JP2012072383A - Curable composition and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which can be cured quickly, and whose cured material has a high adhesive strength to a connection target member; and to provide a connection structure using the curable composition.SOLUTION: The curable composition includes a curable compound having a thiirane group, a thermosetting agent, and a phenolic compound. The connection structure 1 comprises a first connection target member 2, a second connection target member 4, and a connection part 3 connecting the first and second connection target members 2 and 4. The connection part 3 is formed of the curable composition.

Description

  The present invention relates to a curable composition, and more particularly to a curable composition containing a curable compound having a thiirane group as a thermosetting compound, and a connection structure using the curable composition.

  The epoxy resin composition has high adhesive strength of the cured product after curing, and is excellent in water resistance and heat resistance of the cured product. For this reason, epoxy resin compositions are widely used in various applications such as electricity, electronics, architecture, and vehicles.

  Moreover, in order to electrically connect various connection object members, conductive particles may be blended in the epoxy resin composition. The epoxy resin composition containing conductive particles is called an anisotropic conductive material.

  Specifically, the anisotropic conductive material is used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. For example, after an anisotropic conductive material is arranged between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be connected by heating and pressurizing.

  As an example of the anisotropic conductive material, Patent Document 1 below discloses a curing agent that generates free radicals upon heating, a hydroxyl group-containing resin having a molecular weight of 10,000 or more, a phosphate ester, a radical polymerizable substance, a conductive material. An anisotropic conductive material containing conductive particles is disclosed. Specific examples of the hydroxyl group-containing resin include polymers such as polyvinyl butyral resin, polyvinyl formal, polyamide, polyester, phenol resin, epoxy resin, and phenoxy resin.

  Patent Document 2 below discloses an anisotropic conductive material containing a curable component, a silane compound, and conductive particles. Here, it is described that a sufficient adhesive strength can be obtained by the combined use of the curable component and the silane compound, and a stable adhesive strength can be obtained even in a high temperature and high humidity environment.

JP 2005-314696 A JP 2006-16580 A

  In recent years, in the field of precision electronic equipment, the density of circuits has been increasing, and the electrode width and electrode interval have become extremely narrow. For this reason, in the conventional anisotropic conductive materials as described in Patent Documents 1 and 2, the curing does not proceed quickly, and the wiring may fall off, peel off, or be displaced.

  Moreover, although patent document 2 describes that sufficient adhesive strength is obtained, the problem that the adhesive strength of the cured | curing material of anisotropic conductive material with respect to adhesion target members, such as various board | substrates, does not necessarily become high enough. There is.

  An object of the present invention is to provide a curable composition that can be cured quickly and can further increase the adhesive strength of a cured product to a connection target member, and a connection structure using the curable composition. That is.

  According to a wide aspect of the present invention, a curable composition is provided that includes a curable compound having a thiirane group, a thermosetting agent, and a phenolic compound.

  In another specific aspect of the curable composition according to the present invention, a curable compound having an epoxy group different from the curable compound having a thiirane group is further included.

  In still another specific aspect of the curable composition according to the present invention, a compound having a (meth) acryloyl group and a photopolymerization initiator are further included.

  In another specific aspect of the curable composition according to the present invention, the content of the phenolic compound is 0.1 to 20% by weight in 100% by weight of the curable composition.

  In another specific aspect of the curable composition according to the present invention, conductive particles are further included, and the curable composition is an anisotropic conductive material.

  The connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection portion that connects the first and second connection target members. Is formed by a curable composition constructed according to the present invention.

  In a specific aspect of the connection structure according to the present invention, the curable composition is an anisotropic conductive material including conductive particles, and the first and second connection target members are the conductive particles. Are electrically connected.

  Since the curable composition concerning this invention contains the curable compound which has a thiirane group, a thermosetting agent, and a phenolic compound, it can be hardened rapidly. Furthermore, the hardened | cured material which hardened the curable composition concerning this invention has high adhesive strength with respect to a connection object member. Therefore, by using the curable composition according to the present invention, a connection structure having excellent connection reliability can be obtained.

FIG. 1 is a partially cutaway cross-sectional view schematically showing a connection structure using a curable composition according to an embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

(Curable composition)
The curable composition according to the present invention includes a curable compound having a thiirane group, a thermosetting agent, and a phenolic compound. By adopting this composition, the curable composition can be quickly cured, and the adhesive strength of the cured product to the connection target member can be increased.

[Thermosetting compound]
The curable composition concerning this invention contains the curable compound which has a thiirane group as a thermosetting compound. The curable compound having a thiirane group is a thermosetting compound. As for the curable compound which has a thiirane group, only 1 type may be used and 2 or more types may be used together.

  The curable compound having a thiirane group may have an epoxy group. That is, the curable compound having a thiirane group may be a curable compound having a thiirane group and an epoxy group.

  The curable composition according to the present invention may contain a curable compound having an epoxy group different from the curable compound having a thiirane group, in addition to the curable compound having a thiirane group. That is, the curable composition according to the present invention may contain a curable compound having no thiirane group and having an epoxy group in addition to the curable compound having a thiirane group. The curable compound having an epoxy group is a thermosetting compound. As for the curable compound which has an epoxy group, only 1 type may be used and 2 or more types may be used together.

  When the curable compound having a thiirane group is a curable compound having a thiirane group and an epoxy group, the curable composition according to the present invention, in addition to the curable compound having a thiirane group and an epoxy group, It may contain a curable compound having the above-mentioned epoxy group different from the curable compound having a thiirane group and an epoxy group, that is, a curable compound having no thiirane group and having an epoxy group.

  The curable compound having a thiirane group is an episulfide compound. The curable compound having an epoxy group is an epoxy compound. The curable compound having an epoxy group and a thiirane group is a thiirane group-containing epoxy compound.

  By using a curable compound having a thiirane group, the curable composition can be rapidly cured at a low temperature. From the viewpoint of enhancing the storage stability and handleability of the curable composition, the curable composition preferably contains a curable compound having a thiirane group and a curable compound having an epoxy group.

  In 100% by weight of the thermosetting compound, the content of the curable compound having a thiirane group is preferably in the range of 0.1 to 100% by weight. In 100% by weight of the thermosetting compound, the content of the curable compound having a thiirane group is more preferably 5% by weight or more, still more preferably 10% by weight or more, and particularly preferably 50% by weight or more. Since the curable compound having a thiirane group has a thiirane group, the reactivity is higher than that of the curable compound having an epoxy group. Therefore, the higher the content of the curable compound having a thiirane group, the more rapidly the curable composition can be cured at a low temperature.

  When only the curable compound having a thiirane group is used as the thermosetting compound, the “thermosetting compound 100 wt%” indicates 100 wt% of the curable compound having a thiirane group. When the curable compound having a thiirane group and the curable compound having an epoxy group are used in combination as the thermosetting compound, the “thermosetting compound 100% by weight” means the curable compound having a thiirane group and an epoxy. A total of 100% by weight with the curable compound having a group is shown.

  From the viewpoint of curing more rapidly at a low temperature, the curable compound having a thiirane group is represented by the following formula (1-1), (2-1), (3), (7) or (8). An episulfide compound having a structure is preferable, and an episulfide compound having a structure represented by the following formula (1-1), (2-1) or (3) is more preferable.

  In the following formula (1-1), the bonding sites of the six groups bonded to the benzene ring are not particularly limited. In the following formula (2-1), the bonding sites of the eight groups bonded to the naphthalene ring are not particularly limited.

  In said formula (1-1), R1 and R2 represent a C1-C5 alkylene group, respectively. Of the four groups R3, R4, R5 and R6, 2 to 4 groups represent hydrogen. The group which is not hydrogen among R3, R4, R5 and R6 represents a group represented by the following formula (4). All four groups of R3, R4, R5 and R6 may be hydrogen. One or two of the four groups of R3, R4, R5 and R6 is a group represented by the following formula (4), and among the four groups of R3, R4, R5 and R6 The group that is not a group represented by the following formula (4) may be hydrogen.

  In said formula (4), R7 represents a C1-C5 alkylene group.

  In said formula (2-1), R51 and R52 represent a C1-C5 alkylene group, respectively. Of the 6 groups of R53, R54, R55, R56, R57 and R58, 4 to 6 groups represent hydrogen. The group which is not hydrogen among R53, R54, R55, R56, R57 and R58 represents a group represented by the following formula (5). All of the six groups of R53, R54, R55, R56, R57 and R58 may be hydrogen. One or two of the six groups of R53, R54, R55, R56, R57 and R58 are groups represented by the following formula (5), and R53, R54, R55, R56, R57 and R58. Of these, a group that is not a group represented by the following formula (5) may be hydrogen.

  In said formula (5), R59 represents a C1-C5 alkylene group.

  In said formula (3), R101 and R102 represent a C1-C5 alkylene group, respectively. Six to eight groups out of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 represent hydrogen. The group which is not hydrogen among R103, R104, R105, R106, R107, R108, R109 and R110 represents a group represented by the following formula (6). All of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 may be hydrogen. One or two of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 are groups represented by the following formula (6), and R103, R104, R105, R106 , R107, R108, R109 and R110, which is not a group represented by the following formula (6), may be hydrogen.

  In said formula (6), R111 represents a C1-C5 alkylene group.

  In said formula (7), R1 and R2 represent a C1-C5 alkylene group, respectively.

  In said formula (8), R3 and R4 represent a C1-C5 alkylene group, respectively.

  The curable compound having an epoxy group is not particularly limited. A conventionally well-known epoxy compound can be used as a curable compound which has an epoxy group. As for the said curable compound which has an epoxy group, only 1 type may be used and 2 or more types may be used together.

  Examples of the curable compound having an epoxy group include bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol aralkyl type epoxy resin, Examples thereof include naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, epoxy resins having an adamantane skeleton, epoxy resins having a tricyclodecane skeleton, and epoxy resins having a triazine nucleus in the skeleton.

  Furthermore, as the curable compound having the epoxy group, for example, an epoxy obtained by converting a thiirane group in the formula (1-1), (2-1), (3), (7) or (8) into an epoxy group. Compounds can be used.

  Furthermore, in the curable composition according to the present invention, as the curable compound having an epoxy group, an epoxy compound monomer having a structure represented by the following formula (21) and at least two of the epoxy compounds are bonded. A multimer, or a mixture of the monomer and the multimer.

  In said formula (21), R1 represents a C1-C5 alkylene group, R2 represents a C1-C5 alkylene group, R3 is a hydrogen atom, a C1-C5 alkyl group, or following formula ( 22), R4 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a structure represented by the following formula (23).

  In said formula (22), R5 represents a C1-C5 alkylene group.

  In said formula (23), R6 represents a C1-C5 alkylene group.

  The epoxy compound having the structure represented by the above formula (21) has an unsaturated double bond and at least two epoxy groups. By using the epoxy compound having the structure represented by the above formula (21), the curable composition can be rapidly cured at a low temperature.

  The curable composition according to the present invention includes a monomer of a compound having a structure represented by the following formula (31) as the curable compound having the thiirane group or the curable compound having the epoxy group, It may contain a multimer in which at least two are combined, or a mixture of the monomer and the multimer.

  In the above formula (31), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (32), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. X 1 represents an oxygen atom or a sulfur atom, and X 2 represents an oxygen atom or a sulfur atom.

  In said formula (32), R4 represents a C1-C5 alkylene group, X3 represents an oxygen atom or a sulfur atom.

  The curable composition concerning this invention may contain the epoxy compound which has a heterocyclic ring containing a nitrogen atom as a curable compound which has the said epoxy group. The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably an epoxy compound represented by the following formula (41) or an epoxy compound represented by the following formula (42). By using such a compound, the curing rate of the curable composition can be further increased, and the heat resistance of the cured product can be further enhanced.

  In said formula (41), R1-R3 represents a C1-C5 alkylene group, respectively, Z represents an epoxy group or a hydroxymethyl group. R1 to R3 may be the same or different.

  In the above formula (42), R1 to R3 each represent an alkylene group having 1 to 5 carbon atoms, p, q and r each represents an integer of 1 to 5, and R4 to R6 each represent an alkylene having 1 to 5 carbon atoms. Represents a group. R1 to R3 may be the same or different. p, q and r may be the same or different. R4-6 may be the same or different.

  The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably triglycidyl isocyanurate or trishydroxyethyl isocyanurate triglycidyl ether. By using these compounds, the curing rate of the curable composition can be further increased.

  It is preferable that the curable composition which concerns on this invention contains the epoxy compound which has an aromatic ring as a curable compound which has the said epoxy group. By using an epoxy compound having an aromatic ring, the curing rate of the curable composition can be further increased and the curable composition can be easily applied. From the viewpoint of further improving the applicability of the curable composition, the aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring. Examples of the epoxy compound having an aromatic ring include resorcinol diglycidyl ether or 1,6-naphthalenediglycidyl ether. Of these, resorcinol diglycidyl ether is particularly preferable. By using resorcinol diglycidyl ether, the curing rate of the curable composition can be increased and the curable composition can be easily applied.

[Phenolic compound]
The phenolic compound has a phenolic hydroxyl group in which a hydroxyl group is bonded to a benzene ring. Examples of the phenolic compound include polyphenol, triol, hydroquinone, and tocopherol (vitamin E). As for the said phenolic compound, only 1 type may be used and 2 or more types may be used together.

  The phenolic compound preferably has a primary hydroxyl group having a resonance structure and high acidity. The phenolic compound preferably has many functional groups to the extent that steric hindrance does not occur. Since the acidity is high, the phenolic compound preferably has a structure in which a primary hydroxyl group is directly bonded to the ortho or para position of the benzene ring.

  From the viewpoint of further increasing the curing rate and further enhancing the storage stability, the molecular weight of the phenolic compound is preferably less than 10,000, and preferably 1500 or less. In the present specification, the molecular weight means a molecular weight that can be calculated from the structural formula when the phenolic compound is not a polymer and when the structural formula of the phenolic compound can be specified. Moreover, when the said phenolic compound is a polymer, a weight average molecular weight is meant.

  From the viewpoint of further increasing the curing rate and further enhancing the storage stability, the content of the phenolic compound is within the range of 0.001 to 20% by weight in 100% by weight of the curable composition. Is preferred. In 100% by weight of the curable composition, a more preferable lower limit of the content of the phenolic compound is 0.01% by weight, a still more preferable lower limit is 0.1% by weight, a more preferable upper limit is 10% by weight, and a still more preferable upper limit is 5%. % By weight. From the viewpoint of further increasing the curing rate and further enhancing the storage stability, the content of the phenolic compound is in the range of 0.1 to 5% by weight in 100% by weight of the curable composition. Is more preferable.

  Further, from the viewpoint of further increasing the curing rate and further enhancing the storage stability, when the phenolic compound is hydroquinone, the content of hydroquinone is 0.1% in 100% by weight of the curable composition. It is preferably in the range of 1 to 5% by weight. Furthermore, from the viewpoint of further increasing the curing rate and further enhancing the storage stability, when the phenolic compound is hydroquinone, the content of hydroquinone is 0.1% in 100% by weight of the curable composition. When the phenolic compound is a component other than hydroquinone within the range of 1 to 5 wt%, the content of components other than hydroquinone is 0.001 to 20 wt% in 100 wt% of the curable composition. % Is preferable.

[Thermosetting agent]
The thermosetting agent contained in the curable composition according to the present invention is not particularly limited. The thermosetting agent cures the thermosetting compound. A conventionally known thermosetting agent can be used as the thermosetting agent. As for this thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents, and acid anhydrides. Especially, since a curable composition can be hardened more rapidly at low temperature, an imidazole hardening | curing agent, a polythiol hardening | curing agent, or an amine hardening | curing agent is preferable. Moreover, since a storage stability can be improved when the said thermosetting compound and the said thermosetting agent are mixed, a latent hardening agent is preferable. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. As for these thermosetting agents, only 1 type may be used and 2 or more types may be used together. In addition, the said thermosetting agent may be coat | covered with polymeric substances, such as a polyurethane resin or a polyester resin.

  The imidazole curing agent is not particularly limited, but 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.

  The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

  Although it does not specifically limit as said amine hardening | curing agent, Hexamethylene diamine, octamethylene diamine, decamethylene diamine, 3,9-bis (3-aminopropyl) 2,4,8,10-tetraspiro [5.5] undecane , Bis (4-aminocyclohexyl) methane, metaphenylenediamine, diaminodiphenylsulfone and the like.

  Among the thermosetting agents, polythiol compounds or acid anhydrides are preferably used. Since the curing rate of the curable composition can be further increased, a polythiol compound is more preferably used.

  Among the polythiol compounds, pentaerythritol tetrakis-3-mercaptopropionate is more preferable. By using this polythiol compound, the curing rate of the curable composition can be further increased.

  The glass transition temperature of the thermosetting agent is preferably 60 ° C. or lower, more preferably 50 ° C. or lower. When the glass transition temperature of the thermosetting agent is not more than the above upper limit, the cured product and the polyimide base material are likely to adhere to each other, and the adhesive strength of the cured product is further increased. The glass transition temperature of the thermosetting agent is preferably 25 ° C. or higher, more preferably 30 ° C. or higher.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably in the range of 0.01 to 200 parts by weight and more preferably in the range of 1 to 40 parts by weight with respect to 100 parts by weight of the thermosetting compound. The more preferable lower limit of the content of the thermosetting agent is 30 parts by weight, the more preferable lower limit is 45 parts by weight, the more preferable upper limit is 100 parts by weight, and the still more preferable upper limit is 75 parts by weight with respect to 100 parts by weight of the thermosetting compound. Part. When content of a thermosetting agent satisfy | fills the said minimum, it is easy to fully harden a curable composition. When content of a thermosetting agent satisfy | fills the said upper limit, the excess thermosetting agent which did not participate in hardening after hardening will not remain easily, and the heat resistance of hardened | cured material can be improved further.

  In addition, when the said thermosetting agent is an imidazole hardening agent or a phenol hardening agent, content of an imidazole hardening agent or a phenol hardening agent exists in the range of 1-15 weight part with respect to 100 weight part of said curable compounds. It is preferable. When the thermosetting agent is an amine curing agent, a polythiol curing agent or an acid anhydride, the content of the amine curing agent, polythiol curing agent or acid anhydride is 15 to 100 parts by weight of the curable compound. It is preferably within the range of 40 parts by weight.

[Other ingredients]
The curable composition according to the present invention preferably further contains a curing accelerator. By using a curing accelerator, the curing rate of the curable composition can be further increased. As for a hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the curing accelerator include imidazole curing accelerators and amine curing accelerators. Of these, imidazole curing accelerators are preferred. In addition, an imidazole hardening accelerator or an amine hardening accelerator can be used also as an imidazole hardening agent or an amine hardening agent.

  Examples of the imidazole curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine and 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid addition Thing etc. are mentioned.

  A preferable lower limit of the content of the curing accelerator is 0.5 parts by weight, a more preferable lower limit is 1 part by weight, a preferable upper limit is 6 parts by weight, and a more preferable upper limit is 4 parts by weight with respect to 100 parts by weight of the thermosetting compound. Part. When the content of the curing accelerator satisfies the above lower limit, it is easy to sufficiently cure the curable composition. When content of a hardening accelerator satisfy | fills the said upper limit, it will become difficult to remain | survive the excessive hardening accelerator which did not participate in hardening after hardening.

  The curable composition concerning this invention may further contain the photocurable compound so that it may harden | cure also by light irradiation. Moreover, when a photocurable compound is contained, the curable composition concerning this invention may further contain the photoinitiator. However, when using the curable composition concerning this invention, you may add a photoinitiator to this curable composition. By using the photocurable compound and the photopolymerization initiator, the curable composition can be cured by light irradiation. Furthermore, the curable composition can be semi-cured to reduce the fluidity of the curable composition.

  The said photocurable compound is not specifically limited. As the photocurable compound, a (meth) acrylic resin or a cyclic ether group-containing resin is preferably used, and a (meth) acrylic resin is more preferably used. The (meth) acrylic resin indicates a methacrylic resin and an acrylic resin. The (meth) acrylic resin has a (meth) acryloyl group. The (meth) acryloyl group represents a methacryloyl group and an acryloyl group.

  In the composition containing the thermosetting compound and the (meth) acrylic resin, when the epoxy group or thiirane group of the thermosetting compound is ring-opened to generate a radical, a (meth) acrylic is produced by the action of the radical. Resin polymerization is likely to proceed. However, when the phenolic compound and the storage stabilizer are combined with the thermosetting compound, the epoxy group or thiirane group is difficult to open during storage of the curable composition. As a result, polymerization of the (meth) acrylic resin is difficult to proceed during storage of the curable composition.

  As the (meth) acrylic resin, an ester compound obtained by reacting (meth) acrylic acid and a compound having a hydroxyl group, an epoxy (meth) acrylate obtained by reacting (meth) acrylic acid and an epoxy compound, or Urethane (meth) acrylate obtained by reacting a (meth) acrylic acid derivative having a hydroxyl group with isocyanate is preferably used.

  The ester compound obtained by making the said (meth) acrylic acid and the compound which has a hydroxyl group react is not specifically limited. As the ester compound, any of a monofunctional ester compound, a bifunctional ester compound, and a trifunctional or higher functional ester compound can be used.

  It is preferable that the said photocurable compound contains the light and thermosetting compound (henceforth a partial (meth) acrylated epoxy resin) which has an epoxy group and a (meth) acryloyl group.

  The partially (meth) acrylated epoxy resin can be obtained, for example, by reacting an epoxy resin and (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. It is preferable that 20% or more of the epoxy groups are converted to (meth) acryloyl groups (conversion rate) and partially (meth) acrylated. More preferably, 50% of the epoxy groups are converted to (meth) acryloyl groups.

  Examples of the epoxy (meth) acrylate include bisphenol type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, carboxylic acid anhydride-modified epoxy (meth) acrylate, and phenol novolac type epoxy (meth) acrylate. .

  When a photocurable compound other than the photocurable compounds described above is included, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

  Specific examples of the crosslinkable compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, glycerol methacrylate acrylate, pentaerythritol tri (meth) acrylate, tri Examples include methylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, polyester (meth) acrylate, and urethane (meth) acrylate.

  Specific examples of the non-crosslinkable compound include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl Examples include (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, and tetradecyl (meth) acrylate.

  From the viewpoint of efficiently photocuring the curable composition, the photocurable compound (when the photocurable compound is a (meth) acrylic resin) with respect to 100 parts by weight of the thermosetting compound. The preferred lower limit of the content of (meth) acrylic resin) is 0.1 parts by weight, the more preferred lower limit is 1 part by weight, the still more preferred lower limit is 10 parts by weight, the particularly preferred lower limit is 50 parts by weight, the preferred upper limit is 10,000 parts by weight, A more preferred upper limit is 1000 parts by weight, and a still more preferred upper limit is 500 parts by weight.

  The photopolymerization initiator is not particularly limited. As for the said photoinitiator, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the photopolymerization initiator include acetophenone photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone, ketal photopolymerization initiator, halogenated ketone, acyl phosphinoxide, and acyl phosphonate.

  Specific examples of the acetophenone photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methoxy Examples include acetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-cyclohexylacetophenone. Specific examples of the ketal photopolymerization initiator include benzyl dimethyl ketal.

  The content of the photopolymerization initiator is not particularly limited. The preferred lower limit of the content of the photopolymerization initiator is 0.1 parts by weight, more preferred lower limit is 0.2 parts by weight, and still more preferred lower limit is 2 parts by weight, with respect to 100 parts by weight of the photocurable compound. Is 10 parts by weight, and a more preferred upper limit is 5 parts by weight. When the content of the photopolymerization initiator satisfies the above lower limit, it is easy to sufficiently obtain the effect of adding the photopolymerization initiator. When content of a photoinitiator satisfy | fills the said upper limit, the adhesive force of the hardened | cured material of a curable composition will become high enough.

  The curable composition according to the present invention preferably further contains a filler. By using the filler, latent heat expansion of the cured product of the curable composition can be suppressed. As for a filler, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the filler include silica, aluminum nitride, and alumina. The filler is preferably filler particles. The average particle size of the filler particles is preferably in the range of 0.1 to 1.0 μm. When the average particle diameter of the filler particles is within the above range, latent heat expansion of the cured product of the curable composition can be further suppressed. “Average particle diameter” refers to a volume average diameter measured by a dynamic laser scattering method.

  The filler content is preferably in the range of 50 to 900 parts by weight with respect to 100 parts by weight of the thermosetting compound. When the filler content is within the above range, the latent thermal expansion of the cured product of the curable composition can be further suppressed.

  The curable composition according to the present invention may contain a solvent. By using the solvent, the viscosity of the curable composition can be easily adjusted. Furthermore, for example, when the thermosetting compound is solid, the dispersibility of the thermosetting compound can be improved by adding a solvent to the solid thermosetting compound and dissolving it.

  Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  The curable composition according to the present invention preferably further contains a storage stabilizer. The curable composition according to the present invention preferably contains at least one selected from the group consisting of phosphate ester, phosphite ester and borate ester as the storage stabilizer, and phosphate ester and phosphorous acid. It is more preferable to include at least one of the esters, and it is even more preferable to include a phosphite. By using these storage stabilizers, particularly by using phosphites, the storage stability of the curable compound having a thiirane group can be further enhanced. As for the said storage stabilizer, only 1 type may be used and 2 or more types may be used together.

Examples of the phosphate ester include diethyl benzyl phosphate, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, tris (butoxyethyl) phosphate, tris (2-ethylhexyl) phosphate, (RO) ₃ P═O [R = lauryl group Cetyl group, stearyl group or oleyl group], tris (2-chloroethyl) phosphate, tris (2-dichloropropyl) phosphate, triphenyl phosphate, butyl pyrophosphate, tricresyl phosphate, trixylenyl phosphate, octyl diphenyl phosphate, Cresyl diphenyl phosphate, xylenyl diphosphate, monobutyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, monoisodecyl phosphate Feto, ammonium ethyl acid phosphate, and 2-ethylhexyl acid phosphate salt. Of these, diethylbenzyl phosphate is preferably used.

  Examples of the phosphite include trimethyl phosphite, triethyl phosphite, tri n-butyl phosphite, tris (2-ethylhexyl) phosphite, triisooctyl phosphite, tridecyl phosphite, triisodecyl phosphite, tris (Tridecyl) phosphite, trioleyl phosphite, tristearyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, phenyl diisooctyl phosphite Phyto, phenyl diisodecyl phosphite, diphenyl mono (2-ethylhexyl) phosphite, diphenyl isooctyl phosphite, diphenyl monodecyl phosphite, diphenyl monoisodecyl phosphite, di Phenyl mono (tridecyl) phosphite, bis (nonylphenyl) dinonylphenyl phosphite, tetraphenyldipropylene glycol diphosphite, poly (dipropylene glycol) phenyl phosphite, diisodecylpentaerythritol diphosphite, bis (tridecyl) pentaerythritol Diphosphite, distearyl pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite, tetra (tridecyl) -4,4′-isopropylidene diphenylphosphite , Trilauryl trithiophosphite, dimethyl hydrogen phosphite, dibutyl hydrogen phosphite, di (2-e Ruhexyl) hydrodiene phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, diphenyl hydrogen phosphite, diphenyl mono (2-ethylhexyl) phosphite, diphenyl monodecyl phosphite, and diphenyl mono (tridecyl) phos Fight etc. are mentioned. Among them, diphenyl mono (2-ethylhexyl) phosphite, diphenyl monodecyl phosphite or diphenyl mono (tridecyl) phosphite is preferable, diphenyl monodecyl phosphite or diphenyl mono (tridecyl) phosphite is more preferable, and diphenyl mono (tridecyl). More preferred are phosphites.

  In 100% by weight of the curable composition, the content of the storage stabilizer is preferably in the range of 0.001 to 5% by weight, preferably in the range of 0.001 to 1% by weight, More preferably, it is within the range of 0.001 to 0.1% by weight. In 100% by weight of the curable composition, the more preferable lower limit of the content of the storage stabilizer is 0.005% by weight, and the more preferable upper limit is 0.05% by weight. When the content of the storage stabilizer is within the above range, the storage stability of the curable composition can be further enhanced.

  The curable composition according to the present invention is at least one component selected from the group consisting of ascorbic acid, a derivative of ascorbic acid, a salt of ascorbic acid, isoascorbic acid, a derivative of isoascorbic acid, and a salt of isoascorbic acid May be included. By blending these components, the storage stability of the curable composition is increased.

  The curable composition concerning this invention may further contain the ion-trapping agent or the silane coupling agent as needed.

[Curable composition containing conductive particles]
When the curable composition according to the present invention further contains conductive particles, the curable composition can be used as an anisotropic conductive material. Since the curable composition according to the present invention includes a curable compound having a thiirane group, a thermosetting agent, and a phenolic compound, the curable composition including conductive particles is disposed between the electrodes, and the conductive particles are disposed. Appropriate indentations can be formed on the electrode when the is compressed. Therefore, the connection resistance between the electrodes can be lowered.

  For example, the conductive particles electrically connect the electrodes of the circuit board and the semiconductor chip. The conductive particles preferably have conductivity on at least the surface. Examples of the conductive particles include conductive particles whose surfaces are coated with a metal layer, such as organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, or metal particles that are substantially composed of only metal. It is done. The metal layer is not particularly limited. Examples of the metal layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a metal layer containing tin.

  From the viewpoint of further improving the conduction reliability between the electrodes, the conductive particles preferably include resin particles and a conductive layer disposed on the surface of the resin particles. The conductive particles may be conductive particles in which at least the outer surface layer of the conductive layer is a solder layer.

  Although the material which comprises the said solder layer is not specifically limited, Based on JISZ3001: solvent term, it is preferable that it is a meltable material whose liquidus is 450 degrees C or less. As a composition of the said solder layer, the metal composition containing zinc, gold | metal | money, lead, copper, tin, bismuth, indium etc. is mentioned, for example. Among them, a tin-indium system (117 ° C. eutectic) or a tin-bismuth system (139 ° C. eutectic) which is low-melting and lead-free is preferable. That is, the solder layer preferably does not contain lead, and is preferably a solder layer containing tin and indium or a solder layer containing tin and bismuth.

  The thickness of the solder layer is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 20 nm or more, preferably 40000 nm or less, more preferably 30000 nm or less, still more preferably 20000 nm or less, and particularly preferably 10,000 nm or less. When the thickness of the solder layer is not less than the above lower limit, the conductivity can be sufficiently increased. When the thickness of the conductive layer is not more than the above upper limit, the difference in the coefficient of thermal expansion between the resin particles and the solder layer becomes small, and the solder layer is hardly peeled off.

  The content of the conductive particles is not particularly limited. In 100% by weight of the curable composition, the content of the conductive particles is preferably in the range of 0.1 to 20% by weight. In 100% by weight of the curable composition, the more preferable lower limit of the content of the conductive particles is 0.5% by weight, the more preferable upper limit is 10% by weight, and the still more preferable upper limit is 5% by weight. When the content of the conductive particles is within the above range, the conductive particles can be easily arranged between the upper and lower electrodes to be connected. Furthermore, it becomes difficult to electrically connect adjacent electrodes that should not be connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be prevented.

  When the curable composition is in a paste form, the viscosity (25 ° C.) of the curable composition is preferably in the range of 20000 to 100000 mPa · s. If the viscosity is too low, the conductive particles may settle. If the viscosity is too high, the conductive particles may not be sufficiently dispersed.

(Use of curable composition)
The curable composition concerning this invention can be used for adhere | attaching various connection object members.

  When the curable composition according to the present invention is an anisotropic conductive material containing conductive particles, the anisotropic conductive material can be used as an anisotropic conductive paste or an anisotropic conductive film. When the anisotropic conductive material is an anisotropic conductive film, a film not containing conductive particles may be laminated on the anisotropic conductive film containing the conductive particles.

  The anisotropic conductive material is suitably used for obtaining a connection structure in which the first and second connection target members are electrically connected.

  In FIG. 1, an example of the connection structure using the curable composition which concerns on one Embodiment of this invention is typically shown with sectional drawing.

  A connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a connection part 3 connecting the first and second connection target members 2 and 4. Prepare. The connection part 3 is formed by hardening the curable composition containing the electroconductive particle 5, ie, an anisotropic conductive material.

  A plurality of electrodes 2 b are provided on the upper surface 2 a of the first connection target member 2. A plurality of electrodes 4 b are provided on the lower surface 4 a of the second connection target member 4. The electrode 2b and the electrode 4b are electrically connected by one or a plurality of conductive particles 5. Therefore, the first and second connection target members 2 and 4 are electrically connected by the conductive particles 5.

  Specifically, as the connection structure, an electronic component chip such as a semiconductor chip, a capacitor chip or a diode chip is mounted on a circuit board, and the electrode of the electronic component chip is connected to an electrode on the circuit board. Examples include electrically connected structures. As a circuit board, various printed circuit boards, such as various printed circuit boards, such as a flexible printed circuit board, a glass substrate, or a board | substrate with which metal foil was laminated | stacked are mentioned. The first and second connection target members are preferably electronic components or circuit boards. The curable composition is preferably used for connecting an electronic component or a circuit board. The curable composition is in a paste form, and is preferably a curable composition applied on the connection target member in a paste state.

  The manufacturing method of the connection structure is not particularly limited. As an example of a manufacturing method of a connection structure, the anisotropic conductive material is disposed between a first connection target member such as an electronic component or a circuit board and a second connection target member such as an electronic component or a circuit board. And after obtaining a laminated body, the method etc. which heat and pressurize this laminated body are mentioned.

  In addition, the said curable composition does not need to contain electroconductive particle. In this case, the curable composition is used to bond and connect the first and second connection target members without electrically connecting the first and second connection target members.

  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) Preparation of mixture A corresponding to the thermosetting compound In a 2 L container equipped with a stirrer, a cooler and a thermometer, 250 mL of ethanol, 250 mL of pure water, and 20 g of potassium thiocyanate were added, and thiocyanic acid was added. Potassium was dissolved to prepare a first solution. Thereafter, the temperature in the container was kept in the range of 20 to 25 ° C. Next, 160 g of resorcinol diglycidyl ether was dropped into the first solution at a rate of 5 mL / min while stirring the first solution in the container maintained at 20 to 25 ° C. After dropping, the mixture was further stirred for 30 minutes to obtain an epoxy compound-containing solution.

  Next, a second solution in which 20 g of potassium thiocyanate was dissolved in a solution containing 100 mL of pure water and 100 mL of ethanol was prepared. The obtained second solution was added to the obtained epoxy compound-containing solution at a rate of 5 mL / min, and then stirred for 30 minutes. After stirring, a second solution prepared by dissolving 20 g of potassium thiocyanate in a solution containing 100 mL of pure water and 100 mL of ethanol is further prepared, and the second solution is further added to the container at a rate of 5 mL / min. And stirred for 30 minutes. Thereafter, the temperature in the container was cooled to 10 ° C., and stirred for 2 hours to be reacted.

  Next, 100 mL of saturated saline was added to the container and stirred for 10 minutes. After stirring, 300 mL of toluene was further added to the container and stirred for 10 minutes. Thereafter, the solution in the container was transferred to a separating funnel and allowed to stand for 2 hours to separate the solution. The lower solution in the separatory funnel was discharged, and the supernatant was taken out. 100 mL of toluene was added to the removed supernatant, stirred, and allowed to stand for 2 hours. Further, 100 mL of toluene was further added, stirred and allowed to stand for 2 hours.

  Next, 50 g of magnesium sulfate was added to the supernatant liquid to which toluene was added and stirred for 5 minutes. After stirring, magnesium sulfate was removed with a filter paper to separate the solution. The remaining solvent was removed by drying the separated solution under reduced pressure at 80 ° C. using a vacuum dryer. In this way, a mixture A of a curable compound having a thiirane group and a curable compound having an epoxy group was obtained.

¹ H-NMR of the obtained mixture A was measured using chloroform as a solvent. As a result, the signal in the region of 6.5 to 7.5 ppm indicating the presence of the epoxy group decreased, and the signal appeared in the region of 2.0 to 3.0 ppm indicating the presence of the thiirane group. This confirmed that some epoxy groups of resorcinol diglycidyl ether were converted to thiirane groups. Moreover, from the integrated value of the measurement result of ¹ H-NMR, the mixture A contains 70% by weight of resorcinol diglycidyl ether and 30% by weight of an episulfide compound having a structure represented by the following formula (1B). It was confirmed.

(2) Preparation of curable composition In 33 parts by weight of the mixture A corresponding to the thermosetting compound, 0.58 parts by weight of α-methylbenzylphenol as a phenolic compound and pentaerythritol tetrakis- as a thermosetting agent 20 parts by weight of 3-mercaptopropionate, 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator, 20 parts by weight of silica having an average particle diameter of 0.25 μm and an average particle diameter of 0.5 μm as fillers 20 parts by weight of alumina and 2 parts by weight of conductive particles having an average particle diameter of 3 μm were added and stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a curable composition as an anisotropic conductive paste. Obtained. The conductive particles used are conductive particles having a metal layer in which a nickel plating layer is formed on the surface of divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer. .

(Example 2)
A curable composition was prepared in the same manner as in Example 1 except that 0.58 parts by weight of 2,6-ditertiarybutylphenol was used as the phenolic compound instead of 0.58 parts by weight of α-methylbenzylphenol. Obtained.

(Example 3)
The curable composition was the same as in Example 1 except that 0.58 parts by weight of 2,2′-methylenebisbutylphenol was used as the phenolic compound instead of 0.58 parts by weight of α-methylbenzylphenol. Got.

Example 4
A curable composition was prepared in the same manner as in Example 1 except that 0.58 parts by weight of 2,2′-thiobisphenol was used as the phenolic compound instead of 0.58 parts by weight of α-methylbenzylphenol. Obtained.

(Example 5)
A curable composition was obtained in the same manner as in Example 1 except that 0.01 part by weight of diethyl hydrogen phosphite as a phosphate ester was further added before stirring with a planetary stirrer.

(Example 6)
Before stirring using a planetary stirrer, 5 parts by weight of an epoxy acrylate ((meth) acrylic resin, “EBECRYL 3702” manufactured by Daicel-Cytec, Inc.), which is a photocurable compound, and an acylphosphine oxide system, which is a photopolymerization initiator A curable composition was obtained in the same manner as in Example 1 except that 0.1 part by weight of a compound ("DAROCUR TPO" manufactured by Ciba Japan) was further added.

(Example 7)
Before stirring with a planetary stirrer, 5 parts by weight of urethane acrylate ((meth) acrylic resin, “EBECRYL8804” manufactured by Daicel-Cytec, Inc.), which is a photocurable compound, and an acylphosphine oxide system, which is a photopolymerization initiator A curable composition was obtained in the same manner as in Example 1 except that 0.1 part by weight of a compound ("DAROCUR TPO" manufactured by Ciba Japan) was further added.

(Comparative Example 1)
Photopolymerization started with 33 parts by weight of bisphenol A phenoxy resin (“PKHC” manufactured by Sakai Kogyo Co., Ltd.) and 5 parts by weight of epoxy acrylate ((meth) acrylic resin, “EBECRYL 3702” manufactured by Daicel-Cytec). 0.1 parts by weight of an acylphosphine oxide compound (“DAROCUR TPO” manufactured by Ciba Japan), 0.58 parts by weight of α-methylbenzylphenol which is a phenolic compound, and pentaerythritol which is a thermosetting agent 20 parts by weight of tetrakis-3-mercaptopropionate, 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator, 20 parts by weight of silica having an average particle diameter of 0.25 μm and an average particle diameter of 0 as fillers 20 parts by weight of 5 μm alumina and 2 parts by weight of conductive particles used in Example 1 It was added and in which, by stirring for 5 minutes at 2000rpm using a planetary stirrer to obtain a curable composition is an anisotropic conductive paste.

(Comparative Example 2)
In the same manner as in Comparative Example 1, except that the bisphenol A phenoxy resin (“PKHC” manufactured by Sakai Kogyo Co., Ltd.) was changed to a phenoxy resin (“4250” manufactured by Mitsubishi Chemical Corporation), which is a mixture of bisphenol A and bisphenol F, A curable composition that was an anisotropic conductive paste was prepared.

(Evaluation of Examples and Comparative Examples)
(Adhesive strength evaluation)
The obtained curable composition was applied to a glass plate having a size of 4 cm × 2 cm so as to have a size of 2 cm × 2 cm so that the thickness after drying was 20 μm. Next, after irradiating the curable composition with 420 nm ultraviolet light so that the light irradiation intensity becomes 60 mW / cm ² , the glass plate and the polyimide were used with a constant heater type crimping machine (Ohashi Seisakusho “BD-03SDSS”). A film (manufactured by Toray Industries, Inc.) was bonded to the film under the conditions of a pressure bonding temperature of 150 ° C. and a pressure of 294.2 N / cm ² via a light irradiation product of a curable composition, thereby obtaining a sample for measuring an adhesive force.

  Using a static material tester (“EZ-Graph” manufactured by Shimadzu Corporation), a 90 ° peel test was performed on the obtained adhesive force measurement sample at a pulling speed of 50 mm / min. The maximum value of the obtained 90-degree peel strength was taken as a measured value of adhesive strength.

(Evaluation of curing time)
A state in which heat generation of 90% of the total curing heat generation amount was finished was measured by DSC (Differential Scanning Thermal Analysis) (measurement condition; sample amount 2 mg, room temperature to 150 ° C., 10 ° C./minute temperature increase). This was taken as the curing time.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 3 ... Connection part 4 ... 2nd connection object member 4a ... Lower surface 4b ... Electrode 5 ... Conductive particle

Claims (7)

  A curable composition comprising a curable compound having a thiirane group, a thermosetting agent, and a phenolic compound.   The curable composition according to claim 1, further comprising a curable compound having an epoxy group different from the curable compound having a thiirane group.   The curable composition according to claim 1 or 2, further comprising a compound having a (meth) acryloyl group and a photopolymerization initiator.   The curable composition according to any one of claims 1 to 3, wherein a content of the phenolic compound is 0.1 to 20% by weight in 100% by weight of the curable composition. Further comprising conductive particles;
The curable composition according to any one of claims 1 to 4, which is an anisotropic conductive material. A first connection target member, a second connection target member, and a connection part connecting the first and second connection target members;
The connection structure in which the said connection part is formed with the curable composition of any one of Claims 1-5. The curable composition is an anisotropic conductive material containing conductive particles,
The connection structure according to claim 6, wherein the first and second connection target members are electrically connected by the conductive particles.

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