JP2021017467A - Curable resin composition, dry film, copper foil with resin, prepreg, cured product, and electronic component - Google Patents

Abstract

To provide a curable resin composition and the like capable of giving a cured product combining high heat resistance, high adhesion and a low dielectric loss tangent.SOLUTION: The curable resin composition contains (A) an epoxy resin and (B) a compound having active ester groups. The composition contains (A1) a liquid or semisolid epoxy resin having an epoxy equivalent of 350-1,000 g/eq. as the epoxy resin (A). The ratio of the total amount of epoxy groups of the epoxy resin (A) to the total amount of the active ester groups of the compound (B) having the active ester groups in the composition is 0.2-0.6.SELECTED DRAWING: None

Description

The present invention relates to curable resin compositions, dry films, copper foils with resins, prepregs, cured products, and electronic components.

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

Japanese Patent No. 5396805

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

Therefore, an object of the present invention is to obtain a curable resin composition capable of obtaining a cured product having high heat resistance, high adhesion and low dielectric normal contact, a dry film having a resin layer obtained from the composition, and the composition. A resin-coated copper foil having a resin layer obtained, a prepreg obtained from the composition, the composition, a resin layer of the dry film, a resin layer of the resin-attached copper foil or a cured product of the prepreg, and the cured product. Is to provide an electronic component having the above.

It is conceivable to add a compound having an active ester group as a curing agent in order to reduce the dielectric constant contact. However, in general, when a large amount of a compound having an active ester group is added, the crosslink density of the cured product decreases. It is considered that the glass transition temperature (Tg) of the cured product is lowered and the heat resistance is deteriorated. Normally, a compound having an active ester group excessively exceeding the epoxy equivalent of the epoxy resin in the composition was not blended. .. Further, in general, a cured product having a high glass transition temperature (Tg) has a low peel strength, so that it is difficult to achieve both a glass transition temperature (Tg) and adhesion. However, as a result of diligent studies toward the realization of the above object, the present inventors unexpectedly blended a compound having an active ester group in a specific amount exceeding the epoxy equivalent of the epoxy resin, and also specified a specific compound. It has been found that a cured product having a high glass transition temperature (Tg) and excellent adhesion and dielectric properties can be obtained by blending an epoxy equivalent of a liquid or semi-solid epoxy resin, and has completed 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, and the (A) epoxy resin is (A1) epoxy. Equivalent amount is 350-1000 g / eq. The ratio of the total amount of epoxy groups of the (A) epoxy resin to the total amount of active ester groups of the compound having the (B) active ester group in the composition containing the liquid or semi-solid epoxy resin of It is characterized by being 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 having the active ester group (B) is the following general formula (1).

(In the formula, X ₁ is a group having a benzene ring or a naphthalene ring, k represents 0 or 1, and n is an average of 0.25 to 1.5 in repeating units.) It is preferable to have.

（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 having the active ester group (B) is the following general formula (2).

(In equation (2), X ₂ is independently the following equation (3):

Group represented by or the following formula (4):

It is a group represented by
m is an integer of 1 to 6, n is an integer of 1 to 5 independently, and q is an integer of 1 to 6 independently.
In equation (3), k is an integer of 1 to 5 independently.
In the formula (4), Y is a group represented by the above formula (3) (k is an integer of 1 to 5 independently), and t is an integer of 0 to 5 independently).
It is preferable that the active ester resin has a structural portion represented by, and has a resin structure in which both ends thereof 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 of the above (A1) is the following general formula (5).

(In the formula (5), R ₁ is a divalent organic group having 6 to 50 carbon atoms including 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 applying the curable resin composition to the film and drying it.

The resin-containing 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 ultrathin copper foil with a carrier and drying it.

The prepreg of the present invention is characterized in that the curable resin composition is applied to and / or impregnated with a sheet-like fibrous base material and dried.

The cured product of the present invention is characterized by being obtained by curing the curable resin composition, the resin layer of the dry film, the resin layer of the copper foil with resin, 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 capable of obtaining a cured product having high heat resistance, high adhesion and low dielectric adduct, a dry film having a resin layer obtained from the composition, and the same composition. A resin-coated copper foil having a resin layer, a prepreg obtained from the composition, the composition, a resin layer of the dry film, a 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 to have.

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, and has (A1) an epoxy equivalent as the (A) epoxy resin. 350-1000 g / eq. A compound containing the liquid or semi-solid epoxy resin (hereinafter, also referred to as "(A1) epoxy resin") and having the total amount of epoxy groups of the (A) epoxy resin in the composition / the active ester group of the (B). The ratio of the total amount of active ester groups in the above is 0.2 to 0.6. As described above, it is considered that the heat resistance deteriorates when a large amount of a compound having an active ester group is blended as a curing agent, and it is considered difficult to achieve both the glass transition temperature (Tg) and the adhesion. According to the invention, surprisingly, 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 proportion of the compound having an active ester group, preferably the compound having an active ester group having the structure of the above general formula (1) or (2) is increased, the structure of the active ester, that is, It is considered that the glass transition temperature was improved because the movement of the chain portion between the cross-linking points was controlled by increasing the volume ratio of the aromatic ester structure having high rigidity and high molecular orientation. Further, in the composition in which the proportion of the compound having an active ester group is large as described above, the toughness is improved by blending the epoxy resin having a relatively high epoxy equivalent among the liquid or semi-solid epoxy resins, and the inside of the cured product is improved. It is considered that the fracture was suppressed, the peel strength was improved, and the glass transition temperature (Tg) and the adhesion were compatible with each other.

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

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

Further, in the present invention, the ratio of the total amount of epoxy groups of the (A1) epoxy resin to the total amount of active ester groups of the compound having the (B) active ester group is preferably 0.5 or less. It is more preferably 4 or less. Further, since the glass transition temperature (Tg) becomes better, it is preferably 0.3 or less, more preferably 0.2 or less, and on the other hand, the adhesion becomes better, so it is 0. It is preferably .001 or more, and more preferably 0.01 or more.

Hereinafter, each component contained in the curable resin composition of the present invention will be described. In addition, in this specification, when a numerical range is expressed by "~", it means a range including those numerical values (that is, ... or more ... or less).

[(A) Epoxy resin]
The curable resin composition of the present invention has (A1) an epoxy equivalent of 350 to 1000 g / eq as the (A) epoxy resin. Contains liquid or semi-solid epoxy resin. Here, the epoxy resin is a resin having an epoxy group, and examples thereof include a bifunctional epoxy resin having two epoxy groups in the molecule and a polyfunctional epoxy resin having a large number of epoxy groups in the molecule. It may be a hydrogenated bifunctional epoxy resin. In the present specification, the liquid epoxy resin means a liquid epoxy resin at 20 ° C., and the semi-solid epoxy resin means an epoxy resin which is solid at 20 ° C. and liquid at 40 ° C. The solid epoxy resin described later refers to an epoxy resin that is solid at 40 ° C. Judgment of liquidity is carried out in accordance with the "Liquid Confirmation Method" of Attachment 2 of the Ministerial Ordinance on Dangerous Goods Testing and Properties (Ministerial Ordinance No. 1 of 1989). For example, the method described in paragraphs 23 to 25 of JP-A-2016-079384 is used.

The epoxy resin (A1) is preferably a bifunctional epoxy resin. If it is a bifunctional epoxy resin, the adhesion is improved. The epoxy resin (A1) is more preferably a compound represented by the following general formula (5), for example.

（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 the formula (5), R ₁ is a divalent organic group having 6 to 50 carbon atoms including 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 from 0 to 50, and l is an integer from 0 to 20.)

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

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

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

In the formula (5), the carbon number of the divalent organic group which is a R ₂ is preferably 2 to 40. Divalent organic group which is a R ₂ preferably includes an aliphatic group, a divalent group "-O-CH 2 _-" It is further preferred that an aliphatic group having. Further, 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, and is, for example, a methylene group, a methylmethylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, or a penta. Examples thereof include a methylene group, a hexamethylene group, a heptamethylene group and an octamethylene group.

Divalent organic group which is a R ₂ is more preferably a group represented by the following general formula (6) or (7).

In formulas (6) and (7), R ₃ is a divalent organic group represented by the following formula (8).

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

Further, in the formula (5), m is preferably an integer of 1 to 10. When a plurality of compounds having different m are contained, it is preferable to contain the most compounds in which m is an integer of 1 to 10. Further, in the formula (5), n is preferably an integer of 0 to 10. When a plurality of compounds having different ns are contained, it is preferable to contain the most compounds in which n is an integer of 0 to 10. In formula (5), l is preferably an integer of 0-5. When a plurality of compounds having different l are contained, it is preferable to contain the most compounds in which l is an integer of 0 to 5.

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

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 equation, k is an integer of 0 to 50, preferably an integer of 0 to 10, and more preferably an integer of 0 to 5. (A1) The epoxy resin may be a mixture having a different k value. The average value of the k values is preferably 0.5 to 3.

As the (A1) epoxy resin, the epoxy resin shown in (9) or (10) above is preferable, and examples of commercially available products thereof include EXA-4816, EXA-4850-150, and EXA-4850- manufactured by DIC Corporation. 1000 and the like can be mentioned.

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

As the epoxy resin (A1), one type may be used alone, or two or more types may be used in combination. The blending amount of the epoxy resin (A1) 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. Above all, it is preferable to contain a solid epoxy resin. The (A2) epoxy resin may be a liquid or semi-solid epoxy resin.

Examples of the solid epoxy resin include a tetrafunctional naphthalene type epoxy resin such as HP-4700 manufactured by DIC, a naphthalene skeleton-containing novolac type epoxy resin such as NC-7000 manufactured by Nippon Kayaku Co., Ltd., and ESN-475V manufactured by Nittetsu Chemical & Materials Co., Ltd. Naftor aralkyl type epoxy resin such as, Nippon Kayaku Co., Ltd. EPPN-502H and other phenols and a condensate of aromatic aldehyde having a phenolic hydroxyl group (trisphenol type epoxy resin), DIC Co., Ltd. Epicron HP- Dicyclopentadiene type epoxy resin such as 7200H; Biphenyl aralkyl type epoxy resin such as NC-3000H and NC-3000L manufactured by Nippon Kayaku Co., Ltd .; Novorak type such as Epicron N-680 manufactured by DIC Co., Ltd. and EOCN-104S manufactured by Nippon Kayaku Co., Ltd. Epoxy resin, biphenyl type epoxy resin such as YX-4000 manufactured by Mitsubishi Chemical Co., Ltd., phosphorus-containing epoxy resin such as TX0712 manufactured by Nippon Steel & Sumitomo Metal Corporation, tris (2,3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan Chemical Co., Ltd., etc. Can be mentioned. By containing the solid epoxy resin, the glass transition temperature of the cured product becomes high and the heat resistance is excellent. Among solid epoxy resins, a cured product having a higher Tg and a lower dielectric loss tangent can be obtained. Therefore, an aralkyl type epoxy resin such as ESN-475V or NC3000H, that is, a divalent epoxy resin in which an alkylene group and an arylene group are bonded. An epoxy resin containing a group of is preferable. Here, examples of the alkylene group include a methylene group, a methylmethylene group, an ethylene group, a propylene group, a trimethylene group and the like. Examples of the arylene group include a phenylene group, a biphenylene group, a naphthylene group and the like.

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

As the epoxy resin (A2), one type may be used alone, or two or more types may be used in combination. The blending amount of the epoxy resin (A2) is more preferably 0.1 to 50% by mass and 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 a thermosetting resin other than the (A) epoxy resin as long as the effects of the present invention are not impaired. For example, an isocyanate compound, a blocked isocyanate compound, an amino resin, etc. Known and commonly used thermosetting resins such as benzoxazine resin, carbodiimide resin, cyclocarbonate compound, polyfunctional oxetane compound, episulfide resin, and maleimide resin can be used.

[(B) Compound having 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 of a carboxylic acid compound and a hydroxy compound. Of these, a compound having an active ester group obtained by using a phenol compound or a naphthol compound as the hydroxy compound is preferable. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, 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, trihydroxybenzophenol, tetrahydroxybenzophenone, fluoroglusin, benzenetriol , Dicyclopentadienyldiphenol, phenol novolac and the like. Further, as the compound (B) having an active ester group, a naphthalenediol alkyl / benzoic acid type may be used. (B) As the compound having an active ester group, one type may be used alone, or two or more types may be used in combination. (B) As the compound having an active ester group, a compound having any one of benzene, α-naphthol, β-naphthol and a dicyclopentadiene skeleton is preferable.

(B) When the non-volatile component in the resin composition is 100% by mass, the upper limit of the compounding amount of the compound having an active ester group is preferably 50% by mass or less from the viewpoint of the strength of the cured product. It is more preferably mass% or less, and particularly preferably 40 mass% or less. Further, since a cured product having a lower dielectric loss tangent can be obtained, the lower limit is preferably 5% by mass or more, and more preferably 10% by mass or more.

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

(B1)
The compound having the active ester group of (B1) includes (b1) a phenol 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. The phenolic hydroxyl group in the (b1) phenolic resin is 0.05 to 0.75 mol with respect to 1 mol of the carboxyl group or the acid halide group in the (b2) aromatic dicarboxylic acid or its halide, and the above (b3). Those having a structure obtained by reacting an aromatic monohydroxy compound at a ratio of 0.25 to 0.95 mol are preferable.

Here, in (b1) phenol resin, the molecular structure in which phenols are knotted via an aliphatic cyclic hydrocarbon group is an unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule. Examples thereof include a structure obtained by a double addition reaction with phenols. Here, examples of the phenols include phenols and substituted phenols in which one or more alkyl groups, alkenyl groups, allyl groups, aryl groups, aralkyl groups, halogen groups and the like are substituted. Specific examples thereof include cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorphenol, bromphenol, naphthol, and dihydroxynaphthalene. However, it is not limited to these. Moreover, you may use a mixture of these. Among these, phenol is particularly preferable because it has excellent fluidity and curability.

Specific examples of the unsaturated alicyclic hydrocarbon compound include dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, 5-vinylnorbona-2-ene, α-pinene, β-pinene, and limonene. Can be mentioned. Among these, dicyclopentadiene is preferable from the viewpoint of characteristic balance, particularly heat resistance and hygroscopicity. In addition, since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain other aliphatic or aromatic diene as impurities, but it has heat resistance and curability. Considering moldability and the like, it is desirable that the product has a purity of 90% by mass or more of dicyclopentadiene.

Next, the (b2) aromatic dicarboxylic acid or halide thereof is an aromatic dicarboxylic acid such as isophthalic acid, terephthalic acid, 1,4-, 2,3-, or 2,6-naphthalenedicarboxylic acid, and these. Examples thereof include acid halides such as acid fluorides, acid acid compounds, acid bromides and acid iodides. Among these, an acid chloride of an aromatic dicarboxylic acid is preferable from the viewpoint of particularly good reactivity, and dichloride of isophthalic acid and dichloride of terephthalic acid are preferable, and dichloride of isophthalic acid is particularly preferable.

Next, as the aromatic monohydroxy compound, for example, phenol; alkylphenols such as o-cresol, m-cresol, p-cresol, 3,5-xylenol; o-phenylphenol, p-phenylphenol, 2-benzyl Aralkylphenols such as phenol, 4-benzylphenol and 4- (α-cumyl) phenol; naphthols such as α-naphthol and β-naphthol can be mentioned. Among these, α-naphthol and β-naphthol are particularly preferable because the dielectric loss tangent of the cured product is lowered.

（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。 The (B1) 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, and in particular. , The following general formula (1)

(In the formula, 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, or a benzene ring or a naphthalene ring may be bonded to the molecular terminal via another atom, and is substituted. It may have a group. Further, the (B1) active ester compound preferably has a naphthalene ring at the molecular terminal thereof.

In particular, in the above general formula (1), the value of n, that is, the average value of the repeating units in the range of 0.25 to 1.5 has a low solution viscosity and is easy to produce into a dry film for build-up. It is preferable from the point of view. Further, in the general formula (1), the value of k is preferably 0 from the viewpoint of high heat resistance and low dielectric loss tangent.

Here, n in the above general formula (1) can be obtained as follows.
[How to find n in general formula (1)]
Styrene-equivalent molecular weights (α1, α2, α3, α4) corresponding to each of n = 1, n = 2, n = 3, and n = 4 and n = 1, n = by GPC measurement performed under the following conditions. The ratios (β1 / α1, β2 / α2, β3 / α3, β4 / α4) to the theoretical molecular weights (β1, β2, β3, β4) of 2, n = 3, and n = 4 were obtained, and these (β1 / Obtain the average value of α1 to β4 / α4). The value obtained by multiplying the number average molecular weight (Mn) obtained by GPC by this average value is defined as the average molecular weight. Next, the value of n is calculated by 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: Tosoh guard column "H _XL- L"
+ "TSK-GEL G2000HXL" manufactured by Tosoh
+ "TSK-GEL G2000HXL" manufactured by Tosoh
+ "TSK-GEL G3000HXL" manufactured by Tosoh
+ "TSK-GEL G4000HXL" manufactured by Tosoh
Detector: RI (differential refractometer)
Data processing: Tosoh "GPC-8020 Model II Version 4.10"
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran flow rate 1.0 ml / min Standard: The following monodisperse polystyrene with a known molecular weight was used in accordance with the measurement manual of the above-mentioned "GPC-8020 Model II Version 4.10".
(Polystyrene used)
"A-500" manufactured by Tosoh
"A-1000" manufactured by Tosoh
"A-2500" manufactured by Tosoh
"A-5000" manufactured by Tosoh
Tosoh "F-1"
Tosoh "F-2"
Tosoh "F-4"
"F-10" manufactured by Tosoh
Tosoh "F-20"
Tosoh "F-40"
Tosoh "F-80"
"F-128" manufactured by Tosoh
Sample: A solution obtained by filtering 1.0% by mass of a tetrahydrofuran solution in terms of resin solid content with a microfilter (50 μl).

The method of reacting (b1) a phenol resin, (b2) an aromatic dicarboxylic acid or a halide thereof, and (b3) an aromatic monohydroxy compound specifically reacts each of these components in the presence of an alkaline catalyst. Can be made to.
Examples of the alkaline catalyst that can be used here include sodium hydroxide, potassium hydroxide, triethylamine, pyridine and the like. Among these, sodium hydroxide and potassium hydroxide are particularly preferable because they can be used in an aqueous solution state and the productivity is improved.

Specifically, in the reaction, (b1) a phenol resin, (b2) an aromatic dicarboxylic acid or a halide thereof, and (b3) an aromatic monohydroxy compound are mixed in the presence of an organic solvent, and the alkaline catalyst or the same thereof. Examples thereof include a method in which the aqueous solution is continuously or intermittently dropped and reacted. At that time, the concentration of the aqueous solution of the alkaline catalyst is preferably in the range of 3.0 to 30%. In addition, examples of the organic solvent that can be used here include toluene and dichloromethane.

After completion of the reaction, if an aqueous solution of an alkaline catalyst is used, the reaction solution is statically separated, the aqueous layer is removed, and the remaining organic layer is repeated until the washed aqueous layer becomes almost neutral. The target resin can be obtained.

The compound having the active ester group (B1) thus obtained is usually obtained as an organic solvent solution, and therefore, when used as a varnish for a laminated board or a dry film for build-up, other compounding components are used as they are. The desired curable resin composition can be produced by mixing with the above and further adjusting the amount of the organic solvent as appropriate. The active ester compound (B1) is characterized by having a low melt viscosity when dissolved in an organic solvent to prepare a resin solution. Specifically, it is used as an active ester resin in a toluene solution having a non-volatile content of 65%. 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 the active ester group of (B2) has the following general formula (2):

It has a structural portion represented by and has a resin structure in which both ends thereof 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 equation (2), X ₂ is independently the following equation (3):

Group represented by or the following formula (4):

In the group represented by, m is an integer of 1 to 6, n is an integer of 1 to 5 independently, and q is an integer of 0 to 6 independently, respectively, and the equation (3) In the formula (4), Y is a group represented by the above formula (3) (k is an integer of 1 to 5 independently). t is an integer from 0 to 5 independently)

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 the active ester group of (B2) is described in the general formula (2).

The partial structure represented by has a hydroxyl group equivalent of 170 to 200 g / eq. It is preferable that the structure is derived from the modified naphthalene compound of.

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

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

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

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

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 having the active ester group of (B2) has a naphthylene ether structural portion in the molecular main skeleton, more excellent heat resistance and flame retardancy can be imparted to the cured product, and the structural portion has the following structure. Site

Since it has a structure bonded by, the cured product can have more excellent dielectric properties. Further, in the resin structure of the compound having the active ester group of (B2), by adopting an aryloxy group as the structure at both ends, the heat-resistant decomposition property of the cured product is sufficiently advanced even in the use of a multilayer printed circuit board. Is obtained.

The compound having the active ester group of (B2) is preferably a compound having a softening point in the range of 100 to 200 ° C., particularly preferably in the range of 100 to 190 ° C., from the viewpoint of excellent heat resistance of the cured product.

Among the compounds having an active ester group of (B2), m in the formula (2) is an integer of 1 to 6. Of these, those in which m is an integer of 1 to 5 are preferable. Further, n in the equation (2) may be an integer of 1 to 5 independently. Of these, those in which n is an integer of 1 to 3 are preferable.
In the formula (2), the relationship between m and n is described just in case. For example, when m is an integer of 2 or more, n of 2 or more occurs, but in that case, n is an independent value. is there. As long as it is within the numerical range of n, it may be the same value or it may be a different value.

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

Examples of the aryloxy groups at both ends of the resin structure are those derived from monohydric phenolic compounds such as phenol, cresol, pt-butylphenol (paratershary butylphenol), 1-naphthol, and 2-naphthol. Among them, a phenoxy group, a triloxy group or a 1-naphthyloxy group is preferable, and a 1-naphthyloxy group is more preferable, from the viewpoint of thermostable decomposition of the cured product.

Hereinafter, the method for producing the compound having the active ester group of (B2) will be described in detail.
The method for producing the compound having the active ester group of (B2) is a step of reacting a dihydroxynaphthalene compound and a 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"). (May be abbreviated as), then a step of reacting the obtained benzyl-modified naphthalene compound with an aromatic dicarboxylate compound and a monovalent phenolic compound (hereinafter, this step may be abbreviated as "step 2"). There is) and.

That is, first, in step 1, the dihydroxynaphthalene compound and benzyl alcohol are reacted in the presence of an acid catalyst to have a naphthylene structure as a main skeleton and 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 bonded in a pendant shape on an aromatic nucleus can be obtained. Here, it should be noted that, in general, when a dihydroxynaphthalene compound is naphthylene etherified under an acid catalyst, it is extremely difficult to adjust the molecular weight and the molecular weight becomes high, whereas the above production method is benzyl alcohol. By using the above in combination, such a high molecular weight increase can be suppressed, and a resin suitable for use in electronic materials can be obtained.

Further, by adjusting the amount of benzyl alcohol used, in addition to being able to adjust the content of benzyl groups in the target benzyl-modified naphthalene compound, the melt viscosity itself of the benzyl-modified naphthalene compound can also be adjusted. Become. That is, usually, the reaction ratio of the dihydroxynaphthalene compound to benzyl alcohol is 1 / 0.1 to 1 for the reaction ratio of the dihydroxynaphthalene compound to benzyl alcohol (dihydroxynaphthalene compound) / (benzyl alcohol) on a molar basis. It can be selected from the range of 1/10, but the reaction ratio of the dihydroxynaphthalene compound to benzyl alcohol (dihydroxynaphthalene compound) on a molar basis from the balance of heat resistance, flame retardancy, dielectric property, and heat decomposition property. / (Benzyl alcohol) is preferably in the range of 1 / 0.5 to 1 / 4.0.

The dihydroxynaphthalene compounds that can be used here are, for example, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7. Examples thereof include −dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene. Among these, 1,6-dihydroxynaphthalene is obtained because the cured product of the obtained benzyl-modified naphthalene compound has better flame retardancy, and the dielectric loss tangent of the cured product is lowered and the dielectric properties are improved. Alternatively, 2,7-dihydroxynaphthalene is preferable, and 2,7-dihydroxynaphthalene is more preferable.

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

The amount of the acid catalyst used can be appropriately selected depending on the target modification rate and the like. For example, in the case of an inorganic acid or an organic acid, 0.001 to 5 per 100 parts by mass of the dihydroxynaphthalene compound. It is in the range of 0 parts by mass, preferably 0.01 to 3.0 parts by mass, and in the case of Friedel-Crafts catalyst, 0.2 to 3.0 mol, preferably 0.5 to 3.0 mol, per 1 mol of the dihydroxynaphthalene compound. The range is preferably 2.0 mol.

The reaction between the dihydroxynaphthalene compound and benzyl alcohol in the step 1 can be carried out without a solvent, or can be carried out under a solvent from the viewpoint of enhancing the uniformity in the reaction system. Examples of such a solvent 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. Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether and other ethylene glycol and diethylene glycol mono or diether; non-polar aromatic solvents such as benzene, toluene and xylene; non-polar aromatic solvents such as dimethylformamide and dimethylsulfoxide. Protonic polar solvent; chlorobenzene and the like.

The specific method for carrying out the reaction in step 1 is to dissolve the dihydroxynaphthalene compound, benzyl alcohol and the acid catalyst in the absence of a solvent or in the presence of the solvent, and the temperature is about 60 to 180 ° C., preferably about 80 to 160 ° C. It can be done under temperature conditions. The reaction time is not particularly limited, but is preferably 1 to 10 hours. Therefore, the reaction can be carried out specifically by holding the 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 fractional distillation tube or the like because the reaction proceeds rapidly and the productivity is improved.

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

After completion of the reaction, the acid catalyst can be removed by neutralization treatment, washing treatment or decomposition, and a resin having a desired phenolic hydroxyl group can be separated by general operations such as extraction and distillation. The neutralization treatment and the washing treatment may be carried out according to a conventional method. For example, basic substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, triethylenetetramine and aniline can be used as the neutralizing agent.

Here, as the aromatic dicarboxylic acid compound, specifically, phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid. Examples include the acidified product of. Of these, 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 monovalent phenolic compound include phenol, cresol, pt-butylphenol, 1-naphthol, 2-naphthol and the like. Of these, phenol, cresol, and 1-naphthol are preferable from the viewpoint of good reactivity with carboxylic acid chloride, and 1-naphthol is more preferable from the viewpoint of good thermal decomposition resistance.

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

Examples of the alkaline catalyst that can be used here include sodium hydroxide, potassium hydroxide, triethylamine, pyridine and the like. Among these, sodium hydroxide and potassium hydroxide are particularly preferable because they can be used in an aqueous solution state and the productivity is improved.

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

After completion of the reaction, if an aqueous solution of an alkaline catalyst is used, the reaction solution is statically separated, the aqueous layer is removed, and the remaining organic layer is repeated until the washed aqueous layer becomes almost neutral. The target resin can be obtained.

The compound having the active ester group (B2) thus obtained is preferable when the softening point is 100 to 200 ° C. because the solubility in an organic solvent is high.

(Hardener)
The curable resin composition of the present invention may contain a curing agent other than the compound (B) having an active ester group as long as the effects of the present invention are not impaired. For example, a compound having a phenolic hydroxyl group, poly Examples thereof include carboxylic acids and their acid anhydrides, compounds having a cyanate ester group, compounds having a maleimide group, and alicyclic olefin polymers. From the viewpoint of adhesion, a compound having a phenolic hydroxyl group is preferable.

Examples of the compound having a phenolic hydroxyl group include phenol novolac resin, alkylphenol volac resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene-modified phenol resin, cresol / naphthol resin, and polyvinylphenols. Conventionally known ones such as phenol / naphthol resin, α-naphthol skeleton-containing phenol resin, triazine skeleton-containing cresol novolac resin, biphenyl aralkyl type phenol resin, and zylock type phenol novolac resin can be used.
Among the compounds having a phenolic hydroxyl group, the hydroxyl group equivalent is 100 g / eq. The above is preferable. The hydroxyl group equivalent is 100 g / eq. Examples of the compounds having the above phenolic hydroxyl groups include dicyclopentadiene skeleton phenol novolac resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), zylock 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), cresol novolak resin containing triazine skeleton (LA-3018-50P, manufactured by DIC), phenol containing triazine skeleton Examples thereof include novolak resin (LA-7052, manufactured by DIC).

The compound having a cyanate ester group is preferably a compound having two or more cyanate ester groups (-OCN) in one molecule. As the compound having a cyanate ester group, any conventionally known compound can be used. Examples of the compound having a cyanate ester group include phenol novolac type cyanate ester resin, alkylphenol novolac type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, and bisphenol S type. Cyanate ester resin can be mentioned. Further, it may be a prepolymer in which a part is triazine-ized.

Commercially available compounds having a cyanate ester group include phenol novolac type polyfunctional cyanate ester resin (manufactured by Lonza Japan, PT30S), and a prepolymer in which some or all of bisphenol A disicianate is triazined to form a trimer. (Lonza Japan Co., Ltd., BA230S75), dicyclopentadiene structure-containing cyanate ester resin (Lonza Japan Co., Ltd., DT-4000, DT-7000) and the like can be mentioned.

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, and N, N'-1,3-phenylenedi maleimide, N, N'-1,4-phenylenedi maleimide, N, N'-4. , 4-Diphenylmethanebismaleimide, 1,2-bis (maleimide) ethane, 1,6-bismaleimide hexane, 1,6-bismaleimide- (2,2,4-trimethyl) hexane, 2,2'-bis- [4- (4-Maleimidephenoxy) phenyl] Propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, bis ( 3-Ethyl-5-methyl-4-maleimidephenyl) methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane maleimide, and oligomers thereof, and at least one of diamine condensates having a maleimide skeleton. Is more preferable. The oligomer is an oligomer obtained by condensing a compound having a maleimide group, which is a monomer among the above-mentioned compounds having a maleimide group.

Commercially available compounds having a maleimide group include BMI-1000 (4,5'-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'-diphenylmethane bismaleimide, 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 so on.

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

(Inorganic filler)
The curable resin composition of the present invention preferably contains an inorganic filler. By blending an inorganic filler, the curing shrinkage of the obtained cured product is suppressed, the CTE becomes lower, and the adhesion, hardness, crack resistance, etc. by matching the thermal strength with the conductor layer such as copper around the insulating layer, etc. The thermal characteristics of can be improved. Conventionally known inorganic fillers can be used as the inorganic fillers and are not limited to specific ones. For example, barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica and the like, talc and clay. , Neuburg silica soil 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, platinum and other metal powders. The inorganic filler is preferably spherical particles. Among them, silica is preferable, and it suppresses the curing shrinkage of the cured product of the curable composition, lowers the CTE, and improves the properties such as adhesion and hardness. The average particle size (median diameter, 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 processability. In the present specification, the average particle size of the inorganic filler is the 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 determined by a laser diffraction type particle size distribution measuring device. Examples of the measuring device by the laser diffraction method include Nanotrac wave manufactured by Nikkiso Co., Ltd.

The inorganic filler is preferably a surface-treated inorganic filler. As the surface treatment, a surface treatment using a coupling agent or a surface treatment such as an alumina treatment that does not introduce an organic group 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. A surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group, is used as an inorganic filler. The surface may be treated.

The surface treatment of the inorganic filler is preferably a surface treatment with a coupling agent. As the coupling agent, a silane-based, titanate-based, aluminate-based, zircoaluminate-based coupling agent or the like can be used. Of these, a silane coupling agent is preferable. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, and 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, etc. can be mentioned, which may be used alone or in combination. Can be used. These silane-based coupling agents are preferably immobilized on the surface of the inorganic filler in advance by adsorption or reaction. Here, the treated 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.

As the curable reactive group, a thermosetting reactive group is preferable. Examples of the thermosetting reactive group include a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group and an oxazoline group. Can be mentioned. Of these, 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.

The surface-treated inorganic filler may be contained in the curable resin composition in the surface-treated state, and the curable resin composition is composed by separately blending the inorganic filler and the surface treatment agent. The inorganic filler may be surface-treated in the product, but it is preferable to blend the inorganic filler which has been surface-treated in advance. By blending the inorganic filler that has been surface-treated in advance, it is possible to prevent a decrease in crack resistance and the like due to the surface-treating agent that may remain after being blended separately and is not consumed in the surface treatment. In the case of surface treatment in advance, it is preferable to mix a pre-dispersion solution in which an inorganic filler is pre-dispersed in a solvent or a curable resin. It is more preferable that the surface-untreated inorganic filler is sufficiently surface-treated when it is pre-dispersed in a solvent, and then the pre-dispersion solution is blended into the composition.

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

The inorganic filler may be used alone or as a mixture of two or more. When the non-volatile component in the resin composition is 100% by mass, the blending 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 reducing CTE. preferable. Further, from the viewpoint of toughness of the cured film, 90% by mass or less is preferable, and 85% by mass or less is more preferable.

(Curing accelerator)
The curable resin composition of the present invention can contain a curing accelerator. The curing accelerator promotes a thermosetting reaction, and is used to further improve properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such a curing accelerator include imidazole and its derivatives; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulphon, dicyandiamide, urea, urea derivatives, Polyamines such as melamine, polybasic hydrazide; these organolates and / or epoxy adducts; 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-methylmorpholin, hexa (N-) Amines such as methyl) melamine, 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine , Organic phosphines such as triphenylphosphine, tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosphonium chloride; benzyltrimethylammonium chloride, phenyltributyl Tertiary ammonium salts such as ammonium chloride; said polybasic acid anhydride; photocationic polymerization of diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate and the like. Catalyst; styrene-maleic anhydride resin; equimolar reactants of phenylisocyanate and dimethylamine, equimolar reactants of organic polyisocyanate and dimethylamine such as tolylene diisocyanate and isophorone diisocyanate, and conventionally known curing acceleration of metal catalysts Agents can be mentioned. Among the curing accelerators, imidazole and its derivative, dimethylaminopyridine are preferable, and imidazole and its derivative are more preferable because a cured product having a higher Tg and a low dielectric loss tangent can be obtained.

The curing accelerator may be used alone or in combination of two or more. When the non-volatile component in the resin composition is 100% by mass, the amount of the curing accelerator is preferably 5% by mass or less, preferably 3% by mass or less, from the viewpoint of storage stability of the resin composition before the thermosetting reaction. 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 obtained cured film. The thermoplastic resin is preferably soluble in a solvent. When it is soluble in a solvent, the flexibility is improved when it is formed into a dry film, and the generation of cracks and powder falling can be suppressed. As the thermoplastic resin, various acid anhydrides or acid chlorides are used for the thermoplastic polyhydroxypolyether resin, the phenoxy resin which is a condensate of epichlorohydrin and various bifunctional phenol compounds, or the hydroxyl group of the hydroxyether portion existing in the skeleton thereof. Examples thereof include a phenoxy resin, a polyvinyl acetal resin, a polyamide resin, a polyamide-imide resin, and a block copolymer that have been esterified. The thermoplastic resin may be used alone or in combination of two or more. Among these thermoplastic resins, a phenoxy resin is preferable because the glass transition temperature can be improved while maintaining a low dielectric loss tangent. A polyvinyl acetal resin is preferable from the viewpoint of reducing the roughness of the surface of the cured product 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 for example, formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, 3-. Examples thereof include methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde, and butylaldehyde is preferable.

Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YX6954, YL6954, YL6974, and YX7200 manufactured by Mitsubishi Chemical Corporation. Specific examples of the polyvinyl acetal resin include the Eslek KS series manufactured by Sekisui Chemical Co., Ltd., the polyamide resin includes the KS5000 series manufactured by Hitachi Kasei Kogyo Co., Ltd., the BP series manufactured by Nippon Kayaku Co., Ltd., and the polyamide-imide resin. KS9000 series manufactured by Hitachi Kasei Kogyo Co., Ltd. and the like can be mentioned. The blending amount of the thermoplastic resin is from the viewpoint of the mechanical strength of the obtained cured film when the total of the epoxy resin (A) and the compound having the active ester group (B) in the resin composition is 100% by mass. , 0.1% by mass or more is preferable, and 0.3% by mass or more is more preferable. Further, from the viewpoint of the dielectric property of the cured film, 30% by mass or less is preferable, and 20% by mass or less is more preferable.

(Rubber-like particles)
The curable resin composition of the present invention may contain rubber-like particles, if necessary. Examples of such rubber-like 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-modified or hydroxyl-modified acrylonitrile butadiene rubber, and Examples thereof include crosslinked rubber particles and core-shell type rubber particles, and one type can be used alone or in combination of two or more types. These rubber-like particles are added to improve the flexibility of the obtained cured film, improve crack resistance, enable surface roughness treatment with an oxidizing agent, and improve the adhesion strength with copper foil and the like. Will be done.

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

(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 nitrate, molybdenum compound, bromine compound, chlorine compound, and phosphoric acid ester. , Phosphoric acid-containing polyol, phosphorus-containing amine, melamine cyanurate, melamine compound, triazine compound, guanidine compound, silicon polymer and the like can be used. The flame retardant may be used alone or in combination of two or more.

(Organic solvent)
The organic solvent is not particularly limited, and examples thereof include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. it can. More specifically, ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol and 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, propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. In addition to system solvents and the like, N, N-dimethylformamide (DMF), tetrachloroethylene, televisionne oil and the like can be mentioned. In addition, Maruzen Petrochemical Co., Ltd. Swazol 1000, Swazol 1500, Standard Oil Osaka Sales Office Co., Ltd. Solbesso 100, Solvesso 150, Sankyo Chemical Co., Ltd. Solvent # 100, Solvent # 150, Shell Chemicals Japan Co., Ltd. Shell Zol A100, Shell Zol A150 , Idemitsu Kosan Co., Ltd. Ipsol No. 100, Ipsol No. 150 and other organic solvents may be used. The organic solvent may be used alone or in combination of two or more.

When formed into a dry film, the amount of residual solvent in the resin layer is preferably 0.5 to 10.0% by mass. When the residual solvent 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 the melt viscosity being lowered too much, and the flatness is improved. When the residual solvent is 0.5% by mass or more, the fluidity at the time of laminating is good, and the flatness and embedding property are more good.

(Other ingredients)
The curable resin composition of the present invention further comprises organic fillers such as silicon powder, fluorine powder, nylon powder, phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, as required. Conventionally known colorants such as carbon black and naphthalene black, conventionally known thickeners such as asbestos, olben, benton, and fine powder silica, silicone-based, fluorine-based, and polymer-based defoamers and / or leveling agents. , Thiazol-based, Triazole-based, Adhesion-imparting agents such as silane coupling agents, and 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-component or two-component or more, but it is preferably two-component or more from the viewpoint of storage stability.

[Dry film]
The dry film of the present invention can be produced by applying the curable resin composition of the present invention on a carrier film and drying it 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 the resin layer is formed. Examples of the carrier film include polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polyethylene films, polytetrafluoroethylene films, polypropylene films, and films made of thermoplastic resins such as polystyrene films. 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 according to the application. The surface of the carrier film on which the resin layer is provided may be subjected to a mold release treatment. Further, sputtered or ultrathin copper foil may be formed on the surface of the carrier film on which the resin layer is provided.

The protective film is provided on the surface of the resin layer opposite to the carrier film for the purpose of preventing dust and the like 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 the thermoplastic resin exemplified in the carrier film, surface-treated paper and the like can be used, and 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 according to the application. The surface of the protective film on which the resin layer is provided may be subjected to a mold release treatment.

[Copper foil with resin]
The resin-containing copper foil of the present invention has a resin layer obtained by applying the curable resin composition of the present invention to a copper foil or an ultrathin copper foil with a carrier and drying it.

The copper foil may be an electrolytic copper foil or a rolled copper foil. The thickness is usually 250 μm or less, preferably 9 to 200 μm. The surface to be coated with the curable resin composition is preferably roughened with copper chloride or the like because the adhesion between the copper foil and the resin layer can be improved.

The method for forming the ultrathin copper foil is not particularly limited, and it is 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 ultrathin copper foil is preferably 0.1 to 7.0 μm, more preferably 0.5 to 5.0 μm, and even more preferably 1.0 to 3.0 μm.

The ultrathin copper foil with a carrier may have a structure in which the carrier foil and the ultrathin 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 ultrathin copper foil. You just have to.

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

The method for forming the ultrathin copper foil is not particularly limited, and the ultrathin copper foil is 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 ultrathin copper foil is preferably 0.1 to 7.0 μm, more preferably 0.5 to 5.0 μm, and even more preferably 1.0 to 3.0 μm.

[Prepreg]
The prepreg of the present invention is obtained by applying and / or impregnating a sheet-like fibrous base material with the curable resin composition of the present invention and drying. Examples of the sheet-like fibrous base material include glass cloth, glass, and aramid non-woven 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 it may be cured by a conventionally known method, for example, it may be cured 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 is performed. 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 on the circuit board on which the circuit pattern is formed, and then thermosetting. The thermosetting may be cured in an oven or may be cured by a hot plate press. When laminating or hot plate pressing the substrate on which the circuit is formed and the dry film of the present invention, the copper foil or the substrate on which the circuit is formed can be laminated at the same time. A printed wiring board can be manufactured by forming a pattern or via hole by laser irradiation or a drill at a position corresponding to a predetermined position on a substrate on which a circuit pattern is formed to expose 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, the desmear treatment is performed. The remaining carrier film or protective film may be peeled off either after laminating, after thermosetting, after laser processing, or after desmear treatment. The interlayer circuit may be connected by a copper pillar.

Further, when a printed wiring board is manufactured using the copper foil with resin of the present invention, a resin layer is laminated on a circuit board on which a circuit pattern is formed, and a subtractive process or an ultrathin copper foil is applied to the entire wiring layer or. As a part, the circuit may be formed by the modified semi-additive process (MSAP) method to manufacture a build-up wiring board. Further, a build-up wiring board in which a circuit is formed by a semi-additive process (SAP) method may be manufactured by removing the ultrathin copper foil. Further, the printed wiring board may be manufactured by a direct build-up on wafer in which the lamination of the copper foil with resin and the circuit formation are alternately repeated on the semiconductor integrated circuit. Further, 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 components, particularly a printed wiring board, and particularly preferably for forming a coverlay for a solder resist layer, an interlayer insulating layer, and a flexible printed wiring board. Can be used. Further, it can be suitably used for filling permanent holes in a printed wiring board, for example, filling holes 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 in which transmission loss is an issue. Specific examples of high-frequency applications include millimeter-wave radars and millimeter-wave sensor substrates for automatic operation, mobile motherboards that support high-speed communication, and SLPs (Substation-Like PCBs) that form circuits using the Modified Semi-Additive Process (MSAP) method. ), Application processors (AP) for mobile and personal computers, HDI (high density interconnect) boards and PKG (package) boards for smartphones, tablets and personal computers, high-multilayer boards for base station servers and routers, boards for antennas and semiconductors. Examples include a sealing material. A wiring board may be formed by bonding wirings using the dry film of the present invention. The electronic component may be an application other than the printed wiring board, for example, a passive component such as an inductor.

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

The dielectric loss tangent of the cured product of the present invention is not particularly limited, but according to the present invention, it is possible to obtain a cured product having a low dielectric loss tangent, for example, 0.005 or less, further 0.003 or less, and further. It can be 0.002 or less.

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, "part" and "%" are all based on mass unless otherwise specified.

<Synthesis of compounds with active ester groups>
(Synthesis Example 1: Synthesis of a compound having an active ester group of (B-1))
203.0 g of isophthalic acid chloride (number of moles of acid chloride group: 2.0 mol) and 1338 g of toluene were charged in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractional tube, and a stirrer, and the inside of the system was replaced with reduced pressure nitrogen. And dissolved. Next, 96.0 g (0.67 mol) of α-naphthol and 220 g of dicyclopentadienephenol resin (number of moles of phenolic hydroxyl group: 1.33 mol) were charged, and the inside of the system was replaced with nitrogen under reduced pressure to dissolve it. Then, 1.12 g of tetrabutylammonium bromide was dissolved, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours while controlling the inside of the system to 60 ° C. or lower while performing nitrogen gas purging.
Then, stirring was continued for 1.0 hour under this condition. After completion of the reaction, the liquid was separated by standing and the aqueous layer was removed. Further, water was added to the toluene phase in which the reaction product was dissolved, and the mixture was stirred and mixed for about 15 minutes, and then allowed to stand and separated to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Then, water was removed by decanter dehydration to obtain an active ester resin (B-1) in a toluene solution with a non-volatile content of 65%. The solid content-equivalent ester group equivalent of the obtained active ester resin (B-1) was 223 g / eq. Met.

(Synthesis Example 2: Synthesis of Compound Having Active Ester Group of (B-2))
320 g (2.0 mol) of 2,7-dihydroxynaphthalene, 184 g (1.7 mol) of benzyl alcohol, paratoluenesulfonic acid in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractional tube, and a stirrer. 5.0 g of monohydrate was charged, and the mixture was stirred at room temperature while blowing nitrogen. Then, the temperature was raised to 150 ° C., and the generated water was stirred for 4 hours while being distilled off from the system. After completion of the reaction, 900 g of methyl isobutyl ketone and 5.4 g of a 20% aqueous sodium hydroxide solution were added to neutralize the mixture, and then the aqueous layer was removed by liquid separation, and the mixture was washed with 280 g of water three times to reduce the pressure of methyl isobutyl ketone. The bottom was removed to obtain 460 g of a benzyl-modified naphthalene compound (B-2 intermediate). The obtained benzyl-modified naphthalene compound (B-2 intermediate) was a black solid and had a hydroxyl group equivalent of 180 g / eq. Met.
203.0 g of isophthalic acid chloride (number of moles of acid chloride group: 2.0 mol) and 1400 g of toluene are charged in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractional tube, and a stirrer to reduce the pressure in the system. It was replaced with toluene and dissolved. Next, 96.0 g (0.67 mol) of α-naphthol and 240 g (molar number of phenolic hydroxyl groups: 1.33 mol) of the benzyl-modified naphthalene compound (B-2 intermediate) were charged, and the inside of the system was replaced with nitrogen under reduced pressure. It was dissolved. Then, 0.70 g of tetrabutylammonium bromide was dissolved, and while purging with nitrogen gas, the temperature inside the system was controlled to 60 ° C. or lower, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Then, stirring was continued for 1.0 hour under this condition. After completion of the reaction, the liquid was separated by standing and the aqueous layer was removed. Further, water was added to the toluene layer in which the reaction product was dissolved, and the mixture was stirred and mixed for 15 minutes, and the solution was allowed to be separated to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Then, water was removed by decanter dehydration to obtain an active ester resin (B-2) in a toluene solution state having a non-volatile content of 65% by mass. The solid content-equivalent ester group equivalent of the obtained active ester resin (B-2) was 230 g / eq. Met.

<Preparation of curable resin composition>
A curable resin composition for producing a film after curing was prepared by kneading and mixing with various components shown in Examples and Comparative Examples in Table 1 below at a ratio (part by mass) shown in Table 1. The numerical values in the table indicate parts by mass (non-volatile content conversion).

<Preparation of film after curing>
Using a film applicator, a curable resin composition was applied to the glossy surface of a copper foil (F2-WS manufactured by Furukawa Electric Co., Ltd., 18 μm thickness) for each example and comparative example, and 90 in a hot air circulation type drying oven. After drying at ° C. for 10 minutes and then curing at 200 ° C. for 60 minutes, the copper foil was peeled off to prepare a cured film (cured film) having a thickness of about 40 μm.

<Measurement of glass transition temperature (Tg) and coefficient of linear thermal expansion (CTE (α1))>
The sample obtained in the above <Preparation of film after curing> was cut out to a measurement size (size of 3 mm × 10 mm), and the glass transition temperature (Tg) was measured using TMA Q400EM manufactured by TA Instruments. .. The temperature was raised above room temperature at a temperature rise rate of 10 ° C./min, and measurements were taken twice in succession, and the glass transition temperature (Tg), which is the intersection of two tangents with different linear thermal expansion coefficients, was evaluated according to the following criteria. ..
⊚: 175 ° C or higher 〇: less than 175 ° C 170 ° C or higher ×: less than 170 ° C

<Measurement of dielectric loss tangent (Df)>
The sample obtained in the above <Preparation of film after curing> was cut out to a measurement size (size of 50 mm × 60 mm), and a dielectric loss tangent of 10 GHz at 23 ° C. was used using an SPDR dielectric resonator and a network analyzer (both manufactured by Agilent). Was measured and evaluated according to the following criteria.
⊚: less than 0.003 〇: 0.003 or more and less than 0.010 ×: 0.010 or more

<Preparation of sample for peel strength measurement>
(1) Roughening treatment of laminated board Both sides of the glass cloth base material epoxy resin double-sided copper-clad laminated board [copper foil thickness 18 μm, substrate thickness 0.3 mm, Panasonic R5715ES] on which the inner layer circuit is formed are manufactured by MEC. The copper surface was roughened (etching amount: about 1 μm) by immersing it in CZ8100 manufactured by Japan.
(2) Preparation of Copper Foil with Resin Using a film applicator, a curable resin composition was applied to each Example and Comparative Example of ultra-thin copper foil with a carrier (MT18Ex manufactured by Mitsui Kinzoku Co., Ltd., ultra-thin copper 3 μm thick). It was applied on the surface of a thin copper foil and dried in a hot air circulation type drying furnace at 90 ° C. for 10 minutes to obtain a resin-coated copper foil having a resin layer thickness of about 40 μm.
(3) Lamination of copper foil with resin Copper with resin on both sides of the laminated board subjected to roughening treatment (1) using a batch type vacuum pressurizing laminator MVLP-500 (manufactured by Meiki Co., Ltd., trade name). The coated surface of the resin composition of the foil (2) was laminated. Lamination was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then pressing at 80 ° C. and a pressure of 0.5 MPa for 30 seconds.
(4) Curing of Resin Composition A laminated plate (3) laminated with a copper foil with a resin was cured at 170 ° C. for 30 minutes in a hot air circulation type drying oven.
(5) Electrolytic Copper Plating After curing, the carrier copper foil was peeled off from both sides of the laminated plate, and the ultrathin copper foil (3 μm) on both sides was made about 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 circulation type drying oven.

<Measurement of peel strength>
Using the sample prepared by the above method, it was measured according to JIS C6481 and evaluated according to the following criteria.
⊚: 0.6 kN / m or more 〇: 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 (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, liquid, epoxy equivalent: 165 g / eq.)
* 4: Mitsubishi Chemical Corporation jER1001 (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 (active ester equivalent: 223 g / eq.)
* 7: Active ester resin B-2 synthesized in Synthesis Example 2 (active ester equivalent: 230 g / eq.)
* 8: TD-2090 manufactured by DIC (phenol novolac, hydroxyl group equivalent: 105 g / eq.)
* 9: SO-C2 manufactured by Admatex Co., Ltd. treated with phenylaminosilane (spherical silica, average particle size: 0.5 μm)
* 10: Mitsubishi Chemical Corporation jER YX6954BH30 (phenoxy resin)
* 11: 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Chemicals Corporation
* 12: Ratio of (A) total amount of epoxy groups in the epoxy resin / (B) total amount of active ester groups in the compound having active ester groups in the composition

From the results shown in the above table, it can be seen that the curable resin composition of the example can obtain a cured product 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, the (A1) epoxy equivalent is 350 to 1000 g / eq. Contains liquid or semi-solid epoxy resin
Curing characterized in that the ratio of the total amount of epoxy groups of the (A) epoxy resin to the total amount of active ester groups of the compound having the (B) active ester group in the composition is 0.2 to 0.6. Epoxy composition. The compound having the active ester group (B) has the following general formula (1).

(In the formula, X ₁ is a group having a benzene ring or a naphthalene ring, k represents 0 or 1, and n is an average of 0.25 to 1.5 in repeating units.) The curable resin composition according to claim 1, wherein the curable resin composition is present. The compound having the active ester group (B) has the following general formula (2).

(In equation (2), X ₂ is independently the following equation (3):

Group represented by or the following formula (4):

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

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