JP2021107493A - Curable resin composition, dry film, copper foil with resin, cured product, and electronic component - Google Patents

Abstract

To provide a curable resin composition that gives a cured product having high heat resistance, low dielectric constant, low dielectric loss tangent, and excellent adhesion to a conductor metal, a dry film having a resin layer obtained from the composition, a copper foil with resin, a cured product, and an electronic component.SOLUTION: A curable resin composition contains (A) an epoxy resin, (B) a compound having an active ester group, (C) an inorganic filler and (D) a polyester additive, the (D) polyester additive being a polymer having a polyalkylene glycol structure and an aliphatic polyester structure. There are also provided a dry film, a copper foil with resin, a cured product, and an electronic component each of which contains the curable resin composition.SELECTED DRAWING: None

Description

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

As an insulating material for forming electronic parts such as printed wiring boards, a curable resin composition containing an epoxy resin has been conventionally used, and in order to impart various properties to the cured product, the curability of the epoxy resin or the like has been used. Various combinations of curing agents and other components with respect to resins have been studied. For example, in Patent Document 1, an attempt is made to improve the adhesion of a cured product of a curable resin composition by using an additive in addition to two types of curing agents with respect to an epoxy resin.

Japanese Patent No. 5396805

However, the curable resin composition for forming an insulating layer of an electronic component is required to be able to form a cured product having further excellent heat resistance from the viewpoint of reliability and the like.
On the other hand, with the spread of large-capacity high-speed communication represented by the 5th generation communication system (5G) and millimeter-wave radar for ADAS (advanced driver assistance system) of automobiles, the frequency of signals of communication equipment is increasing. However, if the relative permittivity (Dk) and the dielectric loss tangent (Df) are not sufficiently low, the higher the frequency, the greater the transmission loss due to the dielectric loss, which causes problems such as signal attenuation and heat generation. It is also required to be able to form a cured product having a dielectric constant and a low dielectric loss tangent.
Further, in order to stably manufacture, operate, and maintain durability of electronic parts, it is also important to obtain a cured product of electronic parts having excellent adhesion to a conductor metal such as copper. When the adhesion of the cured product is high, the dielectric constant tends to increase.
In view of the above problems, an object of the present invention is a curable resin composition obtained from a curable resin composition capable of obtaining a cured product having high heat resistance, low dielectric constant, low dielectric loss tangent, and excellent adhesion to a conductor metal. It is an object of the present invention to provide a dry film having a resin layer, a copper foil with a resin, a cured product, and an electronic component.

An object of the present invention is
(A) Epoxy resin,
(B) A compound having an active ester group,
(C) Inorganic filler and
(D) Polyester additive,
The present inventors have found that the polyester additive (D) is achieved by a curable resin composition containing a polymer having a polyalkylene glycol structure and an aliphatic polyester structure. rice field.

In the curable resin composition of the present invention, the blending amount of the (D) polyester additive is 1% by mass or more and 35% by mass or less with respect to the total mass of the (A) epoxy resin and (B) the compound having an active ester group. Is preferable.

Further, it is preferable that the molar ratio of the polyalkylene glycol structure to the aliphatic polyester structure in the (D) polyester additive is in the range of 35 to 55: 65 to 45.

Further, the ratio of the total amount of epoxy groups of (A) epoxy resin to the total amount of active ester groups of the compound having (B) active ester groups is preferably 0.2 to 0.9.

（式中、Ｘ_１はそれぞれ独立的に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０．０５〜２．５である。）で表される化合物であることが好ましい。 The compound having the above-mentioned (B) active ester group has the following general formula (1):

(In the formula, X ₁ is a group having an independent benzene ring or naphthalene ring, respectively, k represents 0 or 1, and n is an average of 0.05 to 2.5 in repeating units.) It is preferable that it is a compound to be used.

（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構造を有する化合物であることであることが好ましい。 Further, the compound having the (B) active ester group is described in 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 compound has a structure site represented by and has a structure in which both ends thereof are monovalent aryloxy groups.

Another object of the present invention is a dry film, which comprises the above-mentioned curable resin composition as a resin layer.
A resin-containing copper foil, which comprises the above-mentioned curable resin composition as a resin layer on a copper foil or a copper foil with a carrier.
It is achieved by the above-mentioned curable resin composition, the cured product of the resin layer of the dry film, or the cured product of the resin layer of the copper foil with resin, and the electronic component characterized by having the above-mentioned cured product, respectively.

According to the curable resin composition of the present invention, the obtained cured product has high heat resistance, low dielectric constant, low dielectric loss tangent, and excellent adhesion to the conductor metal. Further, a dry film having a resin layer obtained from the curable resin composition of the present invention, a copper foil with a resin having a resin layer obtained from the curable resin composition of the present invention, a curable resin composition of the present invention, and a dry film. The cured product of the resin layer of the film or the resin layer of the copper foil with resin, and the electronic parts having this cured product also have high heat resistance, low dielectric constant, low dielectric adduct, and excellent adhesion to the conductor metal, respectively. It becomes a thing.

<Curable resin composition>
The curable resin composition of the present invention is
(A) Epoxy resin (also called component A),
(B) A compound having an active ester group (also referred to as component B),
(C) Inorganic filler (also called C component) and
(D) Polyester additive (also called D component),
The polyester additive (D) is a polymer having a polyalkylene glycol structure and an aliphatic polyester structure.

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 contains one or more kinds of (A) epoxy resins.

As the epoxy resin (A), any resin having one or more epoxy groups can be used, preferably a bifunctional epoxy resin having two epoxy groups in the molecule, and an epoxy in the molecule. Examples thereof include a polyfunctional epoxy resin having three or more groups. It may be a hydrogenated epoxy resin.

Further, it is preferable that the epoxy resin (A) contains at least one of a trifunctional or higher functional liquid epoxy resin and a trifunctional or higher semi-solid epoxy resin. When a trifunctional or higher functional liquid epoxy resin or a trifunctional or higher semi-solid epoxy resin is contained, the glass transition temperature can be improved while maintaining the dielectric loss tangent low.

The epoxy resin (A) may be any one or more of a solid epoxy resin, a semi-solid epoxy resin, and a liquid epoxy resin, but preferably contains a solid epoxy resin. Further, it is also preferable to use a liquid or semi-solid epoxy resin in terms of producing a dry film or a copper foil with a resin.

In the present specification, the solid epoxy resin refers to an epoxy resin that is solid at 40 ° C., and the semi-solid epoxy resin refers to an epoxy resin that is solid at 20 ° C. and liquid at 40 ° C., and is a liquid epoxy resin. Refers to an epoxy resin that is liquid at 20 ° 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.

Examples of the solid epoxy resin include EPICLON HP-4700 (naphthalene type epoxy resin) manufactured by DIC, NC-7000L (polyfunctional solid epoxy resin containing naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd., ESN-475V manufactured by Nittetsu Chemical & Materials Co., Ltd., etc. Naphthalene type epoxy resin; epoxidized product of a condensate of phenols such as EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd. and an aromatic aldehyde having a phenolic hydroxyl group (trisphenol type epoxy resin); Dicyclopentadiene aralkyl type epoxy resin such as EPICLON HP-7200H (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin); NC-3000H, NC-3000L (biphenyl skeleton-containing polyfunctional solid epoxy resin), etc. Biphenyl aralkyl type epoxy resin; Novorak type epoxy resin such as EPICLON N660 and EPICLON N690 manufactured by DIC, EOCN-104S manufactured by Nippon Kayaku Co., Ltd .; Biphenyl type epoxy resin such as YX-4000 manufactured by Mitsubishi Chemical Co., Ltd .; Examples thereof include phosphorus-containing epoxy resins such as TX0712 manufactured by the same company. 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 low dielectric loss tangent can be obtained. Therefore, an epoxy resin having a skeleton in which an aromatic compound and phenol or naphthol are linked by a methylene chain, such as ESN-475V and NC3000H, can be obtained. Is preferable.

Examples of the semi-solid epoxy resin include bisphenols such as EPICLON 860, EPICLON 900-IM, EPICLON EXA-4816, EPICLON EXA-4822, Nittetsu Chemical & Materials Epototo YD-134, Mitsubishi Chemical jER834, and jER872. A-type epoxy resin; naphthalene-type epoxy resin such as EPICLON HP-4032 manufactured by DIC; phenol novolac-type epoxy resin such as EPICLON N-740 manufactured by DIC; epoxy resin containing nitrogen atoms such as jER604 manufactured by Mitsubishi Chemical Co., Ltd. Be done. By containing the semi-solid epoxy resin, the glass transition temperature (Tg) of the cured product is high, the coefficient of linear thermal expansion (CTE) is low, and the crack resistance is excellent. Further, by containing the semi-solid epoxy resin, the storage stability of the dry film is excellent, and cracking and peeling can be prevented.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin, and heterocyclic epoxy resin containing a hetero atom other than nitrogen. By containing the liquid epoxy resin, the suppleness of the dry film can be improved.

As described above, the epoxy resin (A) may be used alone or in combination of two or more, but from the viewpoint of giving a low dielectric loss tangent to the cured product of the curable resin composition. Therefore, the blending amount of the epoxy resin (A) is preferably 30% by mass or less, more preferably 20% by mass or less, and more preferably 20% by mass or less, when the solid content in the resin composition is 100% by mass. It is particularly preferable that it is mass% or less. Further, from the viewpoint of the strength of the cured product, the lower limit is preferably 1% by mass or more, and more preferably 3% by mass or more.

The curable resin composition of the present invention may contain a thermosetting resin other than the 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, and a benzoxazine resin may be contained. , Carbodiimide resin, cyclocarbonate compound, polyfunctional oxetane compound, episulfide resin, maleimide resin and other known and commonly used thermosetting resins can be used.

[(B) Compound having active ester group]
The curable resin composition of the present invention contains (B) a compound having an active ester group as a curing agent for component A.
(B) The compound having an active ester group is a compound having one or more, preferably 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. Among them, 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) Among the compounds having an active ester group, the compounds having the following active ester groups (B1) and (B2) can be preferably used.

The (B1) compound having an active ester group 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 (b2) an aromatic dicarboxylic acid or a halide thereof. 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 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 the (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 unsubstituted 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 of the substituted phenol include cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorphenol, bromphenol, naphthol, and dihydroxynaphthalene. Etc., but are not limited to these. Moreover, you may use a mixture of these. Among these, unsubstituted phenol is particularly preferable from the viewpoint of 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. 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 its halide 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 salts, 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 (b3) aromatic monohydroxy compound, for example, phenol; alkylphenols such as o-cresol, m-cresol, p-cresol, 3,5-xylenol; o-phenylphenol, p-phenylphenol, Aromatic phenols such as 2-benzylphenol, 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 from the viewpoint of lowering the dielectric loss tangent of the cured product.

（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 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 obtained as follows.
[How to find n in general formula (1)]
The 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 Co., Ltd.,
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 having a known molecular weight was used in accordance with the measurement manual of "GPC-8020 Model II Version 4.10".
(Polystyrene used)
"A-500" manufactured by Tosoh
"A-1000" manufactured by Tosoh
Tosoh "A-2500"
"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"
"F-80" manufactured by Tosoh
"F-128" manufactured by Tosoh
Sample: A solution obtained by filtering 1.0 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%. Further, 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.

Since the compound having the active ester group (B1) thus obtained is usually obtained as an organic solvent solution, when it is 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, the active ester group of a toluene solution having a solid content of 65% is used. The solution viscosity of the compound to have 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構造を有するものである。 The compound having the active ester group of (B2) has the following general formula (2):

It has a structure represented by and has a 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. 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１７０〜２００グラム／当量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).

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

In the formula (2), in order to clarify the relationship between m and n, some patterns will be exemplified below, but the compound having the active ester group 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 the formula (2-I), n is an integer of 1 to 5, and when n is 2 or more, q is an integer of 0 to 6 independently.

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 when n is 2 or more, q is an integer of 0 to 6 independently.

Since the compound having the active ester group of (B2) has a naphthylene ether structural moiety in the molecular main skeleton, more excellent heat resistance and flame retardancy can be imparted to the cured product, and the structural moiety has the following formula (B2). Since it has a structure bonded at the structural portion represented by 5), the cured product can have more excellent dielectric properties. Further, in the structure of the compound having an active ester group of (B2), by adopting an aryloxy group as a structure at both ends, a sufficiently high degree of improvement in heat resistance of the cured product can be improved even in a multilayer printed circuit board application. can get.

The compound having the active ester group (B2) preferably has 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 the active ester group of (B2), those in which m in the formula (2) is an integer of 1 to 6 can be mentioned. Among them, 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. be. That is, 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 may be substituted at any position in the naphthalene ring structure.

Examples of the aryloxy groups at both ends of the 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 the step of reacting the obtained benzyl-modified naphthalene compound with the aromatic dicarboxylate compound and the 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 to have 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 compound has a high molecular weight, whereas the above-mentioned 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 the benzyl group 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 in terms of 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) is based on a molar basis from the balance between heat resistance, flame retardancy, dielectric properties, and heat decomposition resistance. / (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 catalyst that can be used in the reaction between the dihydroxynaphthalene compound and benzyl alcohol in step 1 is, for example, an inorganic acid such as phosphoric acid, sulfuric acid, or hydrochloric acid, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, or fluoromethane. Examples thereof include organic acids such as sulfonic acid, Friedelcraft 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. The range is 0 parts 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. The range is preferably 2.0 mol.

The reaction between the dihydroxynaphthalene compound and benzyl alcohol in the above 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 can be mentioned.

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 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 or salts thereof.

After completion of the reaction, the acid catalyst can be removed by neutralization treatment, washing treatment or decomposition, and the resin having the 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, specific examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, and 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 alkaline 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 alkaline 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. 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.

(B) When the solid content in the resin composition is 100% by mass, the upper limit of the 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 30 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, more preferably 10% by mass or more, and further preferably 15% by mass or more.
Conventionally, it has been thought that the heat resistance deteriorates when a large amount of a compound having an active ester group is blended as a curing agent, but surprisingly, the glass transition temperature (Tg) is high, the dielectric loss tangent and the coefficient of linear thermal expansion are low. Can be obtained as a cured product of. 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 is improved because the movement of the chain portion between the cross-linking points is controlled by increasing the volume ratio of the aromatic ester structure which is rigid and has high molecular orientation.

Further, in order to obtain a cured product having both high heat resistance and low dielectric positive contact from the curable resin composition of the present invention, a compound having (B) an active ester group, which is the total amount of epoxy groups in (A) epoxy resin. The ratio to the total amount of ester groups in the above is preferably 0.2 to 0.9, more preferably 0.2 to 0.8, still more preferably 0.2 to 0.6, and particularly preferably. Is 0.2 to 0.4.
The total amount of the epoxy groups described above can be obtained 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.
The A component and the B component may each contain a plurality of types of compounds as described later. In that case, the compounding amount is divided by the epoxy equivalent or the active ester equivalent for each compound. , The total amount of epoxy groups or the total amount of ester groups is determined.
The curable resin composition of the present invention may contain a curing agent other than the compound having the active ester group (B) as long as the effect of the present invention is 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, and alicyclic olefin polymers.

[(C) Inorganic filler]
The curable resin composition of the present invention contains (C) an inorganic filler. (C) By containing the inorganic filler, the curing shrinkage of the obtained cured product is suppressed, the CTE becomes lower, and the adhesion, hardness, and cracks due to matching the thermal strength with the conductor layer such as copper around the insulating layer. Thermal properties such as resistance can be improved. As the inorganic filler (C), conventionally known inorganic fillers can be used and are not limited to specific ones. Tarku, clay, Neuburg siliceous earth 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, Examples thereof include metal powders such as silver, palladium, aluminum, iron, cobalt, gold and platinum. The inorganic filler (C) is preferably spherical particles. Among them, silica is preferable, and the curing shrinkage of the cured product of the curable resin composition can be suppressed, the CTE can be lowered, and the properties such as adhesion and hardness can be improved. The average particle size (median diameter, D50) of the inorganic filler (C) is preferably 0.01 to 10 μm. The inorganic filler (C) is preferably silica having an average particle size of 0.01 to 3 μm. In the present specification, the average particle size of the (C) 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 Microtrack MT3000II manufactured by Microtrack Bell.

The inorganic filler (C) 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. (C) The surface treatment method of the inorganic filler is not particularly limited, and a known and commonly used method may be used, and a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group, etc. (C) The surface of the inorganic filler may be treated.

The surface treatment of the inorganic filler (C) 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 treatment amount of the coupling agent with respect to 100 parts by mass of the inorganic filler is, for example, 0.1 to 10 parts by mass, preferably 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 resin layer from the curable resin composition in the surface-treated state, and the curable resin composition forming the resin layer is surface-treated with the inorganic filler. The inorganic filler may be surface-treated in the composition by blending the agent separately, 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 liquid 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 liquid is blended into the composition.

The inorganic filler (C) may be blended 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 blended with the epoxy resin or the like.

The inorganic filler (C) may be used alone or as a mixture of two or more. When the solid content in the resin composition is 100% by mass, the amount of the inorganic filler (C) is preferably 50% by mass or more, more preferably 60% by mass or more, and 65% by mass from the viewpoint of reducing CTE. The above is more preferable. Further, from the viewpoint of toughness of the cured film, 90% by mass or less is preferable, 80% by mass or less is more preferable, and 75% by mass or less is particularly preferable.

[(D) Polyester additive]
The curable resin composition of the present invention further contains (D) a polyester additive in addition to the above components A to C. (D) The polyester additive is a polymer having a polyalkylene glycol structure and an aliphatic polyester structure. By using a polyester-based additive having such a specific structure in combination with the components A to C, a cured product having high heat resistance, low dielectric constant, low dielectric loss tangent and excellent adhesion to a conductor metal can be obtained. ..

Specific examples of the polyester additive (D) include a diblock copolymer of the formula (D-1) or a copolymer containing a triblock copolymer of the formula (D-2).
Xn-Ym (D-1)
Ym1-Xn- Ym2 (D-2)
In formula (D-1), n: m is in the range of 35-55: 65-45, preferably 40-50: 60-50.
In formula (D-2), n: m1 + m2 is in the range of 35 to 55: 65 to 45, preferably 40 to 50:60 to 50.
Further, in the formulas (D-1) and (D-2),
X is represented by polyalkylene glycol (formula HO- (RO) _p -H, R is 1 to 6 carbon atoms, preferably from 2 to 5 carbon atoms alkylene, p is, for example 2 to 1000, preferably It is a unit derived from 2 to 200).
Y is an aliphatic polyester (formula - 'represented by _{r- q CO), R' (} OR methylene, q, for example 2 to 8, preferably 5 to 7, r, for example 2 to 100, preferably It is a unit derived from 2 to 50), especially polycaprolactone ((CH ₂ ) ₅ CO ₂ ) r'(r' is, for example, 2 to 40)). Excellent adhesion can be obtained if it is derived from polycaprolactone.
The curable resin composition containing the compound of the above formula (D-1) or (D-2) as the D component has particularly improved adhesion to the conductor metal.

The compound represented by the formula (D-1) or (D-2) can be produced by a usual method for producing a block copolymer. For example, polyalkylene glycol is synthesized by condensation polymerization of alkylene oxide and water or anion ring-opening polymerization of alkylene oxide, and then caprolactone is ring-opened polymerized on its hydroxyl group by the formula (D-1) or (D-2). The compound represented can be produced.

In addition, as the (D) polyester additive, a compound containing the block copolymer represented by the above formula (D-1) or (D-2), or both of them as a part of the molecule can also be used.

The polyester additive (D) has a mass average molecular weight of Mw (measured by GPC or styrene standard) of 5,000 to 15,000, preferably 7,000 to 12, regardless of its specific structure. 000, more preferably 8,000-1,000 compounds are used.

Further, the polyester additive (D) usually has a hydroxyl value of 8 to 17 mgKOH / g, preferably 10 to 15 KOH / g, and is solid at room temperature (25 ° C.), for example, having a melting point of 40 ° C. to 70 ° C. and 75 ° C. When the viscosity is usually 3,000 to 10,000 mPa · s, preferably 3,500 to 9,000 mPa · s, it greatly contributes to performance such as adhesion to the conductor metal.

According to the composition containing the A component, the B component and the C component, a cured product having a high glass transition temperature and a low dielectric loss tangent can be obtained, but even if the D component is further contained, the glass transition temperature is high and the dielectric loss tangent is high. Although it is a low cured product, the adhesion to the conductor metal is increased, and a cured product having a low dielectric constant can be obtained.
The polyester additive (D) may be used alone or as a mixture of two or more. The blending amount of the polyester additive (D) is 2% by mass or more from the viewpoint of adhesion when the total mass of the solid content of the (A) epoxy resin and the (B) compound having an active ester group is 100% by mass. Is preferable, and 2.5% by mass or more is more preferable. Further, from the viewpoint of low dielectric constant and low dielectric loss tangent of the cured film, 25% by mass or less is preferable, 20% by mass or less is more preferable, and 10% by mass or less is particularly preferable.

[Thermoplastic 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, and a polyamide imide resin which 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.

The polyvinyl acetal resin can be obtained, for example, by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde used for this is not particularly limited, and for example, formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, 3 -Methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde and the like can be mentioned, with butylaldehyde being preferred.

Specific examples of the phenoxy resin include FX280S and FX293 manufactured by Nittetsu Chemical & Materials Co., Ltd., jER (registered trademark) YX8100BH30, jER (registered trademark) YX6954BH30, YL6954, YL6974, jER (registered trademark) YX7200B35 manufactured by Mitsubishi Chemical Corporation. Can be mentioned. 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 Co., Ltd., the BP series manufactured by Nippon Kayaku Co., Ltd., and the polyamide-imide resin. , KS9000 series manufactured by Hitachi Kasei Co., Ltd. and the like.

The blending amount of the thermoplastic resin is from the viewpoint of the mechanical strength of the obtained cured film when the total of (A) epoxy resin and (B) compound having an active ester group 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, 20% by mass or less is preferable, and 15% 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 accelerates the thermosetting reaction, and is used to further improve properties such as adhesion, chemical resistance, and heat resistance.

In the present invention, the curing accelerator can be used mainly for accelerating the reaction of (A) an epoxy resin and (B) a compound having an active ester group.

Specific examples of the curing accelerator for the curing reaction with (A) epoxy resin and (B) compound having an active ester group include imidazole and derivatives thereof; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane and m-phenylene. Polyamines such as diamine, m-xylene diamine, diaminodiphenyl sulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazide; these organic acid salts and / or epoxy adducts; amine complexes of boron trifluoride; ethyldiamino- Triazine derivatives such as S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xysilyl-S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyl Amines such as dimethylamine, pyridine, dimethylaminopyridine, N-methylmorpholin, hexa (N-methyl) melamine, 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyvinylphenol , Polyphenols such as polyvinylphenol bromide, phenol novolac, alkylphenol novolac; organic phosphines such as tributylphosphine, triphenylphosphine, tris-2-cyanoethylphosphine; tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide , Phosphonium salts such as hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride, phenyltributylammonium chloride; said polybasic acid anhydride; diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2 , 4,6-Triphenylthiopyrylium hexafluorophosphate and other photocationic polymerization catalysts; styrene-maleic anhydride resin; equimolar reactants of phenylisocyanate and dimethylamine, and organic polyisocyanates such as tolylene diisocyanate and isophorone diisocyanate. Examples thereof include conventionally known curing accelerators such as an equimolar reaction product of dimethylamine and a metal catalyst. Among the curing accelerators, imidazole and its derivatives, dimethylaminopyridine, are preferable.

As the curing accelerator, one type may be used alone or two or more types may be mixed. When the curing accelerator is blended in the curable resin composition of the present invention, the blending amount thereof is the storage of the resin composition before the thermosetting reaction when the total solid content of the A and B components is 100% by mass. From the viewpoint of stability, 5% by mass or less is preferable, 3% by mass or less 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.

[Rubber-like particles]
The curable resin composition can 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 roughening 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 1 μm, more preferably in the range of 0.2 to 1 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 or the like, and a particle size distribution of the rubber-like particles is prepared on a mass basis using Nanotrac wave manufactured by Microtrac Bell, and the median diameters thereof are averaged. It can be measured by setting the particle size.

[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. 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, solvent naphtha, etc. 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. Swazole 1000, Swazole 1500, Sankyo Chemical Co., Ltd. Solvent # 100, Solvent # 150, Shell Chemicals Japan Co., Ltd. Shellsol A100, Shellsol A150, Idemitsu Kosan Co., Ltd. Ipsol No. 100, Ipsol No. 150, etc. You may use the organic solvent of. As the organic solvent, one type can be used alone or two or more types can be used in combination.

When formed into a dry film, the amount of residual solvent in the resin layer is preferably 0.1 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. Further, 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 0.1% by mass or more, particularly 0.5 or more, the fluidity at the time of laminating is good, and the flatness and embedding property are further improved.

[Other ingredients]
The curable resin composition of the present invention further comprises organic fillers such as silicone 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, orben, 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.

In addition, in this specification, a solid content means a component excluding an organic solvent.

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 viewpoints 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, sputter or 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 opposite to the carrier film of the resin layer 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 the copper foil surface of a copper foil or a copper foil with a carrier and drying it.

[Copper foil with carrier]
The copper foil with a carrier may have a structure in which the carrier foil and the copper foil are provided in this order, and the resin layer made of the curable resin composition of the present invention may be laminated so as to be in contact with the copper foil. It is preferable to use an ultrathin copper foil as the copper foil.

Examples of the carrier foil include copper foil, aluminum foil, stainless steel (SUS) foil, and a resin film having a metal-coated surface, 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 copper foil, if necessary.

The method for forming the copper foil is not particularly limited, but an ultrathin copper foil is preferable, and a wet film forming method such as a non-electrolytic copper plating method and an electrolytic copper plating method, a dry film forming method such as sputtering and chemical vapor deposition, and a dry film forming method such as sputtering and chemical vapor deposition, and , Can be formed by a combination of these. 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.

<Cured product>
The cured product of the present invention is obtained by curing the curable resin composition of the present invention, the resin layer of the dry film of the present invention, or the resin layer of the resin-containing copper foil of the present invention.

The method of curing 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 manufacturing a printed wiring board using a curable resin composition, 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, printing is performed by the following method. A wiring board can be manufactured. 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 circuit board and the dry film of the present invention, the copper foil or the circuit board can be laminated at the same time. A printed wiring board can be manufactured by forming a pattern or via hole on a circuit board at a position corresponding to a predetermined position by laser irradiation or a drill 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.

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, and the copper foil is used as all or part of the wiring layer by a modified semi-additive process (MSAP) method. A circuit may be formed and a build-up wiring board may be manufactured. 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 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, instead of using the core substrate, a coreless build-up method in which resin layers and conductor layers are alternately laminated may be used.

<Electronic components>
The electronic component of the present invention has a cured product of the present invention, that is, a cured resin composition of the present invention, a resin layer of a dry film of the present invention, or a cured product of a resin layer of a copper foil with a resin of the present invention.
Examples of the electronic component include a permanent protective film of a printed wiring board, and among them, a solder resist layer, an interlayer insulating layer, and a coverlay of a flexible printed wiring board. In addition, electronic components include applications other than printed wiring boards, for example, passive components such as inductors.

The curable resin composition of the present invention can be suitably used for filling permanent holes in printed wiring boards, for example, filling holes such as through holes and via holes, in addition to the above-mentioned uses. It can also be used as a sealing material for semiconductor chips, as a material for copper-clad laminates (CCL) and prepregs.

Further, since the cured product of the curable resin composition of the present invention has excellent dielectric properties, it is considered that the transmission quality is good even in high frequency applications by using the cured product. Specific examples of high-frequency applications include millimeter-wave radars for automatic operation, millimeter-wave sensor substrates, high-speed communication-compatible mobile motherboards, and SLPs (Substation-Like PCBs) that form circuits using the Modified Semi-Additive Process (MSAP) method. ), Application processors (APs) for mobile and personal computers, high-frequency substrates for base station servers and routers, substrates for antennas, semiconductor encapsulation materials, and the like.

Further, the wiring board may be formed by bonding the wirings using the dry film of the present invention.

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

According to the present invention, it is possible to obtain a cured product having a low dielectric loss tangent, for example, it is possible to obtain less than 0.010 and even less than 0.006 at a frequency of 10 GHz and 23 ° C.
Further, according to the present invention, it is possible to obtain a cured product having a low dielectric constant, for example, it is possible to obtain less than 3.2 and even less than 3.0 at a frequency of 10 GHz and 23 ° C.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In the following, unless otherwise specified, "parts" and "%" mean parts by mass and% by mass.

((B) Synthesis of compound having active ester group)
[Synthesis Example 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 system was decompressed with nitrogen. It was replaced 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 while performing nitrogen gas purging, the inside of 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 phase in which the reaction product was dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was 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 a compound (B-1) having an active ester group in a toluene solution with a solid content of 65%.
The solid content-equivalent ester group equivalent of the obtained compound (B-1) having an active ester group was 223 g / mol.

[Synthesis Example 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, 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 sodium hydroxide compound (intermediate of B-2). The obtained benzyl-modified naphthalene compound (intermediate of B-2) was a black solid, and the hydroxyl group equivalent was 180 g / equivalent.
Next, 203.0 g of isophthalic acid chloride (number of moles of acid chloride group: 2.0 mol) and 1400 g of toluene were charged in another flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractional tube, and a stirrer. The inside of the system was replaced with reduced pressure nitrogen to dissolve it. Next, 96.0 g (0.67 mol) of α-naphthol and 240 g (intermediate of B-2) of a benzyl-modified naphthalene compound (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. And 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% aqueous sodium hydroxide 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 a compound (B-2) having an active ester group in a toluene solution with a solid content of 65% by mass. The solid content-equivalent ester group equivalent of the obtained compound (B-2) having an active ester group was 230 g / mol.

<1. Preparation of curable resin composition>
The various components shown in Table 1 below are kneaded and mixed at the ratios (parts by mass) shown in Table 1 to obtain the curable resin compositions of Examples 1 to 9 and Comparative Examples 1 and 2 for producing a film after curing. Prepared. The numerical values in Table 1 indicate parts by mass or% by mass (in terms of solid content).
As shown below, a test sample was prepared for each of the curable resin compositions, and the glass transition temperature (Tg), dielectric constant, dielectric loss tangent, and peel strength were measured and evaluated. The results are shown in Table 1.

<2. Preparation of film after curing>
Using a film applicator, the curable resin compositions of the above-mentioned Examples and Comparative Examples were applied onto the glossy surface of a copper foil (F2-WS manufactured by Furukawa Electric Co., Ltd., 18 μm thickness), and a hot air circulation method was applied. After drying in a drying oven at 90 ° C. for 10 minutes, and then curing at 200 ° C. for 60 minutes, the copper foil was peeled off, and the cured films of Examples 1 to 9 and Comparative Examples 1 and 2 having a thickness of about 40 μm, respectively. (Cured film) was prepared.

<3. Measurement of glass transition temperature (Tg)>
<2. Preparation of film after curing> The sample obtained 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 heating rate of 10 ° C./min, and the measurement was performed twice in succession, and the glass transition temperature (Tg), which is the intersection of two tangents having different linear thermal expansion coefficients, was evaluated.

The glass transition temperature was evaluated according to the following criteria.
◎: 175 ° C or higher 〇: Less than 175 ° C 170 ° C or higher ×: Less than 170 ° C

<4. Measurement of permittivity (Dk) and dielectric loss tangent (Df)>
The sample obtained in the above <Preparation of cured film> was cut out to a measurement size (size of 50 mm × 60 mm), and a dielectric constant of 10 GHz at 23 ° C. was used using an SPDR dielectric resonator and a network analyzer (both manufactured by Agilent). And the dielectric loss tangent was measured.
The dielectric constant (10 GHz) was evaluated according to the following criteria.
⊚: less than 3.0 〇: 3.0 or more and less than 3.2 ×: 3.2 or more The evaluation of the dielectric loss tangent (10 GHz) was performed according to the following criteria.
◎: Less than 0.006 〇: 0.006 or more to less than 0.010 ×: 0.010 or more

<5. Preparation of sample for peel strength measurement ＞
(1) Roughening treatment of laminated board Mech Co., Ltd. has both sides of a 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 an inner layer circuit is formed. 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, <1. Preparation of curable resin composition> The curable resin composition of each Example and Comparative Example was applied to the ultrathin copper foil surface of an ultrathin copper foil with a carrier (MT18Ex manufactured by Mitsui Kinzoku Co., Ltd., ultrathin copper 3 μm thick). It was applied onto the surface 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 Using a batch type vacuum pressure laminator MVLP-500 (manufactured by Meiki Co., Ltd.), copper foil with resin (2) was applied to both sides of the laminated board subjected to the roughening treatment (1). ) Resin composition coated surface 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 in a hot air circulation type drying oven at 200 ° C. for 60 minutes.

<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. The results are shown in Table 4.
⊚: 0.55 kN / m or more ○: less than 0.55 kN / m 0.4 kN / m or more ×: less than 0.4 kN / m

The details of the components in Table 1 are as follows.
EPICLON (registered trademark) EXA-835LV (manufactured by DIC, a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, liquid, epoxy equivalent: 165 g / eq)
NC-3000H (manufactured by Nippon Kayaku Co., Ltd., biphenyl novolac type epoxy resin, solid, epoxy equivalent: 290 g / eq)
B-1: Produced according to Synthesis Example 1 (active ester equivalent: 223 g / eq)
B-2: Produced according to Synthesis Example 2 (active ester equivalent: 230 g / eq)
SO-C2: Spherical silica treated with phenylaminosilane (average particle size: 0.5 μm, carbon amount per unit mass 0.18) (manufactured by Admatex)
Exp. BC10: (Block copolymer obtained from polypropylene glycol and polycaprolactone (molar ratio of about 49:51) manufactured by DIC, mass average molecular weight Mw (measured by GPC using polyethylene standard) about 9,000, melting point about 58 ° C., hydroxyl value 11-14 mgKOH / g, viscosity 4,000 mPa.s (75 ° C.))
Exp. BC20: (Block copolymer obtained from polytetramethylene glycol and polycaprolactone (molar ratio of about 44:56) manufactured by DIC, mass average molecular weight Mw (measured by GPC using polyethylene standard) about 9,000, Melting point: about 58 ° C., hydroxyl value: 11-14 mgKOH / g, viscosity: 4,000 mPa.s (75 ° C.))
Polypropylene glycol 3000: (manufactured by Junsei Chemical Co., Ltd., molecular weight 3,000)
Praxel 240: (manufactured by Daicel Corporation, polycaprolactone diol, molecular weight 4,000)
2E4MZ: 2-Ethyl-4-methylimidazole * 1: The ratio of the total amount of epoxy groups of (A) epoxy resin in the composition / (B) the total amount of active ester groups of the compound having active ester groups.

Examples 1 to 9 show that a cured product having high heat resistance, low dielectric constant, low dielectric loss tangent and excellent adhesion can be obtained from the curable resin composition of the present invention.

Claims (10)

(A) Epoxy resin,
(B) A compound having an active ester group,
(C) Inorganic filler and
(D) Polyester additive,
The curable resin composition comprising (D), wherein the polyester additive is a polymer having a polyalkylene glycol structure and an aliphatic polyester structure. The curing according to claim 1, wherein the blending amount of the (D) polyester additive is 1% by mass or more and 35% by mass or less with respect to the total mass of the (A) epoxy resin and the (B) compound having an active ester group. Sex resin composition. The curable resin composition according to claim 1 or 2, wherein the molar ratio of the polyalkylene glycol structure to the aliphatic polyester structure in the polyester additive (D) is in the range of 35 to 55: 65 to 45. Any one of claims 1 to 3, wherein 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 is 0.2 to 0.9. The curable resin composition according to the section. The compound having the active ester group (B) has the following general formula (1).

(In the formula, X ₁ is a group having an independent benzene ring or naphthalene ring, respectively, k represents 0 or 1, and n is an average of 0.05 to 2.5 in repeating units.) The curable resin composition according to any one of claims 1 to 4, which is a compound to be used. 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 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).
The curable resin composition according to any one of claims 1 to 4, which is a compound having a structural portion represented by and having a structure in which both ends thereof are monovalent aryloxy groups. A dry film comprising the curable resin composition according to any one of claims 1 to 6 as a resin layer. A copper foil with a resin, which comprises the curable resin composition according to any one of claims 1 to 6 as a resin layer on the copper foil or the copper foil with a carrier. The curable resin composition according to any one of claims 1 to 6, the resin layer of the dry film according to claim 7, or the cured product of the resin layer of the copper foil with resin according to claim 8. An electronic component having the cured product according to claim 9.