JP6875176B2 - Inorganic filler-containing photocurable composition and inorganic filler-containing sheet - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention includes an inorganic filler-containing photocurable composition which can sufficiently exert the effect of blending the inorganic filler and has excellent adhesiveness even though it contains a large amount of the inorganic filler, and the inorganic filler. The present invention relates to an inorganic filler-containing sheet made of a contained photocurable composition.

In various fields, photocurable compositions containing various inorganic fillers are used. For example, a photocurable composition containing a thermally conductive filler as an inorganic filler is used for a heat-dissipating paste or the like (for example, Patent Documents 1, 2, etc.), and a photocurable composition containing a conductive filler as an inorganic filler. The composition is used for conductive bonding of electronic parts and the like.

For example, in recent years, with the miniaturization and higher performance of electronic devices, the density of built-in electronic devices has been increasing, and the amount of heat generated per unit area of the electronic devices is increasing. Accumulation of heat in an electronic device causes a decrease in reliability, so how to efficiently release the generated heat to the outside has become an important issue. Therefore, higher thermal conductivity is also required for thermally conductive photocurable compositions.

Here, in order to improve the thermal conductivity of the photocurable composition, it is conceivable to add a larger amount of the thermally conductive filler. In response to the recent demand for high thermal conductivity, a photocurable composition containing a thermally conductive filler that greatly exceeds 50% by weight has also been proposed. However, there is a problem that the photocurable composition containing a large amount of heat conductive filler may not exhibit high heat conductivity as expected. In addition, the photocurable composition containing a large amount of heat conductive filler has been problematic in terms of adhesiveness.

Japanese Unexamined Patent Publication No. 2014-24965 Japanese Unexamined Patent Publication No. 2012-229342

Despite containing a large amount of inorganic filler, the present inventor can sufficiently exert the effect of blending the inorganic filler, and the inorganic filler-containing photocurable composition having excellent adhesiveness, and the inorganic. An object of the present invention is to provide an inorganic filler-containing sheet using a filler-containing photocurable composition.

The present invention is an inorganic filler-containing photocurable composition containing a photoradical polymerizable compound, a photoradical polymerization initiator, a chain transfer agent, a non-radical polymerizable plasticizer, and an inorganic filler.
The present invention will be described in detail below.

The present inventors have investigated the cause of not exhibiting the expected performance in a photocurable composition that exhibits thermal conductivity and adhesiveness by blending an inorganic filler, even though a large amount of the inorganic filler is blended. Was done. As a result, in the photocurable composition containing a large amount of inorganic filler, the penetration of light into the inside is hindered by the inorganic filler when irradiated with light, so that the internal curing is insufficient. I found out that it was the cause. The reason for this is not clear, but it was thought that if there was an uncured part in the cured product, the inorganic filler would move more easily in the cured product.
Therefore, the present inventors examined the combined use of a chain transfer agent in order to improve the curability of the photocurable composition. A chain transfer agent is an agent capable of reacting with the end of a growing polymer chain in radical polymerization to stop the growth of the polymer and at the same time generate a new polymerization initiation radical. By blending the chain transfer agent, it was expected that even the portion where the light irradiation was blocked by the inorganic filler could be sufficiently cured. However, in reality, even if a chain transfer agent was added, the portion where the light irradiation was blocked by the inorganic filler could not be sufficiently cured, and the desired performance could not be obtained.

As a result of further diligent studies, the present inventors can sufficiently cure the portion whose light irradiation is blocked by the inorganic filler for the first time by using a non-radical polymerizable plasticizer together with the chain transfer agent. The present invention has been completed by finding that it is possible to provide a photocurable composition which can sufficiently exert the effect of blending a filler and also has excellent adhesiveness. This is because the chain transfer agent can be sufficiently moved and diffused by the composition during photocuring by using a non-radical polymerizable plasticizer in combination, so that even the portion where light irradiation is inhibited is sufficiently cured. It is thought that this is because it can be made to.

The inorganic filler-containing photocurable composition of the present invention (hereinafter, also simply referred to as “photocurable composition”) is a photoradical polymerizable compound, a photoradical polymerization initiator, a chain transfer agent, or a non-radical polymerizable plastic. , And contains an inorganic filler.
The photoradical polymerizable compound is not particularly limited, but a compound having an unsaturated double bond is preferable, and a compound having a (meth) acryloyloxy group is more preferable because it is excellent in reactivity. Further, since the adhesiveness after curing is excellent, a photoradical polymerizable compound in which the glass transition point of the cured product obtained by photocuring the photocurable composition is 30 ° C. or less is preferable.
In addition, in this specification, a (meth) acryloyloxy group means an acryloyloxy group or a methacryloyloxy group.

Examples of the compound having a (meth) acryloyloxy group include a (meth) acrylic acid ester and a compound having a (meth) acryloyloxy group in the molecule by modifying a reactive functional group. .. Of these, (meth) acrylic acid ester is preferable because polymerization or cross-linking proceeds rapidly with active radicals generated by irradiation with light.
In addition, in this specification, (meth) acrylic means acrylic or methacrylic.

Examples of the (meth) acrylic acid ester include an ester compound obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, and an epoxy obtained by reacting (meth) acrylic acid with an epoxy compound. Examples thereof include meta) acrylate and urethane (meth) acrylate obtained by reacting an isocyanate with a (meth) acrylic acid derivative having a hydroxyl group. Of these, an ester compound obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group is preferable.
In addition, in this specification, the said epoxy (meth) acrylate means a compound which reacted all the epoxy groups in an epoxy compound with (meth) acrylic acid.

The ester compound obtained by reacting the (meth) acrylic acid with a compound having a hydroxyl group is not particularly limited, and examples of the monofunctional one include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). ) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) ) Acrylate, Isobornyl (meth) acrylate, Cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tetrahydro Flufuryl (meth) acrylate, benzyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate , 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, imide (meth) acrylate , Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, iso Myristyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, bicyclopentenyl (meth) acrylate, isodecyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) Acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropylphthalate, glycidyl (meth) acrylate, 2- (meth) ) Acryloyloxyethyl phosphate and the like can be mentioned.

Among the ester compounds obtained by reacting the (meth) acrylic acid with a compound having a hydroxyl group, examples of the bifunctional ester compound include 1,4-butanediol di (meth) acrylate and 1,3-butane. Diol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonane diol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2-n-butyl-2 -Ethyl-1,3-propanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (Meta) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) ) Acrylic, Dimethyloldicyclopentadienyldi (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide-modified di (meth) acrylate of isocyanurate, 2-hydroxy -3- (Meta) acryloyloxypropyl (meth) acrylate, carbonate diol di (meth) acrylate, polyether diol di (meth) acrylate, polyester diol di (meth) acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene diol Di (meth) acrylate and the like can be mentioned.

Further, among the ester compounds obtained by reacting the (meth) acrylic acid with a compound having a hydroxyl group, those having trifunctionality or higher include, for example, pentaerythritol tri (meth) acrylate and trimethyl propantri (meth) acrylate. , Propylene oxide-added trimethylol propanetri (meth) acrylate, ethylene oxide-added trimethylol propanetri (meth) acrylate, caprolactone-modified trimethylol propanetri (meth) acrylate, ethylene oxide-added isocyanurate tri (meth) acrylate, dipentaerythritol penta Meta) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropantetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, glycerintri (meth) acrylate, propylene oxide addition Examples thereof include glycerin tri (meth) acrylate and tris (meth) acryloyloxyethyl phosphate.

The photoradical polymerization initiator is not particularly limited, and examples thereof include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanosen-based compounds, oxime ester-based compounds, benzoin ether-based compounds, benzyl, and thioxanthone. Be done.

Commercially available photoradical polymerization initiators include, for example, IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE651, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, Lucillin TPO (all manufactured by BASF). Examples thereof include benzoin ethyl ether and benzoin isopropyl ether (both manufactured by Tokyo Chemical Industry Co., Ltd.).

The content of the photoradical polymerization initiator has a preferable lower limit of 10 parts by weight with respect to 100 parts by weight of the photoradical polymerizable compound. By containing 10 parts by weight or more of the photoradical polymerization initiator, the photocurable composition of the present invention can be reliably cured by irradiation with light. A more preferable lower limit of the content of the photoradical polymerization initiator is 20 parts by weight. The upper limit of the content of the photoradical polymerization initiator is not particularly limited, but a preferable upper limit is 40 parts by weight, and a more preferable upper limit is 35 parts by weight.

The chain transfer agent is an agent capable of reacting with the end of a growing polymer chain in radical polymerization to stop the growth of the polymer and at the same time generate a new polymerization initiation radical. By blending such a chain transfer agent, even a portion where light irradiation is blocked by an inorganic filler can be sufficiently cured, and the desired performance of the photocurable composition of the present invention can be exhibited. ..

The chain transfer agent is not particularly limited, and examples thereof include compounds that carry a redox reaction and transfer radicals. Specific examples thereof include metal complexes, thiol compounds, non-conjugated vinyl monomers and the like. Of these, a metal complex or a non-conjugated vinyl monomer is preferable from the viewpoint of exhibiting good adhesiveness.
Examples of the metal complex include tin-based complexes such as dibutyltin dilaurate, zinc-based complexes such as ethylenediamine-N, N, N', N'-zinc acetate (II) disodium salt tetrahydrate, and the like. Examples thereof include ethylenediamine-N, N, N', N'-copper tetraacetate (II) disodium salt tetrahydrate, cobalt phthalocyanine and the like. Of these, tin-based complexes or zinc-based complexes are preferable.
The non-conjugated vinyl monomer means a monomer having a chain transfer constant _CM of 10,000 or more with respect to the monomer. Specific examples thereof include vinyl acetate and allyl acetate. Of these, vinyl acetate is preferable.

The preferable lower limit of the content of the chain transfer agent with respect to 100 parts by weight of the photoradical polymerizable compound is 10 parts by weight. By containing 10 parts by weight or more of the chain transfer agent, the photocurable composition of the present invention can be sufficiently cured even in a portion where light irradiation is hindered by an inorganic filler, so that the adhesiveness can be improved. Can be enhanced. A more preferable lower limit of the content of the chain transfer agent is 20 parts by weight. The upper limit of the content of the chain transfer agent is not particularly limited, but a preferable upper limit is 100 parts by weight, and a more preferable upper limit is 50 parts by weight.

The preferable lower limit of the content of the chain transfer agent with respect to 1 part by weight of the photoradical polymerization initiator is 0.1 part by weight. By setting the content of the chain transfer agent to 0.1 parts by weight or more, the photocurable composition of the present invention can be sufficiently cured even in a portion where light irradiation is inhibited by an inorganic filler. Therefore, the adhesiveness can be further improved. A more preferable lower limit of the content of the chain transfer agent is 0.2 parts by weight, and a more preferable lower limit is 0.5 parts by weight. The upper limit of the content of the chain transfer agent is not particularly limited, but from the viewpoint of sufficiently curing and further enhancing the adhesiveness, the preferable upper limit is 10 parts by weight, and the more preferable upper limit is 5 parts by weight.

When the non-radical polymerizable plasticizer is used in combination with the chain transfer agent, even a portion where light irradiation is inhibited by an inorganic filler can be sufficiently cured, and the desired photocurable composition of the present invention can be sufficiently cured. It plays a role in demonstrating performance.
The non-radical polymerizable plasticizer is not particularly limited as long as it is a plasticizer that does not have a radically polymerizable functional group. For example, an organic acid ester plasticizer such as a monobasic organic acid ester or a polybasic organic acid ester. , Conventionally known non-radical polymerizable plasticizers such as phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic subphosphate plasticizers can be used.

Examples of the non-radical polymerizable plastic agent include epoxy compounds, episulfide compounds, oxetane compounds, pyrrolidine compounds, tetrahydrofuran compounds, tetrahydrothiophene compounds, piperidine compounds, tetrahydropyran compounds, tetrahydrothiopyran compounds, hexamethyleneimine, and hexamethylene oxide. , Hexamethylene sulfide compounds and other alicyclic compounds having heteroatomic substitutions can also be preferably used. When a compound having a heteroatom substitution product of such an alicyclic compound is blended, the photocurable composition of the present invention can be imparted with thermosetting property, and further by heating after photocuring. It is also possible to cure it reliably. Of these, epoxy compounds are preferable because they are more excellent in adhesive reliability, thermal conductivity, and thermosetting property.

The content of the non-radical polymerizable plasticizer is preferably 5 parts by weight with respect to 100 parts by weight of the photoradical polymerizable compound. When the content of the non-radical polymerizable plasticizer is 5 parts by weight or more, the photocurable composition of the present invention can be sufficiently cured even in a portion where light irradiation is inhibited by an inorganic filler. it can. A more preferable lower limit of the content of the non-radical polymerizable plasticizer is 10 parts by weight. The upper limit of the content of the non-radical polymerizable plasticizer is not particularly limited, but a preferable upper limit is 400 parts by weight, and a more preferable upper limit is 150 parts by weight.

The inorganic filler has a role of imparting various properties to the photocurable composition of the present invention. For example, by blending a thermally conductive filler as an inorganic filler, it is possible to provide a thermally conductive resin composition in which thermal conductivity is imparted to the photocurable composition. Further, by blending a conductive filler, it is possible to provide a conductive resin composition in which conductivity is imparted to the photocurable composition.

As the thermal conductive filler, for example, conventionally known thermal conductive fillers such as aluminum nitride, boron nitride, aluminum oxide, aluminum, silicon nitride, zirconia, and magnesium oxide can be used.
As the conductive filler, for example, a conductive metal such as copper, nickel, silver, or nickel, or a conventionally known conductive filler such as carbon black can be used.

The content of the inorganic filler is not particularly limited, but in recent years, there has been a tendency to blend a larger amount of the inorganic filler for the purpose of higher performance, and the content is 50% by weight or more, 80% by weight, based on the weight of the photocurable composition. It may contain an inorganic filler of% or more and 90% by weight or more. Even when the photocurable composition of the present invention contains such a large amount of inorganic filler, it can be sufficiently cured to the inside by light irradiation, and the effect of blending the inorganic filler can be sufficiently exhibited. it can.

When the photocurable composition of the present invention contains a compound having a heteroatom substituent of an alicyclic compound as the non-radical polymerizable plasticizer, it preferably contains a thermosetting agent.
The thermosetting agent is not particularly limited, and conventionally known thermosetting agents such as hydrazide-based curing agents, imidazole-based curing agents, polyhydric phenol-based curing agents, and acid anhydride-based curing agents can be used.

If necessary, the photocurable composition of the present invention may further contain conventionally known additives such as emulsifiers, softeners, fillers, pigments, dyes, silane coupling agents, and antioxidants. Good.

The method for producing the photocurable composition of the present invention is not particularly limited, and for example, the above photoradical polymerization is carried out using a mixer such as a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and three rolls. Examples thereof include a method of mixing a sex compound, a photoradical polymerization initiator, a chain transfer agent, a non-radical polymerizable plasticizer, an inorganic filler and an additive to be blended if necessary.

In the photocurable composition of the present invention, the shore hardness of the cured product obtained by photocuring is preferably less than A80. When the shore hardness of the cured product is less than A80, the cured product has a certain degree of flexibility and can exhibit better adhesiveness.
The shore hardness of the cured product can be measured by, for example, the following method.
First, the photocurable composition of the present invention is applied onto a release film so as to have a thickness of 500 μm, and then light having a wavelength of 410 nm is irradiated at an illuminance of ^{500 mW / cm 2 using a high-pressure mercury lamp and the irradiation amount is 1000 mJ.} Irradiate to / cm ² to obtain a cured product. The obtained cured product is allowed to stand at 25 ° C. for 60 minutes and used as a test piece. The shore hardness of the obtained test piece is measured using a rubber hardness tester (for example, Teclock Co., Ltd., A-type durometer, etc.) by a method according to JIS K 6253.

An inorganic filler-containing sheet using the photocurable composition of the present invention is also one of the present inventions.
The inorganic filler-containing sheet of the present invention can be produced, for example, by applying the photocurable composition of the present invention onto a release-treated film and irradiating it with light to cure it.

According to the present invention, an inorganic filler-containing photocurable composition capable of sufficiently exerting the effect of blending the inorganic filler and having excellent adhesiveness even though it contains a large amount of the inorganic filler, and the above-mentioned It is possible to provide an inorganic filler-containing sheet using an inorganic filler-containing photocurable composition.

It is a schematic diagram explaining the test piece used for the tensile shear adhesive strength test method of the adhesive in an Example.

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

(Example 1)
As a photoradical polymerizable compound, 46 parts by weight of 2-ethylhexyl acrylate (manufactured by Mitsubishi Chemical Co., Ltd.), 5 parts by weight of ethoxylated pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., ATM-35E), acrylic acid (manufactured by Mitsubishi Chemical Co., Ltd.) 3 parts by weight, 12 parts by weight of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (TPO, manufactured by BASF) as a photoradical polymerization initiator, bis (2,4,6-trimethylbenzoyl) -phenylphos 6 parts by weight of fin oxide (BASF, Irgacure 819), 16 parts by weight of dibutyltin dilaurylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a chain transfer agent, and bisphenol A type epoxy monomer (manufactured by Mitsubishi Chemical Co., Ltd.) as a non-radical polymerizable plastic agent. , JER828) 99 parts by weight, aluminum oxide (manufactured by Showa Denko, AS-40) 640 parts by weight, aluminum oxide (manufactured by Admatex, AO-502) 160 parts by weight, homodisper type The mixture was stirred and mixed for 30 minutes using a stirrer. Then, vacuum defoaming was performed to prepare a photocurable composition.

(Examples 2 to 4, Comparative Examples 1 to 6)
A photocurable composition was obtained in the same manner as in Example 1 except that the blending amounts of each component were as shown in Table 1. In Table 1, DISPERBYK111 used as a non-radical polymerizable plasticizer is manufactured by Big Chemie Japan. The vinyl acetate used as the chain transfer agent is manufactured by Tokyo Chemical Industry Co., Ltd. EH-5030S used as a thermosetting agent is a modified polyamine curing agent manufactured by ADEKA Corporation.

(Evaluation)
The photocurable compositions obtained in Examples and Comparative Examples were evaluated by the following methods.
The results are shown in Table 1.

(1) Evaluation of Thermal Conductivity The obtained photocurable composition was applied onto a release film so as to have a thickness of 500 μm. Then, a high-pressure mercury lamp was used to irradiate light having a wavelength of 410 nm with an illuminance of 500 mW / cm ^{2 so} that the irradiation amount was 1000 mJ / cm ² . A test piece was obtained by stacking a release film on the cured product after light irradiation, placing a weight of 100 g on the cured product, and allowing the film to stand at 25 ° C. for 60 minutes. As for the photocurable composition obtained in Example 4, a test piece obtained by the same method was further heat-treated at 100 ° C. for 30 minutes to obtain a test piece.
The thermal conductivity of the obtained test piece was measured by a steady-state method.

(2) Evaluation of tensile shear force A tensile shear adhesive strength test of the photocurable composition was carried out by a method according to JIS K6850.
That is, the obtained photocurable composition was applied onto an aluminum plate (manufactured by Nippon Test Panel Co., Ltd., A1050P) so as to have a width of 25 mm, a length of 10 mm, and a thickness of 500 μm. Then, a high-pressure mercury lamp was used to irradiate light having a wavelength of 410 nm with an illuminance of 500 mW / cm ^{2 so} that the irradiation amount was 1000 mJ / cm ² . A copper plate (C1100 manufactured by Nippon Test Panel Co., Ltd.) was placed on the cured product after light irradiation, a weight of 100 g was placed on the cured product, and the mixture was allowed to stand at 25 ° C. for 60 minutes to perform a test as shown in FIG. I got a piece. As for the photocurable composition obtained in Example 4, a test piece obtained by the same method was further heat-treated at 100 ° C. for 30 minutes to obtain a test piece.
Using a tensile tester, the obtained test piece was pulled parallel to the adhesive surface at 23 ° C. and a crosshead speed of 50 mm / min to determine the maximum load when it broke, and this was calculated as the adhesive area (shear area). The tensile shear force (kPa) was calculated by dividing by.
However, the tensile shear force of the test pieces prepared using the photocurable compositions of Comparative Examples 1 to 6 could not be measured because they spontaneously peeled off when attached to the tensile tester.

(3) Evaluation of Shore Hardness (Shore A) The obtained photocurable composition was applied onto a release film so as to have a thickness of 500 μm. Then, a high-pressure mercury lamp was used to irradiate light having a wavelength of 410 nm with an illuminance of 500 mW / cm ^{2 so} that the irradiation amount was 1000 mJ / cm ² . A test piece was obtained by stacking a release film on the cured product after light irradiation, placing a weight of 100 g on the cured product, and allowing the film to stand at 25 ° C. for 60 minutes. As for the photocurable composition obtained in Example 4, a test piece obtained by the same method was further heat-treated at 100 ° C. for 30 minutes to obtain a test piece.
The shore hardness of the obtained test piece was measured using a rubber hardness tester (A type durometer manufactured by Teclock Co., Ltd.) by a method according to JIS K 6253.
However, with respect to the test pieces prepared using the photocurable compositions of Comparative Examples 1 to 3, the shore hardness could not be measured because the probe was buried and displayed as 0 on the durometer.

According to the present invention, an inorganic filler-containing photocurable composition capable of sufficiently exerting the effect of blending the inorganic filler and having excellent adhesiveness even though it contains a large amount of the inorganic filler, and the above-mentioned It is possible to provide an inorganic filler-containing sheet using an inorganic filler-containing photocurable composition.

1 Substrate (aluminum plate and copper plate)
2 Support (same thickness and quality as the substrate material)
3 Adhesive part 4 Grasp part

Claims (11)

An inorganic filler-containing photocurable composition containing a photoradical polymerizable compound, a photoradical polymerization initiator, a chain transfer agent, a non-radical polymerizable plasticizer, and an inorganic filler.
With respect to 100 parts by weight of the photoradical polymerizable compound, 10 parts by weight or more of the photoradical polymerization initiator, 10 parts by weight or more of the chain transfer agent, and 5 parts by weight or more of the non-radical polymerizable plastic agent are contained. An inorganic filler-containing photocurable composition comprising The inorganic filler-containing photocurable composition according to claim 1 , wherein the shore hardness of the cured product obtained by photocuring the photocurable composition is less than A80. The inorganic filler-containing photocurable composition according to claim 1 or 2 , wherein the chain transfer agent is contained in an amount of 0.1 part by weight or more with respect to 1 part by weight of the photoradical polymerization initiator. The inorganic filler-containing photocurable composition according to claim 1, 2 or 3 , wherein the non-radical polymerizable plasticizer is a compound having a heteroatom substitution product of an alicyclic compound. The inorganic filler-containing photocurable composition according to claim 4, wherein the compound having a heteroatom substitution product of an alicyclic compound is an epoxy compound. The inorganic filler-containing photocurable composition according to claim 1, 2, 3, 4 or 5 , wherein the non-radical polymerizable plasticizer is contained in an amount of 10 to 400 parts by weight based on 100 parts by weight of the photoradical polymerizable compound. Stuff. The photocurable composition containing an inorganic filler according to claim 1, 2, 3, 4, 5 or 6 , wherein the inorganic filler is a thermally conductive filler. The inorganic filler-containing photocurable according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the content of the inorganic filler is 50% by weight or more based on the weight of the photocurable composition. Sex composition. The inorganic filler-containing photocurable composition according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the chain transfer agent is a tin complex or a non-conjugated vinyl monomer. The inorganic filler-containing photocurable composition according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the chain transfer agent is dibutyltin dilaurate or vinyl acetate. An inorganic filler-containing sheet according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, wherein the inorganic filler-containing photocurable composition is used.

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