TW202313733A - Polymer particle and method of producing the same - Google Patents

Abstract

An object of the present invention is to provide a polymer particle having both monodispersity and high hardness, and a method of producing the same. The polymer particle of the present invention is characterized by including a (meth)acrylic acid -based resin that has a structure obtained by polymerizing a (meth)acrylic acid ester (A) having a cyclic ether structure, and cyclic ether sites in the cyclic ether structure are ring-opening-polymerized with each other.

Description

Polymer particle and its production method

The present invention relates to a polymer particle and its manufacturing method.

In the connection of semiconductor elements, wiring boards, etc., in order to electronically connect a large number of opposing electrodes or wirings, a connection method using an anisotropic conductive material is widely used. The anisotropic conductive material is a material in which conductive particles are dispersed in a binder resin (adhesive), such as anisotropic conductive paste (Anisotropic Conductive Paste; ACP), anisotropic conductive film (Anisotropic Conductive Film; ACF) )wait.

Conductive particles for heterotropic conductive connections are formed by covering polymer particles as a core with a metal layer. In recent years, in order to improve the performance of the anisotropic conductive material, the development of conductive particles contained in the anisotropic conductive material is progressing. Since the compression deformation characteristics of the conductive particles are strongly influenced by the characteristics of the polymer particles serving as the core, in order to improve the connection reliability at the time of pressure connection, it is required to increase the hardness of the polymer particles. Furthermore, polymer particles used for anisotropic conductive materials require monodispersity from the viewpoint of connection reliability.

Patent Document 1 discloses a cross-linked polymer particle obtained through the following steps (a) and (b): radically polymerizing a polymerizable monomer having a double bond and a functional group reacted with an amine group and The step (a) of obtaining the mother particle, and after the step (a), the step of contacting the mother particle with an amino compound having an amine group, and further crosslinking the crosslinked polymer by reacting the functional group with the amine group (b). The crosslinked polymer particles described in Patent Document 1 are characterized by having good compression properties.

In addition, Patent Document 2 discloses a method for producing crosslinked microparticles and crosslinked particles produced by the production method. The production method includes: allowing organic microparticles having a glycidyl group to absorb amines having two or more A step of compounding the group, and a crosslinking step of reacting the aforementioned glycidyl group with the aforementioned amine group. The crosslinked microparticles described in Patent Document 2 are characterized by being monodisperse and having excellent solvent resistance and heat resistance.

[Prior Art Literature]

[Patent Document]

Patent Document 1: International Publication No. 2011/158761

Patent Document 2: Japanese Patent Laid-Open No. 2001-206954

The polymer particles proposed in the above-mentioned Patent Documents 1 and 2 are insufficient to achieve both monodispersity and high hardness. An object of the present invention is to provide polymer particles having both monodispersity and increased hardness and a method for producing the same.

The inventors of the present invention have made efforts to examine and solve the above-mentioned problems. As a result, it has been found that by adding an imidazole compound or/and an amino compound having a tertiary amino group to a (meth)acrylic resin containing a cyclic ether structure, the ring-opening polymerization of the cyclic ether can be achieved. The above-mentioned problems have been solved, and the present invention has been accomplished.

The present invention relates to, for example, the following [1] to [8].

[1] A polymer particle comprising a (meth)acrylic resin having a (meth)acrylate (A) having a cyclic ether structure polymerized and the ring A structure formed by ring-opening polymerization of cyclic ether parts in the ether-like structure.

[2] The polymer particles according to the above [1], wherein the (meth)acrylic resin further contains polymerizable monomers derived from the (meth)acrylate (A) having a cyclic ether structure. The structure of body (B).

[3] The polymer particle according to [2] above, wherein the polymerizable monomer (B) is selected from the group consisting of monomers having 1 to 4 (meth)acryl groups in one molecule. At least 1 compound in the group.

[4] The polymer particles according to any one of [1] to [3] above, wherein the (meth)acrylate (A) having a cyclic ether structure is represented by the following formula (1): compound.

[In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group with 1 to 10 carbons, x represents an integer from 1 to 6, Y represents a single bond or -O-CH ₂ - , z represents an integer from 0 to 2. ]

[5] The polymer particle according to any one of [1] to [4] above, which comprises a (meth)acrylic resin having a cyclic ether structure. (Meth)acrylate (A) is polymerized and A structure in which an imidazole compound is added to a part of the ring-opened part of the aforementioned cyclic ether structure.

[6] The polymer particle according to any one of [1] to [5] above, wherein the 10% K value in the polymer particle is 3,000 to 7,000 N/mm ² .

[7] A method for producing the polymer particle described in any one of the aforementioned [1] to [6], comprising:

In step (1), the polymerizable monomer component comprising (meth)acrylic acid ester (A) having a cyclic ether structure is subjected to radical polymerization to obtain mother particles comprising (meth)acrylic resin;

Step (2) is to make the above-mentioned mother particles contact with the imidazole compound or/and the amino compound with a tertiary amino group, and make the ring-opening polymerization of the cyclic ether parts in the above-mentioned cyclic ether structure to obtain a compound containing (methyl ) polymer particles of acrylic resin, wherein the (meth)acrylic resin has a structure formed by ring-opening polymerization of cyclic ether moieties; and

Step (3) is to powder the aforementioned polymer particles.

[8] The polymer particle according to any one of [1] to [6] above, which is used as a conductive particle of an anisotropic conductive adhesive.

According to the present invention, it is possible to provide polymer particles having both monodispersity and increased hardness, and a method for producing the same.

Hereinafter, the polymer particle of this invention and its manufacturing method are demonstrated concretely.

[polymer particles]

The polymer particles of the present invention contain a (meth)acrylic resin. The (meth)acrylic resin has a structure obtained by polymerizing a (meth)acrylate (A) having a cyclic ether structure and ring-opening polymerization of cyclic ether sites in the cyclic ether structure.

In addition, in this specification, the general term of (meth)acrylic acid and methacrylic acid may be acrylic acid or methacrylic acid. (Meth) acrylate is a general term for acrylate and methacrylate, and may be either acrylate or methacrylate. (Meth)acryl is a general term for acryl and methacryl, which can be either acryl or methacryl.

In the present invention, "(meth)acrylic resin" refers to a constitutional unit derived from (meth)acrylic acid and a constitution derived from acrylate, relative to 100% by mass of the total constitutional units of (meth)acrylic resin. The total of the unit, the structural unit derived from acrylate, the structural unit derived from methacrylic acid, the structural unit derived from methacrylate, and the structural unit derived from methacrylate is 50% by mass or more of the resin.

Since the polymer particles of the present invention contain the above-mentioned (meth)acrylic resin, they can achieve both monodispersity and high hardness.

[Manufacturing method of polymer particles]

The manufacture method of polymer particle of the present invention comprises:

Step (1): Carrying out free-radical polymerization of the monomer component comprising (meth)acrylic acid ester (A) having a cyclic ether structure, to obtain mother particles comprising (meth)acrylic resin;

Step (2): contacting the above-mentioned mother particle with an imidazole compound or/and an amino compound having a tertiary amino group, so that the cyclic ether parts in the above-mentioned cyclic ether structure are ring-opened and polymerized with each other to obtain a compound containing a cyclic Polymer particles of (meth)acrylic resin having a structure formed by ring-opening polymerization of ether moieties; and

Step (3): powdering the aforementioned polymer particles.

In the method for producing polymer particles of the present invention, the synthesis can be completed by a one-pot synthesis method from the particle production steps before crosslinking to the polymer particles obtained through the crosslinking reaction, so that the production work can be simplified.

<step 1)>

The mother particle system containing (meth)acrylic resin can be obtained by radically polymerizing the polymerizable monomer component containing (meth)acrylate (A) which has a cyclic ether structure by a well-known method.

"(Meth)acrylates with Cyclic Ether Structure (A)"

(Meth)acrylate (A) having a cyclic ether structure (hereinafter also referred to as "(meth)acrylate (A)") is not particularly special if it is a (meth)acrylate having a cyclic ether structure in the molecule. As a limitation, known (meth)acrylates having a cyclic ether structure can be widely used.

烷)、1,2-環氧環己烷、1,2-環氧環戊烷、1,4-環氧環己烷、1-甲基-1,2-環氧環己烷、外-2,3-環氧降莰烷等。其中，從反應性高且藉由觸媒易使環狀醚部位彼此開環聚合的觀點而言，較佳為環氧乙烷。 As far as the cyclic ether structure is concerned, for example, oxirane (ethylene oxide), oxetane (oxygen), pentoxide (tetrahydrofuran), oxirane (tetrahydropyran), 1 ,4-Dioxane (1,4-di

alkane), 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 1,4-epoxycyclohexane, 1-methyl-1,2-epoxycyclohexane, exo- 2,3-epoxynorbornane, etc. Among these, ethylene oxide is preferred from the viewpoint of high reactivity and ease of ring-opening polymerization of cyclic ether moieties with a catalyst.

(Meth)acrylate (A) has a structure in which a cyclic ether structure is directly or indirectly bonded to the oxygen atom of (meth)acrylate, for example, the group shown in the following formula (I) is between the ester Between the oxygen atom and the cyclic ether structure.

-(CH ₂ ) _m -...(I)

(In the formula (I), m represents an integer of 1 to 7.)

The (meth)acrylate (A) is preferably a compound represented by the following formula (1), more preferably a compound represented by the following formula (2).

[In formula (1) and formula (2), R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group with a carbon number of 1 to 10, x represents an integer from 1 to 6, and Y represents a single bond or - O—CH ₂ —, z represents an integer of 0 to 2. ]

In formula (1) and formula (2), in terms of improving the cross-linking density of polymer particles while ensuring the polymerization stability of polymer particles, the upper limit of the carbon number of the alkyl group of ^R is preferably 6, more preferably Preferably it is 3, more preferably 2, and ^R2 is particularly preferably a hydrogen atom; x is preferably 1 to 4; z is preferably 0 or 1, and z is more preferably 0.

For the compound represented by formula (2), for example, glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, glycidyloxy (poly)alkane Glycol (meth)acrylate, methylglycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether.

Among them, glycidyl (meth)acrylate and 4-hydroxybutyl acrylate glycidyl ether are preferred from the viewpoint of increasing the crosslink density of the polymer particles while ensuring the polymerization stability of the polymer particles. .

These compounds may be used alone or in combination of two or more.

In the (meth)acrylic resin, the content of the structural unit derived from (meth)acrylate (A) is preferably 5 to 90% by mass relative to 100% by mass of the total structural units of the (meth)acrylic resin , more preferably 10 to 80% by mass, more preferably 10 to 50% by mass, particularly preferably 10 to 30% by mass.

When the content of the structural unit derived from the (meth)acrylate (A) is within the above range, both the polymerization stability of the polymer particle and the ring-opening polymerization of the cyclic ether moiety by the catalyst can be achieved.

The content of the structural unit derived from (meth)acrylate (A) can be calculated from the quantity of (meth)acrylate (A) in the polymerizable monomer component used at the time of manufacture of (meth)acrylic resin.

"Polymerizable monomer (B)"

The polymer particles of the present invention preferably have a structure derived from the above-mentioned (meth)acrylic resin further including a polymerizable monomer (B) other than the above-mentioned (meth)acrylate (A). By containing the polymerizable monomer (B), the obtained polymer particles have excellent monodispersity and high hardness.

In the step (1), by radically polymerizing the polymerizable monomer (B) together with the (meth)acrylate (A), it is possible to obtain a polymerized compound containing a structure derived from the polymerizable monomer (B). object particles.

The polymerizable monomer (B) is not particularly limited as long as it can be copolymerized with the aforementioned (meth)acrylate (A), and examples thereof include monofunctional monomers such as (meth)acrylic monomers, styrene monomers, and the like. , functional group-containing monomers, conjugated diene-based monomers, polyurethane resin-forming monomers and polyols, etc., preferably selected from the group consisting of monomers having 1 to 4 functional groups in one molecule At least one compound among them is more preferably at least one compound selected from the group consisting of monomers having 1 to 4 (meth)acryl groups in one molecule.

In terms of (meth)acrylic monomers, for example, alkyl (meth)acrylates: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth)acrylate ) butyl acrylate, (methyl) Amyl acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate and ( lauryl methacrylate, etc.,

Aromatic (meth)acrylate: phenyl (meth)acrylate and benzyl (meth)acrylate, etc.,

Alkoxyalkyl (meth)acrylate: Methoxyethyl (meth)acrylate, Ethoxyethyl (meth)acrylate, Propoxyethyl (meth)acrylate, Butyl (meth)acrylate Oxyethyl ester and ethoxypropyl (meth)acrylate, etc.,

Salts such as (meth)acrylic acid and alkali metal (meth)acrylic acid salts;

(Meth)acrylates of alicyclic alcohols: cyclohexyl (meth)acrylate; isobornyl (meth)acrylate, etc.

In terms of styrene-based monomers, for example, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, acrylic Alkylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene; fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, chloromethylstyrene , iodostyrene, nitrostyrene, acetylstyrene, methoxystyrene, α -methylstyrene, vinyltoluene, etc.

In terms of monomers containing functional groups, for example,

唑啉基的聚合性化合物：2-乙烯基-2-

唑啉、2-乙烯基-5-甲基-2-

唑啉及2-異丙烯基-2-

唑啉等， contain

Azoline-based polymerizable compounds: 2-vinyl-2-

Azoline, 2-vinyl-5-methyl-2-

Azoline and 2-isopropenyl-2-

oxazoline, etc.,

Aziridine group-containing polymerizable compounds: (meth)acryl aziridine, (meth)acrylic acid-2-aziridinyl ethyl ester, etc.,

Epoxy-containing vinyl monomers: allyl glycidyl ether, (meth)acrylate glycidyl ether, and (meth)acrylate-2-ethylglycidyl ether, etc.,

Hydroxyl-containing vinyl compounds: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (meth)acrylic acid and poly Monoesters of propylene glycol or polyethylene glycol, adducts of lactones and 2-hydroxyethyl (meth)acrylate, etc.,

Fluorine-containing vinyl monomer: fluorine-substituted alkyl (meth)acrylate, etc.

Carboxyl-containing vinyl monomers: unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid, their salts and their (partial) ester compounds and acid anhydride, etc.,

Reactive halogen-containing vinyl monomers: 2-chloroethyl (meth)acrylate, 2-chloroethyl vinyl ether, monochlorovinyl acetate, vinylidene chloride, etc.,

Vinyl monomers containing amide groups: (meth)acrylamide, N-methylol(meth)acrylamide, N-methoxyethyl(meth)acrylamide, N-butoxy methyl (meth)acrylamide, etc.

Organosilicon-containing vinyl compound monomers: vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine , 2-methoxyethoxytrimethoxysilane, etc.,

Other macromonomers; substances having free-radically polymerizable vinyl groups at the end of copolymers of the above monomers (for example, fluorine-based macromonomers, silicon-containing macromonomers, urethane-based macromonomers body),

Acrylonitrile; Vinyl acetate.

As a conjugated diene monomer, butadiene, isoprene, chloroprene, etc. are mentioned, for example.

As monomers for forming polyurethane resins, polyols mainly composed of ethylene glycol and diisocyanate raw materials, such as 2,4-diisocyanate toluene, 2,6-diisocyanate, etc., can be used. Aromatic diisocyanate such as cresyl ester and p-phenylene diisocyanate, aliphatic diisocyanate, difunctional terminal isocyanate urethane prepolymer, etc.

Examples of polyhydric alcohols include glycol compounds such as ethylene glycol and diethylene glycol, polyether glycols, and the like.

The above-mentioned polymer monomers may be used alone, or two or more kinds thereof may be used.

When the (meth)acrylic resin contains a constitutional unit derived from the polymerizable monomer (B), from the viewpoint of adjusting the polymerization stability and hardness of the obtained polymer particles, relative to the (meth)acrylic resin The content of the structural units derived from the polymerizable monomer (B) is preferably 15 to 90% by mass based on 100% by mass of the total structural units.

The content of the structural unit derived from the polymerizable monomer (B) can be calculated from the amount of the polymerizable monomer (B) in the monomer component used for producing the (meth)acrylic resin.

From the viewpoint of adjusting the hardness of the obtained polymer particles, a polyfunctional monomer can be used as the polymerizable monomer (B) within the range not impairing the effect of the present invention.

In terms of polyfunctional monomers, for example,

Difunctional monomers: ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate Acrylates, polyoxyethylene di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol Di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, divinylbenzene, etc.,

Trifunctional monomers: trimethylolpropane triacrylate, trimethylolethane tri(meth)acrylate, neopentylthritol tri(meth)acrylate, dipenteoerythritol tri(meth)acrylate Esters, Ethoxylated Trimethylolpropane Tri(meth)acrylate, Propoxylated Trimethylolpropane Tri(meth)acrylate, Tris(2-(meth)acryloxyethylisocyanurate )wait,

Four or more functional monomers: neopentylthritol tetra(meth)acrylate, ethoxylated neopentylthritol tetra(meth)acrylate, propoxylated neopentylthritol tetra(meth)acrylate, dineopentyl tetramethacrylate Alcohol tetra(meth)acrylate, B Oxidized Di-Neopentylthritol Tetra(meth)acrylate, Propoxylated Di-Neopentylthritol Tetra(meth)acrylate) Acrylate, Di-Trimethylolpropane Tetra(meth)acrylate, Ethoxylated Di - tetra(meth)acrylate compounds such as trimethylolpropane tetra(meth)acrylate and ethoxylated di-trimethylolpropane tetra(meth)acrylate,

Such as hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate and methylene bis (4-cyclohexyl isocyanate) diisocyanate with aliphatic Diisocyanate compounds, or diisocyanate compounds having aromatic groups such as diisocyanate toluene or 4,4,-diphenylmethane diisocyanate, and by addition reaction with glycidyl di(meth)acrylate The obtained adducts, diperythritol penta(meth)acrylate, dipenteoerythritol hexa(meth)acrylate, and the like.

"Radical Polymerization"

The mother particle containing a (meth)acrylic resin can be obtained by radically polymerizing the said (meth)acrylate (A) and the polymerizable monomer (B) as needed by a well-known method.

Examples of this method include emulsification or suspension polymerization in the presence of a radical polymerization initiator, or swelling polymerization of monomers using non-crosslinked seed particles together with a radical polymerization initiator. (that is, the so-called seed polymerization method), a soap-free emulsion polymerization method, and other polymerization methods in an aqueous medium. Among these polymerization methods, it is preferable to use the seed polymerization method because mother particles having a particle diameter of several μm and having a uniform particle diameter can be obtained.

(radical polymerization initiator)

In terms of radical polymerization initiators that can be used for the above-mentioned polymerization, for example, persulfates such as potassium persulfate and ammonium persulfate; peroxides such as benzoyl peroxide and lauryl peroxide; azobisiso Azo compounds such as butyronitrile. A polymerization initiator may be used individually or in combination of 2 or more types. The usage-amount of a polymerization initiator is preferably 0.1-10 mass parts with respect to 100 mass parts of monomer components.

(emulsifier)

In terms of the above-mentioned emulsifiers that can be used for polymerization, for example, alkylsulfonates such as sodium dodecylsulfonate; alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate; α-sulfonic acid fatty acid ester salts such as 1-methyl tetra-acid sodium; polyethylene glycol alkyl aromatic ethers such as polyethylene glycol nonylphenyl ether; polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether; Salts of polyoxyethylene polycyclic phenyl ether, allyl ether and these sulfates. Among them, alkylbenzenesulfonates are preferred. An emulsifier can be used individually or in combination of 2 or more types. The emulsifier is preferably used in an amount of 0.01 to 20 parts by mass relative to 100 parts by mass of the monomer component.

(dispersion stabilizer)

In terms of the above-mentioned dispersion stabilizers that can be used for polymerization, for example, partially saponified polyvinyl alcohol; fully saponified polyvinyl alcohol; polyacrylic acid, its copolymers and such neutralized products; polymethacrylic acid, its copolymers substances and such neutralized substances; celluloses such as carmellose and hydroxypropylmethylcellulose; polyvinylpyrrolidone. The dispersion stabilizers may be used alone or in combination of two or more. The usage-amount of a dispersion stabilizer is preferably 0.1-10 mass parts with respect to 100 mass parts of monomer components.

As for the above-mentioned aqueous medium that can be used for polymerization, for example, water, a mixture of water and an hydrophilic organic solvent can be mentioned.

As water, purified water (for example: ion-exchanged water, distilled water), underground water, tap water are mentioned, for example.

In terms of hydrophilic organic solvents, for example, lower alcohols such as methanol, ethanol, and isopropanol; polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, and triethylene glycol; Lucus, etc. Cylusus: ketones such as acetone; ethers such as tetrahydrofuran ether; esters such as methyl formate.

The hydrophilic organic solvents may be used alone or in combination of two or more. The addition amount of a hydrophilic organic solvent is 10 mass parts or less normally with respect to 100 mass parts of water. In this specification, unless otherwise specified, "aqueous medium" refers to the above-mentioned medium.

In the above polymerization method, the polymerization temperature is usually 40 to 100°C, preferably 55 to 85°C, and the polymerization time is usually 1 to 24 hours, preferably 1 to 10 hours. In seed polymerization, the above-mentioned polymerization conditions can be employed at each stage.

The seed polymerization system uses a seed (seed) polymerization method during polymerization. The seed polymerization is a kind of emulsion polymerization, and it is preferable to carry out as seed emulsion polymerization. In seeded emulsion polymerization, the nucleation stage in the general emulsion polymerization system can be replaced by a seed. By using seeds with uniform particle size and fully swelling the seeds with monomers before polymerization, resin particles with large particle size and uniform particle size can be obtained.

When obtaining a (meth)acrylic resin by seed polymerization, the above-mentioned (meth)acrylate (A), polymerizable monomer (B) and other monomer components are copolymerized in the presence of a seed (seed) .

From the viewpoint of making the particle size of the (meth)acrylic resin uniform, it is preferable to use monodisperse particles as seeds. For the seed, it is preferable to use the aforementioned polymer of alkyl (meth)acrylate as an example of the monomer component, such as polymethylmethacrylate (PMMA) or particles of polymethacrylate.

The seed polymerization can be repeated many times, usually by performing the seed polymerization 1 to 15 times, preferably 1 to 10 times, to obtain (meth)acrylic resin particles. In addition, when the seed polymerization is repeated, the resin particles obtained by the first seed polymerization are used as the seeds used for the second seed polymerization, and the resin particles obtained by n-1 seed polymerization are similarly , as the seed used for the nth seed aggregation. In addition, the examples of the above-mentioned seeds are examples of seeds used for the first seed polymerization when the seed polymerization is carried out a plurality of times.

The average particle diameter of the seed used for the first seed polymerization, that is, the initial seed polymerization, varies depending on the size desired as the average particle diameter of the (meth)acrylic resin and the number of repetitions of the seed polymerization. , the average particle size usually used is 0.1 to 3.0 μ m, preferably 0.1 to 2.0 μ m seeds.

The seeds are usually 1 to 50 parts by mass, preferably 1 to 30 parts by mass, based on 100 parts by mass of the monomer component. In addition, when seed polymerization is carried out a plurality of times, 1 to 50 parts by mass of seeds are usually used, preferably 1 to 30 parts by mass, per seed polymerization per 100 parts by mass of monomer components.

In addition, the CV value of the seeds is preferably 10% or less, more preferably 2 to 8% with high monodispersity. In addition, the CV value (Coefficient of Variation) is an index of the particle size distribution of the particles, and is also called a value of the coefficient of variation, and can be obtained from the following formula (II).

CV value [%]=(σ/D)×100...(II) [In the formula (II), σ is the standard deviation, and D is the average particle diameter. ]

If the total of (meth)acrylate (A) and polymerizable monomer (B) is 100 parts by mass, the amount of each monomer in the monomer component is preferably (meth)acrylate (A) 5 to 90 parts by mass and 10 to 95 parts by mass of the polymerizable monomer (B), more preferably 10 to 80 parts by mass of (meth)acrylate (A) and 20 to 80 parts by mass of the polymerizable monomer (B). 90 parts by mass, more preferably (meth)acrylate (A) is 10 to 50 parts by mass and polymerizable monomer (B) is 50 to 90 parts by mass, especially (meth)acrylate (A) 10 to 30 parts by mass and 70 to 90 parts by mass of the polymerizable monomer (B). In addition, when the (meth)acrylic resin is obtained by a multi-stage reaction such as seed polymerization, when the total of the monomer components used in each stage is 100 parts by mass, the amount of each monomer used is within the above range That's it.

In step (1), finally, if necessary, the (meth)acrylic resin can be washed and dehydrated with ion-exchanged water using a Buchner funnel or the like.

〈Step (2)〉

In step (2), after step (1), the aforementioned mother particle is brought into contact with an imidazole-based compound or/and an amino compound having a tertiary amino group, so that the cyclic ether positions in the aforementioned cyclic ether structure are mutually ring-opening polymerization, A polymer particle including a (meth)acrylic resin having a structure formed by ring-opening polymerization of cyclic ether moieties.

In the (meth)acrylic resin, the structure formed by the ring-opening polymerization of the cyclic ether parts in the cyclic ether structure may be one of the ring-opening polymerization of the cyclic ether parts in the above-mentioned cyclic ether structure, or may be Two or more different cyclic ether moieties are mutually ring-opened and polymerized.

As a structure formed by ring-opening polymerization of cyclic ether parts, the repeating unit represented by following formula (3), for example is mentioned.

[In formula (3), P ¹ represents a polymer chain comprising a structural unit derived from (meth)acrylate (A). ]

For example, when glycidyl methacrylate is used as a polymerizable monomer, the structure formed by ring-opening polymerization of cyclic ether moieties is a structure represented by the following formula (4). In this case, the cyclic ether moieties of the glycidyl methacrylate polymer, that is, the epoxy groups are ring-opened and polymerized. Therefore, the obtained polymer particle has the repeating structure of the glycidyl methacrylate polymer chain in the step (1), and the epoxy groups of the glycidyl methacrylate in the step (2) are ring-opened with each other. Polymerized repeating structures.

The content of structural units formed by ring-opening polymerization of the cyclic ether moieties in the cyclic ether structure in the (meth)acrylic resin relative to 100% by mass of the total structural units of the (meth)acrylic resin is preferable It is 5 to 90 mass %, More preferably, it is 10 to 80 mass %, More preferably, it is 10 to 50 mass %, Most preferably, it is 10 to 30 mass %.

When the content of the structure formed by ring-opening polymerization of cyclic ether moieties is within the above range, polymer particles having high hardness and excellent monodispersity can be obtained.

"Imidazole Compounds"

The polymer particle of the present invention preferably contains a (meth)acrylate (A) having a cyclic ether structure that is polymerized and an imidazole-based compound is added to a part of the cyclic ether structure to make the cyclic ether part A (meth)acrylic resin with a ring-opened structure.

Examples of imidazole-based compounds include imidazole-based compounds having an active hydrogen at the 1-position represented by the following formula (5) and imidazole-based compounds having no active hydrogen at the 1-position represented by the following formula (6).

[In formula (5) and formula (6), R ³ and R ⁶ represent an organic group, R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group with 1 to 20 carbons. ]

For the imidazole compound having an active hydrogen at the 1 position represented by formula (5), for example, 2-ethyl-4-methylimidazole, 2-phenyl-1H-imidazole, 2-methylimidazole, 4- Methyl-1H-imidazole-5-carboxylic acid ethyl ester, 2-isopropylimidazole, 1H-imidazole-4,5-dicarboxylic acid, benzimidazole, 2-phenyl-5-benzimidazolesulfonic acid, 2-hydroxybenzimidazole, 4-methylimidazole, 5,6-dimethylbenzimidazole.

The imidazole compound having no active hydrogen at the 1-position represented by the formula (6) includes, for example, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl] -1,3,5-triazine, 1-isobutyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazolium‧trimellitate, 1,2-dimethylimidazole , 1-benzyl-2-methylimidazole, 2-phenyl-1-benzyl-1H-imidazole.

Among the above imidazole compounds, 2-ethyl-4-methylimidazole is preferred from the viewpoint of reactivity and water solubility.

The above imidazole compounds may be used alone or in combination of two or more.

With respect to 100 parts by mass of the solid content of the mother particles, the amount of the imidazole compound added in step (2) is 0.01 to 5.0 parts by mass, preferably 0.05 to 3.0 parts by mass, more preferably 0.1 to 2.0 parts by mass.

The molecular weight of the imidazole compound is preferably from 50 to 1000, more preferably from 50 to 500, and still more preferably from 50 to 300.

In step (2), when using an imidazole-based compound having an active hydrogen at the 1-position, the imidazole-based compound binds to a part of the side chain cyclic ether of the (meth)acrylic resin due to the active hydrogen of the imidazole-based compound. reaction, an imidazole-based compound can be added to a part of the ring-opened site of the cyclic ether structure.

The structure in which an imidazole-based compound is added to a part of the aforementioned cyclic ether structure to open the ring of the cyclic ether structural part includes, for example, a structure shown in the following formula (7), which has A structure in which an active hydrogen imidazole compound reacts with a cyclic ether in a part of the side chain of a (meth)acrylic resin to open the ether ring and add an imidazole compound.

[In formula (7), R ³ represents an organic group, R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group with 1 to 20 carbons, P ² represents the main chain of a (meth)acrylic resin, w Represents an integer from 1 to 6. ]

A structure obtained by adding an imidazole compound to a part of the aforementioned cyclic ether structure to open the ring of the cyclic ether portion may be in the same molecule as the (meth)acrylic polymer, or may be the same molecule as the aforementioned (meth)acrylic acid. Among the molecules of different (meth)acrylic polymers, the aforementioned (meth)acrylic polymer is a (meth)acrylic polymer having a structure formed by ring-opening polymerization of the aforementioned cyclic ether moieties. Resin.

When the polymer particle of the present invention has a structure in which an imidazole compound is added to a part of the cyclic ether structure to open the ring of the cyclic ether part, in the ring-opening polymerization of the cyclic ether parts, the reaction with the reacted cyclic From the viewpoint of the balance of the amount of ether moieties, the content of structural units obtained by adding an imidazole-based compound to ring-open the cyclic ether moieties is preferably 5% with respect to 100% by mass of the total structural units of the polymer particles. to 90% by mass. More preferably, it is 10 to 80 mass %, More preferably, it is 10 to 50 mass %, Most preferably, it is 10 to 30 mass %.

"Amino compounds with tertiary amine groups"

For the amino compounds with tertiary amino groups, for example, trimethylamine, triethylamine, tributylamine, trioctylamine, N-methylmorphine, N-ethylmorphine, N, N- Dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-methyldiethanolamine, N-n-butyldiethanolamine, N-tert-butyldiethanolamine, N,N - Diethylisopropanolamine, 1-methylimidazole, 1,8-diacribicyclo[5.4.0]undec-7-ene, polyethyleneimine.

Among them, from the viewpoint of ring-opening polymerization of cyclic ether parts to obtain polymer particles having both monodispersity and high hardness, it is preferable that the compound does not have primary and/or secondary amine groups in the molecule, Amino compounds with only tertiary amine groups.

A compound having a tertiary amine group is different from a compound having a primary amine group or a secondary amine group, and acts as a polymerization catalyst to advance the reaction. The tertiary amine formed after the reaction of the amine compound with the 1st or 2nd amine group and the cyclic ether group is difficult to have a catalytic function because of its steric hindrance, but the compound with the 3rd amine group is the strongest It is basic and has a catalytic function, so it can make ring-opening polymerization of cyclic ether moieties.

In step (2), relative to 100 parts by mass of the solid content of the mother particle, the amount of the amino compound having a tertiary amino group is 0.01 to 5.0 parts by mass, preferably 0.05 to 3.0 parts by mass, more preferably 0.1 to 3.0 parts by mass. 2.0 parts by mass.

The average molecular weight of the amino compound having a tertiary amino group is preferably from 50 to 2000, more preferably from 50 to 500, and still more preferably from 50 to 200.

In step (2), one or more imidazole-based compounds or amino-based compounds with tertiary amine groups can be used respectively, and the aforementioned imidazole-based compounds and amino compounds with tertiary amine groups can also be used in combination within the scope of not impairing the effect of the present invention. based amino compounds. Among them, it is preferable to use an imidazole-based compound because the hardness of the polymer particles can be increased.

"Other Ingredients"

In the step (2), other components may be used in combination with the aforementioned imidazole-based compound or the amino compound having a tertiary amino group as needed. Other components include, for example, an amino compound having a primary amino group and/or an amino compound having a secondary amino group.

Amino compounds with primary amine groups can be exemplified by

Alkyl diamine;

Menthane diamine (MDA: Menthene Diamine), isophorone diamine, xylylene diamine, diethylenetriamine (containing 2-level amine), trimethyltetramine (containing 2-level amine), tetraethylenepentamine ( Contains 2-level amine), 1,3-bis(aminomethyl)cyclohexane, diethylaminopropylamine, 4,4'-methylenebis(2-methylcyclohexylamine) and other alicyclic amines;

Aromatics such as m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylene, 4,4'-diaminodiphenylether, 1,3-bis(3-aminophenoxy)benzene amine.

Amino compounds with secondary amine groups can be exemplified by

Methylcyclohexylamine, diethylenetriamine (containing primary amine), trimethyltetramine (containing primary amine), tetraethylenepentamine (containing primary amine);

Aromatic amines such as 4,4'-methyleneaniline.

When using a compound with a primary amino group and/or a secondary amino group, the amount of the compound with a primary amino group and/or a secondary amino group is preferably 0.7 relative to 100 parts by mass of the solid content of the mother particle. Parts by mass or less.

When the amount used is not more than the above value, the cyclic ether sites of (meth)acrylate (A) can be ring-opened without impairing the catalytic effect of the imidazole compound or the amino compound having a tertiary amino group. polymerization.

When the amount used exceeds the above range, the addition reaction between the cyclic ether portion existing on the surface of the polymer particle and the primary amine group and/or the secondary amine group will occur, and a part of the cyclic ether will not react and complete hardening question.

In step (2), when using an imidazole-based compound having an active hydrogen at the 1-position, it is believed that after the imidazole-based compound is added to a part of the ring-opened part of the cyclic ether structure, the imidazole-based compound becomes a catalyst to promote Ring-opening polymerization of cyclic ether moieties of mother particles.

On the other hand, when an imidazole compound or an amino compound having a tertiary amine group without an active hydrogen at the 1-position is used in step (2), it is believed that the imidazole compound or an amine compound having a tertiary amine group It is not added to a part of the cyclic ether structure, but acts as a catalyst to promote the ring-opening polymerization of the cyclic ether parts of the mother particle.

In these ring-opening polymerizations, relative to the (meth)acrylate (A) having a cyclic ether structure, the molar ratio of the imidazole compound or the amino compound having a tertiary amino group (the imidazole compound or the amine compound having a tertiary Amino compound/(meth)acrylate having a cyclic ether structure (A)) is preferably 0.001 to 0.4, more preferably 0.002 to 0.2. Since the imidazole compound and the amino compound having a tertiary amino group act as catalysts for ring-opening polymerization of cyclic ether moieties, the anionic polymerization reaction sufficiently proceeds when the molar ratio is within the above range. The ring-opening polymerization can be performed, for example, at 100 to 200° C. for 0.5 to 2 hours.

〈Step (3)〉

In step (3), the polymer particles obtained in step (2) are powdered.

The method for isolating the polymer particles from the dispersion medium is not particularly limited, and known methods such as filtration and centrifugation can be used. Then, the separated polymer particles can be dried and powderized by using a generally employed method such as a freeze-drying method, a spray-drying method, or the like.

Considering the hardness of the polymer particles, it is better to dry under the condition that the particles are not deformed. The dried polymer particles are preferably pulverized with a mortar, jet mill or the like.

[Physical properties of polymer particles]

Although the polymer particles of the present invention are not particularly limited, the average particle diameter is preferably 2 to 20 μm , more preferably 2 to 5 μm . When the average particle diameter is less than the aforementioned range, there is a possibility that polymer particles tend to aggregate. In addition, in this specification, all "average particle diameters" including the average particle diameter used for the calculation of the CV value or 10%K value of a polymer particle can be calculated|required by the measuring method described in an Example.

The CV value of the polymer particles is preferably at most 15%, more preferably at most 7%. When the CV value is out of the aforementioned range, the properties in various uses of the polymer particles tend to decrease. For example, when polymer particles are used for conductive particles constituting an anisotropic conductive adhesive, connection reliability tends to decrease. In addition, the CV value of a particle diameter can be calculated|required by the method similar to description of the CV value of the said seed.

The 10% K value of the polymer particles of the present invention obtained by the following formula is preferably 3,000 to 7,000 N/mm ² , more preferably 3,300 to 6,000 N/mm ² .

10% K value (N/mm ² )=(3/√2)‧F‧S ^-3/2 ‧R ^-1/2

[F and S are the load value (N) and compression displacement (mm) of the polymer particles under 10% compression deformation respectively, and R is the radius (mm) of the polymer particle, which is measured by the method described in the examples half of the average particle diameter of the polymer particles. ]

If the 10%K value of the polymer particles is too small, when used as an anisotropic conductive material, the binder (adhesive) around the conductive particles cannot be fully removed (cannot be pushed), and the If the condition is weak, the contacts will fall off, etc., and a low connection resistance value may not be obtained. On the other hand, if the 10%K value of the polymer particles is too large, although the true contact area involved in electron conduction increases and the resistance value decreases, the joint part is damaged and a good electrical contact state cannot be ensured.

The 10% K value is a value calculated from the compressive load when the particle size is deformed by 10%, and generally and quantitatively expresses the hardness of the sphere. The specific measurement method of the 10% K value is described in the Examples described later.

The polymer particles of the invention are preferably those which, when compressed, break up before the maximum load is reached, ie have a so-called break point.

As a method of obtaining polymer particles having breakage points, for example, a method of forming a three-dimensional network structure in the obtained polymer includes a polyfunctional monomer as a polymer constituting the polymer particles. In addition, for example, even when the polymer is composed of only monofunctional monomers, the uncrosslinked polymer can be made A method in which ring-opening polymerization of epoxy groups is carried out.

[Use of Polymer Particles]

The use of the polymer particles of the present invention is not particularly limited, and for example, it can be used for modifying the lubricity of various spacers and resin films in addition to the field of electric/electronic materials such as conductive particles for anisotropic conductive adhesives additives for rheology control, blasting agents, abrasives, carriers for chromatography, etc. From the viewpoint of exhibiting the effects of the present invention, the polymer particles of the present invention are preferably applied to polymer particles serving as the core of conductive particles used in anisotropic conductive adhesives.

<Heterotropic Conductivity Adhesive>

When the polymer particle of the present invention is used in an anisotropic conductive adhesive, conductive particles can be obtained by providing a conductive metal layer on the surface of the polymer particle. The method for forming the metal layer on the surface of the polymer particles is not particularly limited, for example, by electroless plating, coating will separate metal fine powder or A method of coating a paste mixed with a binder, and physical deposition methods such as vacuum deposition, ion plating, and ion sputtering. More specifically, the method described in Japanese Unexamined Patent Application Publication No. 2000-319309 may be mentioned.

The anisotropic conductive adhesive only needs to contain the aforementioned conductive particles and binder resin, and other components are not particularly limited, and components conventionally included in anisotropic conductive adhesives can be used without particular limitation.

The binder resin is not particularly limited as long as it is an insulating resin, and examples thereof include thermoplastic resins such as acrylic resins, ethylene/vinyl acetate resins, and styrene/butadiene block copolymers. A curable resin composition cured by the reaction of a monomer or oligomer of oxypropyl group and a curing agent such as isocyanate, a curable resin composition cured by light or heat, or the like.

In addition, depending on the method of producing the adhesive, the anisotropic conductive adhesive can be in the form of a film or a paste, and the dispersion method can be appropriately changed according to the form. The film-like anisotropic conductive adhesive (anisotropic conductive film) is obtained by molding a mixture of conductive particles dispersed in the resin component into a film; the anisotropic conductive paste is adjusted and anisotropic conductive with a solvent The viscosity of the mixture obtained in the same way as the film is obtained.

When the polymer particles of the present invention are used in an anisotropic conductive adhesive, the anisotropic conductive adhesive preferably contains 5 to 60 parts by mass of polymer particles, more preferably 10 to 50 parts by mass of the polymer particles per 100 parts by mass of the anisotropic conductive adhesive. If the content of the conductive particles is too small, it may be difficult to obtain sufficient conductivity. On the other hand, if the content of the conductive particles is too large, the conductive particles will contact each other, and it may be difficult to function as an anisotropic conductive material. situation.

The anisotropic conductive adhesive can be obtained, for example, by mixing or kneading at least conductive particles and an adhesive, but usually can be obtained by mixing or kneading conductive particles, adhesive, hardener, and organic solvent .

[Example]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the description of the following Examples and the like, "parts" means "parts by mass" unless otherwise specified.

[The average particle size]

The average particle diameter of the polymer particles obtained in Examples and Comparative Examples is the particle diameter at the time of effective analysis number: 30,000 using a laser diffraction particle size distribution analyzer FPIA-3000S (manufactured by Spectris Co., Ltd.). The average value (cumulative 50% particle diameter when set as a volume basis) is set as the average particle diameter.

[CV value]

The CV values of the polymer particles obtained in Examples and Comparative Examples were obtained from the following formula.

CV value (%)=standard deviation of particle size distribution/average particle size×100

[10% K value]

平壓頭，使用附屬於裝置上的顯微鏡，選擇1個直徑3.0μm的聚合物粒子，在最大負荷50mN、負荷速度1.33mN/秒的條件下壓縮聚合物粒子，測定粒徑變形10%時的壓縮負荷F(N)，由下式求出。 The 10% K value of the polymer particles obtained in the examples and comparative examples was determined using an Ultra Micro Indentation Hardness Tester (Ultra Micro Indentation Hardness Tester) ENT-NEXUS (manufactured by ELIONIX Co., Ltd.) at 25°C. Front mounted 50 μm

Flat indenter, using the microscope attached to the device, select a polymer particle with a diameter of 3.0μm, compress the polymer particle under the conditions of a maximum load of 50mN and a loading speed of 1.33mN/second, and measure the particle diameter deformation of 10%. The compression load F(N) is obtained from the following formula.

10% K value (N/mm ² )=(3/√2)‧F‧S ^-3/2 ‧R ^-1/2

[F and S are the load value (N) and compression displacement (mm) of the polymer particles under 10% compression deformation respectively, and R is the radius (mm) of the polymer particle, which is measured by the method described in the examples half of the average particle diameter of the polymer particles. ]

[break point]

Using the same testing machine as the measurement of the aforementioned 10% K value, if the particle is compressed and the particle breaks before reaching the maximum load, it is set as "existing" breaking point. The rupture point is used as an indicator of the crosslinking of the polymers by the ring-opening polymerization of the epoxy groups proceeding by adding a catalyst after the uncrosslinked polymer constituting the polymer particle by adding a catalyst after a tertiary amine or imidazole. In addition, "none" described in the column of the breaking point in Table 1 and Table 2 means that there is no corresponding data.

[IR(910cm ^-1 )]

The peak near 910cm ^-1 was observed by infrared absorption spectroscopy (IR). Due to the disappearance of the peak, it was confirmed that all the epoxy groups in the polymer particles were reacted by the addition reaction of the amine compound or the ring-opening of the epoxy groups. polymerize and react. In addition, the symbol "-" in the column of IR (910cm ^-1 ) in Table 1 and Table 2 means that there is no corresponding data, and "residual" means that the peak remains, that is, part of the polymer constituting the polymer particle. The epoxy group exists as an epoxy group without undergoing an addition reaction with an amine compound or without ring-opening polymerization.

Each evaluation result is shown in Table 1 and Table 2.

[Example 1]

<step 1)>

(Phase 1 Polymerization: Manufacture of Monodisperse Particles)

Put 100 parts of methyl methacrylate (hereinafter also referred to as "MMA") and 300 parts of ion-exchanged water into a four-necked flask with a volume of 1 liter equipped with a thermometer and a nitrogen gas inlet tube, mix and stir, and put the The temperature was raised to 80° C. while stirring to obtain a mixed liquid. 0.5 part of potassium persulfate was added to the heated mixed solution and reacted for 6 hours while maintaining 80° C. to obtain a dispersion (A1) of polymethyl methacrylate (PMMA) resin particles.

The PMMA resin particles obtained by separating/drying from the dispersion liquid (A1) are positive spherical monodisperse particles with an average particle diameter of 0.4 μm and a CV value of 3.5%. The solid content concentration in the dispersion liquid (A1) was 24% by mass.

(Phase 2 Aggregation: Seed Aggregation)

100 parts of methyl methacrylate and 1.0 parts of benzoyl peroxide as an initiator were put into a 1-liter flask and dissolved to obtain a solution. Add 0.5 parts of sodium dodecylbenzenesulfonate and 300 parts of ion-exchanged water to the aforementioned solution, and emulsify with a high-speed emulsifier to obtain an emulsion.

Next, the dispersion liquid (A1) of the said PMMA resin particle was added to the said emulsion liquid so that the PMMA resin particle amount might become 6.4 parts.

After the mixture was swelled at 50°C for 1 hour, water in which partially saponified polyvinyl alcohol was dissolved was added (the sum of the dispersion stabilizer and water was 40 parts), and the reaction was carried out at 73°C for 1.5 hours, followed by 1.5 hours at 90°C. After cooling for 1 hour, a dispersion (A2) of monodisperse seed particles with an average particle diameter of 1.0 μm and a CV value of 3.5% was obtained.

(Polymerization in the third stage: production of (meth)acrylic resin particles)

66.3 parts of methyl methacrylate, 30 parts of glycidyl methacrylate (GMA), and 1.0 parts of benzoyl peroxide as an initiator were put into a 1-liter flask and dissolved to obtain a solution. 0.5 parts of sodium dodecylbenzenesulfonate and 200 parts of ion-exchanged water were put into the aforementioned solution, and emulsified with a high-speed emulsifier to obtain an emulsion.

Next, the dispersion liquid (A2) of the aforementioned monodisperse seed particles was added to the aforementioned emulsion liquid so that the amount of seed particles became 3.7 parts.

After swelling the mixture at 50°C for 1 hour, add water in which partially saponified polyvinyl alcohol was dissolved (the sum of the dispersion stabilizer and water is 40 parts), react at 73°C for 1.5 hours, and then react at 90°C After reacting for 1.5 hours, cooling was performed to obtain a dispersion (A3) of (meth)acrylic resin particles having an average particle diameter of 2.8 μm and a CV value of 5.2%.

〈Step (2)〉

(Contact of imidazole compounds and ring-opening polymerization of cyclic ether moieties)

1 part of 2-ethyl-4-methylimidazole (hereinafter also referred to as "2E4MZ") as an epoxy polymerization catalyst was added to the dispersion (A3) obtained above to make the imidazole The compound is in contact with the parent particles. Then, by heating at 180 degreeC for 1 hour, the dispersion liquid (A4) containing the (meth)acrylic resin which has the structure which ring-opened and polymerized the cyclic ether part of the said (meth)acrylic resin particle was obtained.

〈Step (3)〉

(powder)

The above-mentioned dispersion (A4) was turned into powder by freeze-drying, and then the powder was further pulverized with a mortar and a jet mill to obtain a structure including ring-opening polymerization of cyclic ether moieties having the above-mentioned monodisperse seed particles. Polymer particles of (meth)acrylic resin.

[Examples 2 to 16, Comparative Examples 1 to 13]

The kind and usage-amount of each component used were changed as described in Table 1 and Table 2, and it carried out similarly to Example 1, and obtained the polymer particle.

[Comparative Example 14]

Since the boiling point of n-butylamine used as an amine-based hardener is about 75°C, in the above <step (2)>, in addition to using n-butylamine to replace 2-ethyl-4-methylimidazole, the temperature Except having set it as 60 degreeC, it carried out similarly to Example 1, and obtained the polymer particle.

[Table 1]

[Table 2]

The symbol meanings of each component in Table 1 and Table 2 are as follows.

(seed)

‧PMMA: polymethyl methacrylate

(radical polymerizable monomer)

[(Meth)acrylate (A)]

‧GMA: Glycidyl methacrylate (light acrylate, manufactured by Kyoeisha Chemical Co., Ltd.)

‧4HBAGE: 4-hydroxybutyl acrylate glycidyl ether (manufactured by Mitsubishi Chemical Corporation)

[Monofunctional monomer]

‧MMA: methyl methacrylate

‧MAA: Methacrylic acid

[Difunctional monomer]

‧EGDMA: Ethylene glycol dimethacrylate

[Trifunctional monomer]

‧TMPTA: Trimethylolpropane triacrylate (Viscoat#295, Osaka Organic Chemical Co., Ltd. limited company)

[Tetrafunctional Monomer]

‧PETA: Neopentylthritol tetraacrylate (M-305, manufactured by Toagosei Co., Ltd.)

(Catalyst added after ring-opening polymerization of cyclic ether)

‧DBU: 1,8-Diacridinebicyclo[5.4.0]undec-7-ene (manufactured by San-Apro Co., Ltd., molecule Quantity=152.24)

‧SP-003: Polyethyleneimine (mixed amines from grades 1 to 3 (amine ratio: grade 1: 45%, grade 2: 35%, grade 3: 20%), EPOMIN SP-003, Nippon Shokubai Co., Ltd. system, number average molecular weight=300)

‧2PZ-PW: 2-phenyl-1H-imidazole (CUREZOL 2PZ-PW, manufactured by Shikoku Chemical Industry Co., Ltd., molecular weight=144.17)

‧2MZA-PW: 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine (CUREZOL 2MZA-PW, Shikoku Chemicals Industrial (Co., Ltd.) system, molecular weight = 219.25)

‧jER Cure IBMI12: 1-isobutyl-2-methylimidazole (jER Cure IBMI12, manufactured by Mitsubishi Chemical Corporation, molecular weight=138.21)

‧2E4MZ: 2-ethyl-4-methylimidazole (molecular weight=110.16)

(amine hardener)

‧jER Cure 113: 4,4'-methylenebis(2-methylcyclohexylamine) (jER Cure 113, manufactured by Mitsubishi Chemical Corporation)

‧NISSAN AMINE M-14: 1-amino-3-undecyloxy-propane (NISSAN AMINE M-14, manufactured by NOF Corporation)

‧Butylamine: n-Butylamine

In the column of "crosslinked type of polymer particles" in Table 1 and Table 2, "uncrosslinked" refers to polymer particles composed only of monofunctional monomers including (meth)acrylate (A) . "Crosslinking" refers to polymer particles composed of a monofunctional monomer containing (meth)acrylate (A) and a polymerizable monomer containing a polyfunctional monomer as the polymerizable monomer (B).

In the column of "post-added catalyst for ring-opening polymerization of cyclic ether" in Table 1, "H" means active hydrogen in the imidazole-based compound. "H×0" means that there is no active hydrogen in the imidazole-based compound, and "H×1" means that there is one active hydrogen in the imidazole-based compound.

In Table 1 and Table 2, "NH ₂ " refers to imidazole-based compounds or amines used in Examples and Comparative Examples in the columns of "post-added catalyst for ring-opening polymerization of cyclic ether" and "amine-based hardener". It is the primary amine group in the hardener. For example, in the case of "NH ₂ ×1", it means that there is one primary amine group in the imidazole-based compound or amine-based hardener.

As shown in Table 1, the polymer particles in each example had high hardness and excellent monodispersity.

In Example 11, the reason for the rupture point "None" is believed to be that the reaction to epoxy groups is high due to the use of post-addition catalysts of amine compounds that belong to the mixture of 1-3 amine groups. The addition reaction between primary and secondary amine groups and epoxy groups is only carried out near the surface of the polymer particles, so the uncrosslinked polymers inside the particles do not undergo ring-opening polymerization of epoxy groups, but directly form uncrosslinked polymers. The form of the polymer remains.

In Comparative Examples 9 to 11, it is believed that the reason why the fracture point "has" is because a large amount of bifunctional or higher monomers were used to form a network polymer having a three-dimensional network structure.

In Comparative Example 12, the reason why IR (910cm ^-1 ) is "residual" is believed to be because the addition reaction between the primary amine and the epoxy group proceeds preferentially, but the primary amine containing The tertiary amine formed by the addition of the amine compound is difficult to have a catalytic reaction due to steric hindrance, so a part of the epoxy group remains without reacting. In addition, if the addition amount of the amino compound having a primary amino group in Comparative Example 12 is 0.04 equivalent to the epoxy group of GMA, it is because it is different from the addition reaction with the epoxy group when the amine hardener is usually used. The addition amount (for example, the molar ratio of the cyclic ether structure in the masterbatch to the amine hardener is usually about 0.5 to 5) is relatively small, so it is considered that some unreacted epoxy groups remain. For the reasons described above, the 10%K value is considered to be low because the polymer particles of Comparative Example 12 do not have a structure in which ether moieties in GMA are ring-opened and polymerized.

NISSAN AMINE M-14, which is an amine hardener used in Comparative Example 13, is a compound having a primary amine group. The n-butylamine-based compound of the amine-based curing agent used in Comparative Example 14 has a low-molecular-weight primary amine group. In Comparative Examples 13 and 14, the same as Comparative Example 12, because by The tertiary amine group formed by the addition of the compound having the primary amine group does not have a catalytic function for the ring-opening polymerization of epoxy groups, so it is believed that it does not contribute to the improvement of the hardness of the polymer particles.

Claims (8)

A polymer particle comprising a (meth)acrylic resin having a (meth)acrylate (A) having a cyclic ether structure polymerized and having the cyclic ether structure A structure formed by ring-opening polymerization of mesocyclic ether moieties. The polymer particle according to claim 1, wherein the (meth)acrylic resin further contains a polymerizable monomer (B) derived from the (meth)acrylate (A) having a cyclic ether structure Structure. The polymer particle according to claim 2, wherein the polymerizable monomer (B) is at least one selected from the group consisting of monomers having 1 to 4 (meth)acryl groups in one molecule. 1 compound. The polymer particle according to claim 1, wherein the (meth)acrylate (A) having a cyclic ether structure is a compound represented by the following formula (1),

[In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group with 1 to 10 carbons, x represents an integer from 1 to 6, Y represents a single bond or -O-CH ₂ - , z represents an integer from 0 to 2]. The polymer particle according to claim 1, which comprises a (meth)acrylic resin having a polymeric (meth)acrylic acid ester (A) having a cyclic ether structure. A structure in which an imidazole compound is added to a part of the ring-opened part of the aforementioned cyclic ether structure. The polymer particle according to claim 1, wherein in the polymer particle, the 10% K value is 3,000 to 7,000 N/mm ² . A method for producing polymer particles as claimed in any one of claims 1 to 6, comprising: In step (1), the polymerizable monomer component comprising (meth)acrylic acid ester (A) having a cyclic ether structure is subjected to radical polymerization to obtain mother particles comprising (meth)acrylic resin; Step (2) is to make the above-mentioned mother particles contact with the imidazole compound or/and the amino compound with a tertiary amino group, and make the ring-opening polymerization of the cyclic ether parts in the above-mentioned cyclic ether structure to obtain a compound containing (methyl ) polymer particles of acrylic resin, wherein the (meth)acrylic resin has a structure formed by ring-opening polymerization of cyclic ether moieties; and Step (3) is to powderize the aforementioned polymer particles. The polymer particle according to any one of claims 1 to 6, which is used as a conductive particle of an anisotropic conductive adhesive.