WO2021241548A1 - Curable resin composition, adhesive, adhesive varnish, adhesive film, and cured object - Google Patents

Abstract

One purpose of the present invention is to provide a curable resin composition having excellent applicability by spin coating and giving cured objects which are excellent in terms of adhesiveness and long-term heat resistance. Another purpose of the present invention is to provide: an adhesive, an adhesive varnish, and an adhesive film each including or obtained from the curable resin composition; and a cured object obtained from the curable resin composition. This curable resin composition has a viscosity at 25°C of 200-600 mPa·s and a thixotropic index at 25°C of 2.0 or less and gives a cured object on a silicon chip, the cured object having initial adhesion force on the silicon chip of 3 MPa or greater and, after 100-hour storage at 150°C, having adhesion force on the silicon chip of 2 MPa or greater.

Description

Curable resin composition, adhesive, adhesive varnish, adhesive film, and cured product

The present invention relates to a curable resin composition having excellent coatability by a spin coating method, adhesiveness of a cured product, and long-term heat resistance. The present invention also relates to an adhesive, an adhesive varnish, and an adhesive film made of the curable resin composition, and a cured product of the curable resin composition.

Curable resins such as epoxy resins, which have low shrinkage and are excellent in adhesiveness, insulation, and chemical resistance, are used in many industrial products. In particular, in electronic equipment applications, curable resin compositions that give good results in a solder reflow test for short-time heat resistance and a cold-heat cycle test for repeated heat resistance are often used. As a curable resin composition having excellent heat resistance and adhesiveness, for example, Patent Documents 1 and 2 disclose a curable resin composition containing an epoxy resin and an imide compound as a curing agent.

Japanese Unexamined Patent Publication No. 61-270852 Japanese Patent Publication No. 2004-502859

As a method of adhering a base material and an adherend with an adhesive varnish using a curable resin composition, a varnish is applied onto the base material by a spin coating method, and then the adherend is layered to cure the varnish. There is a way to make it. By using such a coating method by the spin coating method, the adhesive layer can be easily formed at low cost. However, when a conventional curable resin composition having excellent heat resistance and adhesiveness is applied by a spin coating method, there is a problem that the coating film does not spread sufficiently and a uniform coating film cannot be obtained. Therefore, there has been a demand for a curable resin composition that can be uniformly applied by the spin coating method and has excellent adhesiveness and long-term heat resistance of the cured product.

An object of the present invention is to provide a curable resin composition having excellent coatability by a spin coating method, adhesiveness of a cured product, and long-term heat resistance. Another object of the present invention is to provide an adhesive, an adhesive varnish, and an adhesive film using the curable resin composition, and a cured product of the curable resin composition.

In the present invention, the viscosity at 25 ° C. is 200 mPa · s or more and 600 mPa · s or less, the thixotropic index at 25 ° C. is 2.0 or less, the initial adhesive force of the cured product to the silicon chip is 3 MPa or more, and , A curable resin composition having an adhesive strength of a cured product to a silicon chip of 2 MPa or more after being stored at 150 ° C. for 100 hours.
The present invention will be described in detail below.

The present inventors have a viscosity at 25 ° C., a thixotropic index at 25 ° C., an initial adhesive force of the cured product to a silicon chip, and silicon of the cured product after storage at 150 ° C. for 100 hours in the curable resin composition. It was examined to keep the adhesive strength to the chip within a specific range. As a result, it has been found that a curable resin composition having excellent coatability by the spin coating method, adhesiveness of the cured product and long-term heat resistance can be obtained, and the present invention has been completed.

The curable resin composition of the present invention has a lower limit of viscosity of 200 mPa · s and an upper limit of 600 mPa · s at 25 ° C. When the viscosity is in this range, the curable resin composition of the present invention is excellent in coatability by the spin coating method. The preferable lower limit of the viscosity is 220 mPa · s, and the preferred upper limit is 550 mPa · s.
In the present specification, the above-mentioned "viscosity" means a value measured under the condition of 10 rpm using an E-type viscometer. Examples of the E-type viscometer include VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.), and a CP1 type cone plate can be used.

The curable resin composition of the present invention preferably has a viscosity of 2.0 times or less the initial viscosity after being stored at 25 ° C. for 8 days. When the viscosity after storage at 25 ° C. for 8 days is 2.0 times or less the initial viscosity, the curable resin composition of the present invention has excellent storage stability. The viscosity after storage at 25 ° C. for 8 days is preferably 1.5 times or less, more preferably 1.3 times or less the initial viscosity.
In the present specification, the above-mentioned "initial viscosity" means the viscosity of the curable resin composition measured at 25 ° C. within 60 minutes after production or within 30 minutes after thawing when stored frozen. Further, the above-mentioned "viscosity after storage at 25 ° C. for 8 days" is a curable resin composition measured at 25 ° C. after being manufactured or thawed after being stored frozen and then stored at 25 ° C. for 8 days. Means viscosity.

The curable resin composition of the present invention has an upper limit of the thixotropic index at 25 ° C. of 2.0. When the thixotropic index is 2.0 or less, the curable resin composition of the present invention has excellent coatability by the spin coating method. The preferred upper limit of the thixotropic index is 1.9, and the more preferable upper limit is 1.8.
Further, the lower limit of the thixotropic index is not particularly preferable, but the practical lower limit is 1.0.
In the present specification, the above-mentioned "thixotropic index" means a value obtained by dividing the viscosity measured under the condition of 1.0 rpm using an E-type viscometer by the viscosity measured under the condition of 10 rpm.

In the curable resin composition of the present invention, the lower limit of the initial adhesive force of the cured product to the silicon chip is 3 MPa. When the initial adhesive force of the cured product to the silicon chip is 3 MPa or more, the curable resin composition of the present invention can be suitably used for bonding electronic components. The preferable lower limit of the initial adhesive force of the cured product to the silicon chip is 3.2 MPa.
There is no particular preferable upper limit of the initial adhesive force of the cured product to the silicon chip, but the practical upper limit is 4.6 MPa.
The initial adhesive force of the cured product to the silicon chip can be measured by the following method.
That is, first, the curable resin composition is applied to the polyimide substrate, and the silicon chips are laminated. Then, the curable resin composition is cured by heating at 190 ° C. for 1 hour to obtain a test piece. The obtained test piece is measured for die shear strength at 25 ° C. at a speed of 100 μm / s and a test height of 100 μm using a die shear tester. The obtained die shear strength is used as the initial adhesive force of the cured product to the silicon chip. As the polyimide, Kapton 200H (manufactured by Toray Industries, Inc., surface roughness 0.03 to 0.07 μm) can be used, and as the silicon chip, a silicon chip manufactured by Global Wafer Co., Ltd. (surface roughness 0. 5 to 1.0 nm) can be used. Further, as the die share tester, DAGE4000 (manufactured by Nordson) can be used.

In the curable resin composition of the present invention, the lower limit of the adhesive force of the cured product to the silicon chip after storage at 150 ° C. for 100 hours is 2 MPa. When the adhesive strength of the cured product to the silicon chip after storage at 150 ° C. for 100 hours is 2 MPa or more, the curable resin composition of the present invention can be suitably used for adhering electronic components. .. The preferable lower limit of the adhesive force of the cured product after storage at 150 ° C. for 100 hours with respect to the silicon chip is 2.1 MPa, and the more preferable lower limit is 2.2 MPa.
There is no particular preferable upper limit of the adhesive strength of the cured product after storage at 150 ° C. for 100 hours to the silicon chip, but the practical upper limit is 4.6 MPa.
The adhesive strength of the cured product after storage at 150 ° C. for 100 hours can be measured by the following method.
That is, first, the test piece obtained in the same manner as the above-mentioned "initial adhesive force of the cured product to the silicon chip" is stored in an oven at 150 ° C. for 100 hours. Next, the die shear strength of the stored test piece is measured at a speed of 100 μm / s and a test height of 100 μm at 25 ° C. using a die shear tester. The obtained die shear strength is used as the adhesive strength to the silicon chip of the cured product after being stored at 150 ° C. for 100 hours.

In the curable resin composition of the present invention, the viscosity, the thixotropic index, the initial adhesive force of the cured product to the silicon chip, and the adhesive force of the cured product to the silicon chip after storage at 150 ° C. for 100 hours are within the above-mentioned ranges. A method of adjusting the type of each constituent component contained in the curable resin composition and the content ratio thereof is preferable.

The curable resin composition of the present invention preferably contains a curable resin and a curing agent. In particular, the curable resin composition of the present invention is preferably a thermosetting resin composition, and more preferably contains a curable resin and a thermosetting agent as a curing agent.

Examples of the curable resin include epoxy resin, acrylic resin, phenol resin, cyanate resin, isocyanate resin, maleimide resin, benzoxazine resin, silicone resin, fluororesin and the like. Among them, the curable resin preferably contains an epoxy resin. Further, these curable resins may be used alone or in combination of two or more.
Further, the curable resin is preferably liquid or semi-solid at 25 ° C. because it is easier to set the viscosity and the thixotropic index of the obtained curable resin composition within the above ranges. It is more preferable that it is liquid at 25 ° C.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2'-diallyl bisphenol A type epoxy resin, and hydrogenated bisphenol type epoxy resin. , Propoxy oxide-added bisphenol A type epoxy resin, triazine 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, fluorene type epoxy Resin, naphthylene ether type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthalenephenol novolac type epoxy resin, glycidylamine type epoxy resin, alkyl Examples thereof include a polyol type epoxy resin, a rubber-modified epoxy resin, and a glycidyl ester compound. In particular, since it becomes easier to set the viscosity and thixotropic index of the obtained curable resin composition within the above-mentioned ranges, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, and resorcinol. Type epoxy resin and triazine type epoxy resin are preferable.

Examples of the heat-curing agent include an imide skeleton in the main chain, an imide oligomer having a crosslinkable functional group at the end, an acid anhydride-based curing agent, a phenol-based curing agent, a thiol-based curing agent, an amine-based curing agent, and a cyanate-based. Examples thereof include a curing agent and an active ester-based curing agent. Among them, the thermosetting agent preferably contains an imide oligomer from the viewpoint of adhesiveness and long-term heat resistance of the cured product of the obtained curable resin composition. Further, the curable resin composition of the present invention is more excellent in adhesiveness and long-term heat resistance of the cured product, and it is easier to set the viscosity and the thixotropic index in the above-mentioned range. It is preferable that the curing agent contains an imide oligomer and also contains a polymer compound described later.

The imide oligomer preferably has a structure represented by the following formula (1-1) or the following formula (1-2) as a structure containing the crosslinkable functional group. By having the structure represented by the following formula (1-1) or the following formula (1-2), the imide oligomer is excellent in reactivity and compatibility with a curable resin such as an epoxy resin.

In formulas (1-1) and (1-2), A is an acid dianhydride residue, and in formula (1-1), B is an aliphatic diamine residue or an aromatic diamine residue. Yes, in formula (1-2), Ar is a optionally substituted divalent aromatic group.

The acid dianhydride residue is preferably a tetravalent group represented by the following formula (2-1) or the following formula (2-2).

In the formula (2-1) and the formula (2-2), * is a bond position, and in the formula (2-1), Z is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, and a bond. A linear or branched divalent hydrocarbon group that may have an oxygen atom at the position, or a divalent group that has an aromatic ring that may have an oxygen atom at the bond position. .. The hydrogen atom of the aromatic ring in the formula (2-1) and the formula (2-2) may be substituted.

Z in the above formula (2-1) has a linear or branched divalent hydrocarbon group which may have an oxygen atom at the bond position, or an oxygen atom at the bond position. If it is a divalent group having a optionally aromatic ring, these groups may be substituted.
A linear or branched divalent hydrocarbon group which may have an oxygen atom at the bond position, or a divalent divalent group having an aromatic ring which may have an oxygen atom at the bond position. When the group is substituted, examples of the substituent include a halogen atom, a linear or branched alkyl group, a linear or branched alkenyl group, an alicyclic group, an aryl group and an alkoxy group. , Nitro group, cyano group and the like.

Examples of the acid dianhydride from which the acid dianhydride residue is derived include an acid dianhydride represented by the formula (8) described later.

When B in the above formula (1-1) is the above aliphatic diamine residue, the preferable lower limit of the carbon number of the aliphatic diamine residue is 4. When the aliphatic diamine residue has 4 or more carbon atoms, the obtained thermosetting adhesive film is excellent in handleability before curing and dielectric properties after curing. The more preferable lower limit of the number of carbon atoms of the aliphatic diamine residue is 5, and the more preferable lower limit is 6.
Further, although there is no particular preferable upper limit of the carbon number of the aliphatic diamine residue and the aliphatic triamine residue, the practical upper limit is 60.

Examples of the aliphatic diamine from which the above aliphatic diamine residue is derived include an aliphatic diamine derived from dimer acid, a linear or branched aliphatic diamine, an aliphatic ether diamine, and an aliphatic alicyclic type. Examples include diamine.
Examples of the aliphatic diamine derived from the dimer acid include dimer diamine and hydrogenated diamine diamine.
Examples of the linear or branched aliphatic diamine include 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonandiamine, 1,10-decanediamine, and 1, 11-Undecanediamine, 1,12-Dodecanediamine, 1,14-Tetradecanediamine, 1,16-Hexadecanediamine, 1,18-Octadecanediamine, 1,20-Eicosandiamine, 2-Methyl-1,8-octane Examples thereof include diamine, 2-methyl-1,9-nonanediamine, 2,7-dimethyl-1,8-octanediamine and the like.
Examples of the aliphatic ether diamine include 2,2'-oxybis (ethylamine), 3,3'-oxybis (propylamine), 1,2-bis (2-aminoethoxy) ethane and the like.
Examples of the aliphatic alicyclic diamine include 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine.
Among them, the aliphatic diamine residue is preferably an aliphatic diamine residue derived from the dimer acid.

When B in the above formula (1-1) is the above aromatic diamine residue, the aromatic diamine residue is a divalent represented by the following formula (3-1) or the following formula (3-2). It is preferably the basis of.

In the formula (3-1) and the formula (3-2), * is a bond position, and in the formula (3-1), Y is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, and a bond. A linear or branched divalent hydrocarbon group that may have an oxygen atom at the position, or a divalent group that has an aromatic ring that may have an oxygen atom at the bond position. .. The hydrogen atom of the aromatic ring in the formula (3-1) and the formula (3-2) may be substituted.

Y in the above formula (3-1) has a linear or branched divalent hydrocarbon group which may have an oxygen atom at the bond position, or an oxygen atom at the bond position. If it is a divalent group having a optionally aromatic ring, these groups may be substituted.
A linear or branched divalent hydrocarbon group which may have an oxygen atom at the bond position, or a divalent divalent group having an aromatic ring which may have an oxygen atom at the bond position. When the group is substituted, examples of the substituent include a halogen atom, a linear or branched alkyl group, a linear or branched alkenyl group, an alicyclic group, an aryl group and an alkoxy group. , Nitro group, cyano group and the like.

Examples of the aromatic diamine from which the aromatic diamine residue is derived include those in which the diamine represented by the formula (9) described later is an aromatic diamine.

Further, when the imide oligomer has a siloxane skeleton in the structure, it may lower the glass transition temperature after curing or contaminate the adherend and cause poor adhesion. Therefore, the imide oligomer has a siloxane skeleton in the structure. It is preferably not an imide oligomer.

The number average molecular weight of the imide oligomer is preferably 4000 or less. When the number average molecular weight of the imide oligomer is 4000 or less, the cured product of the obtained curable resin composition is superior in long-term heat resistance. A more preferable upper limit of the number average molecular weight of the imide oligomer is 3400, and a further preferable upper limit is 2800.
In particular, the number average molecular weight of the imide oligomer is preferably 900 or more and 4000 or less when the structure is represented by the above formula (1-1), and the structure represented by the above formula (1-2) is preferable. If it has, it is preferably 550 or more and 4000 or less. When the structure is represented by the above formula (1-1), the more preferable lower limit of the number average molecular weight is 950, and the more preferable lower limit is 1000. When the structure represented by the above formula (1-2) is provided, the more preferable lower limit of the number average molecular weight is 580, and the further preferable lower limit is 600.
In the present specification, the above-mentioned "number average molecular weight" is a value obtained by measuring by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and converting it into polystyrene. Examples of the column used when measuring the number average molecular weight in terms of polystyrene by GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industry Co., Ltd.).

Specifically, the imide oligomer is an imide oligomer represented by the following formula (4-1), the following formula (4-2), the following formula (4-3), or the following formula (4-4). Alternatively, it is preferably an imide oligomer represented by the following formula (5-1), the following formula (5-2), the following formula (5-3), or the following formula (5-4).

In formulas (4-1) to (4-4), A is the acid dianhydride residue, and in formulas (4-1), formula (4-3), and formula (4-4). , A may be the same or different from each other. In formulas (4-1) to (4-4), B is the aliphatic diamine residue or the aromatic diamine residue, and in formulas (4-3) and (4-4), B is. , Each may be the same or different. In the formula (4-2), X is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may be substituted, and in the formula (4-4), W is a hydrogen atom, a halogen atom. , Or a monovalent hydrocarbon group which may be substituted.

In formulas (5-1) to (5-4), A is the acid dianhydride residue, and in formulas (5-3) and (5-4), A is the same. It may or may not be different. In formulas (5-1) to (5-4), R is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may be substituted, and formulas (5-1) and (5). -3) In the middle, R may be the same or different. In the formula (5-2) and the formula (5-4), W is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may be substituted, and the formula (5-3) and the formula (5-3). In 5-4), B is the aliphatic diamine residue or the aromatic diamine residue.

A in the above formulas (4-1) to (4-4) and the above formulas (5-1) to (5-4) is the following formula (6-1) or the following formula (6-2). It is preferably a tetravalent group represented.

In the formula (6-1) and the formula (6-2), * is a bond position, and in the formula (6-1), Z is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, and a bond. A linear or branched divalent hydrocarbon group that may have an oxygen atom at the position, or a divalent group that has an aromatic ring that may have an oxygen atom at the bond position. .. The hydrogen atom of the aromatic ring in the formula (6-1) and the formula (6-2) may be substituted.

B in the above formulas (4-1) to (4-4), and the above formulas (5-3) and (5-4) is the following formula (7-1) or the following formula (7-2). It is preferably a divalent group represented by.

In the formula (7-1) and the formula (7-2), * is a bond position, and in the formula (7-1), Y is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, and a bond. A linear or branched divalent hydrocarbon group that may have an oxygen atom at the position, or a divalent group that has an aromatic ring that may have an oxygen atom at the bond position. .. The hydrogen atom of the aromatic ring in the formula (7-1) and the formula (7-2) may be substituted.

As a method for producing an imide oligomer having a structure represented by the above formula (1-1), for example, an acid dianhydride represented by the following formula (8) and a diamine represented by the following formula (9) are used. A method of reacting with the above can be mentioned.

In formula (8), A is the same tetravalent group as A in formula (1-1) above.

In the formula (9), B is the same divalent group as B in the above formula (1-1), and R ¹ to R ⁴ are independently hydrogen atoms or monovalent hydrocarbon groups, respectively. ..

Specific examples of the method for reacting the acid dianhydride represented by the above formula (8) with the diamine represented by the above formula (9) are shown below.
First, the diamine represented by the above formula (9) is previously dissolved in a solvent (for example, N-methylpyrrolidone) in which the amic acid oligomer obtained by the reaction is soluble, and the above formula (8) is added to the obtained solution. The acid dianhydride represented by is added and reacted to obtain an amic acid oligomer solution. Then, a method of removing the solvent by heating, depressurization or the like, and further heating at about 200 ° C. or higher for 1 hour or longer to react the amic acid oligomer and the like can be mentioned. By adjusting the molar ratio of the acid dianhydride represented by the above formula (8) and the diamine represented by the above formula (9) and the imidization conditions, the desired number average molecular weight can be obtained. An imide oligomer having a structure represented by the above formula (1-1) can be obtained at the end.
Further, by substituting a part of the acid anhydride represented by the above formula (8) with the acid anhydride represented by the following formula (10), it has a desired number average molecular weight and has the above-mentioned number average molecular weight at one end. An imide oligomer having a structure represented by the formula (1-1) and having a structure derived from an acid anhydride represented by the following formula (10) at the other end can be obtained. In this case, the acid dianhydride represented by the above formula (8) and the acid anhydride represented by the following formula (10) may be added at the same time or separately.
Further, by substituting a part of the diamine represented by the above formula (9) with a monoamine represented by the following formula (11), it has a desired number average molecular weight and has the above formula (1-1) at one end. ), And an imide oligomer having a structure derived from a monoamine represented by the following formula (11) at the other end can be obtained. In this case, the diamine represented by the above formula (9) and the monoamine represented by the following formula (11) may be added at the same time or separately.

In formula (10), Ar is a divalent aromatic group that may be substituted.

In formula (11), Ar is a optionally substituted monovalent aromatic group, and R ⁵ and R ⁶ are independently hydrogen atoms or monovalent hydrocarbon groups, respectively.

As a method for producing an imide oligomer having a structure represented by the above formula (1-2), for example, an acid dianhydride represented by the above formula (8) and a phenolic oligomer represented by the following formula (12) are used. Examples thereof include a method of reacting with a hydroxyl group-containing monoamine.

In formula (12), Ar is a optionally substituted divalent aromatic group, and R ⁷ and R ⁸ are independently hydrogen atoms or monovalent hydrocarbon groups, respectively.

Specific examples of the method for reacting the acid dianhydride represented by the above formula (8) with the phenolic hydroxyl group-containing monoamine represented by the above formula (12) are shown below.
First, the phenolic hydroxyl group-containing monoamine represented by the above formula (12) is previously dissolved in a solvent (for example, N-methylpyrrolidone) in which the amic acid oligomer obtained by the reaction is soluble, and the above solution is used. The acid dianhydride represented by the formula (8) is added and reacted to obtain an amic acid oligomer solution. Then, a method of removing the solvent by heating, depressurization or the like, and further heating at about 200 ° C. or higher for 1 hour or longer to react the amic acid oligomer and the like can be mentioned. By adjusting the molar ratio of the acid dianhydride represented by the above formula (8) to the phenolic hydroxyl group-containing monoamine represented by the above formula (12) and the imidization conditions, the desired number average molecular weight can be obtained. It is possible to obtain an imide oligomer having a structure represented by the above formula (1-2) at both ends.
Further, by substituting a part of the phenolic hydroxyl group-containing monoamine represented by the above formula (12) with the monoamine represented by the above formula (11), it has a desired number average molecular weight and has the above formula at one end. An imide oligomer having a structure represented by (1-2) and having a structure derived from a monoamine represented by the above formula (11) at the other end can be obtained. In this case, the phenolic hydroxyl group-containing monoamine represented by the above formula (12) and the monoamine represented by the above formula (11) may be added at the same time or separately.

Examples of the acid dianhydride represented by the above formula (8) include pyromellitic acid dianhydride, 3,3'-oxydiphthalic acid dianhydride, 3,4'-oxydiphthalic acid dianhydride, 4,4. '-Oxydiphthalic acid dianhydride, 4,4'-(4,4'-isopropylidene diphenoxy) diphthalic acid anhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenyl ether dianhydride, p. -Phenylenebis (trimeritate anhydride), 2,3,3', 4'-biphenyltetracarboxylic acid dianhydride and the like can be mentioned.
Among them, aromatic acid dianhydride having a melting point of 240 ° C. or lower is preferable as the acid dianhydride used as a raw material of the imide oligomer because it is more excellent in solubility and heat resistance, and the melting point is 220 ° C. The following aromatic acid dianhydrides are more preferred, aromatic acid dianhydrides having a melting point of 200 ° C. or lower are even more preferred, and 3,4'-oxydiphthalic acid dianhydrides (melting point 180 ° C.), 4,4'. -(4,4'-Isopropylidene diphenoxy) diphthalic anhydride (melting point 190 ° C.) is particularly preferable.
In the present specification, the above-mentioned "melting point" means a value measured as the temperature of the endothermic peak when the temperature is raised at 10 ° C./min using a differential scanning calorimeter. Examples of the differential scanning calorimeter include EXTER DSC6100 (manufactured by SII Nanotechnology).

Examples of the diamine represented by the above formula (9) include 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl ether, and 3,4. '-Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenylsulphon, 4,4'-diaminodiphenylsulphon, 1,3- Bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, bis (4- (4-aminophenoxy) phenyl) methane, 2 , 2-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene, 1,4-bis (2- (4-amino) Phenyl) -2-propyl) benzene, 3,3'-diamino-4,4'-dihydroxyphenylmethane, 4,4'-diamino-3,3'-dihydroxyphenylmethane, 3,3'-diamino-4, 4'-Dihydroxyphenyl ether, bisaminophenylfluorene, bistoluidinefluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-diamino-3,3'-dihydroxyphenyl ether, 3,3' -Diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl and the like can be mentioned. Among them, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene, 1,4 because of its excellent availability. -Bis (2- (4-aminophenyl) -2-propyl) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis ( 4-Aminophenoxy) benzene is preferable, and since it is excellent in solubility and heat resistance, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene and 1,4-bis (2- (2- ( 4-Aminophenyl) -2-propyl) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene Is more preferable.

Examples of the acid anhydride represented by the above formula (10) include phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 1,2-naphthalanhydride, and 2,3-naphthal. Acid Anhydride, 1,8-Naphthalic Acid Anhydride, 2,3-Anthracendicarboxylic Acid Anhydride, 4-tert-butylphthalic Acid Anhydride, 4-Etinylphthalic Acid Anhydride, 4-Phenylethynylphthalic Acid Anhydride, Examples thereof include 4-fluorophthalic anhydride, 4-chlorophthalic anhydride, 4-bromophthalic anhydride, 3,4-dichlorophthalic anhydride and the like.

Examples of the monoamine represented by the above formula (11) include aniline, o-toluidine, m-toluidine, p-toluidine, 2,4-dimethylaniline, 3,4-dimethylaniline, and 3,5-dimethylaniline. 2-tert-butylaniline, 3-tert-butylaniline, 4-tert-butylaniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, 1-aminopyrene, 3- Chloroaniline, o-aniline, m-anisidine, p-anisidine, 1-amino-2-methylnaphthalene, 2,3-dimethylaniline, 2,4-dimethylaniline, 2,5-dimethylaniline, 3,4-dimethyl Examples thereof include aniline, 4-ethylaniline, 4-ethynylaniline, 4-isopropylaniline, 4- (methylthio) aniline, N, N-dimethyl-1,4-phenylenediamine and the like.

Examples of the phenolic hydroxyl group-containing monoamine represented by the above formula (12) include 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o-cresol, and 4-amino-2. , 3-Xylenol, 4-amino-2,5-xylenol, 4-amino-2,6-xylenol, 4-amino-1-naphthol, 5-amino-2-naphthol, 6-amino-1-naphthol, 4 -Amino-2,6-diphenylphenol and the like can be mentioned. Of these, 4-amino-o-cresol and 5-amino-o-cresol are preferable because they are excellent in availability and storage stability, and a high glass transition temperature can be obtained after curing.

When the imide oligomer is produced by the above-mentioned production method, the imide oligomer is a plurality of imide oligomers having a structure represented by the above formula (1-1) or a structure represented by the above formula (1-2). It is obtained as a mixture of a plurality of types of imide oligomers having the above and each raw material (imide oligomer composition). When the imide oligomer composition has an imidization ratio of 70% or more, a cured product having superior mechanical strength and long-term heat resistance at high temperatures can be obtained when used as a curing agent.
The preferable lower limit of the imidization ratio of the imide oligomer composition is 75%, and the more preferable lower limit is 80%. Further, although there is no particular preferable upper limit of the imidization ratio of the imide oligomer composition, the practical upper limit is 98%.
The above "imidization rate" was measured by a total reflection measurement method (ATR method) using a Fourier transform infrared spectrophotometer (FT-IR), and was derived from the carbonyl group of amic acid at 1660 cm ^-1. It can be derived from the peak absorbance area in the vicinity by the following formula. Examples of the Fourier transform infrared spectrophotometer include UMA600 (manufactured by Agilent Technologies) and the like. The "peak absorbance area of the amic acid oligomer" in the following formula is determined by reacting the acid dianhydride with a diamine or a phenolic hydroxyl group-containing monoamine, and then removing the solvent by evaporation or the like without performing an imidization step. It is the absorbance area of the amic acid oligomer obtained by the above.
Imidization rate (%) = 100 × (1- (peak absorbance area after imidization) / (peak absorbance area of amic acid oligomer)))

From the viewpoint of solubility when the imide oligomer composition is used as a curing agent in a curable resin composition, it is preferable to dissolve 3 g or more of the imide oligomer composition in 10 g of tetrahydrofuran at 25 ° C.

Further, the imide oligomer has an imide skeleton in the main chain, an aliphatic diamine residue which may be substituted and / or an aliphatic triamine residue which may be substituted, and a crosslinkable functional group at the terminal. An imide oligomer having an imide oligomer (hereinafter, also referred to as "oliphatic diamine residue and / or aliphatic triamine residue-containing imide oligomer") is preferable. Since the aliphatic diamine residue and / or the aliphatic triamine residue-containing imide oligomer has the aliphatic diamine residue and / or the aliphatic triamine residue, the curable resin composition obtained can be obtained before curing. Flexibility and workability, as well as tackability at room temperature can be improved.

The preferable lower limit of the content of the imide oligomer in 100 parts by weight of the total of the curable resin and the curing agent (further curing accelerator when the curing accelerator described later is contained) is 20 parts by weight, and the preferable upper limit is 80 parts by weight. Is. When the content of the imide oligomer is in this range, the obtained curable resin composition becomes more excellent in flexibility and processability before curing and heat resistance after curing. The more preferable lower limit of the content of the imide oligomer is 25 parts by weight, and the more preferable upper limit is 75 parts by weight.
When the imide oligomer according to the present invention is contained in the above-mentioned imide oligomer composition, the content of the imide oligomer is the imide oligomer composition (when another imide oligomer is used in combination, the imide oligomer is used). It means the content of the composition and other imide oligomers).

The curable resin composition of the present invention preferably contains a polymer compound. When a flow conditioner composed of inorganic particles or the like is used to adjust the viscosity of the curable resin composition within the above range, it may be difficult to set the thixotropic index within the above range. In addition, it may be difficult to keep the initial adhesive force of the cured product on the silicon chip and the adhesive force of the cured product on the silicon chip after storage at 150 ° C. for 100 hours within the above-mentioned range. On the other hand, by using the above-mentioned polymer compound, it becomes easier to keep the viscosity and the thixotropic index within the above-mentioned range while maintaining the adhesiveness and long-term heat resistance of the cured product.

The preferable lower limit of the number average molecular weight of the polymer compound is 10,000, and the preferable upper limit is 80,000. When the number average molecular weight of the polymer compound is in this range, the viscosity and the thixotropic index should be in the above range while maintaining the adhesiveness and long-term heat resistance of the cured product of the obtained curable resin composition. Will be easier. The more preferable lower limit of the number average molecular weight of the polymer compound is 12000, and the upper limit is 70,000.

Examples of the polymer compound include polyimide, polyamideimide, bismaleimide, phenoxy resin, polyester and the like. Of these, polyimide and phenoxy resin are preferable, and polyimide is more preferable, from the viewpoint of heat resistance.
The polymer compound may be used alone or in combination of two or more.

Regarding the content of the polymer compound, the preferable lower limit is 1 part by weight, and the preferable upper limit is 1 part by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (in the case of further containing the curing accelerator described later, the curing accelerator). Is 25 parts by weight. When the content of the polymer compound is in this range, the viscosity and the thixotropic index can be set in the above range while maintaining the adhesiveness and long-term heat resistance of the cured product of the obtained curable resin composition. It will be easier. The more preferable lower limit of the content of the polymer compound is 5 parts by weight, and the more preferable upper limit is 20 parts by weight.

The curable resin composition of the present invention preferably contains a curing accelerator. By containing the above-mentioned curing accelerator, the curing time can be shortened and the productivity can be improved.

Examples of the curing accelerator include an imidazole-based curing accelerator, a hydrazide-based curing accelerator, a tertiary amine-based curing accelerator, a phosphine-based curing accelerator, a photobase generator, a sulfonium salt-based curing accelerator, and the like. .. Among them, at least one selected from the group consisting of an imidazole compound, a hydrazide compound, and a phosphorus-based compound is preferable from the viewpoint of storage stability and curability. Further, the curing accelerator may be a microcapsule type curing accelerator containing at least one selected from the group consisting of an imidazole compound, a hydrazide compound, and a phosphorus-based compound.
The curing accelerator may be used alone or in combination of two or more.

The preferable upper limit of the content of the curing accelerator with respect to a total of 100 parts by weight of the curing resin, the curing agent and the curing accelerator is 1.5 parts by weight. When the content of the curing accelerator is 1.5 parts by weight or less, the obtained curable resin composition becomes more excellent in storage stability. A more preferable upper limit of the content of the curing accelerator is 1.0 part by weight.
Further, the preferable lower limit of the content of the curing accelerator with respect to a total of 100 parts by weight of the curing resin, the curing agent and the curing accelerator is 0.4 parts by weight. When the content of the curing accelerator is 0.4 parts by weight or more, the effect of shortening the curing time is more excellent. A more preferable lower limit of the content of the curing accelerator is 0.5 parts by weight.

The curable resin composition of the present invention may contain an inorganic filler for the purpose of improving moisture absorption / reflow resistance and plating resistance as long as the object of the present invention is not impaired.

The inorganic filler is preferably at least one of silica and barium sulfate. By containing at least one of silica and barium sulfate as the inorganic filler, the curable resin composition of the present invention is excellent in moisture absorption reflow resistance, plating resistance, and processability.

Examples of the inorganic filler other than the silica and barium sulfate include alumina, aluminum nitride, boron nitride, silicon nitride, glass powder, glass frit, glass fiber, carbon fiber, and an inorganic ion exchanger.

The inorganic filler may be used alone or in combination of two or more.
Further, as the inorganic filler, one having an average particle size of 50 nm or more and less than 4 μm is preferably used.

The content of the inorganic filler is preferably 200 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (further, if the curing accelerator is contained, the curing accelerator). be. When the content of the inorganic filler is in this range, the cured product of the obtained curable resin composition is superior in moisture absorption reflow resistance and plating resistance while maintaining excellent tackiness and the like. A more preferable upper limit of the content of the inorganic filler is 150 parts by weight.

The curable resin composition of the present invention may contain a flow conditioner.
Examples of the flow conditioner include fumed silica such as Aerosil and layered silicate.
The flow adjusting agent may be used alone or in combination of two or more.
Further, as the flow adjusting agent, one having an average particle size of less than 100 nm is preferably used.

The preferable upper limit of the content of the flow adjusting agent is 2.0 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (further, if the curing accelerator is contained, the curing accelerator). When the content of the flow adjusting agent is 2.0 parts by weight or less, the obtained curable resin composition is more excellent in the applicability to the adherend in a short time. A more preferable upper limit of the content of the flow adjusting agent is 1.5 parts by weight.
Further, from the viewpoint of shape retention after coating, there is no particular preferable lower limit of the content of the flow adjusting agent, but the practical lower limit is 0 parts by weight.

The curable resin composition of the present invention may contain an organic filler for the purpose of stress relaxation, toughness imparting, etc., as long as the object of the present invention is not impaired.
Examples of the organic filler include silicone rubber particles, acrylic rubber particles, urethane rubber particles, polyamide particles, polyamide-imide particles, polyimide particles, benzoguanamine particles, and core-shell particles thereof. Of these, polyamide particles, polyamide-imide particles, and polyimide particles are preferable.
The organic filler may be used alone or in combination of two or more.

The content of the organic filler is preferably 200 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (further, if the curing accelerator is contained, the curing accelerator). be. When the content of the organic filler is in this range, the cured product of the obtained curable resin composition becomes more excellent in toughness and the like while maintaining excellent adhesiveness and the like. A more preferable upper limit of the content of the organic filler is 150 parts by weight.

The curable resin composition of the present invention may contain a flame retardant as long as the object of the present invention is not impaired.
Examples of the flame retardant include metal hydrates such as boehmite type aluminum hydroxide, aluminum hydroxide and magnesium hydroxide, halogen compounds, phosphorus compounds, nitrogen compounds and the like. Of these, boehmite-type aluminum hydroxide is preferable.
The flame retardant may be used alone or in combination of two or more.

The content of the flame retardant is preferably 200 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (further, if the curing accelerator is contained, the curing accelerator). .. When the content of the flame retardant is in this range, the obtained curable resin composition has excellent flame retardancy while maintaining excellent adhesiveness and the like. A more preferable upper limit of the content of the flame retardant is 150 parts by weight.

The curable resin composition of the present invention may contain a reactive diluent as long as the object of the present invention is not impaired.
As the reactive diluent, a reactive diluent having two or more reactive functional groups in one molecule is preferable from the viewpoint of adhesive reliability.

The curable resin composition of the present invention preferably contains a solvent.
As the solvent, a solvent having a boiling point of less than 200 ° C. is preferable from the viewpoint of coatability, storage stability and the like.
Examples of the solvent having a boiling point of less than 200 ° C. include alcohol-based solvents, ketone-based solvents, ester-based solvents, hydrocarbon-based solvents, halogen-based solvents, ether-based solvents, nitrogen-containing solvents and the like.
Examples of the alcohol-based solvent include methanol, ethanol, isopropyl alcohol, normal propyl alcohol, isobutyl alcohol, normal butyl alcohol, tertiary butyl alcohol, 2-ethielhexanol and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, diacetone alcohol and the like. Of these, annon-based solvents are preferable.
Examples of the ester-based solvent include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methoxybutyl acetate, amyl acetate, normal propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, butyl lactate and the like.
Examples of the hydrocarbon solvent include benzene, toluene, xylene, normal hexane, isohexane, cyclohexane, methylcyclohexane, ethylcyclohexane, isooctane, normal decane, normal heptane and the like.
Examples of the halogen-based solvent include dichloromethane, chloroform, trichlorethylene and the like.
Examples of the ether-based solvent include diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, diisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether acetate. , Propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol monotersial butyl ether, propylene glycol monomethyl ether propionate, 3-methoxybutanol, diethylene glycol dimethyl ether, anisole, 4-methylanisole and the like. Be done.
Examples of the nitrogen-containing solvent include acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide and the like.
Among them, from the viewpoint of handleability and solubility of imide oligomers, a ketone solvent having a boiling point of 60 ° C. or higher and lower than 200 ° C., an ester solvent having a boiling point of 60 ° C. or higher and lower than 200 ° C., and a boiling point of 60 ° C. or higher and 200 ° C. At least one selected from the group consisting of ether solvents below ° C is preferred. Examples of such a solvent include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, isobutyl acetate, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, cyclohexanone, methylcyclohexanone, diethylene glycol dimethyl ether, anisole and the like.
A particularly preferable solvent has a boiling point of 100 ° C. or higher and lower than 200 ° C. When the boiling point of the solvent is in this range, the coatability by the spin coating method is improved.
The curable resin composition of the present invention may contain a solvent having a boiling point of 200 ° C. or higher.
Examples of the solvent having a boiling point of 200 ° C. or higher include a nitrogen-containing solvent.
Examples of the nitrogen-containing solvent include N-methyl-2-pyrrolidone.
The above "boiling point" means a value measured under the condition of 101 kPa or a value converted to 101 kPa in a boiling point conversion chart or the like.

In the curable resin composition of the present invention, the preferable lower limit of the solid content concentration is 40% by weight, and the preferable upper limit is 70% by weight. When the solid content concentration is in this range, the applicability by the spin coating method is improved. The more preferable lower limit of the solid content concentration is 45% by weight, and the more preferable upper limit is 65% by weight.
From the viewpoint of storage stability, the preferable lower limit of the solid content concentration is 40% by weight, and the preferable upper limit is 60% by weight.
The term "solid content" means a component other than the solvent when the curable resin composition contains the solvent.

The curable resin composition of the present invention may further contain additives such as a coupling agent, a dispersant, a storage stabilizer, an antibleeding agent, a flux agent, and a leveling agent.

Examples of the method for producing the curable resin composition of the present invention include a method of mixing a curable resin, a curing agent, a polymer compound, a curing accelerator, and the like using a mixer. Examples of the mixer include a homodisper, a universal mixer, a Banbury mixer, a kneader and the like.

The curable resin composition of the present invention can be used for a wide range of applications, but can be suitably used for electronic material applications in which high long-term heat resistance is particularly required. For example, it can be used as a diagnostic agent in aviation and in-vehicle electric control unit applications, and in power device applications using SiC and GaN. Further, for example, an adhesive for a printed wiring board, an adhesive for a coverlay of a flexible printed circuit board, a copper-clad laminate, an adhesive for semiconductor bonding, an interlayer insulating material, a prepreg, an adhesive for an LED, and an adhesive for a structural material. , Can also be used as an adhesive for power overlay packages.
Among them, it is preferably used for adhesive applications. An adhesive containing the curable resin composition of the present invention is also one of the present inventions. An adhesive varnish containing a solvent in the curable resin composition of the present invention is also one of the present inventions.

By applying the curable resin composition of the present invention on a substrate and drying it, a curable resin composition film composed of the curable resin composition of the present invention can be obtained, and the curable resin can be obtained. The composition film can be cured to obtain a cured product. The curable resin film can be suitably used as an adhesive film. An adhesive film having an adhesive layer containing the curable resin composition of the present invention is also one of the present inventions.
The cured product of the curable resin composition of the present invention is also one of the present inventions.

According to the present invention, it is possible to provide a curable resin composition having excellent coatability by a spin coating method, adhesiveness of a cured product, and long-term heat resistance. Further, according to the present invention, it is possible to provide an adhesive, an adhesive varnish, and an adhesive film using the curable resin composition, and a cured product of the curable resin composition.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Preparation of imide oligomer composition)
4,4'-(4,4'-isopropyridendiphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) 104 parts by weight N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "NMP") 300 weight Dissolved in the part. To the obtained solution, add a solution obtained by diluting 28 parts by weight of preamine 1074 (manufactured by Croda), which is a diamine diamine, with 100 parts by weight of N-methylpyrrolidone, and stir at 25 ° C. for 2 hours to react to make an amic acid oligomer solution. Got After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain an imide oligomer composition (imidization ratio 93%).
The obtained imide oligomer composition is an aliphatic diamine residue having a structure represented by the above formula (4-1) or (4-3) by ^{1 H-NMR, GPC, and FT-IR analysis.} It was confirmed that the group-containing imide oligomer (A is a 4,4'-(4,4'-isopropyridenediphenoxy) diphthalic acid anhydride residue and B is a diamine diamine residue) is contained. The number average molecular weight of the imide oligomer composition was 2200.

(Preparation of Synthesis Example 1 (Polyimide Resin Solution A))
52.3 parts by weight of 4,4'-oxydiphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 200 parts by weight of cyclohexanone were charged in a reaction vessel equipped with a stirrer, a water divider, and a nitrogen gas introduction pipe. Dissolved. A mixed solution of 56.1 parts by weight of the polyimide diamine Priamine (manufactured by Croda) and 55.0 parts by weight of cyclohexanone was added dropwise to the obtained solution, and then an imidization reaction was carried out at 150 ° C. for 8 hours. A polyimide resin solution A was obtained. The solid content concentration of the obtained polyimide resin solution A was 30% by weight, and the number average molecular weight of the polyimide resin was 23000.

(Preparation of Synthesis Example 2 (Polyimide Resin Solution B))
4,4'-(4,4'-isopropyridendiphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) 54.6 weight in a reaction vessel equipped with a stirrer, a water divider, and a nitrogen gas introduction tube. A portion and 200 parts by weight of cyclohexanone were charged and dissolved. A mixed solution of 56.1 parts by weight of the polyimide diamine Priamine (manufactured by Croda) and 55.0 parts by weight of cyclohexanone was added dropwise to the obtained solution, and then an imidization reaction was carried out at 150 ° C. for 8 hours. A polyimide resin solution B was obtained. The solid content concentration of the obtained polyimide resin solution B was 30% by weight, and the number average molecular weight of the polyimide resin was 25,000.

(Examples 1 to 9, Comparative Examples 1 to 4)
Each material was stirred and mixed according to the compounding ratios shown in Tables 1 and 2, and the curable resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4 were prepared.

(Viscosity at 25 ° C and Chixotropic Index)
For each of the obtained curable resin compositions, within 60 minutes after production, a CP1 type cone plate was used at 25 ° C. using an E-type viscometer (“VISCOMETER TV-22” manufactured by Toki Sangyo Co., Ltd.). The viscosity under the condition of 10 rpm was measured. Further, each of the curable resin compositions obtained in Examples 6 to 9 and Comparative Examples 3 and 4 was stored at 25 ° C. for 8 days after production, and then an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “ Using VISCOMETER TV-22 ”), the viscosity was measured on a CP1 type cone plate under the conditions of 25 ° C. and 10 rpm.
Further, in the same manner, the viscosity of each curable resin composition within 60 minutes after production was measured under the conditions of 25 ° C. and 1.0 rpm and 25 ° C. and 10 rpm, and a thixotropic index was derived.
The results are shown in Tables 1 and 2.

(Initial adhesive strength of cured product to silicon chip)
Each of the obtained curable resin compositions was applied to a polyimide substrate having a length of 10 mm and a width of 10 mm, and silicon chips having a length of 3 mm, a width of 3 mm and a thickness of 0.3 mm were laminated. Then, the curable resin composition was cured by heating at 190 ° C. for 1 hour to obtain a test piece. The obtained test piece was measured for die shear strength at 25 ° C. at a speed of 100 μm / s using a die shear tester, and the obtained die shear strength was used as the initial adhesive force to the silicon chip of the cured product. As the polyimide, Kapton 200H (manufactured by Toray Industries, Inc., surface roughness 0.03 to 0.07 μm) is used, and as the silicon chip, a silicon chip manufactured by Global Wafer Co., Ltd. (surface roughness 0.5 to 1) is used. 0.0 nm) was used, and as the die share tester, DAGE4000 (manufactured by Toray Industries, Inc.) was used. The results are shown in Tables 1 and 2.

(Adhesive strength of cured product to silicon chips after storage at 150 ° C for 100 hours)
The test piece obtained in the same manner as the above "(Initial adhesive strength of the cured product to the silicon chip)" was stored in an oven at 150 ° C. for 100 hours. Next, for the test piece after storage, the die shear strength at 25 ° C. was measured at a speed of 100 μm / s using a die shear tester, and the obtained die shear strength was stored at 150 ° C. for 100 hours, and then the cured product silicon was obtained. Adhesive strength to the chip. The results are shown in Tables 1 and 2.

<Evaluation>
The following evaluations were performed on each of the curable resin compositions obtained in Examples and Comparative Examples. The results are shown in Tables 1 and 2.

(Applicability by spin coating method (coating uniformity))
2.0 mL of each of the obtained curable resin compositions was dropped onto a silicon wafer having a thickness of 4 inches and a thickness of 0.3 mm, and the mixture was rotated at 25 ° C. and 1300 rpm for 10 seconds using a spin coater to make silicon. The curable resin composition was applied onto the wafer. As the spin coater, SPINCOATER 1HD7 (manufactured by Mikasa) was used.
The obtained curable resin composition film was dried at 90 ° C. for 10 minutes, and then the thickness of the curable resin composition film was measured with a constant pressure thickness measuring device (manufactured by Mitutoyo Co., Ltd.). When the difference in thickness between the center and the edge of the coating film is 1 μm or less, it is “◎”, when it is more than 1 μm and 5 μm or less, it is “○”, and when it is more than 5 μm and 15 μm or less, it is “△”. , The case where it exceeded 15 μm was regarded as “x”, and the coatability (coating film uniformity) by the spin coating method was evaluated.

(Long-term heat resistance)
Each of the curable resin compositions obtained in Examples and Comparative Examples was coated on a base material PET film so as to have a thickness of about 20 μm, and dried to obtain a curable resin composition on the base material PET film. A film was made. The base material PET film is peeled off from the obtained curable resin composition film, a polyimide film having a thickness of 20 μm (manufactured by Toray DuPont, “Kapton V”) is laminated on both sides, and heated at 190 ° C. for 1 hour. After curing, heat treatment was performed at 175 ° C. for 1000 hours. A laminate of the cured product of the curable resin composition after the heat treatment and the polyimide film was placed along a semicircular shape on a cylinder having a diameter of 5 mm or 3 mm at room temperature, and then the state of the laminate was visually observed.
No cracks or cracks were found even when the laminate was placed along a semicircular shape on a 3 mm cylinder. No cracks or cracks were found even when the laminate was placed along a semicircular shape on a 5 mm cylinder. However, if cracks or cracks are found along a semicircle on a 3 mm cylinder, it is marked as "△", and if cracks or cracks are found along a semicircle on a 5 mm cylinder, it is marked as "x". The long-term heat resistance was evaluated.

According to the present invention, it is possible to provide a curable resin composition having excellent coatability by a spin coating method, adhesiveness of a cured product, and long-term heat resistance. Further, according to the present invention, it is possible to provide an adhesive, an adhesive varnish, and an adhesive film using the curable resin composition, and a cured product of the curable resin composition.

Claims (17)

1. The viscosity at 25 ° C. is 200 mPa · s or more and 600 mPa · s or less.
   The thixotropic index at 25 ° C is 2.0 or less,
   The initial adhesive strength of the cured product to the silicon chip is 3 MPa or more, and
   A curable resin composition characterized in that the adhesive strength of the cured product to a silicon chip after storage at 150 ° C. for 100 hours is 2 MPa or more.
2. The curable resin composition according to claim 1, wherein the viscosity after storage at 25 ° C. for 8 days is 2.0 times or less the initial viscosity.
3. The curable resin composition according to claim 1 or 2, which contains a curable resin and a curing agent.
4. The curable resin composition according to claim 3, wherein the curable resin contains an epoxy resin.
5. The curable resin composition according to claim 3 or 4, wherein the curing agent contains an imide oligomer.
6. The curable resin composition according to claim 5, wherein the imide oligomer has a structure represented by the following formula (1-1) or the following formula (1-2).
   

   

   In formulas (1-1) and (1-2), A is an acid dianhydride residue, and in formula (1-1), B is an aliphatic diamine residue or an aromatic diamine residue. Yes, in formula (1-2), Ar is a optionally substituted divalent aromatic group.
7. Contains a curing accelerator,
   The curing according to claim 1, 2, 3, 4, 5 or 6, wherein the content of the curing accelerator in a total of 100 parts by weight of the curable resin, the curing agent and the curing accelerator is 1.5 parts by weight or less. Sex resin composition.
8. The curable resin composition according to claim 7, wherein the curing accelerator is at least one selected from the group consisting of an imidazole compound, a hydrazide compound, and a phosphorus-based compound.
9. The curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7 or 8, which contains a polymer compound.
10. The curable resin composition according to claim 9, wherein the polymer compound contains polyimide.
11. Contains a flow regulator,
    Claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or the content of the flow adjusting agent in 100 parts by weight of the curable resin and the curing agent is 2.0 parts by weight or less. 10. The curable resin composition according to 10.
12. At least one selected from the group consisting of a ketone solvent having a boiling point of 60 ° C. or higher and lower than 200 ° C., an ester solvent having a boiling point of 60 ° C. or higher and lower than 200 ° C., and an ether solvent having a boiling point of 60 ° C. or higher and lower than 200 ° C. The curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11.
13. The curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein the solid content concentration is 40% by weight or more and 70% by weight or less.
14. An adhesive comprising the curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13.
15. The adhesive varnish containing a solvent in the curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13.
16. An adhesive film having an adhesive layer containing the curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13.
17. The cured product of the curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13.