connection structure 51 shown in fig. 5 includes an adhesive layer 54 that adheres together the first connection object member 52, the second connection object member 53, the first connection object member 52, and the second connection object member 53.

The adhesive layer 54 includes the resin particles 11 described above. The resin particles 11 do not contact the first connection target member 52 and the second connection target member 53. The resin particles 11 function as stress relaxation spacers.

The adhesive layer 54 includes gap-controlling particles 61 and a thermosetting component 62. In the adhesive layer 54, the gap control particles 61 are in contact with the first connection target member 52 and the second connection target member 53. The gap control particles 61 may be conductive particles or particles having no conductivity. The gap-controlling particles may be the resin particles. The thermosetting component 62 includes a thermosetting compound and a thermosetting agent. The thermosetting component 62 is a cured product of a thermosetting compound. The thermosetting component 62 is formed by curing a thermosetting compound.

The first connection target member may have a first electrode on a surface thereof. The second connection target member may have a second electrode on a surface thereof.

The method for producing the connection structure is not particularly limited. Examples of a method for manufacturing a connection structure include: a method of providing the conductive material between the first connection target member and the second connection target member to obtain a laminate, and then heating and pressing the laminate. The pressure at the time of the pressurization was 9.8X 10⁴Pa～4.9×10⁶Pa or so. The temperature during the heating is about 120-220 ℃. The pressure at the time of the above-mentioned pressing for connecting the electrode of the flexible printed board, the electrode provided on the resin film and the electrode of the touch panel was 9.8 × 10⁴Pa～1.0×10⁶Pa or so.

As the connection target member, specifically, there are mentioned: and electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as printed wiring boards, flexible printed boards, glass epoxy substrates, and glass substrate circuit boards. The connection object member is preferably an electronic member. Preferably, at least one of the first connection target member and the second connection target member is a semiconductor wafer or a semiconductor chip. The connection structure is preferably a semiconductor device.

The conductive material is preferably a conductive material for connecting electronic components. The conductive paste is a paste-like conductive material, and is preferably applied to the connection target member in a paste state.

The conductive particles, the conductive material, and the adhesive are suitably used for a touch panel. Therefore, the connection target member is preferably a connection target member in which a flexible substrate or an electrode is provided on a surface of a resin film. The member to be connected is preferably a flexible substrate, and is preferably a member to be connected in which an electrode is provided on a surface of a resin film. When the flexible substrate is a flexible printed circuit board or the like, the flexible substrate usually has an electrode on the surface.

Examples of the electrode provided in the connection target member include: metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, silver electrodes, SUS electrodes, copper electrodes, molybdenum electrodes, and tungsten electrodes. When the member to be connected is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, the electrode may be formed of aluminum alone or an aluminum layer may be laminated on the surface of the metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a metal element having a valence of 3, zinc oxide doped with a metal element having a valence of 3, and the like. Examples of the trivalent metal element include Sn, Al, and Ga.

(liquid Crystal display element)

The resin particles are suitably used as a spacer for a liquid crystal display element.

The liquid crystal display element of the present invention includes a first liquid crystal display element member, a second liquid crystal display element member, and a spacer provided between the first liquid crystal display element member and the second liquid crystal display element member. The spacer is the resin particle.

The liquid crystal display element may include a sealing portion that seals the outer peripheries of the first liquid crystal display element member and the second liquid crystal display element member in a state where the first liquid crystal display element member and the second liquid crystal display element member face each other.

The resin particles can be used for a periphery sealing agent for a liquid crystal display element. The liquid crystal display element includes a first liquid crystal display element member, a second liquid crystal display element member, and a sealing portion that seals the outer peripheries of the first liquid crystal display element member and the second liquid crystal display element member in a state where the first liquid crystal display element member and the second liquid crystal display element member face each other. The liquid crystal display element includes a liquid crystal disposed between the first liquid crystal display element member and the second liquid crystal display element member inside the sealing portion. In this liquid crystal display element, the sealing portion is formed by thermally curing a sealant used in the liquid crystal dropping method by using the liquid crystal dropping method.

Fig. 6 is a cross-sectional view showing an example of a liquid crystal display element using the resin particles of the present invention as spacers for the liquid crystal display element.

The liquid crystal display element 81 shown in fig. 6 has a pair of transparent glass substrates 82. The transparent glass substrate 82 has an insulating film (not shown) on the opposite surface. Examples of the material of the insulating film include: SiO 2₂And the like. The transparent electrode 83 is formed on the insulating film of the transparent glass substrate 82. As a material of the transparent electrode 83, ITO and the like can be cited. The transparent electrode 83 can be formed by patterning by, for example, photolithography. An alignment film 84 is formed on the transparent electrode 83 on the surface of the transparent glass substrate 82. As materials of the alignment film 84, there can be mentioned: polyimide, and the like.

The liquid crystal 85 is sealed between a pair of transparent glass substrates 82. The plurality of resin particles 11 are disposed between the pair of transparent glass substrates 82. The resin particles 11 function as spacers for a liquid crystal display element. The distance between the pair of transparent glass substrates 82 is limited by the plurality of resin particles 11. The sealant 86 is provided between the edge portions of the pair of transparent glass substrates 82. The sealant 86 prevents the liquid crystal 85 from flowing out to the outside. The sealing agent 86 includes only the resin particles 11A having a particle diameter different from that of the resin particles 11.

In the liquid crystal display element, 1mm²The arrangement density of the spacers for a liquid crystal display element is preferably 10/mm²Above, preferably 1000/mm²The following. The set density is 10 pieces/mm²In the above case, the cell gap is further uniform. The set density is 1000 pieces/mm²In the following, the contrast of the liquid crystal display element is further improved.

The present invention is specifically described below by way of examples and comparative examples. The present invention is not limited to the following examples.

(example 1)

(1) Preparation of resin particles

Polystyrene particles having an average particle diameter of 6.0 μm were prepared as seed particles. A mixed solution was prepared by mixing 5.0 parts by weight of the above polystyrene particles, 900 parts by weight of ion-exchanged water, and 170 parts by weight of a 5 wt% polyvinyl alcohol aqueous solution. The mixture was dispersed by ultrasonic waves, and then placed in a separable flask and stirred uniformly.

Further, cyclohexyl methacrylate was produced as the first polymerizable compound 1 having one polymerizable functional group and having a cyclic organic group, and isobornyl acrylate was produced as the first polymerizable compound 2 having one polymerizable functional group and having a cyclic organic group. Further, divinylbenzene is prepared as the second polymerizable compound having two or more polymerizable functional groups and having a cyclic organic group.

Then, 9 parts by weight of polytetramethylene glycol diacrylate, 1 part by weight of divinylbenzene, 15 parts by weight of cyclohexyl methacrylate and 75 parts by weight of isobornyl acrylate were mixed to obtain a mixture. To the resulting mixture was added 6.0 parts by weight of benzoyl peroxide ("Nyper BW" manufactured by nippon oil co., ltd.), and further 1000 parts by weight of ion-exchanged water was added to prepare an emulsion.

The emulsion was further added to the mixture in the separable flask, and the mixture was stirred for 16 hours to allow the seed particles to absorb the monomer, thereby obtaining a suspension containing the seed particles in which the monomer was swollen.

Then, 510 parts by weight of a 5% by weight aqueous polyvinyl alcohol solution was added, and heating was started to perform a reaction at 85 ℃ for 10 hours to obtain resin particles.

(2) Preparation of conductive particles

The obtained resin particles were washed and subjected to a classification operation, and then dried. Then, a nickel layer was formed on the surface of the obtained resin particle by an electroless plating method to prepare a conductive particle. The thickness of the nickel layer was 0.1. mu.m.

(3) Preparation of conductive Material (Anisotropic conductive paste)

To manufacture a conductive material (anisotropic conductive paste), the following materials were prepared.

(Material of conductive Material (Anisotropic conductive paste))

Thermosetting compound a: epoxy Compound (EP-3300P manufactured by Nagase ChemteX Corporation)

Thermosetting compound B: epoxy Compound (EPICLON HP-4032D manufactured by DIC corporation) thermosetting Compound C: epoxy Compound (Epogorsey PT, Polytetramethylene glycol diglycidyl ether, manufactured by synthetic Co., Ltd., Japan)

Thermal curing agent: thermal cation generator (Sansid "SI-60" manufactured by Sanxin chemical Co., Ltd.)

Filling: silicon dioxide (average particle diameter 0.25 μm)

The conductive material (anisotropic conductive paste) was produced as follows.

(method for producing conductive Material (Anisotropic conductive paste))

10 parts by weight of the thermosetting compound A, 10 parts by weight of the thermosetting compound B, 15 parts by weight of the thermosetting compound C, 5 parts by weight of the thermosetting agent and 20 parts by weight of the filler were mixed to obtain a mixture. And the resultant conductive particles were added so that the content in 100 wt% of the composition was 10 wt%, and then stirred at 2000rpm for 5 minutes using a planetary stirrer to obtain a conductive material (various conductive pastes).

(4) Preparation of connection Structure

As the first connection object member, a glass substrate having an aluminum electrode pattern with an L/S of 20 μm/20 μm on the upper surface was prepared. In addition, as a second connection target member, a semiconductor chip having a gold electrode pattern (gold electrode thickness 20 μm) of L/S of 20 μm/20 μm on the lower surface was prepared.

The conductive material (anisotropic conductive paste) just after the preparation was coated on the upper surface of the above glass substrate to a thickness of 30 μm to form a conductive material (anisotropic conductive paste) layer. Then, the semiconductor chip is stacked on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes face each other. Thereafter, the temperature of the head was adjusted so that the temperature of the conductive material (anisotropic conductive paste) layer became 170 ℃, and a pressure heating head was placed on the upper surface of the semiconductor chip, and the conductive material (anisotropic conductive paste) layer was cured under the conditions of 170 ℃, 1.0MPa, and 15 seconds to obtain a connection structure body.

(example 2)

In the preparation of the resin particles, 9 parts by weight of polytetramethylene glycol diacrylate was changed to 91 parts by weight of methyl methacrylate, the amount of cyclohexyl methacrylate was changed from 15 parts by weight to 5 parts by weight, and the amount of isobornyl acrylate was changed from 75 parts by weight to 3 parts by weight. Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except for the above-described variations.

(example 3)

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except that 9 parts by weight of polytetramethylene glycol diacrylate was changed to 9 parts by weight of 2-methacryloyloxyethyl acid phosphate in the preparation of resin particles.

(example 4)

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 2, except that 5 parts by weight of cyclohexyl methacrylate was changed to 5 parts by weight of phenoxyethylene glycol methacrylate when resin particles were prepared.

(example 5)

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 2, except that 5 parts by weight of cyclohexyl methacrylate was changed to 5 parts by weight of dicyclopentenyl acrylate when the resin particles were prepared.

(example 6)

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except that 1 part by weight of divinylbenzene was changed to 1 part by weight of tricyclodecane dimethanol diacrylate in the preparation of resin particles.

Comparative example 1

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except that the amount of polytetramethylene glycol diacrylate mixed was changed from 9 parts by weight to 10 parts by weight and divinylbenzene was not mixed in the preparation of the resin particles.

Comparative example 2

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except that 9 parts by weight of polytetramethylene glycol diacrylate was changed to 94 parts by weight of methyl methacrylate, the amount of cyclohexyl methacrylate was changed from 15 parts by weight to 5 parts by weight, and isobornyl acrylate was not mixed in the preparation of resin particles.

Comparative example 3

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in example 1, except that the amount of polytetramethylene glycol diacrylate mixed was changed from 9 parts by weight to 50 parts by weight and the amount of isobornyl acrylate mixed was changed from 75 parts by weight to 34 parts by weight when resin particles were prepared.

Comparative example 4

Conductive particles, a conductive material, and a connection structure were obtained in the same manner as in comparative example 1, except that 15 parts by weight of cyclohexyl methacrylate was changed to 15 parts by weight of phenoxyethylene glycol methacrylate when preparing resin particles.

(evaluation)

(1) A content (WM) of a structure derived from the first polymerizable compound and a content (WD) of a structure derived from the second polymerizable compound

The first polymerizable compound and the second polymerizable compound which have been polymerized are obtained from the amount of the first polymerizable compound and the second polymerizable compound to be mixed for obtaining a polymer and the remaining amounts of the first polymerizable compound and the second polymerizable compound after polymerization, and the content (WM) of the structure derived from the first polymerizable compound and the content (WD) of the structure derived from the second polymerizable compound in the obtained resin particles are calculated. The weight ratio (WM/WD) of the content (WM) of the structure from the first polymerizable compound to the content (WD) of the structure from the second polymerizable compound was calculated.

(2) Particle size

The particle diameter (particle diameter before heating) of the obtained resin particles was measured using a particle diameter distribution measuring apparatus ("Multisizer 4" manufactured by Beckman Coulter corporation), and the particle diameter of 100000 resin particles was measured and the average value was calculated.

Then, the resin particles for measuring the particle diameter were heated at 150 ℃ for 1000 hours. The particle diameter of the resin particles after heating for 1000 hours was measured by the above method. From the obtained measurement results, the ratio of the particle diameter of the resin particles after heating to the particle diameter of the resin particles before heating (particle diameter of the resin particles after heating/particle diameter of the resin particles before heating) was calculated.

(3) 10% K value and 30% K value

The 10% K value and 30% K value (30% K value before heating) of the obtained resin particles were measured by the above-mentioned methods.

Then, the resin particles for measuring a 30% K value were heated at 150 ℃ for 1000 hours. The 30% K value of the resin particles after heating for 1000 hours was measured by the above method. From the obtained measurement results, the ratio of the 30% K value after heating to the 30% K value before heating (30% K value after heating/30% K value before heating) was calculated.

(4) Compression recovery rate at 60% compression set

The compression recovery rate of the obtained resin particles subjected to 60% compression deformation was measured by the above-mentioned method.

(5) State of plating

The obtained conductive particles were heated at 150 ℃ for 1000 hours. The plating state of 50 heated conductive particles was observed by a scanning electron microscope. The plating layer was evaluated for the presence of plating unevenness such as plating layer cracking and plating layer peeling. The plating state was judged according to the following criteria.

[ determination criteria for plating State ]

O ^ O: less than 3 conductive particles with plating unevenness were confirmed

O: the number of the conductive particles having non-uniform plating was found to be 3 or more and less than 6

X: the number of the conductive particles for which plating unevenness was observed was 6 or more

(6) Strength of connection

The connection strength of the obtained connection structure at 260 ℃ was measured using a mounting strength measuring device. The connection strength was determined according to the following criteria.

[ criteria for judging connection Strength ]

O ^ O: the shear strength is 150N/cm²The above

O: the shear strength is 100N/cm²Above and less than 150N/cm²

X: the shear strength is less than 100N/cm²

(7) Rebound resilience

Whether or not springback occurred at the joint portion of the obtained connection structure was observed using a scanning electron microscope. Springback was judged according to the following criteria.

[ criteria for determining rebound ]

O: no rebound occurs

X: occurrence of rebound

(8) Thermal cycling characteristics (reliability of connection)

The following cold-hot cycle test was performed 1000 times, which set the process of heating the obtained connection structure from-65 ℃ to 150 ℃ and cooling to-65 ℃ as one cycle. The occurrence of floating or peeling on the connection portion was observed using an ultrasonic flaw detector (SAT). The thermal cycle characteristics (connection reliability) were judged based on the following criteria.

[ criterion for judging Cold-Heat cycle characteristics (connection reliability) ]

O: no floating or peeling of the connecting part

X: floating or peeling of the connection

The results are shown in tables 1, 2, 3 below.

(9) Use example of spacer for liquid crystal display element

Preparation of STN type liquid crystal display element:

the spacers (resin particles) for liquid crystal display elements of examples 1 to 6 were added to a dispersion medium containing 70 parts by weight of isopropyl alcohol and 30 parts by weight of water so that the solid content concentration in 100% by weight of the obtained spacer dispersion was 2% by weight, and the mixture was stirred to obtain a spacer dispersion for liquid crystal display elements.

SiO was vapor-deposited by a CVD method on one surface of a pair of transparent glass plates (50 mm in length, 50mm in width, and 0.4mm in thickness)₂Film, then, by sputtering on SiO₂An ITO film is formed on the entirety of the film surface. On the glass substrate to which the obtained ITO film was attached, a polyimide alignment film composition (manufactured by nippon chemical co., ltd., SE3510) was applied by a spin coating method and fired at 280 ℃ for 90 minutes to form a polyimide alignment film. After rubbing the alignment film, spacers for liquid crystal display element were wet-dispersed on the alignment film side of one substrate so as to be 1mm²There are 100 of them. After a sealant was formed around the other substrate, the substrate and the substrate with the spacers dispersed therein were opposed to each other, and the substrates were bonded to each other with the rubbing direction set to 90 °. Then, the sealant was cured by treatment at 160 ℃ for 90 minutes to obtain an empty cell (screen without liquid crystal). An STN type liquid crystal (manufactured by DIC corporation) containing a chiral agent was injected into the obtained empty cell, and then the entrance was closed with a sealant and heat-treated at 120 ℃ for 30 minutes to obtain an STN liquid crystal display element.

In the obtained liquid crystal display devices, the spacers (resin particles) for liquid crystal display devices in examples 1 to 6 favorably regulated the gap between the substrates. In addition, the liquid crystal display element exhibits good display quality. When the resin particles of examples 1 to 6 were used as spacers for liquid crystal display elements, the obtained liquid crystal display elements had good display quality.

Description of the symbols

Conductive particles

An electrically conductive part

Resin particles

Resin particles

Conductive particles

An electrically conductive portion

A first conductive portion

A second conductive portion

Conductive particles

A projection

A conductive portion

A projection

Core material

An insulating material

Connecting structure

A first connection object component

A first electrode

A second connection object part

43a second electrode

A connecting part

A connection structure

A first connection subject component

53.. second connection object part

An adhesive layer

61.. gap control particles

A thermosetting composition

An 81

82.. transparent glass substrate

A transparent electrode

An alignment film

85.. liquid crystal

86.. sealant