KR102665572B1 - Curable resin compositions, cured bodies, electronic components and assembly parts - Google Patents

Abstract

In a predetermined adhesive test, the curable resin composition of the present invention has an adhesive strength of 6 kgf/cm ² or more at 80°C, an adhesive strength of 3.5 kgf/cm 2 or less at 120°C, and an adhesive strength of 3.5 kgf/cm ² or less at 25°C. The ratio of the volume at 120°C to the volume is 1.2 or less.

Description

Curable resin compositions, cured bodies, electronic components and assembly parts

The present invention relates to a curable resin composition, a cured body of the curable resin composition, and electronic components and assembled parts having the cured body of the curable resin composition.

Recently, there has been a demand for high integration and miniaturization in electronic components such as semiconductor chips. For example, there are cases where a plurality of thin semiconductor chips are bonded through an adhesive layer to form a stack of semiconductor chips. In addition, in modern times when mobile devices equipped with various display elements are becoming widespread, a method of miniaturizing display elements is to make the image display portion into a narrow frame (hereinafter also referred to as “narrow frame design”). In the design of narrow picture frames, a technology for bonding with an adhesive with a thin line width using a dispenser or the like is required.

In the adhesion of these small electronic components and the design of narrow picture frames, high adhesive strength is generally required, and as the adhesive, for example, as disclosed in Patent Document 1, a radically polymerizable compound, a moisture-curable urethane resin, and light are used. It is known that a light-moisture curable resin composition containing a radical polymerization initiator and a filler is used.

In addition, in the manufacture of the electronic components and image display units, it is desired that remanufacturing can be easily performed, and the adhesive may be required to have rejoining performance called reworkability. Therefore, adhesives may be required to have properties in which adhesive strength decreases under certain conditions such as heating.

For example, in Patent Document 2, a curable resin composition containing a urethane adhesive mixed with a mold release agent and a foaming agent is known as an adhesive whose adhesive strength decreases when heated. This adhesive reduces the adhesive force to the adherend by foaming the foaming agent by heating and transferring the mold release agent to the surface of the adhesive layer.

Japanese Patent Publication No. 2016-29186 Japanese Patent Publication No. 2003-286465

However, if the adhesive force is lowered by volume expansion using a foaming agent as in Patent Document 2, adhesive residue may increase, making it difficult to peel off the resin. Additionally, when attempting to transfer the release agent to the resin interface, the release agent may transfer over time even at low temperatures, deteriorating the reliability of the product.

In addition, electronic components such as semiconductor chips and display elements may be exposed to high temperatures of about 60 to 80 degrees Celsius during the assembly process or during use due to external heating or heat generation from the electronic components themselves during operation. , high adhesion is required even under such environments. On the other hand, when reworking electronic components under high temperature conditions, there is a problem that damage occurs in the electronic components, so it is preferable to rework them at as low a temperature as possible.

However, with conventional adhesives, it is difficult to sufficiently reduce the adhesive strength by low-temperature heating while maintaining high adhesive strength during the assembly process and under the usage environment, and the reworkability may be insufficient.

Therefore, the object of the present invention is to provide a curable resin composition that can exhibit high reworkability regardless of volume expansion even when heated at low temperatures while maintaining high adhesive strength in the assembly process of electronic components, under use environments, etc.

As a result of intensive study, the present inventors have found that the above-described problem can be solved by controlling the adhesive force at a predetermined temperature regardless of volume expansion, and have completed the present invention described below.

The present invention provides the following [1] to [11].

[1] In the following adhesion test, the adhesive force at 80°C is 6 kgf/cm ² or more, and the adhesive force at 120°C is 3.5 kgf/cm ² or less, and the volume at 120°C relative to the volume at 25°C A curable resin composition having a ratio of 1.2 or less.

＜Adhesion test＞

The curable resin composition is applied to an aluminum substrate so that the width is 1.0 ± 0.1 mm, the length is 25 ± 2 mm, and the thickness is 0.4 ± 0.1 mm, and then a glass plate is overlapped to cure the curable resin composition, and the aluminum substrate and The above glass plates are attached to produce a sample for an adhesion test. The prepared adhesion test sample was heated to 80°C by placing it in an 80°C atmosphere for 10 minutes, and then stretched in the shear direction at a speed of 5 mm/sec using a tensile tester in an 80°C atmosphere to ensure that the aluminum substrate and the glass plate were peeled off. The strength of the stain is measured to measure the adhesive force at 80°C. Additionally, the adhesive force at 120°C was measured in the same manner except that the heating temperature was changed to 120°C.

[2] In the following adhesion test, the adhesive force at 80°C is 6 kgf/cm ² or more, and the adhesive force at 100°C is 4 kgf/cm ² or less,

A curable resin composition wherein the ratio of the volume at 100°C to the volume at 25°C is 1.2 or less.

＜Adhesion test＞

The curable resin composition is applied to an aluminum substrate so that the width is 1.0 ± 0.1 mm, the length is 25 ± 2 mm, and the thickness is 0.4 ± 0.1 mm, and then a glass plate is overlapped to cure the curable resin composition, and the aluminum substrate and The above glass plates are attached to produce a sample for an adhesion test. The prepared adhesion test sample was heated to 80°C by placing it in an 80°C atmosphere for 10 minutes, and then stretched in the shear direction at a speed of 5 mm/sec using a tensile tester in an 80°C atmosphere to ensure that the aluminum substrate and the glass plate were peeled off. The strength of the stain is measured to measure the adhesive force at 80°C. Additionally, the adhesive force at 100°C was measured in the same manner except that the heating temperature was changed to 100°C.

[3] The above [1] wherein the ratio of the storage elastic modulus at 80°C to the storage elastic modulus at 120°C is 1.5 or more, and the storage elastic modulus at 25°C is 1.0×10 ⁵ Pa or more and 1.0×10 ⁸ Pa or less. Or the curable resin composition according to [2].

[4] The curable resin composition according to any one of [1] to [3] above, containing wax particles.

[5] The curable resin composition according to [4] above, wherein the ratio of the average particle diameter to the average primary particle diameter of the wax particles is 3 or less.

[6] The curable resin composition according to [4] or [5], wherein the wax particles have a melting point of 80°C or more and 110°C or less.

[7] The curable resin composition according to any one of [4] to [6] above, wherein the average particle diameter of the wax particles is 100 μm or less.

[8] A cured product of the curable resin composition according to any one of [1] to [7] above.

[9] An electronic component having the hardened body according to [8] above.

[10] It has a first substrate, a second substrate, and the cured body described in [8] above,

An assembled part in which at least a part of the first substrate is bonded to at least a part of the second substrate via the cured body.

[11] The assembled part according to [10], wherein the first substrate and the second substrate are each equipped with at least one electronic component.

According to the present invention, it is possible to provide a curable resin composition that maintains high adhesion during the assembly process of electronic components, under use environments, etc., and exhibits high reworkability regardless of volume expansion even when heated at low temperatures.

Figure 1 is a schematic diagram showing an adhesion test method, where Figure 1(a) is a top view and Figure 1(b) is a side view.

Hereinafter, the present invention will be described in detail.

The curable resin composition of the present invention has an adhesive force of 6 kgf/cm ² or more at 80°C and satisfies either the first or second requirements below.

First requirement: The adhesive force at 120°C is 3.5 kgf/cm ² or less, and the ratio of the volume at 120°C to the volume at 25°C is 1.2 or less.

Second requirement: Adhesion at 100°C is 4 kgf/cm ² or less, and the ratio of the volume at 100°C to the volume at 25°C is 1.2 or less.

The curable resin composition of the present invention may satisfy either the first requirement or the second requirement, but preferably satisfies both the first and second requirements.

The curable resin composition of the present invention has an adhesive force of 6 kgf/cm ² or more at 80° C., so that it can adhere adherends such as electronic components and substrates with high adhesive force during assembly processes and under use environments. In addition, the adhesive force at 120°C or 100°C is 3.5 kgf/cm ² or less or 4 kgf/cm ² or less, making it possible to easily peel off the adherend bonded by the curable resin composition even when heated to a relatively low temperature. This results in excellent reworkability.

On the other hand, if the adhesive force at 80°C is less than 6 kgf/cm ² , or the adhesive force at 100°C is higher than 4.0 kgf/cm ² , and the adhesive force at 120°C is higher than 3.5 kgf/cm ² , Neither workability nor adhesion performance improves.

The adhesive force at 80°C is preferably 7 kgf/cm ² or more, and more preferably 8 kgf/cm ² or more from the viewpoint of further improving adhesive performance. In addition, the higher the adhesive strength at 80°C, the better in order to improve the adhesive performance, but for practical purposes, it is 25 kgf/cm or less, preferably 20 kgf/cm ² or less.

The adhesive strength at 120°C is preferably 3.0 kgf/cm ² or less, more preferably 2.5 kgf/cm ² or less from the viewpoint of further improving reworkability. In addition, the lower the adhesive strength at 120°C, the better in order to improve reworkability, but for practical purposes, it is 0.1 kgf/cm ² or more, preferably 0.4 kgf/cm ² or more.

Additionally, the adhesive strength at 100°C is preferably 4.0 kgf/cm ² or less, more preferably 3.0 kgf/cm ² or less from the viewpoint of further improving reworkability. In addition, the lower the adhesive strength at 100°C, the better in order to improve reworkability, but for practical purposes, it is 0.1 kgf/cm or more, preferably 0.5 kgf/cm or more.

Additionally, in the curable resin composition, volume expansion occurs due to heating when the ratio of the volume at 120°C or 100°C to the volume at 25°C is greater than 1.2. Therefore, adhesive residue may increase, making it difficult to peel off the resin.

Moreover, it is preferable that the curable resin composition exhibits little dimensional change due to heating. Therefore, the ratio of the volume at 120°C to the volume at 25°C is preferably 1 or close to 1. Specifically, 1.1 or less is preferable, and 1.05 or less is more preferable. Moreover, 0.9 or more is preferable, and 0.95 or more is more preferable.

From the same viewpoint, the curable resin composition preferably has a ratio of the volume at 100°C to the volume at 25°C of 1 or close to 1. Specifically, 1.1 or less is preferable, and 1.05 or less is more preferable. Moreover, 0.9 or more is preferable, and 0.95 or more is more preferable.

(Adhesion test)

In the present invention, the adhesive strength at 80°C, 100°C, and 120°C is measured by the following adhesive test.

As shown in Figures 1 (a) and (b), the curable resin composition 10 is applied to the aluminum substrate 11 so as to have a width of 1.0 ± 0.1 mm, a length of 25 ± 2 mm, and a thickness of 0.4 ± 0.1 mm. After that, the glass plates 12 are overlapped to cure the curable resin composition, and the aluminum substrate 11 and the glass plate 12 are attached to produce a sample 13 for an adhesion test. The prepared adhesion test sample 13 was placed in an atmosphere of 80°C for 10 minutes, heated to 80°C, and stretched at a speed of 5 mm/sec in the shear direction (S) using a tensile tester under that atmosphere to form an aluminum substrate. The strength when (11) and the glass plate (12) are peeled off is measured, and the adhesive force at 80°C is measured. Additionally, the adhesive strength at 100°C and 120°C was measured in the same manner except that the temperature under the atmosphere (i.e., heating temperature) was changed to 100°C and 120°C, respectively.

Here, the curing conditions of the curable resin composition are the same as the curing conditions under which the curable resin composition of the present invention is used as an adhesive, and it is preferable to set the following conditions according to the curing mechanism.

In the case of the photocurable resin composition, it is applied to the aluminum substrate 11 using a dispensing device to a width of 1.0 ± 0.1 mm, a length of 25 ± 2 mm, and a thickness of 0.4 ± 0.1 mm, and a glass plate ( 12) is attached and photocured by irradiation with a mercury lamp at 3000 mJ/cm ² to prepare a sample 13 for an adhesive test.

In the case of a moisture-curable resin composition, it is applied to the aluminum substrate 11 to a width of 1.0 ± 0.1 mm, a length of 25 ± 2 mm, and a thickness of 0.4 ± 0.1 mm using a dispensing device, and a glass plate is placed on the aluminum substrate 11. (12) is attached and left to stand at 25°C and 50RH% for 3 days to moisture cure to obtain a sample (13) for evaluation of adhesion.

In the case of the light-moisture curable resin composition, first, using a dispensing device, it is applied to the aluminum substrate 11 to a width of 1.0 ± 0.1 mm, a length of 25 ± 2 mm, and a thickness of 0.4 ± 0.1 mm, and 3000 mJ is applied using a mercury lamp. /cm ² It is photocured by irradiation. After that, the glass plate 12 is attached to the aluminum substrate 11, given a weight of 100 g, left at 25°C and 50RH% for 3 days to moisture cure, and a sample 13 for adhesion evaluation is obtained.

In the case of a thermosetting resin composition, it is applied to the aluminum substrate 11 using a dispensing device to a width of 1.0 ± 0.1 mm, a length of 25 ± 2 mm, and a thickness of 0.4 ± 0.1 mm, and a glass plate ( 12) is attached and heated at 90°C for 2 hours to create a sample 13 for adhesion testing.

In addition, in this test, aluminum alloy "AL-6063" is used as the aluminum substrate. Additionally, a glass plate that has been cleaned ultrasonically for 5 minutes is used.

The curable resin composition of the present invention has a storage elastic modulus ratio at 80°C to the storage elastic modulus at 120°C (hereinafter simply referred to as “storage elastic modulus ratio”) of 1.5 or more, and a storage elastic modulus at 25°C. It is preferable that the elastic modulus is 1.0×10 ⁵ Pa or more and 1.0×10 ⁸ Pa or less. In the present invention, by setting the storage elastic modulus at 25°C to the above range and then setting the storage elastic modulus ratio to 1.5 or more, it becomes easy to adjust the adhesive strength at 80°C, 100°C, and 120°C within the above range.

In the present invention, the storage elastic modulus at 25°C, 80°C, and 120°C is measured using the following measurement method.

A cured body is obtained by pouring the curable resin composition into a Teflon (registered trademark) mold with a width of 3 mm, a length of 30 mm, and a thickness of 1 mm, and curing the mold. In the case of light-moisture curing, the curing of the curable resin composition is carried out by photocuring it by irradiating it with 3000 mJ/cm ² with a mercury lamp, and then moisture curing it by leaving it in an environment of 23°C and 50RH% for 3 days. In addition, in the case of photocurability, the moisture curing step is omitted, and in the case of moisture curability, the photocuring step is omitted, and the same procedure is performed as above. In addition, in the case of thermosetting, curing is performed by heating at 90°C for 2 hours.

Using the obtained cured body, dynamic viscoelasticity is measured in the range of 40 to 150°C using a dynamic viscoelasticity measuring device (product name "DVA-200", manufactured by IT Measurement Control), and the storage elastic modulus at each temperature is determined. Additionally, the measurement conditions are that the strain mode is tension, the set strain is 1%, the measurement frequency is 1 Hz, and the temperature increase rate is 5°C/min.

From the viewpoint of increasing the adhesive strength at 80°C and lowering the adhesive strength at 100°C or 120°C, the storage modulus ratio is preferably 1.7 or more, and more preferably 3.0 or more. Moreover, the upper limit of the storage elastic modulus ratio is not particularly limited, but is, for example, 15, preferably 10.

The storage elastic modulus at 25°C is more preferably 5.0×10 ⁵ Pa or more, and is further more preferably 3.0×10 ⁶ Pa or more in order to easily adjust the adhesive strength at 80°C, 100°C, and 120°C to the desired range. desirable. Moreover, 5.0×10 ⁷ Pa or less is more preferable, and 2.0×10 ⁷ Pa or less is further preferable.

[Curable Resin]

The curable resin composition of the present invention may be any of thermosetting, photocuring, and moisture curing, but it is preferable to have at least one of photocuring and moisture curing. If it has photocurability or moisture curability, the curable resin composition can be cured without heating. Therefore, when curing the curable resin composition, it is possible to prevent the adhesive portion or the electronic components around the adhesive portion from being damaged by heating. In addition, the wax particles described later are not heated and melted during curing, but can exist in the form of particles in the cured product, making it easier to achieve good rework properties.

Moreover, among moisture curing properties and photocuring properties, moisture curing properties are preferable from the viewpoint of adhesive strength, and photocuring properties are preferable from the viewpoint of curing speed. In addition, from the viewpoint of requiring adhesion and curing speed, the curable resin composition preferably has both photocurability and moisture curability, that is, light and moisture curability. If the curable resin composition has light-moisture curability, for example, it is first photo-cured to provide relatively low adhesive strength, and then left in the air to cure with moisture to form a cured product with sufficient adhesive strength. It becomes possible.

The curable resin composition of the present invention contains a curable resin, and the type of curable resin used is selected depending on the curing characteristics of the curable resin composition. The curable resin may be, specifically, any of moisture-curable resin, thermosetting resin, and photo-curable resin, but is preferably at least one selected from moisture-curable resin and photo-curable resin, and the moisture-curable resin and the photo-curable resin It is more preferable to contain both.

The content of the curable resin is preferably 50 parts by mass or more, more preferably 55 parts by mass or more, and still more preferably 60 parts by mass or more, with respect to 100 parts by mass of the curable resin composition. Moreover, the content of the curable resin is preferably 97 parts by mass or less, more preferably 90 parts by mass or less, and still more preferably 75 parts by mass or less, with respect to 100 parts by mass of the curable resin composition. By keeping the content of the curable resin within these ranges, it becomes easy to adjust the storage elastic modulus at 25°C and the storage elastic modulus ratio to the above desired range.

(moisture curable resin)

Examples of the moisture-curable resin include moisture-curable urethane resin, hydrolyzable silyl group-containing resin, moisture-curable cyanoacrylate resin, and among them, moisture-curable urethane resin is preferable.

Moisture-curable urethane resin has a urethane bond and an isocyanate group, and the isocyanate group in the molecule reacts with moisture in the air or in the adherend to cure. The moisture-curable urethane resin may have only one isocyanate group per molecule, or may have two or more isocyanate groups. Among these, it is preferable to have isocyanate groups at both ends of the main chain of the molecule.

Moisture-curable urethane resin can be obtained by reacting a polyol compound having two or more hydroxyl groups per molecule with a polyisocyanate compound having two or more isocyanate groups per molecule.

The reaction between the polyol compound and the polyisocyanate compound is usually carried out in the range of [NCO]/[OH]=2.0 to 2.5 in a molar ratio of the hydroxyl group (OH) in the polyol compound and the isocyanate group (NCO) in the polyisocyanate compound.

As the polyol compound that serves as the raw material for the moisture-curable urethane resin, known polyol compounds commonly used in the production of polyurethane can be used, such as polyester polyol, polyether polyol, polyalkylene polyol, and polycarbonate polyol. etc. can be mentioned. These polyol compounds may be used individually, or may be used in combination of two or more types.

Examples of the polyester polyol include polyester polyol obtained by reaction of polyhydric carboxylic acid and polyol, poly-ε-caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone, and the like.

Examples of the polyhydric carboxylic acids that serve as raw materials for polyester polyol include terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and aqueous acid. Examples include beric acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid.

Polyols that serve as raw materials for polyester polyol include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, and 1,6-hexanediol. , diethylene glycol, cyclohexanediol, etc.

Examples of polyether polyols include ethylene glycol, propylene glycol, ring-opened polymers of tetrahydrofuran, ring-opened polymers of 3-methyltetrahydrofuran, random or block copolymers of these or their derivatives, and bisphenol-type polyether polyols. Polyoxyalkylene modified products, etc. can be mentioned.

Here, the bisphenol-type polyoxyalkylene modified product is obtained by adding an alkylene oxide (e.g., ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, etc.) to the active hydrogen portion of the bisphenol-type molecular skeleton. It is a polyether polyol obtained through reaction. The polyether polyol may be a random copolymer or a block copolymer. The bisphenol-type polyoxyalkylene modified product preferably has one or two or more types of alkylene oxides added to both ends of the bisphenol-type molecular skeleton.

The bisphenol type is not particularly limited and includes type A, type F, and type S, and bisphenol type A is preferred.

Examples of polyalkylene polyol include polybutadiene polyol, hydrogenated polybutadiene polyol, and hydrogenated polyisoprene polyol.

Examples of polycarbonate polyol include polyhexamethylene carbonate polyol, polycyclohexanedimethylene carbonate polyol, and the like.

As polyisocyanate compounds that serve as raw materials for moisture-curable urethane resins, aromatic polyisocyanate compounds and aliphatic polyisocyanate compounds are suitably used.

Examples of aromatic polyisocyanate compounds include diphenylmethane diisocyanate, liquid modified products of diphenylmethane diisocyanate, polymeric MDI, tolylene diisocyanate, and naphthalene-1,5-diisocyanate.

Examples of aliphatic polyisocyanate compounds include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate, transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, and hydrogenated xylene diisocyanate. Isocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, bis(isocyanate methyl)cyclohexane, dicyclohexylmethane diisocyanate, etc. are mentioned.

Among the polyisocyanate compounds, diphenylmethane diisocyanate and its modified products are preferable because of low vapor pressure and toxicity, and ease of handling.

The polyisocyanate compound may be used individually, or may be used in combination of two or more types.

The moisture-curable urethane resin is preferably obtained using a polyol compound having a structure represented by the following formula (1). By using a polyol compound having a structure represented by the following formula (1), a curable resin composition with excellent adhesiveness and a cured product that is flexible and has good extensibility can be obtained, and is compatible with the radical polymerizable compound described later. This becomes excellent. In addition, it becomes easy to adjust the storage elastic modulus ratio and the storage elastic modulus at 25°C to within the above desired range.

Among them, it is preferable to use a polyether polyol composed of propylene glycol, a ring-opening polymerization compound of a tetrahydrofuran (THF) compound, or a ring-opening polymerization compound of a tetrahydrofuran compound having a substituent such as a methyl group.

In formula (1), R represents a hydrogen atom, a methyl group, or an ethyl group, l is an integer of 0 to 5, m is an integer of 1 to 500, and n is an integer of 1 to 10. l is preferably 0 to 4, m is preferably 50 to 200, and n is preferably 1 to 5. Additionally, the case where l is 0 means that the carbon bonded to R is directly bonded to oxygen.

The hydrolyzable silyl group-containing resin cures when the hydrolyzable silyl group in the molecule reacts with moisture in the air or in the adherend.

The hydrolyzable silyl group-containing resin may have only one hydrolyzable silyl group in one molecule, or may have two or more hydrolyzable silyl groups. Among them, those having hydrolyzable silyl groups at both ends of the main chain of the molecule are preferable.

The hydrolyzable silyl group is represented by the following formula (2).

In formula (2), R ¹ is each independently an optionally substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or -OSiR ² ₃ (R ² is each independently a hydrocarbon group having 1 to 20 carbon atoms). Moreover, in formula (2), X is each independently a hydroxy group or a hydrolyzable group. Additionally, in formula (2), a is an integer of 1 to 3.

The hydrolyzable group is not particularly limited and includes, for example, a hydrogen atom, a halogen atom, an alkoxy group, an alkenyloxy group, an aryloxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, and an amino oxy group. Examples include period, mercapto period, etc. Among them, halogen atoms, alkoxy groups, alkenyloxy groups, and acyloxy groups are preferred because of their high activity. Moreover, since the hydrolyzability is mild and it is easy to handle, alkoxy groups such as methoxy group and ethoxy group are more preferable, and methoxy group and ethoxy group are more preferable. Also, from the viewpoint of safety, ethoxy groups and isopropenoxy groups, where the compounds released by the reaction are ethanol and acetone, respectively, are preferable.

The hydroxy group or the hydrolyzable group can be bonded to one silicon atom in the range of 1 to 3. When two or more of the hydroxy groups or the hydrolyzable groups are bonded to one silicon atom, these groups may be the same or different.

From the viewpoint of curability, a in the formula (2) is preferably 2 or 3, and is particularly preferably 3. Moreover, from the viewpoint of storage stability, a is preferably 2.

Additionally, R ¹ in the formula (2) above includes, for example, an alkyl group such as a methyl group or an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, or a trimethylsiloxy group. A chloromethyl group, a methoxymethyl group, etc. are mentioned. Among them, a methyl group is preferable.

Examples of the hydrolyzable silyl group include methyldimethoxysilyl group, trimethoxysilyl group, triethoxysilyl group, tris(2-propenyloxy)silyl group, triacetoxysilyl group, (chloromethyl) Dimethoxysilyl group, (chloromethyl)diethoxysilyl group, (dichloromethyl)dimethoxysilyl group, (1-chloroethyl)dimethoxysilyl group, (1-chloropropyl)dimethoxysilyl group, (methoxymethyl) Dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, (ethoxymethyl)dimethoxysilyl group, (1-methoxyethyl)dimethoxysilyl group, (aminomethyl)dimethoxysilyl group, (N,N -dimethylaminomethyl)dimethoxysilyl group, (N,N-diethylaminomethyl)dimethoxysilyl group, (N,N-diethylaminomethyl)diethoxysilyl group, (N-(2-aminoethyl)amino Examples include methyl)dimethoxysilyl group, (acetoxymethyl)dimethoxysilyl group, and (acetoxymethyl)diethoxysilyl group.

Examples of the hydrolyzable silyl group-containing resin include (meth)acrylic resin containing a hydrolyzable silyl group, an organic polymer having a hydrolyzable silyl group at the end of the molecular chain or at the terminal portion of the molecular chain, and a polyurethane resin containing a hydrolyzable silyl group. I can hear it.

The hydrolyzable silyl group-containing (meth)acrylic resin preferably has repeating structural units derived from hydrolyzable silyl group-containing (meth)acrylic acid ester and (meth)acrylic acid alkyl ester in the main chain. In addition, in this specification, “(meth)acrylic acid” means acrylic acid or methacrylic acid, “(meth)acrylate” means acrylate or methacrylate, and the same applies to other similar terms.

Examples of hydrolyzable silyl group-containing (meth)acrylic acid esters include 3-(meth)acrylic acid 3-(trimethoxysilyl)propyl (meth)acrylic acid, 3-(triethoxysilyl)propyl (meth)acrylic acid, and 3-(meth)acrylic acid. (methyldimethoxysilyl)propyl, 2-(trimethoxysilyl)ethyl (meth)acrylic acid, 2-(triethoxysilyl)ethyl (meth)acrylic acid, 2-(methyldimethoxysilyl)ethyl (meth)acrylic acid, (meth)acrylic acid trimethoxysilylmethyl, (meth)acrylic acid triethoxysilylmethyl, (meth)acrylic acid (methyldimethoxysilyl)methyl, etc. are mentioned.

Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylate. ) Isobutyl acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n- (meth)acrylic acid. Octyl, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, stearyl (meth)acrylate, etc.

Specific examples of methods for producing a (meth)acrylic resin containing a hydrolyzable silyl group include, for example, the method for synthesizing a (meth)acrylic acid ester-based polymer containing a hydrolysable silicon group described in International Publication No. 2016/035718, etc. can be mentioned.

The organic polymer having a hydrolyzable silyl group at the molecular chain terminal or molecular chain terminal portion has a hydrolyzable silyl group at at least one of the terminal of the main chain and the terminal of the side chain.

The skeletal structure of the main chain is not particularly limited, and examples include saturated hydrocarbon-based polymers, polyoxyalkylene-based polymers, and (meth)acrylic acid ester-based polymers.

Examples of the polyoxyalkylene polymer include polyoxyethylene structure, polyoxypropylene structure, polyoxybutylene structure, polyoxytetramethylene structure, polyoxyethylene-polyoxypropylene copolymer structure, and polyoxypropylene-polymer structure. and polymers having an oxybutylene copolymer structure.

As a method for producing an organic polymer having a hydrolyzable silyl group at the molecular chain terminal or molecular chain terminal portion, specifically, for example, the molecular chain terminal or molecular chain terminal portion described in International Publication No. 2016/035718. A method of synthesizing an organic polymer having a crosslinkable silyl group can be cited. In addition, as another method for producing an organic polymer having a hydrolyzable silyl group at the molecular chain terminal or molecular chain terminal portion, for example, a polyoxyalkylene-based polymer containing a reactive silicon group described in International Publication No. 2012/117902. Synthesis methods, etc. can be mentioned.

As a method for producing the hydrolyzable silyl group-containing polyurethane resin, for example, when producing a polyurethane resin by reacting a polyol compound and a polyisocyanate compound, a silyl group-containing compound such as a silane coupling agent is further reacted. Methods, etc. may be mentioned. Specifically, for example, the method for synthesizing a urethane oligomer having a hydrolyzable silyl group described in Japanese Patent Application Laid-Open No. 2017-48345.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxy-ethoxy)silane, and β-(3,4-epoxycyclohexyl)-ethyltrimethoxy. Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrime Toxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrime Toxysilane, γ-aminopropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, etc. are mentioned. Among them, γ-mercaptopropyltrimethoxysilane, 3-isocyanate propyltrimethoxysilane, and 3-isocyanate propyltriethoxysilane are preferable. These silane coupling agents may be used individually, or two or more types may be used in combination.

Additionally, the moisture-curable resin may have a radically polymerizable functional group. As a radically polymerizable functional group that the moisture-curable resin may have, a group having an unsaturated double bond is preferable, and a (meth)acryloyl group is more preferable, especially from the viewpoint of reactivity. In addition, the moisture-curable resin having a radically polymerizable functional group is not included in the radically polymerizable compounds described later and is handled as a moisture-curable resin.

The weight average molecular weight of the moisture-curable resin is not particularly limited, but the preferred lower limit is 800 and the preferred upper limit is 10,000. When the weight average molecular weight of the moisture-curable resin is within this range, the resulting curable resin composition has a crosslinking density that does not become too high during curing, has better flexibility, and has better applicability. The more preferable lower limit of the weight average molecular weight of the moisture-curable resin is 2000, the more preferable upper limit is 8000, the more preferable lower limit is 2500, and the more preferable upper limit is 6000. In this specification, the weight average molecular weight is a value determined by gel permeation chromatography (GPC) and converted to polystyrene. As a column for measuring the weight average molecular weight in terms of polystyrene by GPC, Shodex LF-804 (manufactured by Showa Denko) can be used. Additionally, examples of solvents used in GPC include tetrahydrofuran.

(Photocurable resin)

Examples of the photocurable resin of the present invention include radically polymerizable compounds. It is preferable to use the radically polymerizable compound in combination with the moisture-curable resin, and by using it in combination, the curable resin composition becomes photo-moisture-curable.

The radically polymerizable compound may be a radically polymerizable compound having photopolymerizability, and is not particularly limited as long as it is a compound having a radically polymerizable functional group in the molecule. Among them, compounds having an unsaturated double bond as a radically polymerizable functional group are suitable, and compounds having a (meth)acryloyl group (hereinafter also referred to as “(meth)acrylic compound”) are particularly suitable from the viewpoint of reactivity.

Examples of the (meth)acrylic compounds include (meth)acrylic acid ester compounds, epoxy (meth)acrylate, and urethane (meth)acrylate. In addition, urethane (meth)acrylate does not have a residual isocyanate group.

The (meth)acrylic acid ester compound may be monofunctional, difunctional, or trifunctional or higher.

Among the (meth)acrylic acid ester compounds, monofunctional ones include, for example, phthalimide acrylates such as N-acryloyloxyethylhexahydrophthalimide, various imide (meth)acrylates, and methyl (meth)acrylates. ) Acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-octyl (meth) Acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate ) Acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethylcarbitol (meth)acrylate , tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate Ethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-(meth)acryloyloxyethyl-2-hydroxy Propyl phthalate, glycidyl (meth)acrylate, 2-(meth)acryloyloxyethyl phosphate, etc. can be mentioned.

Among the (meth)acrylic acid ester compounds, bifunctional ones include, for example, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. ) Acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth) Acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate , tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethylene oxide added bisphenol A di(meth)acrylate, propylene oxide added bisphenol A di(meth)acrylate, ethylene oxide. Addition bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide modified isocyanuric acid di(meth)acrylate, 2-hyde. Roxy-3-(meth)acryloyloxypropyl(meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone Dioldi(meth)acrylate, polybutadienedioldi(meth)acrylate, etc. can be mentioned.

In addition, among the (meth)acrylic acid ester compounds, those having three or more functions include, for example, trimethylolpropane tri(meth)acrylate, ethylene oxide added trimethylolpropane tri(meth)acrylate, and propylene oxide added trimethylolpropane. Tri(meth)acrylate, caprolactone modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethylene oxide added isocyanuric acid tri(meth)acrylate, glycerin tri(meth)acrylate. Acrylate, propylene oxide added glycerin tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythate. Litol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. can be mentioned.

Examples of the epoxy (meth)acrylate include those reacted with an epoxy compound and (meth)acrylic acid. Here, the reaction between the epoxy compound and (meth)acrylic acid may be performed in the presence of a basic catalyst according to a conventional method. Epoxy (meth)acrylate may be monofunctional or polyfunctional, such as difunctional.

Examples of epoxy compounds that serve as raw materials for synthesizing the epoxy (meth)acrylate include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, and 2,2'-diallyl bisphenol A-type. Epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type. Epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, orthocresol novolak type epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthalenephenol novolak type epoxy resin, Cydylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified epoxy resin, glycidyl ester compound, bisphenol A type episulfide resin, etc. are mentioned.

Among the above epoxy (meth)acrylates, commercially available ones include, for example, EBECRYL 860, EBECRYL 3200, EBECRYL 3201, EBECRYL 3412, EBECRYL 3600, EBECRYL 3700, EBECRYL 3701, EBECRYL 3702, EBECRYL 3703, EBECRYL 3800, EBECRYL 6040 , EBECRYL RDX63182 (all manufactured by Daicel Allnex), EA-1010, EA-1020, EA-5323, EA-5520, EACHD, EMA-1020 (all manufactured by Shinnakamura Chemical Industries), epoxy ester M-600A, epoxy Ester 40EM, Epoxyester 70PA, Epoxyester 200PA, Epoxyester 80MFA, Epoxyester 3002M, Epoxyester 3002A, Epoxyester 1600A, Epoxyester 3000M, Epoxyester 3000A, Epoxyester 200EA, Ster 400EA (all manufactured by Kyoeisha Chemical) , Denacol acrylate DA-141, Denacol acrylate DA-314, and Denacol acrylate DA-911 (all manufactured by Nagase Chemtex).

Urethane (meth)acrylate can be used, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group. Here, in the reaction between the isocyanate compound and the (meth)acrylic acid derivative, a catalytic amount of a tin-based compound or the like may be used as a catalyst. Urethane (meth)acrylate may be monofunctional or polyfunctional, such as difunctional.

Isocyanate compounds used to obtain urethane (meth)acrylate include, for example, isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate. , diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, trizyne diisocyanate, xylylene diisocyanate (XDI), hydrogen Added

Moreover, as the isocyanate compound, a chain-extended isocyanate compound obtained by reaction of a polyol and an excess isocyanate compound can also be used. Here, examples of polyols include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

Examples of the (meth)acrylic acid derivative having the hydroxyl group include mono ( Meth)acrylates, mono(meth)acrylates or di(meth)acrylates of trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerin, and epoxy(meth)acrylates such as bisphenol A type epoxy(meth)acrylates. ) Acrylates, etc. can be mentioned.

Among the above urethane (meth)acrylates, commercially available ones include, for example, M-1100, M-1200, M-1210, M-1600 (all manufactured by Toa Synthetics), EBECRYL 230, EBECRYL 270, EBECRYL 4858, and EBECRYL. 8402, EBECRYL 8411, EBECRYL 8412, EBECRYL 8413, EBECRYL 8804, EBECRYL 8803, EBECRYL 8807, EBECRYL 9260, EBECRYL 1290, EBECRYL 5129, EBECRYL 4842, EBECRYL 2 10, EBECRYL 4827, EBECRYL 6700, EBECRYL 220, EBECRYL 2220, KRM7735, KRM -8295 (all manufactured by Daicel and Allnex), Art Resin UN-9000H, Art Resin UN-9000A, Art Resin UN-7100, Art Resin UN-1255, Art Resin UN-330, Art Resin UN-3320 HB, Art Resin Resin UN-1200 TPK, Art Resin SH-500B (all manufactured by Negami Industries), U-2HA, U-2PHA, U-3HA, U-4HA, U-6H, U-6LPA, U-6HA, U-10H , U-15HA, U-122A, U-122P, U-108, U-108A, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4100, UA -4000, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, UA-W2A (all manufactured by Shinnakamura Chemical Industries), AI-600, AH-600, AT-600, UA-101I , UA-101T, UA-306H, UA-306I, UA-306T (all manufactured by Kyoeisha Chemical), etc.

As the radically polymerizable compound, other radically polymerizable compounds other than those described above can also be appropriately used. Other radically polymerizable compounds include, for example, N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-hydroxyethyl(meth)acrylamide, and N,N-diethyl. (meth)acrylamide compounds such as (meth)acrylamide, N-isopropyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, styrene, α-methylstyrene, N-vinyl-2- Vinyl compounds such as pyrrolidone and N-vinyl-ε-caprolactam, etc. can be mentioned.

In the curable resin composition, when the content of the radically polymerizable compound is used in combination with the moisture-curable resin, the mass ratio (radically polymerizable compound/moisture-curable resin) to the content of the moisture-curable resin is preferably 1/9 or more. 9 or less, more preferably 3/7 or more and 7/3 or less, and further preferably 1/2 or more and 2 or less. By setting this mass ratio, the adhesive strength of the curable resin composition can be increased while improving the curing speed.

The radically polymerizable compound preferably contains a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound from the viewpoint of adjusting curability. By containing the monofunctional radically polymerizable compound and the polyfunctional radically polymerizable compound, the resulting curable resin composition has better curability and tack properties. Moreover, the polyfunctional radically polymerizable compound is preferably bi- or tri-functional, and more preferably bi-functional.

When the radically polymerizable compound contains a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound, the content of the polyfunctional radically polymerizable compound is 100 in total of the monofunctional radically polymerizable compound and the polyfunctional radically polymerizable compound. With respect to parts by mass, it is preferably 2 parts by mass or more, and preferably 45 parts by mass or less. When the content of the polyfunctional radically polymerizable compound is within this range, the resulting curable resin composition becomes more excellent in curability and tackiness. Moreover, the content of the polyfunctional radically polymerizable compound is more preferably 20 parts by mass or more, and even more preferably 40 parts by mass or less.

In the present invention, it is preferable to use at least one type selected from epoxy (meth)acrylate and urethane (meth)acrylate as the radically polymerizable compound.

Moreover, it is preferable to use at least one type selected from epoxy (meth)acrylate and urethane (meth)acrylate in combination with a (meth)acrylic acid ester compound. By using these two types or more compounds together, it becomes easy to adjust the storage elastic modulus and storage elastic modulus ratio at 25°C within the above range.

In addition, from the viewpoint of making it easy to adjust the storage elastic modulus and storage elastic modulus ratio at 25°C within the above range, the content of the (meth)acrylic acid ester compound is calculated from epoxy (meth)acrylate and urethane (meth)acrylate. The content ratio (mass ratio) of at least one selected type is preferably 0.2 or more. The mass ratio is more preferably 0.35 or more, and more preferably 0.4 or more. Moreover, the mass ratio is preferably 0.8 or less, more preferably 0.7 or less, and still more preferably 0.6 or less.

Moreover, at least one type selected from epoxy (meth)acrylate and urethane (meth)acrylate may be monofunctional or may be bifunctional or more polyfunctional, but it is more preferable that it is polyfunctional. On the other hand, the (meth)acrylic acid ester compound is preferably monofunctional. Moreover, urethane (meth)acrylate is preferable as at least 1 type selected from epoxy (meth)acrylate and urethane (meth)acrylate.

(thermosetting resin)

The thermosetting resin is not particularly limited, but when the curable resin composition contains wax particles described later, it is preferably cured at a temperature below the melting point of the wax particles. By using a thermosetting resin that hardens at a temperature below the melting point of the wax particles, the wax particles do not melt or aggregate during curing, and the average particle diameter and average particle diameter/average primary particle diameter of the wax particles in the cured body are as described later. It becomes the same as the curable resin composition. Additionally, by lowering the curing temperature of the thermosetting resin, the electronic components at or around the adhesive portion are prevented from being damaged by heating. In addition, the thermosetting resin may be used in combination with another curing resin, for example, may be used in combination with the photocurable resin described above.

Specifically, the thermosetting resin may be used, for example, one that is cured by heating to a temperature of 60°C or more and less than 120°C, more preferably less than 100°C.

Specific examples of thermosetting resins include epoxy resins, phenol resins, urethane resins, unsaturated polyester resins, urea resins, and melamine resins. In addition, when the curable resin composition contains a thermosetting resin, it may contain a curing catalyst, a curing accelerator, etc. as appropriate so that the thermosetting resin can be cured at the above temperature.

(wax particles)

The curable resin composition of the present invention preferably contains wax particles. Wax particles are wax that exists in particle form in a curable resin composition. By melting by heating, the wax particles soften the curable resin composition, thereby making it easier to adjust the storage modulus within the desired range. In addition, melting the wax reduces the adhesive strength of the curable resin composition, but since the contact area with the curable resin increases when the wax is in particle form, the adhesive strength becomes more likely to be reduced. Therefore, by containing wax particles, the curable resin composition makes the adhesive strength at 100°C or 120°C sufficiently low and becomes easy to adjust to within the above range.

In addition, in this specification, “wax” means an organic substance that is solid at 23°C and becomes liquid when heated.

The melting point of the wax particles is preferably 80°C or higher and 110°C or lower. By keeping the melting point of the wax particles within the above range, it becomes easy to increase the adhesive force at 80°C and lower the adhesive force at 100°C or 120°C. From the viewpoint of further increasing the adhesive strength at 80°C, the melting point of the wax particles is more preferably 82°C or higher. Moreover, from the viewpoint of lowering the adhesive force at 100°C or 120°C, the melting point of the wax particles is more preferably 105°C or lower, and still more preferably 100°C or lower.

In addition, the melting point of the wax particles is set to the temperature that shows the peak top of endotherm in the graph obtained by differential scanning calorimetry. In addition, differential scanning calorimetry is performed using a differential scanning calorimetry device (DSC Q100, manufactured by TA Instruments). The measurement conditions are as follows.

Plate: Aluminum Hermetic

Atmosphere: Nitrogen (40mL/min)

Temperature increase rate: 10℃/min

Sample amount: 10mg

The average particle diameter of the wax particles is preferably 100 μm or less, more preferably 50 μm or less, further preferably 25 μm or less, and particularly preferably 10 μm or less. The smaller the average particle diameter of the wax particles, the larger the contact area with the curable resin, and the easier it is to lower the adhesive force at 100°C or 120°C. Additionally, the lower limit of the average particle diameter of the wax particles is not particularly limited, but is practically 0.1 μm, preferably 0.5 μm.

In addition, the ratio of the average particle diameter to the average primary particle diameter of the wax particles (hereinafter also referred to as “average particle diameter/average primary particle diameter”) indicates the degree of aggregation of the wax particles, and those that do not aggregate at all are the average particles. The elapsed average primary particle diameters coincide, and the average particle diameter/average primary particle diameter becomes 1. In the present invention, wax particles that do not aggregate tend to reduce adhesive strength when heated to 100°C or 120°C. Therefore, from the viewpoint of lowering the adhesion at 100°C and 120°C, the average particle diameter/average primary particle diameter is preferably as low as possible, preferably 3 or less, more preferably 2 or less, and even more preferably 1.5 or less. do. Additionally, the lower limit of average particle diameter/average primary particle diameter is 1.

Additionally, the average particle diameter of the wax particles contained in the curable resin composition can be obtained by observing the curable resin composition with a scanning electron microscope, measuring the particle diameters of 50 randomly selected particles, and calculating the average value. In addition, wax particles may consist of a plurality of particles aggregated to form one particle. In that case, the particle size of each particle means the particle size of the aggregate (secondary particle size). Additionally, the particle diameter measures the maximum diameter of each particle.

Additionally, when measuring the particle diameter of each wax particle, the primary particle diameter of the measured particles is also measured, and the average value is taken as the average primary particle diameter to calculate average particle diameter/average primary particle diameter. Additionally, the primary particle diameter of each particle is the same as the particle diameter for non-agglomerated particles, and for agglomerated particles, the average value of the particle diameters of all observed primary particles is taken as the primary particle diameter of that particle.

Additionally, increasing the content of wax particles per unit area in the curable resin composition makes it easier to reduce the adhesive force by heating. Therefore, by making the thickness of the curable resin composition as large as possible to maintain adhesiveness, it becomes easier to reduce the adhesive force.

Therefore, in order to maintain the thickness of the curable resin composition above a certain level during bonding, it is preferable to photocure it as a pretreatment. That is, in the case of containing wax particles, the curable resin composition can be light-moisture-curable and photocured before attaching the adherend as described later, thereby maintaining the thickness of the curable resin composition at a certain level or more at the time of bonding. This makes it easy to reduce the adhesive force by heating.

Additionally, the wax particles may have a functional group capable of reacting with the curable resin. By having a reactive functional group, the wax particles react with the curable resin when the curable resin is cured, and the wax particles are incorporated during crosslinking of the cured body. Therefore, when the wax is melted by heating, the crosslinking partially collapses, so that the adhesive strength at 100°C or 120°C is more effectively reduced.

For example, when the curable resin composition contains a moisture-curable resin as the curable resin, a hydroxyl group can be mentioned as a reactive functional group. The wax particles may, for example, have a functional group introduced to the surface of the particle. For example, when introducing a hydroxyl group to the surface of a wax particle, a wax having a hydroxyl group may be formed into particles in advance.

Specific examples of the wax particles include olefin waxes or paraffin waxes such as polypropylene wax, polyethylene wax, microcrystalline wax, and polyethylene oxide wax, carnauba wax, sasol wax, and montanate wax. aliphatic ester waxes, deacidified carnaba waxes, saturated aliphatic acid waxes such as palmitic acid, stearic acid, and montanic acid, unsaturated aliphatic acid waxes such as brassidic acid, eleostearic acid, and farinaric acid, and stearyl. Saturated alcohol-based waxes or aliphatic alcohol-based waxes such as alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, melisyl alcohol, polyhydric alcohol-based waxes such as sorbitol, linoleic acid amide, oleic acid amide, and lauric acid. Saturated fatty acid amide waxes such as acid amide, saturated fatty acid bisamide waxes such as methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, and hexamethylenebisstearic acid amide, ethylenebisoleic acid amide, and hexamethylenebisoleic acid amide. Unsaturated acid amide waxes such as methylenebisoleic acid amide, N,N'-dioleyladipic acid amide, N,N'-dioleylsebacic acid amide, m-xylenebisstearic acid amide, N,N'-distea Aromatic bisamide waxes such as lylisophthalic acid amide, graft-modified waxes made by graft polymerizing vinyl monomers such as styrene to polyolefin, partial ester waxes made by reacting fatty acids such as behenic acid monoglyceride with polyhydric alcohols, and vegetable waxes. Long-chain alkylacrylate waxes such as methyl ester waxes with hydroxyl groups obtained by hydrogenating fats and oils, ethylene/vinyl acetate copolymer waxes with a high content of ethylene component, and saturated stearyl acrylate waxes such as acrylic acid, Aromatic acrylate wax, such as benzyl acrylate wax, etc. are mentioned. Among them, olefin wax, paraffin wax, and Sasol wax are preferable.

The wax particles may be commercially available or non-commercially available. Additionally, commercially available wax particles may be pulverized to obtain wax particles having an appropriate average particle diameter and average particle diameter/average primary particle diameter. For example, wax particles obtained by pulverizing FNP-0090 (manufactured by Nippon Seiro) may be used.

The content of the wax particles is preferably 3 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more, with respect to 100 parts by mass of the curable resin composition. By setting the wax particle content above these lower limits, the adhesive force at 100°C or 120°C can be sufficiently low.

Moreover, the content of wax particles is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, with respect to 100 parts by mass of the curable resin composition. By keeping the wax particle content below these upper limits, the adhesive force at 80°C can be sufficiently high.

(Optical radical polymerization initiator)

When using a radically polymerizable compound, the curable resin composition of the present invention preferably contains a radical photopolymerization initiator in order to ensure photocurability.

Examples of the radical photopolymerization initiator include benzophenone-based compounds, acetphenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, and thioxanthone. .

Among the photoradical polymerization initiators, commercially available ones include, for example, IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 651, IRGACURE 784, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE01, Lucillin TPO (all manufactured by BASF) ), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.).

The content of the radical photopolymerization initiator in the curable resin composition is preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the radically polymerizable compound. When the content of the radical photopolymerization initiator is within this range, the curable resin composition obtained has excellent photocurability and storage stability. The content of the radical photopolymerization initiator is more preferably 0.1 parts by mass or more and 5 parts by mass or less.

(catalyst)

When the curable resin composition contains a moisture-curable resin, it may contain a catalyst that promotes the moisture-curing reaction of the moisture-curable resin. By using a catalyst, the curable resin composition becomes more excellent in moisture curing properties, making it possible to increase the adhesive strength at 80°C.

Specific catalysts include, for example, tin compounds such as din-butyltin dilaurate, din-butyltin diacetate, and tin octylate, triethylamine, U-CAT651M (manufactured by San Apro), U- CAT660M (manufactured by San-Apro), U-CAT2041 (manufactured by San-Apro), 1,4-diazabicyclo[2.2.2]octane, 2,6,7-trimethyl-1,4-diazabicyclo[2.2.2] Amine compounds such as octane, zinc compounds such as zinc octylate and zinc naphthenate, zirconium tetraacetylacetonate, copper naphthenate, cobalt naphthenate, etc. can be used.

The content of the catalyst is preferably 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the curable resin composition. When the catalyst content is within this range, the effect of promoting moisture curing reaction becomes more excellent without deteriorating the storage stability of the curable resin composition. The content of the catalyst is more preferably 0.2 parts by mass or more and 3 parts by mass or less.

(filler)

The curable resin composition of the present invention may contain a filler. By containing a filler, the curable resin composition of the present invention has appropriate thixotropic properties and can sufficiently maintain the shape after application. As a filler, a particle-type filler may be used.

As the filler, inorganic fillers are preferable, and examples include silica, talc, titanium oxide, zinc oxide, and calcium carbonate. Among them, silica is preferable because the resulting curable resin composition has excellent ultraviolet ray transparency. Additionally, the filler may be subjected to hydrophobic surface treatment such as silylation treatment, alkylation treatment, or epoxidation treatment.

Fillers may be used individually, or two or more types may be used in combination.

The content of the filler is preferably 1 part by mass or more and 20 parts by mass or less, more preferably 2 parts by mass or more and 15 parts by mass or less, and still more preferably 3 parts by mass or more and 10 parts by mass, with respect to 100 parts by mass of the curable resin composition. It is as follows.

The curable resin composition of the present invention may be diluted with a solvent as needed. When the curable resin composition is diluted with a solvent, the mass part of the curable resin composition is based on solid content, that is, it means the mass part excluding the solvent.

In addition to the components described above, the curable resin composition may contain additives such as light-shielding agents, colorants, metal-containing particles, and reactive diluents.

The viscosity of the curable resin composition is preferably 50 Pa·s or more and 1000 Pa·s or less. In addition, viscosity is the viscosity measured under the conditions of 25°C and 1rpm using a corn plate type viscometer. When the viscosity is within this range, workability when applying the curable resin composition to an adherend such as a substrate becomes more excellent. The viscosity is more preferably 80 Pa·s or more, further preferably 500 Pa·s or less, and even more preferably 400 Pa·s or less. Additionally, when the viscosity of the curable resin composition is too high, applicability can be improved by heating it during application.

As a method for producing the curable resin composition of the present invention, for example, using a mixer such as a homodisper, homomixer, universal mixer, planetary mixer, kneader, or three (3) roll, the curable resin is mixed as necessary. Examples include methods of mixing wax particles and other additives mixed accordingly.

Here, the temperature when mixing the various components is not particularly limited, but when mixing wax particles, it is preferably lower than the melting point of the wax particles, and more preferably 10°C or more lower than the melting point of the wax particles. By keeping the temperature at the time of mixing sufficiently lower than the melting point of the wax particles, the wax particles blended as the raw material do not aggregate or melt during production, and it becomes possible to exist in the same state as the raw material in the curable resin composition. Therefore, it becomes easy to adjust the wax particles so that they have a desired average particle diameter and average particle diameter/average primary particle diameter.

The cured body of the present invention is obtained by curing the curable resin composition described above. Since the cured body of the present invention has an adhesive strength at 80°C and at least one of 100°C and 120°C within the above range, it is excellent in adhesive performance and reworkability as described above.

In addition, each component contained in the cured body of the present invention is a component contained in the curable resin composition of the present invention and a component changed by a chemical reaction or the like during curing. Therefore, when the curable resin composition has wax particles, the cured body of the present invention also has wax particles. Here, the curable resin composition is preferably cured without heating, and is preferably heated to an extent that the wax particles do not melt or agglomerate even when heated for curing. Therefore, the cured body may also contain wax particles having the average particle diameter and average particle diameter/average primary particle diameter shown above. In addition, the cured body of the present invention may have a storage elastic modulus ratio and a storage elastic modulus at 25°C within the above-mentioned range.

The cured body of the present invention exhibits the above-described adhesive force when the curable resin composition is cured, thereby bonding adherends. Curing of the curable resin composition may be performed appropriately depending on the type of curable resin. For example, in the case of photocuring, it can be cured by irradiating various types of light such as ultraviolet rays, and in the case of moisture curing, it can be cured by leaving it in the air.

In addition, in the case of light-moisture curing properties, the photocurable resin is first cured by irradiating light such as ultraviolet rays, for example, to provide relatively low adhesive strength. At this time, the photocured curable resin composition may have adhesiveness. Next, the cured product may be cured by moisture by leaving it in the air to obtain a cured product with sufficient adhesive strength.

To explain in more detail, for example, when joining two adherends, first, the curable resin composition of the present invention is applied to one adherend, and then the photocurable resin in the curable resin composition is irradiated with light. By curing, the curable resin composition is adhered to one adherend with a relatively low adhesive force. Next, the other adherend is attached to one adherend through the photocured curable resin composition, and then left in the air, etc., so that the curable resin composition is hardened by moisture and sufficient adhesive strength is achieved. The two adherends are joined together.

After the curable resin composition of the present invention is cured as described above to form a cured product, the adhesive strength decreases when heated. Therefore, by heating, it becomes possible to easily peel off the adherend and rejoin (rework) the adherend.

Here, the heating during rework just needs to be higher than 80°C. By setting the temperature higher than 80°C, the adhesive strength of the curable resin composition of the present invention is lowered, so that the adherend can be easily peeled off. Additionally, heating during rework is preferably 120°C or lower. By setting the temperature to 120°C or lower, the adherend can be easily peeled off without damaging the adhesive portion or electronic components around the adhesive portion. From these viewpoints, the heating temperature during rework is preferably 90°C or higher, and more preferably 95°C or higher. Moreover, 110 degrees C or less is preferable, and 105 degrees C or less is more preferable.

Additionally, when the curable resin composition contains wax particles, the heating during rework is preferably higher than the melting point of the wax particles, and more preferably 10°C or more higher than the melting point of the wax particles. By heating to a temperature higher than the melting point of the wax particles, the adhesive strength is moderately reduced.

The curable resin composition of the present invention is used, for example, to bond various members (adherents) constituting various electronic devices or electronic components. Examples of the adherend include various adherends such as metal, glass, and plastic. The shape of the adherend is not particularly limited, and examples include film, sheet, plate, panel, tray, rod, box, and housing.

For example, the curable resin composition of the present invention is used to bond members constituting electronic components. As a result, the electronic component has the hardened body of the present invention. In such electronic components, various members are joined with high adhesive strength by the cured body of the present invention. In addition, since the adhesive strength of the cured body is lowered by heating to a relatively low temperature, it has excellent reworkability and makes it possible to easily rejoin the electronic components without damaging them.

In addition, the curable resin composition of the present invention is used inside electronic devices, for example, to obtain assembled parts by bonding substrates to substrates. The assembled part obtained in this way has a first substrate, a second substrate, and the cured body of the present invention, and at least a part of the first substrate is bonded to at least a part of the second substrate via the cured body. Additionally, the first substrate and the second substrate are preferably each equipped with at least one electronic component.

In such assembled parts, the first and second substrates are bonded to the cured body of the present invention with higher adhesive force. In addition, the cured body has excellent reworkability because the adhesive strength is lowered by heating to a relatively low temperature, and it becomes possible to easily rejoin the substrates without damaging the electronic components installed on the substrate.

[Example]

Although the present invention will be described in more detail by way of examples, the present invention is not limited in any way by these examples.

In this example, various physical properties were evaluated as follows.

(Average particle diameter, average particle diameter/average primary particle diameter)

The average particle diameter of the wax particles contained in the curable resin composition obtained in each example and comparative example, and the ratio of the average particle diameter to the average primary particle diameter (average particle diameter/average primary particle diameter) were measured according to the method described in the specification. .

(adhesiveness)

According to the method described in the specification, the adhesive strength of the curable resin composition obtained in each example and comparative example was measured at 80°C, 100°C, and 120°C.

(storage modulus)

According to the method described in the specification, the storage elastic modulus of the curable resin composition obtained in the examples and comparative examples was measured, and the storage elastic modulus at 80°C relative to the storage elastic modulus at 25°C and the storage elastic modulus at 120°C found the rain.

(volume ratio)

Using a laser microscope, the volumes of the curable resin composition at 25°C, 100°C, and 120°C were measured, and the ratio of the volume at 100°C to the volume at 25°C and the ratio of the volume at 120°C to the volume at 25°C were determined. Saved.

The moisture-curable urethane resin used in each Example and Comparative Example was produced according to Synthesis Example 1 below.

[Synthesis Example 1]

As a polyol compound, 100 parts by mass of polytetramethylene ether glycol (manufactured by Mitsubishi Chemical Corporation, brand name "PTMG-2000") and 0.01 parts by mass of dibutyltin dilaurate were placed in a separable flask with a capacity of 500 mL under vacuum (20 mmHg or less). , and mixed by stirring at 100°C for 30 minutes. Afterwards, at normal pressure, 26.5 parts by mass of diphenylmethane diisocyanate (manufactured by Nisso Corporation, brand name "Pure MDI") was added as a polyisocyanate compound, stirred at 80°C for 3 hours to react, and moisture-curable urethane resin (weight average molecular weight 2700) was added. ) was obtained.

Components other than the moisture-curable urethane resin used in each Example and Comparative Example were as follows.

(Radical polymerizable compound)

Urethane acrylate: manufactured by Daicel Allnex, brand name “EBECRYL 8411”, bifunctional

Phenoxyethyl acrylate: manufactured by Kyoeisha Chemical Company, brand name “Light Acrylate PO-A”, monofunctional

Lauryl acrylate: manufactured by Kyoeisha Chemical Company, brand name “Light Acrylate L-A”, monofunctional

(wax particles)

Finely ground polyolefin wax (1): FNP-0090 (brand name, manufactured by Nippon Seiro) finely ground to a primary particle size of 1 to 10 μm to prevent agglomeration, melting point: 92°C

Finely ground polyolefin wax (2): FNP-0090 (brand name, manufactured by Nippon Seiro) finely ground to a primary particle size of 1 to 10 μm and a secondary particle size of 30 to 200 μm, melting point: 92°C

Finely ground polyolefin wax (3): FNP-0090 (brand name, manufactured by Nippon Seiro) finely ground to a primary particle size of 100 to 200 μm to prevent agglomeration, melting point: 92°C

(Optical radical polymerization initiator)

2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (manufactured by BASF, brand name “IRGACURE 369”)

(catalyst)

U-CAT 660M (Product name, manufactured by San-Apro)

(filler)

Trimethylsilylated silica (Japanese Aelozil company, brand name “R812”, primary particle size 7 nm)

[Examples 1 to 3, Comparative Examples 1, 2, 3]

According to the mixing ratio shown in Table 1, each material was stirred at a temperature of 50°C with a planetary stirring device (“Awatori Rentaro” manufactured by Shinki Co., Ltd.), and then mixed uniformly at a temperature of 50°C with a ceramic three-roll to prepare Examples 1 to 1. 3, the curable resin compositions of Comparative Examples 1 to 3 were obtained.

As shown in Table 1, in each example, the adhesive strength at 80°C can be increased, while the adhesive strength at 100°C and 120°C is lowered, resulting in high adhesive performance and good reworkability. there was. On the other hand, in Comparative Examples 1 to 3, the adhesion at 100°C and 120°C could not be lowered, so the reworkability could not be improved.

Claims (11)

In the following adhesion test, the adhesion at 80°C is 6 kgf/cm ² or more and 25 kgf/cm ² or less, and the adhesion at 120°C is 0.1 kgf/cm ² or more and 3.5 kgf/cm ² or less,
The ratio of the volume at 120°C to the volume at 25°C is 0.9 or more and 1.2 or less,
A curable resin composition containing wax particles, wherein the ratio of the average particle diameter to the average primary particle diameter of the wax particles is 1 or more and 3 or less, and the average particle diameter of the wax particles is 0.1 μm or more and 100 μm or less.
＜Adhesion test＞
A curable resin composition is applied to an aluminum substrate so that the width is 1.0 ± 0.1 mm, the length is 25 ± 2 mm, and the thickness is 0.4 ± 0.1 mm, and then a glass plate is overlapped to cure the curable resin composition, and the aluminum substrate and the glass plate are Attach to produce a sample for adhesion testing. The prepared adhesion test sample was heated to 80°C by placing it in an 80°C atmosphere for 10 minutes, and then stretched in the shear direction at a speed of 5 mm/sec using a tensile tester in an 80°C atmosphere to ensure that the aluminum substrate and the glass plate were peeled off. The strength of the stain is measured to measure the adhesive force at 80°C. Additionally, the adhesive force at 120°C was measured in the same manner except that the heating temperature was changed to 120°C. In the following adhesion test, the adhesion at 80°C is 6 kgf/cm ² or more and 25 kgf/cm ² or less, and the adhesion at 100°C is 0.1 kgf/cm ² or more and 4 kgf/cm ² or less,
The ratio of the volume at 100°C to the volume at 25°C is 0.9 or more and 1.2 or less,
A curable resin composition containing wax particles, wherein the ratio of the average particle diameter to the average primary particle diameter of the wax particles is 1 or more and 3 or less, and the average particle diameter of the wax particles is 0.1 μm or more and 100 μm or less.
＜Adhesion test＞
A curable resin composition is applied to an aluminum substrate so that the width is 1.0 ± 0.1 mm, the length is 25 ± 2 mm, and the thickness is 0.4 ± 0.1 mm, and then a glass plate is overlapped to cure the curable resin composition, and the aluminum substrate and the glass plate are Attach to produce a sample for adhesion testing. The prepared adhesion test sample was placed in an atmosphere of 80°C for 10 minutes, heated to 80°C, and stretched in the shear direction at a speed of 5 mm/sec using a tensile tester in an atmosphere of 80°C to ensure that the aluminum substrate and the glass plate were peeled off. The strength when applied is measured to measure the adhesive force at 80°C. Additionally, the adhesive force at 100°C was measured in the same manner except that the heating temperature was changed to 100°C. In claim 1 or claim 2,
A curable resin composition wherein the ratio of the storage elastic modulus at 80°C to the storage elastic modulus at 120°C is 1.5 or more and 15 or less, and the storage elastic modulus at 25°C is 1.0×10 ⁵ Pa or more and 1.0×10 ⁸ Pa or less. In claim 1 or claim 2,
A curable resin composition wherein the wax particles have a melting point of 80°C or more and 110°C or less. A cured product of the curable resin composition according to claim 1 or 2. An electronic component having the hardened body according to claim 5. It has a first substrate, a second substrate, and a cured body according to claim 5,
An assembled part in which at least a part of the first substrate is bonded to at least a part of the second substrate via the cured body. In claim 7,
The first substrate and the second substrate are each equipped with at least one electronic component. delete delete delete

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