JP2010018778A - Liquid thermosetting resin composition and copper-clad laminated plate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid thermosetting resin composition which contains an epoxy resin and a radically polymerizable compound, from which a thermoset product having high glass transition temperature (Tg) is obtained. <P>SOLUTION: The liquid thermosetting resin composition contains the epoxy resin (A) having two or more epoxy groups in one molecule thereof, the crosslinking and radically polymerizable compound (B) containing 3-13 equivalents/kg unsaturated double bond, a styrene monomer (C), an imidazole-based compound and a radical polymerization initiator (E). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid thermosetting resin composition used for producing a copper-clad laminate and the like, and a copper-clad laminate using the same.

  As liquid thermosetting resins used for the production of copper clad laminates and the like, radical polymerization resins such as epoxy resins and vinyl ester resins are widely used.

  Epoxy resin is excellent in the properties of the cured product, such as high toughness and heat resistance of the cured product, but it takes a long time for the curing reaction, and since the resin viscosity is high, it is suitable for substrates such as glass cloth. There was a drawback of poor impregnation.

  On the other hand, radical polymerization resins such as vinyl ester resins are excellent in impregnation properties and in that they are cured by a radical reaction due to decomposition of peroxides and therefore have a short curing time. However, there is a drawback in that the obtained cured product has low toughness and heat resistance.

  A thermosetting resin containing an epoxy resin and a radical polymerization resin as a resin component that makes use of the advantages of such an epoxy resin and a radical polymerization resin and compensates for the respective drawbacks is known (for example, the following patents) Reference 1). Such a thermosetting resin has improved impregnation property and curing speed, which are disadvantages of an epoxy resin, and improved toughness and heat resistance of a cured product, which are disadvantages of a radical polymerization type resin.

JP-A-8-118542

  In recent years, a thermosetting resin having a higher glass transition temperature (Tg) is required in order to maintain further heat resistance in a copper-clad laminate used as an electronic component. However, the thermosetting resin described in Patent Document 1 has a problem that the original Tg of the epoxy resin is lowered by mixing the radical polymerization resin. For this reason, the liquid thermosetting resin composition containing the radical polymerization type resin and the epoxy resin as resin components as described above could not obtain such a high Tg as when the epoxy resin was used alone.

  An object of this invention is to provide the liquid resin composition for obtaining the hardened | cured material which has a high glass transition temperature (Tg) in the resin composition containing an epoxy resin and a radically polymerizable compound.

  The liquid thermosetting resin composition of the present invention comprises (A) an epoxy resin having two or more epoxy groups in one molecule, and (B) a crosslinkable radical polymerization containing 3 to 13 equivalents / kg of unsaturated double bonds. A functional compound, (C) a styrene monomer, (D) an imidazole compound, and (E) a radical polymerization initiator. According to such a structure, in the resin composition containing an epoxy resin and a radical polymerizable compound, a crosslinkable radical polymerizable compound containing 3 to 13 equivalents / kg of unsaturated double bonds during curing ( Since B) forms a dense cross-linked structure, a high Tg can be imparted to the cured product. Moreover, the impregnation property with respect to the base material of a resin composition can be improved with a styrene-type monomer (C). And by using together radical polymerization and the thermosetting reaction of an epoxy resin, hardening faster than the composition which contains only an epoxy resin as a resin component is attained.

  Moreover, as said crosslinkable radically polymerizable compound (B), the crosslinkable monomer which has an unsaturated double bond 3-13 equivalent / kg and which has 2 or more unsaturated double bonds in 1 molecule is mentioned. It is preferable from the viewpoint that a cured product having a higher Tg can be obtained by forming a denser crosslinked structure with high reactivity.

  Examples of the crosslinkable monomer include dicyclopentadiene di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerin di (meth) acrylate, and Examples include pentaerythritol tri (meth) acrylate. Among these, a crosslinkable monomer such as dicyclopentadiene dimethacrylate or methacrylic anhydride that does not have a hydroxyl group in the molecule is preferable because a cured product having a higher Tg can be obtained.

  The crosslinkable radically polymerizable compound (B) contains 3 to 13 equivalents / kg of unsaturated double bonds, and a crosslinkable monomer and vinyl ester having two or more unsaturated double bonds in one molecule. When it contains resin, it is preferable from the point from which the hardened | cured material of higher Tg is obtained.

  Moreover, when (F) acrylic acid is further contained, it is preferable from the point from which the hardened | cured material of higher Tg is obtained.

  Moreover, (G) When it contains further the cyclic phosphazene compound which uses following Structural formula (1) as a repeating unit, it is preferable from the point which can provide a flame retardance, without reducing Tg.

（構造式（１）中、ｎは３〜２５の整数、Ｒ１及びＲ２は、それぞれアリール基または末端に不飽和結合を有する（メタ）アクリル酸エステル基であり、Ｒ１及びＲ２は同じでも異なっていてもよい）

(In Structural Formula (1), n is an integer of 3 to 25, R1 and R2 are each an aryl group or a (meth) acrylate group having an unsaturated bond at the terminal, and R1 and R2 are the same or different. May be)

  Moreover, when (H) liquid elastomer is contained, it is preferable from the point from which the hardened | cured material excellent in toughness is obtained.

  Further, when the content ratio of the component (A) and the component (B) in the liquid thermosetting resin composition is 20/80 to 80/20 (mass ratio), excellent curability is maintained. However, it is preferable from the viewpoint that high heat resistance and toughness can be maintained.

  Further, the copper clad laminate of the present invention was bonded to the surface of the resin insulation layer by impregnating the base material with the liquid thermosetting resin composition or coating the copper foil and curing the resin insulation layer. A copper foil layer or a substrate is provided.

  According to this invention, the liquid resin composition for obtaining the hardened | cured material which has a remarkably high glass transition temperature (Tg) in the resin composition containing an epoxy resin and a radically polymerizable compound is obtained.

  As the epoxy resin (A) having two or more epoxy groups in one molecule contained in the liquid thermosetting resin composition of the present invention, bisphenol containing two or more epoxy groups in one molecule Type epoxy resin, novolak type epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin and the like.

  Specific examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and the like. As the novolak type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin are used. Bisphenol A novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin and the like. These may be used alone or in combination of two or more.

  The number of epoxy groups in the epoxy resin (A) is not particularly limited as long as it is 2 or more in one molecule, but in consideration of production, it is preferable to use 5 or less epoxy resins in one molecule. .

  The crosslinkable radically polymerizable compound containing 3 to 13 equivalents / kg of unsaturated double bonds (B) contained in the liquid thermosetting resin composition of the present invention has at least two radical polymerizations in one molecule. It is a radically polymerizable compound having an unsaturated double bond having a content of 3 to 13 equivalents / Kg. Thus, by using a crosslinkable radical polymerizable compound having an unsaturated double bond in the above ratio in one molecule, an extremely dense cross-linked structure is formed in the obtained resin cured product, and the Tg of the cured product is remarkably increased. Can be improved.

Specific examples of the crosslinkable radically polymerizable compound (B) include, for example, dicyclopentadiene dimethacrylate (unsaturated double bond content: 6.0 equivalent / kg), dicyclopentadiene diacrylate (containing unsaturated double bond). 6.6 equivalents / Kg), trimethylolpropane trimethacrylate (unsaturated double bond content 8.9 equivalents / Kg), trimethylolpropane triacrylate (unsaturated double bond content 9.7 equivalents / Kg) Ethylene glycol dimethacrylate (unsaturated double bond content 6.1 equivalent / kg), ethylene glycol diacrylate (unsaturated double bond content 6.6 equivalent / kg), diethylene glycol dimethacrylate (containing unsaturated double bond) Amount 10.1 equivalent / kg), diethylene glycol diacrylate (unsaturated double bond content 11.8) Amount / kg), glycerin dimethacrylate (unsaturated double bond content 8.9 equivalents / kg), glycerin diacrylate (unsaturated double bond content 10.2 equivalents / kg), pentaerythritol triacrylate (unsaturated) Crosslink having two or more unsaturated double bonds in one molecule such as double bond content 8.9 equivalents / kg), methacrylic anhydride (unsaturated double bond content 13 equivalents / kg) A monomeric monomer; a vinyl ester resin (for example, unsaturated bis, manufactured by DIC Corporation), which is a reaction product of a bisphenol A type epoxy resin having an unsaturated double bond content of 3 to 13 equivalents / kg and methacrylic acid. Vinyl ester resin having a heavy bond content of 6.1 equivalents / Kg); a bisphenol A propylene oxide adduct having an unsaturated double bond content of 3-13 equivalents / Kg, and maleic anhydride Include those such as unsaturated polyester resin which is a reaction product of an acid or polybasic unsaturated acids such as fumaric acid. These may be used alone or in combination of two or more. Among these, dicyclopentadiene di (meth) acrylate and methacrylic anhydride having no hydroxyl group in the molecule are preferable from the viewpoint that higher Tg can be obtained because they are excellent in radical polymerizability.

  Further, those containing a crosslinkable monomer having 2 to 13 unsaturated double bonds and a vinyl ester resin containing 3 to 13 equivalents / kg of unsaturated double bonds are more dense. This is preferable from the viewpoint of forming a crosslinked structure to give a cured product having a higher Tg.

  The unsaturated double bond content in the crosslinkable radically polymerizable compound (B) is 3 to 13 equivalents / Kg, and preferably 6 to 13 equivalents / Kg. In such a range, since a dense cross-linked structure is formed, a cured product having a sufficiently high Tg can be obtained.

  In the liquid thermosetting resin composition of the present invention, (C) the styrenic monomer is used as a diluent for adjusting the viscosity of the liquid thermosetting resin composition, and part of the resin component by radical polymerization. It is the ingredient which becomes.

  (C) Specific examples of the styrene monomer include styrene, methyl styrene, halogenated styrene, and the like. These may be used alone or in combination of two or more. As a compounding quantity of a styrene-type monomer, it is preferable to mix | blend 15-40 mass% in a varnish, Furthermore, 20-30 mass% is mix | blended.

  The liquid thermosetting resin composition of the present invention may contain a radical polymerizable monomer other than the crosslinkable radical polymerizable compound (B) and the styrene monomer (C) within a range not impairing the effects of the present invention. Good. Specific examples of such polymerizable monomers include, for example, (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n- Alkyl (meth) acrylates such as hexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; unsaturated carboxylic acid allyl esters such as allyl (meth) acrylate; vinyl cyanide such as acrylonitrile and methacrylonitrile, vinylidene cyanide, etc. Vinyl monomers; and the like. These may be used alone or in combination of two or more. Among these, Tg of hardened | cured material can further be raised by mix | blending (meth) acrylic acid in a specific ratio. This is considered to be because the crosslinking of the epoxy resin and the resin obtained by radical polymerization is promoted by containing (meth) acrylic acid.

  It is preferable that the content rate of (meth) acrylic acid is 2-20 mass parts with respect to a total of 100 mass parts of (A) component and (B) component, Furthermore, it is 2-10 mass parts. When the content ratio of (meth) acrylic acid is too small, the effect of addition cannot be obtained sufficiently, and when it is too large, the water absorption rate of the cured product tends to increase.

The (D) imidazole compound contained in the liquid thermosetting resin composition of the present invention is used as a curing agent for the epoxy resin (A). (D) Specific examples of the imidazole compound include, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, and 2-phenyl-4. -Methylimidazole, 2-phenyl 6-4 ', 5'-dihydroxymethylimidazole, 1-cyanoethyl-2-ethyl-4methylimidazole and the like. These may be used alone or in combination of two or more. As the (D) imidazole compound used in the present invention, those containing no —NH ₂ and —OH groups are particularly preferred. -NH _2, and -OH groups inhibit radical reactions. Therefore, by using an imidazole compound not containing —NH ₂ and —OH groups, a radical thermoreactivity and a liquid thermosetting resin composition excellent in curability can be obtained.

  The content ratio of the (D) imidazole compound in the liquid thermosetting resin composition is not particularly limited as long as it is a ratio that sufficiently cures the epoxy resin (A), but is excellent in storage stability of varnish. From 0.1 to 2 parts by mass, and more preferably 0.5 to 1.5 parts by mass with respect to 100 parts by mass in total of the components (A), (B) and (C). .

  The radical polymerization initiator (E) contained in the liquid thermosetting resin composition of the present invention radically polymerizes radically polymerizable components such as the crosslinkable radically polymerizable compound (B) and the styrene monomer (C). For the initiator.

  Specific examples of the radical polymerization initiator (E) include, for example, ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide and cyclohexanone peroxide, diacyl peroxides such as benzoyl peroxide and isobutyl peroxide, cumene Hydroperoxides, hydroperoxides such as t-butyl hydroperoxide, dialkyl peroxides such as dicumyl peroxide, di-t-butyl peroxide, 1,1-di-t-butylperoxy-3, Peroxyketals such as 3,5-trimethylcyclohexanone and 2,2-di- (t-butylperoxy) -butane, alkyl such as t-butylperbenzoate and t-butylperoxy-2-ethylhexanoate Peresters, bis (4 t- butylcyclohexyl) peroxydicarbonate, and t- butyl peroxy isobutyl organic peroxides percarbonates, etc., such as carbonates, and inorganic peroxides such as hydrogen peroxide. These may be used alone or in combination of two or more.

  Although it does not specifically limit as a compounding quantity of a radical polymerization initiator (E), It is preferable that it is about 0.3-2 mass parts with respect to a total of 100 mass parts of (A) component and (B) component.

  The liquid thermosetting resin composition of the present invention may further contain an elastomer component such as a liquid elastomer or an incompatible elastomer.

  The liquid elastomer is a liquid elastomer component that is finely dispersed at the molecular level in the resin composition, and is a component that improves the toughness of the resulting cured product. By containing a liquid elastomer in the liquid thermosetting resin composition, a cured product having excellent toughness can be obtained. Therefore, even when subjected to a heat shock as in a thermal shock test, a cured product that is less prone to crack is obtained. Specific examples of such a liquid elastomer include liquid polybutadienes such as carboxyl group-terminated acrylonitrile butadiene (CTBN) and epoxidized polybutadiene, and low-volatile liquid rubbers such as liquid NBR.

  Other elastomer components include incompatible elastomers that are not compatible in the resin composition but are dispersed in islands. Such an incompatible elastomer can improve the impact resistance of the resulting cured product. When such an incompatible elastomer is contained, a cured product having excellent impact resistance can be obtained, and the hard and brittle characteristics of the radical polymerizable resin can be further improved. Examples of such an incompatible elastomer include various rubber particles, specifically, crosslinked or non-crosslinked rubber particles such as NBR rubber, SBR rubber, acrylic rubber, and silicone rubber. Moreover, as a form of rubber particles, a core-shell rubber having a core-shell structure is particularly preferable.

  As content of a liquid elastomer, it is 0.1-20 mass parts with respect to a total of 100 mass parts of said (A)-(E) component, Preferably it is 0.5-10 mass parts of hardened | cured material. This is preferable because the toughness can be sufficiently improved. Moreover, as content of an incompatible type | mold elastomer, it is 0.1-30 mass parts with respect to a total of 100 mass parts of the said (A)-(E) component, Preferably it is 0.5-10 weight part. It is preferable from the point that the impact resistance of the cured product can be sufficiently improved. When there is too much content of an elastomer component, there exists a tendency for the heat resistance to fall because the viscosity of a varnish rises and the elasticity modulus of hardened | cured material falls.

  The liquid thermosetting resin composition of the present invention preferably further contains an inorganic filler. An inorganic filler is mix | blended in order to maintain the dimensional stability of the hardened | cured material obtained and to raise a flame retardance.

  The type of the inorganic filler is not particularly limited, but specifically, for example, at least two metal elements selected from the group consisting of spherical silica, metal hydroxide such as aluminum hydroxide, nickel, iron, cobalt, and chromium A composite metal oxide containing is particularly preferably used. Among these, aluminum hydroxide is preferably used because it is particularly excellent in flame retardancy.

  As addition amount of an inorganic filler, it is 20-200 mass parts with respect to a total of 100 mass parts of said (A)-(E) component, and the dimensional stability and flame retardance of the hardened | cured material of a resin composition are included. It is preferable from the viewpoint that it can be sufficiently improved and the viscosity of the varnish of the resin composition is not extremely increased.

  In the liquid thermosetting resin composition of the present invention, a flame retardant, a flame retardant aid, a flow modifier, a lubricant, a silane coupling agent, a colorant and the like are further added within a range not impairing the object of the present invention. An agent may be blended.

  As the flame retardant, various reactive or additive type flame retardants, specifically, for example, cyclic phosphazene compounds, condensed phosphate esters, cyclic phosphate esters and the like are preferably used. Among these, the cyclic phosphazene compound represented by the following general formula (1) is particularly preferable.

（構造式（１）中、ｎは３〜２５の整数、Ｒ１及びＲ２は、それぞれアリール基または末端に不飽和結合を有する（メタ）アクリル酸エステル基であり、Ｒ１及びＲ２は同じでも異なっていてもよい）

(In Structural Formula (1), n is an integer of 3 to 25, R1 and R2 are each an aryl group or a (meth) acrylate group having an unsaturated bond at the terminal, and R1 and R2 are the same or different. May be)

The cyclic phosphazene compound represented by the general formula (1) has a low environmental load because it does not contain a halogen atom, and has excellent flame retardancy. In the general formula (1), n is an integer of 3 to 25, R1 and R2 are each an aryl group or a (meth) acrylate group having an unsaturated bond at the terminal, and R1 and R2 are the same. Or different. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and the (meth) acrylic acid ester group having an unsaturated bond at a terminal includes (—CH ₂ CH ₂ OCOC (CH ₃ ) ═CH ₂ ) And the like. Among these, it is preferable that R1 and / or R2 is a (meth) acrylic acid ester group having an unsaturated bond at the terminal. The (meth) acrylic acid ester group having an unsaturated bond at the terminal is a reactive functional group and is incorporated into the resin by radical polymerization reaction. Therefore, even if a relatively large amount of flame retardant is added, the cured product A cured product having high heat resistance can be obtained without lowering the Tg of the resin.

  As addition amount of a cyclic phosphazene compound, it is 10-80 mass parts with respect to 100 mass parts of total amounts of (A)-(E) component, Furthermore, it is T-50 of the hardened | cured material obtained that it is 15-50 mass parts. From the point which can fully provide a flame retardance, without reducing significantly.

  The liquid thermosetting resin composition is prepared by, for example, mixing liquid components among the above components to prepare a varnish, and further adding an insoluble component such as an inorganic filler or a flame retardant, and dispersing using a ball mill or the like. Prepared.

  Moreover, as copper foil used by this invention, if it is conventionally used for the use of a copper clad laminated board, it will be used without limitation, Specifically, electrolytic copper foil, rolled copper foil, etc. are used. Used.

  The heating conditions for curing the liquid thermosetting resin composition cannot be uniquely specified because it depends on the composition, but in consideration of continuous productivity, the heating condition is 10 at a temperature of about 80 to 200 ° C. It is preferable to heat for about 60 minutes.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the examples.

First, the raw materials used in this example are shown together.
(Epoxy resin containing two or more epoxy groups in one molecule)
・ EPPN-502H (Nippon Kayaku)
(Crosslinkable radical polymerizable compound)
・ Trimethylolpropane trimethacrylate (having 3 unsaturated double bonds in one molecule, content of unsaturated double bonds is 8.9 equivalents / kg, manufactured by Shin-Nakamura Chemical)
・ Methacrylic anhydride (having two unsaturated double bonds in one molecule, and the unsaturated double bond content is 13 equivalents / kg)
・ Dicyclopentadiene dimethacrylate (having two unsaturated double bonds in one molecule, content of unsaturated double bonds is 6.0 equivalents / kg, manufactured by Shin-Nakamura Chemical)
-Vinyl ester resin, which is a reaction product of bisphenol A type epoxy resin and methacrylic acid (having an average of two unsaturated double bonds in one molecule and an unsaturated double bond content of 6.1 equivalents / kg) Manufactured by DIC)
Vinyl ester resin, which is a reaction product of bisphenol A type epoxy resin and methacrylic acid (having an average of two unsaturated double bonds in one molecule, and the content of unsaturated double bonds is 2.2 equivalents / kg) DIC UE-5101L)
(Styrene monomer)
・ Styrene (manufactured by Nippon Steel Chemical)
(Acrylic acid)
(Imidazole compounds)
1-cyanoethyl-2-ethyl-4-methylimidazole (2E4MZ-CN), manufactured by Shikoku Chemicals (radical polymerization initiator)
・ Cumene hydroperoxide (CHP)
(Liquid elastomer)
-Carboxyl-terminated acrylonitrile butadiene (CTBN, Hycar CTBN 1300 × 13 manufactured by Ube Industries)
(Flame retardants)
SPB100 manufactured by Otsuka Chemical whose main component is a cyclic phosphazene compound (average n = 3) represented by the structural formula (1).
(Inorganic filler)
・ Aluminum hydroxide CL303 (manufactured by Sumitomo Chemical)
・ Spherical silica (SiO ₂ ) SO25R (manufactured by Admatex)
(Examples 1-8 and Comparative Examples 1-3)
Each of the above components was weighed into a container at each blending ratio shown in Table 1 and mixed to prepare a varnish (resin solution). And the flame retardant and the inorganic filler were added to the said resin solution so that it might become the mixture ratio shown in Table 1, and the liquid resin composition of an Example and a comparative example was prepared by making it disperse | distribute with a bead mill.

  For each of the obtained liquid resin compositions, a glass cloth (1504 type plain weave) was stacked on a copper foil (JTC, manufactured by Nikko Metal), and then the glass cloth was impregnated with the liquid resin composition. . Then, a copper foil was placed on the upper surface of the glass cloth, put into an oven, heated at 105 ° C. for 10 minutes, and then cured under curing conditions of heating at 200 ° C. for 15 minutes to obtain a copper-clad laminate.

  Then, using the obtained copper-clad laminate, the dynamic viscoelastic behavior was measured using a viscoelastic spectrometer (manufactured by SII Nano Technology), and the glass transition point (Tg) was determined from the peak value of tan δ. .

  The results are shown in Table 1.

  As shown in Table 1, all of the copper clad laminates obtained using the resin compositions of Examples 1 to 8 according to the present invention had a high Tg of 215 ° C. or higher. In particular, the copper-clad laminate obtained using Examples 6 and 7 using methacrylic anhydride and dicyclopentadiene dimethacrylate, which are crosslinkable monomers having no hydroxyl group in the molecule, have a Tg of It was particularly high at 245 ° C or higher. Moreover, when Example 1 is compared with Example 2 or Example 5, Tg of the hardened | cured material of the resin composition of Examples 2 and 5 which contains both a crosslinkable monomer and vinyl ester resin is 240 degreeC or more. It was relatively high. Moreover, when Example 1 and Example 4 are compared, Tg of the hardened | cured material of the resin composition of Example 1 containing acrylic acid is 230 degreeC, The resin composition of Example 4 which does not contain acrylic acid The Tg of the cured product was significantly higher than 215 ° C. Further, the Tg of the cured product of the resin composition of Example 5 containing trimethylolpropane methacrylate and a vinyl ester resin having an unsaturated double bond content of 6.1 equivalents / Kg was as extremely high as 242 ° C. Further, the Tg of the cured product of the resin composition of Example 6 containing methacrylic anhydride having an unsaturated double bond content of 13 equivalents / Kg was the highest at 245 ° C.

  On the other hand, in Comparative Example 1, the Tg of the cured product of the resin composition using a vinyl ester having an unsaturated double bond content of 2.2 equivalents / Kg is as low as 172 ° C., which is a crosslinking density produced by radical polymerization reaction. This is thought to be due to sparseness. Furthermore, in Comparative Example 2, the Tg of the cured product of the resin composition using a resin composition not containing an epoxy resin was also low at 198 ° C.

Claims (11)

  (A) an epoxy resin having two or more epoxy groups in one molecule, (B) a crosslinkable radically polymerizable compound containing 3 to 13 equivalents / kg of unsaturated double bonds, (C) a styrene monomer, (D A liquid thermosetting resin composition comprising:) an imidazole compound, and (E) a radical polymerization initiator.   The crosslinkable radical polymerizable compound (B) contains a crosslinkable monomer having 2 to 13 unsaturated double bonds in one molecule, containing 3 to 13 equivalents / kg of unsaturated double bonds. Item 2. The liquid thermosetting resin composition according to Item 1.   The crosslinkable monomer is dicyclopentadiene di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerin di (meth) acrylate, and penta The liquid thermosetting resin composition according to claim 2, comprising at least one selected from the group consisting of erythritol tri (meth) acrylates.   The liquid thermosetting resin composition according to claim 2, wherein the crosslinkable monomer is a crosslinkable monomer having no hydroxyl group in the molecule.   The liquid thermosetting resin composition according to claim 4, wherein the crosslinkable monomer having no hydroxyl group in the molecule is dicyclopentadiene dimethacrylate and / or methacrylic anhydride.   The liquid thermosetting resin composition according to any one of claims 1 to 5, wherein the crosslinkable radically polymerizable compound (B) contains a vinyl ester resin.   The liquid thermosetting resin composition according to any one of claims 1 to 6, further comprising (F) (meth) acrylic acid. (G) The liquid thermosetting resin composition of any one of Claims 1-7 which further contains the cyclic phosphazene compound which uses the following structural formula (1) as a repeating unit.

(In Structural Formula (1), n is an integer of 3 to 25, R1 and R2 are each an aryl group or a (meth) acrylate group having an unsaturated bond at the terminal, and R1 and R2 are the same or different. May be)   (H) The liquid thermosetting resin composition according to any one of claims 1 to 8, further comprising a liquid elastomer.   The liquid thermosetting resin composition according to any one of claims 1 to 9, wherein the content ratio of the component (A) and the component (B) is 20/80 to 80/20 (mass ratio).   A resin insulation layer formed by impregnating a base material with the liquid thermosetting resin composition according to any one of claims 1 to 10, or being coated and cured on a copper foil, and bonded to the surface of the resin insulation layer. A copper clad laminate comprising a copper foil layer or a substrate.