阅读说明：本技术 树脂组合物 (Resin composition ) 是由 田渕聪宽 稻垣达也 于 2019-09-27 设计创作，主要内容包括：本发明涉及一种含有环氧树脂、特定的偶联剂以及无机填料的树脂组合物。(The present invention relates to a resin composition containing an epoxy resin, a specific coupling agent and an inorganic filler.)

1. A resin composition comprising an epoxy resin, a coupling agent and an inorganic filler,

the coupling agent is at least 1 selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3);

wherein, in the general formula (1), R¹、R²And R³Are respectively CH₃Or C₂H₅；

Wherein, in the general formula (2), R¹、R²And R³Are respectively CH₃Or C₂H₅；

Wherein in the general formula (3), n is an integer of 13-19, R⁴Each independently an alkyl group or an alkyl ether group having 8 to 12 carbon atoms, wherein the alkyl moiety is a linear saturated hydrocarbon or a branched hydrocarbon containing an unsaturated bond.

2. The resin composition according to claim 1, wherein the coupling agent is a compound represented by general formula (3).

3. The resin composition according to claim 1 or 2, wherein the inorganic filler is a boron nitride filler.

Technical Field

The present invention relates to a resin composition.

Background

Conventionally, in the field of electronic products, a resin composition containing an epoxy resin and an inorganic filler has been used.

Patent document 1 below discloses that a cured product obtained by curing a resin composition containing an epoxy resin and an inorganic filler is used as a heat sink.

Such a heat sink contains a relatively large amount of an inorganic filler such as a boron nitride filler, and has heat dissipation properties.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2010-94887

Disclosure of Invention

Problems to be solved by the invention

However, the resin composition described in patent document 1 has a problem that it does not always ensure sufficient adhesive strength to an adherend after being cured into a cured product because it contains a particulate inorganic filler.

Accordingly, an object of the present invention is to provide a resin composition which can sufficiently secure adhesive strength with an adherend when the resin composition is cured into a cured product.

Means for solving the problems

The resin composition of the present invention is a resin composition containing an epoxy resin, a coupling agent and an inorganic filler,

the coupling agent is at least 1 selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3).

(wherein, in the general formula (1), R¹、R²And R³Are respectively CH₃Or C₂H₅。)

(wherein, in the general formula (2), R¹、R²And R³Are respectively CH₃Or C₂H₅。)

(wherein, in the general formula (3), n is an integer of 13 to 19, R⁴Each independently an alkyl group or an alkyl ether group having 8 to 12 carbon atoms, wherein the alkyl moiety is a linear saturated hydrocarbon or a branched hydrocarbon containing an unsaturated bond. )

Detailed Description

One embodiment of the present invention will be described below.

The resin composition of the present embodiment contains components that will ultimately constitute a cured product. In other words, the resin composition of the present embodiment contains a polymerizable component that becomes a cured resin by polymerization.

In addition, the resin composition of the present embodiment contains an inorganic filler so that a cured product after curing has good thermal conductivity.

Further, the resin composition of the present embodiment contains a coupling agent which serves to connect the polymerizable component and the inorganic filler.

The resin composition of the present embodiment may contain additives generally used as plastic compounding chemicals within a range not to impair the effects of the present invention.

In the resin composition of the present embodiment, the content ratio of the polymerizable component is preferably 10% by mass or more and 70% by mass or less, and more preferably 30% by mass or more and 40% by mass or less.

The cured product obtained by curing the resin composition of the present embodiment preferably contains 10 vol% or more and 60 vol% or less of the inorganic filler, more preferably 40 vol% or more and 50 vol% or less, when the solid content is 100 vol%.

In addition, from the viewpoint that the content ratio of the inorganic filler in the cured product can be easily controlled within the above range, the resin composition of the present embodiment preferably contains the inorganic filler in an amount of 30 parts by mass or more and 90 parts by mass or less, and more preferably 60 parts by mass or more and 70 parts by mass or less, based on 100 parts by mass of the polymerizable component.

The resin composition of the present embodiment contains the coupling agent in an amount of 0.01 to 0.03 parts by mass based on 100 parts by mass of the inorganic filler.

Further, the resin composition of the present embodiment preferably contains the additive in an amount of 0.005 parts by mass or more and 0.05 parts by mass or less, more preferably 0.01 parts by mass or more and 0.03 parts by mass or less, based on 100 parts by mass of the inorganic filler.

The resin composition of the present embodiment contains an epoxy resin and a curing agent for the epoxy resin as the polymerizable component. In the present embodiment, the epoxy resin is cured together with a curing agent for the epoxy resin to form a cured resin.

The total amount of the epoxy resin and the curing agent for the epoxy resin is preferably 80 mass% or more and 100 mass% or less, and more preferably 90 mass% or more and 100 mass% or less in the polymerizable component.

The ratio of the curing agent equivalent of the epoxy resin to the epoxy resin equivalent is preferably 1/2 or more and 2/1 or less, and more preferably 2/3 or more and 3/2 or less.

The epoxy resin has a plurality of epoxy groups in a molecular structure. Examples of the epoxy resin include: bisphenol a type epoxy resins, novolac type epoxy resins, cyclic aliphatic type epoxy resins, long chain aliphatic type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, and the like.

Examples of the curing agent for the epoxy resin include amine-based curing agents, phenol-based curing agents, and acid anhydrides.

Examples of the amine-based curing agent include diaminodiphenyl sulfone, dicyandiamide, diaminodiphenylmethane, triethylenetetramine, and the like.

Examples of the phenol-based curing agent include phenol novolak resins, aralkyl-type phenol resins, dicyclopentadiene-modified phenol resins, naphthalene-type phenol resins, and bisphenol-type phenol resins.

Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, and maleic anhydride.

Examples of the inorganic filler include a boron nitride filler, an aluminum nitride filler, a silicon nitride filler, a gallium nitride filler, an alumina filler, a silicon carbide filler, a silica filler, a magnesium oxide filler, and a diamond filler.

The resin composition of the present embodiment preferably contains a boron nitride filler having excellent thermal conductivity as the inorganic filler. The boron nitride filler has excellent thermal conductivity, but has few surface functional groups (OH and the like) involved in polymerization. Therefore, in the resin composition containing a boron nitride filler and not containing the coupling agent, since the surface functional group of the boron nitride filler is small, it is difficult to improve the affinity between the polymerizable component and the boron nitride filler.

However, the resin composition of the present embodiment contains the coupling agent. The coupling agent contains a functional group having affinity with the surface functional group of the inorganic filler and a functional group having affinity with the functional group of the polymerizable component, as described later. Therefore, even when the resin composition contains a boron nitride filler having a small surface functional group, the coupling agent can serve to connect the polymerizable component and the boron nitride filler. As a result, when the resin composition of the present embodiment becomes a cured product, the cohesive failure strength of the cured product increases.

Thus, when a boron nitride filler having excellent thermal conductivity is contained as the inorganic filler, the resin composition of the present embodiment can improve the thermal conductivity and cohesive failure strength of a cured product when the cured product is produced.

In addition, the thermal conductivity and cohesive failure strength of a cured product when the cured product is produced can be adjusted by changing the content of the boron nitride filler.

It is important that the resin composition of the present embodiment contains at least 1 kind selected from the group consisting of a silane coupling agent of the following general formula (1), a silane coupling agent of the following general formula (2), and a titanate coupling agent of the following general formula (3) as the coupling agent.

Wherein, in the following general formulae (1) and (2), R¹、R²And R³Are respectively CH₃Or C₂H₅. In the general formula (3), n is an integer of 13-19, R⁴Each independently an alkyl group or an alkyl ether group having 8 to 12 carbon atoms, wherein the alkyl moiety is a linear saturated hydrocarbon or a branched hydrocarbon containing an unsaturated bond.

As the silane coupling agent and the titanate coupling agent, commercially available ones can be used.

In the above general formula (3), R⁴May have quaternary carbon atoms and may have an alkyl ether group and may have 2 ethylenically unsaturated groups. R⁴May be 12. In the above general formula (3), n is preferably 13 or 19.

In the resin composition of the present embodiment, at least a part of the coupling agent is hydrolyzed to react with the functional group on the surface of the inorganic filler, thereby surface-treating the inorganic filler.

In the silane coupling agents of the general formula (1) and the general formula (2), the functional group (OR) at one end side of the carbon chain¹Radical, OR²Radical and OR³Group) has affinity with the surface functional group of the aforementioned inorganic filler. The functional group on the other end side of the carbon chain (methacryloyl group in the formula (1) and vinyl group in the formula (2)) has affinity with the functional group of the polymerizable component. Thus, in the resin composition of the present embodiment, the silane coupling agent of the formula (1) or (2) can function to connect the polymerizable component and the inorganic filler. In detailIn the silane coupling agent of the general formula (1) or the general formula (2), the functional group on one end side of the carbon chain is disposed in the vicinity of the surface of the inorganic filler, and the functional group on the other end side of the carbon chain is disposed in the vicinity of the functional group of the polymerizable component, whereby the polymerizable component and the inorganic filler are linked by the silane coupling agent.

More specifically, the resin composition of the present embodiment contains a silane coupling agent having a long linear portion of a carbon chain. The straight chain portion of the carbon chain is a portion in which a silicon atom and a methacryloyl group are bonded in the above general formula (1), and a portion in which a silicon atom and a vinyl group are bonded in the above formula (2).

By containing such a silane coupling agent, the distance from one end side to the other end side of the carbon chain of the silane coupling agent disposed in the vicinity of the surface of the inorganic filler can be extended. Therefore, the space in which the functional group of the polymerizable component can approach the functional group on the other end side of the carbon chain can be further enlarged as compared with the case where a coupling agent having a short length from one end side to the other end side of the carbon chain is contained. Therefore, the functional group of the polymerizable component and the functional group on the other end side of the carbon chain can be more reliably brought closer. This can more reliably achieve the function of connecting the inorganic filler and the polymerizable component.

This improves the cohesive failure strength of the cured product after curing.

Further, by using the silane coupling agent having a long linear portion of the carbon chain as in the above general formulae (1) and (2), the distance from one end side to the other end side of the carbon chain of the silane coupling agent can be extended as described above. Therefore, the distance (free distance) between the polymerizable component and the inorganic filler can be increased as compared with the case where a silane coupling agent having a short length from one end side to the other end side of the carbon chain is contained.

The titanate coupling agent of the above general formula (3) can also exert the same effects as described above. Further, the titanate coupling agent of the general formula (3) has P — OH groups having an excellent affinity with metals in the molecule, and thus the cured product after curing has a better adhesion to a metal-containing adherend.

The silane coupling agent of the general formula (1) is preferably a silane coupling agent of the following formula (1)'; the silane coupling agent of the general formula (2) is preferably a silane coupling agent of the following formula (2)'.

The titanate coupling agent of the general formula (3) is preferably at least one of the titanate coupling agents of the following formula (3)' and the following formula (3) ". In the following formula (3)' and the following formula (3) ", n may be 13 or 19.

The applicant of the present application speculates that the resin composition of the present embodiment is considered to have the above-described characteristics, and therefore, when the resin composition is changed into a cured product, the peel strength between the cured product and an adherend is improved.

On the other hand, although the silane coupling agent has a long linear portion of the carbon chain, the silane coupling agent having a structure represented by the following formula (4) is not preferable. In other words, the resin composition of the present embodiment preferably does not contain a silane coupling agent having hydrogen (H) bonded to nitrogen (N) in the molecule.

(wherein, in the above formula (4), R¹、R²And R³Are respectively CH₃Or C₂H₅。)

When the resin composition contains a substance having a structure represented by the general formula (4) as the silane coupling agent, the viscosity of the resin composition becomes extremely high (the resin composition becomes excessively viscous) at a temperature around room temperature (for example, 25 ℃). The reason for this is considered to be that the functional group (amino group in the general formula (4)) on the other end side of the carbon chain of the silane coupling agent functions as a curing agent for the polymerizable component at a temperature around room temperature, and the polymerizable component starts to cure. As described above, when the viscosity of the resin composition becomes extremely high, it is difficult to mold the resin composition into a molded article having a predetermined shape (for example, a sheet shape), which is not preferable.

Therefore, it is important to use, as the coupling agent, a coupling agent in which the linear portion of the carbon chain is long and which hardly functions as a curing agent of the polymerizable component at a temperature around room temperature.

Examples of the additive include a curing accelerator for accelerating a curing reaction between the epoxy resin and a curing agent for the epoxy resin, and further include a dispersant, a thickener, an antioxidant, a processing aid, a stabilizer, an antifoaming agent, a flame retardant, a thickener, a pigment, and the like.

Examples of the curing accelerator include Tetraphenylphosphonium tetraphenylboron (Tetraphenylphosphonium tetraphenylboron), imidazoles, Triphenylphosphine (TPP), and amine-based curing accelerators. Examples of the amine-based curing accelerator include boron trifluoride monoethylamine.

The resin composition of the present embodiment preferably contains the curing accelerator in an amount of 0.5 to 1.5 parts by mass, more preferably 0.5 to 1.0 part by mass, based on 100 parts by mass of the total amount of the epoxy resin and the curing agent for the epoxy resin.

The resin composition of the present embodiment may be in a state in which the curing reaction has progressed to some extent but the resin composition is not completely cured. In other words, a part of the resin composition may be in a state of undergoing a curing reaction. For example, the resin composition may be coated in a sheet form in a state having fluidity and then partially cured. The resin composition of the present embodiment contains the epoxy resin, the specific coupling agent, and the inorganic filler even in a state in which the curing reaction is partially performed.

The material of the adherend is preferably metal. In detail, a metal containing copper or aluminum is preferable.

The resin composition of the present embodiment can be cured in a sheet-like state and used for a metal base circuit board. The metal base circuit board is formed by, for example, bonding a circuit layer to a sheet-like cured product. Since the metal-base circuit board formed by this structure has the sheet-like cured product, the metal-base circuit board is also excellent in thermal conductivity.

The resin composition of the present embodiment can be cured in a sheet-like state and used for, for example, a power module. The power supply module may be constructed, for example, in the following manner: a semiconductor chip, a power supply IC, and other heating elements are mounted on the circuit layer of the metal base circuit board, and these elements are temporarily encapsulated with silicone gel, and then resin-molded on the silicone gel. Since the power module formed by this structure has the sheet-like cured product, the power module is also a product having excellent thermal conductivity.

The resin composition of the present embodiment has the following advantages because of the above-described configuration.

That is, the resin composition of the present invention is a resin composition containing an epoxy resin, a coupling agent and an inorganic filler,

the coupling agent is at least 1 selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3).

(wherein, in the general formula (1), R¹、R²And R³Are respectively CH₃Or C₂H₅。)

(wherein, in the general formula (2), R¹、R²And R³Are respectively CH₃Or C₂H₅。)

(wherein, in the general formula (3), n is an integer of 13 to 19, R⁴Each independently an alkyl group or an alkyl ether group having 8 to 12 carbon atoms, wherein the alkyl moiety is a linear saturated hydrocarbon or a branched hydrocarbon containing an unsaturated bond. )

According to the resin composition of the present embodiment, when a cured product is obtained, sufficient adhesive strength with an adherend can be ensured.

The resin composition of the present invention is not limited to the above embodiment. In addition, the resin composition of the present invention is not limited by the above-described effects. The resin composition of the present invention can be variously modified within the range not departing from the gist of the present invention.

Examples

The present invention will be described in more detail below with reference to examples and comparative examples.

(example 1)

The resin composition was obtained by mixing the following epoxy resin, the following curing agent, the following curing accelerator, the following silane coupling agent, and the following inorganic filler.

Epoxy resin: bisphenol A epoxy resin

Curing agent: novolac type phenol resin

Curing accelerator: tetraphenylphosphonium tetraphenylphosphonate (TPP-K (registered trademark), manufactured by Beixing chemical industry Co., Ltd.)

Silane coupling agent: silane coupling agent of the following formula (1)' (Compound name: 8-methacryloyloxyoctyltrimethoxysilane; commercially available product)

Inorganic filler: boron nitride packing (BN packing)

The epoxy resin and the curing agent are mixed in an equivalent ratio of 1: 1 is contained in the resin composition.

The curing accelerator is contained in the resin composition in an amount of 0.01 part by mass based on 100 parts by mass of the total amount of the epoxy resin and the curing agent.

Further, the inorganic filler is contained in the resin composition so that the content ratio of the inorganic filler is 59 vol% when the solid content of a cured product of the resin composition is 100 vol% after the resin composition is cured.

The silane coupling agent was contained in an amount of 0.015 mass% based on the mass of the inorganic filler contained in the resin composition.

(example 2)

A resin composition was obtained in the same manner as in example 1, except that a silane coupling agent of the following formula (2)' (compound name: 7-octenyltrimethoxysilane; commercially available product) was used as the silane coupling agent.

(example 3)

A resin composition was obtained in the same manner as in example 1 except that a titanate coupling agent of the following formula (3)' (compound name: tetrakis (2, 2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphoroyloxytitanate; commercially available product) was used in place of the silane coupling agent.

(example 4)

A resin composition was obtained in the same manner as in example 1, except that a titanate coupling agent (compound name: tetraoctylbis (ditridecylphosphonooxy) titanate; commercially available product) of the following formula (3) "was used in place of the silane coupling agent.

Comparative example

A resin composition was obtained in the same manner as in example 1, except that a silane coupling agent represented by the following formula (5) (compound name: 3-glycidoxypropyltrimethoxysilane; commercially available product) was used as the silane coupling agent.

< Peel test >)

Each of the resin compositions of examples and comparative examples was applied to one surface of an electrolytic copper foil (thickness: 35 μm) to prepare 2 sheets each having a resin layer (thickness: 145 μm).

Then, 2 sheets were hot-pressed (3.0MPa, 120 ℃ C., 20min) to bond the resin layers to each other, and 1 copper foil was peeled from the back surface of the sheet.

Then, an aluminum plate was placed on the surface from which the copper foil was peeled, and the sheet was transferred to the aluminum plate by hot pressing (2.0MPa, 120 ℃, 20min), and the copper foil was further peeled from the sheet, thereby obtaining a semi-cured sheet.

Then, an adherend (copper foil 1oz) was laminated on the semi-cured sheet, and the resin layer and the adherend were integrated by hot pressing (2.0MPa, 180 ℃, 120min) to sufficiently cure the resin layer. After curing, the resin layer and the adherend integrated were cut into a size of 20mm × 100 mm. The adherend of the cut-out material was processed (etched) to have a width of 10mm, to prepare a test piece for a peel test.

The test piece was subjected to a 90 ° peel test at a peel speed of 50mm/min, and the adhesive strength between the adherend and the resin layer was evaluated by the peel strength.

The results are shown in table 1 below. In table 1 below, the arithmetic average Ave (average) of the values obtained in 6 tests is shown as the peel strength.

[ Table 1]

As shown in table 1, it was confirmed that the peel strength of the cured products of the resin compositions of examples 1 and 2 was improved by about 30% as compared with the resin composition of the comparative example.

In addition, it was confirmed that the resin compositions of examples 3 and 4 improved the peel strength of the cured product by 55% or more as compared with the resin composition of comparative example.

The thermal conductivity was 11W/mK.

As described above, it is considered that the specific coupling agent of the examples can improve the cohesive failure strength of the cured product after curing. It is considered that since the destruction of the cured product itself is suppressed when the cohesive destruction is suppressed, the peeling force at the interface between the adherend and the cured product can directly reflect the adhesive force.