KR20160115909A - Reaction rate measurement method for acrylic adhesive, and acrylic adhesive - Google Patents

Abstract

A reaction rate measuring method capable of measuring the reaction rate of an acrylic adhesive with good precision even with a small amount of sample, and an acrylic adhesive. A compound having a fluorene skeleton is used as a reference material, a sample solution containing an acrylic adhesive is separated by liquid chromatography, and an unreacted radically polymerizable compound is detected by an ultraviolet detector. Since a compound having a fluorene skeleton exhibits high sensitivity to an ultraviolet detector, the reaction rate can be measured with good precision even with a very small amount of sample. Further, since the compound having a fluorene skeleton does not participate in the curing reaction of the acrylic adhesive, it is possible to mix it in advance with the acrylic adhesive.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of measuring the reaction rate of an acrylic adhesive, and an acrylic adhesive,

The present invention relates to a method for measuring the reaction rate of an acrylic adhesive containing a radical polymerizable compound, and an acrylic adhesive. The present application claims priority based on Japanese Patent Application No. 2014-18388 filed on February 3, 2014, the entirety of which is incorporated herein by reference.

As an electric circuit material in the past, anisotropic conductive film (ACF) and the like are widely used. As a cause of the defect of the ACF, variation of the degree of curing in the circuit electrode is presumed. In the anisotropic conductive connection, a plurality of electrodes are collectively and uniformly connected, so that it is considered that there is a difference in the reaction rate at the portion between the electrode having relatively high thermal conductivity and the electrode having relatively low thermal conductivity.

However, in the conventional analysis using DSC, FT-IR, etc., it is difficult to accurately measure the reaction rate of the minute domains such as the electrode surface and the electrode because the amount of the sample required is large.

Japanese Patent Application Laid-Open No. 2010-251789

The present invention has been proposed in view of such conventional circumstances, and provides a reaction rate measuring method and an acrylic adhesive that can measure the reaction rate of an acrylic adhesive with good precision even with a small amount of sample.

As a result of intensive studies, the inventor of the present invention has found that the use of a compound having a fluorene skeleton as a reference material enables the reaction rate measurement to be performed with high accuracy even with a very small amount of sample.

That is, in the reaction rate measuring method according to the present invention, a compound having a fluorene backbone represented by the following formula (1) is used as a reference material, a sample solution containing an acrylic adhesive is separated by liquid chromatography, To thereby detect an unreacted radically polymerizable compound.

[Chemical Formula 1]

Wherein R ₁ is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms, R ₂ is a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, And a hydroxyalkoxy group having 1 to 3 carbon atoms.

The acrylic adhesive according to the present invention is characterized by containing a compound having a fluorene skeleton represented by the above formula (1), a radically polymerizable compound, and a reaction initiator.

The anisotropic conductive adhesive according to the present invention is characterized in that conductive particles are dispersed in the acrylic adhesive.

According to the present invention, since a compound having a fluorene skeleton exhibits high sensitivity to an ultraviolet detector, the reaction rate can be measured with high accuracy even with a very small amount of sample. Further, since the compound having a fluorene skeleton does not participate in the curing reaction of the acrylic adhesive, it is possible to mix it in advance with the acrylic adhesive.

1 is a chromatogram showing an example of an analysis result of an acrylic adhesive before curing.
2 is a chromatogram showing an example of an analysis result of the acrylic adhesive after curing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings in the following order.

1. Measurement of reaction rate of acrylic adhesive

2. Acrylic adhesive

3. Example

<1. Method of measuring reaction rate of acrylic adhesive>

The reaction rate measurement method of the acrylic adhesive relating to the present embodiment is a method of measuring the reaction rate of an acrylic adhesive using a compound having a fluorene skeleton represented by the following formula (1) as a standard material, separating a sample solution containing an acrylic adhesive by liquid chromatography, Unreacted radically polymerizable compound is detected by a detector.

(2)

In the formula, R ₁ represents a hydrogen atom (-H), an alkyl group having 1 to 3 carbon atoms (-C _n H _{2n +1} : n = 1 to 3), an alkoxy group having 1 to 3 carbon atoms (-OC _n H _{2n + 1} : n = 1 to 3), R ₂ is a group selected from the group consisting of a hydroxyl group (-OH), a hydroxyalkyl group having 1 to 3 carbon atoms (-C _n H _2n OH: n = 1 to 3) And a hydroxyalkoxy group having 1 to 3 carbon atoms (-OC _n H _2n OH: n = 1 to 3).

(1) Specific examples of the compound having a fluorene skeleton represented by the following formula, when the non-Made rust ethanol fluorene _{(BPEF: R 1 = H,} R 2 = OC 2 H 4 OH), bisphenol fluorene (BPF: R ₁ = H, R ₂ = OH), and biscresol fluorene (BCF: R ₁ = CH ₃ , R ₂ = OH). A compound having a fluorene skeleton represented by the formula (1) shows high sensitivity to an ultraviolet detector because of its high ability to absorb ultraviolet rays, and a reaction rate can be measured with high accuracy even with a very small amount of sample.

In addition, there are dibutylhydroxytoluene (BHT), benzotriazole (BTZ) and the like as a general internal standard substance which can be detected by an ultraviolet detector, but the detection sensitivity is insufficient and a large amount should be added. In addition, the BHT is low in versatility, because the peak detection sites overlap with bisphenoxyethanol fluorene acrylate (BPEFA) and BTZ with 4-hydroxybutyl acrylate (4-HBA).

Liquid chromatography is a high performance liquid chromatography (HPLC) method in which a sample solution is passed through a separation column packed with a separating agent and separated from a difference in easiness of distribution, .

Examples of the separating agent (filler) include a chemically bonded silica gel, a porous polymer, an ion exchange resin, etc. bonded by a group such as silica gel, octadecyl group, and cyanopropyl group having a particle diameter of about 2 to 30 μm for HPLC .

The ultraviolet detector is not particularly limited as long as ultraviolet light is irradiated to the sample solution and the absorbance by the sample solution is measured. An ultraviolet absorbance detector commonly used in analysis by HPLC can be used.

Next, details of the reaction rate measurement will be described. In the present technology, a predetermined amount of a compound having a fluorene skeleton may be added to a sample solution of an acrylic adhesive even if a predetermined amount of a compound having a fluorene skeleton is added to the acrylic adhesive in advance. As the solvent for dissolving the acrylic adhesive, acetonitrile, acetone and the like can be used.

Fig. 1 and Fig. 2 are chromatograms showing an example of the analysis results of the acrylic adhesive before and after curing, respectively. The peak intensity of the chromatogram obtained by the ultraviolet detector is usually expressed by the peak area or the peak height. Hereinafter, a calculation method of the reaction rate due to the peak height will be described.

First, the intensity ratio of the internal standard substance to the unreacted monomer is determined from the chromatogram of the acrylic adhesive before curing and the acrylic adhesive after complete curing. For example, the reaction rate before the curing is set to 0% Thus, a relationship line between the intensity ratio and the reaction rate is created. Then, from the chromatogram of the unknown sample, the intensity ratio between the internal standard substance and the unreacted monomer is obtained, and the reaction rate can be obtained from the created relationship line.

By using the compound having the fluorene backbone represented by the formula (1) as the reference material in this way, the reaction rate can be measured with high accuracy even with a very small amount of sample.

<2. Acrylic adhesive>

The acrylic adhesive relating to the present embodiment contains a compound having a fluorene skeleton represented by the following formula (1), a radically polymerizable compound, and a reaction initiator.

(3)

In the formula, R ₁ represents a hydrogen atom (-H), an alkyl group having 1 to 3 carbon atoms (-C _n H _{2n +1} : n = 1 to 3), an alkoxy group having 1 to 3 carbon atoms (-OC _n H _{2n + 1} : n = 1 to 3), R ₂ is a group selected from the group consisting of a hydroxyl group (-OH), a hydroxyalkyl group having 1 to 3 carbon atoms (-C _n H _2n OH: n = 1 to 3) And a hydroxyalkoxy group having 1 to 3 carbon atoms (-OC _n H _2n OH: n = 1 to 3).

(1) Specific examples of the compound having a fluorene skeleton represented by the following formula, when the non-Made rust ethanol fluorene _{(BPEF: R 1 = H,} R 2 = OC 2 H 4 OH), bisphenol fluorene (BPF: R ₁ = H, R ₂ = OH), and biscresol fluorene (BCF: R ₁ = CH ₃ , R ₂ = OH).

Hereinafter, an anisotropic conductive adhesive in which conductive particles are dispersed in an acrylic adhesive will be described. The compound having a fluorene skeleton represented by the formula (1) is not decomposed at the time of thermocompression bonding even when mixed with an anisotropic conductive adhesive, and does not participate in the curing reaction, . Therefore, by using this anisotropic conductive adhesive, it is possible to accurately measure the reaction rate of the minute domains such as the electrode surface and the electrode.

The compounding amount of the compound having a fluorene skeleton is preferably 0.01 wt% or more and 5.0 wt% or less, and more preferably 0.2 wt% or more and 1.0 wt% or less. When the blending amount is too small, the measurement peak becomes small, and when the blending amount is too large, the characteristics as the anisotropic conductive film deteriorate.

Examples of the radical polymerizable compound include monofunctional (meth) acrylate monomers, polyfunctional (meth) acrylate monomers, or modified monofunctional monomers having epoxy groups, urethane groups, amino groups, ethylene oxide groups and propylene oxide groups introduced into them Polyfunctional (meth) acrylate monomers can be used. The radical polymerizable compound may be used in either a monomer or an oligomer state, or a monomer and an oligomer may be used in combination.

Examples of the (meth) acrylate monomer include (meth) acrylate resins having at least one (meth) acryloyl group in at least one molecule, and modifications thereof. Examples of the denatured materials include, but are not limited to, tetrahydrofurfuryl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate , Ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diacrylate, pentaerythritol triacrylate, ethoxylated isocyanuric acid triacrylate, and the like. These may be used alone or in combination of two or more.

As the reaction initiator, an organic peroxide, a photo radical polymerization initiator, or the like can be used. As the organic peroxide, one or more of diacyl peroxide, dialkyl peroxide, peroxydicarbonate, peroxy ester, peroxyketal, hydroperoxide, silyl peroxide and the like can be used. Examples of the photo radical polymerization initiator include benzoin ethers such as benzoin ethyl ether and isopropyl benzoin ether; benzyl ketals such as benzyl and hydroxycyclohexyl phenyl ketone; ketones and derivatives such as benzophenone and acetophenone; Oacic acid, oceansaltone, bisimidazoles, and the like.

As the conductive particles, conductive particles used in conventional anisotropic conductive films can be used. For example, the surface of resin particles such as gold particles, silver particles, metal particles such as nickel particles, benzoguanamine resin or styrene resin, , Metal coated resin particles coated with a metal such as nickel or zinc, or the like can be used. The average particle diameter of such conductive particles is usually 1 to 10 占 퐉, and more preferably 2 to 6 占 퐉.

The anisotropic conductive adhesive may contain a film-forming resin, a silane coupling agent, a phosphoric acid ester, an inorganic filler, a stress relaxation agent, and the like. Examples of the film-forming resin include phenoxy resin, polyvinyl acetal resin, polyvinyl butyral resin, alkylated cellulose resin, polyester resin, acrylic resin, styrene resin, urethane resin, and polyethylene terephthalate resin. Examples of the silane coupling agent include γ-glycidopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N- -aminopropyltrimethoxysilane, -methacryloxypropyltrimethoxysilane, and the like.

By using such an anisotropic conductive adhesive, it is possible to measure the reaction rate of the minute domains such as the electrode surface and the electrodes with good precision, so that stable bonding conditions can be obtained in a short time.

Example

<3. Examples>

Hereinafter, an embodiment of the present invention will be described. In this example, the reaction rate of an acrylic anisotropic conductive adhesive was measured by high performance liquid chromatography (HPLC) using bisphenolethanol fluorene (BPEF) as an internal standard substance, and the standard deviation was evaluated. The standard deviation of the reaction rates measured by DSC (differential scanning calorimetry) and FT-IR (Fourier transform infrared spectroscopy) was also evaluated as a comparative example. In addition, the present technology was used to measure the reaction rate between the wirings of the mounting body and the wirings, and evaluation of the connection reliability was performed. In addition, the addition amount of BPEF was examined. The present invention is not limited to these examples.

The anisotropic conductive film and the mounting body were produced as follows.

[Production of anisotropic conductive film]

The following anisotropic conductive adhesive was used. 40 parts by mass of a phenoxy resin (trade name: YP50, Shin Nittsu Sumikin Kagaku K.K.), 40 parts by mass of a polyurethane (trade name: N-5196, manufactured by Nippon Polyurethane Coatings Co., Ltd.) 2 parts by mass of a silane coupling agent (trade name: PM-2, manufactured by Nippon Kayaku Co., Ltd.), 2 parts by mass of a silane coupling agent (trade name: A-187, Momentive Performance Materials Co., 5 parts by mass of acrylic acid ester (trade name: SG-P3, manufactured by Nagase Chemtex Co., Ltd.), 5 parts by mass of diacyl peroxide (trade name: PEROIL L, available from Nippon Oil Co., Ltd.) , And 3 parts by mass of conductive particles having an average particle size (D50) of 10 mu m (Sekisui Chemical Co., Ltd.) were added in a total amount of 100 parts by mass. A composition prepared by adding a predetermined amount of BPEF to this composition was applied to PET (Polyethylene Terephthalate) And dried by hot air at 60 DEG C for 4 minutes to obtain an anisotropic conductive adhesive film having a thickness of 16 mu m.

[Production of mounting body]

As the evaluation substrate, an FPC (200 탆 P, L / S = 1/1, PI / Cu = 25/12 탆, Au plating) and a glass substrate (ITO solid glass, 10 Ω / ) Was used to produce a mounting body. An anisotropic conductive film was pasted on the glass substrate and heated and pressed under the conditions of 45 DEG C, 1 MPa, and 2 seconds, PET was peeled off, and pressure bonding was performed. An FPC was placed on the anisotropic conductive film, and heated and pressed under the conditions of a predetermined temperature, 2 MPa, and 5 seconds to obtain a mounting body.

<3.1 Standard deviation of measured value>

As described above, the anisotropic conductive film containing 0.5 wt% of BPEF was used to prepare a mounting body, and the reaction rate of the anisotropic conductive film was measured using HPLC, DSC, and FT-IR. The FPC was peeled off from the mounting body, and the measurement sample was sampled from the wiring of 2.0 mm x 0.2 mm and the wiring of 2.0 mm x 0.2 mm.

[HPLC]

As a HPLC analysis apparatus, UPLC (UV detector connection) manufactured by Waters was used. 0.005 mg of the sample for measurement was dissolved in acetonitrile, and this was injected into a separation column (10 cm, 40 캜) to obtain a chromatogram. The analysis conditions were as follows.

Acetonitrile room temperature extraction-HPLC / DAD method

Extraction: 30 占 퐇 of acetonitrile

Gradient conditions: A 60%, B 40% (hold for 1 minute), A 1%, B 99% (hold for 6 minutes), A = H ₂ O, B = ACN

Flow rate: 0.4 ml / min

Injection amount: 5 μl

Analysis wavelength: 210-400 nm

From the chromatogram thus obtained, the measurement intensity ratio between BPEF and acrylic monomer was determined, and the reaction rate was determined from the relationship between the measurement intensity ratio of BPEF and acrylic monomer prepared beforehand and the reaction rate. This operation was repeated three times in total.

As shown in Table 1, the measurement results of the reaction rate when the compression temperature was 130 ° C were 78.5% for the first time, 79.4% for the second time, and 79.2% for the third time, and the standard deviation was 0.4726. The measurement results of the reaction rate when the compression temperature was 140 캜 were 86.3% for the first time, 86.8% for the second time and 85.2% for the third time, and the standard deviation was 0.8185. The results of the measurement of the reaction rate when the compression temperature was 150 ° C were 91.1% for the first time, 92.0% for the second time and 91.0% for the third time, and the standard deviation was 0.5508.

[DSC]

Using a differential thermal analyzer (DSC6200, Seiko Instruments Inc.), 5.0 mg of a sample for measurement was heated from 30 占 폚 to 250 占 폚 at 10 占 폚 / min to obtain a DSC chart.

The uncured (pre-crimped) sample was taken as a reference. The difference between the calorific value of the uncured sample and the calorific value of the unknown sample after compression was determined and the calorific value of the uncured sample was set at 1 to calculate the reaction rate of the unknown sample. Measurement of the unknown sample was performed three times (N = 3). The calorific value was obtained from the area of the DSC chart.

As shown in Table 1, the results of the measurement of the reaction rate when the compression temperature was 130 ° C were 72.0% for the first time, 83.2% for the second time, and 75.7% for the third time, and the standard deviation was 5.7064. The results of the measurement of the reaction rate when the compression temperature was 140 캜 were 82.6% for the first time, 78.9% for the second time, and 88.1% for the third time, and the standard deviation was 4.6293. The measurement results of the reaction rate when the compression temperature was 150 ° C were 94.2% for the first time, 86.8% for the second time and 90.2% for the third time, and the standard deviation was 3.7041.

[FT-IR]

0.02 mg of a sample for measurement was measured by a transmission method using a Fourier transform infrared spectrophotometer (FT / IR-4100, manufactured by Nihon Bunko).

The reaction rate of the unknown sample was calculated from the ratio between the measurement intensity of the acrylic monomer (unsaturated group) of the uncured (pre-compression) sample and the measurement intensity of the acrylic monomer (unsaturated group) of the unknown sample after compression. Measurement of the unknown sample was performed three times (N = 3).

As shown in Table 1, the results of the measurement of the reaction rate when the compression temperature was 130 ° C were 68.7% for the first time, 79.6% for the second time and 74.2% for the third time, and the standard deviation was 5.4501. The results of the measurement of the reaction rate when the compression temperature was 140 캜 were 77.8% for the first time, 82.0% for the second time, and 89.7% for the third time, and the standard deviation was 6.0352. The results of the measurement of the reaction rate when the compression temperature was 150 ° C were 88.8% for the first time, 87.3% for the second time, and 93.8% for the third time, and the standard deviation was 3.4034.

As shown in Table 1, in the measurement using DSC and FT-IR, the standard deviation of the measured value became large and the precision was low. In addition, a large amount of sample is required, and it is difficult to measure the reaction rate between wirings and wirings as described later. On the other hand, in the measurement using HPLC-UV detection, it was possible to measure the reaction rate with a high precision with a small amount of sample by BPEF having high sensitivity to UV detection.

&Lt; 3.2 Measurement of reaction rate between wiring and wiring in a mounting body &gt;

As described above, a packaging material was produced using an anisotropic conductive film containing 0.5 wt% of BPEF, and the reaction rate of the anisotropic conductive film was measured by HPLC. The FPC was peeled off from the mounting body, and a sample for measurement on a wiring of 2.0 mm x 0.2 mm, a sample for measurement between wiring of 2.0 mm x 0.2 mm, and a sample for measurement between wiring and wiring were sampled.

[HPLC]

As a HPLC analysis apparatus, UPLC (UV detector connection) manufactured by Waters was used. 0.005 mg of the sample for measurement was dissolved in acetonitrile, and this was injected into a separation column (10 cm, 40 캜) to obtain a chromatogram. The analysis conditions were as follows.

Acetonitrile room temperature extraction-HPLC / DAD method

Extraction: 30 占 퐇 of acetonitrile

Gradient conditions: A 60%, B 40% (hold for 1 minute), A 1%, B 99% (hold for 6 minutes), A = H ₂ O, B = ACN

Flow rate: 0.4 ml / min

Injection amount: 5 μl

Analysis wavelength: 210-400 nm

From the chromatogram thus obtained, the measurement intensity ratio between BPEF and acrylic monomer was determined, and the reaction rate was determined from the relationship between the measurement intensity ratio of BPEF and acrylic monomer prepared beforehand and the reaction rate. The above operations were repeated three times in total to obtain an average value.

An environmental test (60 DEG C, 95%, 500 hours) was also performed on a package made using an anisotropic conductive film containing 0.5 wt% of BPEF, and the conduction resistance was measured. The conduction resistance was measured by a four-terminal method using a digital multimeter (Digital Multimeter 7561, manufactured by Yokogawa Electric KK). In the evaluation of the reliability test, "NG" was defined as a conduction resistance of 3 Ω or more, and "OK" as a conduction resistance of 3 Ω or less.

As shown in Table 2, when the compression temperature was 130 占 폚, the reaction rate on the wiring was 75%, the reaction rate between the wirings was 82%, and the reaction rate between the wirings and wiring was 80%. When the compression temperature was 140 占 폚, the reaction rate on the wiring was 83%, the reaction rate between the wirings was 89%, and the reaction rate between the wiring and the wiring was 86%. When the compression temperature was 150 ° C, the reaction rate on the wiring was 88%, the reaction rate between the wirings was 93%, and the reaction rate between the wiring and the wiring was 90%.

As shown in Table 2, it can be seen that the wiring pattern tends to be harder to cure ACF as compared with the wiring, because heat leakage is large due to the influence of high thermal conductivity of a metal such as copper and no heat accumulation occurs. As described above, in the present technology, since a small amount of sample is required, local reaction rates such as interconnection and interconnection can be measured with good precision.

&Lt; Addition amount of 3.3 BPEF &gt;

Next, the effect of the amount of BPEF added to the anisotropic conductive film was examined. The anisotropic conductive film and the mounting body were the same as those described above, and the amount of BPEF added to the anisotropic conductive film was changed to evaluate the appearance, fill strength, indentation property, and easiness of measurement of the anisotropic conductive film portion of the mounting body did.

The evaluation of the appearance of the anisotropic conductive film portion of the mounting body was made by observing with naked eyes the case where no air bubbles exist, the case where small air bubbles are present, the case where large air bubbles exist, the case where air bubbles are present, Quot; x &quot;. The peel strength (JIS K6854) of the mounting body was evaluated as &quot;? &Quot; when the 90 DEG pitch strength was 10 N / 25 mm or more, &quot;Quot; and the case where the 90 DEG pitch strength was less than 6N / 25 mm was evaluated as &quot; DELTA &quot; when the 90 DEG pitch strength was less than 6N / 25 mm and less than 8N / 25 mm. In addition, evaluation of the indentation property was evaluated as &quot;? &Quot; when the conduction resistance of the mounting body was 1? Or less, &quot;? &Quot;, 1 &amp; cir &amp; The conduction resistance was measured by a four-terminal method using a digital multimeter (Digital Multimeter 7561, manufactured by Yokogawa Electric KK). In the evaluation of ease of measurement, the case where the peak of the chromatogram is easily seen by visual observation is indicated as &quot;? &Quot;, the case where the peak is normal is indicated by &quot; O &quot;, the case where the peak is not easily seen is indicated by &Quot; x &quot;.

As shown in Table 3, when the addition amount of BPEF was 0.01 wt%, the appearance was evaluated as ⊚, the evaluation of the peel strength as ⊚, the evaluation of indentation as ⊚, and the ease of measurement as △. When the addition amount of BPEF was 0.1 wt%, evaluation of appearance was evaluated as?, Evaluation of peel strength was evaluated as?, Evaluation of indentation property as?, And ease of measurement as?. When the addition amount of BPEF was 0.2 wt%, the appearance was evaluated as ⊚, the evaluation of the peel strength was evaluated as ◎, the evaluation of indentation property was evaluated as ◎, and the measurement was easy. When the addition amount of BPEF was 0.5 wt%, the appearance was evaluated as?, The peel strength evaluated?, The indentation evaluated as?, And the ease of measurement was evaluated as?. When the addition amount of BPEF was 1.0 wt%, the evaluation of appearance was ⊚, evaluation of peel strength was ◎, evaluation of indentation property was ○, and ease of measurement was ◎. When the addition amount of BPEF was 5.0 wt%, the appearance was evaluated as O, the evaluation of peel strength was evaluated as?, The evaluation of indentation property was as?, And the ease of measurement was as?. When the addition amount of BPEF was 10.0% by weight, the appearance was evaluated as?, The evaluation of the peel strength was evaluated as?, The evaluation of indentation property was evaluated as?, And the ease of measurement was evaluated as?. When the addition amount of BPEF was 30.0 wt%, evaluation of appearance was X, evaluation of peel strength was X, evaluation of indentation property was X, and ease of measurement was ◎.

As shown in Table 3, when BPEF is used in combination with an anisotropic conductive film, the blending amount thereof is preferably 0.01 wt% or more and 5.0 wt% or less, more preferably 0.2 wt% or more and 1.0 wt% or less. When the blending amount of BPEF is increased, the easiness of measurement is improved, but bubbles are generated in the ACF at the time of pressing, and it is found that the peel strength and indentation property are deteriorated.

Claims (8)

A compound having a fluorene skeleton represented by the following formula (1) is used as a reference material, a sample solution containing an acrylic adhesive is separated by liquid chromatography, and an unreacted radically polymerizable compound is detected by an ultraviolet detector Determination of reaction rate.
[Chemical Formula 1]

Wherein R ₁ is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms, R ₂ is a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, And a hydroxyalkoxy group having 1 to 3 carbon atoms. The process according to claim 1, wherein the compound having a fluorene skeleton is at least one selected from the group consisting of bisphenoxyethanol fluorene (BPEF), bisphenol fluorene (BPFL), and biscresol fluorene (BCF) How to measure. The method according to claim 1 or 2, wherein the acrylic adhesive contains a compound having the fluorene skeleton. 4. The method according to claim 3, wherein the compounding amount of the compound having a fluorene skeleton is 0.01 wt% or more and 5.0 wt% or less. An acrylic adhesive containing a compound having a fluorene skeleton represented by the following formula (1), a radically polymerizable compound, and a reaction initiator.
(2)

Wherein R ₁ is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms, R ₂ is a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, And a hydroxyalkoxy group having 1 to 3 carbon atoms. 6. The composition according to claim 5, wherein the compound having a fluorene skeleton is at least one selected from the group consisting of bisphenol ethoxyl fluorene (BPEF), bisphenol fluorene (BPFL), and biscresol fluorene (BCF) glue. The acrylic adhesive according to claim 5 or 6, wherein the compounding amount of the fluorene backbone compound is 0.01 wt% or more and 5.0 wt% or less. An anisotropic conductive adhesive comprising conductive particles dispersed in the acrylic adhesive according to any one of claims 5 to 7.

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