JP6333626B2 - Projection particle, conductive particle, conductive material, and connection structure - Google Patents

Description

  The present invention relates to a projecting particle comprising a core particle and an inorganic shell disposed on the surface of the core particle. The present invention also relates to conductive particles, conductive materials, and connection structures using the protruding particles.

  Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin. The anisotropic conductive material is used to electrically connect 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. ing. Moreover, as the conductive particles, conductive particles having base particles and a conductive layer disposed on the surface of the base particles may be used.

As an example of the base material particles used for the conductive particles, the following Patent Document 1 discloses silica particles (projection particles) having protrusions bonded to the entire surface of the base particles by chemical bonds. ing. The protrusions are substantially spherical or crown-shaped. In Patent Document 1, specifically, in the silica particle, both the base particle and the protrusion are derived from an alkoxysilane represented by the formula: R ¹ _n Si (OR ² ) _4-n. It is described as having a composition. Patent Document 1 also discloses conductive particles having the silica particles and a conductive coating layer formed on the surface of the silica particles.

  In the following Patent Document 2, the step (I) of obtaining a polymerizable organopolysiloxane particle (S1) by hydrolyzing and condensing a silicon compound group containing a hydrolyzable silicon compound having a polymerizable organic group as an essential component, A step (II) of obtaining the organic-inorganic composite particles (P1) by polymerizing the polymerizable organopolysiloxane particles (S1), and adding a polymerizable monomer (M1) to the organic-inorganic composite particles (P1) A core-shell type organic comprising a step (III) of obtaining inorganic composite particles (P2) and a step (IV) of polymerizing the organic-inorganic composite particles (P2) to obtain core-shell type organic-inorganic composite particles (P3) Organic-inorganic composite particles obtained by a method for producing inorganic composite particles are disclosed.

  In Patent Document 3 below, as an example of the conductive particles, a conductive material in which a nickel or nickel alloy film is formed by electroless plating on the surface of spherical core particles having an average particle diameter of 1 to 20 μm. Particles are disclosed. The conductive particles have minute protrusions of 0.05 to 4 μm on the outermost surface of the film, and in the conductive particles, the film and the minute protrusions are substantially continuous films.

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

  As an example of the particles used for the spacer for the liquid crystal display element, the following Patent Document 4 has a core particle and a single-layer or multilayer thermoplastic resin film formed on the surface of the core particle. A protruding particle having a protrusion on the surface is disclosed. The thermoplastic resin film is a film formed by precipitation polymerization.

Japanese Patent Laid-Open No. 2003-212534 JP 2010-229303 A JP 2000-243132 A JP 2003-192939 A

  In the protruding particles described in Patent Document 1, the strength of the protrusion is low, and the protrusion may be easily detached.

  The organic-inorganic composite particles described in Patent Document 2 do not have protrusions on the outer surface.

  In the conductive particles described in Patent Document 3, protrusions are formed on the nickel or nickel alloy film. However, the spherical core particles coated with the nickel or nickel alloy film do not have protrusions on the surface.

  Even with the protruding particles described in Patent Document 4, the strength of the protrusion is low, and the protrusion may be easily detached. Moreover, in patent document 4, the thermoplastic resin film using a thermoplastic resin is only formed on the surface of a core particle.

  An object of the present invention is to provide a protruding particle that has a high protrusion strength and can prevent the protrusion from coming off, and to provide a conductive particle, a conductive material, and a connection structure using the protruding particle. is there.

  According to a wide aspect of the present invention, a core particle and an inorganic shell disposed on a surface of the core particle are provided, the inorganic shell has a plurality of protrusions on an outer surface, and the inorganic shell is a silane alkoxide. In the total number of 100% of silicon atoms contained in the inorganic shell, four —O—Si groups are directly bonded and four oxygen atoms in the four —O—Si groups Protrusion particles are provided in which the proportion of the number of silicon atoms to which is directly bonded is 50% or more.

  On the specific situation with the protrusion particle | grains which concern on this invention, the said inorganic shell is formed so that it may have a some protrusion on an outer surface by the sol-gel method using a silane alkoxide.

  On the specific situation with the protrusion particle | grains which concern on this invention, the height of the said protrusion is 50 nm or more and 500 nm or less.

  In a specific aspect of the protruding particle according to the present invention, the core particle is an organic core particle.

  In a specific aspect of the protruding particle according to the present invention, the inorganic shell has a first inorganic shell portion, and a plurality of protrusions on the outer surface of the inorganic shell, the thickness being thicker than the first inorganic shell portion. A second inorganic shell portion that is formed, and the first inorganic shell portion and the second inorganic shell portion are connected to each other.

  The protruding particles according to the present invention are preferably used for obtaining conductive particles having a conductive layer formed on the surface thereof and having the conductive layer, or used as spacers for liquid crystal display elements.

  According to a wide aspect of the present invention, there is provided a conductive particle comprising the above-mentioned protruding particle and a conductive layer disposed on the surface of the protruding particle and having a plurality of protrusions on the outer surface.

  According to a wide aspect of the present invention, the conductive particles include conductive particles and a binder resin, the conductive particles are disposed on the surface of the above-described protruding particles and the protruding particles, and a plurality of outer surfaces are disposed on the outer surface. A conductive material is provided comprising a conductive layer having a protrusion.

  According to a wide aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the A connection portion connecting the second connection target member, and the connection portion is formed of conductive particles or formed of a conductive material including the conductive particles and a binder resin. The conductive particles include the above-described protruding particles, and a conductive layer disposed on the surface of the protruding particles and having a plurality of protrusions on the outer surface, and the first electrode and the second electrode A connection structure is provided in which an electrode is electrically connected by the conductive particles.

  The protruding particle according to the present invention includes a core particle and an inorganic shell disposed on the surface of the core particle, the inorganic shell has a plurality of protrusions on the outer surface, and the inorganic shell is made of silane alkoxide. In the 100% total number of silicon atoms contained in the inorganic shell, four —O—Si groups are directly bonded, and four oxygen atoms in the four —O—Si groups are Since the ratio of the number of silicon atoms directly bonded is 50% or more, the strength of the protrusion can be increased and the protrusion can be suppressed.

FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles according to the second embodiment of the present invention. FIG. 3 is a front cross-sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a liquid crystal display element using the protruding particles according to one embodiment of the present invention as a spacer for a liquid crystal display element.

  Hereinafter, the present invention will be described in detail.

(Projection particles)
The protruding particle according to the present invention includes a core particle and an inorganic shell disposed on the surface of the core particle. The inorganic shell has a plurality of protrusions on the outer surface. The inorganic shell is made of silane alkoxide. In 100% of the total number of silicon atoms contained in the inorganic shell, four —O—Si groups are directly bonded, and four oxygen atoms in the four —O—Si groups are directly bonded. The ratio of the number of silicon atoms is 50% or more.

  Since the protrusion particle | grains which concern on this invention are provided with the structure mentioned above, the intensity | strength of protrusion can be made high and it can suppress that protrusion protrudes excessively. If the ratio of the number of silicon atoms is 50% or more, the protrusions are considerably less likely to come off than when the ratio of the number of silicon atoms is less than 50%.

  For example, when the protruding particles are used as a spacer for a liquid crystal display element, in the liquid crystal display element to be obtained, protrusions (inorganic shell fragments) that are separated from the spacer for the liquid crystal display element are hardly included in the liquid crystal, and the obtained liquid crystal The display quality of the display element can be further improved.

  When a conductive layer is formed on the surface of the protruding particle to obtain a conductive particle, the strength of the protrusion of the conductive layer is increased, so that the electrodes are electrically connected using the obtained conductive particle. In this case, the electrode and the conductive layer can be more reliably brought into contact with each other. Further, when an oxide film is formed on the surface of the conductive layer and the surface of the electrode, the oxide film is effectively excluded due to the protrusions of the inorganic shell. For this reason, an electrode and the conductive layer of electroconductive particle can be contacted still more reliably, and the connection resistance between electrodes can be made low. Furthermore, when the conductive particles have an insulating material on the surface, or when the conductive particles are dispersed in a binder resin and used as a conductive material, the conductive particles are derived from the protrusions of the inorganic shell, An insulating material or binder resin between the electrodes can be effectively eliminated. For this reason, the conduction | electrical_connection reliability between electrodes can be improved.

  The application of the protruding particles is not particularly limited. The protruding particles are suitably used for various applications. The protruding particles are preferably used to obtain conductive particles having a conductive layer formed on the surface and having the conductive layer, or used as spacers for liquid crystal display elements. The protruding particles are preferably used for obtaining conductive particles having a conductive layer formed on the surface and having the conductive layer. The protruding particles are preferably used as a spacer for a liquid crystal display element.

  Furthermore, the protruding particles are also suitably used as an inorganic filler, a toner additive, a shock absorber or a vibration absorber. For example, the protruding particles can be used as a substitute for rubber or a spring.

  In order to form protrusions using silane alkoxide, it is preferable to use a sol-gel method. The inorganic shell is preferably formed using a silane alkoxide so as to have a plurality of protrusions on the outer surface by a sol-gel method.

  The height of the protrusion is preferably 10 nm or more, preferably 1000 nm or less, more preferably 500 nm or less. The height of the protrusion is more preferably 50 nm or more and 500 nm or less. The height of the protrusion is more preferably 50 nm or more and 200 nm or less. When the height of the protrusion is equal to or more than the lower limit, the effect due to the presence of the protrusion can be obtained more effectively than in the case where there is no protrusion. When the height of the protrusion is not more than the above upper limit, the protrusion is more difficult to come off.

  The height of the protrusion is an average of the heights of the plurality of protrusions in the protrusion particle. The height of the protrusion can be obtained by measuring the maximum height of the raised height of the inorganic shell portion with one protrusion, based on the inorganic shell portion without the protrusion. The height of the protrusion can be confirmed with a scanning electron microscope.

  The number of the protrusions is preferably 10 or more, more preferably 50 or more, and still more preferably 90 or more on the surface of one protrusion particle. The number of the protrusions can be confirmed with a scanning electron microscope.

  The shape of the protrusion is not particularly limited. Examples of the shape of the protrusion include a part of a sphere, a part of a spheroid, a cone, a cylinder, a pyramid, and a prism.

  The inorganic shell has a first inorganic shell portion and a second inorganic shell portion that is thicker than the first inorganic shell portion and has a plurality of protrusions formed on the outer surface of the inorganic shell. The first inorganic shell portion and the second inorganic shell portion are preferably continuous. In this case, it is possible to further suppress the protrusion from coming off.

  The ratio of the thickness of the inorganic shell to the radius of the core particle (the thickness of the inorganic shell / the radius of the core particle) is preferably 0.05 or more, more preferably 0.1 or more, still more preferably 0.15 or more, preferably Is 0.7 or less, more preferably 0.65 or less, and still more preferably 0.6 or less. When the ratio is not less than the above lower limit and not more than the above upper limit, the 10% K value of the protruding particles can be sufficiently increased, the connection resistance between the electrodes can be decreased, and the insulation reliability can be increased. it can.

The compression elastic modulus (10% K value) when the protruding particles are 10% compressively deformed is preferably 2000 N / mm ² or more, more preferably 3000 N / mm ² or more, still more preferably 4000 mN / mm ² or more, particularly preferably. the 5000N / mm ² or more, and most preferably 6000 N / mm ² or more, preferably 15000 N / mm ² or less, more preferably 10000 N / mm ^2, more preferably not more than 8500N / mm ^2. The protruding particles having the 10% K value of not less than the above lower limit and not more than the above upper limit have good compression deformation characteristics. The 10% K value may be 50000 N / mm ² or less.

The compression modulus upon 30% compression deformation of the projection particles (30% K value) is preferably 300N / mm ² or more, more preferably 600N / mm ² or more, more preferably 800 N / mm ² or more, particularly preferably it is 1000 N / mm ² or more, preferably 5000N / mm ² or less, more preferably 4500N / mm ^2, more preferably not more than 4000 N / mm ^2. The protruding particles having the 30% K value of not less than the above lower limit and not more than the above upper limit have good compression deformation characteristics.

  Since good compression deformation characteristics can be obtained, the compression elastic modulus (10% K value) when the protruding particles are compressed by 10%, and the compression elastic modulus (30% K value) when the protruding particles are compressed by 30%. ) (10% K value / 30% K value) is preferably 1 or more, more preferably 1.3 or more, still more preferably 1.8 or more, particularly preferably 2.0 or more, preferably 10.0 or less. More preferably, it is 5.0 or less, More preferably, it is 4.4 or less.

  The compression elastic modulus (10% K value and 30% K value) of the protruding particles can be measured as follows.

  Using a micro-compression tester, the projecting particles are compressed under the conditions of a cylindrical indenter (diameter: 100 μm, made of diamond) and a smooth indenter at 25 ° C., a compression rate of 0.3 mN / sec, and a maximum test load of 20 mN. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression elastic modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value (N) when the protruding particles are 10% or 30% compressively deformed
S: Compression displacement (mm) when the protruding particles are 10% or 30% compressively deformed
R: Radius of projection particle (mm)

  The compression elastic modulus universally and quantitatively represents the hardness of the protruding particles. By using the compression modulus, the hardness of the protruding particles can be expressed quantitatively and uniquely.

  In 100% by weight of the core particles, the content of silicon atoms contained in the core particles is preferably 10% by weight or less, more preferably 5% by weight or less. The core particles may not contain silicon atoms. The core particles preferably do not contain silicon atoms. In 100% by weight of the core particles, the content of carbon atoms contained in the core particles is preferably 50% by weight or more, more preferably 60% by weight or more, and still more preferably 65% by weight or more. The lower the silicon atom content in the core particle and the higher the carbon atom content in the core particle, the higher the flexibility of the protruding particle itself derived from the core particle, even if the protrusion is hard. .

  In 100% by weight of the inorganic shell, the content of silicon atoms contained in the inorganic shell is preferably 50% by weight or more, more preferably 54% by weight or more, and further preferably 56% by weight or more. In 100% by weight of the inorganic shell, the content of carbon atoms contained in the inorganic shell is preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 10% by weight or less. The inorganic shell preferably does not contain carbon atoms. The higher the silicon atom content in the inorganic shell and the lower the carbon atom content in the inorganic shell, the better the hardness at the initial compression due to the inorganic shell.

  Content of the silicon atom and the carbon atom in the core particle and the inorganic shell in the protruding particle can be measured by a line analysis by a TEM / EDS method.

  Examples of the core particles include inorganic core particles excluding metal core particles, organic core particles, and metal core particles. The core particles are preferably core particles excluding metal core particles, and are preferably inorganic core particles or organic core particles excluding metal core particles.

  The core particles are preferably organic core particles. By using the organic core particles, even when the protrusions are hard, the protrusion particles themselves are more flexible due to the core particles. Furthermore, the connection resistance between the electrodes connected by the conductive particles is further reduced, and the display quality of the liquid crystal display element using the liquid crystal display element spacer is further improved.

  Various organic materials are suitably used as a material for forming the organic core particles. Examples of materials for forming the organic core particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Polymerize one or more of alkylene terephthalate, polysulfone, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, and various polymerizable monomers having ethylenically unsaturated groups. The polymer obtained by the above is used. Since the flexibility becomes even higher, the organic core particle is formed by polymerizing the monomer having an ethylenically unsaturated group using the monomer having an ethylenically unsaturated group. It is preferable. By polymerizing one or more of various polymerizable monomers having an ethylenically unsaturated group, it is easy to design and synthesize protruding particles having any compression property suitable for conductive materials. is there.

  When the organic core particle is obtained by polymerizing a monomer having an ethylenically unsaturated group, the monomer having the ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. Monomer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylates such as meth) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate Esters; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene Is mentioned.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanure And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane It is done.

  The organic core particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  From the viewpoint of suppressing deformation of the core particles during the formation of the inorganic shell and the use of the protruding particles, the decomposition temperature of the core particles is preferably more than 200 ° C, more preferably more than 250 ° C, and even more preferably 300. Over ℃. The decomposition temperature of the core particles may exceed 400 ° C., may exceed 500 ° C., may exceed 600 ° C., and may exceed 800 ° C.

  The aspect ratio of the core particles is preferably 2 or less, more preferably 1.5 or less, and still more preferably 1.2 or less. The aspect ratio indicates a major axis / minor axis.

  The particle diameter of the core particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. is there. When the particle diameter of the core particle is not less than the above lower limit and not more than the above upper limit, the 10% K value and the 30% K value show even more suitable values, and the projection particles are used as conductive particles and spacers for liquid crystal display elements. Can be suitably used. For example, when the particle diameter of the core 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 electrode is sufficiently large, And it becomes difficult to form the agglomerated conductive particles when forming the conductive layer. Further, the interval between the electrodes connected via the conductive particles does not become too large, and the conductive layer is difficult to peel from the surface of the protruding particles.

  The particle diameter of the core particle means a diameter when the core particle is a true sphere, and means a maximum diameter when the core particle is a shape other than a true sphere. Moreover, in this invention, a particle size means the average value which observed the core particle using the scanning electron microscope, and measured the particle size of 50 core particles selected arbitrarily with a caliper.

  The protruding particles are core-shell particles. The inorganic shell is disposed on the surface of the core particle. The inorganic shell preferably covers the surface of the core particle.

  The inorganic shell is preferably formed on the surface of the core particle by making silane alkoxide into a shell-like material by a sol-gel method and then firing the shell-like material. In the sol-gel method, it is easy to dispose a shell-like material on the surface of the core particle. When the firing is performed, in the projecting particles, after the firing, the core particles remain without being removed by volatilization or the like. The protruding particles include the core particles after firing. If the core particles are removed by volatilization or the like after firing, the 10% K value becomes considerably low.

  As a specific method of the sol-gel method, an interfacial sol is prepared by coexisting a silane alkoxide in a dispersion containing core particles, a solvent such as water, alcohol and aprotic, a surfactant, and a catalyst such as an aqueous ammonia solution. Examples include a method of performing a reaction and a method of heteroaggregating a sol-gel reactant on core particles after performing a sol-gel reaction with a silane alkoxide coexisting with water, an alcohol-based or aprotic solvent, and an aqueous ammonia solution. . In the sol-gel method, the silane alkoxide is preferably hydrolyzed and polycondensed.

  In the sol-gel method, it is preferable to use a surfactant. In the presence of a surfactant, the silane alkoxide is preferably made into a shell by a sol-gel method. The surfactant is not particularly limited. The surfactant is appropriately selected and used so as to form a good shell. Examples of the surfactant include a cationic surfactant, an anionic surfactant, and a nonionic surfactant. Among these, a cationic surfactant is preferable because a good inorganic shell can be formed.

  Examples of the cationic surfactant include quaternary ammonium salts and quaternary phosphonium salts. Specific examples of the cationic surfactant include hexadecyl ammonium bromide.

  In order to form the inorganic shell on the surface of the core particle, the shell-like material is preferably fired. The degree of crosslinking in the inorganic shell can be adjusted by the firing conditions. In addition, by performing the firing, the 10% K value and the 30% K value of the above-mentioned protruding particles show even more suitable values as compared with the case where the firing is not performed. In particular, the 10% K value can be sufficiently increased by increasing the degree of crosslinking.

  The inorganic shell is preferably formed by forming a silane alkoxide into a shell-like material by a sol-gel method on the surface of the core particle and then firing the shell-like material at 100 ° C. or higher (firing temperature). . The firing temperature is more preferably 150 ° C. or higher, and further preferably 200 ° C. or higher. When the firing temperature is equal to or higher than the lower limit, the degree of crosslinking in the inorganic shell becomes more appropriate, and the 10% K value and the 30% K value show even more suitable values. It can be used more suitably depending on the use of the element spacer.

  The inorganic shell is formed on the surface of the core particle by making silane alkoxide into a shell-like material by a sol-gel method and then firing the shell-like material at a temperature lower than the decomposition temperature (firing temperature) of the core particle. Preferably it is. The firing temperature is preferably 5 ° C. or more lower than the decomposition temperature of the core particles, and more preferably 10 ° C. or more lower than the decomposition temperature of the core particles. Moreover, the said calcination temperature becomes like this. Preferably it is 800 degrees C or less, More preferably, it is 600 degrees C or less, More preferably, it is 500 degrees C or less. When the calcination temperature is not more than the above upper limit, thermal deterioration and deformation of the core particles can be suppressed, and protruding particles exhibiting favorable values of 10% K value and 30% K value are obtained.

  Silane alkoxides are used to form a good inorganic shell. As for the said silane alkoxide, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of forming a good inorganic shell, the silane alkoxide is preferably a silane alkoxide represented by the following formula (1A).

Si (R1) _n (OR2) _4-n Formula (1A)

  In the above formula (1A), R1 represents a phenyl group, an alkyl group having 1 to 30 carbon atoms, an organic group having 1 to 30 carbon atoms having a polymerizable double bond, or an organic group having 1 to 30 carbon atoms having an epoxy group. R2 represents an alkyl group having 1 to 6 carbon atoms, and n represents an integer of 0 to 2. When n is 2, the plurality of R1s may be the same or different. Several R2 may be the same and may differ. In order to effectively increase the content of silicon atoms contained in the inorganic shell, n in the above formula (1A) preferably represents 0 or 1, and more preferably represents 0. When the content of silicon atoms contained in the inorganic shell is high, the effect of the present invention is more excellent.

  When R1 is an alkyl group having 1 to 30 carbon atoms, specific examples of R1 include methyl group, ethyl group, propyl group, isopropyl group, isobutyl group, n-hexyl group, cyclohexyl group, n-octyl group, And n-decyl group. This alkyl group preferably has 10 or less carbon atoms, more preferably 6 or less. The alkyl group includes a cycloalkyl group.

  Examples of the polymerizable double bond include a carbon-carbon double bond. When R1 is an organic group having 1 to 30 carbon atoms having a polymerizable double bond, specific examples of R1 include a vinyl group, an allyl group, an isopropenyl group, and a 3- (meth) acryloxyalkyl group. Etc. Examples of the (meth) acryloxyalkyl group include a (meth) acryloxymethyl group, a (meth) acryloxyethyl group, and a (meth) acryloxypropyl group. The carbon number of the organic group having 1 to 30 carbon atoms having a polymerizable double bond is preferably 2 or more, preferably 30 or less, more preferably 10 or less. The above “(meth) acryloxy” means methacryloxy or acryloxy.

  When R1 is an organic group having 1 to 30 carbon atoms having an epoxy group, specific examples of R1 include 1,2-epoxyethyl group, 1,2-epoxypropyl group, 2,3-epoxypropyl group, Examples include 3,4-epoxybutyl group, 3-glycidoxypropyl group, and 2- (3,4-epoxycyclohexyl) ethyl group. The carbon number of the C1-C30 organic group having the epoxy group is preferably 8 or less, more preferably 6 or less. In addition, the C1-C30 organic group which has the said epoxy group is group containing the oxygen atom derived from an epoxy group in addition to a carbon atom and a hydrogen atom.

  Specific examples of R2 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. In order to effectively increase the content of silicon atoms contained in the inorganic shell, R2 preferably represents a methyl group or an ethyl group.

  Specific examples of the silane alkoxide include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxy. Examples include silane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, and diisopropyldimethoxysilane. Silane alkoxides other than these may be used.

  In order to effectively increase the content of silicon atoms contained in the inorganic shell, it is preferable to use tetramethoxysilane or tetraethoxysilane as the material of the inorganic shell. In 100% by weight of the inorganic shell material, the total content of tetramethoxysilane and tetraethoxysilane is preferably 50% by weight or more (or the total amount may be sufficient). In 100% by weight of the inorganic shell, the total content of the skeleton derived from tetramethoxysilane and the skeleton derived from tetraethoxysilane is preferably 50% by weight or more (or the total amount may be sufficient).

  The silane alkoxide preferably includes a silane alkoxide having a structure in which four oxygen atoms are directly bonded to a silicon atom. The silane alkoxide preferably includes a silane alkoxide represented by the following formula (1Aa).

Si (OR2) ₄ Formula (1Aa)

  In said formula (1Aa), R2 represents a C1-C6 alkyl group. Several R2 may be the same and may differ.

  Each of the silane alkoxide having a structure in which four oxygen atoms are directly bonded to the silicon atom, or the silane alkoxide represented by the formula (1Aa) in 100 mol% of the silane alkoxide used for forming the inorganic shell. The content is preferably 20 mol% or more, more preferably 40 mol% or more, still more preferably 50 mol% or more, still more preferably 55 mol% or more, particularly preferably 60 mol% or more and 100 mol% or less. . The total amount of the silane alkoxide used to form the inorganic shell is a silane alkoxide having a structure in which four oxygen atoms are directly bonded to the silicon atom, or a silane alkoxide represented by the formula (1Aa). Also good.

  From the viewpoint of effectively increasing the 10% K value and effectively decreasing the 30% K value, four —O— in 100% of the total number of silicon atoms contained in the inorganic shell. The ratio of the number of silicon atoms in which the Si group is directly bonded and the four oxygen atoms in the four —O—Si groups are directly bonded is preferably 20% or more, more preferably 40% or more. Preferably it is 50% or more, More preferably, it is 55% or more, Most preferably, it is 60% or more. On the other hand, in order to increase the strength of the protrusions and suppress the protrusions from being removed, the number of silicon atoms in which four oxygen atoms are directly bonded in 100% of the total number of silicon atoms contained in the inorganic shell. The ratio is 50% or more.

  Note that a silicon atom in which four —O—Si groups are directly bonded and four oxygen atoms in the four —O—Si groups are directly bonded is represented by, for example, the following formula (11). It is a silicon atom in the structure. Specifically, it is a silicon atom indicated by an arrow A in the structure represented by the following formula (11X).

  The oxygen atom in the above formula (11) generally forms a siloxane bond with the adjacent silicon atom.

  The ratio of the number of silicon atoms in which four -O-Si groups are directly bonded and the four oxygen atoms in the four -O-Si groups are directly bonded (the ratio of the number of Q4 (%)). As a measuring method, for example, using an NMR spectrum analyzer, Q4 (four -O-Si groups are directly bonded and four oxygen atoms in the four -O-Si groups are directly bonded). The peak area of silicon atoms) and Q1 to Q3 (1 to 3 —O—Si groups are directly bonded, and 1 to 3 oxygen atoms in 1 to 3 —O—Si groups are directly bonded to each other. And the peak area of silicon atoms). By this method, in the total number of 100% of silicon atoms contained in the inorganic shell, four —O—Si groups are directly bonded, and four oxygen atoms in the four —O—Si groups are directly bonded. The ratio of the number of bonded silicon atoms (the ratio of the number of Q4) can be determined. In addition, in the NMR measurement result which calculated | required the ratio of the number of Q4 of the Example mentioned later, four -O-Si groups are couple | bonded directly and the four oxygen atoms in the said four -O-Si group are couple | bonded directly. The peak derived from the silicon atom is evaluated.

  The thickness of the inorganic shell is preferably 10 nm or more, more preferably 50 nm or more, particularly preferably 100 nm or more, preferably 100,000 nm or less, more preferably 10,000 nm or less, and still more preferably 2000 nm or less. When the thickness of the inorganic shell is not less than the above lower limit and not more than the above upper limit, the 10% K value and the 30% K value show even more suitable values, and the protruding particles are used for conductive particles and spacers for liquid crystal display elements. It becomes possible to use suitably. The thickness of the inorganic shell is an average thickness per protruding particle. The thickness of the inorganic shell can be controlled by controlling the sol-gel method.

  Regarding the method of forming the portion excluding the protrusion of the inorganic shell and the protrusion of the inorganic shell, a catalyst such as an excessive amount of aqueous ammonia solution is formed on the surface of the core particle while forming a silane alkoxide into a shell-like material by a sol-gel method. As appropriate, the portion excluding the protrusion of the inorganic shell and the protrusion of the inorganic shell can be formed simultaneously in a single step.

  In the present invention, the thickness of the inorganic shell is determined by observing the protruding particles with a scanning electron microscope and measuring the average particle size of 50 arbitrarily selected protruding particles with a caliper, and the particle size of the core particles. It can be obtained from the difference from the average value. The particle diameter of the protruding particles means the diameter when the protruding particles are spherical, and means the maximum diameter when the protruding particles have a shape other than the spherical shape.

  It is preferable that there is no chemical bond between the core particle and the inorganic shell. In the case where the core particles and the inorganic shell are not chemically bonded, the inorganic shell is not easily cracked, and the contact area of the electrode and the conductive particles to the connection target member can be increased. The connection resistance between the electrodes can be further reduced.

  Although it is preferable that the core particles and the inorganic shell are not chemically bonded, they may be chemically bonded. As a method of chemically bonding between the core particle and the inorganic shell, a functional group capable of reacting with a functional group of a material constituting the inorganic shell is introduced on the surface of the core particle, and then on the surface of the core particle. Examples thereof include a method of forming an inorganic shell with the material constituting the inorganic shell. Specific examples include a method in which the surface of the core particle is surface-treated with a coupling agent, and then a silane alkoxide is formed into a shell-like material by a sol-gel method on the surface of the core particle.

(Conductive particles)
The conductive particles include the above-described protruding particles and a conductive layer disposed on the surface of the protruding particles. The conductive layer preferably has a plurality of protrusions on the outer surface. The protrusions of the conductive layer can be easily formed due to the protrusions of the inorganic shell.

  In FIG. 1, the electroconductive particle which concerns on the 1st Embodiment of this invention is shown with sectional drawing.

  A conductive particle 1 shown in FIG. 1 has a protruding particle 11 and a conductive layer 2 disposed on the surface of the protruding particle 11. The conductive layer 2 covers the surface of the protruding particle 11. The conductive particle 1 is a coated particle in which the surface of the protruding particle 11 is coated with the conductive layer 2. The conductive layer 2 has a protrusion 2a on the outer surface. The conductive particles 1 have protrusions on the conductive surface.

  The protruding particle 11 includes a core particle 12 and an inorganic shell 13 disposed on the surface of the core particle 12. The inorganic shell 13 covers the surface of the core particle 12. The conductive layer 2 is disposed on the surface of the inorganic shell 13. The conductive layer 2 covers the surface of the inorganic shell 13. The inorganic shell 13 has a protrusion 13a on the outer surface.

  The inorganic shell 13 is thicker than the first inorganic shell portion 13A and the first inorganic shell portion 13A, and the second inorganic shell portion 13B is formed with a plurality of protrusions 13a on the outer surface of the inorganic shell 13. And have. The first inorganic shell portion 13A and the second inorganic shell portion 13B are continuous. A portion excluding the plurality of protrusions 13a is the first inorganic shell portion 13A. The plurality of protrusions 13a are located in the second inorganic shell portion 13B where the inorganic shell 13 is thick.

  The protrusion 2a is derived from the protrusion 13a. That is, the protrusion 2a is formed by the outer surface of the inorganic shell 13 being raised by the protrusion 13a.

  In the conductive particle 1, other members (particles or the like) for forming a protrusion are used between the core particle 12 and the inorganic shell 13 in order to form the protrusion 13 a on the outer surface of the inorganic shell 13. Absent.

  In FIG. 2, the electroconductive particle which concerns on the 2nd Embodiment of this invention is shown with sectional drawing.

  The conductive particles 21 shown in FIG. 2 have the protruding particles 11, the conductive layer 22 disposed on the surface of the protruding particles 11, and the plurality of insulating substances 3 disposed on the outer surface of the conductive layer 22. . The conductive layer 22 has a protrusion 22a on the outer surface. The conductive particles 21 have protrusions on the conductive surface.

  The conductive layer 22 includes a first conductive layer 22A that is an inner layer and a second conductive layer 22B that is an outer layer. On the surface of the protruding particle 11, the first conductive layer 22 </ b> A is disposed. On the surface of the inorganic shell 13, the first conductive layer 22A is disposed. A second conductive layer 22B is disposed on the surface of the first conductive layer 22A. The first conductive layer 22A is disposed between the inorganic shell 13 and the second conductive layer 22B. The first conductive layer 22A has a protrusion 22Aa on the outer surface. The second conductive layer 22B has a protrusion 22Ba on the outer surface.

  The protrusions 22a, 22Aa, and 22Ba are formed from the protrusion 13a. That is, the outer surface of the inorganic shell 13 is raised by the protrusion 13a, whereby the protrusions 22a, 22Aa, and 22Ba are formed.

  The conductive particles 21 have the insulating material 3 disposed on the outer surface of the conductive layer 22. At least a part of the outer surface of the conductive layer 22 is covered with the insulating material 3. The insulating substance 3 is made of an insulating material and is an insulating particle. Thus, the said electroconductive particle may have the insulating substance arrange | positioned on the outer surface of a conductive layer.

  Further, like the conductive particles 1 and 21, the conductive particles preferably have protrusions on the conductive surface. The conductive particles preferably have protrusions on the outer surface of the conductive layer.

  The metal for forming the conductive layer 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, and these. And the like. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable.

  Like the electroconductive particle 1, the said conductive layer may be formed of one layer. Like the conductive particles 21, the conductive layer may be formed of a plurality of layers. That is, the conductive layer may have a stacked structure of two or more layers. When the conductive layer 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 is a gold layer. Is more preferable. When the outermost layer is these preferred conductive layers, the connection resistance between the electrodes is further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance is further enhanced.

  The method for forming the conductive layer in the protruding particles is not particularly limited. Examples of the method for forming the conductive layer include a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of the protruding particles with a metal powder or a paste containing a metal powder and a binder. Is mentioned. Especially, since formation of a conductive layer is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

  The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 520 μm or less, more preferably 500 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, and particularly preferably 20 μm. It is as follows. When the particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrode becomes sufficiently large when the electrodes are connected using the conductive particles, and the conductive layer When forming the conductive particles, it becomes difficult to form aggregated conductive particles. Further, the interval between the electrodes connected via the conductive particles does not become too large, and the conductive layer is difficult to peel from the surface of the protruding particles. Further, when the particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conductive particles can be suitably used for the use of the conductive material.

  The particle diameter of the conductive particles means the diameter when the conductive particles are true spherical, and means the maximum diameter when the conductive particles have a shape other than the true spherical shape.

  The thickness of the conductive layer (when the conductive layer is a multilayer, the total thickness of the conductive layer) 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, Preferably it is 0.5 micrometer or less, Most preferably, it is 0.3 micrometer or less. When the thickness of the conductive layer is not less than the above lower limit and not more than the above upper limit, sufficient conductivity is obtained, and the conductive particles do not become too hard, and the conductive particles are sufficiently deformed when connecting the electrodes. .

  When the conductive layer is formed of a plurality of layers, the thickness of the outermost conductive layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, more preferably 0. .1 μm or less. When the thickness of the outermost conductive layer is not less than the above lower limit and not more than the above upper limit, the coating with the outermost conductive layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is further increased. Lower. Further, the thinner the gold layer when the outermost layer is a gold layer, the lower the cost.

  The thickness of the conductive layer can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (TEM).

  The conductive particles may include an insulating substance disposed on the outer surface of the conductive layer. In this case, when the conductive particles are used for connection between the electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles are in contact with each other, an insulating material is present between the plurality of electrodes, so that it is possible to prevent a short circuit between electrodes adjacent in the lateral direction instead of between the upper and lower electrodes. In addition, the insulating substance between the conductive layer of an electroconductive particle and an electrode can be easily excluded by pressurizing electroconductive particle with two electrodes in the case of the connection between electrodes. When the conductive particles have protrusions on the surface of the conductive layer, the insulating substance between the conductive layer of the conductive particles and the electrode can be more easily eliminated. The insulating substance is preferably an insulating resin layer or insulating particles, and more preferably insulating particles. The insulating particles are preferably insulating resin particles.

(Conductive material)
The conductive material includes the conductive particles described above and a binder resin. The conductive particles are preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material.

  The binder resin is not particularly limited. As the binder resin, a known insulating resin is used. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

  Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include an epoxy resin, a urethane resin, a polyimide resin, and an unsaturated polyester resin. 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 a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogenated product of a styrene block copolymer. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

  In addition to the conductive particles and the binder resin, the conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. Various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant may be contained.

  The method for dispersing the conductive particles in the binder resin is not particularly limited, and a conventionally known dispersion method can be used. Examples of a method for dispersing the conductive particles in the binder resin include a method in which the conductive particles are added to the binder resin and then kneaded and dispersed with a planetary mixer or the like. The conductive particles are dispersed in water. Alternatively, after uniformly dispersing in an organic solvent using a homogenizer or the like, it is added to the binder resin, kneaded and dispersed with a planetary mixer or the like, and the binder resin is diluted with water or an organic solvent. Then, the method of adding the said electroconductive particle, kneading with a planetary mixer etc. and disperse | distributing is mentioned.

  The conductive material can be used as a conductive paste and a conductive film. When the conductive material according to the present invention is a conductive film, a film that does not include conductive particles may be laminated on a conductive film that includes conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  In 100% by weight of the conductive material, the content of the binder resin 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.% or more. It is 99 weight% or less, More preferably, it is 99.9 weight% or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further increased.

  In 100% by weight of the conductive material, the content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 40% by weight or less, more preferably 20% by weight or less, More preferably, it is 10 weight% or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further enhanced.

(Connection structure and liquid crystal display element)
A connection structure can be obtained by connecting the connection target members using the conductive particles described above or using a conductive material including the conductive particles described above and a binder resin.

  The connection structure includes a first connection target member, a second connection target member, and a connection portion connecting the first connection target member and the second connection target member, and the connection portion. Is preferably formed of the above-described conductive particles, or a connection structure formed of a conductive material containing the above-described conductive particles and a binder resin. When the conductive particles are used alone, the connection part itself is the conductive particles. That is, the first and second connection target members are connected by the conductive particles. The conductive material used for obtaining the connection structure is preferably an anisotropic conductive material.

  The first connection target member preferably has a first electrode on the surface. The second connection target member preferably has a second electrode on the surface. It is preferable that the first electrode and the second electrode are electrically connected by the conductive particles.

  FIG. 3 is a front sectional view schematically showing a connection structure using the conductive particles 1 shown in FIG.

  The connection structure 51 shown in FIG. 3 is a connection that connects the first connection target member 52, the second connection target member 53, and the first connection target member 52 and the second connection target member 53. Part 54. The connection part 54 is formed of a conductive material containing the conductive particles 1 and a binder resin. In FIG. 3, the conductive particles 1 are schematically shown for convenience of illustration. Instead of the conductive particles 1, other conductive particles such as the conductive particles 21 may be used.

  The first connection target member 52 has a plurality of first electrodes 52a on the surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the surface (lower surface). The first electrode 52 a and the second electrode 53 a are electrically connected by one or a plurality of conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.

The manufacturing method of the connection structure is not particularly limited. As an example of a method of manufacturing a connection structure, a method of placing the conductive material between a first connection target member and a second connection target member to obtain a laminate, and then heating and pressurizing the laminate Etc. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > -4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120-220 degreeC. The pressure of the pressurization for connecting the electrode of the flexible printed board, the electrode arranged on the resin film, and the electrode of the touch panel is about 9.8 × 10 ^{4 to} 1.0 × 10 ⁶ Pa.

  Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. 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 on the connection target member in a paste-like state.

  The conductive particles and the conductive material are also suitably used for touch panels. Therefore, the connection target member is preferably a flexible printed circuit board or a connection target member in which an electrode is disposed on the surface of a resin film. The connection target member is preferably a flexible printed board, and is preferably a connection target member in which an electrode is disposed on the surface of the resin film. The flexible printed board generally has electrodes on the surface.

  Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a molybdenum electrode, and a tungsten electrode. When the connection object member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.

  The protruding particles are preferably used as a liquid crystal display element spacer. That is, the protruding particles include a liquid crystal display element including a pair of substrates constituting a liquid crystal cell, a liquid crystal sealed between the pair of substrates, and a spacer for a liquid crystal display element disposed between the pair of substrates. It is preferably used for obtaining.

  FIG. 4 is a cross-sectional view of a liquid crystal display element using the protruding particles according to one embodiment of the present invention as a liquid crystal display element spacer.

A liquid crystal display element 81 shown in FIG. 4 has a pair of transparent glass substrates 82. The transparent glass substrate 82 has an insulating film (not shown) on the opposing surface. Examples of the material for the insulating film include SiO ₂ . A transparent electrode 83 is formed on the insulating film in the transparent glass substrate 82. Examples of the material of the transparent electrode 83 include ITO. The transparent electrode 83 can be formed by patterning, for example, by photolithography. An alignment film 84 is formed on the transparent electrode 83 on the surface of the transparent glass substrate 82. Examples of the material of the alignment film 84 include polyimide.

  A liquid crystal 85 is sealed between the pair of transparent glass substrates 82. A plurality of protruding particles 11 are arranged between the pair of transparent glass substrates 82. The protruding particles 11 are used as spacers for liquid crystal display elements. The spacing between the pair of transparent glass substrates 82 is regulated by the plurality of protruding particles 11. A sealing agent 86 is disposed between the edges of the pair of transparent glass substrates 82. Outflow of the liquid crystal 85 to the outside is prevented by the sealing agent 86.

In the liquid crystal display element, the arrangement density of spacers for liquid crystal display elements per 1 mm ² is preferably 10 pieces / mm ² or more, and preferably 1000 pieces / mm ² or less. When the arrangement density is 10 pieces / mm ² or more, the cell gap becomes even more uniform. When the arrangement density is 1000 / mm ² or less, the contrast of the liquid crystal display element is further improved.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Production of Protrusion Particles As core particles, Sekisui Chemical Co., Ltd. “Micropearl ELP-00375” (styrene / acrylic copolymer, average particle size of 3.75 μm), which is an organic core particle, was prepared. 100 parts by weight of the organic core particles and 40 parts by weight of hexadecyltrimethylammonium bromide as a surfactant were dispersed in a mixed solvent of 1800 parts by weight of acetone and 200 parts by weight of water, and placed in a separable flask. . 160 parts by weight of 25% by weight aqueous ammonia solution was added and stirred while applying ultrasonic waves. A solution prepared by dissolving 600 parts by weight of tetraethoxysilane in 1200 parts by weight of acetone was added, and the mixture was stirred at 25 ° C. for 24 hours while applying ultrasonic waves. The reaction solution is taken out, suction filtered through a PTFE (polytetrafluoroethylene) membrane filter, washed with acetone twice, and then dried in a vacuum dryer at 50 ° C. for 24 hours. Obtained.

  The obtained pre-fired protruding particles were baked at 200 ° C. for 6 hours to obtain protruding particles.

(2) Production of conductive particles After the obtained protruding particles were washed and dried, a nickel layer was formed on the surface of the obtained protruding particles by an electroless plating method to produce conductive particles. The nickel layer had a thickness of 0.1 μm.

(Example 2)
As the organic core particles, “Micropearl ELP-00375” (styrene / acrylic copolymer, average particle diameter of 3.75 μm) manufactured by Sekisui Chemical Co., Ltd. was prepared. 100 parts by weight of the organic core particles and 40 parts by weight of hexadecyltrimethylammonium bromide as a surfactant were dispersed in a mixed solvent of 1800 parts by weight of acetonitrile and 200 parts by weight of water, and placed in a separable flask. . 160 parts by weight of 25% by weight aqueous ammonia solution was added and stirred while applying ultrasonic waves. A solution prepared by dissolving 600 parts by weight of tetraethoxysilane in 1200 parts by weight of acetonitrile was added, and the mixture was stirred at 25 ° C. for 24 hours while applying ultrasonic waves. The reaction solution is taken out, suction filtered through a membrane filter made of PTFE (polytetrafluoroethylene), washed twice with acetonitrile, then dried in a vacuum dryer at 50 ° C. for 24 hours, Obtained.

  The obtained pre-fired protruding particles were baked at 200 ° C. for 6 hours to obtain protruding particles. Using the obtained projecting particles, conductive particles were obtained in the same manner as in Example 1.

(Example 3)
As the organic core particles, “Micropearl ELP-00375” (styrene / acrylic copolymer, average particle diameter of 3.75 μm) manufactured by Sekisui Chemical Co., Ltd. was prepared. 100 parts by weight of the organic core particles and 40 parts by weight of hexadecyltrimethylammonium bromide as a surfactant were dispersed in a mixed solvent of 1800 parts by weight of acetone and 200 parts by weight of water, and placed in a separable flask. . 320 parts by weight of 25% by weight aqueous ammonia solution was added and stirred while applying ultrasonic waves. A solution prepared by dissolving 600 parts by weight of tetraethoxysilane in 1200 parts by weight of acetone was added, and the mixture was stirred at 25 ° C. for 24 hours while applying ultrasonic waves. The reaction solution is taken out, suction filtered through a PTFE (polytetrafluoroethylene) membrane filter, washed with acetone twice, and then dried in a vacuum dryer at 50 ° C. for 24 hours. Obtained.

  The obtained pre-fired protruding particles were baked at 200 ° C. for 6 hours to obtain protruding particles. Using the obtained projecting particles, conductive particles were obtained in the same manner as in Example 1.

Example 4
As the organic core particles, “Micropearl ELP-00375” (styrene / acrylic copolymer, average particle diameter of 3.75 μm) manufactured by Sekisui Chemical Co., Ltd. was prepared. 100 parts by weight of the organic core particles and 40 parts by weight of hexadecyltrimethylammonium bromide as a surfactant were dispersed in a mixed solvent of 1800 parts by weight of acetonitrile and 200 parts by weight of water, and placed in a separable flask. . 320 parts by weight of 25% by weight aqueous ammonia solution was added and stirred while applying ultrasonic waves. A solution prepared by dissolving 600 parts by weight of tetraethoxysilane in 1200 parts by weight of acetonitrile was added, and the mixture was stirred at 25 ° C. for 24 hours while applying ultrasonic waves. The reaction solution is taken out, suction filtered through a membrane filter made of PTFE (polytetrafluoroethylene), washed twice with acetonitrile, then dried in a vacuum dryer at 50 ° C. for 24 hours, Obtained.

  The obtained pre-fired protruding particles were baked at 200 ° C. for 6 hours to obtain protruding particles. Using the obtained projecting particles, conductive particles were obtained in the same manner as in Example 1.

(Example 5)
As the core particles, “Micropearl SI-0038” (silica particles, average particle size 3.80 μm) manufactured by Sekisui Chemical Co., Ltd., which is an inorganic core particle, was prepared. Protruding particles and conductive particles were obtained in the same manner as in Example 1 except that the organic core particles were changed to inorganic core particles.

(Example 6)
As the organic core particles, “Micropearl ELP-00375” (styrene / acrylic copolymer, average particle diameter of 3.75 μm) manufactured by Sekisui Chemical Co., Ltd. was prepared. 100 parts by weight of the organic core particles and 40 parts by weight of hexadecyltrimethylammonium bromide as a surfactant were dispersed in a mixed solvent of 1800 parts by weight of acetonitrile and 200 parts by weight of water, and placed in a separable flask. . 120 parts by weight of 25% by weight aqueous ammonia solution was added and stirred while applying ultrasonic waves. A solution prepared by dissolving 600 parts by weight of tetraethoxysilane in 1200 parts by weight of acetonitrile was added, and the mixture was stirred at 25 ° C. for 24 hours while applying ultrasonic waves. The reaction solution is taken out, suction filtered through a membrane filter made of PTFE (polytetrafluoroethylene), washed twice with acetonitrile, then dried in a vacuum dryer at 50 ° C. for 24 hours, Obtained.

  The obtained pre-fired protruding particles were baked at 200 ° C. for 6 hours to obtain protruding particles. Using the obtained projecting particles, conductive particles were obtained in the same manner as in Example 1.

(Comparative Example 1)
Protruding particles and conductive particles were obtained in the same manner as in Example 1 except that tetraethoxysilane was changed to methyltrimethoxysilane.

(Comparative Example 2)
“Micropearl ELP-00375” (styrene / acrylic copolymer, average particle size 3.75 μm) manufactured by Sekisui Chemical Co., Ltd., which is an organic core particle, is prepared by “Micropearl SI-0038, manufactured by Sekisui Chemical Co., Ltd., which is an inorganic core particle. (Silica particles, average particle size 3.80 μm) and projecting particles and conductive particles were obtained in the same manner as in Example 1 except that tetraethoxysilane was changed to methyltrimethoxysilane.

(Comparative Example 3)
Protruding particles and conductive particles were obtained in the same manner as in Example 1 except that firing was not performed at 200 ° C. for 6 hours.

(Evaluation)
(1) Projection height of projection particle, number of projections of projection particle, composition analysis and structure analysis of projection particle, particle size of projection particle, particle size of core particle and shell thickness The obtained projection particle is scanned. Take a 3000 times particle image with a scanning electron microscope ("S-3500N" manufactured by Hitachi High-Technology Corporation), measure the particle size of 50 particles in the obtained image with calipers, find the number average, and project The particle size of the particles was determined. Further, the height of the protrusion and the number of protrusions were evaluated using the obtained image.

  Moreover, the obtained protrusion particle | grains produced the section | slice by FIB, and measured the EDS elemental image with the atomic resolution analysis electron microscope (JEM-ARM200F).

  The particle diameter of the core particles used for producing the protruding particles was also measured by the same method as described above. The thickness of the shell was determined from the difference between the particle size of the protruding particles and the particle size of the core particles.

(2) The ratio of the number of silicon atoms in which the four —O—Si groups are directly bonded and the four oxygen atoms in the four —O—Si groups are directly bonded (the ratio of the number of Q4 (% ))
In the inorganic shell in the obtained protruding particles, using a NMR spectrum analyzer (“ECX400” manufactured by JEOL), solid ²⁹ Si NMR spectrum analysis (measurement frequency: 79.4254 MHz, pulse width: 3.7, sample holder: 4 mm) , Sample rotation speed: 10 kHz, integration number: 3600, measurement temperature, 25 ° C., waiting time: 5 times the time when the maximum peak was detected) Q4 (silicon atom in which four oxygen atoms are directly bonded) ) And the peak area of Q1 to Q3 (silicon atoms in which 1 to 3 oxygen atoms are directly bonded), the total number of silicon atoms contained in the inorganic shell is 100%. Silicon in which four —O—Si groups are directly bonded and four oxygen atoms in the four —O—Si groups are directly bonded To determine the ratio of the number of children (ratio of the number of Q4).

(3) The compression elastic modulus of the protruding particles (10% K value and 30% K value)
The above-mentioned compression elastic modulus (10% K value and 30% K value) of the obtained projection particles was measured by the above-described method using a micro compression tester (“Fischer Scope H-100” manufactured by Fischer).

(4) Ease of detachment of protrusions 1.0 g of the obtained protrusion particles were put into a mortar part of an automatic mortar (“AMM-140D” manufactured by Nikko Corporation) and stirred at a pestle part of 10 rpm and a mortar part of 6 rpm for 1 minute. After stirring, the rate at which the protrusions were removed was evaluated with a scanning electron microscope. The ease of detachment of the protrusion was determined according to the following criteria.

[Criteria for ease of protrusion removal]
◯: Less than 5 percentage of protruding particles with at least one projection per 100 protruding grains ○: 5 percentage of protruding particles with at least one projection removed per 100 protruding particles Or more, less than 10 △: the ratio of protruding particles from which at least one protrusion is detached per 100 protruding particles is 10 or more and less than 20 ×: at least one protrusion is removed per 100 protruding particles The ratio of protruding particles is 20 or more

(5) Connection resistance Fabrication of connection structure:
10 parts by weight of bisphenol A type epoxy resin (“Epicoat 1009” manufactured by Mitsubishi Chemical Corporation), 40 parts by weight of acrylic rubber (weight average molecular weight of about 800,000), 200 parts by weight of methyl ethyl ketone, and a microcapsule type curing agent (Asahi Kasei Chemicals) "HX3941HP" manufactured by 50 parts by weight and 2 parts by weight of silane coupling agent ("SH6040" manufactured by Toray Dow Corning Silicone Co., Ltd.) were mixed, and the resulting conductive particles (using organic-inorganic hybrid particles before heating) Was added and dispersed so that the content was 3% by weight to obtain a resin composition.

  The obtained resin composition was applied to a 50 μm-thick PET (polyethylene terephthalate) film whose one surface was released from the mold, and dried with hot air at 70 ° C. for 5 minutes to produce an anisotropic conductive film. The thickness of the obtained anisotropic conductive film was 12 μm.

  The obtained anisotropic conductive film was cut into a size of 5 mm × 5 mm. PET substrate (width 3 cm, length 3 cm) provided with ITO (height 0.1 μm, L / S = 20 μm / 20 μm) having a lead wire for resistance measurement on one side of the cut anisotropic conductive film Affixed to the center of the ITO electrode. Subsequently, the two-layer flexible printed circuit board (width 2cm, length 1cm) provided with the same gold electrode was bonded after aligning so that electrodes might overlap. The laminate of the PET substrate and the two-layer flexible printed circuit board was thermocompression bonded under pressure bonding conditions of 10 N, 180 ° C., and 20 seconds to obtain a connection structure X using organic / inorganic hybrid particles before heating. In addition, the two-layer flexible printed board by which the copper electrode was formed in the polyimide film and the copper electrode surface was Au-plated was used.

  The connection resistance between the opposing electrodes of the obtained connection structure X was measured by a four-terminal method. Connection resistance was determined according to the following criteria.

[Evaluation criteria for connection resistance]
◯: Connection resistance is 3.0Ω or less ○: Connection resistance exceeds 3.0Ω, 4.0Ω or less △: Connection resistance exceeds 4.0Ω, 5.0Ω or less ×: Connection resistance exceeds 5.0Ω

(6) Light scattering property 10 parts by weight of the obtained protruding particles and 10000 parts by weight of a commercially available polyethylene resin pellet are mixed, and in an extruder, a molding temperature of 100 ° C., a screw rotation speed of 15 to 30 rpm, and a barrel residence time. The mixture was kneaded for 5 to 20 minutes to obtain a resin film containing protruding particles.

  Then, a paper printed with numbers 1 to 9 having a size of 8 points in an MS Gothic typeface was placed on a desk under a fluorescent lamp. Observed from a distance of 30 cm through the PE film obtained above, the distance between the film and the paper where the numbers could not be determined was measured, and the light scattering property was determined according to the following criteria.

[Criteria for light scattering properties]
○: The distance at which the numbers cannot be seen is less than 5 cm, and the light scattering property is good. Δ: The distance at which the numbers cannot be seen is 5 cm or more and less than 10 cm, and the light scattering property is slightly good. Exceeding light scattering

  The results are shown in Table 1 below.

(7) Example of use as spacer for liquid crystal display element Production of STN type liquid crystal display element:
In a dispersion medium containing 70 parts by weight of isopropyl alcohol and 30 parts by weight of water, the spacers (projection particles) for liquid crystal display elements of Examples 1 to 6 and Comparative Examples 1 to 3 were solidified in 100% by weight of the obtained spacer dispersion. It added so that a partial concentration might be 2 weight%, it stirred, and the spacer dispersion liquid for liquid crystal display elements was obtained.

An SiO ₂ film was deposited on one surface of a pair of transparent glass plates (length 50 mm, width 50 mm, thickness 0.4 mm) by a CVD method, and then an ITO film was formed on the entire surface of the SiO ₂ film by sputtering. A polyimide alignment film composition (“SE3510” manufactured by Nissan Chemical Industries, Ltd.) was applied to the obtained glass substrate with an ITO film by a spin coating method and baked at 280 ° C. for 90 minutes to form a polyimide alignment film. After the rubbing treatment was performed on the alignment film, liquid crystal display element spacers were wet-sprayed on the alignment film side of one substrate so that the number of spacers for a liquid crystal display element was 100 to 200 per 1 mm ² . After forming a sealant around the other substrate, this substrate and the substrate on which the spacers were spread were placed opposite to each other so that the rubbing direction was 90 °, and both were bonded together. Then, it processed at 160 degreeC for 90 minute (s), the sealing agent was hardened, and the empty cell (screen which does not contain liquid crystal) was obtained. An STN type liquid crystal containing a chiral agent (made by DIC) was injected into the obtained empty cell, and then the injection port was closed with a sealant, followed by heat treatment at 120 ° C. for 30 minutes to produce an STN type liquid crystal display element. Obtained.

  In the obtained liquid crystal display element, the space | interval between board | substrates was favorably controlled by the spacer for liquid crystal display elements of Examples 1-6. Moreover, the liquid crystal display element using the spacer for liquid crystal display elements of Examples 1-6 showed favorable display quality. In addition, when the liquid crystal display element spacers of Examples 1 to 4 and 6 were used, the display quality was much better than when the liquid crystal display element spacer of Example 5 was used.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle 2 ... Conductive layer 2a ... Protrusion 3 ... Insulating substance 11 ... Protrusion particle 12 ... Core particle 13 ... Inorganic shell 13a ... Protrusion 13A ... 1st inorganic shell part 13B ... 2nd inorganic shell part 21 ... Conductive particles 22 ... conductive layer 22a ... projection 22A ... first conductive layer 22Aa ... projection 22B ... second conductive layer 22Ba ... projection 51 ... connection structure 52 ... first connection target member 52a ... first electrode 53 ... 2nd connection object member 53a ... 2nd electrode 54 ... Connection part 81 ... Liquid crystal display element 82 ... Transparent glass substrate 83 ... Transparent electrode 84 ... Alignment film 85 ... Liquid crystal 86 ... Sealing agent

Claims (9)

Comprising core particles and an inorganic shell disposed on the surface of the core particles;
The inorganic shell has a plurality of protrusions on the outer surface;
The inorganic shell is formed of a silane alkoxide, and 4 —O—Si groups are directly bonded and the four —O— in 100% of the total number of silicon atoms contained in the inorganic shell. ratio of the number of silicon atoms four oxygen atoms in the Si group is directly bonded is Ri der least 50%,
The inorganic shell has a first inorganic shell portion and a second inorganic shell portion that is thicker than the first inorganic shell portion and has a plurality of protrusions formed on the outer surface of the inorganic shell. you, the projection particles.   The protruding particle according to claim 1, wherein the inorganic shell is formed to have a plurality of protrusions on an outer surface by a sol-gel method using silane alkoxide.   The protruding particle according to claim 1, wherein the height of the protrusion is 50 nm or more and 500 nm or less.   The protruding particle according to claim 1, wherein the core particle is an organic core particle. Before SL first inorganic shell portion and said second inorganic shell portions are continuous, projections particles according to any one of claims 1 to 4.   6. The protruding particle according to claim 1, wherein a conductive layer is formed on a surface and used to obtain conductive particles having the conductive layer, or used as a spacer for a liquid crystal display element. . The protruding particles according to any one of claims 1 to 6,
A conductive particle comprising: a conductive layer disposed on a surface of the protruding particle and having a plurality of protrusions on an outer surface. Containing conductive particles and a binder resin,
The conductive particles include the protruding particles according to any one of claims 1 to 6 and a conductive layer disposed on a surface of the protruding particles and having a plurality of protrusions on an outer surface. Conductive material. A first connection object member having a first electrode on its surface;
A second connection target member having a second electrode on its surface;
A connection portion connecting the first connection target member and the second connection target member;
The connecting portion is formed of conductive particles or formed of a conductive material containing the conductive particles and a binder resin;
The conductive particle comprises the protruding particle according to any one of claims 1 to 6, and a conductive layer disposed on a surface of the protruding particle and having a plurality of protrusions on an outer surface,
A connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.

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