JP2001302881A - Stabilized cationic polymerizable composition and adhesive film and conductive circuit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cationic polymerizable composition capable of being prepared in one-part type and excellent in stability. SOLUTION: This cationic polymerizable composition is obtained by including a cationic polymerizable monomer, a cationic polymerization initiator and a quinoline compound represented by the formula (wherein, Rs are mutually independent and are each H or an alkyl) as a stabilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilized cationically polymerizable composition, an adhesive film using the same, and a conductor circuit.

[0002]

2. Description of the Related Art An epoxy composition containing an organic compound having at least one epoxy group (hereinafter also referred to as "epoxy resin", "epoxide" or "epoxy monomer") (hereinafter referred to as "epoxy resin composition"). Is also called.)
Widely used in adhesives. Such an organic compound having an epoxy group is generally cured by adding a curing agent or a solidifying agent. The curing agent generally starts working immediately, even at room temperature, or starts working within a short time. In such cases, one-part epoxy compositions have inherent problems with storage stability. Therefore,
Many epoxy compositions are two-part. The epoxide and curing agent are stored separately and are only mixed immediately before use.

[0003] In many applications, even if an epoxide and a curing agent are mixed to prepare a one-part form, the composition is stable before use.
It is desired that it can be cured by heating at the time of use.
If the one-part type epoxy composition is stored stably for a period of time before use, prepare a large batch in advance,
This is because they can be used little by little as needed. That is, if the shelf life of the epoxy composition before curing can be extended, it can be stored as a one-part composition. In general, it has been found that as the shelf life of the epoxy composition increases, the cure rate decreases accordingly. Further, to complete the curing reaction by consuming all the epoxy groups, it is necessary to raise the curing temperature. However, in some applications where the adherend does not have heat resistance, such as bonding general purpose plastic materials, it is desired that the epoxy composition cure at lower temperatures. In this case, it is necessary to use a curing agent having a high activity at a low temperature, but it is necessary to avoid sacrificing the shelf life before curing as described above. The realization of high activity at low temperatures and the practical long shelf life are contradictory and generally difficult to achieve.

[0004] When polymerizing a cationically polymerizable monomer such as an epoxide, in order to increase the polymerizability at a lower temperature and to have a practical pot life, an ultraviolet ray activity that exhibits polymerization initiation activity by irradiation with ultraviolet rays. A cationic polymerization initiator, typically, a bis-arene-type metal complex salt is used. Even when such a polymerization initiator is mixed with the epoxy composition, the cationic polymerization of the epoxy monomer is not started before the irradiation of ultraviolet rays, so that it is expected that the epoxy composition can realize high storage stability.

[0005] Adhesion between the epoxy composition and the adherend may involve thermocompression bonding, if necessary. For example, an epoxy composition is applied to an anisotropic conductive adhesive film, and this film is used as a flexible printed wiring board (FPC: Flex).
ible Printed Circuit), TAB (Tape Automated Bon)
ding) carrier tape, printed wiring board (PCB: Pri)
This is used to form a conductive circuit by electrically connecting an electronic circuit board such as an nted circuit board or a glass circuit board. Once the UV-activated cationic polymerization initiator is activated by UV irradiation,
The curing of the epoxy composition is started quickly at a relatively low temperature. Thereafter, thermocompression bonding is usually performed at a relatively low temperature of around 100 ° C. to flow the composition to form a conductor circuit, and to complete the reaction in a short time of ten and several seconds.

However, in practice, it may be necessary to perform thermocompression bonding after a relatively long time has passed since the curing of the epoxy composition with ultraviolet light started. In such a case, a stabilizer is further added to the epoxy composition to inhibit or delay the cationic polymerization of the epoxy monomer. Needless to say, these stabilizers are also effective in thermal cationic polymerization without ultraviolet irradiation.

For example, Japanese Patent Application Laid-Open No. 10-152600 discloses a resin composition for encapsulating a semiconductor in which a crown ether is added to an epoxy monomer as a stabilizer. Although this publication describes that crown ether stabilizers suppress the deterioration of semiconductors during storage at high temperatures, crown ethers are generally very hydrophilic due to their oxygen atoms, and are used for semiconductor encapsulation. This may promote an increase in the water absorption of the resin composition, and as a result, the resin composition for semiconductor encapsulation may have poor crack resistance.

Further, Japanese Patent Application Laid-Open Nos. Hei 4-227625, Hei 8-511570 and Hei 8-511572
And EP 0 613 241 disclose a stabilizer comprising a compound having a coordinating atom of a nitrogen atom. More specifically, JP-A-4-227625 discloses a stabilizer for a specific primary amine added to an epoxy resin composition. Tokuhyo Hei 8-51157
No. 0 discloses an aromatic amine stabilizer added to the conductive adhesive composition. Furthermore, EP 0 613 241 discloses a stabilizer comprising 8-hydroxyquinoline or an 8-position-substituted product thereof, which has an oxygen atom as a coordinating atom in addition to a nitrogen atom.

However, all stabilizers tend to significantly inhibit the low temperature cationic polymerization of epoxy monomers. Therefore, the thermocompression bonding requires a relatively high temperature and a long time. However, high-temperature and long-time thermocompression adversely affect productivity and electrical connection, respectively. Conversely, when thermocompression bonding is performed at a relatively low temperature and for a short time, the composition is not completely cured and the composition is unstable.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a stabilized cationically polymerizable composition which solves the above problems. Another object of the present invention is to provide an adhesive film and a conductive circuit using such a cationically polymerizable composition.

[0011]

According to the present invention, an object of the present invention is to provide a cationically polymerizable composition comprising (1) a cationically polymerizable monomer, a cationic polymerization initiator, and a stabilizer comprising quinolines. Wherein the quinolines have the following formula:

Embedded image (Wherein, R is, independently of each other, a hydrogen atom or an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, particularly Is an alkyl group. And (2) a thermoplastic material having an epoxy group in the molecule, a cationically polymerizable monomer, a cationically polymerizable initiator, and a stable material comprising a quinoline represented by the above general formula. An adhesive film comprising an agent and an optionally dispersed conductive material, and (3) two adherends having a conductor on the surface by the adhesive film of the present invention containing the dispersed conductive material While combining
The problem can be solved by a conductor circuit in which the conductive substances are brought into contact with each other between the conductors to electrically connect the conductors to each other.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in accordance with preferred embodiments with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to these embodiments.

FIG. 1 shows a pair of electronic circuit boards (12, 1).
8) A conductor circuit (20) in which the (adherend) is mechanically and electrically interconnected is shown. More specifically, an adhesive layer (16) is interposed between the electronic circuit boards in order to bond and fix the electronic circuit boards (12, 18) to each other. According to the present invention, the adhesive layer comprises a cationically polymerizable monomer, a cationic polymerization initiator, a stabilizer comprising a quinoline represented by the above general formula, and a conductive substance (24,
28) is formed from a cationically polymerizable composition basically comprising:

The matrix of the adhesive layer (16) is formed by polymerization from the cationic polymerizable monomer, and adheres and fixes the electronic circuit boards (12, 18) in the conductor circuit (20). The cationically polymerizable monomer is usually at least one epoxy resin and / or vinyl ether containing material. Such a monomer is polymerized in the presence of a cationic polymerization initiator to form a thermosetting resin having excellent adhesive performance and heat resistance.

The above-mentioned epoxy resin preferably includes an alicyclic epoxy resin, a bisphenol A type epoxy resin, a phenol novolak type epoxy resin and the like. The alicyclic epoxy resin is commercially available, for example, from Union Carbide Co. under the trade names "ERL-4221" and "ERL-4229", or from Daicel Chemical Industries, Ltd. under the trade name "Eporide GT401". Bisphenol A type epoxy resins are commercially available from Yuka Shell Epoxy Co., Ltd. under the trade names "Epicoat 828" and "YL980". Phenol novolak type epoxy resins are commercially available from Yuka Shell Epoxy Co., Ltd. under the trade names "Epicoat 152", "Epicoat 154" and "CT128". Vinyl ether-containing substances
From RSP-Cure
It is commercially available under the trade names “DVE-3” and “Rapi-Cure CHVE”.

The cationic polymerization initiator can be activated by heat, ultraviolet light, electron beam or other radiation to initiate a polymerization reaction of the cationically polymerizable monomer.
Preferred cationic polymerization initiators are cyclopentadienyl iron (II) (xylene) hexafluoroantimonate (CpFeXySbF ₆ ) or cyclopentadienyl iron (II) from the viewpoint that polymerization can be performed at a low temperature by ultraviolet irradiation.
(Cumene) bis-arene-type metal complex salts such as hexafluorophosphate (CpFeCmPF ₆ ). Cyclopentadienyl iron (II) (cumene) hexafluorophosphate is commercially available, for example, from Ciba Geigy Co., Ltd. under the trade name “Irgacure (trademark) 261”. From the viewpoint that polymerization can be performed by heat, bis-arene-type metal complex salts such as bismesityleneiron (II) bis {tris (trifluoromethylsulfonylmeside)} (MeFeMeMtd) are also included in the preferred cationic polymerization initiator. . Of these, cyclopentadienyl iron (II)
UV-activated cationic polymerization initiators such as (xylene) hexafluoroantimonate, even when mixed with a cationic polymerizable monomer,
Does not initiate cationic polymerization of epoxy monomers. Therefore, a cationically polymerizable composition containing a UV-activated cationic polymerization initiator as a polymerization initiator can have high storage stability at room temperature. The UV-activated cationic polymerization initiator is not limited to the above, and is disclosed in
Ultraviolet activatable described in -511572 discloses a cationic polymerization initiator, specifically, (eta ⁵ - cyclopentadienyl) (eta ⁶ - arene) iron complex is also desirable.

The curing rate of the cationically polymerizable composition can be appropriately adjusted by a stabilizer. In general, a stabilizer can prevent a polymerization initiation reaction of a cationically polymerizable monomer by capturing a cationic polymerization initiator with a coordinating atom, and can prolong the curing time (that is, the pot life) of the cationically polymerizable composition. In particular, according to the present invention, the stabilizer comprises quinolines generally represented by the above general formula. The pot life here means the time from ultraviolet irradiation to thermocompression bonding in the case of an ultraviolet irradiation type cationic polymerization initiator, and in the case of a thermal cationic polymerization initiator, the initiator and the cationic polymerizable monomer are mixed. It means the time from thermal compression to thermocompression bonding.

The quinolines represented by the above general formula have only one nitrogen atom as a coordinating atom, unlike 8-hydroxyquinoline described in the section of "prior art".
As a result, these quinolines immediately release the trapped cation polymerization initiator by heating at a relatively low temperature of 90 to 150 ° C., and start the polymerization of the cation polymerizable monomer within a short period of time. The polymerizable composition can be cured in a short time. In contrast, 8-hydroxyquinoline can release the cationic polymerization initiator only by heating at a high temperature of 200 to 250 ° C. due to its too high stabilizing effect.

According to the present invention, the cationically polymerizable composition can be cured at a relatively low temperature and for a short time by using the above quinolines as a stabilizer in combination with an ultraviolet-active cationic polymerization initiator. Can be. In addition, it was found that when the adhesive layer contained the quinolines, the connection resistance between the substrates via the film did not increase and could be kept constant.

Specific examples of the quinolines used according to the present invention include 2-methylquinoline, 3-methylquinoline, 4-methylquinoline,
Methylquinoline, 6-methylquinoline, 7-methylquinoline, and 8-methylquinoline, especially when the quinoline skeleton has an alkyl group, are expected to further enhance the stabilizing effect due to the electron donating effect.

In the present invention, the above quinolines as a stabilizer are added in an appropriate amount to the cationic polymerization initiator. Preferably, 0.001 to 1 mol of a quinoline is added to 1 mol of the cationic polymerization initiator. If the amount of the quinoline is less than about 0.001 mol per 1 mol of the cationic polymerization initiator, the storage stability at room temperature tends to be insufficient. On the other hand, when the amount of the quinoline exceeds about 1 mol per 1 mol of the cationic polymerization initiator, the cationically polymerizable composition tends not to be cured at a relatively low temperature and for a short time. Such a trend is due to Differential Scanning Calorime
ter: DSC). That is, in any case, the cationic polymerizable composition to which the quinolines are added in excess of the above-mentioned appropriate amount range tends to show an exothermic peak on the higher temperature side when the temperature is increased by scanning the temperature using DCS. Because it is in.

In the conductor circuit 20 shown in FIG. 1, a conductive material (28), which is usually in the form of particles, is dispersed in a cationically polymerizable composition. When the cationically polymerizable composition is cured, the conductive substances are in contact with each other between the conductors (10, 14) functioning as electrodes to electrically connect the electrodes (the conductive substance in FIG. 1). (24)). That is, the adhesive layer has conductivity (anisotropic conductivity) in the thickness direction.

The conductive material is generally a conductive metal or alloy (eg, silver, copper, nickel, gold, tin, zinc, platinum, palladium, iron, tungsten, molybdenum, solder, etc.), or graphite or graphitic carbon. Particles. However, the conductive material is not limited to the above, and the surface of the non-conductive particles may be coated with the above metal, alloy, graphite, or graphitic carbon.

In the cationically polymerizable composition of the present invention, the mixing ratio of the conductive substance is not particularly limited, but is usually 0.1 to 30% by volume, preferably 0.5 to 10% by weight, based on the weight of the composition. %, More preferably 1 to 5% by volume. If the compounding ratio of the conductive substance is less than about 0.1% by volume, the conductive particles may not be present on the electrode at the time of bonding. On the other hand, the mixing ratio of the conductive substance is about 30.
When the content exceeds the volume%, a short circuit between adjacent electrodes tends to easily occur.

Usually, since the cationically polymerizable composition of the present invention has a relatively high fluidity, a thermoplastic material is added as necessary to form a plastic and flexible adhesive film. can do. The thermoplastic material is desirably a thermoplastic elastomer in order to improve film formability, improve the impact resistance of the obtained adhesive film, and reduce internal stress caused by a curing reaction. In particular, a styrene-based thermoplastic elastomer is desirable. This is because heat resistance can be imparted to the adhesive film. Further, the styrene-based thermoplastic elastomer preferably has an epoxy group in the molecule. This is because the cohesive force of the obtained adhesive film can be improved by being incorporated into the curing reaction of the cationically polymerizable monomer. Styrene-based thermoplastic elastomers having an epoxy group in the molecule are commercially available from Daicel Chemical Industries, Ltd. under the trade names “Epofriend A1010” and “CT128”. However, instead of the elastomer, a thermoplastic resin (for example, a polystyrene resin) having a glass transition temperature (Tg) lower than the thermocompression bonding temperature in consideration of fluidity may be used.

The cationically polymerizable composition of the present invention may contain, in addition to the above components, components contained in a conventional cationically polymerizable composition. For example, a cationic polymerization accelerator,
Additives such as antioxidants or silane coupling agents,
Alternatively, a modifier such as a diol or a tackifier may be added to the cationically polymerizable composition.

The conductor circuit of the present invention is formed by, for example, a known method as follows. First, an anisotropic conductive adhesive film in which conductive particles are dispersed is attached to one of a pair of electronic circuit boards to be bonded, and then thermocompression-bonded. Next, after irradiating ultraviolet rays to the anisotropic conductive adhesive film crimped to one of the electronic circuit boards, the other of the electronic circuit boards is attached to the exposed surface of the adhesive film, and the conductors of both electronic circuit boards are aligned with each other. I do. Subsequently, when the two electronic circuit boards are further thermocompression-bonded via the anisotropic conductive adhesive film, a conductor circuit is obtained. At that time, according to the present invention, by using the quinolines of the above general formula, such thermocompression bonding can be completed at a relatively low temperature and a short time as described above.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but it goes without saying that the present invention is not limited to these examples. Preparation of Cationic Polymerizable Composition Example 1 First, on a cylindrical aluminum pan for preparation, start cyclopentadienyl iron (II) (xylene) hexafluoroantimonate (CpFeXySbF ₆ ) (ultraviolet-activated cationic polymerization) Agent) in 0.01 g of γ-butyrolactone (solvent).
The initiator solution was prepared by completely dissolving in addition to 03 g.
In addition, a liquid polyfunctional alicyclic epoxy resin having an epoxy equivalent of 176 (“ERL-4221” manufactured by Union Carbide)
2 g and quinoline (stabilizer) 0.001 g (0.36 mol per 1 mol of initiator) were mixed to prepare a monomer solution. Then, after adding the monomer solution to the initiator solution on the aluminum pan, the mixture was sufficiently stirred to prepare a cationically polymerizable composition.

Reference Example 1 A cationically polymerizable composition was prepared in the same manner as in Example 1 except that quinoline was not added.

Evaluation of Cationic Polymerizable Composition Each of the cationic polymerizable compositions prepared in Example 1 and Reference Example 1 was evaluated as follows. Thermal analysis About 10 mg of the cationically polymerizable composition was placed on a cylindrical aluminum pan for DCS measurement. Then, 400mW / cm
^Using a UV irradiator having an output of ² (Hamamatsu Photonics KK, UV spot light source L5662-01, equipped with an infrared cut filter), uniformly irradiate the composition with UV having a central wavelength of 365 nm for 15 seconds and start. The agent was activated. During the curing, the cationically polymerizable composition was maintained at a surface temperature of 30 ° C. or lower using dry air. This is to prevent the curing of the cationically polymerizable composition from being promoted by heat caused by infrared rays.

The thermal behavior of the cationically polymerizable composition was determined as follows. PERKIN ELMER DSC measurement device (DSC7 and Thermal Analysis Calorimeter TAC7 /
DX), 1) Immediately after UV irradiation 2) After standing at 25 ° C for 30 minutes in a dark place after UV irradiation, or 3) After standing at 100 ° C for 10 minutes in a dark place after UV irradiation, 10 ° C / min The cationically polymerizable composition is heated from 10 ° C. to 300 ° C. at a heating rate, and a) a reaction initiation temperature (T _onset (° C.)) called an _onset temperature of an exothermic peak at the time points 1) to 3) above; A) the peak temperature of the exothermic peak (T _peak (° C.)), and c) the integrated value of the exothermic peak (ΔH (J / g)) indicating the calorific value of the cationically polymerizable composition. Table 1 shows the results.

[0032]

[Table 1]

According to the results shown in Table 1, the initial calorific value of the cationically polymerizable composition of Example 1 even when the composition was left at 25 ° C. for 30 minutes after activation of the UV-activated cationic polymerization initiator by ultraviolet rays. Was almost maintained. Therefore, in the cationically polymerizable composition of Example 1, it became clear that the polymerization reaction was inhibited and the composition was kept stable. In addition, no DSC exothermic peak was observed after standing at 100 ° C. for 10 minutes. Therefore, it was found that the cationically polymerizable composition was sufficiently cured at 100 ° C.
Further, the cationically polymerizable composition of Example 1 has an exothermic peak temperature higher by at least 20 ° C. than that of Reference Example 1 immediately after irradiation with ultraviolet light. This result indicates that quinoline enhances the stability of the composition at room temperature. On the other hand, when the cationically polymerizable composition of Reference Example 1 was left at 25 ° C. for 0 minutes after activation of the ultraviolet ray-activated cationic polymerization initiator by ultraviolet rays, the calorific value decreased compared to immediately after the ultraviolet ray irradiation. It was clear that. Therefore, when quinoline was not present, the polymerization reaction of the polymerizable composition proceeded without inhibition, and it was found that the storage stability of the composition was poor.

Measurement of Gel Time Further, the time during which the cationically polymerizable composition forms a gel by heating (gel time) was measured as follows. 2g
Was irradiated with ultraviolet rays in the same manner as in the thermal analysis test. Thereafter, this cationically polymerizable composition was placed in a cylindrical aluminum pan. Next, the aluminum pan was placed on a hot plate at 40 ° C., and the time at which a gel was formed at that temperature was measured. The formation of the gel was determined by the presence or absence of an increase in the viscosity of the cationically polymerizable composition. Further, the rise in the viscosity at 40 ° C. is 1
When no observation was observed even after the elapse of time, the hot plate was heated to 100 ° C. and the time required for gel formation at that temperature was measured. Table 2 shows the gel time.

[0035]

[Table 2]

According to the results shown in Table 2, in the case of the cationically polymerizable composition of Example 1, gel formation does not start even if heated at 40 ° C. for 1 hour, but gel formation starts at 100 ° C. Do you get it. On the other hand, it was found that the cationically polymerizable composition of Reference Example 1 started to gel at 40 ° C. Therefore, according to the present invention, when an appropriate amount of a quinoline is added in combination with an ultraviolet ray-activated polymerization initiator, the pot life (open time) from ultraviolet irradiation to heat curing by heat treatment becomes longer. In addition, it has been clarified that quinolines do not inhibit the polymerization reaction at all during heat curing by heat treatment.

The effects of the present invention in thermal cationic polymerization will be described with reference to the following examples and reference examples. Example 2 Instead of cyclopentadienyliron (II) (xylene) hexafluoroantimonate (CpFeXySbF ₆ ) which is an ultraviolet-activated cationic polymerization initiator, bismesityleneiron (II) bis which is a thermal cationic polymerization initiator Using {Tris (trifluoromethylsulfonylmeside)} (MeFeMeMtd), and instead of 2g of polyfunctional alicyclic epoxy resin,
A cationically polymerizable composition was prepared in the same manner as in Example 1, except that 2 g of a bisphenol A type epoxy resin having an epoxy equivalent of 189 (YL980 manufactured by Yuka Shell Epoxy Co., Ltd.) was used. In this case, the amount of quinoline is 0.87 mol per 1 mol of the thermal cationic polymerization initiator.

Reference Example 2 A cationically polymerizable composition was prepared in the same manner as in Example 2 except that quinoline was not added.

For each of the cationically polymerizable compositions prepared in Example 2 and Reference Example 2, thermal analysis and gel time were measured in the same manner as in Example 1. However, D of thermal analysis
In the SC measurement, instead of the above conditions 1) to 3), a) the reaction initiation temperature (T
_onset (° C)), b) Peak temperature of exothermic peak (T _peak
(° C.)) and c) the integrated value of the exothermic peak (ΔH (J /
g)) was measured. 4) Immediately after mixing the monomer solution containing the quinoline stabilizer and the bisphenol A type epoxy resin with the polymerization initiator solution; 5) After mixing the monomer solution with the polymerization initiator solution,
When left at 25 ° C. for 30 minutes in a dark place, 6) After mixing the monomer solution and the polymerization initiator solution,
When left at 150 ° C. for 10 minutes in a dark place. When measuring the gel time, if no increase in the viscosity of the composition at 40 ° C. was observed even after 1 hour, then the hot plate was heated to 150 ° C. instead of heating to 100 ° C. The time at which the gel formed at that temperature was measured. Table 3 shows the results.

[0040]

[Table 3]

According to the results shown in Table 3, the cationically polymerizable composition of Example 2 showed almost no initial calorific value even after being left at 25 ° C. for 20 minutes after activation of the heat-activated cationic polymerization initiator. It turned out that we maintained. Therefore, in the cationically polymerizable composition of Example 2, it became clear that the polymerization reaction was inhibited and the composition was kept stable. Also,
After standing at 150 ° C. for 10 minutes, no DSC exothermic peak was observed. Therefore, it was found that the cationically polymerizable composition was sufficiently cured at 150 ° C. On the other hand, when the cationically polymerizable composition of Reference Example 2 was left at 25 ° C. for 30 minutes after activation of the heat-activated cationic polymerization initiator, the calorific value was clearly smaller than immediately after mixing. It became. Therefore, it was found that when quinoline was not present, the polymerization reaction proceeded without being inhibited, and the composition had poor storage stability.

For the cationically polymerizable compositions of Example 2 and Reference Example 2, the gel formation time was measured in the same manner as in Example 1. Table 4 shows the results.

[0043]

[Table 4]

According to the results shown in Table 4, it was found that in the case of the cationically polymerizable composition of Reference Example 2, a gel started to form at 40 ° C. In addition, in the case of the cationically polymerizable composition of Example 2, it was found that no gel was formed at 40 ° C., and formation started at 150 ° C. Therefore, according to the present invention, it has been clarified that an appropriate amount of quinoline contributes to stabilization of the cationically curable composition, and that the quinoline does not inhibit the polymerization reaction during heat curing by heat treatment.

Next, the effect of the anisotropic conductive adhesive film of the present invention containing a UV-activated cationic polymerization initiator will be described. Production of Anisotropic Conductive Adhesive Film Example 3 Anisotropic conductive adhesive films were produced according to the amounts shown in Table 5 as follows. First, an epoxy equivalent of 219
Epoxy resin, epoxy equivalent 178 epoxy resin,
Two kinds of thermoplastic elastomers having epoxy groups in the molecule and bisphenoxyethanolfluorene were uniformly dissolved in tetrahydrofuran (THF). Then
The conductive particles were added to this solution, and the resulting mixture was dispersed by stirring to prepare a monomer solution. On the other hand, two types of UV-activated cationic polymerization initiators, namely, cyclopentadienyl iron (II) (xylene) hexafluoroantimonate (CpFeXySbF ₆ ) and cyclopentadienyl iron (II)
(Cumene) hexafluorophosphate (CpFeCmPF ₆ )
, Quinoline (stabilizer), di-t-butyl oxalate (reaction accelerator), silane coupling agent and THF were uniformly mixed in a light-shielding bottle to prepare a polymerization initiator solution. Next, the polymerization initiator solution and the monomer solution were uniformly mixed to prepare a mixed solution. The mixed solution was coated on a silicone-treated polyester film substrate using a knife coater. Thereafter, the coating of the mixed solution was dried together with the polyester film by heating at 55 ° C. for 13 minutes to obtain a 38 μm thick anisotropic conductive adhesive film.

Example 4 As shown in Table 5, an anisotropic conductive adhesive film having a thickness of 38 μm was produced in the same manner as in Example 3 except that the amount of quinoline was increased from 0.008 g to 0.0016 g. .

Reference Example 3 An anisotropic conductive adhesive film having a thickness of 38 μm was produced in the same manner as in Example 3 except that quinoline was not added.

[0048]

[Table 5] Note: 1) Eporito (trademark) GT401 (manufactured by Daicel Chemical Industries, Ltd.) 2) Epicoat (trademark) 152 (manufactured by Yuka Shell Epoxy) 3) Epofriend (trademark) A1010 (manufactured by Daicel Chemical Industries, Ltd.) 4 ) Epofriend (trademark) CT128 (manufactured by Daicel Chemical Industries, Ltd.) 5) BPEF (manufactured by Osaka Gas Chemical Co., Ltd.) 6) 6GNM5-Ni (manufactured by Nippon Chemical Industry Co., Ltd .; gold-plated nickel particles; average particle size: 6 μm) 7 ) Irgacure (trademark) 261 (Nippon Ciba Geigy Co., Ltd.) 8) Wako Pure Chemical Industries, Ltd. 9) γ-glycidoxypropyltrimethoxysilane (Nippon Unicar Co., Ltd. “A187”)

Evaluation of Anisotropic Conductive Adhesive Film Next, as shown below, using each of the anisotropic conductive adhesive films produced in Examples 3 to 4 and Reference Example 3, a circuit connection having a conductor circuit was used. After preparing the test piece, the connection resistance between the circuit boards via the anisotropic conductive adhesive film was measured, and the performance was evaluated.

Preparation of Circuit Connection Specimen A 200 μm-wide copper conductor having a thickness of 3 mm was placed on a 0.6 mm thick glass epoxy substrate (“FR4” manufactured by Kyoden Co., Ltd.).
196 conductors plated with 5 μm gold are 400 μm
Printed wiring board (PC)
B) was prepared. Together with the polyester film substrate,
The sheet was cut into a width of 3 mm and a length of 4 cm, and affixed on the surface of the printed wiring board (PCB) such that the anisotropic conductive adhesive film faced the conductor. The printed wiring board (PCB) to which the anisotropic conductive adhesive film / polyester film was attached was heated and pressed for 4 seconds while maintaining the temperature at 50 ° C., and then the base material was removed to expose the anisotropic conductive adhesive film. . Next, the exposed surface of the anisotropic conductive adhesive film was irradiated with ultraviolet rays for 10 seconds using the above-described ultraviolet irradiation device. During the irradiation, the anisotropic conductive adhesive film was air-cooled so as not to apply heat, thereby suppressing the promotion of thermosetting.

Separately, a flexible printed wiring board (FPC) printed wiring is formed by arranging 196 conductive wires of copper of 200 μm width plated with tin of 18 μm thickness on a polyimide film of 75 μm thickness at a pitch of 400 μm. A board was prepared, and an anisotropic conductive adhesive film on the printed wiring board was attached and fixed on the surface on which the conductive wires were arranged. At that time, the conductors of the PCB and the FPC were aligned with each other. Thereafter, while the anisotropic conductive adhesive film was heated to 85 ° C., a pressure of 1.2 MPa was applied to the anisotropic conductive adhesive film via the PCB and the FPC for 12 seconds to perform thermocompression bonding. (Conductor circuit) was obtained.

Next, the connection resistance between the FPC and the PCB ring of the circuit connection test piece was measured using MILLIOHMMETER manufactured by HEWLETT PACKERD under the following conditions 7) and 8). Table 6 shows the measured maximum values of the connection resistance. 7) When FPC and PCB are thermocompression-bonded immediately after UV irradiation. 8) After UV irradiation, the anisotropic conductive adhesive film is left in an atmosphere of 30 ° C. and 70% RH for 30 minutes.
When thermocompression bonding with CB

[0053]

[Table 6]

According to the results shown in Table 6, the anisotropic conductive adhesive films of Examples 3 and 4 according to the present invention were
It can be seen that the maximum value of the connection resistance hardly changes even after being left for 30 minutes in an atmosphere of 30 ° C. and 70% RH after the irradiation of the ultraviolet rays. In contrast, the anisotropic conductive adhesive film of Reference Example 3 has a large change in the maximum value of the connection resistance.

[0055]

The cationically polymerizable composition of the present invention has excellent stability because it contains quinolines as a stabilizer, and can be prepared as a one-pack type curing composition. At the time of curing, the polymerization reaction of the cationically polymerizable monomer is not impaired. Further, the cationically polymerizable composition of the present invention can be thermocompression bonded to an adherend at a relatively low temperature and for a short time, and even after a long time has elapsed since the start of curing.
Since it exhibits excellent thermocompression bonding properties, it is suitable for crimping an adherend having a conductor on its surface, for example, a printed wiring board.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a conductor circuit of the present invention.

[Explanation of symbols]

10, 14 ... conductor, 12, 18 ... electronic circuit board, 20 ...
Conductive circuit, 24, 28 ... conductive material.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C09J 7/02 C09J 7/02 Z 9/02 9/02 129/10 129/10 163/00 163/00 H01B 1 / 22 H01B 1/22 D 1/24 1/24 D (72) Inventor Hiroaki Yamaguchi 3-8-8 Minamihashimoto, Sagamihara City, Kanagawa Prefecture Sumitomo 3M Corporation (72) Inventor Tetsu Kitamura 3- Minamihashimoto, Sagamihara City, Kanagawa Prefecture 8-8 Sumitomo 3M Co., Ltd. F-term (reference) 4J002 CD021 CD051 DA028 DC008 EU057 EZ006 FD037 FD118 FD156 GJ00 GQ02 4J004 AA02 AA08 AA13 AB05 AB07 CA06 CC02 FA05 4J036 AD08 AJ09 FA12 EC04 EC06 EC04 EC04 EC071 EC072 GA11 HA036 HA066 HA076 HC21 HD41 JA09 JA12 JB02 JB08 KA12 KA13 KA27 KA32 LA01 LA05 MA02 MA10 MB03 NA10 PA18 PA30 PA32 5G301 DA03 DA05 DA06 DA07 DA09 DA10 DA11 DA12 DA13 DA14 DA19 DA42 DA57 DD08

Claims (4)

[Claims] 1. A cationic polymerizable monomer, a cationic polymerization initiator, and a stabilizer comprising quinolines,
A cationically polymerizable composition comprising: wherein the quinolines are represented by the following formula: (Wherein, Rs are each independently a hydrogen atom or an alkyl group). 2. A thermoplastic material having an epoxy group in a molecule, a cationically polymerizable monomer, a cationic polymerization initiator, and a stabilizer comprising quinolines,
An adhesive film comprising: wherein the quinoline is represented by the following formula: (Wherein, R is each independently a hydrogen atom or an alkyl group). 3. The adhesive film according to claim 2, wherein a conductive substance is dispersed. 4. An adhesive film containing a dispersed conductive substance, while bonding two adherends each having a conductor on the surface thereof, bringing the conductive substances into contact with each other between the conductors, thereby connecting the conductors to each other. A conductive circuit that is electrically joined, wherein the adhesive film is a thermoplastic material having an epoxy group in a molecule, a cationic polymerizable monomer, a cationic polymerization initiator, and a stabilizer comprising quinolines,
Wherein the quinolines are of the following formula: (Wherein, Rs are each independently a hydrogen atom or an alkyl group).