JP7336288B2 - Curable resin compositions, dry films, resin-coated copper foils, prepregs, cured products, and electronic components - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable resin composition, a dry film, a resin-coated copper foil, a prepreg, a cured product, and an electronic component.

Conventionally, curable resin compositions containing epoxy resin as a main component have been used as one of the insulating materials for forming electronic parts such as printed wiring boards, and usually to impart various properties to the cured product. In addition, various curing agents are used in combination with epoxy resins (for example, Patent Document 1). From the viewpoint of reliability and the like, such curable resin compositions for forming insulating films of electronic parts are required to be capable of forming cured products having excellent heat resistance and adhesion. In recent years, with the adoption of high-speed communication, that is, with the increase in frequency, transmission loss tends to increase, so materials for electronic components are required to have a low dielectric loss tangent that can suppress transmission loss.

Japanese Patent No. 5396805

In recent years, due to the trend toward low dielectric loss tangent, there is a tendency to reduce the surface roughness of circuit boards in order to reduce transmission loss. However, when the roughness of the surface of the circuit board is reduced, there is a problem that the adhesiveness to the cured film formed on the surface is lowered.

Therefore, an object of the present invention is to provide a curable resin composition that provides a cured product having high heat resistance, high adhesion and low dielectric loss tangent, a dry film having a resin layer obtained from the composition, and a dry film having a resin layer obtained from the composition. The obtained resin-coated copper foil having a resin layer, the prepreg obtained from the composition, the composition, the resin layer of the dry film, the resin layer of the resin-coated copper foil or the cured product of the prepreg, and the cured product To provide an electronic component having

In order to reduce the dielectric loss tangent, it is conceivable to add a compound having an active ester group as a curing agent. It is thought that the glass transition temperature (Tg) of the cured product is lowered and the heat resistance is deteriorated, and normally, the compound having an active ester group exceeding the epoxy equivalent of the epoxy resin in the composition was not blended. . In addition, since a cured product having a high glass transition temperature (Tg) generally has a low peel strength, it has been difficult to achieve both the glass transition temperature (Tg) and adhesion. However, as a result of intensive studies aimed at realizing the above object, the present inventors unexpectedly formulated a compound having an active ester group in a specific amount exceeding the epoxy equivalent of the epoxy resin, and By blending a liquid or semi-solid epoxy resin with an epoxy equivalent weight, it was found that a cured product having a high glass transition temperature (Tg) and excellent adhesion and dielectric properties could be obtained, leading to the completion of the present invention. .

That is, the curable resin composition of the present invention is a composition containing (A) an epoxy resin and (B) a compound having an active ester group, wherein (A) the epoxy resin is (A1) epoxy equivalent weight is 350-1000g/eq. wherein the ratio of the total amount of epoxy groups of the (A) epoxy resin/total amount of the active ester groups of the compound having the (B) active ester group in the composition is 0.2 to 0.6.

（式中、Ｘ_１はベンゼン環またはナフタレン環を有する基であり、ｋは０または１を表し、ｎは繰り返し単位の平均で０．２５～１．５である。）で表される化合物であることが好ましい。 In the curable resin composition of the present invention, the compound (B) having an active ester group is represented by the following general formula (1)

(Wherein, X ₁ is a group having a benzene ring or a naphthalene ring, k represents 0 or 1, and n is an average repeating unit of 0.25 to 1.5.) Preferably.

（式（２）中、Ｘ_２はそれぞれ独立的に下記式（３）：

で表される基または下記式（４）：

で表される基であり、
ｍは１～６の整数であり、ｎはそれぞれ独立的に１～５の整数であり、ｑはそれぞれ独立的に１～６の整数であり、
式（３）中、ｋはそれぞれ独立的に１～５の整数であり、
式（４）中、Ｙは上記式（３）で表される基（ｋはそれぞれ独立的に１～５の整数）であり、ｔはそれぞれ独立的に０～５の整数である）
で表される構造部位を有し、その両末端が一価のアリールオキシ基である樹脂構造を有する活性エステル樹脂であることが好ましい。 In the curable resin composition of the present invention, the compound (B) having an active ester group is represented by the following general formula (2)

(In formula (2), each of X ₂ is independently represented by the following formula (3):

or the following formula (4):

is a group represented by
m is an integer of 1 to 6, n is each independently an integer of 1 to 5, q is each independently an integer of 1 to 6,
In formula (3), k is each independently an integer of 1 to 5,
In formula (4), Y is a group represented by formula (3) above (k is independently an integer of 1 to 5), and t is independently an integer of 0 to 5)
It is preferably an active ester resin having a resin structure having a structural site represented by and both ends of which are monovalent aryloxy groups.

（式（５）中、Ｒ_１は芳香環を含む炭素数６～５０の二価の有機基であり、Ｒ_２は炭素数２～５０の二価の有機基であり、ｍは１～５０の整数であり、ｎは０～５０の整数であり、ｌは０～２０の整数である。）で表される化合物であることが好ましい。 In the curable resin composition of the present invention, the epoxy resin (A1) is represented by the following general formula (5)

(In formula (5), R ₁ is a divalent organic group having 6 to 50 carbon atoms containing an aromatic ring, R ₂ is a divalent organic group having 2 to 50 carbon atoms, and m is 1 to 50 is an integer of , n is an integer of 0 to 50, and l is an integer of 0 to 20.).

The dry film of the present invention is characterized by having a resin layer obtained by coating and drying the curable resin composition on the film.

The resin-coated copper foil of the present invention is characterized by having a resin layer obtained by applying the curable resin composition to a copper foil or an ultra-thin copper foil with a carrier, followed by drying.

The prepreg of the present invention is characterized by being obtained by coating and/or impregnating a sheet-like fibrous base material with the curable resin composition, followed by drying.

The cured product of the present invention is obtained by curing the curable resin composition, the resin layer of the dry film, the resin layer of the resin-coated copper foil, or the prepreg.

The electronic component of the present invention is characterized by having the cured product.

According to the present invention, a curable resin composition that provides a cured product having both high heat resistance, high adhesion and low dielectric loss tangent, a dry film having a resin layer obtained from the composition, and a dry film obtained from the composition. a resin-coated copper foil having a resin layer obtained from the composition, a prepreg obtained from the composition, the composition, the resin layer of the dry film, the resin layer of the resin-coated copper foil or a cured product of the prepreg, and the cured product It is possible to provide an electronic component having

The curable resin composition of the present invention is a composition containing (A) an epoxy resin and (B) a compound having an active ester group, wherein the (A) epoxy resin has (A1) an epoxy equivalent of 350-1000 g/eq. A liquid or semi-solid epoxy resin (hereinafter also referred to as "(A1) epoxy resin"), and the total amount of epoxy groups of the (A) epoxy resin in the composition / the (B) compound having an active ester group The ratio of the total amount of active ester groups of is 0.2 to 0.6. As described above, when a large amount of a compound having an active ester group is added as a curing agent, it is thought that the heat resistance deteriorates, and it is thought that it is difficult to achieve both the glass transition temperature (Tg) and the adhesion. According to the invention, unexpectedly, a cured product having a high glass transition temperature (Tg) and excellent adhesion and dielectric properties can be obtained. Although the detailed mechanism is not clear, when the ratio of the compound having an active ester group, preferably the compound having an active ester group having the structure of the general formula (1) or (2) is increased, the structure of the active ester, that is, It is considered that the increase in the volume ratio of the aromatic ester structure, which is rigid and has high molecular orientation, controls the movement of the chain-like portion between the cross-linking points, thereby improving the glass transition temperature. In addition, in the composition having a large proportion of the compound having an active ester group as described above, by blending an epoxy resin with a relatively high epoxy equivalent among liquid or semi-solid epoxy resins, the toughness is improved and the inside of the cured product is improved. It is considered that the breakage was suppressed, the peel strength was improved, and both the glass transition temperature (Tg) and the adhesion were achieved.

The total amount of epoxy groups in the (A) epoxy resin can be obtained by dividing the amount of the (A) epoxy resin contained in the composition by the epoxy equivalent of the (A) epoxy resin. The total amount of the active ester group of the compound having an active ester group (B) is the amount of the compound having an active ester group (B) contained in the composition, and the active ester of the compound having an active ester group (B) It can be obtained by dividing by the equivalent.

In the present invention, the upper limit of the ratio of the total amount is preferably 0.5 or less, more preferably 0.4 or less, because a cured product with a lower dielectric loss tangent can be obtained. , 0.3 or less.

In the present invention, the ratio of the total amount of epoxy groups in the epoxy resin (A1) to the total amount of active ester groups in the compound having an active ester group (B) is preferably 0.5 or less. It is more preferably 4 or less. Further, since the glass transition temperature (Tg) becomes more favorable, it is preferably 0.3 or less, more preferably 0.2 or less. It is preferably 0.001 or more, more preferably 0.01 or more.

Each component contained in the curable resin composition of the present invention is described below. In this specification, when a numerical range is indicated by "-", it means a range including those numerical values (that is, .

[(A) epoxy resin]
The curable resin composition of the present invention contains (A) an epoxy resin having (A1) an epoxy equivalent of 350 to 1000 g/eq. of liquid or semi-solid epoxy resin. Here, the epoxy resin is a resin having an epoxy group, and examples thereof include bifunctional epoxy resins having two epoxy groups in the molecule and polyfunctional epoxy resins having many epoxy groups in the molecule. In addition, a hydrogenated bifunctional epoxy resin may be used. In this specification, a liquid epoxy resin refers to an epoxy resin that is liquid at 20°C, and a semi-solid epoxy resin refers to an epoxy resin that is solid at 20°C and liquid at 40°C. A solid epoxy resin to be described later refers to an epoxy resin that is solid at 40°C. Judgment of the liquid state shall be carried out according to the "Confirmation method of the liquid state" in Attachment No. 2 of the Ministerial Ordinance on the Test and Properties of Dangerous Substances (Ministry of Home Affairs Ordinance No. 1 of 1989). For example, the method described in paragraphs 23 to 25 of JP-A-2016-079384 is used.

(A1) The epoxy resin is preferably a bifunctional epoxy resin. Adhesion improves as it is a bifunctional epoxy resin. (A1) As the epoxy resin, for example, a compound represented by the following general formula (5) is more preferable.

（式（５）中、Ｒ_１は芳香環を含む炭素数６～５０の二価の有機基であり、Ｒ_２は炭素数２～５０の二価の有機基であり、ｍは１～５０の整数であり、ｎは０～５０の整数であり、ｌは０～２０の整数である。）

(In formula (5), R ₁ is a divalent organic group having 6 to 50 carbon atoms containing an aromatic ring, R ₂ is a divalent organic group having 2 to 50 carbon atoms, and m is 1 to 50 is an integer of , n is an integer of 0 to 50, and l is an integer of 0 to 20.)

In formula (5), examples of the aromatic ring contained in the divalent organic group represented by R ₁ include a benzene ring and a naphthalene ring. It may contain a plurality of aromatic rings, and may be, for example, an organic group having a biphenyl structure or a bisphenol structure such as bisphenol A and bisphenol F. In addition, the aromatic ring may form a bisphenol structure together with the oxygen atom bonded to _R1 . In the present specification, the bisphenol structure is a structure that does not contain a hydrogen atom of the hydroxyl group of bisphenol, and means a structure in which the oxygen atom of the hydroxyl group of bisphenol is bonded to an atom other than a hydrogen atom such as a carbon atom. The divalent organic group for R ₁ preferably has 6 to 30 carbon atoms.

The divalent organic group represented by R ₁ preferably has a bisphenol A structure or bisphenol F structure, or forms a bisphenol A structure or bisphenol F structure together with an oxygen atom bonded to R ₁ , such as a biphenyl structure or Compared with the naphthalene structure, toughness is improved and a cured product with excellent adhesion can be obtained.

Specific examples of the divalent organic group for R ₁ are shown below, but are not limited thereto.

In formula (5), the divalent organic group represented by R ₂ preferably has 2 to 40 carbon atoms. The divalent organic group for R ₂ preferably contains an aliphatic group, more preferably an aliphatic group having a divalent group "--O--CH ₂ --". Also, two or more aliphatic groups may be linked via an ether bond. The aliphatic group is preferably an alkylene group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, such as methylene, methylmethylene, ethylene, propylene, trimethylene, tetramethylene, penta methylene group, hexamethylene group, heptamethylene group, octamethylene group and the like.

The divalent organic group represented by R ₂ is more preferably a group represented by general formula (6) or (7) below.

In formulas (6) and (7), _R3 is a divalent organic group represented by formula (8) below.

In formula (8), p and q are each independently an integer of 1-50, and r is an integer of 0-50. When r is 0, R ₃ preferably has an alkylene structure and q is an integer of 2-20. An integer of 2-10 is more preferred. When r is an integer of 1-50, R ₃ has a polyalkylene glycol structure, and p and q are preferably integers of 1-10, more preferably integers of 1-5. r is preferably an integer of 1-10, more preferably an integer of 1-5.

In formula (5), m is preferably an integer of 1-10. When a plurality of compounds with different m are included, it is preferred that the compounds in which m is an integer of 1 to 10 are included most. In formula (5), n is preferably an integer of 0-10. When a plurality of compounds with different n are included, it is preferred that the compounds in which n is an integer of 0 to 10 are included most. In formula (5), l is preferably an integer of 0-5. When a plurality of compounds in which l is different are included, it is preferred that the compounds in which l is an integer of 0 to 5 are included most.

(A1) Specific examples of the epoxy resin are shown below, but the present invention is not limited to these.

各式中、ｋは、０～５０の整数であり、０～１０の整数であることが好ましく、０～５の整数であることがより好ましい。（Ａ１）エポキシ樹脂は、ｋ値の異なる混合物の場合もあり得る。ｋ値の平均値としては０．５～３であることが好ましい。

In each formula, k is an integer of 0-50, preferably an integer of 0-10, more preferably an integer of 0-5. (A1) Epoxy resins may be mixtures with different k values. The average k value is preferably 0.5-3.

As the epoxy resin (A1), the epoxy resins shown in (9) or (10) above are preferable. 1000 etc. are mentioned.

(A1) The epoxy equivalent of the epoxy resin is preferably 350 to 800 g/eq. is. In addition, the epoxy equivalent in the present invention is a value measured based on JIS K 7236.

(A1) Epoxy resins may be used singly or in combination of two or more. (A1) The amount of the epoxy resin to be blended is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, when the non-volatile component in the resin composition is 100% by mass.

The curable resin composition of the present invention may contain (A2) epoxy resin other than (A1) epoxy resin as (A) epoxy resin. Among them, it is preferable to contain a solid epoxy resin. The epoxy resin (A2) may be a liquid or semi-solid epoxy resin.

Solid epoxy resins include tetrafunctional naphthalene type epoxy resin such as HP-4700 manufactured by DIC Corporation, naphthalene skeleton-containing novolac type epoxy resin such as NC-7000 manufactured by Nippon Kayaku Co., Ltd., and ESN-475V manufactured by Nippon Steel Chemical & Materials Co., Ltd. Naphthol aralkyl type epoxy resins such as EPPN-502H manufactured by Nippon Kayaku Co., Ltd. Epoxidized products of condensation products of phenols and aromatic aldehydes having phenolic hydroxyl groups (trisphenol type epoxy resins), DIC Corporation Epiclon HP- Dicyclopentadiene type epoxy resins such as 7200H; Biphenylaralkyl type epoxy resins such as NC-3000H and NC-3000L manufactured by Nippon Kayaku; Novolak type such as Epiclon N-680 manufactured by DIC and EOCN-104S manufactured by Nippon Kayaku Epoxy resins, biphenyl type epoxy resins such as YX-4000 manufactured by Mitsubishi Chemical Co., Ltd., phosphorus-containing epoxy resins such as TX0712 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., tris(2,3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan Chemical Co., etc. mentioned. By containing a solid epoxy resin, the cured product has a high glass transition temperature and excellent heat resistance. Among solid epoxy resins, since a cured product with a higher Tg and a lower dielectric loss tangent can be obtained, aralkyl type epoxy resins such as ESN-475V and NC3000H, that is, divalent in which an alkylene group and an arylene group are bonded Epoxy resins containing the group are preferred. Here, the alkylene group includes methylene group, methylmethylene group, ethylene group, propylene group, trimethylene group and the like. A phenylene group, a biphenylene group, a naphthylene group, etc. are mentioned as an arylene group.

(A2) The epoxy equivalent of the epoxy resin is preferably 100 to 5000 g/eq. , more preferably 150 to 3000 g/eq. is.

(A2) Epoxy resins may be used singly or in combination of two or more. (A2) The blending amount of the epoxy resin is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, based on 100% by mass of non-volatile components in the resin composition.

The curable resin composition of the present invention may contain (A) a thermosetting resin other than an epoxy resin, such as isocyanate compounds, blocked isocyanate compounds, amino resins, Known and commonly used thermosetting resins such as benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, polyfunctional oxetane compounds, episulfide resins and maleimide resins can be used.

[(B) a compound having an active ester group]
(B) The compound having an active ester group is preferably a compound having two or more active ester groups in one molecule. A compound having an active ester group can generally be obtained by a condensation reaction between a carboxylic acid compound and a hydroxy compound. Among them, a compound having an active ester group obtained by using a phenol compound or a naphthol compound as the hydroxy compound is preferred. Phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucine, benzenetriol , dicyclopentadienyl diphenol, phenol novolac, and the like. Also, the compound (B) having an active ester group may be of the naphthalenediol alkyl/benzoic acid type. (B) Compounds having an active ester group may be used singly or in combination of two or more. (B) As the compound having an active ester group, one having a benzene, α-naphthol, β-naphthol or dicyclopentadiene skeleton is preferred.

(B) The compounding amount of the compound having an active ester group, when the non-volatile component in the resin composition is 100% by mass, from the viewpoint of the strength of the cured product, the upper limit is preferably 50% by mass or less. It is more preferably not more than 40% by mass, and particularly preferably not more than 40% by mass. Moreover, the lower limit is preferably 5% by mass or more, more preferably 10% by mass or more, because a cured product with a lower dielectric loss tangent can be obtained.

Among (B) compounds having an active ester group, the following compounds (B1) and (B2) having an active ester group can be preferably used.

(B1)
The compound having an active ester group (B1) includes (b1) a phenolic resin having a molecular structure in which phenols are knotted via an aliphatic cyclic hydrocarbon group, (b2) an aromatic dicarboxylic acid or a halide thereof, and (b3) It has a structure obtained by reacting an aromatic monohydroxy compound. 0.05 to 0.75 mol of the phenolic hydroxyl group in the phenolic resin (b1) per 1 mol of the carboxyl group or acid halide group in the (b2) aromatic dicarboxylic acid or its halide, and the (b3) It preferably has a structure obtained by reacting 0.25 to 0.95 mol of an aromatic monohydroxy compound.

Here, in the phenol resin (b1), the molecular structure in which phenols are knotted via an aliphatic cyclic hydrocarbon group means an unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule. Examples include structures obtained by polyaddition reaction with phenols. Examples of phenols include phenol and substituted phenols substituted with one or more alkyl groups, alkenyl groups, allyl groups, aryl groups, aralkyl groups, halogen groups, or the like. Specific examples include cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol, naphthol, and dihydroxynaphthalene. but not limited to these. A mixture of these may also be used. Among these, phenol is particularly preferred from the viewpoint of excellent fluidity and curability.

Further, specific examples of unsaturated alicyclic cyclic hydrocarbon compounds include dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, 5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene and the like. mentioned. Among these, dicyclopentadiene is preferable from the viewpoint of property balance, particularly heat resistance and hygroscopicity. Since dicyclopentadiene is contained in petroleum distillates, industrial dicyclopentadiene may contain other aliphatic or aromatic dienes as impurities. Considering moldability and the like, it is desirable that the product has a dicyclopentadiene purity of 90% by mass or more.

Next, the (b2) aromatic dicarboxylic acid or its halide includes aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, 1,4-, 2,3-, or 2,6-naphthalenedicarboxylic acid, and these acid halides such as acid fluorides, acid chlorides, acid bromides and acid iodides; Among these, acid chlorides of aromatic dicarboxylic acids are preferred because they have particularly good reactivity. Among them, dichlorides of isophthalic acid and dichlorides of terephthalic acid are preferred, and dichlorides of isophthalic acid are particularly preferred.

Examples of aromatic monohydroxy compounds include phenol; alkylphenols such as o-cresol, m-cresol, p-cresol and 3,5-xylenol; o-phenylphenol, p-phenylphenol, 2-benzyl Aralkylphenols such as phenol, 4-benzylphenol and 4-(α-cumyl)phenol; and naphthols such as α-naphthol and β-naphthol. Among these, α-naphthol and β-naphthol are particularly preferred because the dielectric loss tangent of the cured product is low.

（式中、Ｘ_１はベンゼン環またはナフタレン環を有する基であり、ｋは０または１を表し、ｎは繰り返し単位の平均値で０．０５～２．５である。）
で表される構造のものがとりわけ硬化物の誘電正接が低く、かつ、有機溶剤に溶解させた際の溶液粘度が低くなる点から好ましい。前記ベンゼン環またはナフタレン環を有する基は、特に限定されず、フェニル基、ナフチル基等でもよく、また、他の原子を介してベンゼン環またはナフタレン環が分子末端に結合していてもよく、置換基を有していてもよい。また、（Ｂ１）活性エステル化合物は、その分子末端にナフタレン環を有するものであることが好ましい。 (B1) the active ester compound has a structure obtained by reacting (b1) a phenol resin, (b2) an aromatic dicarboxylic acid or a halide thereof, and (b3) an aromatic monohydroxy compound; , the following general formula (1)

(Wherein, X ₁ is a group having a benzene ring or a naphthalene ring, k represents 0 or 1, and n is an average value of repeating units of 0.05 to 2.5.)
The structure represented by is particularly preferable because the dielectric loss tangent of the cured product is low and the solution viscosity when dissolved in an organic solvent is low. The group having a benzene ring or a naphthalene ring is not particularly limited, and may be a phenyl group, a naphthyl group, or the like, and a benzene ring or a naphthalene ring may be bonded to the terminal of the molecule via another atom. You may have a group. Also, (B1) the active ester compound preferably has a naphthalene ring at its molecular end.

In particular, when the value of n in the above general formula (1), that is, the average value of the repeating units is in the range of 0.25 to 1.5, the solution viscosity is low and it is easy to produce a dry film for buildup. It is preferable from the point that Moreover, in the above general formula (1), it is preferable that the value of k is 0 from the viewpoint of high heat resistance and low dielectric loss tangent.

Here, n in the above general formula (1) can be determined as follows.
[How to find n in general formula (1)]
Styrene equivalent molecular weights (α1, α2, α3, α4) corresponding to n = 1, n = 2, n = 3, n = 4 by GPC measurement performed under the following conditions, and n = 1, n = 2, n = 3, n = 4 and the theoretical molecular weights (β1, β2, β3, β4) of each ratio (β1 / α1, β2 / α2, β3 / α3, β4 / α4) are obtained, and these (β1 / Calculate the average value of α1 to β4/α4). The average molecular weight is obtained by multiplying the number average molecular weight (Mn) determined by GPC by this average value. Next, the value of n is calculated using the molecular weight of the general formula (1) as the average molecular weight.

(GPC measurement conditions)
Measuring device: "HLC-8220 GPC" manufactured by Tosoh Corporation,
Column: Guard column " _HXL -L" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh "TSK-GEL G3000HXL"
+ Tosoh "TSK-GEL G4000HXL"
Detector: RI (differential refraction diameter)
Data processing: "GPC-8020 model II version 4.10" manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40°C
Developing solvent Tetrahydrofuran Flow rate 1.0 ml/min Standard: The following monodisperse polystyrene having a known molecular weight was used according to the measurement manual of "GPC-8020 model II version 4.10".
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A 1.0% by mass tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (50 μl).

(b1) a phenol resin, (b2) an aromatic dicarboxylic acid or a halide thereof, and (b3) an aromatic monohydroxy compound are reacted, specifically, each of these components is reacted in the presence of an alkali catalyst. can be made
Alkaline catalysts that can be used here include sodium hydroxide, potassium hydroxide, triethylamine, pyridine, and the like. Among these, sodium hydroxide and potassium hydroxide are particularly preferred because they can be used in the form of an aqueous solution, resulting in good productivity.

Specifically, in the presence of an organic solvent, (b1) a phenolic resin, (b2) an aromatic dicarboxylic acid or its halide, and (b3) an aromatic monohydroxy compound are mixed, and the alkali catalyst or its A method of reacting while dropping an aqueous solution continuously or intermittently can be mentioned. At that time, the concentration of the aqueous alkali catalyst solution is preferably in the range of 3.0 to 30%. Moreover, toluene, dichloromethane, etc. are mentioned as an organic solvent which can be used here.

After completion of the reaction, when an aqueous solution of an alkali catalyst is used, the reaction solution is allowed to stand for liquid separation, the aqueous layer is removed, and the remaining organic layer is washed until the aqueous layer becomes almost neutral, The target resin can be obtained.

The compound (B1) having an active ester group thus obtained is usually obtained as an organic solvent solution. and furthermore, the desired curable resin composition can be produced by appropriately adjusting the amount of the organic solvent. The active ester compound (B1) is characterized by having a low melt viscosity when dissolved in an organic solvent to form a resin solution. The viscosity of the solution is 300 to 10,000 mPa·s (25° C.).

で表される構造部位を有し且つその両末端が一価のアリールオキシ基である樹脂構造を有するものである。 (B2)
The compound having an active ester group (B2) has the following general formula (2):

and has a resin structure in which both ends are monovalent aryloxy groups.

で表される基または下記式（４）：

で表される基であり、ｍは１～６の整数であり、ｎはそれぞれ独立的に１～５の整数であり、ｑはそれぞれ独立的に０～６の整数であり、式（３）中、ｋはそれぞれ独立的に１～５の整数であり、式（４）中、Ｙは上記式（３）で表される基（ｋはそれぞれ独立的に１～５の整数）であり、ｔはそれぞれ独立的に０～５の整数である） (In formula (2), each of X ₂ is independently represented by the following formula (3):

or the following formula (4):

is a group represented by m is an integer of 1 to 6, n is each independently an integer of 1 to 5, q is each independently an integer of 0 to 6, formula (3) wherein k are each independently an integer of 1 to 5, and in formula (4), Y is a group represented by the above formula (3) (k is each independently an integer of 1 to 5), t is independently an integer from 0 to 5)

で表される部分構造が、水酸基当量が１７０～２００ｇ／ｅｑ．の変性ナフタレン化合物の由来構造であることが好ましい。 The compound having an active ester group (B2) is represented by the general formula (2)

has a hydroxyl equivalent of 170 to 200 g/eq. is preferably a structure derived from the modified naphthalene compound.

In order to clarify the relationship between m and n in formula (2), several patterns are shown below, but the active ester resin (B2) is not limited to these.
For example, when m=1, formula (2) represents the structure of formula (2-I) below.

In formula (2-I), n is an integer of 1 to 5, and q is each independently an integer of 0 to 6. As with the relationship between m and n, q also indicates that each q is an integer of 0 to 6 independently when n is 2 or more.

Further, for example, when m=2, formula (2) represents the structure of formula (2-II) below.

In formula (2-II), each n is independently an integer of 1 to 5, and each q is independently an integer of 0 to 6. As with the relationship between m and n, q also indicates that each q is an integer of 0 to 6 independently when n is 2 or more.

で結合した構造を有することから、硬化物により優れた誘電特性を兼備させることができる。また、（Ｂ２）の活性エステル基を有する化合物の樹脂構造中、両末端の構造としてアリールオキシ基を有するものとしたことで、多層プリント基板用途においても十分高度な硬化物の耐熱分解性の向上が得られる。 Since the compound (B2) having an active ester group has a naphthylene ether structural site in the main molecular skeleton, it can impart better heat resistance and flame retardancy to the cured product, and the structural site has the following structure site

Since it has a structure in which the cured product is bonded with the , it is possible to combine excellent dielectric properties with the cured product. In addition, in the resin structure of the compound having an active ester group of (B2), by having an aryloxy group as a structure at both terminals, the thermal decomposition resistance of the cured product is sufficiently improved even for multilayer printed circuit board applications. is obtained.

The compound (B2) having an active ester group preferably has a softening point in the range of 100 to 200°C, more preferably in the range of 100 to 190°C, because the cured product has excellent heat resistance.

Among the compounds (B2) having an active ester group, m in formula (2) is an integer of 1-6. Among them, those in which m is an integer of 1 to 5 are preferable. Further, each n in the formula (2) is independently an integer of 1 to 5. Among them, those in which n is an integer of 1 to 3 are preferable.
In formula (2), just to mention the relationship between m and n, for example, when m is an integer of 2 or more, n of 2 or more occurs, where each n is an independent value be. As long as they are within the numerical range of n, they may be the same value or different values.

In the compound (B2) having an active ester group, when q is 1 or more in formula (2), X ₂ is substituted at any position in the naphthalene ring structure.

The aryloxy groups at both ends of the resin structure include those derived from monohydric phenolic compounds such as phenol, cresol, pt-butylphenol (para-tert-butylphenol), 1-naphthol and 2-naphthol. Among them, phenoxy, tolyloxy and 1-naphthyloxy are preferred, and 1-naphthyloxy is more preferred, from the viewpoint of thermal decomposition of the cured product.

The method for producing the compound (B2) having an active ester group is described in detail below.
The method for producing a compound having an active ester group (B2) comprises a step of reacting a dihydroxynaphthalene compound and benzyl alcohol in the presence of an acid catalyst to obtain a benzyl-modified naphthalene compound (hereinafter, this step is referred to as "Step 1". ), and then a step of reacting the resulting benzyl-modified naphthalene compound, an aromatic dicarboxylic acid chloride and a monohydric phenolic compound (hereinafter, this step may be abbreviated as “step 2”. There is).

That is, first, in step 1, the dihydroxynaphthalene compound and benzyl alcohol are reacted in the presence of an acid catalyst to obtain a naphthylene structure as a main skeleton having phenolic hydroxyl groups at both ends thereof and the naphthylene structure. A benzyl-modified naphthalene compound having a structure in which a benzyl group is attached to an aromatic nucleus in a pendant form can be obtained. Here, it should be noted that, in general, when a dihydroxynaphthalene compound is naphthylene etherified in the presence of an acid catalyst, it is extremely difficult to control the molecular weight, resulting in a high molecular weight product. By using together, such a high molecular weight increase can be suppressed, and a resin suitable for electronic material applications can be obtained.

Furthermore, by adjusting the amount of benzyl alcohol used, it is possible not only to adjust the content of benzyl groups in the desired benzyl-modified naphthalene compound, but also to adjust the melt viscosity of the benzyl-modified naphthalene compound itself. Become. That is, usually, the reaction ratio between the dihydroxynaphthalene compound and benzyl alcohol is such that the reaction ratio between the dihydroxynaphthalene compound and benzyl alcohol (dihydroxynaphthalene compound)/(benzyl alcohol) on a molar basis is 1/0.1 to 1. /10, but from the balance of heat resistance, flame retardancy, dielectric properties, and thermal decomposition resistance, the reaction ratio of the dihydroxynaphthalene compound and benzyl alcohol on a molar basis (dihydroxynaphthalene compound) /(benzyl alcohol) is preferably in the range of 1/0.5 to 1/4.0.

Dihydroxynaphthalene compounds that can be used here include, for example, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7 -dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene and the like. Among these, 1,6-dihydroxynaphthalene is used because the resulting cured product of the benzyl-modified naphthalene compound has better flame retardancy, and the cured product also has a lower dielectric loss tangent and better dielectric properties. Alternatively, 2,7-dihydroxynaphthalene is preferred, and 2,7-dihydroxynaphthalene is more preferred.

Acid catalysts that can be used in the reaction of the dihydroxynaphthalene compound and benzyl alcohol in step 1 include, for example, inorganic acids such as phosphoric acid, sulfuric acid and hydrochloric acid, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethane Examples include organic acids such as sulfonic acid, Friedel-Crafts catalysts such as aluminum chloride, zinc chloride, stannic chloride, ferric chloride, and diethyl sulfate.

The amount of the acid catalyst used can be appropriately selected according to the target modification rate and the like. 0 part by mass, preferably 0.01 to 3.0 parts by mass, and in the case of a Friedel-Crafts catalyst, 0.2 to 3.0 mol, preferably 0.5 to 3.0 mol, per 1 mol of the dihydroxynaphthalene compound It is preferably in the range of 2.0 mol.

The reaction of the dihydroxynaphthalene compound and benzyl alcohol in step 1 can be carried out without a solvent, or can be carried out in the presence of a solvent in order to improve the uniformity in the reaction system. Examples of such solvents include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monopropyl ether. mono- or diethers of ethylene glycol and diethylene glycol such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether and diethylene glycol monobutyl ether; non-polar aromatic solvents such as benzene, toluene and xylene; non-polar solvents such as dimethylformamide and dimethyl sulfoxide. Protic polar solvents; chlorobenzene and the like.

A specific method for carrying out the reaction of step 1 is to dissolve a dihydroxynaphthalene compound, benzyl alcohol and the acid catalyst in the absence of a solvent or in the presence of the solvent, and It can be carried out under temperature conditions. The reaction time is not particularly limited, but preferably 1 to 10 hours. Therefore, the reaction can be specifically carried out by maintaining the above temperature for 1 to 10 hours. Further, it is preferable to distill off the water generated during the reaction to the outside of the system using a fractionating tube or the like, from the viewpoint of rapid progress of the reaction and improvement of productivity.

In addition, when the resulting benzyl-modified naphthalene compound is highly colored, an antioxidant or reducing agent may be added to the reaction system in order to suppress it. Examples of antioxidants include hindered phenol compounds such as 2,6-dialkylphenol derivatives, divalent sulfur compounds, and phosphite ester compounds containing a trivalent phosphorus atom. Examples of reducing agents include hypophosphorous acid, phosphorous acid, thiosulfuric acid, sulfurous acid, hydrosulfite and salts thereof.

After completion of the reaction, the acid catalyst is removed by neutralization treatment, washing treatment or decomposition, and the desired resin having phenolic hydroxyl groups can be separated by general operations such as extraction and distillation. Neutralization treatment and water washing treatment may be carried out according to conventional methods, and for example, basic substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, triethylenetetramine, and aniline can be used as neutralizing agents.

Here, specific examples of the aromatic dicarboxylic acid chlorides include phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. and acid chlorides of Among them, isophthalic acid chloride and terephthalic acid chloride are preferable from the viewpoint of the balance between solvent solubility and heat resistance.

Specific examples of the monohydric phenol compounds include phenol, cresol, pt-butylphenol, 1-naphthol and 2-naphthol. Among them, phenol, cresol, and 1-naphthol are preferred from the viewpoint of good reactivity with carboxylic acid chloride, and 1-naphthol is more preferred from the viewpoint of good thermal decomposition resistance.

Here, specifically, the method of reacting the benzyl-modified naphthalene compound, the aromatic dicarboxylic acid chloride, and the monohydric phenol compound can be performed by reacting each of these components in the presence of an alkali catalyst.

Alkaline catalysts that can be used here include sodium hydroxide, potassium hydroxide, triethylamine, pyridine, and the like. Among these, sodium hydroxide and potassium hydroxide are particularly preferred because they can be used in the form of an aqueous solution, resulting in good productivity.

Specifically, the reaction can be carried out by mixing the components described above in the presence of an organic solvent and dropping the alkali catalyst or its aqueous solution continuously or intermittently. At that time, the concentration of the aqueous solution of the alkali catalyst is preferably in the range of 3.0 to 30% by mass. Organic solvents that can be used here include toluene, dichloromethane, and chloroform.

After completion of the reaction, when an aqueous solution of an alkali catalyst is used, the reaction solution is allowed to stand for liquid separation, the aqueous layer is removed, and the remaining organic layer is washed until the aqueous layer becomes almost neutral, The target resin can be obtained.

The compound (B2) having an active ester group obtained in this way preferably has a softening point of 100 to 200° C., since it has high solubility in organic solvents.

(curing agent)
The curable resin composition of the present invention may contain (B) a curing agent other than the compound having an active ester group, for example, a compound having a phenolic hydroxyl group, a poly Carboxylic acids and their acid anhydrides, compounds having a cyanate ester group, compounds having a maleimide group, alicyclic olefin polymers, and the like. A compound having a phenolic hydroxyl group is preferable from the viewpoint of adhesion.

Examples of compounds having a phenolic hydroxyl group include phenol novolak resins, alkylphenol borak resins, bisphenol A novolak resins, dicyclopentadiene type phenol resins, Xylok type phenol resins, terpene-modified phenol resins, cresol/naphthol resins, polyvinylphenols, Conventionally known resins such as phenol/naphthol resins, α-naphthol skeleton-containing phenol resins, triazine skeleton-containing cresol novolac resins, biphenylaralkyl-type phenol resins, and Zyloc-type phenol novolac resins can be used.
Among the compounds having a phenolic hydroxyl group, those having a hydroxyl equivalent of 100 g/eq. The above are preferred. A hydroxyl equivalent of 100 g/eq. Examples of compounds having a phenolic hydroxyl group include, for example, dicyclopentadiene skeleton phenol novolac resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), Zyloc-type phenol novolac resin (MEHC-7800, manufactured by Meiwa Kasei Co., Ltd.), and biphenyl aralkyl type. Novolac resin (MEHC-7851, manufactured by Meiwa Kasei Co., Ltd.), naphthol aralkyl type curing agent (SN series, manufactured by Nippon Steel & Sumitomo Metal Corporation), triazine skeleton-containing cresol novolac resin (LA-3018-50P, manufactured by DIC), triazine skeleton-containing phenol A novolac resin (LA-7052, manufactured by DIC Corporation) and the like can be mentioned.

The compound having a cyanate ester group is preferably a compound having two or more cyanate ester groups (--OCN) in one molecule. Any conventionally known compound having a cyanate ester group can be used. Examples of compounds having a cyanate ester group include phenol novolac type cyanate ester resins, alkylphenol novolac type cyanate ester resins, dicyclopentadiene type cyanate ester resins, bisphenol A type cyanate ester resins, bisphenol F type cyanate ester resins, and bisphenol S type. A cyanate ester resin is mentioned. Also, a prepolymer partially triazined may be used.

Examples of commercially available compounds having a cyanate ester group include a phenol novolak type polyfunctional cyanate ester resin (PT30S, manufactured by Lonza Japan Co., Ltd.), and a prepolymer in which part or all of bisphenol A dicyanate is triazined to form a trimer. (BA230S75, manufactured by Lonza Japan), dicyclopentadiene structure-containing cyanate ester resin (DT-4000, DT-7000, manufactured by Lonza Japan).

The compound having a maleimide group is a compound having a maleimide skeleton, and any conventionally known compound can be used. The compound having a maleimide group preferably has two or more maleimide skeletons, such as N,N'-1,3-phenylenedimaleimide, N,N'-1,4-phenylenedimaleimide, N,N'-4 ,4-diphenylmethanebismaleimide, 1,2-bis(maleimido)ethane, 1,6-bismaleimidohexane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, 2,2′-bis- [4-(4-maleimidophenoxy)phenyl]propane, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, bis( At least one of 3-ethyl-5-methyl-4-maleimidophenyl)methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane maleimide, oligomers thereof, and diamine condensates having a maleimide skeleton is more preferred. The oligomer is an oligomer obtained by condensing a compound having a maleimide group, which is a monomer among the compounds having a maleimide group described above.

Examples of commercially available compounds having a maleimide group include BMI-1000 (4,4′-diphenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-2300 (phenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI- 3000 (m-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-5100 (3,3′-dimethyl-5,5′-dimethyl-4,4′-diphenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI -7000 (4-methyl-1,3,-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-TMH ((1,6-bismaleimide-2,2,4-trimethyl) hexane, manufactured by Daiwa Kasei Kogyo Co., Ltd. ) and the like.

The amount of the curing agent other than the compound having an active ester group is preferably, for example, 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, when the nonvolatile component in the resin composition is 100% by mass. preferable.

(Inorganic filler)
The curable resin composition of the invention preferably contains an inorganic filler. By blending the inorganic filler, the curing shrinkage of the resulting cured product is suppressed, the CTE becomes lower, the adhesion, hardness, crack resistance by matching the thermal strength with the conductor layer such as copper around the insulating layer, etc. can improve the thermal properties of Conventionally known inorganic fillers can be used as the inorganic filler, and although not limited to a specific one, examples include silica such as barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay , Neuburg silica particles, boehmite, magnesium carbonate, calcium carbonate, titanium oxide, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, calcium zirconate and other extender pigments, copper, tin, zinc, nickel, silver, palladium , aluminum, iron, cobalt, gold, and platinum. The inorganic filler is preferably spherical particles. Among them, silica is preferable because it suppresses curing shrinkage of the cured product of the curable composition, lowers the CTE, and improves properties such as adhesion and hardness. The average particle size (median size, D50) of the inorganic filler is preferably 0.01 to 10 μm. The inorganic filler is preferably silica having an average particle size of 0.01 to 3 μm from the viewpoint of slit workability. In this specification, the average particle size of the inorganic filler is an average particle size including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates). The average particle size can be obtained with a laser diffraction particle size distribution analyzer. Nanotrac wave manufactured by Nikkiso Co., Ltd., etc., can be used as a measuring device using the laser diffraction method.

The inorganic filler is preferably a surface-treated inorganic filler. As the surface treatment, a surface treatment with a coupling agent, or a surface treatment that does not introduce an organic group, such as alumina treatment, may be performed. The surface treatment method of the inorganic filler is not particularly limited, and a known and commonly used method may be used, and the inorganic filler is treated with a surface treatment agent having a curable reactive group, such as a coupling agent having a curable reactive group as an organic group. surface should be treated.

The surface treatment of the inorganic filler is preferably surface treatment with a coupling agent. As the coupling agent, silane-based, titanate-based, aluminate-based, and zirco-aluminate-based coupling agents can be used. Among them, silane coupling agents are preferred. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-amino propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxy cyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane and the like, and these may be used alone or in combination. can be used These silane-based coupling agents are preferably immobilized in advance on the surface of the inorganic filler by adsorption or reaction. Here, the processing amount of the coupling agent with respect to 100 parts by mass of the inorganic filler is, for example, 0.5 to 10 parts by mass.

A thermosetting reactive group is preferred as the curable reactive group. Thermosetting reactive groups include hydroxyl group, carboxyl group, isocyanate group, amino group, imino group, epoxy group, oxetanyl group, mercapto group, methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, oxazoline group, etc. is mentioned. Among them, at least one of an amino group and an epoxy group is preferable. The surface-treated inorganic filler may have a photocurable reactive group in addition to the thermosetting reactive group.

In addition, the surface-treated inorganic filler may be contained in the curable resin composition in a surface-treated state, and the inorganic filler and the surface treatment agent are separately blended into the curable resin composition. Although the inorganic filler may be surface-treated in the product, it is preferable to incorporate an inorganic filler that has been surface-treated in advance. By blending the inorganic filler which has been surface-treated in advance, it is possible to prevent deterioration of crack resistance and the like caused by the surface-treating agent not consumed in the surface treatment, which may remain when blended separately. When surface treatment is performed in advance, it is preferable to blend a preliminary dispersion in which an inorganic filler is pre-dispersed in a solvent or a curable resin. Alternatively, it is more preferable that the surface-untreated inorganic filler is sufficiently surface-treated when pre-dispersed in a solvent, and then the pre-dispersed liquid is added to the composition.

The inorganic filler may be blended with the epoxy resin or the like in a powder or solid state, or may be blended with the epoxy resin or the like after being mixed with a solvent or dispersant to form a slurry.

An inorganic filler may be used individually by 1 type, and may be used as a mixture of 2 or more types. When the non-volatile component in the resin composition is 100% by mass, the amount of the inorganic filler is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 65% by mass or more from the viewpoint of lowering the CTE. preferable. From the viewpoint of the toughness of the cured film, it is preferably 90% by mass or less, more preferably 85% by mass or less.

(Curing accelerator)
The curable resin composition of the present invention can contain a curing accelerator. The curing accelerator accelerates the thermosetting reaction and is used to further improve properties such as adhesion, chemical resistance and heat resistance. Specific examples of such curing accelerators include imidazole and its derivatives; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, polyamines such as melamine and polybasic hydrazides; organic acid salts and/or epoxy adducts thereof; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4- Triazine derivatives such as diamino-6-xylyl-S-triazine; trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, dimethylaminopyridine, N-methylmorpholine, hexa(N- amines such as methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, and alkylphenol novolak; tributylphosphine , triphenylphosphine, tris-2-cyanoethylphosphine and other organic phosphines; tri-n-butyl (2,5-dihydroxyphenyl)phosphonium bromide, hexadecyltributylphosphonium chloride and other phosphonium salts; benzyltrimethylammonium chloride, phenyltributyl Quaternary ammonium salts such as ammonium chloride; polybasic acid anhydrides; photocationic polymerization of diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate, etc. Catalyst; styrene-maleic anhydride resin; equimolar reaction products of phenyl isocyanate and dimethylamine, equimolar reaction products of organic polyisocyanates such as tolylene diisocyanate and isophorone diisocyanate and dimethylamine, conventionally known curing accelerators such as metal catalysts agents. Among the curing accelerators, imidazole and its derivatives, and dimethylaminopyridine are preferable, and imidazole and its derivatives are more preferable because a cured product having a higher Tg and a lower dielectric loss tangent can be obtained.

A hardening accelerator can be used individually by 1 type or in mixture of 2 or more types. The amount of the curing accelerator is preferably 5% by mass or less, preferably 3% by mass or less, from the viewpoint of the storage stability of the resin composition before the thermosetting reaction, when the nonvolatile component in the resin composition is 100% by mass. is more preferable, and from the viewpoint of curability, 0.01% by mass or more is preferable, and 0.1% by mass or more is more preferable.

(Thermoplastic resin (polymer resin))
The curable resin composition of the present invention may further contain a thermoplastic resin in order to improve the mechanical strength of the resulting cured film. The thermoplastic resin is preferably soluble in solvents. When it is soluble in a solvent, the flexibility is improved when it is made into a dry film, and the occurrence of cracks and falling powder can be suppressed. Thermoplastic resins include thermoplastic polyhydroxy polyether resins, phenoxy resins that are condensates of epichlorohydrin and various bifunctional phenol compounds, and various acid anhydrides and acid chlorides that replace the hydroxyl groups of the hydroxy ether portion present in the skeleton. and esterified phenoxy resins, polyvinyl acetal resins, polyamide resins, polyamideimide resins, block copolymers, and the like. Thermoplastic resins can be used singly or in combination of two or more. Among these thermoplastic resins, phenoxy resins are preferable because they can improve the glass transition temperature while maintaining a low dielectric loss tangent. Polyvinyl acetal resin is preferable from the viewpoint of reducing the roughness of the cured product surface after desmearing.

The polyvinyl acetal resin can be obtained, for example, by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and examples include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, Examples include methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde and the like, with butyraldehyde being preferred.

Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Tohto Kasei Co., Ltd., and YX8100, YX6954, YL6954, YL6974 and YX7200 manufactured by Mitsubishi Chemical Corporation. Further, specific examples of polyvinyl acetal resins include S-lec KS series manufactured by Sekisui Chemical Co., Ltd., polyamide resins include KS5000 series manufactured by Hitachi Chemical Co., Ltd., BP series manufactured by Nippon Kayaku Co., Ltd., and polyamideimide resins. KS9000 series manufactured by Hitachi Chemical Co., Ltd. can be mentioned. The blending amount of the thermoplastic resin is, when the total of (A) the epoxy resin and (B) the compound having an active ester group in the resin composition is 100% by mass, from the viewpoint of the mechanical strength of the resulting cured film. , is preferably 0.1% by mass or more, more preferably 0.3% by mass or more. From the viewpoint of the dielectric properties of the cured film, it is preferably 30% by mass or less, more preferably 20% by mass or less.

(rubber-like particles)
The curable resin composition of the present invention can contain rubber-like particles as necessary. Examples of such rubbery particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl group-modified polybutadiene rubber, carboxyl group- or hydroxyl group-modified acrylonitrile-butadiene rubber, and These crosslinked rubber particles, core-shell type rubber particles and the like can be mentioned, and one type can be used alone or two or more types can be used in combination. These rubber-like particles are added to improve the flexibility of the resulting cured film, improve the crack resistance, enable surface roughening treatment with an oxidizing agent, and improve the adhesion strength to copper foil, etc. be done.

The average particle size of the rubber-like particles is preferably in the range of 0.005-15 μm, more preferably in the range of 0.2-10 μm. The average particle size of the rubber-like particles in the present invention can be determined with a laser diffraction particle size distribution analyzer. For example, the rubber-like particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves or the like, and the particle size distribution of the rubber-like particles is prepared on a mass basis using a Nanotrac wave manufactured by Nikkiso Co., Ltd. The median diameter is taken as the average particle diameter. can be measured by

(Flame retardants)
The curable resin composition of the present invention can contain a flame retardant. Flame retardants include hydrated metals such as aluminum hydroxide and magnesium hydroxide, red phosphorus, ammonium phosphate, ammonium carbonate, zinc borate, zinc stannate, molybdenum compounds, bromine compounds, chlorine compounds, and phosphate esters. , phosphorus-containing polyols, phosphorus-containing amines, melamine cyanurate, melamine compounds, triazine compounds, guanidine compounds, silicone polymers and the like. A flame retardant can be used individually by 1 type or in combination of 2 or more types.

(Organic solvent)
The organic solvent is not particularly limited, but examples include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. can. More specifically, ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol , butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether and other glycol ethers; Esters such as ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate; ethanol, propanol, 2- Alcohols such as methoxypropanol, n-butanol, isobutyl alcohol, isopentyl alcohol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum oils such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha In addition to system solvents, N,N-dimethylformamide (DMF), tetrachlorethylene, turpentine oil and the like can be used. In addition, Swazol 1000 and Swazol 1500 manufactured by Maruzen Petrochemical Co., Ltd., Solvesso 100 and Solvesso 150 manufactured by Standard Oil Osaka Co., Ltd., Solvent #100 and Solvent #150 manufactured by Sankyo Chemical Co., Ltd., Shell Sol A100 and Shell Sol A150 manufactured by Shell Chemicals Japan Co., Ltd. , Ipsol No. 100 and Ipsol No. 150 manufactured by Idemitsu Kosan Co., Ltd. may also be used. An organic solvent can be used individually by 1 type or in combination of 2 or more types.

When dry film is formed, the amount of residual solvent in the resin layer is preferably 0.5 to 10.0% by mass. When the residual solvent content is 10.0% by mass or less, bumping during thermosetting is suppressed, and the flatness of the surface becomes better. In addition, it is possible to prevent the resin from flowing due to an excessive decrease in melt viscosity, thereby improving flatness. When the residual solvent is 0.5% by mass or more, the fluidity during lamination is good, and the flatness and embedding properties are further improved.

(other ingredients)
The curable resin composition of the present invention may further optionally contain an organic filler such as silicon powder, fluorine powder, nylon powder, phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, Conventionally known colorants such as carbon black and naphthalene black; conventionally known thickeners such as asbestos, orben, bentone, and finely divided silica; antifoaming agents and/or leveling agents such as silicone-based, fluorine-based, and polymer-based agents; , thiazole-based, triazole-based, silane coupling agents and other adhesion imparting agents, titanate-based and aluminum-based conventionally known additives can be used.

The curable resin composition of the present invention may be used as a dry film or as a liquid. When used as a liquid, it may be one-liquid or two-liquid or more, but from the viewpoint of storage stability, it is preferably two-liquid or more.

[Dry film]
The dry film of the present invention can be produced by applying the curable resin composition of the present invention onto a carrier film and drying to form a resin layer as a dry coating film. A protective film can be laminated on the resin layer, if necessary.

The carrier film has a role of supporting the resin layer of the dry film, and is a film to which the curable resin composition is applied when forming the resin layer. Examples of carrier films include thermoplastic resin films such as polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polyethylene films, polytetrafluoroethylene films, polypropylene films, and polystyrene films, and Surface-treated paper or the like can be used. Among these, a polyester film can be preferably used from the viewpoint of heat resistance, mechanical strength, handleability, and the like. The thickness of the carrier film is not particularly limited, but is appropriately selected in the range of approximately 10 to 150 μm depending on the application. A releasing treatment may be applied to the surface of the carrier film on which the resin layer is to be provided. Sputtering or ultra-thin copper foil may be formed on the surface of the carrier film on which the resin layer is to be formed.

The protective film is provided on the surface of the resin layer opposite to the carrier film for the purpose of preventing dust from adhering to the surface of the resin layer of the dry film and improving handleability. As the protective film, for example, a film made of a thermoplastic resin exemplified for the carrier film, a surface-treated paper, or the like can be used. Among these, a polyester film, a polyethylene film, and a polypropylene film are preferable. The thickness of the protective film is not particularly limited, but is appropriately selected in the range of approximately 10 to 150 μm depending on the application. A release treatment may be applied to the surface of the protective film on which the resin layer is provided.

[Copper foil coated with resin]
The resin-coated copper foil of the present invention has a resin layer obtained by coating the curable resin composition of the present invention on a copper foil or an ultra-thin copper foil with a carrier, followed by drying.

The copper foil may be electrolytic copper foil or rolled copper foil. The thickness is usually 250 μm or less, preferably 9-200 μm. The surface to be coated with the curable resin composition is preferably roughened with copper chloride or the like so as to improve the adhesion between the copper foil and the resin layer.

The method of forming the ultra-thin copper foil is not particularly limited, and may be formed by a wet film forming method such as an electroless copper plating method or an electrolytic copper plating method, a dry film forming method such as sputtering or chemical vapor deposition, or a combination thereof. can be done. The thickness of the ultra-thin copper foil is preferably 0.1-7.0 μm, more preferably 0.5-5.0 μm, even more preferably 1.0-3.0 μm.

The ultra-thin copper foil with a carrier may have a structure in which the carrier foil and the ultra-thin copper foil are provided in this order, and the resin layer made of the curable resin composition of the present invention is laminated so as to be in contact with the ultra-thin copper foil. It is good if there is

Examples of the carrier foil include copper foil, aluminum foil, stainless steel (SUS) foil, and a resin film having a metal-coated surface. Copper foil is preferred. The copper foil may be electrolytic copper foil or rolled copper foil. The thickness of the carrier foil is usually 250 μm or less, preferably 9-200 μm. A release layer may be formed between the carrier foil and the ultra-thin copper foil, if necessary.

The method of forming the ultra-thin copper foil is not particularly limited, and may be formed by a wet film forming method such as an electroless copper plating method or an electrolytic copper plating method, a dry film forming method such as sputtering or chemical vapor deposition, or a combination thereof. can be done. The thickness of the ultra-thin copper foil is preferably 0.1-7.0 μm, more preferably 0.5-5.0 μm, even more preferably 1.0-3.0 μm.

[Prepreg]
The prepreg of the present invention is obtained by coating and/or impregnating a sheet-like fibrous base material with the curable resin composition of the present invention, followed by drying. Examples of the sheet-like fibrous base material include glass cloth, glass, and aramid nonwoven fabric.

As a method for producing an electronic component using the curable resin composition of the present invention, a conventionally known method may be used. The method for curing the curable resin composition of the present invention is not particularly limited, and may be cured by a conventionally known method, for example, curing by heating at 150 to 230°C. As a method for producing a printed wiring board using the curable resin composition of the present invention, for example, in the case of a dry film having a three-layer structure in which a resin layer is sandwiched between a carrier film and a protective film, the following A printed wiring board can be manufactured by the method. Either the carrier film or the protective film is peeled off from the dry film, heat-laminated to a circuit board having a circuit pattern formed thereon, and then heat-cured. For heat curing, curing may be performed in an oven or using a hot plate press. When the circuit-formed substrate and the dry film of the present invention are laminated or hot-plate-pressed, the copper foil or the circuit-formed substrate can be laminated at the same time. A printed wiring board can be manufactured by forming patterns and via holes by laser irradiation or drilling at positions corresponding to predetermined positions on a board on which a circuit pattern is formed and exposing the circuit wiring. At this time, if there is a residual component (smear) that cannot be completely removed on the pattern or the circuit wiring in the via hole, desmear processing is performed. The remaining carrier film or protective film may be peeled off after lamination, after heat curing, after laser processing, or after desmearing. Note that a method of connecting the interlayer circuits may be a connection using a copper pillar.

Further, when producing a printed wiring board using the resin-coated copper foil of the present invention, the resin layer is laminated on a circuit board on which a circuit pattern is formed, and a subtractive process or an ultra-thin copper foil is applied to all or all of the wiring layers. A circuit may be partially formed by a modified semi-additive process (MSAP) method to manufacture a build-up wiring board. Alternatively, a build-up wiring board may be manufactured by removing the ultra-thin copper foil and forming a circuit by a semi-additive process (SAP) method. Alternatively, a printed wiring board may be manufactured by direct build-up on wafer, in which lamination of resin-coated copper foil on a semiconductor integrated circuit and circuit formation are alternately repeated. Alternatively, a coreless build-up method in which resin layers and conductor layers are alternately laminated may be used without using a core substrate.

The curable resin composition of the present invention can be preferably used for forming a permanent protective film for electronic parts, particularly for printed wiring boards, and is particularly preferred for forming solder resist layers, interlayer insulating layers, and coverlays for flexible printed wiring boards. can be used. Moreover, it can be suitably used for permanent hole filling of printed wiring boards, for example, hole filling such as through holes and via holes. It can also be used as a sealing material for semiconductor chips, as a material for copper clad laminates (CCL) and prepregs. Since the cured product of the curable resin composition of the present invention has excellent dielectric properties, it can be suitably used for high frequency applications where transmission loss is a problem. Specific examples of high-frequency applications include substrates for millimeter-wave radar and millimeter-wave sensors for autonomous driving, motherboards for mobile devices supporting high-speed communication, and SLP (Substrate-Like PCB) that forms circuits using the modified semi-additive process (MSAP) method. ), application processors (AP) for mobile and personal computers, HDI (High Density Interconnect) substrates and PKG (Package) substrates for smartphones, tablets and personal computers, multi-layer substrates for servers and routers for base stations, substrates for antennas and semiconductors sealing materials, and the like. A wiring board may be formed by bonding wiring using the dry film of the present invention. Electronic components may be used for applications other than printed wiring boards, such as passive components such as inductors.

The form of the circuit forming material using the curable resin composition of the present invention is a resin-coated copper foil (RCC) compatible with a subtractive process or a modified semi-additive process (MSAP) or a semi-additive process ( It may be a build-up film compatible with SAP).

Although the dielectric loss tangent of the cured product of the present invention is not particularly limited, it is possible to obtain a cured product with a low dielectric loss tangent according to the present invention, for example, 0.005 or less, further 0.003 or less, or It is also possible to set it to 0.002 or less.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention, but it goes without saying that the present invention is not limited to the following Examples. In the following description, "parts" and "%" are based on mass unless otherwise specified.

<Synthesis of compound having active ester group>
(Synthesis Example 1: Synthesis of a compound having an active ester group (B-1))
A flask equipped with a thermometer, a dropping funnel, a condenser, a fractionating tube, and a stirrer was charged with 203.0 g of isophthaloyl chloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene, and the system was decompressed and replaced with nitrogen. and dissolved. Next, 96.0 g (0.67 mol) of α-naphthol and 220 g of dicyclopentadiene phenol resin (number of moles of phenolic hydroxyl group: 1.33 mol) were added, and the system was decompressed and replaced with nitrogen to dissolve. Thereafter, 1.12 g of tetrabutylammonium bromide was dissolved, and while purging with nitrogen gas, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours.
Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by decanter dehydration to obtain an active ester resin (B-1) in the form of a toluene solution having a non-volatile content of 65%. The obtained active ester resin (B-1) had an ester group equivalent in terms of solid content of 223 g/eq. Met.

(Synthesis Example 2: Synthesis of a compound having an active ester group (B-2))
A flask equipped with a thermometer, a dropping funnel, a condenser, a fractionating tube, and a stirrer was charged with 320 g (2.0 mol) of 2,7-dihydroxynaphthalene, 184 g (1.7 mol) of benzyl alcohol, p-toluenesulfonic acid and 5.0 g of monohydrate was charged and stirred at room temperature while blowing nitrogen. After that, the temperature was raised to 150° C., and the mixture was stirred for 4 hours while distilling out the water produced. After completion of the reaction, 900 g of methyl isobutyl ketone and 5.4 g of 20% aqueous sodium hydroxide solution were added for neutralization, and then the aqueous layer was removed by liquid separation and washed with 280 g of water three times to remove methyl isobutyl ketone under reduced pressure. After removal, 460 g of a benzyl-modified naphthalene compound (B-2 intermediate) was obtained. The resulting benzyl-modified naphthalene compound (B-2 intermediate) was a black solid and had a hydroxyl equivalent of 180 g/eq. Met.
A flask equipped with a thermometer, a dropping funnel, a condenser, a fractionating tube, and a stirrer was charged with 203.0 g of isophthaloyl chloride (moles of acid chloride group: 2.0 mol) and 1400 g of toluene, and the system was evacuated. It was dissolved under nitrogen substitution. Next, 96.0 g (0.67 mol) of α-naphthol and 240 g of benzyl-modified naphthalene compound (B-2 intermediate) (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen. Dissolved. Thereafter, 0.70 g of tetrabutylammonium bromide was dissolved, and while purging with nitrogen gas, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, water was added to the toluene layer in which the reactants were dissolved, and the mixture was stirred and mixed for 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by decanter dehydration to obtain an active ester resin (B-2) in the form of a toluene solution having a non-volatile content of 65% by mass. The obtained active ester resin (B-2) had an ester group equivalent weight of 230 g/eq. Met.

<Preparation of curable resin composition>
Various components shown in Examples and Comparative Examples in Table 1 below were kneaded and mixed at the ratios (parts by mass) shown in Table 1 to prepare a curable resin composition for film production after curing. In addition, the numerical value in a table|surface shows a mass part (non-volatile content conversion).

<Preparation of film after curing>
Using a film applicator, the curable resin composition was applied to the glossy surface of a copper foil (F2-WS manufactured by Furukawa Electric Co., Ltd., 18 μm thick) for each example and comparative example, and dried at 90°C in a hot air circulation drying oven. C. for 10 minutes, followed by curing at 200.degree.

<Measurement of glass transition temperature (Tg) and coefficient of linear thermal expansion (CTE (α1))>
The sample obtained in <Preparation of film after curing> was cut into a measurement size (3 mm x 10 mm size), and the glass transition temperature (Tg) was measured using TMA Q400EM manufactured by TA Instruments. . The temperature was raised from room temperature at a heating rate of 10 ° C./min, and the measurement was performed twice in succession. .
◎: 175 ° C. or higher ○: 175 ° C. or lower 170 ° C. or higher ×: 170 ° C. or lower

<Measurement of dielectric loss tangent (Df)>
The sample obtained in <Preparation of film after curing> was cut into a measurement size (size of 50 mm × 60 mm), and an SPDR dielectric resonator and network analyzer (both manufactured by Agilent) were used to measure the dielectric loss tangent of 10 GHz at 23 ° C. was measured and evaluated according to the following criteria.
◎: less than 0.003 ○: 0.003 or more and less than 0.010 ×: 0.010 or more

<Preparation of sample for peel strength measurement>
(1) Roughening Treatment of Laminate Both sides of a glass cloth base epoxy resin double-sided copper-clad laminate [copper foil thickness 18 μm, substrate thickness 0.3 mm, R5715ES manufactured by Panasonic Corporation] on which an inner layer circuit is formed are treated by MEC Co., Ltd. The copper surface was roughened (etching amount: about 1 μm) by immersing it in CZ8100 manufactured by the company.
(2) Preparation of resin-coated copper foil Using a film applicator, a curable resin composition was applied to each example and comparative example. It was applied on the thin copper foil surface and dried at 90° C. for 10 minutes in a hot air circulation drying oven to obtain a resin-coated copper foil having a resin layer thickness of about 40 μm.
(3) Lamination of resin-coated copper foil Using a batch-type vacuum pressure laminator MVLP-500 (manufactured by Meiki Seisakusho, trade name), on both sides of the laminate subjected to roughening treatment (1), resin-coated copper The resin composition-coated surface of the foil (2) was laminated. Lamination was carried out by reducing the pressure to 13 hPa or less for 30 seconds and then pressing for 30 seconds at 80° C. and a pressure of 0.5 MPa.
(4) Curing of Resin Composition The laminate (3) laminated with the resin-coated copper foil was cured at 170° C. for 30 minutes in a hot air circulating drying oven.
(5) Electrolytic Copper Plating After curing, the carrier copper foil was peeled off from both sides of the laminate, and the ultra-thin copper foil (3 μm) on both sides was made approximately 25 μm thick by electrolytic copper plating.
(6) Annealing Treatment The laminated plate after electrolytic copper plating was annealed at 200° C. for 60 minutes in a hot air circulating drying furnace.

<Measurement of peel strength>
Using the samples produced by the above method, measurements were made according to JIS C6481 and evaluated according to the following criteria.
◎: 0.6 kN/m or more ○: less than 0.6 kN/m 0.4 kN/m or more ×: less than 0.4 kN/m

*1: EXA-4816 manufactured by DIC Corporation (Bisphenol A type epoxy resin represented by the above formula (5), semi-solid, epoxy equivalent: 400 g/eq.)
*2: EXA-4850-150 manufactured by DIC Corporation (Bisphenol A type epoxy resin represented by the above formula (5), liquid, epoxy equivalent: 450 g/eq.)
*3: EXA-835LV manufactured by DIC Corporation (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, liquid, epoxy equivalent: 165 g/eq.)
* 4: jER1001 manufactured by Mitsubishi Chemical Corporation (bisphenol A type epoxy resin, solid, epoxy equivalent: 470 g / eq.)
* 5: NC-3000H manufactured by Nippon Kayaku Co., Ltd. (biphenyl aralkyl type epoxy resin, solid, epoxy equivalent: 290 g / eq.)
*6: Active ester resin B-1 synthesized in Synthesis Example 1 above (active ester equivalent: 223 g/eq.)
*7: Active ester resin B-2 synthesized in Synthesis Example 2 above (active ester equivalent: 230 g/eq.)
* 8: TD-2090 manufactured by DIC (phenol novolac, hydroxyl equivalent: 105 g / eq.)
*9: Phenylaminosilane-treated SO-C2 manufactured by Admatechs (spherical silica, average particle size: 0.5 μm)
* 10: Mitsubishi Chemical jER YX6954BH30 (phenoxy resin)
* 11: 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Co., Ltd.
*12: Ratio of total amount of epoxy groups of (A) epoxy resin/total amount of active ester groups of compound having (B) active ester groups in the composition

From the results shown in the above table, it can be seen that the curable resin compositions of Examples can provide cured products having high heat resistance, high adhesion, and low dielectric loss tangent.

Claims (9)

A composition containing (A) an epoxy resin and (B) a compound having an active ester group,
As the (A) epoxy resin, (A1) an epoxy equivalent of 350 to 1000 g/eq. liquid or semi-solid epoxy resin,
Curing characterized in that the ratio of the total amount of epoxy groups of the (A) epoxy resin/the total amount of active ester groups of the (B) compound having an active ester group in the composition is 0.2 to 0.6. curable resin compositions (excluding curable resin compositions containing (meth)acrylic acid esters) . The (B) compound having an active ester group is represented by the following general formula (1)

(Wherein, X ₁ is a group having a benzene ring or a naphthalene ring, k represents 0 or 1, and n is an average repeating unit of 0.25 to 1.5.) The curable resin composition according to claim 1, characterized in that The (B) compound having an active ester group is represented by the following general formula (2)

(In formula (2), each of X ₂ is independently represented by the following formula (3):

or the following formula (4):

is a group represented by
m is an integer of 1 to 6, n is each independently an integer of 1 to 5, q is each independently an integer of 0 to 6,
In formula (3), k is each independently an integer of 1 to 5,
In formula (4), Y is a group represented by formula (3) above (k is independently an integer of 1 to 5), and t is independently an integer of 0 to 5)
2. The curable resin composition according to claim 1, wherein the curable resin composition is an active ester resin having a resin structure having a structural site represented by and both ends of which are monovalent aryloxy groups. The epoxy resin (A1) is represented by the following general formula (5)

(In formula (5), R ₁ is a divalent organic group having 6 to 50 carbon atoms containing an aromatic ring, R ₂ is a divalent organic group having 2 to 50 carbon atoms, and m is 1 to 50 n is an integer of 0 to 50, and l is an integer of 0 to 20.) The compound according to any one of claims 1 to 3, wherein A curable resin composition. A dry film comprising a resin layer obtained by applying the curable resin composition according to any one of claims 1 to 4 to a film and drying the composition. A resin-coated copper foil comprising a resin layer obtained by applying the curable resin composition according to any one of claims 1 to 4 to a copper foil or an ultrathin copper foil with a carrier and drying the composition. A prepreg obtained by coating and/or impregnating a sheet-like fibrous base material with the curable resin composition according to any one of claims 1 to 4, followed by drying. The curable resin composition according to any one of claims 1 to 4, the resin layer of the dry film according to claim 5, the resin layer of the resin-coated copper foil according to claim 6, or the resin layer of claim 7. A cured product obtained by curing a prepreg. An electronic component comprising the cured product according to claim 8 .